Motion Modeling Of Two-wheel Differential Drive Mobile Robot

Two-wheeled differential drive mobile robot, with features such as simple structureand easy control, has been one of the most widely used mobile robots and its kinematicmodel is an important part of researches on mobile robot.At present，studies related to two-wheel differential drive mobile robot usuallyneglect the influence of dynamic factors, including the dynamic performance of themotor bottom driver. But in real robot system, the kinematic behavior of the robot willchange due to the changes in the dynamic response process of drive system that isaffected by loads of the robot. Two-wheeled differential drive mobile robot is amulti-input multi-output (MIMO) control system and its corresponding kinematic modelis subject to classical nonholonomic constraints. Besides, the motor drive circuit of thesystem contains a double closed-loop control structure with nonlinear links, which turnsthe system into a nonlinear system consisting of several nonlinear links, so it isnecessary to employ nonlinear modeling method to obtain the model of the system.Thus the establishment of the kinematic model of the two-wheeled differential drivemobile robot, with the dynamic behavior to be considered, will be of great theoreticaland practical significance to the accurate description and control of the motion behaviorof the robot.Based on the above consideration, the "equivalent" modeling approach is adoptedto establish the motion model of a two-wheel differential drive mobile robot, the mainresearch work are as follows:①The motion model of two-wheel differential drive mobile robot based on"equivalent" modeling approach is proposed. By considering the wheel load distributionand translation of equivalent moment of inertia of the robot, the equivalent moment ofinertia corresponding to each driving wheel can be obtained. The dynamic response ofthe drive wheels can be described through a combination of simplified model of DCMotor Double Closed Loop System. The motion model of robot described by"Equivalent" state space can be further proposed through the kinematic model of therobot.②A kind of parameter tuning method of robot motion model based on geneticalgorithm is proposed.③To validate the motion model, a novel load-adjustable two-wheel differential drive mobile robot is designed in this paper. The experimental results show that themotion model and modeling method are effective.