Feedforward and deterministic fuzzy control of balance and posture during human gait

The primary objective of this research is to model the biomechanical control system employed by the central nervous system (CNS) to maintain posture and balance of the head-arms-torso (HAT) during gait. More specifically, the intent is to stabilize a model of the upper body so that the HAT response is similar to that found experimentally in human subjects during gait. This is accomplished by using appropriate physiological parameters as feedback to generate realistic control signals at the hip musculature. The modelling includes the HAT musculoskeletal characteristics as well as pure neural time delays. The CNS control system is modelled by a linear state feedback controller as well as a hybrid fuzzy controller that has been adapted from a linear quadratic regulator. In addition, a newly derived feedforward component is demonstrated. It is expected that a better understanding of the human fait process will prove valuable in designing assistive devices and bipedal robots.