Pulse-Modulated Locomotion for Computer Animation

In this paper, we address the problem of animating and controlling the locomotion of bodies which are propelled by pulse-like and periodic muscle activation. This kind of locomotion mode is encountered in a variety of real animals and an even larger variety of imaginary creatures could be propelled in this way. We propose a step-by-step methodology for the design of feedback controllers that can propel a dynamic model with an "intelligent" pulse-train of muscle efforts. The idea is to proceed in three steps: (i) a feedback controller is designed just as if muscles could deliver continuously regulated efforts. (ii) a pulse-modulator is inserted into the feedback controlled system, so as to take the muscle activation pattern into account. (iii) Synchronised kinematic cosmetics are added to the motion. The technique is illustrated by applying it to dynamic models of increasing complexity.