Effect of Direct Velocity Measurement on the Stability of Haptic Simulation Systems

The quality of the velocity signal required to implement linear viscoelastic virtual environments is of great importance for the stability of haptic simulation systems. In a typical haptic simulation system, the velocity is numerically estimated from position samples. The range of the implementable environment stiffness and damping for uncoupled stability is limited by quantization. In this paper, we analytically and numerically studied the effect of direct velocity measurement on the virtual environment viscoelastic dynamic range for guaranteed uncoupled stability and the passivity of the dynamics projected to the user. The analytical results are assessed through experiments conducted in a QET haptic knob testbed.