Bond Graph Modeling and Simulation of a Differential Drive Mobile Robot

Wheeled mobile robots (WMRs) are being used in many walks of life due to their simple structure and easy control. Furthermore, a differential drive robot is the simplest form of a WMR, which is having two independent actuators to drive its two tractive wheels. The steering is performed using the difference of velocities of two wheels; hence, two wheels velocities are manipulated in order to control the velocity and orientation of the robot. Modeling is the first step for the control system design. A kinematic model is not enough to represent the real behavior of the robot. Therefore, this paper deals with the dynamic modeling of a differential drive mobile robot. The model considers the multi-domain nature of the robot and includes electrical actuators and mechanical dynamics. A multi-domain graphical modeling tool called bond graph (BG) is used to develop the robot’s model. The developed BG model is verified through simulation and the robot’s motion is analyzed on the surfaces with different coefficients of friction.