Kinematics Modeling And Mobility Research Of All Wheel Steering Mobile Robot

With the development of related technologies,the application of mobile robots is gradually deepened and broadened.Among them,all wheel steering mobile robot has attracted much attention because of its high mobility.In this paper,the kinematic modeling method and mobility analysis method of the type ? and type ? all wheel steering mobile robots designed by the research group are studied.The main work of this paper is as follows:First of all,the structural characteristics and hardware system composition of the I-type and II-type all wheel steering mobile robots developed by the research group are analyzed,and the differences in body geometry,wheel group mechanism,actuator and bus layout between the two robots are compared.Among them,the wheel group steering mechanism of type ? all wheel steering mobile robot can realize 360 ° free rotation by adding conductive slip ring to get rid of the wiring limit,and the type ? mobile robot optimizes the bus layout to improve the real-time control of the robot;Secondly,based on the pure rolling hypothesis and no lateral sliding hypothesis of the wheel of the mobile robot,the kinematics models of the all wheel steering mobile robot are established under the different constraints between the wheels,including straight travel,in-situ rotation and Ackerman steering,and the relationship between the input and output of these kinematics models is calculated;Then,the mobility of the all wheel steering mobile robot with four-wheel drive and four-wheel steering and the mobility of the mobile robot with different types of wheel groups are analyzed.In addition,the mobility of this kind of all wheel steering mobile robot in straight motion model,in-situ rotation motion model and Ackerman steering motion model is discussed.The mobility of type ? and type ? all wheel steering mobile robots is also analyzed from the real-time nature of the control robot.The direction controllability of type ? and type ? all wheel steering mobile robots is analyzed from the steering ability of wheel set mechanism.The analysis shows that the type ? all wheel steering mobile robot has good real-time performance and the steering mechanism of wheel group can turn 360 ° freely,that is to say,its mobility is better;Finally,based on the simulation platform of webots,the model of all wheel steering mobile robot is established,and the straight motion model,in-situ rotation motion model and Ackerman steering motion model are simulated and verified.The X and Y set of punctuation points of all wheel steering mobile robot are collected through the simulation experiment,and the trajectories and theoretical graphs of these three kinematic models are fitted by MATLAB.It is verified that the three motion models are correct.