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  • 51.
    Biteus, Jonas
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Fault Isolation in Distributed Embedded Systems2007Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    To improve safety, reliability, and efficiency of automotive vehicles and other technical applications, embedded systems commonly use fault diagnosis consisting of fault detection and isolation. Since many systems are constructed as distributed embedded systems including multiple control units, it is necessary to perform global fault isolation using for example a central unit. However, the drawbacks with such a centralized method are the need of a powerful diagnostic unit and the sensitivity against disconnections of this unit.

    Two alternative methods to centralized fault isolation are presented in this thesis. The first method performs global fault isolation by a istributed sequential computation. For a set of studied systems, themethod gives, compared to a centralizedmethod, amean reduction inmaximumprocessor load on any unitwith 40 and 70%for systems consisting of four and eight units respectively. The second method instead extends the result of the local fault isolation performed in each unit such that the results are globally correct. By only considering the components affecting each specific unit, the extended result in each agent is kept small. For a studied automotive vehicle, the second method gives, compared to a centralized method, a mean reduction in the sizes of the results and the maximum processor load on any unit with 85 and 90% respectively.

    To perform fault diagnosis, diagnostic tests are commonly used. If the additional evaluation of tests can not improve the fault isolation of a component then the component is ready. Since the evaluation of a test comes with a cost in for example computational resources, it is valuable to minimize the number of tests that have to be evaluated before readiness is achieved for all components. A strategy is presented that decides in which order to evaluate tests such that readiness is achieved with as few evaluations of tests as possible.

    Besides knowing how fault diagnosis is performed, it is also interesting to assess the effect that fault diagnosis has on for example safety. Since fault tree analysis often is used to evaluate safety, this thesis contributes with a systematic method that includes the effect of fault diagnosis in fault trees. The safety enhancement due to the use of fault diagnosis can thereby be analyzed and quantified.

  • 52.
    Biteus, Jonas
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Mean Value Engine Model of a Heavy Duty Diesel Engine2002Rapport (Annet vitenskapelig)
    Abstract [en]

    A first implementation of a mean value engine model (MVEM) of a Heavy Duty Diesel (HDD) engine is described in this report. Framework and sub models are described. Where applicable ISO standards are followed. Verification against static measurements shows maximum model errors of about 6 % for mass flow and inlet/exhaust manifold pressures.

  • 53.
    Biteus, Jonas
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Frisk, Erik
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Nyberg, Mattias
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Condensed Representation of Global Diagnoses with Minimal Cardinality in Local Diagnoses2006Inngår i: 17th International Workshop on Principles of Diagnosis DX-06,2006, 2006Konferansepaper (Fagfellevurdert)
  • 54.
    Biteus, Jonas
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Frisk, Erik
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Nyberg, Mattias
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Distributed Diagnosis by Using a Condensed Local Representation of the Global Diagnoses with Minimal Cardinality2006Inngår i: 17 International Workshop on Principles of Diagnosis DX-06,2006, Spain: Spain , 2006Konferansepaper (Fagfellevurdert)
  • 55.
    Biteus, Jonas
    et al.
    Scania CV.
    Frisk, Erik
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Nyberg, Mattias
    Scania CV.
    Distributed Diagnosis Using a Condensed Representation of Diagnoses With Application to an Automotive Vehicle2011Inngår i: IEEE transactions on systems, man and cybernetics. Part A. Systems and humans, ISSN 1083-4427, E-ISSN 1558-2426, Vol. 41, nr 6, s. 1262-1267Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In fault detection and isolation, diagnostic test results are commonly used to compute a set of diagnoses, where each diagnosis points at a set of components which might behave abnormally. In distributed systems consisting of multiple control units, the test results in each unit can be used to compute local diagnoses while all test results in the complete system give the global diagnoses. It is an advantage for both repair and fault-tolerant control to have access to the global diagnoses in each unit since these diagnoses represent all test results in all units. However, when the diagnoses, for example, are to be used to repair a unit, only the components that are used by the unit are of interest. The reason for this is that it is only these components that could have caused the abnormal behavior. However, the global diagnoses might include components from the complete system and therefore often include components that are superfluous for the unit. Motivated by this observation, a new type of diagnosis is proposed, namely, the condensed diagnosis. Each unit has a unique set of condensed diagnoses which represents the global diagnoses. The benefit of the condensed diagnoses is that they only include components used by the unit while still representing the global diagnoses. The proposed method is applied to an automotive vehicle, and the results from the application study show the benefit of using condensed diagnoses compared to global diagnoses.

  • 56.
    Biteus, Jonas
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Nyberg, Mattias
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Dynamic Evaluation of Minimal Structurally Singular Sets2002Inngår i: CCSSE, Norrköping, Sweden 2002, 2002Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The problem of adding a residual component to an MSS set to gain a solvable model is studied. Two main approaches can be found, the dynamic and the static approach.

  • 57.
    Biteus, Jonas
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Nyberg, Mattias
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Residual Generators For Dae Systems Utilizing Minimal Subsets Of Model Equations2003Inngår i: Proceedings of IFAC Safeprocess’03, 2003Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A common approach to design diagnostic systems is to use residual generators. These generators are usually constructed considering all the model equations. However, there are several advantages of instead consider small subsets of model equations, so called minimal structurally singular (MSS) sets of equations. This paper presents a new method for finding residual generators for MSS sets. A special property of the MSS set, namely that it is minimally over determined, is utilized. Two approaches are considered, one which is based on the use of a dynamic numerical equation solver, and another which uses a static numerical equation solver. The approaches are demonstrated on a non-linear point-mass satellite system.

  • 58.
    Biteus, Jonas
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Nyberg, Mattias
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Frisk, Erik
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    An algorithm for computing the diagnoses with minimal cardinality in a distributed system2008Inngår i: Engineering applications of artificial intelligence, ISSN 0952-1976, E-ISSN 1873-6769, Vol. 21, nr 2, s. 269-276Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In fault diagnosis, the set of minimal diagnoses is commonly calculated. However, due to for example limited computation resources, the search for the set of minimal diagnoses is in some applications focused on to the smaller set of diagnoses with minimal cardinality. The key contribution in this paper is an algorithm that calculates the diagnoses with minimal cardinality in a distributed system. The algorithm is constructed such that the computationally intensive tasks are distributed to the different units in the distributed system, and thereby reduces the need for a powerful central diagnostic unit. © 2007 Elsevier Ltd. All rights reserved.

  • 59.
    Biteus, Jonas
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Nyberg, Mattias
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Frisk, Erik
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Åslund, Jan
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Determining a Component's Fault Status and the Status' Readiness2006Inngår i: IFAC Safeprocess06,2006, China: IFAC , 2006Konferansepaper (Fagfellevurdert)
  • 60.
    Biteus, Jonas
    et al.
    Power-Train Division, Scania.
    Nyberg, Mattias
    Power-Train Division, Scania.
    Frisk, Erik
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Åslund, Jan
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Determining the Fault Status of a Component and its Readiness, with a Distributed Automotive Application2009Inngår i: Engineering applications of artificial intelligence, ISSN 0952-1976, E-ISSN 1873-6769, Vol. 22, nr 3, s. 363-373Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In systems using only single-component tests, the fault status of a component is ready if a test only supervising the component has been evaluated. However, if plausibility tests that supervise multiple components are used, then a component can be ready before all tests supervising the component have been evaluated. Based on test results, this paper contributes with conditions on when a component is ready. The conditions on readiness are given for both centralized and distributed systems and are here applied to the distributed diagnostic system in an automotive vehicle.

