Input-dependent stability of joint torque control of tendon-driven robot hands

The input-dependent stability observed during torque control experiments using the first joint of the Darmstadt-HAND is discussed. Friction and compliance existing in tendon-sheath drive systems introduce a hysteresis nonlinearity between the joint torque output and the actuator displacement. Although this transmission characteristic is close to the well-known backlash behavior of the gears situated between a motor and a load shift, this hysteresis loop exhibits input-dependent characteristics in the backlash region of the transmission system, with springlike behavior within a portion of the backlash region. Experiments confirmed that there is a close relationship between the input-dependent backlash characteristics and the input-dependent stability. Based on these experiments, the authors describe the transmission characteristic using a simple model and explore the system stability using sinusoidal-input-describing-functions (SIDF). A nondimensional stability-criterion-map that successfully predicts the experimental results is presented. >

[1]  Imin Kao,et al.  Computing and controlling compliance of a robotic hand , 1989, IEEE Trans. Robotics Autom..

[2]  Matthew T. Mason,et al.  Robot Hands and the Mechanics of Manipulation , 1985 .

[3]  K. Youcef-Toumi,et al.  Joint torque measurement of a direct-drive arm , 1984, The 23rd IEEE Conference on Decision and Control.

[4]  Kazuhito Yokoi,et al.  On a New Torque Sensor for Compliant Grasp by Robot Fingers with a Tendon Actuation System , 1989 .

[5]  Shigeki Sugano,et al.  CONSIDERATION OF VELOCITY TERMS IN FINGER-ARM COORDINATION MOTION PLANNING , 1988 .

[6]  Chae-hun An.  Trajectory and force control of a direct drive arm , 1986 .

[7]  J. S. Luh,et al.  Joint torque control by a direct feedback for industrial robots , 1981, 1981 20th IEEE Conference on Decision and Control including the Symposium on Adaptive Processes.

[8]  G. Siouris,et al.  Nonlinear Control Engineering , 1977, IEEE Transactions on Systems, Man, and Cybernetics.

[9]  Stephen C. Jacobsen,et al.  Design of the Utah/M.I.T. Dextrous Hand , 1986, Proceedings. 1986 IEEE International Conference on Robotics and Automation.

[10]  T. J. Doll,et al.  The Karlsruhe Hand , 1988 .

[11]  E. A. Freeman.  The effect of speed-dependent friction and backlash on the stability of automatic control systems , 1959, Transactions of the American Institute of Electrical Engineers, Part II: Applications and Industry.

[12]  Kazuhito Yokoi,et al.  Development of a two-fingered robot hand with capability of adjusting compliance. , 1989 .

[13]  J. Kenneth Salisbury,et al.  Articulated Hands , 1982 .

[14]  John Kenneth Salisbury,et al.  The Effect of coulomb friction and stiction on force control , 1987, Proceedings. 1987 IEEE International Conference on Robotics and Automation.

[15]  Giorgio Buttazzo,et al.  An Anthropomorphic Robot Finger for Investigating Artificial Tactile Perception , 1987 .

[16]  E. A. Freeman.  The stabilization of control systems with backlash using a high-frequency on-off loop , 1960 .

[17]  Claudio Melchiorri,et al.  CONTROL SYSTEM DESIGN OF A DEXTEROUS HAND FOR INDUSTRIAL ROBOTS , 1988 .

[18]  Tokuji Okada,et al.  Object-Handling System for Manual Industry , 1979, IEEE Transactions on Systems, Man, and Cybernetics.

[19]  Tokuji Okada.  Force Control of an Artificial Finger Driven by a Hose-Guided Wire , 1978 .

[20]  Max Donath,et al.  ROBOT HAND IMPEDANCE CONTROL IN THE PRESENCE OF MECHANICAL NONLINEARITIES. , 1985 .