Modes Switching Control Of A Variavle Structure Wheeled Robot

Two-wheeled robot is a very important subject in the field of intelligent robot.At present,the research on two-wheeled robot at home and abroad focuses on the bicycle robot and the Segway robot.In daily life,the bicycle robot can be generally drived at high speed in the environment of rough road,but it is usually inconvenient to turn in narrow sections because of the large rotating radius;Segway robot is generally suitable for driving at low speed in flat terrain,and can turn freely in narrow sections.If the advantages of these two robots are combined,they will have better applicability to real and complex environments.In this paper,the dynamic modeling and control of a kind of variable structure wheeled robot are studied,which combines both advantages and characteristics.This can bring new directions and possibilities to the field of wheeled robots,which is of great significance.Firstly,the kinematics of the general motion form of the variable-structure wheeled robot is analyzed in this paper.According to chaplygin equation,the system dynamics model is established,which reveals the mechanical coupling relationship of each part of the variable-structure wheeled robot.And two kinds of dynamic models are deduced.The dynamic model of general motion form is treated as a special case in Bicycle mode,and is compared with the dynamic model of bicycle robot based on Chaplygin equation.The dynamic model of general motion form is treated as a special case in Segway mode,and is compared with the dynamic model of Segway robot based on Chaplygin equation.They confirm the validity of the established dynamic model of general motion form.The virtual prototype of the robot is established by ADAMS,and the joint simulation research of ADAMS and Simulink is carried out.In the condition without the control algorithm,the natural dumping process of the robot is simulated.For the dumping process of the robot,the dynamic model is numerically simulated by MATLAB.The results of numerical simulation are compared with those of co-simulation,and the correctness of the dynamic model of general motion form is verified.In this paper,the controller design of robot nonlinear system is carried out by two methods.One is that the original system is extended through dynamic expansion algorithm,based on general motion form of the dynamic model.Then the extended system is divided into linearized subsystem and zero dynamic subsystem.Based on the partial feedback linearization theory,the linearized subsystem is decoupled from the input and output,and the zero dynamic subsystem is stabilized by the central manifold theorem,and the controller is designed.Another method is that the differential homeomorphism nonlinear transformation is constructed by analyzing the internal structure of the system,and the affine nonlinear system is transformed.After reselecting the decoupling matrix,the system is divided into linearized subsystem and zero dynamic subsystem.Based on partial feedback linearization theory,the input and output of linearized subsystem are decoupled,and the controller design of linearized subsystem and zero dynamic subsystem is completed by cascade sliding mode control theory.The simulation on MATLAB/Simulink is carried out for these two controllers,which verifies the effectiveness of the controllers.Finally,the design of the robot prototype and the device selection of the measurement and control system are completed,and the prototype of the variable structure wheeled robot system is preliminarily built.