Data Injection and Partial ECUSimulation : Modifying CAN and UART messages for testing of ECUs

Sammanfattning: Modern vehicles contain lots of Electronic Control Units (ECUs) that control different systems. They communicate with each other and other components through communication interfaces such as Controller Area Network (CAN) and Local Interconnect Network (LIN) buses or simple Universal Asynchronous Receiver/Transmitter (UART) interfaces. Testing of ECUs is an important part of the vehicle development process. Testing can be performed in multiple levels, where ECUs are first tested individually and communication with other ECUs is simulated. At a later stage, multiple ECUs are integrated and communicate autonomously with each other. Testing at a lower abstraction level with simulated systems gives the tester a lot more control and ability to test edge cases while testing at a higher abstraction level with real systems is more realistic. This thesis project investigates a new testing concept, where ECUs are partially simulated by modifying CAN messages that are sent between connected ECUs in real time to answer the research question ”Can better or easier testing of ECUs be enabled by combining concepts and tools from different levels of testing?”. This is done by developing two different testing tool prototypes. One based around a computer, the CANoe software and a Vector CAN interface. One consisting of an embedded system with a simple Human-Machine Interface (HMI). A method for minimizing delay for data injection in a UART interface using a Multiplexer (MUX) is also proposed, implemented and tested. Prototypes are developed and tested with both generated input data and with real systems at Scania. Developers and testers at Scania are also interviewed to get their opinions on the prototypes, the general concept and future use cases. The results indicate that the partial simulation concept has potential to be useful and lead to better or easier testing as well as development of ECUs. Some future work is suggested for further development of the prototypes as well as for additional research into the subject.