Inversion-Based Intake Manifold Pressure Control System for Modern Diesel Engines

An improved model-based two-degree of freedom control system for the intake manifold pressure in passenger car diesel engines is described in this paper. The aim of this control system is to track the air charge setpoint rapidly and precisely. To achieve this, an inverse model of the intake manifold dynamics is included in the feedforward control path. The system parameters which are necessary to calculate the inverse model are setpoints from other control loops in the gas system. These generated setpoint values allow for decoupling of the individual control loops in the gas system as far as possible. The parallel linear feedback controller is designed to further improve the accuracy of the control system. The calculated feedforward control signal and the feedback control variable additively generate the effective opened area of the intake throttle valve. Due to its model-based structure, the improved control system proposed will require less calibration effort than current production-code controllers and that the calibration can be partially carried out using simulation. This is also the main motivation for the development of this controller. The proposed control algorithm can be easily implemented on the standard electronic control unit (ECU) of passenger car diesel engines. For testing and validation, the production-code controller function of the ECU has been replaced by the new control approach using a bypass with a rapid control prototyping. Experimental results are provided and show that the new control system achieves a performance that is similar to the production-code controller.