The Research About The Measurement Instrument For The Friction Coefficient Of Wheel Pavement

The friction coefficient of pavement is an important technical parameter. It does not only decide the road traffic capacity, but also affects the traffic safety. With the rapid development of the road transportation, the current equipment of friction coefficient of pavements works on the condition of breaking off the traffic and it works slowly with low efficiency. According to the needs of society and supporting on the practical test. A new equipment of the friction coefficient of pavement was developed.The common methods of the friction coefficient of pavement are introduced briefly in the papers. And it analyzes the relationship between the slip ratio and the friction coefficient of pavement. In addition, it deduces the relationship between the friction coefficient of pavement and the friction frice of the road. On the basis, it ascertains the structure of the equipment of the friction coefficient of pavement and propels a method by collecting the wheel signal as well as calculating the real-time slip under the control of the slip rate of target area. Finally the design proposal of the system was provided.In the hardware design, the circuit diagram and printed circuit board of the system's electronic control unit were completed by selection of the STC89C52 as microprocessor of the system. It consists of six modules: the MCU minimum system, the A/D conversion circuit, the wheel-signal modulate circuit, switch output circuit, serial communication interface circuit and the power circuit.On the basis of the hardware design, finishes the software design of the system's software, including the MCU control program of the slave-computer and the application program of the host-computer. The slave-computer's software uses C51 assembly language and its action is parameter setting, data receiving and displaying and report printing. The host-computer's software uses VC++ assembly language and its action is signal picking-up, data calculating and transporting.The paper also tests the functional of the system after debugging the whole system. The testing result indicates that the system can work in the normal traffic flow and it is easy to operate with high efficiency and accurate measured data. So, completes the development task and realizes all prearranged function successfully.