Research On The Piezoelectric Detection Method Of The Vehicle Wheelbase Based On Tires Western

With the continuous development of the automobile industry, automobile as a modern means of transportation, plays an increasingly important role in the social production and daily life of the people. However, in the process of car using, its technical condition and performance will continue to deteriorate because of vehicle structure and external conditions, with the increase in automobile mileage and an extension of using time. So the performance of vehicles requires to be detected occasionally and timely by using modern means of automobile testing and detect and diagnose technical conditions of vehicles. Judging the status of the vehicles and taking corresponding countermeasures can greatly improve the reliability of the use of motor vehicles, can give full performance of motor vehicles, improve the rate of motor vehicle in good condition, extend the service life of motor vehicles and get greater economic benefits.Because of the frame and axle deformation or a rocky ledge, as well as the bolt loosening, axle connection site happen to wear and other reasons, it will form a certain amount of automobile DAD in running. When the difference exceeds a certain limit, it will affect the performance of motor vehicles. Automobile DAD performance has a significant impact to the car, for instance, vehicle driving stability will deteriorate, easily lead to the overall vehicle sideslip when braking and speeding up, and cause traffic accidents. When it is on straight line motion, the automobile width account for road will increase and affect traffic safety, as well as causing a significant increase in tire wear, economic losses and potentially dangerous. They should not be ignored. Therefore, it is great significance of actively detecting the automobile DAD.At present, there are two traditional detection methods, such as photosensitive detection and laser detection. Photosensitive detection of automobile DAD detect wheel axis centre by using reseau structure, and applies a theory of relatively measuring to get the test result of automobile DAD. Photosensitive reseau structure is composed of photosensitive tubes array, so it is apt to be affected by external factors, limited by mechanical machining technique. And the testing accuracy of this detection method needs to be improved. Laser detection of automobile DAD is difficult to realize the accurate location between transmitter and acceptor and ensure the light intensity for radiation of light and interference among beams of light. Therefore, it needs an improved method which is simple to operate, has little external interference and more accurate detection result. It also meet the need of detection of automobile DAD. Automobile DAD detection based on piezoelectric cable is designed for above reason.The piezoelectric cable is applied to automobile DAD detection as sensor. Its overall design is composed of eight piezoelectric cables and four trapezoidal steel plates. The car DAD of a straight line moving can be get through voltage signal that the piezoelectric cable sensor under the left and right steel plates outputs. The car horizontal offset can be detected though voltage signals which from the piezoelectric sensor of before and after testing plates when the car is moving at curve. The main thesis of the study include the following: And amend error arising when the car is moving in the curve, so that it improves the accuracy of the detection.In this paper, the study includes the following:(1) State the detection principle of the existing detection method of automobile DAD and analyze the advantages and disadvantages of various detection methods. Based on the disadvantages, put forward the piezoelectric detection methods of the vehicle wheelbase based on tires western. That is using the piezoelectric cable as sensor to detect the vehicle wheelbase.(2) Discusses the properties and working principle of the piezoelectric cables as well as its advantages when it works as sensor in the cable as in the automobile DAD detection. The piezoelectric cable is greatly significant for the automobile DAD detection. Design the program how realize tire piezoelectric blot detection method, including the error compensation method mainly caused by closed curves, the automobile DAD implementation in straight line running and the realization method of real-time speed.(3) Established mathematical model of the vehicle wheelbase detection. There will inevitably be the left or the right of the curve or the state of traffic in the vehicle wheelbase detection process, so it is necessary to establish the mathematical model of error compensation when the car is turning. in order to reduce or eliminate errors caused by turning. The vehicle horizontal displacement can be get in the process of testing though designing detection plate as the dual-trapezoidal structure. Then get radius curve when the vehicle is turning. At last amend the final test results.(4) Design and select the hardware and software of the vehicle wheelbase detection system. Design specific table size and installation location of detection plate. The error of the test results caused by auto curve moving can be detected through detection devices Introduced signal conditioning and the basis of principle of signal collection equipment as well as chosen reason. Then it marked out the detection of flow chart of the entire detection system.(5) Study on the piezoelectric tire wheelbase blot detection method on the Jetta. Analyzed the collected data, compared the test results from photosensitive method with from piezoelectric method. It showed that the device has high accuracy and good stability, and verified the detection device can accurately detect the center wheel by detecting the location of devices. Finally, analyze errors, in order to provide the basis of error for reducing or avoiding error in the next step.The automotive detection system this article developed can detect automotive DAD quickly and effectively and accurately. It improves the traditional automotive DAD detection, reduces the impact from the vehicle itself and other various factors to the detection system and improves the efficiency and accuracy of detection. Highly modular design of the detection system can make the system have a higher equipment reliability and maintainability. Detecting and recuperating vehicles by using this detection system can guarantee that the vehicles have the best handling and stability. It can ensure traffic safety, reduce traffic accidents, and can greatly reduce abnormal tire wear, reduce vehicle user's economic losses, as well as it is very favorable to the society's economic development.