A Generic Model, and its Validation, for the Translational Systematic Errors in Synchronous Drive Robots

Synchronous Drive Robots (SDR) are seeing increasing use as service robots in dynamic environments. Due to the changing scenery in dynamic environments, the accuracy of proprioceptive sensors such as odometry is of greater importance. This paper proposes a generic kinematic model for the translational systematic odometry error in an n-wheeled SDR (n ≥ 3). An unexpected behaviour of SDR is the curved path when commanded to translate, which varies with wheel orientation (which changes when commanded to rotate.) This is caused by the traction force of each wheel around the centre of mass of the robot acting as a moment. There is a further odometry error due to wheel misalignment, which does not affect the path curvature, but creates a yaw. Compared to existing works, the proposed model is explicitly validated in the instance of a 3-wheeled SDR.