Estimating an LPV model of neuromuscular admittance with grip force as scheduling parameter

Estimating an LPV model of neuromuscular admittance with grip force as scheduling parameter

Pronker, A.J.

Abbink, D.A. (mentor)

Aerospace Engineering

Control & Simulation

2016-08-18

Development of adaptive haptic shared control system requires understanding of the adaptive nature of the driver’s neuromuscular system. In this study, linear parameter varying modeling techniques are proposed to identify changes in the admittance of the driver’s arm. The admittance describes the relation between the torque applied to the steering wheel and steering wheel angle output. By conducting two experiments it is investigated whether grip force applied to the steering wheel serves as an appropriate scheduling variable for a LPV model. In our approach, first tracking tasks with torque perturba- tions applied to the steering wheel are performed with varying boundary widths to evoke changes in admittance. The relation between grip force and admittance is investigated by estimating neuromuscular stiffness and damping parameters and measuring the force applied to the steering wheel using pressure gloves. An LPV model is identified by linear interpolation between LTI models identified for each condition. Second, a driving task is performed in a fixed-base driving simulator to analyze the variance in grip force and changes in admittance between wide and narrow roads. The results of the driving task are used to assess the validity of the LPV model during driving tasks. It was found that the stiffness and damping parameters varied proportionally with the grip force. Although small variations in grip force levels are found between subjects, it is concluded that grip force is an appropriate scheduling variable for an LPV model. The relation between grip force and admittance was similar during driving tasks compared to the tracking tasks. The derived LPV model accurately describes the changes in the neuromuscular system over the range of grip force variations observed during the driving task. For further validation of the LPV model in the time-domain it is recommended to use time- varying boundary tasks.

neuromuscular admittance
time-varying
grip force
LPV
driving behavior

http://resolver.tudelft.nl/uuid:73e8dd75-207b-4bfc-aaa5-bcd4fa3e0242

Student theses

master thesis

(c) 2016 Pronker, A.J.