Dynamic Modeling And Control Of A Bicycle Robot

A variable structure wheeled robot is studied in this paper.It can work in three different modes:bicycle mode,Segway mode and tricycle mode.It can switch to the corresponding work pattern according to different work environment and needs.In this paper,the structural design,motion characteristics,dynamics model and control strategy of the robot are studied.First of all,this paper analyzes and compares the structure and movement characteristics of bicycle,Segway and tricycle and designs the mechanical structure of variable structure wheeled robot based on the switching demand.Besides,the motion characteristics of the variable structure wheeled robot are analyzed without the sliding friction,and the non-holonomic constraint of the switching process between the bicycle model and the Segway model and the bicycle model,Segway model are obtained according to different motion characteristics.Based on the Kane method,a dynamic model of a robot with a variable structure in a bicycle mode,a Segway mode and a switching process between two working modes is established.According to the approximate condition near the equilibrium point,this paper linearized the nonlinear dynamic model of the bicycle robot in bicycle mode,and designed the PID controller.This paper uses the Simulink module in Matlab to simulate the balanced control of the designed controller.It can be seen from the policy results that the designed PID controller can realize the roll angle of the robot,the angle of the front fork and the control of the velocity of the front wheel.Finally,after comparing the differences in the movement characteristics between tricycles,Segways and bicycles,a rollover-proof carriage structure was designed to make the tricycle sporty with bicycle movement.The grounding point of the bicycle rear wheel is similar to a hinge,and the bicycle frame will not swing when traveling straight,and the bicycle frame may be tilted at an angle during steering.Based on the class-hinge principle of bicycle grounding points,a hinge is designed at the junction of the three-wheeled vehicle compartment to achieve similar characteristics to bicycle movement.That can adjust the hinge angle in the straight to keep the car vertical,while turning to adjust the car deflection,to achieve the similar experience of riding bicycle.