Evaluation of Basic Driving Characteristics and Implementation of Redundant Speed Limiting Function of a Double-Motor Driving System

The final goal of this paper is to develop an actuator system with high safety and driving performance using a double-motor driving method. In order to realize the goal, firstly, the driving characteristics of the driving method is identified through several experiments. As a result of the experiments, it was clarified that the relationship between rotational speed and torque of the driving method becomes linear in case of a small offset voltage. In addition, it was verified that the motor torque generated by an offset voltage should be larger than the static friction of a gear reducer in order to reduce a backlash on the output shaft. A Safety Related Part (SRP) for the driving system is implemented to avoid an over speed. The SRP consists of two-channel safety parts capable of executing safety function to cut-off power to motors independently. Through several experiments, it was confirmed that the safety function was well conducted in case of a single failure of a sensor system.