A haptic control interface for a motorized exercise machine

Abstract

A haptic interface is generated for a powered arm curl machine for modulating resistance "on-the-fly" during strength training and rehabilitation. Force signals from a load cell are input to an impedance loop based on the desired resistance law, which then outputs position commands to a servomotor. The kinematics between the actuator drive and arm curl angle are derived, and the admittance control implementation used for realizing the resistance laws is described. Preliminary experimental results are presented for viscous and inertial control laws.