Development of an Actuator with ER Damper and Its Basic Experiments

Abstract

Most industrial robots are driven through reduction gear units by DC or AC servomotors. The elasticity of the drive systems including these reduction gear units cannot be ignored when the high-speed and precise motion control is required for robots. Due to the elasticity of the drive systems, the vibratory behaviors are caused, and the control performances of robot systems are deteriorated. In this study, we develop a new actuator, which consists of an AC servomotor, a harmonic drive gear and an ER damper. Since the gap between electrodes of the ER damper is 80 [Rm], only the voltage of 80 [V] is needed for the electric field of 1 [kV/mm]. And this ER damper consumes little electric power. The actuator is installed to the one-link robot arm. The mathematical model of the robot arm is derived, and the eigenvalues of the robot system are analyzed. The experiments are conducted, and the effectiveness of the actuator is shown.

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References

1. M. C. Good and L. M. Sweet , "Dynamic Models for Control System Design of Integrated Robot and Drive Systems," ASME J. Dynamics Systems, Measurement, and Control, Vol. 107, No. 1, pp. 53-60 (1985).

2. J. Furusho , H. Nagao and M. Naruse , "Multivariable Root Loci of Control Systems of Robot Manipulators with Flexible Driving Systems," JSME Int. J., Series III, Vol. 35, No. 1, pp. 65-73 (1992).

3. J. Y. S. Luh , "Conventional Controller Design for Industrial Robots-A Tutorial," IEEE Trans. on Systems, Man, and Cybernetics, Vol. SMC-13, No. 3, pp. 298-316 (1983).

4. T. C. Jordan and M. T. Shaw , "Electrorheology (Review Article)," IEEE Trans. on Electrical Insulation, Vol. 24, pp. 849-878 (1989).

5. J. Furusho , "Control of Mechatronics Systems Using Electrorheological Fluids (Review Article)," (In Japanese), J. of SICE, Vol. 34, pp. 687-691 (1995).

6. A. Inoue and S. Maniwa , "Electrorheological Effect of Liquid Crystalline Polymers," J. Applied Polymer Science, Vol. 55, pp. 113-118 (1995).

7. A. Inoue, Y. Ide , S. Maniwa , H. Yamada , and H. Oda , "Properties of ER Fluids Comprised of Liquid Crystalline Polymers," Proc. Int. Conf on ER Fluids, MR Suspension and Their Applications, pp. 384-392, World Scientific (1997).

8. J. Furusho , G. Zhang and M. Sakaguchi , "Vibration Suppression Control of Robot Arms Using a Homogeneous-Type Electrorheological Fluid," IEEE Proc. Int. Conf on Robotics and Automation, Vol. 4, pp. 3441-3448 (1997).

9. N. Takesue , G. Zhang , J. Furusho and M. Sakaguchi , "Precise Position Control of Robot Arms Using a Homogeneous ER Fluid," IEEE Proc. Int. Conf. on Robotics and Automation, Vol. 3, pp. 2470-2475 (1998).

10.

10. N. Takesue , G. Zhang , J. Furusho , and M. Sakaguchi , "High Stiffness Control of Direct-Drive Motor System by a Homogeneous ER Fluid," IEEE Proc. Int. Conf on Robotics and Automation, Vol. 1, pp. 188-192 (1999).