Development Of Hardware-in-the-Loop Test Rig Of Steer-by-Wire And Research On The Control Methods

Steering-by-Wire (SBW) is a kind of brand-new concept for the design of steering system,in which lots of advanced electronic technology,information technology and control theory have been adopted now. Steering manipulation is detected by angle sensor and torque sensor, then these signals are transferred to the central controller, which uses these signals and the other sensor's signals to control the steering angle of front wheel and steering wheel torque. Since there is no conflict between the desirable steering ratio and steering wheel torque,we can freely control the steering angle of front wheel and design the steering wheel torque characteristic. That could greatly improve the security of vehicle system and make drivers feel more comfortable during driving. As a brand-new vehicle steering system, Steer-by-wire system own special structure so it still don't implement production. Before Steer-by-wire system being used realistically, we must make sure it own good reliability, from this the important of Steer-by-wire system test rig show completely. Use Steer-by-wire system test rig to do enough experiments, debugging and improving the systems, making sure its reliability.In this paper, we based on diminutive simulator, achieved the Steer-by-wire system hardware-in-the-loop test rig. And made research on the steer control arithmetic, validated the predominance of Steer-by-wire system in the part of vehicle controlling. The paper includes several parts.1,Development of hardware-in-the-loop test rig for SBW system As a valid tool on researching of parts in vehicles, hardware-in-the-loop test rig gets the admission of every great vehicle manufacturers and research department. This paper introduces detailedly the picotal part and parts during the making process of the Steer-by-wire system hardware-in-the-loop test rig.2,Design of road feeling algorithm and steering control algorithm for SBW system. Road feeling algorithm and steering control algorithm are two main control algorithm. Road feeling simulation algorithm includes damp algorithm and return algorithm. Steering control algorithm includes reliability control algorithm and dynamic emendation algorithm. And some experiments had been done on the simulator of hardwire-in-the-loop test rig for Steer-by-wire system.Design a variational ideal steering ratio, make the steer plus fixedness in the meaning of stability. Driver(especially the unprofessional driver) can hold the steering characteristic, drive vehicles easily, lighten the driver's burden. Bring forward a dynamic rectify stability control algorithm basing on the state feedback. Including yaw feedback control, yaw and lateral acceleration feedback control, advancing the stabilization of vehicles.3,Experiments and evaluation in the test rig for SBWOn center steering experiment is the main method to evaluation the road feeling of Steer-by-wire system, through computing and analyzing the evaluation indexes, we can estimate the road feeling simulation algorithm. 8 shape experiments can evaluation the steering portability. Double-lane change experiment is a common method of evaluation of the controllability and stability of vehicles. Through double-lane change experiment we can evaluate steering control algorithm well and truly. Through analyzing the experiments data, we can validate the control algorithm in vehicle manoeuvre.The simulator experiments results indicate, road feeling algorithm make steering portability in low speed and road feeling clearly in high speed; base on the ideal steering ratio, the reliable control strategy can make steer plus fixedness, lighten the burden of drivers, make more people enjoy it; base on state feedback, the dynamic rectify stability control algorithm can advance the stability of vehicle. Through above researches, making a software and hardware foundation of the vehicle realization for steer-by-wire system.