Reverse parking assist system with automatic steering using rear view camera
Hisashi Satonaka,  Yoichi Iwata,  Hideyuki Iwakiri,  Katsuhiko Iwazaki,  Tomohiko Endo(Toyota Motor Corporation)

  This system automatically steers a vehicle when performing reverse parking.  The driver needs to adjust the speed with the brake pedal.  This highly innovative system is designed to automatically steer a vehicle in reverse parking.
This system is expected to:
1. Reduce the driver's load in terms of operating the steering wheel in reverse parking;
2. Minimize the number of attempts to repark; and
3. Make drivers pay more attention to safety verification around the vehicle.

A highly advanced, easy to operate, and still inexpensive parking assist system (I.P.A.) has been developed recently. This system relies on two already commercialized technologies, Back Guide Monitor (BGM), a dashboard display showing the rear image taken by camera, and Electric Power Steering (EPS).
The I.P.A. helps drivers to reduce their load of reverse parking and pay more attention to the surrounding area of the vehicle by controlling steering automatically through an actuator mounted in the steering column          (,Table 1  Figure 1).
System operation behind this innovation works like this: First, the parking trajectory is calculated on the basis of the target parking position set on the backwards-looking video image( Figure 2). This target setting is simplified by accurately estimating the driverfs intended parking spot from past vehicle maneuvers, however, the system never recognizes the frame line of the parking lot.
Then I.P.A. plans the turning curvature in accordance with the vehicle movement by applying clothoid curve and determines the minimized steering angle. This calculation results in the reduction of the actuator load and the vehicle motion.
Next, the steering control is performed to meet the target steering angle which is sent to EPS via Controller Area Network (CAN). Based on steering angle sensor signal and vehicle movement which is calculated from Hybrid Vehicle (HV) main motor rotation angle sensor, present position of the vehicle is specified momentarily.
The smooth steering control and the highly accurate vehicle guidance have been achieved by monitoring and revising the target trajectory.

  This system is installed on the new Prius model, which began sales on September 1, 2003 and has been selling at a rate of approximately 4,000 cars per month. we believe that an even more advanced automatic parking system can be realized through the inclusion of a function for recognizing the parking position and obstacles, as well as a function for controlling the vehicle speed.




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