Research On Non-contact Multi-wavelength Road Condition Detection System

With the rapid growth of my country’s national economy,transportation plays an important role in social production,life and economy,and transportation will be severely affected by the harsh road conditions.Therefore,the development of a set of road condition recognition equipment is very important.At present,domestic research on road surface condition monitoring is not mature enough,and imported equipment is expensive and cannot be widely used.In this paper,a non-contact mid-infrared reflective measurement system is used to identify and detect the road surface.It is designed to provide traffic management department with road condition information,so that road cleaning and maintenance work will become convenient and intelligent.First,carry out basic theoretical research on road surface condition measurement based on infrared reflection method.According to the spectral refractive index,spectral reflectance and spectral absorptance characteristics of infrared light on ice,snow,water and asphalt pavement,select the appropriate wavelength infrared wavelength laser With the detector,combined with the absorption-based multi-band active light source measurement principle,three wavelengths of infrared light are selected to enter the road to be tested,and the reflected light intensity of the road to be tested will be different.According to the characteristic quantities such as the ratio of the photoelectric signal reflected by the three-wavelength laser,the threshold range of each road surface state is obtained,and the four road conditions of ice,snow,water and asphalt are recognized.According to the thickness of different road coverings and the characteristics of the reflected light intensity,the thickness of the road coverings is judged and the thickness estimation result is obtained.Secondly,a road state detection hardware system is designed according to the actual requirements of road state detection.The hardware system includes the optical path system,control module,signal processing circuit and transfer station.The optical path system is designed with a reflective optical system to ensure the integrity of the optical path,reduce external light interference and reduce loss;the control module is responsible for time-sharing control of the three-wavelength laser signal;the signal processing circuit is mainly responsible for the weak electrical signal output by the detector For extraction and acquisition,the system uses phase-locked amplification technology to extract weak electrical signals,and the data acquisition card implements A/D conversion;the transfer station uses the embedded industrial control board PC104 to be responsible for the data reception and remote communication of the host computer.Finally,the software design,system calibration and testing of the road condition detection system are carried out.The system calibration procedure and the final measurement procedure are designed to be responsible for the system signal acquisition,calculation and remote communication;the system calibration is to formulate an identification and calculation standard for measuring the state and thickness of the road surface through a large number of experiments;in order to verify the stability and accuracy of the system,The actual road surface is tested,the optical path,circuit and wireless communication are operating normally,and the design has reached the expected goal,and it can distinguish and display the thickness of ice,snow,water and asphalt roads.