A driver behavior study by Cruden has revealed new findings in the development of haptic shared-control lane-change systems in cars and their performance and interaction with drivers, passengers and other road users. Currently, no haptic shared-control systems that assist the driver in finding the right path for lane-changing maneuvers are in production, whereby ADAS and human inputs work together via forces on the steering wheel.
Systems found on today’s cars either work by giving haptic feedback through the steering wheel when a car leaves a lane without indicating or through sound and blind spot warnings through to full autonomous lane-change functions.
The research, by Christiaan Koppel, presented at the recent Driving Simulator Conference (DSC 2019) in Strasbourg, uncovered a fundamental shift in the approach to testing and developing ADAS systems, whereby a driving simulator is used as a tool to help develop ADAS holistically, and more crucially, incorporating the interaction with a human operator, versus simply validating the system in isolation. Essentially, the system becomes an extension of the EPAS (Electric Power Assisted Steering) system and driver and machine execute the maneuver together.
For the purposes of the study, Cruden’s white paper research analyzed the inter- and intra-driver variability in lane change behavior of lane-change systems on a vehicle. The control experiment begins by first understanding the variability in human behavior of changing lanes using a non-ADAS equipped vehicle on a state-of-the-art Cruden six-axis driving simulator.
The reactions and behaviours of 12 participants in executing a lane-change manoeuvre in different scenarios was observed. Driver input and interaction with the car (steering and acceleration) as well as the effect of different environmental factors such as traffic density were measured, recorded and analysed.
Thanks to Cruden’s advanced Panthera simulator software coupled with a moving base simulator, the installation was able to seamlessly integrate a number of external programs and modelling graphics that delivered a high-fidelity, low-latency simulation experience
Once the control data was recorded the team of ADAS engineers and Cruden’s own senior engineers were able to gain a better understanding of human lane-change behaviour in terms of lane-change duration, steering behaviour and vehicle trajectories. This then informed the testing procedure of ADAS-equipped vehicle simulations and their effectiveness in executing the lane-change manoeuvres in tandem with the drivers, but more importantly, documenting the manner in which it completed the task and confidence it inspired – or perhaps did not inspire – on its human operator.
Haptic shared-control systems can help solve well-known issues attached to fully autonomous features where users either abuse or misuse it, whereas with this technology the driver is always in the loop.
Jelle van Doornik, one of the lead researchers and Product Manager, ADAS at Cruden, said: “To make the next generation of ADAS acceptable, it is essential to first focus on the different types of human drivers and how they behave in a variety of circumstances in as close to a real-life situation as possible. Using a haptic shared-control steering system has the benefit of keeping the driver in charge, but with support from a sensory system that provide an additional level of control and safety.
“Significant numbers of drivers can be analysed using a driving simulator, with scenarios categorised by use case. Here, the simulator is used to specify the ADAS requirement, not just validate it. The study extracts the set of requirements, determining what the ADAS system must do and how it must be designed to assist the driver most effectively, comfortably and receptively. This is a new approach.”
In conclusion, to design future intelligent and lane-change systems that perform and assess prevailing road conditions just like a human would, greater emphasis, as well as studies on steering responses, angles and steering duration, is required.
Human-like lane change trajectories should be implemented and tested in lane change support systems in order to assess whether individualized lane change assistance systems indeed increase acceptance by drivers.
Intelligent lane-changing and shared-control haptic systems are the next level of ADAS currently under development that will shortly make its way to production vehicles. The value in these systems lies in the interaction between it and the operator and Cruden’s platform provides the engineering freedom to develop these future systems holistically.
This study was also the subject of an article in Issue 12 (2019) of ATZ magazine (page 62): http://emag.springerprofessional.de/public/data/atz-worldwide/Issue_12–2019/index.php?token=05312929
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