Influence of internal vibration modes on the stability of haptic rendering

Developing stable controllers able to exhibit a wide dynamic range of impedances is a persistent challenge in the field of haptics. This paper addresses the effect of internal vibration modes on the stability boundary for haptic rendering. A theoretical study that analyzes the influence of the first resonant mode on the maximum achievable impedance is presented. Experiments carried out on the LHIfAM haptic interface support the theoretical conclusions. A control architecture that overcomes the undesired effect of the resonant mode on the stability is also described.