liu.seSearch for publications in DiVA
Change search
Link to record
Permanent link

Direct link
BETA
Nyberg, Peter
Publications (10 of 11) Show all publications
Nyberg, P., Frisk, E. & Nielsen, L. (2017). Driving Cycle Equivalence and Transformation. IEEE Transactions on Vehicular Technology, 66(3), 1963-1974
Open this publication in new window or tab >>Driving Cycle Equivalence and Transformation
2017 (English)In: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 66, no 3, p. 1963-1974Article in journal (Refereed) Published
Abstract [en]

There is a current strong trend where driving cycles are used extensively in vehicle design, especially for calibration and tuning of all powertrain systems for control and diagnosis. In such situations it is essential to capture real driving, and therefore using only a few driving cycles would lead to the risk that a test or a design would be tailored to details in a specific driving cycle. Consequently there are now widespread activities using techniques from statistics, big data and mission modeling to address these issues. For all such methods there is an important final step to calibrate a representative cycle to adhere to fair propulsion requirements on the driven wheels over a cycle. For this a general methodology has been developed, applicable to a wide range of problems involving driving cycle transformations. It is based on a definition of equivalence for driving cycles that loosely speaking defines being similar without being the same. Based on this, a set of algorithms are developed to transform a given driving cycle into an equivalent one, or into a cycle with given equivalence measure. The transformations are effectively handled as a nonlinear program that is solved using general purpose optimization techniques. The proposed method is general and a wide range of constraints can be used.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2017
Keywords
mean tractive force, nonlinear programming, numerical optimization, vehicle design, vehicle propulsion
National Category
Electrical Engineering, Electronic Engineering, Information Engineering Computer Engineering
Identifiers
urn:nbn:se:liu:diva-118104 (URN)10.1109/TVT.2016.2582079 (DOI)000396401400006 ()
Note

Funding agencies|Swedish Hybrid Vehicle Centre; Linnaeus Center CADICS

At the time for thesis presentation publication was in status: Manuscript.

Available from: 2015-05-21 Created: 2015-05-21 Last updated: 2018-01-11Bibliographically approved
Nyberg, P., Frisk, E. & Nielsen, L. (2016). Using Real-World Driving Databases to Generate Driving Cycles with Equivalence Properties. IEEE Transactions on Vehicular Technology, 65(6), 4095-4105
Open this publication in new window or tab >>Using Real-World Driving Databases to Generate Driving Cycles with Equivalence Properties
2016 (English)In: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 65, no 6, p. 4095-4105Article in journal (Refereed) Published
Abstract [en]

Due to the increasing complexity of vehicle design, understanding driver behavior and driving patterns is becoming increasingly more important. Therefore, a large amount of test driving is performed, which together with recordings of normal driving, results in large databases of recorded drives. A fundamental question is how to make best use of these data to devise driving cycles suitable in the development process of vehicles. One way is to generate driving cycles that are representative for the data or for a suitable subset of the data, e.g., regarding geographical location, driving distance, speed range, or many other possible selection variables. Further, to make a fair comparison on two such driving cycles possible, another fundamental requirement is that they should have similar excitation of the vehicle. A key contribution here is an algorithm that combines the two given objectives. A formulation with Markov processes is used to obtain a condensed and effective characterization of the database and to generate candidate driving cycles (CDCs). In addition to that is a method transforming a candidate to an equivalent driving cycle (EqDC) with desired excitation. The method is a general approach but is here based on the components of the mean tractive force (MTF), and this is motivated by a hardware-in-the-loop experiment showing the strong relevance of these MTF components regarding fuel consumption. The result is a new method that combines the generation of driving cycles using real-world driving cycles with the concept of EqDCs.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2016
Keywords
Drive cycle, equivalence measures, equivalent driving cycle (EqDC), mean tractive force (MTF), specific energy, test procedures, vehicle design, vehicle excitation, vehicle propulsion
National Category
Electrical Engineering, Electronic Engineering, Information Engineering Computer Engineering
Identifiers
urn:nbn:se:liu:diva-118101 (URN)10.1109/TVT.2015.2502069 (DOI)000380068500022 ()
Note

Funding agencies|Swedish Hybrid Vehicle Centre; Linnaeus Center CADICS

At the time for thesis presentation publication was in status: Manuscript.

