Sliding Mode Control of Automotive Powertrains with Uncertain Actuator Models

An alternative formulation of the sliding mode control method for dealing with the uncertainties in actuator or control dynamics is presented in this paper. The advantages of the formulation are in the reduced computational requirements and simplified procedures for meeting robustness and performance requirements. The method is then applied to control an automotive powertrain system, whose dynamics are highly nonlinear. In particular, coordinating engine and transmission control variables to perform clutch-to-clutch shifts is illustrated. The design objectives are to provide smooth transients for passenger comfort and to reduce clutch energy dissipation requirements for component longevity. The robustness and performance characteristics of the designed controller are demonstrated for a case that involves neglected actuator dynamics, whose bandwidth is very close to the frequency of the controlled system dynamics.