Consensus Analysis And Design For Multi-robot System Based On Hybrid Dynamics

Many researchers have focused their attention on the consensus problem of multi-robot system in recent years. The so-called consensus is that how to achieve the same status based on the information exchange of multi-robot. In the control area, consensus in multi-robot system is one of important issues of coordination and control. With the improvement of network communication capabilities and continuous enrichment of network shared resources, more and more network transmission methods are applied to the communication in multi-robot system. Environment noise inevitably exists in practical communication system, and insertion of communication network brings the communication constraint issues such as delay, packet loss etc., which makes the analysis and design of the networked multi-robot system complex. To overcome the negative impacts of random delays, packet loss and environment noise on consensus for multi-robot system, this dissertation studies consensus problem of multi-robot system with random delays, packet loss and environment noise using hybrid dynamical system theory, algebraic graph theory, matrix theory, stability theory and robust H∞control theory. The main works are as follows:(1) The consensus analysis and design for multi-robot system with random delays, packet loss and environment noise under fixed communication topology are carried out based on asynchronous dynamical system method. The multi-robot system with random delays, packet loss and environment noise is modeled as an asynchronous dynamical system. According to stability theory and robust control theory, the system stability is analyzed by constructing appropriate Lyapunov function. The system robust exponentially stable controller parameters are derived by using the linear matrix inequality (LMI) method, as well as maximum allowable delay for system robust asymptotic stability. The relationship between the allowable packet loss rate for system robust exponential stability and the open-loop system structure is also shown in this section.(2) The simulation verification is conducted for multi-robot system with random delays, packet loss and environment noise under fixed communication topology based on asynchronous dynamical system method. A simulation model of multi-robot system in TrueTime environment is built, and the system evolution under the designed control algorithm is obtained, and the influences of time delays, packet loss and environment noise on consensus in multi-robot system are analyzed. The simulation results are given to verify the correctness and effectiveness of theoretical results in (1).(3) The consensus analysis and design for multi-robot system with random delays, packet loss and environment noise under dynamic communication topology are carried out based on switched system method. The multi-robot system with random delays, packet loss and environment noise is modeled as a switched system. The sufficient condition of robust asymptotic stability of multi-robot system with random delays, packet loss and environment noise under arbitrary switching is proposed, and the controller parameters are designed by constructing a multiple Lyapunov function and using the linear matrix inequality (LMI) method. The maximum allowable delay for switched system robust asymptotic stability is derived by constructing appropriate Lyapunov-Krasovskii functional and using LMI toolbox in MATLAB.(4) The simulation verification is conducted for multi-robot system with random delays, packet loss and environment noise under dynamic communication topology based on switched system method. A simulation model of multi-robot system in TrueTime environment is built, and the system evolution under the designed control algorithm is obtained. The simulation results are given to verify the feasibility and effectiveness of theoretical results in (3).(5) Complex multi-robot system composed of a huge amount of robots and the connections between them is called multi-robot network. In order to analyze and characterize multi-robot system, weighted network is introduced. And the relationship of network communication topology weight and communication parameters of multi-robot system is investigated briefly in the aspects of network topology, network performance index and channel capacity.Finally, a summary has been done in the dissertation. The further research is presented for the consensus problem of multi-robot system.