Dual-motor coupling electric power-assisted steering device and control method thereof

Abstract

The invention provides a dual-motor coupling electric power-assisted steering device and a control method thereof. Mode switch is achieved by adopting a magnetic powder clutch and a synchronizer, and a single-row planetary gear system serves as a power coupling device of a first motor and a second motor. A first clutch and a second clutch limit torque output of the first motor and the second motor correspondingly, and the energy flow direction of the second motor is changed through the synchronizer. According to electric current on-off control of an ECU over the clutches, power output of the motors is determined. By using joint conditions of a joint sleeve and combing on-off of the clutches, coupling conditions are determined. According to motor failure and a drive circuit self-diagnosis technology, the power-assisted steering module ECU judges the states of the motors. By controlling the clutches and the joint sleeve, dual-motor fault-tolerant control is achieved. According to the dual-motor coupling electric power-assisted steering device and the control method thereof, four working modes including dual-motor independent drive, dual-motor rotating-speed coupling drive, dual-motor torque coupling drive and the like can be achieved, requirements for various performance of steering in the driving process of a commercial vehicle can be met, and a system is high in reliability.

Description

[0001] 【Technical Field】 [0002] The invention belongs to the technical field of automobile parts, and specifically relates to a dual-motor electric power steering motor coupling system device and a control method thereof. [0003] 【Background technique】 [0004] The electric power steering system has the advantages of good safety and high reliability. At the same time, it adopts a DC motor, does not require the engine to provide high-pressure oil, can obtain optimized power-assisted characteristics, and makes steering light. Because commercial vehicles need to provide large torque when steering, especially for trucks, the required steering torque varies greatly when there is no load, half load, full load and different vehicle speeds. The load capacity obtained through simulation by Wuhan University of Technology Take the maximum steering assist data required under different vehicle loading qualities and different vehicle speeds as an example. As shown in Table 2, this data is discl...

AI Technical Summary

Problems solved by technology

Because a commercial vehicle needs to provide a large torque when turning, especially for a truck, the required steering torque varies greatly when it is empty, half-loaded, full-loaded and at different speeds. Take the maximum power steering data required for vehicles with different loading weights and different vehicle speeds as an example, as shown in Table 2. This data is disclosed in the article Research on Control Strategy of Power Steering System of Large Electric Bus, Master Thesis of Wuhan University of Technology, 2012; of course You can also do your own experiments to get the maximum power steering data required under different vehicle speeds and loading weights. At the same time, due to the limitations of the battery power supply voltage and installation size of the car, the output torque of the electric power steering is small, which cannot meet the requirements of commercial use. The requirements for power steering of vehicles. At present, commercial vehicles developed at home and abroad generally adopt hydraulic power steering systems. Electric power steering instead of hydraulic power steering

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