Design Of Vehicle-mounted Road Roughness Measurement System Based On ARM

The road roughness is one of the most important indexes of performance for appraising highway and city road and inspecting road construction,directly reflects the comfortable of the vehicles,the security of road and the use of the state, providing an important reference for road repair, maintenance and renovation. Therefore, how to quickly and easily measures the flatness of the road has become an issue of practical significance. With the rapid development of embedded technology and sensor technology, the method of non-contact detection gathering the road roughness has become the trend of the area. Therefore, this combination of laser displacement sensor and an acceleration sensor designs and develops an Pavement Roughness acquisition system based on ARM.The pavement roughness detection system constructed in this paper is based on a laser displacement sensors, acceleration sensors and rotary encoders. According to the feasibility of the base system on the overall program,the transmission card based on Freescale ARM Cortex-M4 core microprocessor MK60DN512ZVLQ10 and the capture about sensor based on C8051F040 microcontroller is designed.Based on the research of the CAN protocol and TCP/IP protocol features and implementation of the principles, an efficient embedded CAN-Ethernet gateway is designed, porting the real-time operating system uC/OS-II, achieving the acquisition and transmission of multi-sensor data, and then combined with C #.NET to design PC interface system, formulating a host computer and lower computer communication protocol based on CAN data frame format, finally the test data collected by system was fit and filtered, according to the vertical acceleration by integrating twice,we can get the vehicle body vibration displacement,surface elevation measured with a laser sensor subtract displacement while measured with a acceleration to obtain the actual elevation of the road. Pavement characteristics analysis based on elevation signals. Test results show that reasonable designed pavement roughness detection system, feasible, and has good practical value.The main completed contents of this article include:Firstly, developed a set of lower machine of data acquisition card based on C8051F040;Secondly, developed a set of lower machine of CAN-Ethernet gateway freescale based on K60;Thirdly, developed a set of PC data acquisition system for the lower machine based on.NET;Finally,test the raw data and the results of the analysis denoising, based on International Roughness Index road to determine the level of surface flatness, and verify that the system measurements.