Automating Engine Startability Calibration
Automating engine startability calibration to reduce the development period and improve engine design
Project Sponsor: Honda R&D Americas
An immense amount of research goes into a car's engine to ensure it will always start regardless of the conditions. If engineers do not take into account every possible factor, it could negatively impact the long-term reliability of the engine, or even leave someone stranded. A poor engine start also increases emissions due to an incorrect air/fuel ratio (AFR).
To meet fuel economy and emissions standards, automatic engine stop/start systems have become popular. Called Idle Stop by Honda, these systems automatically turn off the engine when the vehicle comes to a stop to reduce fuel consumption and emissions. During a driver's typical commute, a modern car equipped with this feature might go through the startup cycle dozens of times.
Engine startability calibration is a complex process and has a long development period that lasts 250 days, or approximately 4,000 facility hours. It requires almost 500 different tests. Additionally, manual engine calibration is highly subjective and many factors can affect the quality of calibration.
Automating engine startability calibration can solve these issues.
By the end of the project, SIMCenter developed a method to allow 24/7 testing on a fully automated start cart (Figure 1). SIMCenter also developed a software tool for detecting and scoring knock and stumble during engine hot restart (Figure 2).
The new calibration process proved to reduce calibration engineers' required effort and time, and it also reduced the cost associated with the development process. Due to these favorable results, Honda R&D Americas has already implemented the new calibration method into its engine development process.