Chery Enables In-House Development of Engine Management System Software with Model-Based Design

“When working with third-party suppliers, it is difficult to change the schedule, add new functionality, and resolve after-sales problems. Model-Based Design is more efficient. It lowers costs, and gives us the flexibility to allocate resources and finish development as fast as possible.”

Challenge

Bring development of engine management system software in-house to decrease development cost and accelerate the development process

Solution

Use Model-Based Design to model, simulate, test, and generate production code for EMS software

Results

  • Cost savings of nearly $2 million per year
  • 60% of control design reused, halving development time
  • 200,000 lines of defect-free code generated
Chery engine powered by in-house developed EMS software.

Chery Automobile Co., Ltd. is among China’s largest automobile manufacturers in vehicles produced, and the country’s largest exporter of passenger cars. With its production volume and diverse customer base, Chery management realizes that engine management system (EMS) software is key to meeting feature function requirements and engine delivery schedules. To lower maintenance costs and control delivery schedules, Chery develops its own EMS software while sourcing the EMS hardware from its suppliers.

When Chery began the move to in-house EMS development, no other domestic automobile company in China had built its own EMS software. To enable this move, Chery adopted Model-Based Design. EMS units developed in-house with Model-Based Design have been in high-volume production since 2009, and the company has developed two generations of its EMS technology.

“Model-Based Design enabled us to ramp up rapidly,” says Keguang Qi, project manager at Chery. “MathWorks tools for Model-Based Design are easy to use, understand, and operate. That was important for our engineers, who had little previous experience in production development of EMS software, because we could model our systems, verify them with hardware-in-the-loop testing, and then generate highly efficient code. ”

Challenge

Chery sought to achieve volume production of EMS software developed in-house—a critical first step in lowering costs and enabling rapid development of new functionality to meet changing market demands.

Chery engineers were experts in engine systems but had little practical expertise in C language programming for production EMS systems. To meet its long-term business goals, Chery needed a development process and tools that the engineering group could learn quickly. Specifically, they sought tools with support for modeling and simulation, comprehensive hardware-in-the-loop (HIL) testing, and production code generation.

Solution

Chery adopted Model-Based Design and engaged MathWorks engineers to help the team develop proficiency in MATLAB® and Simulink®.

The Chery team defined system requirements in Microsoft® Word. Based on these requirements, they developed an EMS control model using Simulink and Stateflow®.

Using Simulink Check™ and Requirements Toolbox™, the team established bidirectional links between requirements in Word and the model elements in Simulink that implemented the requirements.

As they developed their model, the engineers relied on the Model Advisor in Simulink to check compliance with Chery modeling standards, which are based on MathWorks Automotive Advisory Board (MAAB) guidelines.

Working in Simulink, the team created an engine plant model and combined it with their control model to create a system model for closed-loop simulations.

Using Simulink Coder™, the team generated code from the plant model and deployed it to dSPACE hardware in preparation for HIL tests.

The engineers used Embedded Coder® and Fixed-Point Designer™ to generate more than 200,000 lines of code for the fixed-point PowerPC® microcontroller. The team performed HIL testing, verified the test results against requirements, and used the test results to refine their EMS model.

Chery produced more than 600,000 units of the first-generation EMS, designed for use with a mechanical throttle. This generation is installed in several passenger car lines, including the Chery QQ. A second-generation EMS, designed for an electronic throttle, variable valve timing, and a variable intake system, is also in production. Both generations were completed on schedule.

Chery is now exporting their engine with EMS software to vehicle and off-road machine manufacturers overseas.

Results

  • Cost savings of nearly $2 million per year. “With Model-Based Design we mastered EMS technology on our own, and are no longer dependent on suppliers,” says Qi. “As a result we lowered per-unit EMS costs by more than 10%. At production scale, this has saved Chery almost $2 million a year.”

  • 60% of control design reused, halving development time. “We reused 60% of our Simulink design from the first-generation EMS in our second-generation product,” says Qi. “Model reuse reduced system development time on the second generation by about 50%.”

  • 200,000 lines of defect-free code generated. “We saved development time by generating 200,000 lines of production code from our Simulink model with Embedded Coder,” Qi says. “The generated code is highly efficient, and we have not found any bugs in it.”