Application Research Of Variable Universe Adaptive Fuzzy Control In Robot Trajectory Tracking

With the development of science and technology,manipulator system has become indispensable equipment to the field of industrial control,and gradually spreads into other areas.The core of Manipulator system is control system,as one of the two major motion control problems of robot manipulator,trajectory tracking control has become the current research hotspot.The main purpose of the manipulator trajectory tracking control is making the joint angular displacement,angular velocity and other state variables of robots track the given trajectory by exerting control torque to manipulator joints,and finally realizing the specified processes smoothly fulfilled by manipulator.With the improvement of living standard,people put forward higher request on the precision of manipulator trajectory tracking.Not only can realize point-to-point tracking,general linear tracking and curve tracking,but can realize high-precision tracking of any specified path.However,manipulator system itself is a highly nonlinear and strong coupling complex system with multiple inputs and outputs,all of these make it difficult to get the accurate mathematical model of the manipulator system,combined with the changes of loads,external factors such as random disturbance and uncertain factors of model itself which greatly increased the difficulty of the manipulator trajectory tracking control.So this paper studies on the problem of manipulator trajectory tracking control,introducing the idea of variable universe,and puts forward a kind of variable-universe adaptive fuzzy control method with high-precision tracking by making full use of advantages of traditional fuzzy control,such as simple design and independence to accurate mathematical model of the object,and makes up for its disadvantage of the low control precision.The main research points are as follows:Firstly,this paper sets up the manipulator dynamics model based on Lagrange equation,and analyzes the feature of the model,preparing for subsequent designs of controller.Secondly,for manipulator trajectory tracking problem,designs a fuzzy controller in MATLAB,and verifies the proposed fuzzy controller has the advantages of good robustness and independence to accurate mathematical model of the object by multi-group simulation results in the SIMULINK,but has the problem of low control precision.Aiming at this problem,this paper introduces the idea of variable universe,and designs a contraction-expansion factor of the domain,realizing the design of a variable universe adaptive fuzzy controller to manipulator trajectory tracking by writing S function,and verifies its effectiveness by simulating.Finally,through the rich simulation experiments,this paper fully proves that the variable universe adaptive fuzzy controller has the great superiority of the traditional fuzzy controller which is a kind of high-precision adaptive fuzzy controller having the features of simple design,limited adjustable parameters and good stability,and is very suitable for using in the manipulator trajectory tracking control now with a higher accuracy.