| 摘要 |
<p>PURPOSE:To protect an electric motor from being damaged by the generated heat, by controlling the electric conduction rate of the electric motor according to the electric current value which flows in an H-bridge circuit for driving a steering electric motor, in the constitution in which a rear wheel steering mechanism is driven by the steering electric motor. CONSTITUTION:The steering angle ratio is calculated in correspondence with the front wheel steering angle or car speed by a CPU 8 in a controller, and a rear wheel steering mechanism is controlled by the drive of a steering electric motor 2a according to the calculated steering angle ratio. An H-bridge circuit which is constituted of power transistors Q1-Q4 and drives the steering electric motor 2a is installed into the controller. The electric current which flows in the H-bridge circuit is detected by detecting the electric voltage which is generated in a resistance R1, and the electric conduction rate of an electric motor 1a is controlled according to the detected electric current value. Therefore, in case of the excessive electric current, etc. the need of immediately suspending the electric conduction of the electric moor 2a is obviated, and the control is continued for a long time.</p> |