Available from: 2015-05-21 Created: 2015-05-21 Last updated: 2018-01-11Bibliographically approved
Nyberg, P. (2015). Evaluation, Generation, and Transformation of Driving Cycles. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Evaluation, Generation, and Transformation of Driving Cycles
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Driving cycles are important components for evaluation and design of vehicles. They determine the focus of vehicle manufacturers, and indirectly they affect the environmental impact of vehicles since the vehicle control system is usually tuned to one or several driving cycles. Thus, the driving cycle affects the design of the vehicle since cost, fuel consumption, and emissions all depend on the driving cycle used for design. Since the existing standard driving cycles cannot keep up with the changing road infrastructure, the changing vehicle fleet composition, and the growing number of vehicles on the road, which do all cause changes in the driver behavior, the need to get new and representative driving cycles are increasing. A research question is how to generate these new driving cycles so that they are both representative and at the same time have certain equivalence properties, to make fair comparisons of the performance results. Besides generation, another possibility to get more driving cycles is to transform the existing ones into new, different, driving cycles considering equivalence constraints.

With the development of new powertrain concepts the need for evaluation will increase, and an interesting question is how to utilize new developments in dynamometer technology together with new possibilities for connecting equipment. Here a pedal robot is developed to be used in a vehicle mounted in a chassis dynamometer and the setup is used for co-simulation together with a moving base simulator that is connected with a communication line. The results show that the co-simulation can become a realistic driving experience and a viable option for dangerous tests and a complement to tests on a dedicated track or on-road tests, if improvements on the braking and the vehicle feedback to the driver are implemented.

The problem of generating representative driving cycles, with specified excitation at the wheels, is approached with a combined two-step method. AMarkov chain approach is used to generate candidate driving cycles that are then transformed to equivalent driving cycles with respect to the mean tractive force components, which are the used measures. Using an optimization methodology the transformation of driving cycles is formulated as a nonlinear program with constraints and a cost function to minimize. The nonlinear program formulation can handle a wide range of constraints, e.g., the mean tractive force components, different power measures, or available energy for recuperation, and using the vehicle jerk as cost function gives good drivability.

In conclusion, methods for driving cycle design have been proposed where new driving cycles can either be generated from databases, or given driving cycles can be transformed to fulfill certain equivalence constraints, approaching the important problem of similar but not the same. The combination of these approaches yields a stochastic and general method to generate driving cycles with equivalence properties that can be used at several instances during the product development process of vehicles. Thus, a powerful and effective engineering tool has been developed.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2015. p. 17
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1669
National Category
Electrical Engineering, Electronic Engineering, Information Engineering Computer Engineering
Identifiers
urn:nbn:se:liu:diva-117549 (URN)10.3384/diss.diva-117549 (DOI)978-91-7519-065-5 (ISBN)
Public defence
2015-06-10, Visionen, Hus B, Campus Valla, Linköping, 10:15 (English)
Opponent
Supervisors
Available from: 2015-05-21 Created: 2015-05-04 Last updated: 2018-01-11Bibliographically approved
Nyberg, P., Frisk, E. & Nielsen, L. (2014). Generation of Equivalent Driving Cycles Using Markov Chains and Mean Tractive Force Components. In: Proceedings of the 19th World Congress, The International Federation of Automatic Control: . Paper presented at The 19th World Congress, The International Federation of Automatic Control, Cape Town, South Africa. August 24-29, 2014 (pp. 8787-8792). Elsevier, 47(3)
Open this publication in new window or tab >>Generation of Equivalent Driving Cycles Using Markov Chains and Mean Tractive Force Components
2014 (English)In: Proceedings of the 19th World Congress, The International Federation of Automatic Control, Elsevier, 2014, Vol. 47, no 3, p. 8787-8792Conference paper, Published paper (Refereed)
Abstract [en]

In the automotive industry driving cycles have been used to evaluate vehicles in different perspectives. If a vehicle manufacturer focuses only on a fixed driving cycle there is a risk that controllers of the vehicle are optimized for a certain driving cycle and hence are sub-optimal solutions to real-world driving. To deal with this issue, it is beneficial to have a method for generating more driving cycles that in some sense are equivalent but not identical. The idea here is that these generated driving cycles have the same vehicle excitation in the mean tractive force, MTF. Using the individual force components of the MTF in the generation of driving cycles with Markov chains makes it possible to generate equivalent driving cycles that have the same vehicle excitation from real-world driving data. This is motivated since the fuel consumption estimation is more accurate when the MTF components are considered. The result is a new method that combines the generation of driving cycles using real-world driving cycles with the concept of equivalent driving cycles, and the results are promising.

