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Norrlöf, Mikael
Alternative names
Publications (10 of 141) Show all publications
Hedberg, E., Norrlöf, M., Moberg, S. & Gunnarsson, S. (2018). Comparing Feedback Linearization and Jacobian Linearization for LQ Control of an Industrial Manipulator. In: Proccedings of the 12TH IFAC SYMPOSIUM ON ROBOT CONTROL: . Paper presented at 12TH IFAC SYMPOSIUM ON ROBOT CONTROL.
Open this publication in new window or tab >>Comparing Feedback Linearization and Jacobian Linearization for LQ Control of an Industrial Manipulator
2018 (English)In: Proccedings of the 12TH IFAC SYMPOSIUM ON ROBOT CONTROL, 2018Conference paper, Published paper (Refereed)
Abstract [en]

Feedback linearization is compared to Jacobian linearization for LQ control of atwo-link industrial manipulator. A method for obtaining equivalent nominal performance forboth control designs is introduced. An experimentally verified benchmark model with industrialrelevance is used for comparing the designs. Results do not show any conclusive advantages ofFeedback linearization.

National Category
Control Engineering
Identifiers
urn:nbn:se:liu:diva-151588 (URN)
Conference
12TH IFAC SYMPOSIUM ON ROBOT CONTROL
Available from: 2018-09-25 Created: 2018-09-25 Last updated: 2018-10-19
Eriksson, L. & Norrlöf, M. (2015). Improved Drive Cycle Following with an ILC Supported Driver Model. In: 4th IFAC Workshop on Engine and Powertrain Control, Simulation and Modeling ECOSM’15: . Paper presented at 4th IFAC Workshop on Engine and Powertrain Control, Simulation and Modeling E-COSM 2015 Columbus, Ohio, USA, 23-26 August 2015 (pp. 347-353). The International Federation of Automatic Control (IFAC), 48
Open this publication in new window or tab >>Improved Drive Cycle Following with an ILC Supported Driver Model
2015 (English)In: 4th IFAC Workshop on Engine and Powertrain Control, Simulation and Modeling ECOSM’15, The International Federation of Automatic Control (IFAC) , 2015, Vol. 48, p. 347-353Conference paper, Published paper (Refereed)
Abstract [en]

Drive cycle following is important for concept comparisons when evaluating vehicle concepts, but it can be time consuming to develop good driver models that can achieve accurate following of a specific velocity profile. Here, a new approach is proposed where a simple driver model based on a PID controller is extended with an Iterative Learning Control (ILC) algorithm. Simulation results using a nonlinear vehicle and control system model show that it is possible to achieve very good cycle following in a few iterations with little tuning effort. It is also possible to utilize the repetitive behavior in the drive cycle to accelerate the convergence of the ILC algorithm even further.

Place, publisher, year, edition, pages
The International Federation of Automatic Control (IFAC), 2015
Series
IFAC-PapersOnLine, ISSN 2405-8963 ; 15
National Category
Control Engineering
Identifiers
urn:nbn:se:liu:diva-137725 (URN)10.1016/j.ifacol.2015.10.050 (DOI)
Conference
4th IFAC Workshop on Engine and Powertrain Control, Simulation and Modeling E-COSM 2015 Columbus, Ohio, USA, 23-26 August 2015
Available from: 2017-06-02 Created: 2017-06-02 Last updated: 2018-01-30Bibliographically approved
Carvalho Bittencourt, A., Saarinen, K., Sander Tavallaey, S., Gunnarsson, S. & Norrlöf, M. (2014). A data-driven approach to diagnostics of repetitive processes in the distribution domain: Applications to gearbox diagnosticsin industrial robots and rotating machines. Mechatronics (Oxford), 24(8), 1032-1041
Open this publication in new window or tab >>A data-driven approach to diagnostics of repetitive processes in the distribution domain: Applications to gearbox diagnosticsin industrial robots and rotating machines
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2014 (English)In: Mechatronics (Oxford), ISSN 0957-4158, E-ISSN 1873-4006, Vol. 24, no 8, p. 1032-1041Article in journal (Refereed) Published
Abstract [en]

This paper presents a data-driven approach to diagnostics of systems that operate in a repetitive manner. Considering that data batches collected from a repetitive operation will be similar unless in the presence of an abnormality, a condition change is inferred by comparing the monitored data against an available nominal batch. The method proposed considers the comparison of data in the distribution domain, which reveals information of the data amplitude. This is achieved with the use of kernel density estimates and the Kullback–Leibler distance. To decrease sensitivity to disturbances while increasing sensitivity to faults, the use of a weighting vector is suggested which is chosen based on a labeled dataset. The framework is simple to implement and can be used without process interruption, in a batch manner. The approach is demonstrated with successful experimental and simulation applications to wear diagnostics in an industrial robot gearbox and for diagnostics of gear faults in a rotating machine.

