Dynamics of a four wheeled wall climbing robot

Abstract

In this paper, a mathematical model of a four wheeled independently driven Wall Climbing Robot (WCR) is developed. The consideration of only the kinematic model for a WCR may reduce its performance during sudden changes in acceleration and turning. To address this issue, a dynamic model that includes the wall/wheel interactions i.e., lateral and longitudinal frictional forces, is proposed. The effect of wheel slip is considered for a more realistic dynamic model. The models that are typically developed for the vertical contact forces, an important parameter affecting the frictional forces, assume equal weight distribution on the wheels. However, to accommodate the load shift due to the variation in acceleration along with the distribution of adhesion force, lateral and longitudinal acceleration components are also taken into account. The major components of this WCR model consist of the wheel dynamics, the wall/wheel interactions, the kinematics and the dynamics. Simulations are performed to demonstrate and verify the model. The suggested model in the future can be applied in the development of control algorithms for wheeled WCRs.