Rear wheel pulse steering device of four-wheel steering automobile and control method

The invention discloses a rear wheel pulse steering device of a four-wheel steering automobile and a control method. The rear wheel pulse steering device comprises an electronic control unit, a cam gear selecting mechanism, a first steering executing mechanism, a second steering executing mechanism and a traditional steering rack steering mechanism. The electronic control unit obtains information of a steering wheel rotating angle, a front wheel rotating angle and a vehicle speed, judges whether rear wheel steering and rotating direction are conducted or not, and decides to enter a front wheel steering mode, a rear wheel leftward pulse steering mode and a rear wheel rightward pulse steering mode. In different working modes, the electronic control unit controls the rotating speed of a steering motor, disconnection and connection of an electromagnetic clutch and the magnitude of the coil current of an electromagnetic valve, so that the pulse steering angle of the rear wheel is controlled. The device is high in