Göm meny

Abstract



Wastegate Actuator Modeling and Tuning of a PID Controller for Boost Pressure Control


In some turbochargers, boost pressure is reduced by opening the wastegate valve. In a modern turbo charged car, the most common way for opening the wastegate is with a pneumatic actuator and an air control solenoid, controlled by the ECU. In the control systems studied the ECU utilizes a static feedforward and a PID controller, for the purpose of making the boost pressure follow its reference value. With no systematic method for tuning the controller, this can be time consuming, and a set of well defined experiments to determine PID parameters are desired. When test time in a real engine is limited or expensive, it is advantageous to work in a simulation environment before doing live tests. A model for the wastegate actuator and air control solenoid is developed in the thesis. This is used to simulate controller performance before any tests in a real car is performed. In the thesis a tuning method for the PID controller based on step responses is proposed. The tuning method evaluated is the IMC-choice of controller for a second order system, and it has a single design parameter not given by the experiments. The controller is shown to give desired behavior when the static feedforward is correct or has small error.

Andreas Thomasson

2009

Download Article (pdf-file)Show BibTeX entry

Informationsansvarig: webmaster
Senast uppdaterad: 2021-11-10