Place, publisher, year, edition, pages
Elsevier, 2014
Series
IFAC Publications / IFAC Proceedings series, ISSN 1474-6670 ; Vol. 47, Issue 3
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-137778 (URN)10.3182/20140824-6-ZA-1003.02239 (DOI)
Conference
The 19th World Congress, The International Federation of Automatic Control, Cape Town, South Africa. August 24-29, 2014
Available from: 2017-05-29 Created: 2017-05-29 Last updated: 2017-06-01Bibliographically approved
Nilsson, T., Nyberg, P., Sundström, C., Frisk, E. & Krysander, M. (2014). Robust Driving Pattern Detection and Identification with a Wheel Loader Application. International journal of vehicle systems modelling and testing, 9(1), 56-76
Open this publication in new window or tab >>Robust Driving Pattern Detection and Identification with a Wheel Loader Application
Show others...
2014 (English)In: International journal of vehicle systems modelling and testing, ISSN 1745-6436, Vol. 9, no 1, p. 56-76Article in journal (Refereed) Published
Abstract [en]

Information about wheel loader usage can be used in several ways to optimize customer adaption. First, optimizing the configuration and component sizing of a wheel loader to customer needs can lead to a significant improvement in e.g. fuel efficiency and cost. Second, relevant driving cycles to be used in the development of wheel loaders can be extracted from usage data. Third, on-line usage identification opens up for the possibility of implementing advanced look-ahead control strategies for wheel loader operation. The main objective here is to develop an on-line algorithm that automatically, using production sensors only, can extract information about the usage of a machine. Two main challenges are that sensors are not located with respect to this task and that significant usage disturbances typically occur during operation. The proposed method is based on a combination of several individually simple techniques using signal processing, state automaton techniques, and parameter estimation algorithms. The approach is found to berobust when evaluated on measured data of wheel loaders loading gravel and shot rock.

Place, publisher, year, edition, pages
InderScience Publishers, 2014
Keywords
Driving cycle; Driving cycle identification; Driving pattern; Pattern identification; Robust detection; State automaton; Usage classification; Usage detection; Wheel loader
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-92222 (URN)10.1504/IJVSMT.2014.059156 (DOI)2-s2.0-84893958574 (Scopus ID)
Available from: 2013-05-08 Created: 2013-05-08 Last updated: 2019-09-23Bibliographically approved
Öberg, P., Nyberg, P. & Nielsen, L. (2013). A New Chassis Dynamometer Laboratory for Vehicle Research. SAE International Journal of Passenger Cars - Electronic and Electrical Systems, 6(1), 152-161
Open this publication in new window or tab >>A New Chassis Dynamometer Laboratory for Vehicle Research
2013 (English)In: SAE International Journal of Passenger Cars - Electronic and Electrical Systems, ISSN 1946-4614, E-ISSN 1946-4622, Vol. 6, no 1, p. 152-161Article in journal (Refereed) Published
Abstract [en]

In recent years the need for testing, calibration and certification of automotive components and powertrains have increased, partly due to the development of new hybrid concepts. At the same time, the development within electrical drives enables more versatile chassis dynamometer setups with better accuracy at a reduced cost. We are developing a new chassis dynamometer laboratory for vehicle research, aiming at extending a recently commercially available dynamometer, building a new laboratory around it, and applying the resulting facility to some new challenging vehicle research problems. The projects are enabled on one hand by collaboration with the dynamometer manufacturer, and on the other hand on collaboration with automotive industry allowing access to relevant internal information and equipment. The test modes of the chassis dynamometer are under development in a joint collaboration with the manufacturer. The laboratory has been operational since September 2011 and has already been used for NVH-analysis for a tire pressure indication application, chassis dynamometer road force co-simulation with a moving base simulator, co-surge modeling and control for a 6-cylinder bi-turbo engine, and traditional engine mapping. We are also looking at projects with focus on look-ahead control, as well as clutch and transmission modeling and control, and driving cycle related research.

