Steering-by-wire system test bench

Abstract

The invention discloses a steering-by-wire system test bench, which comprises the design of a master control module, a fault-tolerant module, a steering control module, a steering execution module and a resistance loading module and connection parts thereof. A steering wheel is connected with a steering-column-assisted type steering gear to simulate road surface feedback; and two pinion-and-rack type steering gears with different power are connected by means of the parts, receive sensor signals by means of a master control single chip microcomputer, and realize steering and resistance simulation through transmitting PWM signals by using an Flexray bus. The mechanical connection between steering execution and operation is reduced, a transmission ratio and road feeling can be designed freely to change force transmission characteristic and angle transmission characteristic of the system, the layout space of a vehicle is saved, and the operation stability of the vehicle is improved. The steering-by-wire system test bench can simulate the road surface resistance in various states, and improves the precision of the system. The construction method of the SBW test bench disclosed by the invention is simple and effective, and can be applied to the experimental study of an SBW system control algorithm, a fault-tolerant algorithm and a bus technology.

Description

Technical field [0001] The invention relates to a wire-controlled steering system, namely an SBW test bench, which belongs to the technical field of automobile steering. Background technique [0002] In recent years, due to market demand and the development of electronic technology, automobiles have begun to become intelligent. In the field of steering, there have been mechanical steering systems, hydraulic power steering systems (HPS), electro-hydraulic power steering systems (EHPS), and electric power steering systems. (EPS) is developing towards Steer-By-Wire (SBW). The EPS system is divided into steering column assist type (C-EPS), steering pinion assist type (P-EPS), rack assist type (R-EPS). The DC motor-based EPS technology has matured and is widely used in real cars. Due to factors such as cost and stability, the steering-by-wire technology has not been popularized in low-priced family cars. [0003] At present, the known SBW system basically selects motors, reducers, ra...

AI Technical Summary

Problems solved by technology

[0003] At present, the known SBW system basically selects motors, reducers, rack and pinion steering gears and other components separately to assemble the steering control structure and steering execution structure, and the assembly error is difficult to control; most of them use CAN bus to realize single-chip communication, and the maximum performance limit is 1Mbps , the transmission speed is slow, and the real-time control effect is average. The rapidity and accuracy of the control of the SBW system put forward higher requirements for the bus system; most of the current resistance loading mechanisms use springs and magnetic powder brakes, and the change law of spring-loaded resistance is constant. Magnetic powder brakes are prone to control errors and unstable moisture performance

[0004] The SBW system proposed in Hunan University's master's degree thesis "In-the-Loop System Simulation Based on Automobile Steering by Wire Test Bench" uses a servo motor resistance loading mechanism, and connects the ball screw with the motor reducer to output resistance torque to the SBW system. The bearing capacity of the ball screw is low, the cushioning performance is low and there is wear and tear, which will affect the positioning accuracy and rigidity due to friction, and the friction torque will also cause a sudden jump when reversing

[0005] At present, there are few related literatures that directly use the mechanical structure of the EPS steering machine as the steering mechanism, steering actuator and resistance loading mechanism of the SBW system.

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