Transparency Improvement in Haptic Devices with a Torque Compensator Using Motor Current

Transparency of a haptic interface can be improved by minimizing the effects of inertia and friction through the use of model based compensators. However, the performance with these algorithms is limited due to the estimation errors in the system model and in the velocity and acceleration from quantized encoder data. This paper contributes a new torque compensator based on motor current to improve transparency. The proposed method was tested experimentally in time and frequency domains by means of an excitation motor attached at the user side of the device. The excitation motor enabled evaluation of the algorithms with smooth trajectories and high frequencies, which cannot be generated by user hand. Experimental results showed that the algorithm significantly improves transparency and doubles the transparency bandwidth.

[1]  Guangjun Liu,et al.  On velocity estimation using position measurements , 2002, Proceedings of the 2002 American Control Conference (IEEE Cat. No.CH37301).

[2]  Emilio Jesús Lázaro Sánchez,et al.  Control Algorithms for Haptic Interaction and Modifying the Dynamical Behavior of the Interface , 2005 .

[3]  Vincent Hayward,et al.  Discrete-time adaptive windowing for velocity estimation , 2000, IEEE Trans. Control. Syst. Technol..

[4]  J. Edward Colgate,et al.  Robust impedance shaping telemanipulation , 1993, IEEE Trans. Robotics Autom..

[5]  Melik Dolen,et al.  An enhanced adaptive windowing technique for velocity and acceleration estimation using incremental position encoders , 2010, ICSES 2010 International Conference on Signals and Electronic Circuits.

[6]  Myung Jin Chung,et al.  Adaptive controller of a master–slave system for transparent teleoperation , 1998 .

[7]  Marcia Kilchenman O'Malley,et al.  Human-machine admittance and transparency adaptation in passive user interaction with a haptic interface , 2005, First Joint Eurohaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems. World Haptics Conference.

[8]  M.K. O'Malley,et al.  Transparency of a Phantom premium haptic interface for active and passive human interaction , 2005, Proceedings of the 2005, American Control Conference, 2005..

[9]  Dale A. Lawrence.  Stability and transparency in bilateral teleoperation , 1993, IEEE Trans. Robotics Autom..

[10]  Septimiu E. Salcudean,et al.  Analysis of Control Architectures for Teleoperation Systems with Impedance/Admittance Master and Slave Manipulators , 2001, Int. J. Robotics Res..

[11]  Michael Goldfarb,et al.  Loop shaping for transparency and stability robustness in bilateral telemanipulation , 2004, IEEE Transactions on Robotics and Automation.

[12]  Michael Goldfarb,et al.  Transparency and Stability Robustness in Two-Channel Bilateral Telemanipulation , 2001 .

[13]  Samuel Thomas McJunkin.  Transparency improvement for haptic interfaces , 2007 .

[14]  Lucy Y. Pao,et al.  Friction modeling and compensation for haptic interfaces , 2005, First Joint Eurohaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems. World Haptics Conference.

[15]  E. I. Konukseven,et al.  A hybrid method to estimate velocity and acceleration using low-resolution optical incremental encoders , 2010, ICSES 2010 International Conference on Signals and Electronic Circuits.

[16]  Antonio Frisoli,et al.  Force‐based impedance control of a haptic master system for teleoperation , 2004 .

[17]  Kevin Cleary,et al.  Closed-Loop Force Control for Haptic Simulation of Virtual Environments , 2000 .

[18]  S. P. Chan.  Velocity Estimation for Robot Manipulators Using Neural Network , 1998, J. Intell. Robotic Syst..

[19]  Marcia K. O'Malley,et al.  Disturbance-Observer-Based Force Estimation for Haptic Feedback , 2011 .

[20]  Feri Yusivar,et al.  A new method of motor speed estimation using fuzzy logic algorithm , 1999, IEEE International Electric Machines and Drives Conference. IEMDC'99. Proceedings (Cat. No.99EX272).

[21]  E. Papadopoulos,et al.  Transparency maximization methodology for haptic devices , 2006, IEEE/ASME Transactions on Mechatronics.