Proxy-Based Sliding Mode Control of Compliant Joint Manipulators

The use of traditional position controllers in robotsworking in close proximity to people can lead to risks that result from the unexpected physical human-robot interactions (pHRI). To obtain effective tracking during normal operations, and retain the ability to recover from position errors in a smooth and damped manner, following contacts with external objects/agents, Proxy-based Sliding Mode Control (PSMC) has been proposed. While the efficacy of this controller in fully actuated manipulators has been studied, its use in underactuated systems has not yet been considered. This paper introduces PSMC for a class of underactuated systems. Specifically it considers the control of flexible joint manipulators with passive elastic elements in series with the motors. The Proxy-based Sliding Mode Control is developed to address the stability requirements of this type of dynamic system, while a torque controller to regulate the output torque of the actuation units is designed using Feedback Linearization and Linear Quadratic optimal control approaches. The performance of the proposed scheme is demonstrated in dynamic simulation of an anthropomorphic compliant robot arm.

[1]  Hugh M. Herr,et al.  The effect of series elasticity on actuator power and work output: Implications for robotic and prosthetic joint design , 2006, Robotics Auton. Syst..

[2]  S. Vijayakumar,et al.  Exploiting variable physical damping in rapid movement tasks , 2012, 2012 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM).

[3]  Nikolaos G. Tsagarakis,et al.  A novel actuator with adjustable stiffness (AwAS) , 2010, 2010 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[4]  Nikolaos G. Tsagarakis,et al.  Physical interaction detection and control of compliant manipulators equipped with friction clutches , 2014, 2014 IEEE International Conference on Robotics and Automation (ICRA).

[5]  R. H. Cannon,et al.  Experiments in control of flexible structures with noncolocated sensors and actuators , 1984 .

[6]  P. Tomei.  A simple PD controller for robots with elastic joints , 1991 .

[7]  Alin Albu-Schäffer,et al.  Robots Driven by Compliant Actuators: Optimal Control Under Actuation Constraints , 2013, IEEE Transactions on Robotics.

[8]  Nikolaos G. Tsagarakis,et al.  Decentralized Feedback Design for a Compliant Robot Arm , 2014, 2014 European Modelling Symposium.

[9]  Hideo Fujimoto,et al.  Proxy-based sliding mode control for accurate and safe position control , 2006, Proceedings 2006 IEEE International Conference on Robotics and Automation, 2006. ICRA 2006..

[10]  Antonio Frisoli,et al.  Linear-quadratic-Gaussian torque control: Application to a flexible joint of a rehabilitation exoskeleton , 2010, 2010 IEEE International Conference on Robotics and Automation.

[11]  Hideo Fujimoto,et al.  Proxy-Based Sliding Mode Control: A Safer Extension of PID Position Control , 2010, IEEE Transactions on Robotics.

[12]  Manuel G. Catalano,et al.  Variable impedance actuators: A review , 2013, Robotics Auton. Syst..

[13]  Hamid D. Taghirad,et al.  A SURVEY ON THE CONTROL OF FLEXIBLE JOINT ROBOTS , 2006 .

[14]  Alin Albu-Schäffer,et al.  Requirements for Safe Robots: Measurements, Analysis and New Insights , 2009, Int. J. Robotics Res..

[15]  Pablo González de Santos,et al.  Combining series elastic actuation and magneto-rheological damping for the control of agile locomotion , 2011, Robotics Auton. Syst..

[16]  Bram Vanderborght,et al.  Proxy-based Sliding Mode Control of a Planar Pneumatic Manipulator , 2009, Int. J. Robotics Res..

[17]  Nikolaos G. Tsagarakis,et al.  A compact compliant actuator (CompAct™) with variable physical damping , 2011, 2011 IEEE International Conference on Robotics and Automation.

[18]  Nikolaos G. Tsagarakis,et al.  A compact soft actuator unit for small scale human friendly robots , 2009, 2009 IEEE International Conference on Robotics and Automation.

[19]  Nikolaos G. Tsagarakis,et al.  VSA-CubeBot: A modular variable stiffness platform for multiple degrees of freedom robots , 2011, 2011 IEEE International Conference on Robotics and Automation.

[20]  Antonio Bicchi,et al.  Compliant design for intrinsic safety: general issues and preliminary design , 2001, Proceedings 2001 IEEE/RSJ International Conference on Intelligent Robots and Systems. Expanding the Societal Role of Robotics in the the Next Millennium (Cat. No.01CH37180).

[21]  Nikolaos G. Tsagarakis,et al.  MACCEPA 2.0: compliant actuator used for energy efficient hopping robot Chobino1D , 2011, Auton. Robots.

[22]  N. G. Tsagarakis,et al.  Dynamic modeling and adaptable control of the CompAct™ arm , 2013, 2013 IEEE International Conference on Mechatronics (ICM).

[23]  Alessandro De Luca,et al.  PD control with on-line gravity compensation for robots with elastic joints: Theory and experiments , 2005, Autom..

[24]  Adi Ben-Israel.  A Newton-Raphson method for the solution of systems of equations , 1966 .

[25]  Luis Hernández,et al.  Proxy-based sliding mode control on platform of 3 degree of freedom (3-DOF) , 2013, Adv. Robotics.

[26]  Nikolaos G. Tsagarakis,et al.  Enhanced physical interaction performance for compliant joint manipulators using proxy-based Sliding Mode Control , 2014, 2014 11th International Conference on Informatics in Control, Automation and Robotics (ICINCO).

[27]  Alin Albu-Schäffer,et al.  Energy Shaping Control for a Class of Underactuated Euler-Lagrange Systems , 2012, SyRoCo.

[28]  Joost Geeroms,et al.  Design of a modular add-on compliant actuator to convert an orthosis into an assistive exoskeleton , 2014, 5th IEEE RAS/EMBS International Conference on Biomedical Robotics and Biomechatronics.

[29]  Bram Vanderborght,et al.  Series-parallel elastic actuation (SPEA) with intermittent mechanism for reduced motor torque and increased efficiency , 2013, 2013 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[30]  Bram Vanderborght,et al.  Design and control of a lower limb exoskeleton for robot-assisted gait training , 2009 .

[31]  Romeo Ortega,et al.  Passivity-based Control of Euler-Lagrange Systems , 1998 .

[32]  Nikolaos G. Tsagarakis,et al.  Optimal control for maximizing velocity of the CompAct™ compliant actuator , 2013, 2013 IEEE International Conference on Robotics and Automation.

[33]  Nikolaos G. Tsagarakis,et al.  Real-time damping estimation for variable impedance actuators , 2014, 2014 IEEE International Conference on Robotics and Automation (ICRA).

[34]  R. Ortega.  Passivity-based control of Euler-Lagrange systems : mechanical, electrical and electromechanical applications , 1998 .

[35]  Nikolaos G. Tsagarakis,et al.  CompAct Arm™: a Compliant Manipulator with Intrinsic Variable Physical Damping , 2012, Robotics: Science and Systems.

[36]  Nikolaos G. Tsagarakis,et al.  Link position control of a compliant actuator with unknown transmission friction torque , 2013, 2013 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[37]  Nikolaos G. Tsagarakis,et al.  On the stiffness design of intrinsic compliant manipulators , 2013, 2013 IEEE/ASME International Conference on Advanced Intelligent Mechatronics.

[38]  Nikolaos G. Tsagarakis,et al.  Model-free force tracking control of piezoelectric actuators: Application to variable damping actuator , 2014, 2014 IEEE International Conference on Robotics and Automation (ICRA).