  • 61.
    Bjelevac, Salko
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Karlsson, Peter
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Steering System Verification Using Hardware-in-the-Loop2015Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    In order for leading industrial companies to remain competitive, the process of product developement constantly needs to improve. In order to shorten development time -- that is the time from idea to product -- simulations of products in-house is becoming a popular method. This method saves money and time since expensive prototypes become unnecessary. Today the calibration of steering gears is done in test vehicles by experienced test drivers. This is a time consuming process that is very costly because of expensive test vehicles.

    This report investigates possibilities and difficulties with transfering the calibrations from field to rig. A steering rig has been integrated with a car simulation program. Comparisons between simulation in the loop (SIL) and hardware in the loop (HIL) have been made and differences between different configurations of steering gears have been evaluated. An automatic process including calibration of parameters, testing and analysis of the test results has been implemented. The work laid the foundation of calibration of steering parameters and showed correlation between calibration parameters and objective metrics.

  • 62.
    Björklund, Fredrik
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Karlström, Elin
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Enabling Testing of Lateral Active Safety Functions in a Multi-rate Hardware in the Loop Environment2017Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    As the development of vehicles moves towards shorter development time, new ways of verifying the vehicle performance is needed in order to begin the verification process at an earlier stage. A great extent of this development regards active safety, which is a collection name for systems that help both avoid accidents and minimize the effects of a collision, e.g brake assist and steering control systems. Development of these active safety functions requires extensive testing and verification in order to guarantee the performance of the functions in different situations. One way of testing these functions is to include them in a Hardware in the Loop simulation, where the involved hardware from the real vehicle are included in the simulation loop.

    This master thesis investigates the possibility to test lateral active safety functions in a hardware in the loop simulation environment consisting of multiple subsystems working on different frequencies. The subsystems are all dependent of the output from other subsystems, forming an algebraic loop between them. Simulation using multiple hardware and subsystems working on different frequencies introduces latency in the simulation. The effect of the latency is investigated and proposed solutions are presented. In order to enable testing of lateral active safety functions, a steering model which enables the servo motor to steer the vehicle is integrated in the simulation environment and validated.

  • 63.
    Blomgren, Martin
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Modeling and control of engaging gears in gearboxes without synchromesh towards specific angles between gear and coupling sleeve2019Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    When engaging a new gear in an automated manual transmission (AMT) the gear needs to be synchronized with the main shaft's angular velocity in the gearbox. This is so that the parts can be connected through a cog wheel and torque can be transferred. To synchronize the angular velocities, mechanical synchronization components can be used. These components synchronize the velocities during the engagement and can be used with larger differences in angular velocities. Should no mechanical synchronization components be used it puts higher demands on the components rotating at similar velocities to avoid mechanical wear and ensure that the gear can be engaged. In today's systems without mechanical synchronization components the gear is engaged when the angular velocities are within a certain difference. This leads to random angle connections between the cogs and gaps that are to be engaged on the gear and main shaft. This can lead to extended or incomplete engages should the components connect cog to cog.

    This thesis evaluates the possibility to control the angle at which the components connect by using existing sensor signals in the studied system and known parameters. A model of the system is created and simulated to evaluate the probability of predicting the system over the gear engage. Results indicate that it is possible to predict the connection angle close enough to its real value so that a control strategy could be implemented to control the angle to some level.

  • 64.
    Bodin, Johannes
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Development of Push Control Strategy for Diesel-Electric Powertrains2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    In diesel-electric powertrains, the wheels are mechanically decoupled from the internal combustion engine (ICE). The conventional control approach for such a powertrain is to let the driver control the traction motor while the ICE realizes speed control, causing power to be pulled through the powertrain. An alternative approach is to push power forward by letting the driver control the ICE instead. In this thesis, a conceptual simulation model of a diesel-electric powertrain is compiled and the charcteristics of this novel approach investigated. It is concluded that the new approach makes full ICE power utilization possible even with engine performance reductions present, and also that it handles load prioritization in a natural way. However, takeoff from standstill and low-speed driving become difficult due to the effective gear ratio growing towards infinity for decreasing vehicle speed, causing high traction torques at low speed.

  • 65.
    Brischetto, Mathias
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Improved Functionality for Driveability During Gear-Shift: A Predictive Model for Boost Pressure Drop2015Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Automated gear-shifts are critical procedures for the driveline as they are demanded to work as fast and accurate as possible. The torque control of a driveline is especially important for the driver’s feeling of driveability. In the case of gear-shifts and torque control in general, the boost pressure is key to achieve good response and thereby a fast gear-shift.

    An experimental study is carried out to investigate the phenomena of boost pressure drop during gear-shift and gather data for the modelling work. Results confirm the stated fact on the influence of boost pressure drop on gear-shift completion time and also indicate a clear linear dependence between initial boost pressure and the following pressure drop.

    A dynamic predictive model of the engine is developed with focus on implementation in a heavy duty truck, considering limitations computational complexity and calibration need between truck configurations. The resulting approach is based on a mean value modelling scheme that uses engine control system parameters and functions when possible. To be able to be predictive, a model for demanded torque and engine speed during the gear-shift is developed as reference inputs to the simulation. The simulation is based on a filling and emptying process throughout the engine dynamics, and yields final values of several engine variables such as boost pressure.

    The model is validated and later evaluated in comparison to measurements gathered in test vehicle experiments and in terms of robustness to input and model deviations. Computer simulations yield estimations of the boost pressure drop within acceptable limits. Consid- ering estimations used prior to this thesis the performance is good. Input deviations and modelling inaccuracies are found to inflict significant but not devastating deviations to the model output, possibly more over time with ageing of hardware taken into account.

    Final implementation in a heavy duty truck ecu is carried out with results indicating that the current implementation of the module is relatively computationally heavy. At the time of ending the thesis it is not possible to analyse its performance further, and it is suggested that the module is optimized in terms of computational efficiency. 

  • 66.
    Broomhead, Timothy James
    et al.
    Department of Mechanical Engineering, The University of Melbourne, Australia.
    Manzie, Chris
    Department of Mechanical Engineering, The University of Melbourne, Australia.
    Eriksson, Lars
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Brear, Michael
    Department of Mechanical Engineering, The University of Melbourne, Australia.
    Hield, Peter
    Defence Science and Technology Organisation, Australia.
    A Robust Model Predictive Control Framework for Diesel Generators2014Inngår i: Proceedings of 19th IFAC World Congress / [ed] Edward Boje; Xiaohua Xia, International Federation of Automatic Control (IFAC) , 2014, Vol. 47, s. 11848-11853Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A constraint tightened linear-time-varying MPC framework is proposed with applications in power tracking for variable and fixed speed generators. Current constraint tightening approaches are extended to allow for practical applications where future system representations are unknown. The resulting control structure is shown to be robustly feasible under given conditions. Knowledge about the geometry of system constraints is exploited to obtain a computationally efficient method of computing tightened sets online. A simulation study is presented demonstrating the ability of the controller to handle modelling error and demonstrate tracking of a commanded power profile.

