Research On The Simulation Of Steering Reaction Torque In Steer-by-Wire System

Steer-by-wire system has the advantages that the conventional steeringsystem difficult to achieve in the aspect of intelligent controlling of vehicle andthe safe driving with the conventional mechanical connection between steeringhand wheel and the front wheel being replaced by electrical signals. So the steer-by-wire system becomes the future direction of development of automotivesteering systems, and the characteristics of the steering feel will impact theperformance of SBW directly. This paper research the steering recreation torqueon steer-by-wire system, and the goal of this paper is realizing the planningsteering torque.In this paper, according to the forming principle of steering torque ofconventional steering system, the steering feedback torque (i.e. steering feel) onthe steering wheel of steer-by-wire system is planned. The planning of steeringfeel is realized by superposition of steering resist torque and compensatorytorque of steering, where the steering resist torque is calculated based on theclassic bicycle model. The compensatory torque is similar to the power torqueprovided by hydraulic or motor in the conventional steering system. In this papera linear assist torque will be used.The simulation results show that the properties of steering torque byplanning are almost the same with that of the torque of conventional steering.The simulation results in the test of steering wheel aligning and the steeringwheel transient response meet the evaluation index of the method of Vehiclehandling and stability testing.A test bench of steering torque recreated system is set up to further verifythe planning steering torque by the hardware in the loop simulation combiningwith dSPACE. This paper design the hardware circuit of steering torquerecreating system, and the designed process is analyzed. The hardware circuit isdivided into two parts, the control circuit and the driver circuit. Control circuit used TMS570as the master chip, and the resolver signal processing circuitamong control circuit is carried out a detailed design and the simulation resultsare given. The dirver circuit includes inverter circuit, protection circuit, and soon. The results of driver circuit testing are given finally. The test of steeringwheel aligning and the steering wheel transient response will be done in thehardware in the loop experiment, also the test of comparison between theplanning steering torque and the real steering torque, and the data of pivotsteering in the real car are acquired to compare with that in SBW system. Theexperiment results basically meet the evaluation index, and the steering torquecan be actually felt. So the function of steering torque recreated system isbasically achieved.