| Mobile robots have the advantages of flexible movement and strong environmental adaptability,and have been widely used in indoor environments such as home,service and logistics warehouses.However,faced with the complexity and uncertainty of the task environment,a single robot has limitations such as load,endurance and function,so multi-mobile robot cooperative system has become one of the development trends of mobile robot applications.Formation obstacle avoidance control is one of the key technologies to realize indoor mobile robot cooperation.This paper carries out research on this method,and the main research contents are as follows :(1)In view of the requirements of f ormation maintenance and obstacle avoidance when multi-robots perform tasks,a formation control method considering obstacle avoidance is proposed under the framework of centralized cooperative control.Firstly,a leader-follower formation control model is established,the formation control problem is transformed into a trajectory tracking problem,and the formation control is realized based on model prediction.Then,an artificial potential field method is introduced to avoid obstacles by repulsive force,and a formation obstacle avoidance controller is constructed considering velocity and acceleration constraints.Simulation and physical test results show that the designed obstacle avoidance controller can effectively avoid the obstacles detected in the pr ocess of moving while realizing formation and formation maintenance.(2)Aiming at the condition that the multi-robot system only interacts with local information,a distributed formation obstacle avoidance controller based on consistency is proposed.The communication topology of multi-mobile robots is analyzed by graph theory and matrix theory,and a distributed formation controller is proposed based on consistency theory.Then,considering the obstacles in the real environment,the distributed formation obstacle avoidance controller is constructed by introducing artificial potential field to realize the obstacle avoidance of mobile robots.Finally,the stability and effectiveness of the controller are verified by simulation test.(3)In the face of comple x obstacle environment,multi-robot formation may need to detour,resulting in reduced task efficiency,or even no path.In this paper,a formation path planning algorithm considering formation transformation is proposed.Firstly,the obstacle is expanded twice according to the space occupied by individuals and formations,and the configuration space containing hard and soft obstacles is constructed.Under the hybrid A*framework,the weighted cost function is constructed considering the way the formation passes through soft obstacles.Simulation and experimental results show that the algorithm can change the length of formation transformation path by adjusting the weight parameters under the condition of obtaining feasible formation path,and meet the requi rements of different tasks. |
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