Simplified model of a single-wheeled self-balancing robot in mathworks® simscape multibody™

The paper deals with a single-wheeled self-balancing mobile robot type, usually named ballbot. During the design process of a ballbot prototype a model with reduced complexity but effective performance is helpful to define and analyse features of the perceived solution. A model of a ballbot based on a simplified modelling approach is presented. Assumptions to describe the effects of force transmission between main inertial components of a ballbot are described. Appropriate kinematic constrains between the driving ball of the robot and its actuators are developed and implemented in a MathWorks® Simscape Multibody™ environment. The software model is then tuned to the characteristic parameters of the ballbot prototype. Dynamics has been intrinsically evaluated by the software solver and an efficacious formulation of the frictional effects has been introduced with an all-inclusive equivalent friction torque. Two different tests have been carried out and used for reference: position control and force disturbance response. Comparison between experimental and simulation results are shown and analysed to validate the simplified modelling approach for the ballbot.