Research On Indentifying The Linear Parameters Of Road Based On GPS/INS System

The road is the carrier of the vehicle. The performance of linear parameters directly affects vehicle traffic safety. The vehicle rollover model illustrates the influence of road alignment parameters on vehicle safety and stability. Therefore, in order to study the influence of the road alignment parameters on the vehicle stability, it is needed to obtain the vehicle turning radius, the road slope value and so on.According to the road design drawings to obtain the road alignment parameters for the construction of a long time, there is a large error in the road.This paper presents a multi parameter algorithm to obtain the linear parameters of the road curve based on the vehicle speed, direction, trajectory and attitude which Car-GPS/INS collected.In order to obtain more accurate raw data Aiming at the problem of signal loss in common vehicle GPS equipmen. The application of GPS/INS equipment in the process of vehicle driving speed, direction, trajectory and attitude parameters is put forward.The noise frequency of the data collected in different levels of road surface is not the same. Therefore, it is needed to determine the cut-off frequency of the conventional low-pass filtering method can not meet the requirements of the data denoising in this paper. Because the wavelet analysis can be used to deal with the signal, different time windows and frequency windows can be used in different frequency, and the different frequency components can be decomposed into different frequency bands. Therefore the introduction of wavelet analysis method for denoising the data, which is proved by examples of wavelet denoising feasibility and superiority.After the completion of data denoising, the paper presents a multi parameter extraction algorithm of linear parameters. In the extraction algorithm of linear parameters of road curve, the heading is applied to the judgment of the turning point of the road track. According to the heading to determine the path of the inflection point of the trajectory of the curve, and then according to the curve to be combined to extract the linear parameters of road curve. This paper discusses the advantages and disadvantages of the method for extracting linear parameter of road longitudinal curve. A method is proposed to obtain high accuracy of road slope angle by using the angle of vehicle speed in NED coordinate. Then considering the trend of the GPS/INS collection and the trend of the change of the actual height is same,so the elevation of GPS/INS collected is used to determine the slope of the curve of the road. Finally, an algorithm to extract the linear parameters of the longitudinal curve of the road is proposed.At the end of this paper, the MATLAB/VC++ mixed programming is used to build the linear parameter extraction system.Then using example verified the feasibility of the program.