Research Of Pavement Roughness Based On Laser Ranging And Noise Reduction Technology

As an important target in the road evaluation and the road maintaince, the pavement roughness is an important factor which effects vehicle comfort and safety. The method of pavement detection based on laser ranging and noise reduction technology is researched and realized in this paper. The system utilizes International Roughness Index (IRI) as the parameter of pavement roughness measurement evaluation. According to the calculation of international roughness index, the mathematical model applied to the detection system is established. Then the interface between the devices is analyzed in the detection process. The computer is the key of the measurement system hardware which also includes laser range scanner and gyroscope. The laser range scanner is used to measure the vertical height to the road surface, while gyroscope is used to measure the vertical acceleration of laser range scanner, which caused by the turbulence in the process of moving. Based on the raw data collected, rational mathematical model used to calculate surface elevation is created.Meanwhile, the system software taking Visual Basic 6.0 as its development environment, designs visual interface of data communications and data acquisition. By analyzing the characteristics of vehicle vibration signals, an appropriate filtering algorithm of Butterworth low-pass digital filter is researched and selected. Compared with the current filtering methods, Butterworth low-pass digital filter is designing convenient, economical and practical. Using MATLAB software, the digital filter is designed and made simulation, which is used in the actual road test. Then the original vertical vibration signal collected by gyroscope is filtered for noise reduction. International Roughness Index of the test road could be obtained through numerical method.Finally the pavement roughness measurement system based on laser ranging developed by this paper has been used in the detection of the actual road. Through a large number of repeated experiments, IRI values of the test road are obtained. The experimental result indicated, this detection method and the filter designed is reasonable and feasible. The paper lays the foundation for utilizing research results in non-dedicated test vehicles.