Consistency Control Of Multiple Underwater Robots Based On Adaptive Fuzzy Backstepping Technology

In recent years,due to the increasingly serious shortage of land resources,the worldwide competition for marine resources has intensified.Underwater vehicle can play an important role in ocean exploration,so more and more research work has been done on it.In many research directions of underwater vehicle,the control of multi-underwater vehicle system has gradually occupied an important position.Using multiple underwater vehicles to form a system can effectively improve work efficiency and meet more work needs.Consensus tracking control is the basis of the multi-underwater vehicle system control.By designing a consensus tracking algorithm for each individual in the system,it can control all the states of the underwater vehicle,such as position or velocity,to achieve the desired control objectives.There are many kinds of commonly used underwater vehicles at present,the research object of this paper is autonomous underwater vehicles(AUV).Aiming at the consensus tracking control problem of multi-AUV system,this paper combines graph theory and adaptive fuzzy backstepping technology to construct dynamic surface controller and command filtering controller respectively by using backstepping method,which can effectively track the consensus of multi-AUV system.The main research results are as follows:Firstly,the consensus tracking control of multi-AUV system based on adaptive fuzzy dynamic surface technology is studied.Selecting the appropriate multi-AUV system model,describing the multi-AUV system with the knowledge of graph theory,using the fuzzy approximation theorem and combining the adaptive technology to deal with the non-linear items contained in the system,and using the dynamic surface technology to solve the inevitable "computational explosion" caused by the continuous derivation of the virtual control function when using the backstepping method to recurse the final controller.Finally,the final adaptive fuzzy dynamic surface controller is obtained,the stability of multi-AUV system is proved by Lyapunov theory,and the Simulink module of MATLAB software is used for experimental simulation.The simulation results show that the proposed method is feasible and efficient.Secondly,the consensus tracking problem of multi-AUV system with input saturation based on adaptive fuzzy command filtering technology is studied.The multi-AUV system with input saturation is described with graph theory,and the non-linear term in multi-AUV system with input saturation is processed by using the fuzzy approximation theorem.Then,after the virtual control signal is constructed recursively by using backstepping method,all the virtual control signals are processed by command filters to effectively deal with the inevitable "computational explosion" in the process of backstepping recursion.At the same time,error compensation mechanism is introduced to effectively reduce the impact of filtering errors in the system.Finally,it is proved that the whole system is semi-global uniform bounded,and the simulation environment is built in the computer for simulation.The simulation results show that when the input signal is limited,the adaptive fuzzy command filter controller designed in this paper can also achieve the consistency control of the system.Finally,adaptive fuzzy dynamic surface control method and adaptive fuzzy command filtering control method are compared and studied.Through comparison,it can be obtained that although the two control methods both can achieve good control effect,due to the introduction of error compensation mechanism in command filtering technology to eliminate filtering error,its tracking speed is faster than that of dynamic surface technology,and the tracking effect is better than that of dynamic surface technology.