Active vibration insulator

摘要

An active vibration insulator (1) includes an electromagnetic actuator, a control-signals generating device, a driver (16), a calculator, and a judging device. The electromagnetic actuator generates vibrating forces depending on electric-current supplies. The control-signals generating device (14) generates cyclic control signals based on cyclic pulsating signals output (G) from a vibration generating source of a vehicle. The cyclic control signals actively inhibit vibrations generated by the vibration generating source from transmitting to a specific part of the vehicle. The driver (16) drives the electromagnetic actuator by making the electric-current supplies variable based on the cyclic control signals. The calculator calculates an estimated transfer function composed of estimated values of a transfer function for a transfer system (C) including the electromagnetic actuator and the driver (16). The judging device judges an inoperative malfunction of the electromagnetic actuator based the estimated transfer function.