Sliding Mode Control for Diesel Engine Air Path Subject to Matched and Unmatched Disturbances Using Extended State Observer

The paper develops a sliding mode controller via nonlinear disturbance observer for diesel engine air path system subject to matched and unmatched disturbances. The proposed controller is based upon a novel nonlinear disturbance observer (NDO) structure which uses the concept of total disturbance estimation in order to estimate simultaneously the matched and the unmatched disturbances in the system. This estimation is then incorporated in a composite controller which alleviates the chattering problem and maintains the nominal performance of the system in the absence of disturbances. Simulations results of the proposed controller on a recently validated experimental air path diesel engine model show that the proposed methods exhibit a better performances comparing to the baseline SMC in terms of reducing chattering and nominal performances recovery.