Today’s automobiles have as much in common with advanced consumer electronics as they do transportation. In fact, according to Car & Driver magazine, your car is the most advanced electronic device you own, with high-end luxury vehicles typically sporting more than 100 electronic control units (ECUs).
Safe and reliable operation of the vehicle is, of course, the primary objective during electronic systems confirmation testing - But there is more at stake here for automotive manufacturers. A subset of a vehicle’s computing power directly affects its drivability – its vehicle dynamics fingerprint and subjective character, which are crucial to brand identity and value perception. Over many years, companies like Ford and BMW (“Sheer Driving Pleasure”) have anchored their automotive brand identity on the way their cars drive. For these and many other manufacturers it is crucial that the myriad electronic systems placed between the driver and the road do not detract from the actual driving experience.
As a technical manager, how do you stay in control of a large number of ECUs while delivering safe operation, preserving your brand character, and meeting your schedule? In engineering terms, the challenge for automotive development teams often boils down to how to develop more experiments and the corresponding Design of Experiments (DOE) to keep pace with on-board systems and interaction complexities.
DOEs are traditionally managed offline in order to reduce multi-factor test matrices down to more manageable, realizable test programs. However, the increases in vehicle complexity can push the number of must-test cases beyond allowable time and resource limits. One risk is that surface maps derived from DOE may literally be “rough around the edges,” when it is often the edges (limit cases, infrequent occurrences, etc.) that may be of particular interest. Still another risk is that brand identity is lost in the cold, mechanical process of bringing increasingly complex new products into the marketplace.
Let’s consider the evaluation of a new electric power assisted steering (EPAS) system as a brief example. Suppose we are on a highway on-ramp and the EPAS suddenly loses its sense of vehicle speed due to a line voltage drop. The system switches to its failsafe mode, where the driver has mechanical control but the now-unassisted steering suddenly becomes “heavy.” How does a real person react? Do the reactions of a real person trigger the interaction of other on-board systems such as electronic stability control (ESC)? Is the ESC operating correctly or it also in failsafe mode? What if all this is happening as the vehicle traverses a patch of ice? How might EPAS tuning settings born from these explorations of extremes fold back into a driver’s impression of steering feel during normal driving situations? And so on.
Even More Experiments – But with a Twist
In order to refine EPAS settings in the context of how they might be perceived by real drivers, one might ask if there some way to execute a DOE (or sub-map thereof) from the perspective of brand character? In an offline sense, the answer may, unfortunately, be no. But there is still hope. One answer may be to conduct more rather than fewer experiments…But “on-line” instead of offline, using Driver-in-the-Loop (DIL) simulators.
Since DIL simulator experiments take place in a controlled, repeatable lab environment, and since so many changes can be accomplished easily with a touch of a keypad in the simulator control room, the EPAS questions posed above (and many more) can be answered with an almost staggering reliability and efficiency. A vehicle dynamics class DIL simulator enables engineers to investigate almost everything - including extreme situations – without endangering people or expensive prototype vehicles, by actually engaging expert or inexperienced drivers at early stages in (and throughout) a vehicle’s development.
Away from proving grounds and test tracks, but squarely in the midst of new electronic and ADAS system developments, Ansible Motion’s vehicle dynamics DIL simulators are currently enabling vehicle constructors around the world to execute their DOEs while including the human element. This increased efficiency and connectivity with real drivers allows design teams to meet their functional, safety and reliability goals for on-board systems, and it provisions the opportunity to preserve and refine brand identity.
To learn more about how vehicle dynamics class DIL simulators can accommodate the evaluation of on-board electronic systems, download our FREE eBook, “Looking down the road: Harnessing the benefits of driving simulator technology”: