A sensorless force control in twin drive system

This article describes the method of a sensorless force control in a twin drive system. The twin drive system is composed of two motors connected by a differential mechanism. Its generated output is the difference of torque between two motors. Since its two motors can continue to drive even when the system makes a stationary motion, the effective static friction of the system is drastically reduced. The disturbance torque is so small, this system is able to estimate the external disturbance torque more than usual motor. By using this system, it is possible to construct the force sensorless controller more exactly.