National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-92212 (URN)10.4271/2013-01-0402 (DOI)
Available from: 2013-05-08 Created: 2013-05-08 Last updated: 2017-12-06Bibliographically approved
Nyberg, P., Frisk, E. & Nielsen, L. (2013). Driving Cycle Adaption and Design Based on Mean Tractive Force. In: Proceedings of the 7th IFAC Symposium on Advances in Automotive Control, The International Federation of Automatic Contro: . Paper presented at 7th IFAC Symposium on Advances in Automotive Control, The International Federation of Automatic Control, September 4-7, 2013. Tokyo, Japan (pp. 689-694). Elsevier, 46(21)
Open this publication in new window or tab >>Driving Cycle Adaption and Design Based on Mean Tractive Force
2013 (English)In: Proceedings of the 7th IFAC Symposium on Advances in Automotive Control, The International Federation of Automatic Contro, Elsevier, 2013, Vol. 46, no 21, p. 689-694Conference paper, Published paper (Refereed)
Abstract [en]

Driving cycles are used for certification, for comparison of vehicles, and to an increasing extent as an engineering tool in vehicle design. A situation with only a few fixed driving cycles to use would then lead to the risk that a test or design would be tailored to details in the driving cycle instead of being representative. Due to this, and due to the increased use in the development process, there is now a strong need for methods to achieve representative driving cycles that in a wide sense are similar but not the same. To approach this problem area, we define equivalence between driving cycles based on mean tractive force, and develop algorithms and methods for equivalence-modification and equivalence-transformation of driving cycles. There are a number of applications for these methods but one example that is demonstrated is to transform the well-known FTP75 into an equivalent NEDC, and the other way around, to transform the NEDC into an equivalent FTP75.

Place, publisher, year, edition, pages
Elsevier, 2013
Series
IFAC Publications / IFAC Proceedings series, ISSN 1474-6670 ; Vol. 46, Issue 21
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-137783 (URN)10.3182/20130904-4-JP-2042.00113 (DOI)
Conference
7th IFAC Symposium on Advances in Automotive Control, The International Federation of Automatic Control, September 4-7, 2013. Tokyo, Japan
Available from: 2017-05-29 Created: 2017-05-29 Last updated: 2017-06-01Bibliographically approved
Nyberg, P. (2013). Evaluation, Transformation, and Extraction of Driving Cycles and Vehicle Operations. (Licentiate dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Evaluation, Transformation, and Extraction of Driving Cycles and Vehicle Operations
2013 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

A driving cycle is a representation of how vehicles are driven and  is usually represented by a set of data points of vehicle speed  versus time.  Driving cycles have been used to evaluate vehicles for  a long time. A traditional usage of driving cycles have been in  certification test procedures where the exhaust gas emissions from  the vehicles need to comply with legislation. Driving cycles are now  also used in product development for example to size components or  to evaluate different technologies.  Driving cycles can be just a  repetition of measured data, be synthetically designed from  engineering standpoints, be a statistically equivalent  transformation of either of the two previous, or be obtained as an  inverse problem e.g. obtaining driving/operation patterns.  New  methods that generate driving cycles and extract typical behavior  from large amounts of operational data have recently been proposed.  Other methods can be used for comparison of driving cycles, or to  get realistic operations from measured data. 

This work addresses evaluation, transformation and extraction of  driving cycles and vehicle operations.  To be able to test a vehicle  in a controlled environment, a chassis dynamometer is an  option. When the vehicle is mounted, the chassis dynamometer  simulates the road forces that the vehicle would experience if it  would be driven on a real road. A moving base simulator is a  well-established technique to evaluate driver perception of e.g. the  powertrain in a vehicle, and by connecting these two simulators the  fidelity can be enhanced in the moving base simulator and at the  same time the mounted vehicle in the chassis dynamometer is  experiencing more realistic loads. This is due to the driver's  perception in the moving base simulator is close to reality. 

If only a driving cycle is considered in the optimization of a  controller there is a risk that the controllers of vehicles are  tailored to perform well in that specific driving cycle and not  during real-world driving. To avoid the sub-optimization issues, the  operating regions of the engine need to be excited differently. This  can be attained by using a novel algorithm, which is proposed in  this thesis, that alters the driving cycle while maintaining that  the driving cycle tests vehicles in a similar way. This is achieved  by keeping the mean tractive force constant during the process. 

