Research On Automatic Detection System Of Automobile Steering Mechanism

The steering system of automobile plays an important part, and the structureand techno-capability of automobiles' steering system is very significant to thesafety driving. If there's something wrong with the steering system, it is easy tolead to disastrous accidents. The national standards GB 18565-2001 "Multipleperformance requirement and detecting methods for commercial vehicles" andThe national standards GB 7258-2004 "Safety specifications for power drivenvehicles operating on roads" gives relative rules on max angle, free play ofsteering wheel and steering moment. However the current detection method can'treflect the status of the steering system. Therefore it is necessary for us to make adeeper research on the detective mechanism. Only in this way can we provide thetheoretical base for the detective steering system.When the automobiles turn, ackerman steering guarantee that all of thewheels are doing pure roll. When the ackerman steering has something wrong , itcan not only cause abnormity of wheels abrasion and the increasing of rollingresistance, but also severely influences automobiles' control stability;The steeringgear is the gear down transmission device in the steering system, which influencesautomobiles' many steering capabilities. So it is so necessary that we detect thesteering gear quickly and efficiently. This paper is based on the detection theoryof automobiles' steering machine, conceiving the detection system of theautomobiles' steering machine. The paper can be explored in the followingaspects.1. Analyze on the mechanism of automobiles' steering systemThis paper is based on the theory of automobiles' steering system,researching the important parameters of the steering system (the steering gearangle ratio, the angle ratio of steering angle and wheel angle). The influence onvehicle steering performance of the angle of ackerman steering and parameters ofsteering gear is analyzed in detail.When the automobile is turning, the wheel angle of one side is certain, thesize of the other side depends on the same side's bottom angle of the ackerman.Meanwhile, the angle of the wheel and the same side's bottom angle are in therelationship of inverse proportion. The steering gear's troubles affect the free playof steering wheel mainly. Only in this way can we provide the theoretical base forthe detective steering system.2. The design of automatic detection test-bedThe automatic detection system of automobile steering mechanism is madeup of the Rapid Tester of Automobile Steering Wheel Controlling Force/Angleautomatic detection test-bed and measuring and controlling system. The RapidTester of Automobile Steering Wheel Controlling Force/Angle measures the freeplay of steering wheel and steering wheel angle.This test-bed includes the following four parts: Measure device, Drive device,Clamp device and Aim at wheel automatically device. Measure device can realizethe measure of automobiles front wheel steering angle by photovoltaic coder.Drive device supplies the power that moves the right-left bedplate from the rightto the left by the electromotor. Clamp device have made use of gas box clampstructure. In the course of detection, it can loose the float bedplate. So thedetection goes very well;however, in the beginning and ending, the clamp deviceclamps the float bedplate to guarantee the automobiles drive in or drives out thetrial platform well. Under the condition of having no gas, the clamp can workcompletely. Automatically aim at wheel device use the diffuse reflect electricswitch as detect sensor, gathering sensor signal by industry computer , controllingelectrical machinery, providing the guarantee for automatic detection.3. The software design for measuring and controlling system.Windows XP is the system platform, and Visual C++ 6.0 is the programminglanguage. Some switch signal, like electric switch and displacement switch, isgathered by IPC5375 card and SJKGLB-3 interface board. The industry computergathers the data by RS 232 port. Application software mainly completes detectionprocess controlling, data gathering, data analyzing and making the result ofdetection.4. Trial and date analyzingAfter testing, the detection system detects the vehicle. The detection result isfit to the theory. It can find the hidden trouble by the difference angle fromright/left wheel. Free play of steering wheel can be measured by the Rapid Testerof Automobile Steering Wheel Controlling Force/Angle and Automatic DetectionTest-bed of Automobile Steering Mechanism. In some case we can find the hiddentrouble of the steering gear.The detection system work safely and steadily;the detection course is inreason and the data is credibility. So it can be used in the detection station andsatisfies with needs.