Extended Model-Based Feedforward Compensation in ℒ1 Adaptive Control for Mechanical Manipulators: Design and Experiments

This paper deals with a new control scheme for Parallel Kinematic Manipulators (PKMs) based on the L1 adaptive control theory. The original L1 adaptive controller is extended by including an adaptive loop based on the dynamics of the PKM. The additional model-based term is in charge of the compensation of the modeled nonlinear dynamics in the aim of improving the tracking performance. Moreover, the proposed controller is enhanced to reduce the internal forces, which may appear in the case of Redundantly Actuated PKMs (RA-PKMs). The generated control inputs are first regulated through a projection mechanism that reduces the antagonistic internal forces, before being applied to the manipulator. To validate the proposed controller and to show its effectiveness, real-time experiments are conducted on a new four degrees-of-freedom (4-DOFs) RA-PKM developed in our laboratory.

[1]  Chengyu Cao,et al.  Design and Analysis of a Novel L1 Adaptive Controller, Part II: Guaranteed Transient Performance , 2006, 2006 American Control Conference.

[2]  P. Olver.  Nonlinear Systems , 2013 .

[3]  François Pierrot,et al.  A novel RISE-based adaptive feedforward controller for redundantly actuated parallel manipulators , 2014, 2014 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[4]  Sébastien Krut,et al.  A novel (3T-2R) parallel mechanism with large operational workspace and rotational capability , 2014, 2014 IEEE International Conference on Robotics and Automation (ICRA).

[5]  Mark W. Spong,et al.  Adaptive motion control of rigid robots: a tutorial , 1988, Proceedings of the 27th IEEE Conference on Decision and Control.

[6]  B. R. Markiewicz,et al.  Analysis of the computed torque drive method and comparison with conventional position servo for a computer-controlled manipulator , 1973 .

[7]  Masayoshi Tomizuka,et al.  An adaptive control scheme for mechanical manipulators. Compensation of nonlinearity and decoupling control , 1986 .

[8]  Steven Dubowsky,et al.  The application of model-referenced adaptive control to robotic manipulators , 1979 .

[9]  Chengyu Cao,et al.  Design and Analysis of a Novel L1 Adaptive Controller, Part I: Control Signal and Asymptotic Stability , 2006, 2006 American Control Conference.

[10]  Lakmal Seneviratne,et al.  Adaptive Control Of Robot Manipulators , 1992, Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems.

[11]  Samah Aref Shayya,et al.  Towards Rapid and Precise Parallel Kinematic Machines , 2015 .

[12]  Guilherme Sartori Natal,et al.  Dual-Space Control of Extremely Fast Parallel Manipulators: Payload Changes and the 100G Experiment , 2015, IEEE Transactions on Control Systems Technology.

[13]  François Pierrot,et al.  A new extension of desired compensation adaptive control and its real-time application to redundantly actuated PKMs , 2014, 2014 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[14]  Marc Gouttefarde,et al.  Towards 100G with PKM. Is actuation redundancy a good solution for pick-and-place? , 2010, 2010 IEEE International Conference on Robotics and Automation.

[15]  Naira Hovakimyan,et al.  Marginal Stability in ℒ1-Adaptive Control of Manipulators , 2013 .

[16]  S. Cong,et al.  Nonlinear adaptive task space control for a 2-DOF redundantly actuated parallel manipulator , 2009 .

[17]  S. Shankar Sastry,et al.  Adaptive Control of Mechanical Manipulators , 1987, Proceedings. 1986 IEEE International Conference on Robotics and Automation.

[18]  François Pierrot,et al.  ℒ1 adaptive control of parallel kinematic manipulators: Design and real-time experiments , 2015, 2015 IEEE International Conference on Robotics and Automation (ICRA).

[19]  Roberto Horowitz,et al.  Stability and Robustness Analysis of a Class of Adaptive Controllers for Robotic Manipulators , 1990, Int. J. Robotics Res..

[20]  Naira Hovakimyan,et al.  L1 Adaptive Control Theory - Guaranteed Robustness with Fast Adaptation , 2010, Advances in design and control.

[21]  Andreas Müller,et al.  A projection method for the elimination of contradicting control forces in redundantly actuated PKM , 2011, 2011 IEEE International Conference on Robotics and Automation.

[22]  Romeo Ortega,et al.  Adaptive motion control of rigid robots: a tutorial , 1988, Proceedings of the 27th IEEE Conference on Decision and Control.