Low-noise and fine-efficiency motor drive for motion control

In this paper, Class-G power amplifiers for motion control are developed. General Class-B power amplifier cannot be used for driving high-power actuators because of power efficiency. On the other hand, due to PWM, typical Class-D power amplifier generates switching noise as well as desired current, though the power efficiency is very high. The switching noise cased by PWM inverter degrades the control performance of the motor. In short, typical Class-B and Class-D power amplifiers are not suitable for advanced motion control. By using Class-G amplifier, problem of both power efficiency and noise is able to be solved. Therefore, Class-G amplifier enhances the control performance of current controller for motion control. Driving test of Class-G power amplifiers is conducted. The current controller and force control system are implemented in FPGA. By the experiments, validity of the current control and force control with Class-G power amplifier is verified.