A method and device for determining the power assist current of an electric power steering system

Abstract

The invention discloses a method for determining the power-assisting current of an electric power-assisted steering system, which comprises the following steps of: obtaining maximum power-assisting current, minimum power-assisting current and threshold speed; obtaining the speed value of an automobile; comparing the speed value with the threshold speed; when the speed value is larger than the threshold speed, determining the minimum power-assisting current as the power-assisting current of the electric power-assisted steering system; and when the speed value is smaller than or equal to the threshold value, determining the power-assisting current of the electric power-assisted steering system according to the corresponding relation between the power-assisting current and the speed. By adopting the method disclosed by the invention, the power-assisting current can be determined under the situation that road testing is not conducted, the development cost can be reduced, the power-assisting current corresponding to any speed within maximum design speed can be determined, the generated steering assisting power is more accurate by following the requirement that the speed is approximately in inverse proportion to the power-assisting current within the range of the threshold speed, and the stability and the portability of the electric power-assisted steering system are improved. The invention additionally discloses a device for determining the power-assisting current of the electric power-assisted steering system.

Description

technical field [0001] The invention belongs to the technical field of electric power steering systems of automobiles, and in particular relates to a method and a device for determining the power assist current of the electric power steering system. Background technique [0002] The electric power steering system is a power steering system that directly relies on the motor to provide auxiliary torque. Compared with the traditional hydraulic power steering system, the electric power steering system only provides assistance when the motor is turning, which can significantly reduce fuel consumption. Electric power steering systems are widely used in current cars. [0003] In the electric power steering system, the lightness of steering at low speeds and the operational stability at high speeds can be taken into account by adjusting the magnitude of the steering assist. At low speeds, the electric power steering system can provide greater steering assistance and provide the veh...

AI Technical Summary

Problems solved by technology

[0005] However, in the above-mentioned process of determining the power assist current of the electric power steering system, it is necessary to conduct road tests many times, which will consume a lot of fuel and require a lot of manpower, resulting in a lot of development costs, and is limited by the development costs. Only the assist current corresponding to each speed range can be determined, and each speed value in a certain speed range corresponds to a unified assist current, which cannot meet the requirement that the speed and the assist current are approximately inversely proportional, and the resulting steering assist has deviations, which can easily lead to Reduced steering ease and stability

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