  • 67.
    Brugård, Jan
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Eriksson, Lars
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Nielsen, Lars
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Mean Value Engine Modeling of a Turbo Charged Spark Ignited Engine: A Principle Study2001Rapport (Annet vitenskapelig)
    Abstract [en]

    Object oriented modeling of physical systems is an interesting paradigm, which has the potential to offer reusable models and model components. The aim of this study i to investigate how to build mean value models for automotive engines. MathModelica, a modeling tool for the object oriented modeling language Modelica, is used in this study. Several sub models have been developed for the different parts of the engine. Th models cover the air filter, intercooler, throttle, base engien, exhaust system, compressor, turbine, turbine shaft, and volumes. It is shown how the components can be connected to form both turbo charged engines as well as a naturally aspirated engines, which shows that the paradigm is applicable for the modeling and confirms the modeling principle. One problem that has popped up att several occasions is the selection of initial conditions for the simulation. Especially when restrictions with low pressure drops are connected between two volumes, the simulation engine has problems finding initial conditions. The models have been compared to measured engine data collected at a test bench in Vehicular Systems laboratory at Linköping University. The agreement with measurement data is good and the models work as expected.

  • 68.
    Buffoni-Rogovchenko, Lena
    et al.
    Linköpings universitet, Institutionen för datavetenskap, PELAB - Laboratoriet för programmeringsomgivningar. Linköpings universitet, Tekniska högskolan.
    Fritzson, Peter
    Linköpings universitet, Institutionen för datavetenskap, PELAB - Laboratoriet för programmeringsomgivningar. Linköpings universitet, Tekniska högskolan.
    Nyberg, Mattias
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Garro, Alfredo
    University of Calabria, Italy.
    Tundis, Andrea
    University of Calabria, Italy.
    Requirement Verification and Dependency Tracing During Simulation in Modelica2013Inngår i: EUROSIM '13, IEEE Press, 2013, s. 561-566Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Requirement verification is an important part of the development process, and the increasing system complexity has exacerbated the need for integrating this step into a formalized model driven development process, providing a dedicated methodology as well as tool support. In this paper the authors propose an extension for Modelica, an equation-based language for system modeling, that will allow to represent system requirements in the same formalism as the design model, thus reducing the need for transformations between different specialized formalisms, lowering maintenance and modification costs, and benefitting from the expression and simulation capabilities, as well as extensive tool support of Modelica. The object-oriented nature of the approach provides the advantages of modular design and hierarchical structuring of the requirement model. This paper also illustrates, with the help of an example, how requirement verification can be used alongside the simulation process to trace the components responsible for requirement violations. To this end, we introduce a formalism for expressing relationships between components and requirements, as well as a tracing algorithm.

  • 69.
    Carlsson, Carin
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Modeling and Experimental Validation of a Rankine Cycle Based Exhaust WHR System for Heavy Duty Applications2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    To increase the efficiency of the engine is one of the biggest challenges for heavy vehicles. One possible method is the Rankine based Waste Heat Recovery. Crucial for Rankine based Waste Heat Recovery is to model the temperature and the state of the working fluid. If the state of the working fluid is not determined, not only the efficiency of the system could be decreased, the components of thesystem might be damaged.A Simulink model based on the physical components in a system developed by Scania is proposed. The model for the complete system is validated against a reference model developed by Scania, and the component models are further validated against measurement data. The purpose of the model is to enable model based control, which is not possible with the reference model. The main focus on the thesis is to model the evaporation and condensation to determine state and temperature of the working fluid. The developed model is compared to a reference model with little differences for while stationary operating for both the components and the complete system. The developed model also follows the behavior from measurement data. The thesis shows that two phase modeling in Simulink is possible with models based on the physical components.

  • 70.
    Carlsson, Petter
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Coordinated Model Based Thottle and Turbo Control2013Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Downsizing and turbocharging is one way to meet the high demands on fuel consumptionand performance on todays engines. The air-path system in a turbochargedspark ignited engine is a complex system and because the intake manifoldpressure is tightly connected with the engine torque a consistent and robustcontrol is needed. The control strategy utilizes two control loops, one wastegateactuator to control the intercooler pressure and one throttle actuator to controlthe intake manifold pressure. These pressures are coupled, making both actuatorsaffect both pressures. Because of the time delay and the dynamics in the actuatorsand the system dynamics between the wastegate and the intercooler pressure thecontroller overreacts causing a pressure overshoot and sometimes oscillations. Theoscillatory behavior is caused by both actuators trying to minimize their respectivecontrol error, affecting the others pressure. The delay in the system dynamicscauses the two controllers to enter a state where they counteract each other.A compensation strategy is suggested, which estimates the intercooler pressurederivative and uses that to predict the future intercooler pressure. The compensationstrategy shows good performance in simulations, reducing the overshoots andeliminating the oscillations.

  • 71.
    Chen, Qi
    et al.
    Center of Automotive Research, Ohio State University, USA.
    Qadeer, Ahmed
    Center of Automotive Research, Ohio State University, USA.
    Rizzoni, Giorgio
    Center of Automotive Research, Ohio State University, USA.
    Frisk, Erik
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Zhai, Hua
    Center of Automotive Research, Ohio State University, USA.
    Model-Based Fault Diagnosis of an Automated Manual Transmission Shifting Actuator2015Inngår i: Proceedings of the 9th IFAC Symposium on Fault Detection, Supervision and Safety of Technical Processes Safeprocess'15, Elsevier, 2015, Vol. 48, nr 21, s. 1479-1484Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a model-based methodology of residuals design for fault diagnosis of an Automated Manual Transmission (AMT) shifting actuator by employing Structural Analysis (SA). A group of sensors are suggested to obtain the maximal capability of Fault Detection and Isolation (FDI) after performing SA. Then, Minimal Structurally Over-determined (MSO) sets are identified to generate four residuals. To ensure stable and robust residuals, concepts from Analytical Redundant Relation (ARR) and observer-based parameter evaluation techniques are utilized. The proposed FDI scheme for AMT actuator has been successfully tested and verified using numerical simulations in MATLAB Simulink. The presented scheme offers a cost effective solution by using only two sensors to monitor five critical faults in AMT actuator.

  • 72.
    Chew, Weng Chuen
    et al.
    Monash University, Malaysia.
    Ng, Kok Yew
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten. Monash University, Malaysia.
    Khoo, BH
    Monash University, Malaysia.
    ReCon-AVe: Remote Controlled Automobile Vehicle For Data Mining And Analysis2015Inngår i: 39TH ANNUAL IEEE COMPUTERS, SOFTWARE AND APPLICATIONS CONFERENCE (COMPSAC 2015), VOL 2, IEEE , 2015, s. 569-574Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper explores the control of an automobile mounted with a BlackWidow 1.0 microcontroller from a remote location using a smartphone or a computer as a data mining and analysis device as well as for the purposes of first response search and rescue during a disaster relief operation. Custom application programs; ReCon-A for the Android platform and ReCon-V for Microsoft Windows are designed specifically for this project to control the ReCon-AVe vehicle. It is found that the remote controllers are able to control the automobile from distance of more than 20m away in indoor conditions using direct connections. In outdoor conditions, communications using the computer as the remote controller can reach up to 35m while using the smartphone can achieve up to 25m away. Other than that, tests show that the response time of ReCon-AVe is less than 60ms in indoor conditions and 85ms in outdoor conditions. In addition, it can provide visual feedback to the user at a minimum 16fps that also comes with a panning capability. Apart from that, ReCon-AVe proves its capabilities to acquire two different types of sensory data obtained from sensors and then have them transferred back to the user wirelessly for data mining and analysis.

