Cooperative Constrained Enclosing Control of Multirobot Systems in Obstacle Environments

This paper develops a novel cooperative constrained control framework to solve the moving-target enclosing problem for multirobot systems, where safe navigation and formation precision are concerned in obstacle environments. When moving obstacles block the encircling motion, the enclosing formation contracts towards the target with a precise spacing pattern. Without a priori knowledge of environment information, the mobile robot group can track and enclose a moving target while guaranteeing limited sensing requirements and collision avoidance with the target, neighbouring robots, and obstacles. Under the precision constraint, with an encircling speed assigned to only one robot, the mobile robots are driven by their neighbours until all robots enclose the target as a whole. With the help of velocity observers, the robot group can converge to a small neighborhood of the desired enclosing formation without knowing the target's velocity. Simulation results demonstrate the effectiveness of the proposed constrained control strategy.