Multi-Robot formation control based on improved virtual spring method

Multi-robot system may be difficult to avoid obstacles and maintain formation in the complex environment. This paper proposes a multi-robot formation control algorithm based on the improved virtual spring method. First, the traditional virtual spring model is improved by increasing the dynamic damping coefficient between robots. As a result, robots can achieve stable formation in complex environments. Second, in order to solve the problem of the goals non-reachable with obstacle nearby in the formation process effectively, the repulsive force and traction formula of the traditional virtual spring method are modified, and the obstacle virtual spring model with adjustable damping is established to complete the obstacle avoidance behavior of the robot. In addition, a safe distance switching strategy is designed based on the obstacle virtual spring model so that the robots can switch between Go-to-goal and Avoid-obstacles modes according to the distance from the obstacle. The proposed strategies have addressed the local minima successfully. Finally, the simulation results are presented to verify the effectiveness of the proposed algorithm.