Stability and a control strategy of a multilink musculoskeletal model with applications in FES

This paper introduces a relegated control strategy for point-to-point movement of musculoskeletal systems driven by redundant actuators. The actuator system is partitioned to two functional groupings referred to as gravity compensators and movement generators. Unlike dynamic optimization methods, relegation of control enables real-time computation of control signals to the muscle actuators. It is shown that this strategy significantly reduces the degree of coactivation needed to stabilize the movement. The real-time nature of this strategy coupled with reduced coactivation makes the proposed strategy amenable for multichannel control of parapalegics through functional electrical stimulation. Stimulations of a three-link sagittal system are conducted to test the algorithm for a bowing movement.