Traditionally, bench testing of electronic control unit (ECU) software relies heavily on the use of static simulators. They are simple to set up and low cost. However, static simulators lack the programmability, I/O scalability, and the support for new sensor and actuator interfaces. They do not have standard and extensive support for test automation, which is critical for achieving a high degree of test case coverage and regression testing. Lastly, they are unable to take advantage of plant models for closed-loop testing. In short, with the increasingly sophisticated ECU technologies, static simulators can no longer keep pace with the testing requirements that an ECU development team must meet.
In this paper, Opal-RT and Delphi present the development of a new modular bench top simulator designed to replace the static simulators currently in use. The first part of the paper discusses the overall architecture of the system and the design decisions made to reduce system cost so the resulting simulator can be deployed in large numbers. The second part of the paper describes each of the following major functional areas of the system, including rationales behind the design and its benefit observed from the initial deployment.
The third and the last part of the paper details the system's support for two advanced features, closed-loop simulation and dynamic software verification. The first, closed-loop simulation, was made possible by controlling the simulator using a model created using a commercially available modeling program. By running a model, the simulator is then able to support the full range of test activities from open-loop functional checkout to closed-loop system validation. This model-based test environment also makes it possible for test engineers to adapt simulators for specific test needs by editing the model using a commercially available modeling program. The second, dynamic software verification, allows a simulator to access ECU's internal variables through the CAN Calibration Protocol (CCP) and IEEE ISTO-5001NEXUS interface for “whitebox” verification.