Design of an Adaptive Fuzzy Estimator for Force/Position Tracking in Robot Manipulators

Document Type: Research Paper


1 Department of Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran

2 Department of Electrical and Computer Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran

3 Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran


This paper presents a stable new algorithm for force/position control in robot manipulators. In this algorithm, position vectors are measured by sensors and then used in the control law. Since using force sensor has some issues such as high costs and technical problems, an approach is presented to overcome these issues. In this respect, force sensor is replaced by an adaptive fuzzy estimator to estimate the external force based on position and velocity measurements. In this approach, force can be properly estimated using universal approximation property of fuzzy systems. Therefore, robots can be controlled in different environments even when no exact mathematical model is available. Since this approach is adaptive, accuracy of the system can be improved with time.  Through a theorem the stability of the control system is analyzed using Lyapunov direct method. At last, satisfactory performances of the proposed approach are verified via some numerical simulations and the results are compared with some previous approaches.


C. H. An and J. M. Hollerbach, {it Kinematic stability issues in force control of manipulator}, International Conference on Robotics and Automation, IEEE Robotics and Automation society Raleigh, North Carolina, (1987), 897-903.

M. Bernhardt, M. Frey, G. Colombo and R. Riener, {it Hybrid force-position control yields cooperative behaviour of the rehabilitation robot LOKOMAT}, IEEE Int. Conf. on Rehabilitation Robotics, (2001), 536-539.

J. A. Briones, E. Castillo, G. Carbone and M. Ceccarelli, {it Position and force control of the CAPAMAN 2 bis parallel robot for drilling tasks}, IEEE Int. Conf. on Electronics, Robotics and Automotive Mechanics, (2009), 181-186.

J. J. Craig and M. H. Raibert, {it A systematic method of hybrid position/force control of a manipulator}, In Computer Software and Applications Conference, IEEE Computer Society Chicago, Illinois, (1979), 446-451.

M. Danesh, F. Sheikholeslam and M. Keshmiri, {it A force estimator based algorithm for robot control},
IEEE Int. Conf. on Mechatronics, (2005), 376-381.

M. Danesh, F. Sheikholeslam and M. Keshmiri, {it External force disturbance rejection in robotic arms an adaptive approach}, IEICE Trans. on Fundamentals, {bf E88-A}textbf{(10)} (2005), 2504-2513.

M. Danesh, F. Sheikholeslam and M. Keshmiri, {it An adaptive manipulator controller based on force and parameter estimation}, IEICE Trans. on Fundamentals, {bf E89-A}textbf{(10)} (2006), 1-9.

E. C. Dean-Le´on, L. G. Garc-Valdovinos and V. Parra-Vega , {it Uncalibrated image based position-force adaptive visual servoing for constrained robots under dynamic friction uncertainties}, IEEE Int. Conf. on Mechatronics and Automation, (2006), 1-8.

G. Duchemin, P. Maillet, P. Poignet, E. Dombre and F. Pierrot, {it Hybrid position/force control approach for identification of deformation models of skin and underlying tissues}, IEEE Trans. on Biomedical Engineering, {bf 52}textbf{(2)} (2005), 160-170.

K. S. Eom, I. H. Suh, W. K. Chung and S. R. Oh, {it Disturbance observer based force control of robot manipulator without force sensor}, Proc. of ICRA98, (1998), 3012-3017.

Q. Huanga and R. Enomoto, {it Hybrid position, posture, force and moment control of robot manipulators}, IEEE Int. Conf. on Robotics and Biomimetics, (2009), 1444-1450.

F. Inoue, T. Murakami and K. Ohnishi, {it A motion control of mobile manipulator with external force}, EEE/ASME Trans. on Mechatronics, {bf 6}textbf{(2)} (2001), 137-142.

T. Murakami, R. Nakamura, F. Yau and K. Ohnishi, {it Force sensorless impedance control by disturbance observer}, PCC-Yokohama, (1993), 352-357.

J. Roy and L. L. Whitcomb, {it Adaptive force control of position/velocity controlled robots: theory and experiment}, IEEE Trans. on Robotics and Automation, {bf 18}textbf{(2)} (2002), 121-137.

J. D. Schutter and H. Van Brussel, {it Compliant robot motion II. a control approach based on external control loops}, Int. J. Robot. Res., {bf 7}textbf{(4)} (1988), 18-33.

M. Shaung Ju, C. Ching, K. Lin, D. Huang Lin, I. S. Hwang and S. M. Chen, {it A rehabilitation robot with force-position hybrid fuzzy controller: hybrid fuzzy control of rehabilitation robot}, IEEE Trans. on Neural Systems and Rehabilitation Engineering, {bf 13}textbf{(3)} (2005), 349-358.

J. J. E. Slotine and W. Li, Applied Nonlinear Control, Prentice-Hall, 1991.

T. Tsuji, Y. Kaneko and S. Abe, {it Whole-Body force sensation by force sensor with shell-shaped end-effector}, IEEE Trans. on Industrial Electronics, {bf 56}textbf{(5)} (2009), 1375-1382.

R. J. Wai and Z. W. Yang, {it Adaptive fuzzy-neural-network control of robot manipulator using T-S fuzzy model design}, IEEE Int. Conf. on Fuzzy Systems, (2008), 90-97.

R. J. Wai and Z. W. Yang, {it Adaptive fuzzy neural network control design via a T-S fuzzy model for a robot manipulator including actuator dynamics}, IEEE Trans. on Systems, Main, And Cybernetics Part B: Cybernetic, {bf 38}textbf{(5)} (2008), 1326-1346.

L. L. Whitcomb, S. Arimoto, T. Naniwa and F. Ozaki,, {it Adaptive model-based hybrid control of geometrically constrained robot arms}, IEEE Trans. on Robotics and Automation, (1997), 105-116.

H. Zhang, {it Kinematic stability of robot manipulators under force control}, International Conference on Robotics and Automation, IEEE Robotics and Automation Society Scottsdale, Arizona, (1989), 80-85.

H. Zhang and R. P. Paul, {it Hybrid control of robot manipulators}, International conference on Robotics and Automation, IEEE Computer Society St. Louis, Missouri, (1985), 602-607.