Fine mechanical impedance control using low-noise Class-G power amplifiers

A fine mechanical impedance control using low-noise Class-G power amplifiers is realized in this paper. In the case of using typical PWM inverter which is categorized as Class-D amplifier, the force and current noise is caused by the PWM switching operations. As a result, the generated mechanical impedance contains the noise. For that reason, the Class-G power amplifiers is used in this research. The force and current noise is reduced by the Class-G amplifiers so that the fine impedance control is achieved. Furthermore, the power efficiency of the Class-G power amplifier is high, compared with another kind of linear amplifiers. By the experiment and analysis of power spectral densities, the validity of the mechanical impedance control using the Class-G power amplifier is verified.