Thermally constrained motor operation for a climbing robot

Abstract

Climbing robots are especially susceptible to thermal overload during normal operation, due to the need to oppose gravity and to frequently apply internal forces for clinging. As an alternative to setting conservative limits on the motor peak and average current, we investigate methods for measuring motor temperatures, predicting motor thermal conditions and generating thermally constrained behavior. A thermal model, verified using empirical data, predicts the motor's winding temperature based on measured case temperature and input current. We also present a control strategy that maximizes robot velocity while satisfying a constraint on the maximum permissible motor winding temperature.