Exploring the Value of Open Source in SI Engine Control 2011-01-0702
The notion of open source systems has been well established in systems software and typified by the development of the Linux operating system. An open source community is a community of interest that makes use of software tools in research and development. Their ongoing development is part of the free flow of ideas on which the community. The motivation for the work reported in this paper is to provide the research community in engine controls with a ready access to a complete engine management solution and the component parts.
The work described in this paper extends open source principles to engine control with a portable spark ignition (SI) control strategy assembled using Simulink. The underlying low level drivers are written in C and designed for portability. A calibration tool is written in C and works over a controller area network (CAN) link to the engine control unit (ECU).
The ECU hardware is based on the Infineon Tricore microcontroller. In the first implementation, the strategy was developed on the Infineon Powertrain Starter Kit (PSK) hardware. During the course of the work, the same strategy was implemented on the GEMS-K1, another Tricore based system developed by Tianjin University, People's Republic of China.
The reported work has made use of the Ford Zetec 1.41 engine on which practical tests have been conducted and a simple bench top spinning rig that allowed the timing functions of the systems to be developed.
The paper describes three mini-projects, each of which tests the capability of our system to support short duration and technically rich developments. In the first of the projects, an implementation of an
control has been tested in order to demonstrate the potential to automatically identify optimum spark timing on-line. In the second a knock detection algorithm and a simple control algorithm is developed that utilises the digital signal processing (DSP) functions of the target microcontroller. In the third individually estimated air to fuel ratio (AFR) values for the cylinders of a spark ignition engine are estimated from a single universal exhaust gas oxygen (UEGO) sensor output.