Research On Vehicle Anterior Shape Measurement Technology Based On Lidar

When the vehicle is driving on uneven roads,the speed is often low,mainly due to the fluctuation of the vehicle's center of mass during driving.Therefore,the driving speed of the vehicle under the uneven road surface is improved.The key point is to adjust the movement posture of the vehicle according to the road surface in real time during driving,so that the center of mass can reach the basic straight line.With the development of active suspension technology,the stability of the vehicle's center of mass can be maintained by controlling the active suspension.This paper combines the national key research and development plan "High-mobility emergency rescue vehicles(including fire-fighting vehicles)dedicated chassis and suspension key technology research"(project number: 2016YFC0802902),using laser radar,inertial navigation and GPS and measuring the elevation of the road front The main research work of the thesis is as follows.Firstly,the design principle of the digital ground experimental platform is expounded,and the experimental platform is built according to the design principle.The experimental platform is based on laser radar,inertial navigation and GPS.The test principle and measurement index of each sensor are introduced.According to the requirements of the project,the economical and reasonable sensor is selected under the requirement of the test accuracy.Secondly,the accelerometer and gyroscope data in the inertial navigator are used to correctly represent the attitude of the vehicle.The quaternion method is selected in the cosine method,Euler angle and quaternion of the three methods of attitude calculation..According to the quaternion theory,the quaternion is continuously updated during the fixed time period of the attitude calculation using the accelerometer and gyroscope data.After spectrum analysis of the static and dynamic characteristics of accelerometers and gyroscopes,a second-order complementary filtering method is used to integrate sensor data,which greatly improves the speed of attitude settlement.Furthermore,based on the accurate representation of the vehicle's attitude,the coordinates of the multi-sensor are integrated by the laser radar,the inertial navigation system,and the GPS.The transformation of the point cloud from the lidar coordinates to the vehicle carrier coordinates to the WGS-84 coordinate system is realized.The coordinate coordinates of the multi-frame acquisition can be uniformly embedded into the WGS-84 coordinate system for the construction of the digital ground.is crucial.Finally,the GPS phase center is used as the coordinate system origin to establish the coordinate system.The steering trajectory of the vehicle is derived according to the vehicle body parameters and the steering angle in motion.The steering trajectory equation and the established digital ground point cloud are combined to extract the steering trajectory.The point cloud height of the area,and then the least squares curve fitting of these elevation scatters to obtain the road curve on the steering trajectory,and based on this height,the vehicle's next driving posture is regulated.