A parallel structure dual-motor electric power steering system and power steering method

Abstract

The invention relates to a dual-motor electric power steering system adopting a parallel connection structure and a power steering method. The dual-motor electric power steering system comprises a steering wheel rotating angle and position sensor, wherein the steering wheel rotating angle and position sensor and a steering wheel torque sensor are arranged under a steering wheel; the steering wheel and wheels are connected with a steering gear; the steering gear is connected with a dual-motor system adopting a parallel connection structure; and the steering wheel rotating angle and position sensor, the steering wheel torque sensor, a vehicle speed sensor and the dual-motor system adopting the parallel connection structure are separately connected with an electric control unit (ECU). According to the dual-motor electric power steering system disclosed by the invention, through the ECU, a control current of each motor in the dual-motor system is changed, so that an assist characteristic curve is flexibly changed, and contradiction of steering between 'portability' and 'flexibility' is well coordinated, so that the operation is stable; four working modes of a dual-motor torque coupling power steering mode, a main motor power steering mode, a damp control mode and a returning control mode can be realized, so that not only is the steering portability guaranteed, but also the driving comfortableness and the driving safety are improved.

Description

technical field [0001] The invention relates to the technical field of power steering, in particular to a parallel structure dual-motor electric power steering system and a power steering method. Background technique [0002] At present, all commercial vehicles use hydraulic power steering. Although the power steering of commercial vehicles has been realized, there are many disadvantages: the oil pump is driven by the engine and works continuously, and consumes a lot of energy; hydraulic oil leaks and rubber tubes pollute the environment; power characteristics and control The valve structure is related. Once the system is finalized, the power assist characteristics cannot be changed; the power assist has nothing to do with the vehicle speed, and the contradiction between steering convenience and road feel cannot be coordinated. The existing electric power steering system has high safety and reliability, and the steering characteristic curve is ideal. At the same time, due t...

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Problems solved by technology

[0002] At present, all commercial vehicles use hydraulic power steering. Although the power steering of commercial vehicles has been realized, there are many disadvantages: the oil pump is driven by the engine and works continuously, and consumes a lot of energy; hydraulic oil leaks and rubber tubes pollute the environment; power characteristics and control The valve structure is related. Once the system is finalized, the power assist characteristics cannot be changed; the power assist has nothing to do with the vehicle speed, and the contradiction between steering convenience and road feel cannot be coordinated, etc.

However, due to the limitation of installation size and other aspects, the output torque of electric power steering is small, which cannot meet the requirements of commercial vehicle steering assistance. At present, the application field is still limited to passenger cars or light commercial vehicles.

In the steering system of commercial vehicles, the space for arranging the power-assisted motor is very limited. The proposed dual-motor ideal structure is too complicated and takes up a lot of space.

[0003] The power steering system on traditional commercial vehicles mostly adopts hydraulic power steering system, but there are great defects in the use of hydraulic power steering. The relationship between portability and road feel is very difficult, which affects the handling stability; at the same time, the oil pump keeps running when not turning, which increases energy consumption; there are oil leakage and maintenance problems, which increase the maintenance cost, and the leaked hydraulic oil will affect the environmental pollution

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