ELECTRIC POWER STEERING DEVICE

摘要

PURPOSE:To improve steering feeling in an electric power steering device without generation of oscillation at the time of steering an operation handle and generation of follow-up delay of the assist torque. CONSTITUTION:The output signal from a torque sensor 12 is input to a CPU 20 through an integration circuit 15 and an A/D converter 18. Simultaneously, the output signal from the torque sensor 12 is input to the CPU 20 through an A/D converter 19. In this CPU 20, duty ratio against a differential value of the torque is computed. The PWM signal on the basis of that duty ratio is input to a gate of a FET connected in parallel with a resistance element R1 of the described integration circuit 15. Namely, time constant of the integration circuit 15 is changed by a combined resistance value of the resistance element R1 and a resistance element R2, which is connected with the FET. In the case that an operation handle 10 is steered early, the assist torque is generated quickly, and in the case that the operation handle 10 is steered later, generation of oscillation is eliminated.