Research On Establishment Method Of Digital Elevation Model For Vehicle Front Terrain

Emergency rescue vehicles have high requirements for ride comfort due to their specific uses.Suspension system,as a key component to transmit road excitation,has an important impact on vehicle ride comfort.By establishing the digital elevation model of the terrain in front of the vehicle,the elevation information of the wheel passing through the road can be obtained in advance,and then the suspension system can be adjusted to attenuate the vibration from the road surface,so that the emergency rescue equipment can reach the destination safely and efficiently.In this paper,combined with the national key research and development project "Research on special chassis and suspension technology for high-mobility emergency rescue vehicles(including fire-fighting vehicles)"(project number: 2016YFC0802902),according to the concept of preview active suspension,the original point cloud data are processed by lidar,and the digital elevation model of vehicle front terrain is constructed.In order to extract elevation information for suspension system.The main work of this paper is as follows:On the basis of reading a large number of documents about road surface detection and three-dimensional reconstruction,this paper analyses the road surface terrain detection methods used in vehicle,and studies three widely used modeling methods for digital elevation model construction,and chooses appropriate road surface detection technology and modeling methods.Design the whole vehicle front terrain data acquisition system.This paper introduces the application background and working principle of lidar,chooses the suitable type of lidar,determines the installation position and angle of lidar on this basis,completes the design of multi-sensor fusion scheme combining inertial measurement unit and GPS,and corrects the measurement result of lidar by zeropoint.Data processing of point cloud.Combining the initial radar point cloud data with several coordinate systems,coordinate transformation is carried out in MATLAB.After data fusion,the three-dimensional coordinate information of the road point cloud in the available terrestrial coordinate system is obtained.Then,the topological relationship between the points cloud is constructed by KD-tree for the discrete point cloud data.Because of the existence of measurement noise in the process of data acquisition,the noise points in point cloud data are removed by statistical filter.The improved Delaunay triangulation algorithm completes the establishment of digital elevation model.The three existing Delaunay triangulation algorithm modeling process is completed.Based on this,the Delaunay triangulation algorithm is improved according to project requirements,and the digital elevation model is established.The model effectively reduces the impact of flat terrain data and improves the efficiency of model utilization.According to the preset wheel trajectory,the elevation information of point cloud is extracted from the model,and the fitting process of point cloud elevation information is completed by using RBF fitting algorithm.The validity of the digital elevation model is verified.