European Patent Number 1954547
Chineese Patent Number CN 101370701
Patent Pending in USA, Japan, India and South Korea
Basic Principle of the System
The system basically consists of two separate systems; a control system that enables the driver to control the steerable wheels of the car and a feedback system allows the driver to sense the reaction of the steerable wheels in the steering wheel.
The torque the driver applies on the steering wheel is transmitted by the control system to the steerable wheels. The driver thus controls the force that is applied by the tie rods on the steerable wheels.
The position of the steering wheel is controlled by the feedback system, so that the position of the steering wheel always corresponds to the position of the steerable wheels. Therefore, the driver can not be allowed to move the steering wheel, but only exert a force on it and only the system can actually move the steering wheel.
In combination, the two systems provide a steer-by-wire system with tactile feedback. When the driver applies a force on the steering wheel, an equivalent force is applied by the tie rods on the steerable wheels. If the force applied by the tie rods on the steerable wheels exceeds friction and other forces acting on the steerable wheels, the steerable wheels will move. As soon as the steerable wheels start to move, so will the steering wheel. In that way, the driver will sense a resistance in the steering wheel equivalent to the friction and other forces acting on the steerable wheels. To the driver, it will feel as if it is the driver and not the system that moves the steering wheel. If conditions change and the forces acting on the steerable wheels increase to a degree where the force applied by the tie rods are no longer exceeding the road forces, the steerable wheels will stop moving or even start to move in the other direction. This will result in a similar stop of motion of the steering wheel or even a motion in the opposite direction of the steering wheel, unless the force applied on the steering wheel by the driver is increased.
For a more descripted explanation of our steer-by-wire system and its working principle, we kindly refer you to the other pages on this website. You may choose to read directly from the webpages, or you have the possibility to download the information. Thank you!