Multiple ballistic flight vehicles' launch time planning for collision avoidance based on time constraint set

An algorithm framework is presented to solve multiple ballistic flight vehicles' collision avoidance problem by adjusting their launch time. A collision detection algorithm is proposed in the framework for detecting whether there is flight collision or not in multiple ballistic flight vehicles' cooperative attack, and a launch time constraint set model is built in order to solve the collision avoidance problem. The constraint set is constituted by the launch time interval constraints of the flight vehicles in collision. On the foundation of this time constraint set, an optimization problem which regards multiple ballistic flight vehicles' arriving simultaneously as the optimization goals and includes the expression with the sign of inequality constraints is built, and then the “Big-M” method is improved to transform the problem to standard form of nonlinear programming problem which can be solved by sequential quadratic programming (SQP). The method framework transforms the launch time adjusting problem to an optimization planning problem and has reduced the computational complexity compared with the traditional ergodic launch time planning algorithms. With MATLAB platform, simulations have proved the rationality and effectiveness of the proposed method and the method has high computation efficiency.