The Research And Realization Of The Vehicle Trace Display System Based On The Ultrasonic Location

Nowadays, in order to improve the efficiency, more and more test fields use the electronic assistant in the test of driver qualification. Different with the inferred equipment widely used at the present day, the ultrasonic location is applied to the vehicle trace display the first time in this paper and a set of vehicle trace display system is designed and realized. According to the theory of triple-point location, the system can locate the vehicle in the field by the transmission and receive of the ultrasonic pulse signal and display its trace on the screen, which makes the test result more intuitionistic and clearly.The structure of the system is introduced first in the paper. Then the design and realize of the hardware and software are illustrated in detail.The MCU controls the signal transmission and receive. Because it is important to know the sequence of the received signals, they are controlled by the same MCU and thereby the consistence of the time benchmark is guaranteed. By using the D-trigger, three signals will not lose and can be handled one by one. Because of the separation of the interruption handle and data transmission, the time of the interruption handle is reduced, thus the real-time property is improved.The system only needs to acquire the time when the ultrasonic signal is received and transmit it to the computer through the serial port to work out the location equations,. The algorithm is based on the distance formula of two points on the plane, and the location equations can be simplified to a linear quadratic equation so that the solving progress is rapid. As a result of the above characteristic, the hardware and software design are greatly simplified. Every part has been tested and amended many times and the location result is satisfied.In the end, the conclusion is made and the future application is prospected.