Intelligent Sensor Fault Tolerant Research Of Steer By Wire Automobile

In the steer-by-wire automobile, there is no machinery connection between thesteering wheel and road wheel, steering work only depends on the electronic components,how to guarantee when the electronic components failure, the system can achieve its basicfunction still. To solve this problem, the sensor fault-tolerant techniques must be used inthe steer-by-wire system. This paper presents the front corner sensor fault tolerancedesign.In this paper, sensor fault-tolerant control includes the sensor fault judgments module,sensor redundancy signal reconstruction module, sensor fault compensation and isolationmodule research and design.In fault judgments module, based on the defects of the traditional method could notidentify the fault types, this paper proposed a stateflow conditions design, it could identifythree common sensor fault types; In the reconstruction of the redundant signals method, inview of the traditional modeling, easy affected by the influence, this paper adopted thepretreatment method based on rough to find out the relationship variables, take thesevariables to neural network to build the redundant model, then the road wheel angle couldbe estimated; In order to improve the reliability of the system, the LS-SVR is utilized toestimate the body side slip angle, the road wheel angle could estimate by the steeringmodel; In the sensor fault compensation and isolation modules, the switch is slammed, thispaper provides a weighted fusion method, each signal will be given a initialized weights,1for normal working,0for failure, the output value is decided by method of weightedmean.Through the ADAMS and Simulink simulation experiment, the feasibility andeffectiveness of the proposed method and design is proved, in fault judgments, the sensorfault type could be quickly and accurately identified, in the redundant signalsreconstruction, the design possess high precision, strong anti-interference and simplifystructure, compared with the current fault tolerant design model, the structure of thismethod is more simple, and the approximation ability is higher, the design is suitable forcomplicated, nonlinear system identification and modeling. In fault compensation andisolation, weighted fusion fault compensation method has simple structure and highreliability. Compared with the traditional only switch method, the proposed method canfusion two or more redundant signals. Through the overall test show that proposed faulttolerant design is feasible and effective, and it could achieve the purpose of road wheelsensor fault tolerant control.