MODEL-REFERENCE ADAPTIVE-CONTROL OF HEART-RATE DURING WHEELCHAIR ERGOMETRY

This study used parametric methods to identify a model of the wheelcha ir user's heart rate response to changes in physical workload while on a wheelchair dynamometer. A model reference adaptive control (MRAC) a lgorithm was developed based upon the results of the system identifica tion process. Based upon the subject's maximum speed, ten random level s from zero to maximal speed were selected to form a tracking input ve ctor. Two autoregressive models with exogenous inputs were developed u sing a stepwise regression-based algorithm. Analysis of variance resul ts imply that the model development and model validation groups were d ifferent. Linear regression was used to compare the model predicted he art rates with recorded heart rates for the validation group. Predicte d heart rates from both models were significantly correlated with the data recorded from the validation group. The simulation for all subjec ts converged for all three inputs. The application of indirect model r eference adaptive control appears to be feasible for controlling heart rate kinetics of people with paraplegia or tower limb impairments dur ing wheelchair propulsion on a computer-controlled wheelchair dynamome ter.