Pose Prediction For An Articulated Wheel Loaders Based On Laser Radar

The articulated wheel loader operates in the unstructured ground environment in the field and has the characteristics of variable structure,variable center of mass,variable load,etc.,resulting in poor lateral stability and prone to rollover accidents.Therefore,it’s very important to realize its instability warning and active safety control.The present study does not consider the inadequacy of the key external inducing factors of the overturning of the articulated wheel loader caused by the non-structural terrain resulting in the dramatic attitude changes of the body.so this paper studies the real time acquisition of the unstructured terrain and its influence on the loader body pose.The problem of real-time acquisition of unstructured terrain information and accurate prediction of its pose in the wheel loader operation process has been solved which provides a basis and reference for the instability warning and active control of the articulated wheel loader.The specific research work of the paper is as follows:(1)Build a multi-sensor system based on lidar.Multi-sensor data acquisition in real time based on multi-thread technology,including two-dimentionallaser radar,IMU,and encoder.In addition,the Lagrangian interpolation method is used to interpolate the sensor data with lower sampling frequency,and the data fusion algorithm is used to match and fuse the multi-sensor information.Finally,the experiment verifies the real-time ability and reliability of the system and the three-dimensional virtual visualization of a running loader 1:5 proportional prototype can be realized.(2)Three-dimentional point cloud modeling for unstructured pavement based on two-dimentional lidar.Considering the particularity of the wheel loader’s field work environment,this paper uses a two-dimensional laser radar scanning method to construct a three-dimensional point cloud terrain map,and denoises and optimizes it.At the same time,plotting its power spectral density plots can be used to analyze road surface roughness.(3)The Reasearch on the influence of field unstructured terrain on the change of attitude angle of articulated wheel loader.This paper presents a method for predicting driving pose of articulated wheel loaders.Based on the analysis of the kinematic characteristics and structural characteristics of the articulated wheel loader,the differential driving model is used to predict the position of the wheel during the driving process.The attitude of the loader body is determined through the three-point method.The RMSE of predicted pitch angle and roll angle at the time of 2 seconds in the future is 1.8° and 2.1°,respectively,which verifies the effectiveness of this method.In summary,this paper starts from the acquisition of three-dimensional information of road surface in front of the articulated wheel loader,through the construction of the three-dimensional information of road surface and the current driving condition of the loader,the pose of the body in the future are predicted,which provides the basis and reference for the instability control of the articulated wheel loader.The research contents can provide new research ideas and methods for other vehicles operating on unstructured road in the field.