  • 73.
    Criscuolo, Ivan
    et al.
    Department of Mechanical Engineering, University of Salerno, Fisciano, Italy.
    Leufvén, Oskar
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Thomasson, Andreas
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Eriksson, Lars
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Model-Based Boost Pressure Control with System Voltage Disturbance Rejection2011Inngår i: Proceedings of the 18th IFAC World Congress, 2011 / [ed] Bittanti, Sergio, Cenedese, Angelo, Zampieri, Sandro, International Federation of Automatic Control (IFAC) , 2011, s. 5058-5063Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Actuation systems for automotive boost control incorporate a vacuum tank and PWM controlled vacuum valves to increase the boosting system flexibility. Physical models for the actuator system are constructed using measurement data from a dynamometer with an engine having a two stage turbo system. The actuator model is integrated in a complete Mean Value Engine Model and a boost pressure controller is constructed. The developed model is used as basis for a nonlinear compensator, that is capable of rejecting disturbances from system voltage. An IMC based boost pressure controller is developed for the vacuum actuator and engine by using the engine model and then tested on the test cell. The controller performance is quantified and system voltage disturbance rejection is demonstrated.

  • 74.
    Dagson, Josef
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Nissilä Källström, Samuel
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Air Leakage Diagnosis in Heavy Duty Truck Engines with EGR and VGT2009Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Scania CV AB is a leading company within development and production of buses, trucks as well as industrial and marine engines.

    New environmental and safety legislations continuously demand higher quality from the products. An upcoming European legislation, Euro 6, implies that gas leakages from truck engines should be detected while driving. If the source of the leakage is not only detected, but also isolated, that is separated from other faults, the adjustments in the workshop goes faster since there is no need for leakage localisation. A faster reparation increases the up-time, i.e. the amount of time that the truck can be used.

    This master thesis work uses current methods developed at Scania for residual generation to perform model-based leakage diagnosis. In this work, measurements are gathered for dierent sensor faults and two leakages. The measurements are used to evaluate the actual performance of the resulting diagnosis system.

    The result, based on the residuals generated by the method, shows that leakages on the boost-side and the exhaust-side can be detected, and isolated from faults in the pressure sensors on the boost-side and the exhaust-side. The isolation of these four faults is considered the hardest to achieve among sensor faults and leakages why the full isolation performance is promising. Further measurements are needed to determine the full isolation performance of the diagnosis system.

    The resulting system is reasoned to be suitable for execution in real time on-board the truck.

  • 75.
    Daniels, Oskar
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Driver-truck models for software-in-the-loop simulations2014Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    By using vehicle-to-vehicle communication, vehicles can cooperate in many waysby sending positions and other relevant data between each other. One popularexample is platooning where many, especially heavy vehicles, drive on a trailwith short distances resulting in a reduction of air resistance. To achieve a goodefficiency of the platooning it is required that vehicle fleets are coordinated, sothat the percentage of time for driving in platoon is maximized without affectingthe total driving time and distance too much. For large fleets, this is a complexoptimization problem which would be difficult to solve by only using the realworld as the test environment.

    To provide a more adaptable test environment for the communication and platooningcoordination, an augmented reality with virtual vehicles (“Ghost trucks")with relevant communication abilities are developed. In order to realise the virtualtesting environment for trucks, Scania initiated a project that could be dividedinto the workload of three master theses. This thesis involved the part ofdeveloping the virtual vehicles, which include the development of a truck modeland a driver model.

    The developed truck model consists of a single track vehicle model and severalpowertrain models of different complexity provided by Scania. Additionally, thedriver model consists of steering wheel and speed controls in order to keep thetruck on a safe distance from the lead truck and stay on a preferred lane. The keyfeature of the driver-truck model is its modular design, which provides great flexibilityin selecting the level of detail for each component. The driver-truck modelcan be duplicated and simulated together in real time and performs platooningwith each other in a road system based on the real world. As the driver-truckmodel is module based, it can easily be extended for future purposes with morecomplex functions.

    The driver-truck model is implemented in Simulink and the simulation performancefor different model complexity is evaluated. It is demonstrated that theflexibility of the developed model allows a balanced decision to be made betweenrealistic truck behavior and simulation speed. Furthermore, multi-truck simulationsare performed using the model, which demonstrate the effectiveness of themodel in the evaluation of truck platooning operations.

  • 76.
    Duhan, Isac
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Design of Automated Generation of Residual Generators for Diagnosis  of Dynamic Systems2011Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    Diagnosis and Supervision of technical systems is used to detect  faults when they occur. To make a diagnosis, tests based on residuals can be used. Residuals are used to compare observations of  the system with a model of the system, to detect inconsistencies.

    There are often many different types of faults which affects the  state of the system. These states are modeled as fault modes. The  difference between fault modes are the presence of faults in the  model. For each fault mode a different set of model equations is  used to describe the behaviour of the real system. When doing fault  diagnosis in real time it is good, and sometimes vital, to be able to change fault mode of the model, when a fault suddenly occurs in the real system. If multiple faults can occur the number of  combinations of faults is often so big, even for relatively small  systems, that residuals for all fault modes can not be prepared. To  handle this problem, the residuals are to be generated when they are  needed.

    The main task in this thesis has been to investigate how residuals  can be automatically generated, given a fault mode with a  corresponding model. An algorithm has been developed and to verify  the algorithm a model of a satellite power system, called  ADAPT-Lite, has been used. The algorithm has been made in two versions. One is focusing on numerical calculations and the other is  allowing algebraical calculations. A numerical algorithm is preferred in an automatized process because  of generally shorter calculation times and the possibility to apply it to systems which can not be solved algebraically but the  algebraical algorithm gives slightly more accurate results in some  cases.

  • 77.
    Dushku, Mergim
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Kokko Ekholm, Julius
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Charge into the Future Grid: Optimizing Batteries to Support the Future Low-Voltage Electrical Grid2019Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The increase in electric vehicles and photovoltaic power production may introduce problems to the low-voltage distribution grid. With a higher number of electric vehicles, their accumulated charging power might breach the lowest allowed voltage level of the grid. Photovoltaic-modules can on the other hand exceed the highest allowed voltage level, by producing high accumulated power when the solar irradiance is high. Normally, electric distribution companies in Sweden reinforce the existing grid with more resilient infrastructure, such as stronger and larger cables or transformer stations. This is however a costly and time-consuming solution, which could be solved by using alternative means such as already existing resources.

    This Master's Thesis investigates how smart charging of batteries can support the low-voltage electrical grid with the increase in electric vehicles and photovoltaic power production. To do this, an optimization tool has been developed in Matlab. An existing model of a low-voltage grid is combined with the developed tool, where controllable batteries and photovoltaic-modules can be placed at specific households in the grid. The controllable batteries belong to either electric vehicles or stationary battery systems, and are intended to support the grid by the means of either reducing peak load powers, voltage variations, or a trade-off between them. Furthermore, this thesis investigates the maximum electric vehicle capability for a specific low-voltage electrical grid in Sweden.

    From the results, it can be concluded that smart charging of batteries can reduce the peak loads as well as voltage variations. The reduction of voltage variations for the entire low-voltage grid is greatest during the summer, when photovoltaic production generally is at its highest. The results also show that a stationary battery system can reduce the voltage variations to a greater extent, compared to an electric vehicle. Also, the introduction of multiple controllable batteries allows further support of the low-voltage grid. Regarding the maximum electric vehicle capability, the results show that the placement of the vehicles and the charging power strongly affect the maximum number of electric vehicles the low-voltage grid can manage.