From a manufacturers standpoint it is vital to understand how your  vehicles are being used by the customers. Knowledge about the usage  can be used for design of driving cycles, component sizing and  configuration, during the product development process, and in  control algorithms.  To get a clearer picture of the usage of wheel  loaders, a novel algorithm that automatically, using existing  sensors only, extracts information of the customers usage, is  suggested. The approach is found to be robust when evaluated on  measured data from wheel loaders loading gravel and shot rock.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2013. p. 103
Series
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 1596
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-92180 (URN)LIU-TEK-LIC-2013:30 (Local ID)978-91-7519-597-1 (ISBN)LIU-TEK-LIC-2013:30 (Archive number)LIU-TEK-LIC-2013:30 (OAI)
Presentation
2013-05-30, Visionen, Hus B, Campus Valla, Linköpings universitet, Linköping, 10:15 (Swedish)
Opponent
Supervisors
Available from: 2013-05-08 Created: 2013-05-08 Last updated: 2013-05-08Bibliographically approved
Andersson, A., Nyberg, P., Sehammar, H. & Öberg, P. (2013). Vehicle Powertrain Test Bench Co-Simulation with a Moving Base Simulator Using a Pedal Robot. SAE International Journal of Passenger Cars - Electronic and Electrical Systems, 6(1), 169-179
Open this publication in new window or tab >>Vehicle Powertrain Test Bench Co-Simulation with a Moving Base Simulator Using a Pedal Robot
2013 (English)In: SAE International Journal of Passenger Cars - Electronic and Electrical Systems, ISSN 1946-4614, E-ISSN 1946-4622, Vol. 6, no 1, p. 169-179Article in journal (Refereed) Published
Abstract [en]

To evaluate driver perception of a vehicle powertrain a moving base simulator is a well-established technique. We are connecting the moving base simulator Sim III, at the Swedish National Road and Transport Research Institute with a newly built chassis dynamometer at Vehicular Systems, Linköping University. The purpose of the effort is to enhance fidelity of moving base simulators by letting drivers experience an actual powertrain. At the same time technicians are given a new tool for evaluating powertrain solutions in a controlled environment. As a first step the vehicle model from the chassis dynamometer system has been implemented in Sim III. Interfacing software was developed and an optical fiber covering the physical distance of 500 m between the facilities is used to connect the systems. Further, a pedal robot has been developed that uses two linear actuators pressing the accelerator and brake pedals. The pedal robot uses feedback loops on accelerator position or brake cylinder pressure and is controlled via an UDP interface. Results from running the complete setup showed expected functionality and we are successful in performing a driving mission based on real road topography data. Vehicle acceleration and general driving feel was perceived as realistic by the test subjects while braking still needs improvements. The pedal robot construction enables use of a large set of cars available on the market and except for mounting the brake pressure sensor the time to switch vehicle is approximately 30 minutes.

National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-92215 (URN)10.4271/2013-01-0410 (DOI)
Available from: 2013-05-08 Created: 2013-05-08 Last updated: 2019-04-28Bibliographically approved
Nyberg, P. & Fröberg, A. (2012). Estimation of fuel equivalance factor from a wheel loaders driving cycle. In: : . Paper presented at International Conference on Advanced Vehicle Technologies and Integration (VTI2012), 16-19 July, 2012.
Open this publication in new window or tab >>Estimation of fuel equivalance factor from a wheel loaders driving cycle
2012 (English)Conference paper, Published paper (Refereed)
Abstract [en]

For the case with repetitive driving cycles for a wheel loader the driving cycle parameters affects on the optimal control of the wheel loader is studied. It is clearly seen that average efficiency is not enough and also that incorporating driving cycle parameters such as average power, maximum power and amount of recuperative energy will lead to a better estimate of the fuel equivalence factor W.

Keywords
Powertrain, Vehicle propulsion
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-138087 (URN)
Conference
International Conference on Advanced Vehicle Technologies and Integration (VTI2012), 16-19 July, 2012
Available from: 2017-06-08 Created: 2017-06-08 Last updated: 2017-06-16Bibliographically approved
Organisations

Search in DiVA

Show all publications