A comparison of two robust control techniques for throttle valve control subject to nonlinear friction

Throttle valves for internal combustion engines suffer from considerable nonlinear friction
in their mechanisms that is difficult to model and subject to significant variations due to changes in
temperature and wear over the lifetime. The stick slip friction component is particularly troublesome.
This presents a challenge to control system designers when it is important to obtain a prescribed
dynamic response to reference input position changes. The contributions of this paper are a) the
comparison of two different robust control techniques (sliding mode control and observer based robust
control) aimed at overcoming this difficulty and b) a new simple but accurate nonlinear friction model
for simulation. The control system performances using these techniques are compared with one
another and with the performance attainable with a conventional PI controller.

Citation:
Pedersen, J. and Dodds, S., (2011) "A comparison of two robust control techniques for throttle valve control subject to nonlinear friction" Advances in Computing and Technology, University of East London, January 2011, 91-99.