Aircraft Route Planning Under Guidance Relayed By Multiple Ground Stations

The aircraft guidance relayed by multiple ground stations is a cooperative guidance method which relies on multiple ground stations to guide the aircraft in sequence.The ground stations are scattered in different spatial location and the guidance sphere can cover a large area.The guidance not only has high reliability but also can effectively extend the controlled flight range of aircrafts such as missiles and unmanned aerial vehicles.The problem of aircraft route planning under guidance relayed by multiple ground stations is a key issue to realize the prospective and advanced guidance.In this paper,the problem of aircraft route planning under guidance relayed by multi-stations mainly concerns how to plan a path for the aircraft that satisfies various guidance constraints and makes the aircraft quickly arrive at the target point by following the guidance relayed by multi-stations.Firstly,this paper analyzes the key elements and multi-constraints of route planning under guidance relayed by multi-stations.The considered key elements include ground stations,guidance handover,guidance combination selection,aircraft and target.Constraints include the guidance sphere constraint,the constraint of the length of the path in guidance handover area(guidance handover constraint),the meeting time constraint,the maximal corner constraint,and the curvature constraint.The guidance handover constraint distinguishes the problem of aircraft route planning in this paper from other route planning problem and is a main source of the difficulty of the problem.Secondly,this paper introduces the common issue and the optimization method for route planning under guidance relayed by multi-stations.The selection of guidance combinations from multi-stations is a common issue of the route planning in this paper.When there are a variety of guidance combinations for the same target,this paper puts forward a method to select the best guidance combination,which lays a foundation for further route planning.This paper uses the differential evolution as the optimization algorithm of route planning problem,since the route planning under guidance relayed by multi-stations is a continuous valued optimization problem,and differential evolution algorithm is not only easy to implement but also has strong global searching ability in continuous problems.The paper also establishes a basic framework for the route planning based on the differential evolution algorithm.Thirdly,when the aircraft turning radius is far less than the guidance radius of ground stations and the curvature constraint can be ignored,this paper studies the route planning for static target and moving target respectively.According to the characteristics of the route planning,this paper puts forward an angular coding method for waypoints,and the angle(one variable)can replace the coordinate(two variables)to express the waypoint position through the method.It can also compress the search space,and make it easier to express the aircraft path and handle the constraints.The route planning regareding static target contains two aspects: considering or not considering the maximal corner constraint.The route planning regareding moving target is a method that calculates the difference of time when the aircraft and the target move to the same destination,and then judges whether it meets the time constraint,and transfers the moving targets to static target at last.Finally,when the aircraft turning radius is not far less than the guidance radius of ground stations and the curvature constraint cannot be ignored,this paper puts forward the route planning method based on the Dubins paths.The waypoints position vectors are optimized by the differential evolution and the headings are generated randomly,which can reduce the dimension of differential evolution operations,avoid the excessive amount of calculation and save the time cost.When the guidance handover constraint is difficult to satisfy,the route planning method based on the Dubins path doesnot work well.By investigating the longest paths in guidance handover area,this paper digs up the prior knowledge on longest path pattern and puts forward the Dubins route planning method based on the longest path pattern in guidance handover area.Comparative experiments demonstrate that the Dubins route planning method based on the longest path pattern in guidance handover area is better than the route planning method based on the Dubins path when the guidance handover constraint is difficult to satisfy.Based on the research above,this paper provides a feasible solution for the problem of aircraft route planning under guidance relayed by multiple ground stations.