Integrated design method of force and current control systems

This paper studies an integrated design method of sensorless force control and current control systems. The force control gain, the estimation bandwidth and quality factor of a 1st-order disturbance observer, the proportional and integral gain of an I-P current controllers are determined analytically and numerically by Pole assignment method and Coefficient diagram method(CDM). In the case of Pole assignment and CDM, the force responses converge with the force command without any oscillations and overshoot. By the simulations and experiment, the validity of the integrated design method proposed in this paper is verified. Furthermore, this paper presents that not only the parameters of the force control system but also the gain of the I-P current controllers have to be varied depending on the environmental stiffness.