Improved A*-Based Motion Planning for Fixed-Wing UAV with Arrival Time Constraints

Fixed-wing UAV is widely used in military field because of its excellent performance. In the task of suppressing enemy air defense, UAVs need to reach the attack positions at the same time or go to the attack positions in turn to scout or attack enemy ground targets. In order to make UAV complete this task with high quality, UAV motion planning needs to consider kinematic constraints and time constraints, and also needs to ensure accuracy, that is, to ensure that UAV reaches the attack position at the specified time and attack heading angle without error. However, due to the discreteness of time and space in the path search process, the trajectory generated by the traditional motion planning algorithm based on graph search is difficult to meet this requirements. Therefore, this paper proposes an improved A*-based motion planning algorithm. In the front-end path planning, the evaluation function and termination condition are designed to meet the task requirements, and the time reallocation is used in the back-end trajectory optimization. Through the cooperation of path planning and trajectory optimization, the time-space error is eliminated. According to the analysis of simulation experiments, the trajectory solved by this algorithm can meet the task requirements. And compared with the traditional A*-based motion planning algorithm, it reduces the time consumption of trajectory solving.