  • 78.
    Düstegör, Dilek
    et al.
    LAIL Ecole Polytechnique Universitaire de Lille, France.
    Coquempot, Vincent
    LAIL Ecole Polytechnique Universitaire de Lille, France.
    Staroswiecki, Marcel
    LAIL Ecole Polytechnique Universitaire de Lille, France.
    Frisk, Erik
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Isolabilité structurelle des défaillances - Application à un modèle de vanne2004Inngår i: Journal européen des systèmes automatisès, ISSN 1269-6935, Vol. 39, nr 1, s. 103-124Artikkel i tidsskrift (Fagfellevurdert)
  • 79. Düstegör, Dilek
    et al.
    Frisk, Erik
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Coquempot, Vincent
    Krysander, Mattias
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Staroswiecki, Marcel
    Structural Analysis of Fault Isolability in the DAMADICS benchmark2006Inngår i: Control Engineering Practice, ISSN 0967-0661, E-ISSN 1873-6939, Vol. 14, nr 6, s. 597-608Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Structural analysis is a powerful tool for early determination of fault detectability/fault isolability possibilities. It is shown how different levels of knowledge about faults can be incorporated in a structural fault isolability analysis and how they result in different isolability properties. The results are evaluated on the DAMADICS valve benchmark model. It is also shown how to determine which faults in the benchmark that need further modelling to get desired isolability properties of the diagnosis system.

  • 80.
    Edlund, Simon
    et al.
    Nokia Svenska AB, Linköping, SWEDEN.
    Eriksson, Lars
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Nielsen, Lars
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Pettersson, Magnus
    SCANIA AB, Södertälje. SWEDEN.
    A Real-Time Platform for Collaboration Projects in Power Train Modeling and Control1999Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The requirements on research and development in automotive control are growing fast, and therefore convenient and efficient ways to make prototype experiments and demonstrations are sought for. Collaboration projects put some additional constraints on the experimental system used due to issues of safety and secrecy. These requirements are outlined, a real-time platform is developed, and experiences from some collaboration projects between industry and academia are discussed.

  • 81.
    Ekberg, Kristoffer
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Effects of Non Ideal Inlet and Outlet Pipes on Measured Compressor Efficiency2015Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The thesis is about investigating the inlet and outlet pipes effect on the compressors measured performance. From measurements made in a gas stand, a thermodynamic model is to be created and the compressor efficiency further investigated. The temperatures and pressures entering and leaving the compressor does not have to be the same as the temperatures measured in the gasstand, because of the thermodynamics of the pipes that connects the measurement equipment and the compressor. During a gasstand test the turbocharger is connected in a test bench, it is connected with pipes on both the compressor and turbine side, to simulate the hot exhaust gases from the car engine and the pressure increase over the compressor. The air entering and leaving the turbocharger through the different pipes is controlled and all the entering and leaving temperatures and pressures are measured. Gasstand data from different tests are available during the thesis, one specific turbocharger is used as references during the modeling. Models of the inlet and outlet pipes are created and connected to a compressor model. The model is controlled to give the same mass flow as the measured data, to ensure that the work cycle is followed. The effects of the non ideal inlet and outlet pipes on measured compressor efficiency is studied with help of this model and the main impacts on the measured compressor efficiency are discovered. The result shows that the measured values used to calculate the compressor efficiency could change, depending on the measurement positions on the inlet and outlet pipes. 

  • 82.
    Ekberg, Kristoffer
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Eriksson, Lars
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Improving Fuel Economy and Acceleration by Electric Turbocharger Control for Heavy Duty Long Haulage2017Inngår i: IFAC PAPERSONLINE, ELSEVIER SCIENCE BV , 2017, Vol. 50, nr 1, s. 11052-11057Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Todays vehicle industry is converging more and more to electrification of vehicles, introducing electrical architectures to cooperate side by side with the combustion engine. This paper investigates the potential of using an electric turbocharger in a long haulage application during highway driving. A charge sustainable control strategy is developed, implemented, tuned, and evaluated on a heavy duty truck model. The benefits of using an electrical turbocharger on a heavy duty diesel truck, from a long haulage perspective, are evaluated. By calibrating the implemented controller, long haulage driving routes can be charge sustainable and consume less fuel than a conventional truck with fix turbine geometry, the fuel savings for the simulated case is 0.9%. (C) 2017, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

  • 83.
    Ekberg, Kristoffer
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Eriksson, Lars
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Sivertsson, Martin
    Linköpings universitet, Institutionen för systemteknik. Linköpings universitet, Tekniska fakulteten.
    Cycle Beating - An Analysis of the Boundaries During Vehicle Testing2016Inngår i: IFAC PAPERS ONLINE, ELSEVIER SCIENCE BV , 2016, Vol. 49, nr 11, s. 657-664Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Todays vehicle industry is strictly controlled by environmental legislations. The vehicle industry is spending much money out reducing the fuel consumption and fulfilling the emission requirements to make sales possible in different regions in the world. Before introducing; a vehicle on the market, it is tested according to standardized driving cycles to specify the vehicle pollutant emissions and fuel consumption. These cycles allow some deviation from the reference vehicle speed during tests, e.g. NEDC allows deviations of +/- 2 km/h and +/- 1 s. This paper uses dynamic programming to find fuel optimal velocity profiles, given the allowed deviations of +/- 2 km/h and +/- 1 s from reference speed during drive cycle test. By taking advantage of the allowed deviation, the fuel consumption can be reduced by up to 16.56 % according to model results, ruoriing NEDC if gear selections are unrestricted (i.e. using automatic gearbox), and up to 5.90 % if changing gears according to the specifications in the drive cycle. Two different optimization goals are investigated, minimum amount of mass fuel consumed and best mileage. (C) 2016, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

  • 84.
    Eneroth, Erik
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Controller Design Enabling Automated and Fuel-Efficient Driving Strategies for Heavy Duty Vehicles in Urban Environments2015Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The automative industry drives the development towards more autonomous vehicles, this because of both safety and energy conservation reasons. This thesis focuses on solutions to lower the fuel consumption for heavy duty vehicles, which is more and more requested. Both due to increasing fuel costs and to greater environmental awareness. Through extensive simulations with a vehicle model, developed at and provided by Scania CV AB, different driving strategies are evaluated and analysed. This determined how to achieve a low fuel consumption when driving heavy vehicle in an urban environment. The simulations shows that the fuel consumption can be lowered by coasting the vehicle when deceleration and thus minimize the use of the brakes. One should also when possible, select a higher gear to lower the fuel consumption due to engine friction. These strategies are used to develop a controller which lowers the fuel consumption without increasing the trip time for the vehicle. The controller is able to alter the velocity of the vehicle within a reference window which results in both a lower fuel consumption and a shorter trip time for the driving cycle used.

  • 85.
    Engman, Jimmy
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Model Predictive Control for Series-Parallel Plug-In Hybrid Electrical Vehicle2011Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The automotive industry is required to deal with increasingly stringent legislationfor greenhouse gases. Hybrid Electric Vehicles, HEV, are gaining acceptance as thefuture path of lower emissions and fuel consumption. The increased complexityof multiple prime movers demand more advanced control systems, where futuredriving conditions also becomes interesting. For a plug-in Hybrid Electric Vehicle,PIHEV, it is important to utilize the comparatively inexpensive electric energybefore the driving cycle is complete, this for minimize the cost of the driving cycle,since the battery in a PIHEV can be charged from the grid. A strategy with lengthinformation of the driving cycle from a global positioning system, GPS, couldreduce the cost of driving. This by starting to blend the electric energy with fuelearlier, a strategy called blended driving accomplish this by distribute the electricenergy, that is charged externally, with fuel over the driving cycle, and also ensurethat the battery’s minimum level reaches before the driving cycle is finished. Astrategy called Charge Depleting Charge Sustaining, CDCS, does not need lengthinformation. This strategy first depletes the battery to a minimum State of Charge,SOC, and after this engages the engine to maintain the SOC at this level. In thisthesis, a variable SOC reference is developed, which is dependent on knowledgeabout the cycle’s length and the current length the vehicle has driven in the cycle.With assistance of a variable SOC reference, is a blended strategy realized. Thisis used to minimize the cost of a driving cycle. A comparison between the blendedstrategy and the CDCS strategy was done, where the CDCS strategy uses a fixedSOC reference. During simulation is the usage of fuel minimized; and the blendedstrategy decreases the cost of the driving missions compared to the CDCS strategy.To solve the energy management problem is a model predictive control used. Thedesigned control system follows the driving cycles, is charge sustaining and solvesthe energy management problem during simulation. The system also handlesmoderate model errors.

