Design And Motions Control Research Of A Variable Structure Two-wheeled Vehicle Robot

The variable structure two-wheeled vehicle is the combination product of the bicycle with two wheels before-after distribution and the Segway with two wheels left-right distribution,it's a new member of the family of two-wheeled vehicles.This robot can works in different working modes to adapt to different terrain environment and task requirements by changing the angle of its two handlebars.The research of variable structure two-wheeled vehicle is a system engineering,and balance control is the foundation.In this paper,we mainly studies some balance problems in the dynamic switching of the working modes.The main work is as follows:Firstly,kinematics and dynamics of variable structure two-wheeled vehicle are analyzed,then the holonomic and nonholonomic constraints of the system are derived based on the assumption of pure rolling of wheel and ground,and the relationship between the centroid velocity of two-wheels.Then,the system dynamics model is established by using Chaplygin method.Based on the dynamic model,the relationship between the driving torque of the wheel and the angle of the frame,the angle of the handlebar,the angle velocity of the handlebar is analyzed.Secondly,the physical prototype of the variable structure two-wheeled vehicle is designed and constructed,including the mechanical body and the measurement and control system platform.Thereinto,the measurement and control system used Industrial Personal Computer(IPC)and digital signal processor(DSP)as the control core.Inertial measurement unit(IMU),photoelectric encoder and current sensor etc.are combined together to gain the state variables of the system.ZigBee wireless module is used to complete the data upload and control command transmission.The upper monitor program of variable structure two-wheeled vehicle is developed based on VS2010 and MATLAB GUI,and a simple and convenient man-machine interface is designed for the System experiment operation.Thirdly,the dimensionality of system dynamics model is reduced in view of the special situation of mode switching in the case of synchronous rotating handlebar,the dynamical model under fixed turning bars is obtained.Used partial feedback linearization method,the balance controller of handlebar angle under 0 degrees and plus or minus 45 degrees are designed respectively.Simulation experiment and physical prototype experiment are investigated as well,and realized a series of balanced motion control under fixed turning bars.Fourthly,on the basis of the last step,the problem of situ mode switching under a range handlebar angle is studied.The situ mode switching balance controller of variable structure two-wheeled vehicle is designed based on partial feedback linearization method with parameters fuzzy tuning.Then the simulation experiment and physical prototype experiment of mode switching movement are investigated,and realized balanced control of situ mode switching motion under a range handlebar angle.Finally,the problem of mode switching motion in advance under a range handlebar angle is studied.On the basis of situ mode switching,adjust the expectation of frame pitch angle and wheel speed,then completed the design of balance controller mode switching motion in advance,and realized balanced control of mode switching motion in advance under a range handlebar angle.In this paper,a preliminary exploration for mechanical model and mode switching motion under a range handlebar angle of the variable structure two-wheeled vehicle robot is carried out.And the realization of the simulation and prototype experiment mentioned above will provides a reference for the further research on the mode switching and trajectory tracking control of variable structure two-wheeled vehicle.