| 1. |
- Axelsson, Patrik, 1985-, et al.
(författare)
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Extended Kalman Filter Applied to Industrial Manipulators
- 2010
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Ingår i: Proceedings of Reglermöte 2010.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper summarizes previous work on tool position estimation on industrial manipulators, and emphasize the problems that must be taken care of in order to get a satisfied result. The acceleration of the robot tool, measured by an accelerometer, together with measurements of motor angles are used. The states are estimated with an extended Kalman filter. A method for tuning the covariance matrices for the noise, used in the observer, is suggested. The work has been focused on a robot with two degrees of freedom.
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| 2. |
- Carvalho Bittencourt, André, et al.
(författare)
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An Extended Friction Model to capture Load and Temperature effects in Robot Joints
- 2010
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Ingår i: Proceedings of the 2010 IEEE/RSJ International Conference on Intelligent Robots and Systems. - Linköping : Linköping University Electronic Press. - 9781424466740 ; , s. 6161-6167
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Konferensbidrag (refereegranskat)abstract
- Friction is the result of complex interactions between contacting surfaces in a nanoscale perspective. Depending on the application, the different models available are more or less suitable. Available static friction models are typically considered to be dependent only on relative speed of interacting surfaces. However, it is known that friction can be affected by other factors than speed. In this paper, static friction in robot joints is studied with respect to changes in joint angle, load torque and temperature. The effects of these variables are analyzed by means of experiments on a standard industrial robot. Justified by their significance, load torque and temperature are included in an extended static friction model. The proposed model is validated in a wide operating range, reducing the average error a factor of 6 when compared to a standard static friction model.
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| 3. |
- Enqvist, Martin, 1976-, et al.
(författare)
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The CDIO Initiative from an Automatic Control Project Course Perspective
- 2005
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Ingår i: Proceedings of the 16th IFAC World Congress. - 9783902661753 ; , s. 2283-2283
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Konferensbidrag (refereegranskat)abstract
- The CDIO (Conceive Design Implement Operate) Initiative is explained, and some of the results at the Applied Physics and Electrical Engineering program at Linköping University, Sweden, are presented. A project course in Automatic Control is used as an example. The projects within the course are carried out using the LIPS (Linköping interactive project steering) model. An example of a project, the golf playing industrial robot, and the results from this project are also covered.
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| 4. |
- Enqvist, Martin, 1976-, et al.
(författare)
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The CDIO Initiative from an Automatic Control Project Course Perspective
- 2004
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The CDIO (Conceive Design Implement Operate) Initiative is explained, and some of the results at the Applied Physics and Electrical Engineering program at Linköping University, Sweden, are presented. A project course in Automatic Control is used as an example. The projects within the course are carried out using the LIPS (Linköping interactive project steering) model. An example of a project, the golf playing industrial robot, and the results from this project are also covered.
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| 5. |
- Gunnar, Johan, et al.
(författare)
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Nonlinear Grey-box Identification of Linear Actuators Containing Hysteresis
- 2006
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Ingår i: Proceedings of the 2006 IEEE International Conference on Robotics and Automation. - Linköping : Linköping University Electronic Press. - 0780395050 ; , s. 1818-1823
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Konferensbidrag (refereegranskat)abstract
- A new identification procedure for a linear actuator used in parallel kinematic manipulators has been developed. The actuator dynamics contain both hysteresis and backlash resulting in a highly nonlinear system. The results in this paper show that not only can a nonlinear model of the system be successfully identified from measurement data, but the model is also compact enough to be an ideal candidate for inclusion in a high-performance robot control system.
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| 6. |
- Moberg, Stig, 1962-, et al.
(författare)
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Modeling and Parameter Estimation of Robot Manipulators Using Extended Flexible Joint Models
- 2014
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Ingår i: Journal of Dynamic Systems Measurement, and Control. - : ASME International. - 0022-0434 .- 1528-9028. ; 136:3, s. 031005-
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Tidskriftsartikel (refereegranskat)abstract
- This paper considers the problem of dynamic modeling and identification of robot manipulators with respect to their elasticities. The so-called flexible joint model, modeling only the torsional gearbox elasticity, is shown to be insufficient for modeling a modern industrial manipulator accurately. Another lumped parameter model, called the extended flexible joint model, is therefore used to improve the model accuracy. In this model, nonactuated joints are added to model the elasticity of the links and bearings. The unknown elasticity parameters are estimated using a frequency-domain gray-box identification method. The conclusion is that the obtained model describes the movements of the motors and the tool mounted on the robot with significantly higher accuracy than the flexible joint model. Similar elasticity model parameters are obtained when using two different output variables for the identification, the motor position and the tool acceleration.
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| 7. |
- Norrlöf, Mikael, et al.
(författare)
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Experimental Comparison of Observers for Tool Position Estimation of Industrial Robots
- 2009
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Ingår i: Proceedings of the 48th IEEE Conference on Decision and Control. - Linköping : Linköping University Electronic Press. - 9781424438723 - 9781424438716 ; , s. 8065-8070
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Konferensbidrag (refereegranskat)abstract
- This paper investigates methods for tool position estimation of industrial robots. It is assumed that the motor angular position and the tool acceleration are measured. The considered observers are different versions of the extended Kalman filter as well as a deterministic observer. A method for tuning the observers is suggested and the robustness of the methods is investigated. The observers are evaluated experimentally on a commercial industrial robot.
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| 8. |
- Wernholt, Erik, et al.
(författare)
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Analysis of Methods for Multivariable Frequency Response Function Estimation in Closed Loop
- 2007
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Ingår i: Proceedings of the 46th IEEE Conference on Decision and Control. - Linköping : Linköping University Electronic Press. - 9781424414970 - 9781424414987 ; , s. 4881-4888
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Konferensbidrag (refereegranskat)abstract
- Estimation methods for the multivariable frequency response function are analyzed, both in open and closed loop. Expressions for the bias and covariance are derived and the usefulness of these expressions is illustrated in simulations of an industrial robot where the different estimators are compared. The choice of estimator depends on the signal-to- noise ratio as well as the measurement setup and a bias-variance trade-off.
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| 9. |
- Wernholt, Erik, 1975-, et al.
(författare)
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Detection and Estimation of Nonlinear Distortions in Industrial Robots
- 2006
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Ingår i: Proceedings of the 23rd IEEE Instumentation and Measurement Technology Conference. - Linköping : Linköping University Electronic Press. - 0780393600 - 0780393597 ; , s. 1913-1918
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Konferensbidrag (refereegranskat)abstract
- System identification in robotics often involves the estimation of linear models characterizing the behavior in certain operating points. In this paper, a method for the detection and estimation of nonlinear distortions in an estimated frequency response function (FRF) has successfully been applied to experimental data from an industrial robot. The results show that nonlinear distortions areindeed present and cause larger variability in the FRF than the measurement noise contributions.
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| 10. |
- Wernholt, Erik, et al.
(författare)
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Estimation of nonlinear effects in frequency-domain identification of industrial robots
- 2008
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - : IEEE. - 0018-9456 .- 1557-9662. ; 57:4, s. 856-863
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Tidskriftsartikel (refereegranskat)abstract
- A method for the detection and estimation of nonlinear distortions when identifying multivariable frequency response functions (FRF) is considered. The method is successfully applied to experimental data, which were collected in closed loop, from an industrial robot. The results show that nonlinear distortions are indeed present and cause larger variability in the FRF than the measurement-noise contributions.
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