On speed estimation from incremental encoders with tunable error bounds

In many mechatronics applications, the knowledge of the rotational velocity of a shaft is a key feature and it may result into a fundamental measurement for control and safety. To this aim, encoders are now the leading speed sensing technology, because of their simple rationale and the reduced cost. To overcome the intrinsic limitations of such a technology, sophisticated techniques have been developed, which can enhance the speed estimation accuracy. As a drawback, significant computational burden is needed. In this paper, we propose a novel switching technique that guarantees both the boundedness of the velocity estimation error and the practical implementation on commercial devices. Experimental results are additionally provided to demonstrate the estimation improvement of the proposed approach with respect to other available techniques.