Backstepping control integrated with model predictive control for selective catalytic reduction system of diesel vehicle

摘要

emission from diesel vehicles has become an environmental problem, and regulatory standards have been strengthened with the real driving test. Selective catalytic reduction (SCR) with an active urea dosing system is one of the promising aftertreatment systems for both heavy-and light-duty vehicles. This study proposes backstepping control integrated with model predictive control to determine the amount of urea dosing. First, we prove that the subsystem of SCR is input-to-state stable with respect to the disturbances regardless of the value of the coverage fraction. Second, the desired coverage fraction of the catalyst is determined by solving the finite-horizon optimal control problem with the information of measurable disturbances. The backstepping control approach is then applied to determine the value of the manipulated input to achieve the desired coverage fraction. Compared to the results of the backstepping controller with a fixed coverage fraction setpoint, the proposed controller can reduce SCR-out NO