Collision-Avoidance Target-Tracking Actuator Command Generation for UAVs

Monitoring moving ground vehicles using vision sensors mounted on Unmanned Aerial Vehicles (UAVs) in a densely populated area with high-rise buildings is a min-max problem. The cost function minimized or maximized by a pursuer or an evader is the integral of the distance between two vehicles over a finite time interval. One of the common approaches to the optimal tracking problem for UAV s is to minimize the cost function in the worst case caused by the evader. Extending the algorithm for one UAV to an algorithm for multiple UAV s requires collision avoidance capability. The cost function degradation to achieve collision avoidance must be minimal. We present an optimal collision avoidance target tracking algorithm combining the tracking command and the collision avoidance command. Finding the optimal combination becomes a line search optimization problem that can be solved with little computation. The resulting algorithm provides acceleration commands that can be directly used in the low-level controller of UAV s. The performance of the algorithm is demonstrated by multiple computer simulations.