Abstract: A power steering apparatus for an electric vehicle has a steering mechanism for steering a pair of steered wheels upon receiving assist power from a steering assist-power according to a steer force required for steering the steered wheels. A fluid pressure pump driven by an electric motor supplies pressurized fluid to the steering assist-power mechanism. An electric motor controller stops the electric motor when the electric-source voltage detected by an electric source voltage detector is greater than or equal to a voltage set value and when the steer angle detected by a steer angle detector is smaller than a steer angle set value, and prohibits stopping the electric motor when the electric-source voltage is smaller than the voltage set value. Therefore, it becomes possible to ensure the steering responsiveness under an electric voltage lowered condition while avoiding the disturbance to the electric source.

Abstract: Disclosed is a series connection circuit for secondary batteries for preventing a reduction of energy usable as the builtup battery due to a difference of DOD of the batteries and a difference of voltage detection level of voltage detectors. The circuit includes voltage detectors for detecting the terminal voltage of the secondary batteries thereby to calculate the respective values of DOD thereof, transistors for discharging the secondary batteries independently, a charging unit to charge the secondary batteries and a controller for controlling the independent discharging operation of the transistors corresponding to the respective values of DOD. With the arrangement mentioned above, it is possible to equalize the values of DOD, whereby the reduction of usable energy caused by the increasing of difference of DOD can be prevented.

Abstract: A wheel motor drive system for electric automobiles comprises a car battery mounted on a vehicle body, at least two electric motors connected to vehicle wheels independently of each other, each of the motors having inherent torque characteristics with regard to a rotational speed and a maximum torque, sensors for monitoring a vehicle travelling condition, and a controller responsive to the vehicle travelling condition and the torque characteristics of the motors for controlling the motors at a low power consumption mode wherein at least one of the motors is driven within a high motor efficiency range so as to assure a long travel distance per one battery discharge.

Abstract: A rear wheel steering control system is provided. This system includes a traction control system which is responsive to generation of a difference in rotational speeds between front and rear wheels to recover traction of driven wheels and a compensating system which corrects a rear wheel steering angle, determined in a preselected relation to vehicle speed and a steered angle of the front wheels, based on the difference in rotational speeds between the front and rear wheels to provide a proper rear wheel target steering angle. The system restricts operation of the compensating system during operation of a traction control system to prevent a hunting frequency thereof from affecting the operation of the compensating system.

Abstract: A system for controlling a steering angle for the rear wheels of a vehicle is provided. This system includes generally, a torque sensor for detect torque of driven wheel, an angle sensor for sensing a steered angle of front wheels, a steering controller for determining a rear wheel target steering angle, and an actuator for steering the rear wheels by the rear wheel target steering angle. The steering controller first determines a rear wheel steering angle based on the steered angle of the front wheels and then calculates a correction for the rear wheel steering angle according to variation in the torque of the driven wheels during running to determine the proper rear wheel target steering angle.

Abstract: Steering angle for rear wheels of a vehicle is controlled by determining a rear wheel steering angle in a preselected relation to a steered angle of a steering wheel. A correction factor for the rear wheel steering angle is based on a difference in rotational speed between front and rear wheels induced during turning. The correction factor for rear wheel steering angle is maintained at the value it had prior to braking to cancel the effect of braking slips on the determination of the rear wheel steering angle to improve steering stability.

Abstract: A system for controlling a steering angle for the rear wheels of a vehicle is provided. This system includes generally a rotational speed sensor for detecting rotational speeds of front and rear wheels to provide a difference in rotational speeds between the front and the rear wheels, an angle sensor for sensing a steered angle of a steering wheel, a steering controller for determining a rear wheel target steering angle, and an actuator for steering the rear wheels by the rear wheel target steering angle. The steering controller calculates a component of a difference in rotational speeds between the front and rear wheels caused by a difference in turning tracks therebetween and compensates for this component by the difference derived by the rotational speed sensor to provide a correction value for the rotational speeds between the front and rear wheels caused by acceleration during turning as a correction for a rear wheel steering angle.