Using MathWorks tools for Model-Based Design, Nissan reduced development time by 50% when creating the world’s first exhaust emission reduction system to be certified by CARB for the PZEV standard.
“MathWorks tools have been essential for reducing our development time and costs, while enabling us to deliver a high-quality product,” says Mr. Kakizaki.
Nissan used MATLAB, Simulink, and Stateflow to develop models of their emission control strategy. These models became the main specification for the system, which engineers reused throughout the development process.
Using Simulink, engineers first created a plant model of the engine to validate designs and refine the PZEV emission control strategy for the 2000 Nissan Sentra CA.
“Simulink enabled us to perform simulations early in the design process,” says Mr. Kakizaki. “This helped us quickly validate our design ideas and refine our control strategies.”
Kakizaki’s team validated their algorithms on real engine hardware and met the emission requirements. They then began implementing their design and developing software.
For the third-generation emission control, Nissan used Simulink to implement a “Sliding Mode Control” strategy—one of the latest advancements in emission control. Nissan applied this strategy to their Maxima, Quest, Murano, Z-car, and Titan trucks, and was able to reduce the number of sensors without losing any control capability.
“The capabilities in Simulink helped us to move an advanced control strategy like Sliding Mode Control from research to implementation in production vehicles,” says Mr. Kakizaki.
Nissan is currently improving testing and verification by applying a concept they call “model-based testing.” By generating test cases from Simulink models and comparing the results against the actual implementation in hardware, model-based testing will reduce program verification time and software quality quantification efforts. Nissan is working with MathWorks Connections Partner Reactive Systems, on the development of this technology.
“Evolving Model-Based Design further into the testing phase will provide substantial improvements to the overall efficiency of our development process,” notes Mr. Kakizaki.