Research On Consistent Tracking Control With Finite Time For Multi-Agent Systems With Unknown Control Direction

In recent years,with the rapid development of control science and engineering,the consensus control of multi-agent system has been widely applied to multiple unmanned boats,multiple unmanned ships,multiple unmanned aircraft,multi-sensor network and other systems,which has become one of the hot topics in modern control theory.In this thesis,the problem of consensus tracking control for multi-agent systems with unknown control direction is studied.By using adaptive backstepping strategy and finite-time command filtering technology,the finite-time consensus tracking controller is designed considering the external environment interference and unknown nonlinear dynamics in the system.The research contents are mainly summarized in the following three parts.1.For the second-order multi-agent system with unknown control direction,the control problem of finite-time consensus tracking in the form of strict feedback is considered.Based on backstepping control strategy and neural network approximation technology the high-order nonlinear problem in multi-agent system can be solved.In order to solve the problem of calculation explosion caused by controller design in backstepping process,finite-time command filters are designed to ensure that the output of each filter can track the virtual control input signal with high precision in finite time.The error compensation signal is defined to compensate the filtering error.Based on Nussbaum type function,virtual control signal,control input signal and adaptive law are designed to solve the problem of unknown control direction.Numerical simulation shows the effectiveness of the research scheme.2.For the high-order multi-agent system with unknown control direction,the control problem of finite-time consensus tracking in the form of non-strict feedback is considered.Firstly,the backstepping control strategy based on command filtering and fractional power is proposed.This strategy not only solves the problem of computational explosion,but also ensures that the states of each agent can follow the leader's output with the desired accuracy in finite time.The error compensation signal is designed to compensate the error caused by filtering.The fuzzy logic system is adopted to estimate the unknown complex nonlinear dynamic,and the difficulty of controller design caused by the state variables in the non-strict feedback system is solved through the expansion and reduction of inequalities.By introducing Nussbaum type function,the intermediate virtual input signal and the control input signal based on adaptive control law are designed respectively to conquer the difficult problem of unknown control direction.The simulation result is given to prove the effectiveness of the control algorithm.3.For the multi-manipulator system with unknown control direction,the adaptive fuzzy finite-time consensus tracking control under uncertain dynamic and environmental disturbance is studied.The finite-time command filtering scheme is adopted to avoid the calculation explosion of traditional backstepping control algorithm,and the error in the filtering process is eliminated by error compensation signal.Fuzzy logic system and adaptive control technology are combined to approximate and estimate the unknown nonlinear dynamics in multiple manipulator systems.A continuous non-smooth input control torque based on Nussbaum function is established to eliminate the influence of unknown control direction and ensure that the consensus tracking error can converge to the expected neighborhood of the origin in finite time.The effectiveness of the research scheme is given by numerical simulation.