Place, publisher, year, edition, pages
Elsevier, 2014
National Category
Robotics
Identifiers
urn:nbn:se:liu:diva-109332 (URN)10.1016/j.mechatronics.2014.01.013 (DOI)000347499900014 ()
Funder
VINNOVA
Available from: 2014-08-13 Created: 2014-08-13 Last updated: 2017-12-05Bibliographically approved
Wallen Axehill, J., Dressler, I., Gunnarsson, S., Robertsson, A. & Norrlöf, M. (2014). Estimation-based ILC applied to a parallel kinematic robot. Control Engineering Practice, 33
Open this publication in new window or tab >>Estimation-based ILC applied to a parallel kinematic robot
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2014 (English)In: Control Engineering Practice, ISSN 0967-0661, E-ISSN 1873-6939, Vol. 33Article in journal (Refereed) Published
Abstract [en]

Estimation-based iterative learning control (ILC) is applied to a parallel kinematic manipulator known as the Gantry-Tau parallel robot. The system represents a control problem where measurements of the controlled variables are not available. The main idea is to use estimates of the controlled variables in the ILC algorithm, and in the paper this approach is evaluated experimentally on the Gantry-Tau robot. The experimental results show that an ILC algorithm using estimates of the tool position gives a considerable improvement of the control performance. The tool position estimate is obtained by fusing measurements of the actuator angular positions with measurements of the tool path acceleration using a complementary filter.

Place, publisher, year, edition, pages
Elsevier, 2014
Keywords
Iterative methods; Learning control; Robotic manipulator; Estimation algorithm; Performance evaluation
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-113180 (URN)10.1016/j.conengprac.2014.08.008 (DOI)000345728700001 ()
Note

Funding Agencies|ELLIIT, Excellence Center at Linkoping - Lund in Information Technology; LCCC Linnaeus Center at Lund University; Vinnovas Industry Excellence Center LINK-SIC at Linkoping University

Available from: 2015-01-13 Created: 2015-01-12 Last updated: 2017-12-05
Axelsson, P., Karlsson, R. & Norrlöf, M. (2014). Estimation-based Norm-optimal Iterative Learning Control. Systems & control letters (Print), 73, 76-80
Open this publication in new window or tab >>Estimation-based Norm-optimal Iterative Learning Control
2014 (English)In: Systems & control letters (Print), ISSN 0167-6911, E-ISSN 1872-7956, Vol. 73, p. 76-80Article in journal (Refereed) Published
Abstract [en]

The norm-optimal iterative learning control (ilc) algorithm for linear systems is extended to an estimation-based norm-optimal ilc  algorithm where the controlled variables are not directly available as measurements. A separation lemma is presented, stating that if a stationary Kalman filter is used for linear time-invariant systems then the ilc  design is independent of the dynamics in the Kalman filter. Furthermore, the objective function in the optimisation problem is modified to incorporate the full probability density function of the error. Utilising the Kullback–Leibler divergence leads to an automatic and intuitive way of tuning the ilc  algorithm. Finally, the concept is extended to non-linear state space models using linearisation techniques, where it is assumed that the full state vector is estimated and used in the ilc  algorithm. Stability and convergence properties for the proposed scheme are also derived.

