Path Planning Of Lunar Rover Based On A Star Algorithm And B Spline Function

With the continuous development of science and technology, space activities are increasingly frequent, people’s understanding of the universe in the world is also constantly in-depth. As the nearest neighbor of the earth, the moon is a key position in the world. The development of the lunar exploration can make the comprehensive strength of the country fully demonstrated, and it will help improve the international prestige of the country and the right of discourse in international affairs.At present, countries in the aviation field to seize the commanding height, for a wealth of space resources, put a lot of manpower, material and financial resources to carry out navigation and control research. Not only that, navigation and control in the military, engineering and other aspects are also widely used. Path planning technology is one of the important aspects of navigation and control. It has a very important position in the field of high risk and high danger. At the same time, it is an indispensable part in the establishment of a perfect navigation and control system.In this paper, we discuss the application of A star algorithm and B spline function in the navigation and control of lunar rover. A large number of studies have been carried out in the following aspects:1.A star algorithm is introduced into the path planning of lunar rover, and the path planning based on A star algorithm is formed. The search speed of A star algorithm is very fast, and it can quickly find the shortest path, and its search scale can be easily controlled in order to prevent the blockage. The concrete steps are: firstly, the environment which is static and completely known is converted to a grid map. Then, A star algorithm is optimized and the shortest path is searched.2.In the trajectory planning, using the improved B spline function, the algorithm of the control point, the algorithm of processing multiple knot, the pursuit algorithm, the algorithm of calculating B spline interpolation points are realized. In the end, the Visual C++ language is used to compile the uniform non periodic three B spline function of the value point. The map and path are displayed by GDI mapping technology, so that the lunar rover can move along the path of the two order continuous obstacle avoidance path.3. A path planning and trajectory planning technique for combining A star algorithm with B spline function is explored.The technology has the advantages of A star algorithm, the search speed and B spline curve fitting, and the track smoothness, which meet the requirements of the lunar rover for real time and practical. Proven to be a good solution to the problem of path planning for lunar rover in the static known environment.The innovation of this paper is mainly in the following aspects:1.The search strategy of A star algorithm is optimized. In the same case of F-measure, the grid has the priority to be extended, which is recently added to the OPEN table. By that, it can improve the search efficiency and improve the real-time performance of A star algorithm.2.Improved B spline function. The number of points located in a straight line is omitted from the intermediate point. By comparison, it can be seen that before the improvement, the lunar rover needs to change direction, and after the improvement, the lunar rover maintains the continuity of the speed and acceleration. B spline curve is more reasonable and more practical.3.In the introduction of the advantages and disadvantages of a large number of global path planning, local path planning and trajectory planning method, the creative combination of A star algorithm and B spline function. Not only a quick search of the shortest path, but also to meet the dynamics and kinematics of the lunar rover.