Research And Design Of Pavement Sensors In Rain And Snow Conditions

In recent years,the highway mileage is the longest in the world.With extreme changes in global climate,the heavy snowfall happened in the northern area,meanwhile the freezing rain phenomenon happened in the southern area.The complicated weather condition has influence occasionally on highway pavement,which appears waterlogging,snow and ice road condition,causing the traffic accidents much more and the serious loss of people's lives and property.In order to reduce the rainfall and snowfall weather conditions on the influence on highway pavement,we need design related detection device used on highway pavement according to different weather conditions,analyze possible situation and give out early warning,which can promote the highway safety.It has important significance on highway in order to realize informatization and intelligence.In specific to pavement weather condition detection,we traditionally used the method of artificial observation.With the development of electronic and computer network technology,many domestic and overseas enterprises develop functional and reliable testing equipment using micro-sensors,signal acquisition,analysis and processing circuit,which can realize real-time monitor on pavement weather conditions.I have learnt related sensor theory,studied detection methods on pavement weather condition and put forward the design scheme of low cost and high reliability.It can be applied to the highway mass application.In measurement of water thickness in rainy weather,I designed a capacitor sensor with new structure by using the principle of variable area type capacitor,adopting signal conditioning circuit such as the capacitor voltage conversion IC CAV444,amplifier AD623 and first-order filter.It concluded by the experiment that the voltage output of the device has a linear relationship with water depth value by monadic linear regression analysis.We can establish a yuan linear regression equation for forecasting model.The advantage of measureable device application is wide measurement range,good linearity,good repeatability,high precision and low cost.It can reduce the influence of parasitic capacitance on measurement in the environment.In measurement of snow depth in snowy weather,I designed a kind of scheme based on the principle of ultrasonic detection,using the time-difference method for measurement.I adopted signal conditioning circuit such as transmitting circuit module MAX232 and receiving integrated circuit CX20106 A,using signal temperature sensor DS18B20 for temperature compensation.I design timer interrupt service program which based on ATmega328 processor using LCD1602 for experimental data display.According to the scatter and the fitting degree of regression straight line,the experiment concluded that the temperature compensation and the software algorithm can improve the anti-interference ability of sensor detection system through the control group experiment.