Modelling and Compensation for Transmission Error of Timing Belt in Legged Robots

The timing belt transmission offers numerous advantages for legged robots, including high efficiency, impact absorption and large range of joint motion. However, the transmission error under high load remains challenging to locomotion control and further applications of belt transmission. Traditional linear models cannot effectively model the belt deformation under a wide range of tension variations due to the nonlinearity. In this paper, we propose a model of the compensation for the belt transmission error based on the pretension and torque of the pully. The adopted approach bypasses the complexity of elaborate physical model derivations, yielding a non-linear model for transmission system errors through straightforward fitting. Based on the proposed model, an error compensation control is investigated and tested with an one-DoF leg prototype of legged robot. The alignment between experimental results and theoretical analysis demonstrates the accuracy of the modeling and the effectiveness of the error compensation control method. The proposed model provides a convenient and straightforward solution to effectively compensate for the belt transmission errors in legged robots.