Study On The Laser Detection System Of The Automobile Wheel's Deflection

With the raising of people's living standard, the number of automobilepossessed in our nation is also increasing, which firstly results in the trafficsafety problem, while the technical status of the automobile runningdepartments directly affects the safety of running. Wheel location fault is oneof the higher frequency faults in the automobile running departments, whichcan cause the unusual tyre abrasion, shaking, floating and sideslip of thedirection, which will affect the controlling stability, running safety and tyres'abrasion of the automobile, so wheel detection is one of the importantcontents in the automobile safety detection.The national standards "Safety specifications for power driven vehiclesoperating on roads" prescribe the standard of the wheel's deflection. Thestandard is that if the automobile's total mass isn't larger than 3500 kg thedeflection should not be larger than 5 mm;Motorcycle and portablemotorcycle should not be larger than 3 mm;other motor vehicle should notbe larger than 8 mm.Not only the deflection of wheel could inflect the parameter matching ofthe wheel, but also it can give the worse inflection to the parts of the wheelassembles,such as shaft, hub, kingpin, bolt, and so on . The deflection canmake the components easier to fatigue. And it can make the assembleprecision and longevity depress. Then the rotation state of wheels must beworse, even could make flaw the parts of wheels and cause the accident orthe loss of life and wealth.The national standards prescribe that automobile detection departmentshould carry out the detection for the projects such as engine power and theodometer of vehicle. On the cylinder stand such as tester of speed anddynamometer the test-speed is often at 40km/h or more, and the state mustbe hold for a stretch. The driver of front-wheel driven cars couldn't control thedirection of the car, because the front wheel can not only drive but also steeroff. In the stretch, the racing state of automobile is not stable, because of thecylinder stand's characteristic. The instability of the car is easy to lead to aaccident that the car runs out of the stand. And the accident intimidates thelife of the people and the wealth of the department. So the study on theequipment to avoid the run-out accident is necessary and important.Many of the detection departments reject the items of front-wheel drivencars. It is very wrong because the test items in the high-speed are theimportant factor to judge the capability of the cars. The result is the base ofthe insurance, compensate, quality detection, grade of the using automobiles,and so on. Ignorance of these items must arouse the inflection to thedetection departments. People will not be trust to the result of the detection.The impartiality and the authority would depress.The paper's purpose is to design an automatic system to detect thedeflection of the automobile. And design an equipment to avoid thepossibility of run-out tester. This paper can fill the blank of the detection of theautomobile.It's different between the state that the Automobile run on the road andthe state that the Automobile run on the roller .The paper assay thedifference, and study on the dynamics characteristic of the two kinds of thestates. The result of the assaying is the base of designing the detection.Then the paper assays the origin of the wheels' deflection and the keys ondesigning the roller tester.This paper designs the configuration of the detection. The configurationincludes four parts: the part of detecting the deflection, the gearing part, thepart of avoiding transverse swing and the roller drag part. The part ofdetecting the deflection use photoelectricity-coder to measure the length ofthe deflection. The part of the avoiding transverse-swing could use thecharacteristic that the oriented block can Since the lock in the Guide toClamp the wheels and not to become flexible.According to the structure characteristic and the demand controlled ofthis detection, the paper designs the Corresponding system of the signalgathers and controlling. The system can Real-time gather the signal. Thispaper also uses the One-chip computer to deal with the signal. Then the datawould convey to the computer with bunch. The computer would analyze thedata and output the result. In the factor of electric control, this paper uses thelow-voltage electric apparatus to carry on the control to the hardwareequipment. The system realize to whole time sequence and control ofsystem by computer. In the end, this paper introduces the design of circuit'santi-interference. It includes the interference protection measures of directelectric power, signal inspection and signal transmission.In the following, this paper describes the software realization ofintegration inspection system, which is the very key to the system. Thesoftware system includes the operation platform and application program. Inthis paper, Windows98 is been selected as the operation platform. In theapplication program, Visual C++6.0 is the programming language. Theapplication program includes many modules. They are system self-testingmodule, automatic testing module, network communication module, printingresult module and helping module, etc. In these modules, automatic testingmodule is a very important one, which is comprised by the module of readingthe status of photoelectric, guiding message module and collecting datamodule, etc.In order to realize the on-line inspection, this paper uses the networkcommunication technology-Csock class, which is supplied by Microsoft.There are many good function in this class that make networkcommunication becomes simple.In the end, the integration inspection system is proved excellent bypractical experiments.