Research On Laser Radar-Application In Vehicle Overruns Detection

The existence of vehicle overrun not only harms the road transportation safety,but also destroys the transportation market which should be healthy and orderly.At present,the commonly used detection methods are mainly manual parking detection or image mode detection.The former has complex procedures and high labor cost,and is vulnerable to weather conditions.The latter has large error and low precision under night working condition.In view of this,this paper proposes an automatic detection scheme of vehicle geometry size beyond limit using single line ladar.The system is based on the principle of flight of time used for distance measurement and time digital converter for time.The system is used to range the objects in the area under the rotation of the trihedral reflector which drive by the rotated brushless DC motor.Then the polar coordinates are obtained with the angle corresponding to each measurement point,and the contour scanning of the objects in the region is finished.Then upload the measured data to the host computer Lab VIEW,and finally draw the outline and save data.In the application of vehicle geometry size out of gauge automatic detection,we can gain the vehicle’s height and width through data comparing and extracting,and judge whether it is beyond the standard of height and width.The system has the characteristics of easy operation,low cost,no parking,large scanning field and high scanning density.The paper is roughly divided into the following 6 parts.a)pulse laser emission module of SPL PL90＿3-75 W b)APD optical detection module c)brushless DC motor control module based on SI9979d)TDC＿GP22 timing module e)system control module based on MCU ATmega32f)Lab VIEW data processing and contour drawingThe final measurement range of 10 M,scanning frequency up to 40 KHz,the scanning range of 0° <120°,angle resolution of 0.45.