用于塔群防碰撞分析，将三维空间内的运动转化为二维平面问题，判断塔吊是否可能发生碰撞。同时给出一套相应的避让策略。-Tower and prevention for crash analysis, the movement into three-dimensional space within the two-dimensional problem, determine whether the crane collision may occur. And gives a corresponding set of avoidance strategies.