Transparency enhanced multirate wave variable control scheme with energy reusage

This paper presents a newly designed control scheme for haptic interaction with uniform sample rate virtual environment. In most practical application in haptic interaction, we lack the knowledge about the model of the sampling rate. Unfortunately, by using the conventional wave variable method, the impedance parameter should adjust accordingly to guarantee the passivity of the interaction. Considering the inconvenient of the wave variable method, a novel scheme, named multirate wave transformation with energy reusage, is introduced. The proposed control scheme re-harvests the energy leakage caused by sampling rate by an energy observer, and an energy reservoir is formed to accumulate the re-harvested energy. Then, an energy regulator reuses the energy to passify the haptic interaction. Furthermore, we also demonstrated by analysis that the proposed control scheme can achieve a better interactive transparency by comparison with the traditional wave variable method. Finally, the effectiveness and performance of the proposed control scheme are validated with a haptic rendering experimental platform.