Electric power steering system
AssigneeHonda Motor Co., Ltd.
InventorYasuo Shimizu
Life of this patent
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Abstract
An electric power steering system includes a steering wheel, a rack-and-pinion type steering gear box connected to the steering wheel, a steering torque sensor, a pinion shaft, and a steering actuator mounted on the pinion shaft to assist a steering operation conducted by a driver. An overload preventing control is conducted so that a sum of a current conversion value of a steering torque detected by the steering torque sensor and an assist current calculated based on the steering torque becomes equal to a limit value. When the steering gear box has reached a stroke end, the assist current is prevented from excessively increasing, thereby preventing a reduction in durability of the steering gear box or a motor of the steering actuator.
Claims12
An electric power steering system comprising:
- a steering wheel;
- a rack-and-pinion steering gear box connected to the steering wheel;
- a steering torque sensor for detecting a steering torque input to the steering wheel;
- and
- a steering actuator driven by an assist current calculated based on the steering torque;
- wherein an overload preventing control for limiting the driving of the steering actuator is conducted, wherein a sum of the assist current and a current conversion value of the steering torque detected by the steering torque sensor equals a predetermined threshold value.
Dependencies are inferred from the claim text.