Research And Development Of A Portable Road Friction Coefficient Tester

Road friction coefficient is one of the most important parameters in the road traffic accidents, which has much attention of people. In order to facilitate the road friction coefficient measurement, MFDD is obtained by analyzing the deceleration variation. Use the relationship between road friction coefficient and braking deceleration to develop a portable tester for measuring coefficient of friction road surface friction coefficient.The hardware of a friction coefficient acquisition system is developed by choosing ATmegal6L microcontroller, MMA7260QT accelerometer, LCD and independent keys, mainly including data acquisition module, display module and key control module. This system can not only output the road friction coefficient, calculate the average acceleration of the vehicle, but also display the real-time acceleration.After completing the hardware, the design of system software is finished, including PC data processing procedure and ATmegal6L microcontroller procedure. PC communications procedure with VC++ 6.0 programming accomplishes data reception, data retention, data display and so on. Through ICCAVR developing platform and AVR STUDIO, we can first write the programs and then download them into the microcontroller to accomplish what functions should be. The programs include data acquisition procedure, data display procedure and the control procedure of the keys.Based on the preliminary work, we also did braking experiment on the bituminous pavement with the system designed in this dissertation and accelerometer and multi-channel data acquisition system. The experiment results suggest the system designed accomplishes basic function testing road friction coefficient.