Three-input-three-output air path control system of a heavy-duty diesel engine

In this paper, the control requirement of the air path system of a Heavy Duty (HD) diesel engine which was equipped with a High Pressure (HP) Exhaust Gas Recirculation (EGR), a Variable-Geometry Turbocharger (VGT), and an Electric Turbocharge Assist (ETA) is discussed. A Three-Input-Three-Output (3130) multivariable control structure is proposed. The engine dynamic model required for controller design was obtained using system identification and the controller was tuned by solving an Hoo optimization problem. The engine experimental test results show that this 3130 closed-loop control system has excellent tracking performance, disturbance rejection performance, and gain scheduling capability. The control system has been demonstrated to work with a practical ETA device to make a substantial improvement to engine transient performance.