Research On Multi-hierarchy Grid Model And Multi-objective Route Planning Algorithm For Off-road Maneuvers

With the development of science and technology,off-road maneuvers are gradually transferred from the military to the civil field,playing a huge role in civil production,rescue,and disaster relief.Its main objective is to study the construction of traffic environment models in the complex field environment and plan the suitable path for traffic objects.In the current research of off-road maneuvering,however,the following problems still exist: the hexagonal grid exhibits a multi-adjacency relationship and high data accuracy.The evaluation and construction of environmental impact factors with hexagonal grid can obtain the traffic environment model with fine description of traffic environment,but it also brings about the problem of increasing the data scale of traffic environment.The influence of data scale on the efficiency of the route planning algorithm is exponential.Therefore,the efficiency of the route planning algorithm in large-scale offroad scenarios is usually very low.The factors affecting the off-road environment are complex.In classic off-road maneuvers,many environmental factors are linearly weighted into one factor for route planning,but more factors affecting the field environment are needed,and the weighted method makes the planned path inconsistent with the real environment.Because of this,the thesis proposes a method for constructing a multi-hierarchy hexagonal grid model for off-road maneuvering.This method effectively resolves the contradiction between the scale of data in the grid model and the accuracy of the environmental description,thereby improving the efficiency of the route planning algorithm.Then,a multi-objective path planning algorithm for off-road maneuvering is proposed.Using this algorithm,the optimal off-road maneuvering route solution set that satisfies various environmental constraints can be planned,and the accurate and efficient application of off-road maneuvering can be realized.The main work and innovation of this thesis are as follows:(1)Create a quantification system for the environmental impact factors of off-road maneuvering: the field environment has complex impact factors,and the premise of offroad maneuvering is a real and effective simulation of the field environment.This thesis fully considers the geological and terrain factors affecting off-road maneuvering and constructs a quantification system for the environmental impact factors of access to more realistically simulate the field environment and provide support for the route planning algorithm.(2)Construction of multi-level hexagonal grid access environment model: To address the contradiction between the scale of access model data and the accuracy of environment portrayal,this thesis makes full use of the idea of spatial reasoning and applies it to the sparse field environment of the road network,designs grid level compression algorithm and neighbor reconstruction algorithm,compresses the redundant grid,and constructs a multi-level hexagonal grid access environment model,without losing model accuracy.The model data scale is reduced,and the efficiency of the route planning algorithm is improved without losing model accuracy.(3)Designing a multi-objective route planning algorithm for off-road maneuvering:Based on the quantification results of environmental factors and the characteristics of the multi-level hexagonal grid access environment model,a heuristic consistency function is constructed for the two target components of grid access capability and slope access capability,and the multi-objective route planning algorithm for off-road maneuvering is finally realized.Comparative experimental analysis was conducted to verify the validity and stability of this study for the environment model and path planning algorithm proposed in this study,respectively.In the part of the traffic environment model,the real environmental data and appropriate parameters are used to construct the model.The experimental analysis is carried out in two aspects the stability of the planned path and the efficiency improvement of the route planning algorithm.The experiment shows that the traffic environment model proposed in this study can effectively reduce the data scale of the traffic environment model based on maintaining the stability and efficiency of the generated path.In the path planning algorithm section,the effectiveness and rationality of the algorithm proposed in this thesis are confirmed by comparing and analyzing the indicators of generated paths based on both the traditional and multi-hierarchy hexagonal grid environment models.Finally,based on the multi-hierarchy hexagonal grid environment model for off-road maneuverability proposed in this article and the multi-objective route planning algorithm,an application of off-road maneuverability with high efficiency and high stability is formed.