  • 86.
    Eriksson, Daniel
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Diagnosability analysis and FDI system design for uncertain systems2013Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Our society depends on advanced and complex technical systems and machines, for example, cars for transportation, industrial robots in production lines, satellites for communication, and power plants for energy production. Consequences of a fault in such a system can be severe and result in human casualties, environmentally harmful emissions, high repair costs, or economical losses caused by unexpected stops in production lines. Thus, a diagnosis system is important, and in some applications also required by legislations, to monitor the system health in order to take appropriate preventive actions when a fault occurs. Important properties of diagnosis systems are their capability of detecting and identifying faults, i.e., their fault detectability and isolability performance.

    This thesis deals with quantitative analysis of fault detectability and isolability performance when taking model uncertainties and measurement noise into consideration. The goal is to analyze diagnosability performance given a mathematical model of the system to be monitored before a diagnosis system is developed. A measure of fault diagnosability performance, called distinguishability, is proposed based on the Kullback-Leibler divergence. For linear descriptor models with Gaussian noise, distinguishability gives an upper limit for the fault to noise ratio of any linear residual generator. Distinguishability is used to analyze fault detectability and isolability performance of a non-linear mean value engine model of gas flows in a heavy duty diesel engine by linearizing the model around different operating points.

    It is also shown how distinguishability is used for determine sensor placement, i.e, where sensors should be placed in a system to achieve a required fault diagnosability performance. The sensor placement problem is formulated as an optimization problem, where minimum required diagnosability performance is used as a constraint. Results show that the required diagnosability performance greatly affects which sensors to use, which is not captured if not model uncertainties and measurement noise are taken into consideration.

    Another problem considered here is the on-line sequential test selection problem. Distinguishability is used to quantify the performance of the different test quantities. The set of test quantities is changed on-line, depending on the output of the diagnosis system. Instead of using all test quantities the whole time, changing the set of active test quantities can be used to maintain a required diagnosability performance while reducing the computational cost of the diagnosis system. Results show that the number of used test quantities can be greatly reduced while maintaining a good fault isolability performance.

    A quantitative diagnosability analysis has been used during the design of an engine misfire detection algorithm based on the estimated torque at the flywheel. Decisions during the development of the misfire detection algorithm are motivated using quantitative analysis of the misfire detectability performance. Related to the misfire detection problem, a flywheel angular velocity model for misfire simulation is presented. An evaluation of the misfire detection algorithm show results of good detection performance as well as low false alarm rate.

    Delarbeid
    1. A method for quantitative fault diagnosability analysis of stochastic linear descriptor models
    Åpne denne publikasjonen i ny fane eller vindu >>A method for quantitative fault diagnosability analysis of stochastic linear descriptor models
    2013 (engelsk)Inngår i: Automatica, ISSN 0005-1098, E-ISSN 1873-2836, Vol. 49, nr 6, s. 1591-1600Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Analyzing fault diagnosability performance for a given model, before developing a diagnosis algorithm, can be used to answer questions like “How difficult is it to detect a fault fi?” or “How difficult is it to isolate a fault fi from a fault fj?”. The main contributions are the derivation of a measure, distinguishability, and a method for analyzing fault diagnosability performance of discrete-time descriptor models. The method, based on the Kullback–Leibler divergence, utilizes a stochastic characterization of the different fault modes to quantify diagnosability performance. Another contribution is the relation between distinguishability and the fault to noise ratio of residual generators. It is also shown how to design residual generators with maximum fault to noise ratio if the noise is assumed to be i.i.d. Gaussian signals. Finally, the method is applied to a heavy duty diesel engine model to exemplify how to analyze diagnosability performance of non-linear dynamic models.

    sted, utgiver, år, opplag, sider
    Elsevier, 2013
    Emneord
    Fault diagnosability analysis; Fault detection and isolation; Model-based diagnosis
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-89941 (URN)10.1016/j.automatica.2013.02.045 (DOI)000319540500007 ()
    Tilgjengelig fra: 2013-03-11 Laget: 2013-03-11 Sist oppdatert: 2019-09-23bibliografisk kontrollert
    2. Using quantitative diagnosability analysis for optimal sensor placement
    Åpne denne publikasjonen i ny fane eller vindu >>Using quantitative diagnosability analysis for optimal sensor placement
    2012 (engelsk)Inngår i: Proceedings of the 8th IFAC Safe Process, Mexico City, Mexico / [ed] Carlos Manuel Astorga-Zaragoza, Arturo Molina Gutierrez and Adriana Aguilera-Gonzalez, Curran Associates, Inc., 2012, s. 940-945Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    A good placement of sensors is crucial to get good performance in detecting and isolating faults. Here, the sensor placement problem is cast as a minimal cost optimization problem. Previous works have considered this problem with qualitative detectability and isolability specifications. A key contribution here is that quantified detectability and isolability performance is considered in the optimization formulation. The search space for the posed optimization problem is exponential in size, and to handle complexity a greedy optimization algorithm that compute optimal sensor positions is proposed. Two examples illustrate how the optimal solution depends on the required quantified diagnosability performance and the results are compared to the solutions using a deterministic method.

    sted, utgiver, år, opplag, sider
    Curran Associates, Inc., 2012
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-89942 (URN)10.3182/20120829-3-MX-2028.00196 (DOI)978-390282309-0 (ISBN)
    Konferanse
    8th IFAC Symposium on Fault Detection, Supervision and Safety of Technical Processes, SAFEPROCESS 2012; Mexico City; Mexico
    Tilgjengelig fra: 2013-03-11 Laget: 2013-03-11 Sist oppdatert: 2019-09-23bibliografisk kontrollert
    3. A sequential test selection algorithm for fault isolation
    Åpne denne publikasjonen i ny fane eller vindu >>A sequential test selection algorithm for fault isolation
    2012 (engelsk)Inngår i: Proceedings of the 10th European Workshop on Advanced Control and Diagnosis, ACD 2012, Copenhagen, Denmark, 2012Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    A sequential test selection algorithm is proposed which updates the set of active test quantities depending on the present minimal candidates. By sequentially updating the set of active test quantities, computational time and memory usage can be reduced. If test quantities are generated on-line, a sequential test selection algorithm gives information about which test quantities that should be created. The test selection problem is defined as an optimization problem where a set of active test quantities is chosen such that the cost is minimized while the set fulfills a required minimum detectability and isolability performance. A quantitative diagnosability measure, distinguishability, is used to quantify diagnosability performance of test quantities. The proposed test selection algorithm is applied to a DC-circuit where the diagnosis algorithm generates residuals on-line. Experiments show that the sequential test selection algorithm can significantly reduce the number of active test quantities during a scenario and still be able to identify the true faults.

