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Reverse parking assist system with automatic steering using
rear view camera
Hisashi Satonaka, Yoichi Iwata,
Hideyuki Iwakiri, Katsuhiko Iwazaki, Tomohiko Endo(Toyota
Motor Corporation)
1.Introduction
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.
2.Technology
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
driverfs 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.
3.Conclusion
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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