A fundamental conflict between performance and passivity in haptic rendering

This paper identifies a fundamental limitation on haptic rendering performance induced by passivity requirements. This limitation arises when the target closed-loop response requires feedback compensation of hardware dynamics. The intrinsic human-in-the-loop nature of haptic rendering further requires passivity of the closed-loop response. The conflict between performance and passivity that we discuss is a consequence of feedback bandwidth constraints, not sampling or quantization. Key to our analysis is an interpretation of a Bode gain-phase integral relationship that relates magnitude at low frequencies to phase at high frequencies.