Today’s vehicles contain 40 to over 100 Electronic Control Units (ECUs) which must be functionally integrated with the car and its environment. Introducing changes, such as functional ECU integration or software updates, must be rigorously tested to ensure the safety and performance of the vehicle.
Hardware-in-the-loop (HIL) simulation and testbench tools provide the necessary control environment to test these increasingly complex real-time embedded systems of systems. Manufacturers typically use multiple testbench platforms from different vendors. As a HIL-Bus platform, Connext DDS can integrate the functionality of multiple existing HIL sub-systems and enable testing of modular best-in-class test ecosystems. This data-driven approach reduces the complexity of the testbench, making it easier to integrate hardware and software products from multiple vendors without coding changes. It is future proof and extensible, allowing for model extensions and option configurations for alternative components supplied by different vendors.
Connext DDS can test multiple and redundant units in parallel, with automatic failover. It is highly-scalable to accommodate redundancy and parallel nodes. Plug and play capabilities allow developers to add components with assured interoperability, backed up and enforced by the Connext DDS data model. Test data is easily monitored through content filtering and exception-finding features.
The Connext DDS framework allows for real and simulated testing to be done across a variety of domains. When combined with the RTI Record and Replay service, Connext DDS becomes a powerful system analysis and development tool to simulate system behavior in many scenarios.
Audi Modular Testing
Quality car maker Audi emphasizes quality and advanced technology in its best-selling vehicles. To achieve these goals, Audi is building a new, state-of-the-art hardware in the loop (HIL) simulator architecture based on Connext DDS. The simulator is fitted with electronic panels, each containing one Electronic Control Unit (ECU). A modern car may have 500 ECUs and over 100 processors.
Everything in the car with a wire is mounted on an ECU panel. These include engine control with fuel injectors and spark plugs, the driver console, Infotainment, heated seats, anti lock brakes, active suspension and more. The goal is to reproduce all the electrical systems in the vehicle and make sure they work together. The simulation must run fast enough to duplicate the real-time signals in an actual moving vehicle. When a test runs, each module is represented as either the actual hardware or a software simulation. If actual hardware fails during the simulation, the software simulation takes over so the test can continue.
The system is flexible and scales according to testing requirements. Audi's system simulates the entire vehicle as well as multiple cars interacting with each other and with the road infrastructure. ECUs can be exchanged to represent different vehicle options and different vehicles. Audi's test architecture integrates simulation test products from many manufacturers. It implements two DDS domains: one for very fast simulation, and one to provide data to control the system and share data with storage systems and operators. Formerly, this was done using a test rig server to shuttle data. With Connext DDS, every device can directly be connected to the databus. Audi plans to combine multiple simulation vendors' systems into a single network through the easy integration capabilities of Connext DDS.
For complete details, view A New Architecture for Automotive Hardware-in-the-Loop Test (courtesy ATZ elektronik).