Place, publisher, year, edition, pages
Elsevier, 2014
Keywords
Iterative learning control; Estimation; Filtering; Non-linear systems
National Category
Control Engineering
Identifiers
urn:nbn:se:liu:diva-104791 (URN)10.1016/j.sysconle.2014.08.007 (DOI)000345108000010 ()
Projects
Vinnova Excellence Center LINK-SICExcellence Center at Linköping-Lund in Information Technology, ELLIITSSF project Collaborative Localization
Funder
VINNOVAeLLIIT - The Linköping‐Lund Initiative on IT and Mobile Communications
Available from: 2014-02-26 Created: 2014-02-26 Last updated: 2017-12-05
Axelsson, P., Helmersson, A. & Norrlöf, M. (2014). H∞-Controller Design Methods Applied to One Joint of a Flexible Industrial Manipulator. In: Boje, Edward and Xia, Xiaohua (Ed.), Proceedings of the 19th IFAC World Congress, 2014: . Paper presented at 19th IFAC World Congress, August 24-29, Cape Town, South Africa (pp. 210-216). International Federation of Automatic Control
Open this publication in new window or tab >>H-Controller Design Methods Applied to One Joint of a Flexible Industrial Manipulator
2014 (English)In: Proceedings of the 19th IFAC World Congress, 2014 / [ed] Boje, Edward and Xia, Xiaohua, International Federation of Automatic Control , 2014, p. 210-216Conference paper, Published paper (Refereed)
Abstract [en]

Control of a flexible joint of an industrial manipulator using H design methods is presented. The considered design methods are i) mixed-H design, and ii) H loop shaping design. Two different controller configurations are examined: one uses only the actuator position, while the other uses the actuator position and the acceleration of end-effector. The four resulting controllers are compared to a standard PID controller where only the actuator position is measured. The choices of the weighting functions are discussed in details. For the loop shaping design method, the acceleration measurement is required to improve the performance compared to the PID controller. For the mixed-H method it is enough to have only the actuator position to get an improved performance. Model order reduction of the controllers is briefly discussed, which is important for implementation of the controllers in the robot control system.

Place, publisher, year, edition, pages
International Federation of Automatic Control, 2014
Series
World Congress, ISSN 1474-6670 ; Volume# 19, Part# 1
Keywords
Robotics, Flexible, H-infinity control, Accelerometers
National Category
Control Engineering
Identifiers
urn:nbn:se:liu:diva-104785 (URN)10.3182/20140824-6-ZA-1003.00143 (DOI)978-3-902823-62-5 (ISBN)
Conference
19th IFAC World Congress, August 24-29, Cape Town, South Africa
Projects
Vinnova Excellence Center LINK-SICExcellence Center at Linköping-Lund in Information Technology, ELLIIT
Funder
VinnovaeLLIIT - The Linköping‐Lund Initiative on IT and Mobile Communications
Available from: 2014-02-26 Created: 2014-02-26 Last updated: 2014-10-23Bibliographically approved
Axelsson, P., Pipeleers, G., Helmersson, A. & Norrlöf, M. (2014). H∞ Synthesis Method for Control of Non-linear Flexible Joint Models. In: Boje, Edward and Xia, Xiaohua (Ed.), Proceedings of the 19th IFAC World Congress, 2014: . Paper presented at 19th IFAC World Congress, August 24-29, Cape Town, South Africa (pp. 8372-8377). International Federation of Automatic Control
Open this publication in new window or tab >>H Synthesis Method for Control of Non-linear Flexible Joint Models
2014 (English)In: Proceedings of the 19th IFAC World Congress, 2014 / [ed] Boje, Edward and Xia, Xiaohua, International Federation of Automatic Control , 2014, p. 8372-8377Conference paper, Published paper (Refereed)
Abstract [en]

An H synthesis method for control of a flexible joint, with non-linear spring characteristic, is proposed. The first step of the synthesis method is to extend the joint model with an uncertainty description of the stiffness parameter. In the second step, a non-linear optimisation problem, based on nominal performance and robust stability requirements, has to be solved. Using the Lyapunov shaping paradigm and a change of variables, the non-linear optimisation problem can be rewritten as a convex, yet conservative, LMI problem. The method is motivated by the assumption that the joint operates in a specific stiffness region of the non-linear spring most of the time, hence the performance requirements are only valid in that region. However, the controller must stabilise the system in all stiffness regions. The method is validated in simulations on a non-linear flexible joint model originating from an industrial robot.

