Backstepping Control Of Voltage-Driven Robotic Manipulators With Input And Output Constraints

With the development of modern industry,the robotic manipulators have been used more and more widely,and the precision requirements of the robotic manipulators have been getting higher and higher.In actual operation,some unknown nonlinear items often exist in the model of the manipulators,and the input and output of the manipulators may be with some constraints,which make the design of the controller more difficult.In order to improve the practicability of the controller,the actuator motor at the joint of the robotic manipulators should be taken into account in the model and the voltage shoud be used as the drive signal.Therefore,designing of high-precision controllers for Voltage-Drive manipulators with input and output constraints has become a hot research direction now,it has high application value.In this thesis,a Voltage-Driven robotic manipulator is taken as the research object,and the trajectory tracking control of the Voltage-Driven robotic manipulator with input and output constraints is studied.The main work is as follows:1.Model the manipulator and analyze its characteristics.Firstly,the dynamic model of the manipulator is established by using the Lagrangian dynamic equation method.Then,the model of the Voltage-Driven manipulator is derived by combining the DC motor model.Then,introduce the RBF neural network and the constraints in the robotic manipulator system.2.For the Voltage-Driven manipulator with constant output-constraints,two kinds of backstepping controllers are designed based on RBF neural network and traditional barrier Lyapunov function,tangent barrier Lyapunov function.Then,a modified barrier Lyapunov function is proposed and the advantages of it are analyzed,a backstepping controller is designed based on the modified barrier Lyapunov function.Finally the effectiveness of the proposed methods are verified by simulation,and the performance of the three methods are compared.3.A backstepping controller based on modified barrier Lyapunov function is designed for the Voltage-Driven manipulator with time-varying output-constraints.Then the effectiveness of the proposed controller is verified by simulation.4.For the Voltage-Driven manipulator with intput and output constraints,the nonlinear saturation part is modeled,and a backstepping controller is designed based on the RBF neural network and the modified barrier Lyapunov function.Then the effectiveness of the proposed controller is verified by simulation.