Transparency Oriented Virtual Coupling Design: New Approach and Application to a Novel Admittance Haptic Device

A novel admittance haptic device which has low inertia and high speed to guarantee the high force bandwidth for the haptic interaction system is presented. Friction wheel is used to implement a rapid adjustment of the velocity loop. According to the admittance character of the haptic interface, PI velocity feedback control is utilized in the haptic interaction system. By introducing the virtual coupling into the system, Llewellyn's stability criteria in circuit theory is used to derive the constraint conditions to guarantee the system's absolute stability. Furthermore the parameters of the virtual coupling are optimized oriented to high transparency of the system. Man-machine haptic interaction system is established with the novel admittance interface. The experimental results indicate that optimized virtual coupling guarantees the large range stability, as well as improving the transparency effectively.