Development of “Steering System for Steer-by-Wire”March 25, 2011
NTN Corporation (hereafter, NTN) has developed a “Steering system for steer-by-wire*1” as a next-generation vehicle steering system, which transmits the steering wheel operation by an electrical signal.
The following effectiveness can be acquired by changing the steering system from mechanical control to electronic control.
- Improves the flexibility of the layout of the steering system.
(Example: Eliminates the replacement of right and left steering wheels and shock absorbers at the time of a collision.) - Properly controls the wheel-turning actuator and achieves a stable and comfortable behavior automatically.
(Example: Prevents the unsteadiness of the vehicle caused by side winds.)
The “Steering system for steer-by-wire” developed by NTN, is equipped with a sub-motor for right and left independent wheel-turning operations including a main motor for the wheel-turning operation, and is the world's first system to secure safety by instantly switching the sub-motor to a wheel turning function at the time of a failure, such as the burning out of the main motor. The sub-motor for right and left independent wheel-turning operations achieves both improved driving stability and reduces the running resistance according to the conditions of the vehicle, by controlling the aperture angle (toe angle) of the tires in contrast to the vehicle traveling direction.
*1 Except for the mechanical link mechanism between the steering wheel and the steering gear box, this system changes the steering amount to an electrical signal to drive the wheel-turning actuator according to the amount, and changes the direction of the tires (wheel-turning).
Features
(1) Failsafe Mechanism |
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(2) Aperture angle (toe angle) control by a sub-motor |
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(3) Simple advancement of vehicle safety control |
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(4) Automatic adjustment of power required for steering wheel operation |
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Application
Next-generation vehicle steering system