    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-89943 (URN)
    Konferanse
    10th European Workshop on Advanced Control and Diagnosis, ACD 2012, November 8-9, Copenhagen, Denmark
    Tilgjengelig fra: 2013-03-11 Laget: 2013-03-11 Sist oppdatert: 2019-09-23bibliografisk kontrollert
    4. Flywheel angular velocity model for misfire simulation
    Åpne denne publikasjonen i ny fane eller vindu >>Flywheel angular velocity model for misfire simulation
    2013 (engelsk)Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    A flywheel angular velocity model for misfire and disturbance simulation is presented. Applications of the model are, for example, initial parameter calibration or robustness analysis of misfire detection algorithms. An analytical model of cylinder pressure is used to model cylinder torque and a multi-body model is used to model crankshaft and driveline oscillations. Different types of disturbances, such as cylinder variations, changes in auxiliary load, and flywheel manufacturing errors can be injected in the model. A qualitative validation of the model shows that simulated angular velocity captures the amplitude and oscillatory behavior of real measurements and the effects of different types of disturbances, e.g. misfire and flywheel manufacturing errors.

    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-89944 (URN)
    Tilgjengelig fra: 2013-03-12 Laget: 2013-03-12 Sist oppdatert: 2019-09-23
    5. Analysis and optimization with the Kullback-Leibler divergence for misfire detection using estimated torque
    Åpne denne publikasjonen i ny fane eller vindu >>Analysis and optimization with the Kullback-Leibler divergence for misfire detection using estimated torque
    2013 (engelsk)Rapport (Annet vitenskapelig)
    Abstract [en]

    Engine misfire detection is an important part of the On-Board Diagnostics (OBDII) legislations to reduce exhaust emissions and avoid damage to the catalytic converters. The flywheel angular velocity signal is analyzed, investigating how to use the signal in order to best detect misfires. An algorithm for engine misfire detection is proposed based on the flywheel angular velocity signal. The flywheel signal is used to estimate the torque at the flywheel and a test quantity is designed by weighting and thresholding the samples of estimated torque related to one combustion. During the development process, the Kullback-Leibler divergence is used to analyze the ability to detect a misfire given a test quantity and how the misfire detectability performance varies depending on, e.g., load and speed. The Kullback-Leibler divergence is also used for parameter optimization to maximize the difference between misfire data and fault-free data. Evaluation shows that the proposed misfire detection algorithm is able to have a low probability of false alarms while having a low probability of missed detections.

    sted, utgiver, år, opplag, sider
    Linköping: Linköping University Electronic Press, 2013. s. 36
    Serie
    LiTH-ISY-R, ISSN 1400-3902 ; 3057
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-89946 (URN)LiTH-ISY-R-3057 (ISRN)
    Tilgjengelig fra: 2013-03-12 Laget: 2013-03-12 Sist oppdatert: 2019-09-23bibliografisk kontrollert
  • 87.
    Eriksson, Daniel
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Eriksson, Lars
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Frisk, Erik
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Krysander, Mattias
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Analysis and optimization with the Kullback-Leibler divergence for misfire detection using estimated torque2013Rapport (Annet vitenskapelig)
    Abstract [en]

    Engine misfire detection is an important part of the On-Board Diagnostics (OBDII) legislations to reduce exhaust emissions and avoid damage to the catalytic converters. The flywheel angular velocity signal is analyzed, investigating how to use the signal in order to best detect misfires. An algorithm for engine misfire detection is proposed based on the flywheel angular velocity signal. The flywheel signal is used to estimate the torque at the flywheel and a test quantity is designed by weighting and thresholding the samples of estimated torque related to one combustion. During the development process, the Kullback-Leibler divergence is used to analyze the ability to detect a misfire given a test quantity and how the misfire detectability performance varies depending on, e.g., load and speed. The Kullback-Leibler divergence is also used for parameter optimization to maximize the difference between misfire data and fault-free data. Evaluation shows that the proposed misfire detection algorithm is able to have a low probability of false alarms while having a low probability of missed detections.

  • 88.
    Eriksson, Daniel
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Eriksson, Lars
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Frisk, Erik
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Krysander, Mattias
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Flywheel angular velocity model for misfire and driveline disturbance simulation2013Inngår i: Proceedings of the 7th IFAC Symposium on Advances in Automotive Control, The International Federation of Automatic Control, Elsevier, 2013, Vol. 46, nr 21, s. 570-575Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A flywheel angular velocity model for misfire and disturbance simulation is presented. Applications of the model are, for example, initial parameter calibration and robustness analysis of misfire detection algorithms. An analytical cylinder pressure model is used to model cylinder torque and a multi-body model with torsional flexibilities is used to model crankshaft and driveline oscillations. Misfires, cylinder variations, changes in auxiliary load, and flywheel manufacturing errors can be injected in the model and the resulting speed variations can be simulated. A qualitative validation of the model shows that simulated angular velocity captures the amplitude and oscillatory behavior of measurement data and the effects of different phenomena, such as misfire and flywheel manufacturing errors.

  • 89.
    Eriksson, Daniel
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Eriksson, Lars
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Frisk, Erik
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Krysander, Mattias
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Flywheel angular velocity model for misfire simulation2013Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    A flywheel angular velocity model for misfire and disturbance simulation is presented. Applications of the model are, for example, initial parameter calibration or robustness analysis of misfire detection algorithms. An analytical model of cylinder pressure is used to model cylinder torque and a multi-body model is used to model crankshaft and driveline oscillations. Different types of disturbances, such as cylinder variations, changes in auxiliary load, and flywheel manufacturing errors can be injected in the model. A qualitative validation of the model shows that simulated angular velocity captures the amplitude and oscillatory behavior of real measurements and the effects of different types of disturbances, e.g. misfire and flywheel manufacturing errors.

  • 90.
    Eriksson, Daniel
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Frisk, Erik
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Krysander, Mattias
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    A method for quantitative fault diagnosability analysis of stochastic linear descriptor models2013Inngår i: Automatica, ISSN 0005-1098, E-ISSN 1873-2836, Vol. 49, nr 6, s. 1591-1600Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Analyzing fault diagnosability performance for a given model, before developing a diagnosis algorithm, can be used to answer questions like “How difficult is it to detect a fault fi?” or “How difficult is it to isolate a fault fi from a fault fj?”. The main contributions are the derivation of a measure, distinguishability, and a method for analyzing fault diagnosability performance of discrete-time descriptor models. The method, based on the Kullback–Leibler divergence, utilizes a stochastic characterization of the different fault modes to quantify diagnosability performance. Another contribution is the relation between distinguishability and the fault to noise ratio of residual generators. It is also shown how to design residual generators with maximum fault to noise ratio if the noise is assumed to be i.i.d. Gaussian signals. Finally, the method is applied to a heavy duty diesel engine model to exemplify how to analyze diagnosability performance of non-linear dynamic models.

  • 91.
    Eriksson, Daniel
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Frisk, Erik
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Krysander, Mattias
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    A sequential test selection algorithm for fault isolation2012Inngår i: Proceedings of the 10th European Workshop on Advanced Control and Diagnosis, ACD 2012, Copenhagen, Denmark, 2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A sequential test selection algorithm is proposed which updates the set of active test quantities depending on the present minimal candidates. By sequentially updating the set of active test quantities, computational time and memory usage can be reduced. If test quantities are generated on-line, a sequential test selection algorithm gives information about which test quantities that should be created. The test selection problem is defined as an optimization problem where a set of active test quantities is chosen such that the cost is minimized while the set fulfills a required minimum detectability and isolability performance. A quantitative diagnosability measure, distinguishability, is used to quantify diagnosability performance of test quantities. The proposed test selection algorithm is applied to a DC-circuit where the diagnosis algorithm generates residuals on-line. Experiments show that the sequential test selection algorithm can significantly reduce the number of active test quantities during a scenario and still be able to identify the true faults.

