A variable transmission ratio optimization design method of a multi-mode drive-by-wire power steering system and a special system thereof

Abstract

The invention discloses a variable transmission ratio optimization design method of a multi-mode drive-by-wire power steering system and a special system thereof. The method comprises the following steps: 1) establishing a drive-by-wire power steering system dynamic model; 2) establishing road feel and sensitivity evaluation indexes of the steer-by-wire system; Step 3) starting to increase progressively at the speed of 25km / h, and setting 10 groups of vehicle speeds; 4) taking the steering transmission ratio as an optimization variable, determining the transmission ratio under the fixed yaw velocity gain and the fixed lateral acceleration gain according to the automobile parameters and the automobile speed, taking the transmission ratio as a design space of the transmission ratio, and taking the steering road feel and the steering sensitivity as optimization objectives to establish a multi-objective optimization model; Step 5) According to the transmission ratio optimization result, adopting the smooth curve to perform fitting to obtain an optimized design result. According to the transmission ratio optimization method of the steering system, through further optimization design ofthe transmission ratio of the steering system, the road feel and sensitivity of automobile steering are considered, the comprehensive performance of the steering system can be effectively improved, and the driving experience of a driver is improved.

Description

technical field [0001] The invention relates to the field of power-by-wire steering, in particular to an optimal design method for variable transmission ratio of a multi-mode power-by-wire steering system based on steer-by-wire and a special system thereof. Background technique [0002] Steering system is one of the key parts of the car. The driver controls the direction of movement of the car through the steering system. Therefore, the design of the steering system directly affects the safety of the car, the stability of the steering and the comfort of driving. The steer-by-wire system is a new generation of steering system. Because the mechanical connection between the steering wheel and the steering wheel is canceled, it is also called a flexible steering system. The power steering system by wire control completely gets rid of the various limitations of the traditional steering system. The driver's steering operation is only to input the steering wheel angle signal comman...

AI Technical Summary

Problems solved by technology

[0003] However, the current power steering system on the market is mainly used in cars, and there are few reports about power steering for commercial vehicles with large front axle loads.

Secondly, it is difficult for a single driving mode to meet the different requirements of drivers. Steering by wire cancels the mechanical connection, which facilitates the layout of the mechanical structure, but the driver is also isolated from the real road feeling; The design of the variable transmission ratio of automobiles is less involved. The existing variable transmission ratio design is mainly based on the constant gain of the yaw rate or the constant gain of the lateral acceleration of the vehicle. Coupling Control Research", but this design method ignores the driver's driving experience at different speeds, making it difficult for the driver to feel the difference in different steering conditions while maintaining driving stability, and the steering feels dull

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