Research On Finite-Time Formation Control Of Multiple Mobile Robots Based On Model Predictive Control

With the continuous development of robot technology and artificial intelligence technology,the intelligent degree of mobile robot is getting higher and higher,which has provided convenience for people in various fields.However,for some complex tasks,limited by carrying capacity and perception,a single robot is often not competent.Due to the higher redundancy,robustness and stronger perception ability of multi-robot system,it is often used to complete a wider range of complex tasks.Cooperative formation of multi-mobile robot system provides cooperative ability for multi-robot system,which is a hot research direction in the field of robot.Unlike industrial robots,mobile robot systems usually work in unstructured environments.In actual operation,it is necessary to complete the construction of the environment map and the functions of autonomous navigation and obstacle avoidance.In addition,the mobile robot itself is also limited by physical constraints such as speed,acceleration and torque.Therefore,the influence of these constraints needs to be fully considered when designing the mobile robot controller.As we all know,model predictive control(MPC)is an effective robust control method that can handle various constraints.However,in the optimization solution,the real-time performance is often not guaranteed.In this paper,MPC method and finite-time theory are deeply studied,and the combination of the two is used to improve the effectiveness and ability to deal with constraints of multi-mobile robot formation control.The main research contents of this paper can be summarized as follows:Firstly,the point stabilization problem of a single mobile robot is studied.Aiming at the problems of strong nonlinearity,various physical constraints and difficult to guarantee the real-time performance of mobile robot system,an MPC method based on finite time stability theory is proposed.The point stabilization problem of mobile robots is transformed into MPC problem,and a continuous / generalized minimum residual method based on finite-time stability theory is proposed to optimize the control variables to achieve point stabilization control.Secondly,the trajectory tracking problem of a single mobile robot is studied.Aiming at the problem that the torque layer of typical commercial robots is not open,the trajectory tracking control of mobile robots is considered under the Acceleration-Level Pseudo-Dynamic Control(ALPDC)framework.The constrained trajectory tracking problem is transformed into a MPC problem,and the same method is used to solve the optimization problem to complete the trajectory tracking task.Thirdly,the formation control problem of multiple mobile robots is studied.Aiming at the formation control problem of multiple mobile robots,the leader-follower formation framework is used to design the controller.Firstly,a finite-time distributed observer is designed based on the communication topology to estimate the state information of the leader robot.Then,a distributed finite-time MPC control strategy is designed according to the tracking error model and various constraints to realize the formation control task of multiple mobile robots.Fourthly,the control problem of mobile robot under the influence of noise is studied.Aiming at the influence of noise on the pose information measured by mobile robot,a moving horizon estimation(MHE)method is proposed to estimate the state.According to the estimated state and the physical constraints of the mobile robot,a similar MPC method is designed to track the trajectory of the mobile robot.In order to verify the effectiveness of the proposed theory and method,this paper uses Matlab software to simulate and verify.The results show that the multi-mobile robot formation strategy proposed in this paper is feasible and achieves an ideal control effect.