Abstract
In tracking or position control of an electropneumatic servodrive modelling errors like the leakage mass flow rates and the gravity torque or also the dry friction, constitute a serious constraint when designing a control law. We describe in this paper a robust control approach based upon a local change of coordinates and a nonlinear sliding mode control synthesis. An integral surface is used and this allows us to overcome the use of an accelerometer. Experimental tracking results are then related.