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Accelerating Hardware-in-the-Loop Testing

Published: April 30, 2014

Jeff Warra
Technical Specialist

It’s an exciting time to be an embedded software or systems engineer because the technical developments driven by embedded software are increasing at a great pace. The automotive industry is advancing safety critical and emissions technologies every day. However, this rapid advancement of technology − with more and more sensors in vehicles and increasing interdependence of systems − can lead to tremendous challenges in effective testing. 

That’s why I am excited to talk about two new aspects of hardware-in-the-loop (HIL) testing that are helping address today’s testing needs:

  • Use of virtual electronic control units (V-ECUs) in HIL testing, and;
  • The combination of HIL and mechanical test environments to achieve advanced calibration.

Finding errors earlier in the development process with virtual validation

Proper testing of electronic vehicle systems takes time.  The environment has to be set up to ensure that the test bed is capable of validating all of the features and functionalities of the overall system.  The increased interdependence of subsystems, and the reality that required electronic control units (ECU) are typically not available at the same time can result in the loss of critical time in product development due to delays in testing.

dSPACE was able to foresee this need and developed VEOS, a platform for V-ECU testing that helps augment a company’s testing capabilities. With VEOS, V-ECUs can be created for all software components of an ECU, together with the operating system, diagnostics event manager, memory management etc. The V-ECU represents a more realistic ECU software functionality than a simple functional model of the controller, commonly termed as soft ECU. With VEOS, users can create a complete virtual environment for testing. The V-ECUs defined in this early stage of development can then be reused for real-time testing with the dSPACE SCALEXIO HIL system.

Being able to mix virtual and real components during HIL testing helps accelerate bench testing, ensuring that issues are caught early in the development process and saving time. Once the real ECUs become available, customers can switch out the virtual ECUs and run the same tests that were developed with the virtual ECU with the real ECU.   

Having the right mix of real and virtual components enables engineers cut development time and costs associated with developing the innovations of tomorrow, such as highly complex systems like mixed mode hybrid transmission, electric power steering and active damping etc.  

Combining mechanical and simulation test environments for advanced calibration

A paradigm shift is happening right now where more and more calibration development work is being done using mechanical test bed environments coupled with high-fidelity models running on HIL environments. This type of setup helps speed up analysis of longitudinal vibrations for shake, tip and kick down jerk, taking into account the elastics effects of the vehicle body while trying to improve driver comfort.  

A dSPACE HIL simulator gives you the ability to drive the signals to the ECUs and record responses of the mechanical test bed actuators, sensors and signals. Having one systems control and monitor all signals with a single time base gives customers the ability to quickly analyze the system response.  And by using dSPACE ModelDesk, engineers can change calibrations on the fly without having to recompile the models. This allows calibration engineers to repeatedly simulate precise longitudinal vehicle dynamic maneuvers enabling better comparisons of calibration changes. 

HIL simulation testing can outshine real world testing because a real-time simulation computer drives the inputs vs. a human driver performing the same maneuvers on a test track. This allows your engineers to focus on the analysis of the signals to better understand the dynamic behaviors of bending and torsional frequency of the vehicle body, rather than focus on driving the test vehicle. By being able to run exactly the same maneuvers, engineers can focus on system behavior without having to deal with the variability of test conditions. This helps reduce development times and cuts costs considerably. 

The combination of mechanical test beds and HIL technologies should deliver the next generation revolutionary algorithms and ideas for embedded systems much faster than ever before.

With advanced technology from dSPACE, the inventions of tomorrow are being developed today. Is your test lab ready for the challenge?

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