PIβDα Controller in the Human Machine Systems

This paper investigates the control of an electric vehicle by a human operator and the techniques needed to compensate for the operator’s control deficiencies. Several classes of human operators, of various ages and health conditions, are analyzed. It is shown that the human operator can be characterized by an integrator model with the fractional exponent $\beta\in[0.8-1.6]$. Particular attention is paid to people with Parkinson’s disability for whom the exponent $\beta$ tends to value of1.5. The fractional model of the human-machine system is determined. Control systems based on the use of observers for the estimation of human state components and hierarchical control systems are studied. The stability conditions are obtained by Lyapunov techniques. Experiments on a wheelchair driven by a person with Parkinson’s disability confirm the correctness of the proposed solutions.