  • 92.
    Eriksson, Daniel
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Krysander, Mattias
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Frisk, Erik
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    Quantitative Fault Diagnosability Performance of Linear Dynamic Descriptor Models2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A theory is developed for quantifying fault detectability and fault isolability properties of time discrete linear dynamic models. Based on the model, a stochastic characterization of system behavior in different fault modes is defined and a general measure, called distinguishability, based on the Kullback-Leibler information, is used to quantify the difference between the modes. An analysis of distinguishability as a function of the number of observations is discussed. This measure is also shown to be closely related to the fault to noise ratios in residual generators. Further, the distinguishability of the model is shown to give upper limits of the fault to noise ratios of residual generators.

  • 93.
    Eriksson, Daniel
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Krysander, Mattias
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Frisk, Erik
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Quantitative Stochastic Fault Diagnosability Analysis2011Inngår i: 2011 50th IEEE Conference on Decision and Control andEuropean Control Conference (CDC-ECC)Orlando, FL, USA, December 12-15, 2011, Institute of Electrical and Electronics Engineers (IEEE), 2011, s. 1563-1569Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A theory is developed for quantifying fault detectability and fault isolability properties of static linear stochastic models. Based on the model, a stochastic characterization of system behavior in different fault modes is defined and a general measure, based on the Kullback-Leibler information, is proposed to quantify the difference between the modes. This measure, called distinguishability, of the model is shown to give sharp upper limits of the fault to noise ratios of residual generators. Finally, a case-study of a diesel engine model shows how the general framework can be applied to a dynamic and nonlinear model.

  • 94.
    Eriksson, Daniel
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Krysander, Mattias
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Frisk, Erik
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Using quantitative diagnosability analysis for optimal sensor placement2012Inngår i: Proceedings of the 8th IFAC Safe Process, Mexico City, Mexico / [ed] Carlos Manuel Astorga-Zaragoza, Arturo Molina Gutierrez and Adriana Aguilera-Gonzalez, Curran Associates, Inc., 2012, s. 940-945Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A good placement of sensors is crucial to get good performance in detecting and isolating faults. Here, the sensor placement problem is cast as a minimal cost optimization problem. Previous works have considered this problem with qualitative detectability and isolability specifications. A key contribution here is that quantified detectability and isolability performance is considered in the optimization formulation. The search space for the posed optimization problem is exponential in size, and to handle complexity a greedy optimization algorithm that compute optimal sensor positions is proposed. Two examples illustrate how the optimal solution depends on the required quantified diagnosability performance and the results are compared to the solutions using a deterministic method.

  • 95.
    Eriksson, Daniel
    et al.
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Sundström, Christofer
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Sequential Residual Generator Selection for Fault Detection2014Inngår i: 2014 EUROPEAN CONTROL CONFERENCE (ECC), IEEE , 2014, s. 932-937Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Structural methods in model-based fault diagnosis applications are simple and efficient tools for finding candidates for residual generation. However, the structural methods do not take model uncertainties and information about fault behavior into consideration. This may result in selecting residual generators with bad performance to be included in the diagnosis system. By using the Kullback-Leibler divergence, the performance of different residual generators can be compared to find the best one. With the ability to quantify diagnostic performance, the design of residual generators can be optimized by, for example, combining several residual generators such that the diagnostic performance is maximized. The proposed method for residual generation selection is applied to a water tank system to show that the achieved residual performance is improved compared to only use a structural method.

  • 96.
    Eriksson, Lars
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    A European Perspective on Collaborative Research in Modeling and Control of Turbocharged Engines2014Inngår i: Journal of the Society of Instrument and Control Engineers, ISSN 0453-4662, Vol. 53, nr 8, s. 716-724Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Modeling and simulation plays an important role in the design of the control systems for advanced power­trains. One clear trend is that turbocharged engines are becoming more common and are also being equipped with more than one boosting device. To systematicaUy handle these advanced turbocharging concepts we need to build more knowledge and this knowledge is encap­sulated in models. Recent results for modeling and control of compres­sors in advanced engines are provided.   In particular the experimental results from a large measurement cam-paign with engine and gas stand hardware an;\ sum­marized as rules of thumb extrapolating manufacturer compressor data. Thereafter, system properties öf V­engines with pa.rallel turbocharging is investigated and used to illustrate applications of the newly developed modeling knowledge. It is used to niodel, simulate and analyzc a compressor instability phenomenon that gives rise to an oscillation. A detection scheme and a con­troller is also developed and it is shown to quell the oscillation. Finally the benefits of academic and industrial collab­oration, that play an important role in the authors lab as well as in many European institutes, are commented upon. A concluding remark is that thc works that are summarized would not have been possible without the cooperation between academy and industry.

  • 97.
    Eriksson, Lars
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    A Real-Time Platform for Spark Advance Control1997Rapport (Annet vitenskapelig)
    Abstract [en]

    With the aim at spark advance control, a method for estimating the peak pressure position (PPP) from the ionization current has previously been developed and off-line validated. To implement the concept on an engine a real-time platform is needed. A hardware platform, that consists of a PC, an electronic engine control unit (ECU), and a synchronization circuit, is described. The platform synchronizes the data acquisition with the engine and the functionality is validated. Also a refined interpretation algorithm for estimating the PPP is described and validated to give a good estimate. The algorithm is suitable for implementation on the described real-time platform.

  • 98.
    Eriksson, Lars
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    An overview of various control benchmarks with a focus on automotive control2019Inngår i: Control Theory and Technology, ISSN 2095-6983, Vol. 17, nr 2, s. 121-130Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    There exists a gap between control theory and control practice, i.e., all control methods suggested by researchers are not implemented in real systems and, on the other hand, many important industrial problems are not studied in the academic research. Benchmark problems can help close this gap and provide many opportunities for members in both the controls theory and application communities. The goal is to survey and give pointers to different general controls and modeling related benchmark problems that can serve as inspiration for future benchmarks and then specifically focus the benchmark coverage on automotive control engineering application. In the paper reflections are given on how different categories of benchmark designers, benchmark solvers and third part users can benefit from providing, solving, and studying benchmark problems. The paper also collects information about several benchmark problems and gives pointers to papers than give more detailed information about different problems that have been presented.

  • 99.
    Eriksson, Lars
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska fakulteten.
    CHEPP – A Chemical Equilibrium Program Package for Matlab2005Inngår i: SAE technical paper series, ISSN 0148-7191, Vol. 4, nr 113, s. 730-741Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A program package, that calculates chemical equilibrium and thermodynamic properties of reactants and products of a combustion reaction between fuel and air, has been developed and validated. The package consists of the following four parts: 1) A program for calculating chemical equilibrium. 2) A database that contains thermochemical information about the molecules, which comes from the GRI-Mech tables. 3) A GUI that allows the user to easily select fuels, fuel/air ratio for the reaction, and combustion products. 4) A set of functions designed to access the thermochemical database and the chemical equilibrium programs. Results are validated against both the NASA equilibrium program (Gordon and McBride, 1994) and the program developed by Olikara and Borman (1975). It is shown that the new method gives results identical to those well recognized Fortran programs.

  • 100.
    Eriksson, Lars
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Development of a Hardware and Software Platform that Constitutes a Step Towards Adaptive Engine Control1998Konferansepaper (Fagfellevurdert)
1234567 51 - 100 of 624
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