Place, publisher, year, edition, pages
International Federation of Automatic Control, 2014
Series
World Congress, ISSN 1474-6670 ; Volume# 19, Part# 1
Keywords
Mechanical systems, Flexible, Robust, H-infinity Control
National Category
Control Engineering
Identifiers
urn:nbn:se:liu:diva-104789 (URN)10.3182/20140824-6-ZA-1003.00142 (DOI)978-3-902823-62-5 (ISBN)
Conference
19th IFAC World Congress, August 24-29, Cape Town, South Africa
Projects
Vinnova Excellence Center LINK-SICExcellence Center at Linköping-Lund in Information Technology, ELLIIT
Funder
VinnovaeLLIIT - The Linköping‐Lund Initiative on IT and Mobile Communications
Available from: 2014-02-26 Created: 2014-02-26 Last updated: 2014-10-23Bibliographically approved
Axelsson, P., Axehill, D., Glad, T. & Norrlöf, M. (2014). Iterative Learning Control - From a Controllability Point of View. In: Proceedings of Reglermöte 2014: . Paper presented at Reglermöte 2014, Linköping, Sweden, 3-4 June, 2014.
Open this publication in new window or tab >>Iterative Learning Control - From a Controllability Point of View
2014 (English)In: Proceedings of Reglermöte 2014, 2014Conference paper, Published paper (Other academic)
National Category
Control Engineering
Identifiers
urn:nbn:se:liu:diva-107146 (URN)
Conference
Reglermöte 2014, Linköping, Sweden, 3-4 June, 2014
Projects
Vinnova Excellence Center LINK-SIC at Linköping University
Funder
Vinnova
Available from: 2014-06-05 Created: 2014-06-05 Last updated: 2016-08-31
Samuelsson, A., Carvalho Bittencourt, A., Saarinen, K., Sander Tavallaey, S., Norrlöf, M., Andersson, H. & Gunnarsson, S. (2014). Simulation based Evaluation of Fault Detection Algorithms: Applications to Wear Diagnosis in Manipulators. In: Proceedings of the 19th IFAC World Congress: . Paper presented at 19th IFAC World Congress, Cape Town, South Africa, August 24-29, 2014.
Open this publication in new window or tab >>Simulation based Evaluation of Fault Detection Algorithms: Applications to Wear Diagnosis in Manipulators
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2014 (English)In: Proceedings of the 19th IFAC World Congress, 2014Conference paper, Published paper (Refereed)
Abstract [en]

Fault detection algorithms (FDAs) process data to generate a test quantity. Test quantities are used to determine presence of a fault in a monitored system, despite disturbances. Because only limited knowledge of the system can be embedded in an FDA, it is important to evaluate it in scenarios relevant in practice. In this paper, simulation based approaches are proposed in an attempt to determine: i) which disturbances affect the output of an FDA the most; ii) how to compare the performance of dierent FDAs; and iii) which combinations of fault change size and disturbances variations are allowed to achieve satisfactory performance. The ideas presented are inspired by the literature of design of experiments, surrogate models, sensitivity analysis and change detection. The approaches are illustrated for the problem of wear diagnosis in manipulators where three FDAs are considered. The application study reveals that disturbances caused by variations in temperature and payload mass error affect the FDAs the most. It is also shown how the size of these disturbances delimit the capacity of an FDA to relate to wear changes. Further comparison of the FDAs reveal which performs "best" in average.

National Category
Control Engineering
Identifiers
urn:nbn:se:liu:diva-109333 (URN)
Conference
19th IFAC World Congress, Cape Town, South Africa, August 24-29, 2014
Funder
Vinnova
Available from: 2014-08-13 Created: 2014-08-13 Last updated: 2014-09-17
Wallén, J., Gunnarsson, S. & Norrlöf, M. (2013). Analysis of boundary effects in iterative learning control. International Journal of Control, 86(3), 410-415
Open this publication in new window or tab >>Analysis of boundary effects in iterative learning control
2013 (English)In: International Journal of Control, ISSN 0020-7179, E-ISSN 1366-5820, Vol. 86, no 3, p. 410-415Article in journal (Refereed) Published
Abstract [en]

Boundary effects in iterative learning control (ILC) algorithms are considered in this article. ILC algorithms involve filtering of input and error signals over finite-time intervals, often using non-causal filters, and it is important that the boundary effects of the filtering operations are handled in an appropriate way. The topic is studied using both a proposed theoretical framework and simulations, and it is shown that the method for handling the boundary effects has impact on the stability and convergence properties of the ILC algorithm.

Place, publisher, year, edition, pages
Taylor & Francis, 2013
Keywords
iterative learning control, boundary effects, implementation, convergence
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-96999 (URN)10.1080/00207179.2012.733889 (DOI)000322306600004 ()
Note

Funding Agencies|Vinnovas Industry Excellence Centre LINK-SIC||strategic research centre ELLIIT at Linkoping University||

Available from: 2013-09-02 Created: 2013-09-02 Last updated: 2017-12-06Bibliographically approved
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