Stable haptic interaction control using energy bounding algorithm

Stability is one of the important considerations in the design and control of haptic simulation systems because unstable behavior may cause damage on human operator or deterioration of realistic haptic feeling. In this paper, a basic theory on the passivity condition for the sampled-data system has been reviewed and energy relations on each subsystem of haptic simulation have been investigated. Based on this, we propose a novel energy bounding algorithm for stable haptic interaction control. The proposed energy bounding algorithm restricts the energy that is generated by the sample and holds within the energy consumable by the physical damping in a haptic device and makes the virtual environment and controller passive as well. This algorithm, therefore, guarantees the passivity condition of the haptic simulation regardless of sampling frequency. Experimental validation with a commercial haptic device has been presented.