Transparent haptic interaction for admittance type haptic interfaces

A transparency oriented self-adaptive algorithm applied to admittance type haptic devices is proposed, which is based on an inner velocity loop PI controller with desire force feed-forward. Besides, an on-line iterative approach is presented to estimate the stiffness parameter of the controller. The systemic stability proof of the algorithm is realized by constructing Liapunov stability criterion with system states. The comparative experimental results show that the new method can accommodate the contact stiffness variation and effectively improve the transparency of haptic system.