Knowledge Base
In search of perfect harmony: HMI testing in a driving simulator
Written by
Cruden
Published on
December 20, 2022

Developing the human-machine relationship in a simulator is a great way to build a seamless, intuitive interaction between the driver and ADAS or infotainment technologies

With the proliferation of onboard systems to enhance occupant safety and increasingly complex infotainment setups to satisfy the consumer’s desire for connectivity on the move, it has never been more important to evaluate the human-machine interfaces (HMI) in new vehicles.

Maximum scores in consumer safety test programs like EuroNCAP demand additional ADAS technologies as standard equipment. But it’s not sufficient for such systems to be merely functional. Unless they are well integrated into the driving experience – easy to control and un-intrusive in operation – drivers are known to switch them off in frustration, limiting their safety benefit. Infotainment systems meanwhile are among the most sought-after features among vehicle buyers but come with a heightened risk of driver distraction if the ergonomics, screen-flow or graphics are ill thought-out.

Driver-in-the-loop (DIL) simulators are an excellent way to develop HMI. Evaluating new functions in a dynamic simulator is a far more immersive experience than testing them in isolation or on a desktop or other static setup. Operating new systems or technologies while simultaneously performing the primary task of driving a car, is a whole different experience, and results in better and more relevant feedback on what does and does not work.

“Take a rental car as an example,” says Dennis Marcus, Cruden’s commercial manager for automotive and motorsport. “If the car is new to you then the first few kilometers can be very dangerous as you try to figure stuff out. If configuring the navigation system, connecting your phone to Apple CarPlay or even switching off an ADAS system isn’t straightforward, the driver may put themselves in a dangerous position.”

About 40% of Cruden’s customers use their simulators to test HMI, often alongside other workstreams such as vehicle dynamics development. In some cases, the third-party tool integration requirements might look similar for both applications: dSPACE or other hard real-time systems for an ADAS controller or infotainment ECU, for example.

But since it’s the driver’s interaction with the system that’s being tested, rather than the vehicle’s performance, other commonly integrated tools are less important. The car’s ride and handling is not being assessed, so instead of a physics-based, real-time vehicle dynamics model, many of Cruden’s customers conduct HMI experiments with a generic vehicle model that is part of the simulator’s core Panthera software. Similarly, the motion system isn’t required to deliver the utmost degree of fidelity. It’s enough for the driver to feel they’re in a car, immersed in a realistic driving environment.

Some customers prefer to mount a full chassis mockup on the simulator platform for even greater immersion in HMI experiments, but in many cases, a flexible mockup made from ITEM profiles – reconfigurable sections of extruded aluminium – enables new dashboard or steering column prototypes to be easily added, modified and replaced.

There’s further flexibility in Cruden’s approach to HMI testing. In a theme common to all its simulator applications, the company is agnostic to the engineering tools the customer prefers to use. That extends to working with the actual instrument panels under evaluation, rather than making the display part of the simulation software.

With driver distraction a growing problem and automation levels on the rise, customers are increasingly using their simulators to test eye-tracking systems, facial expression monitoring and the driver’s response to an attention alert. Here, the technical development of HMI by OEMs and suppliers connects with HMI-related work that Cruden facilitates as part of human factors research at academic institutions, such as the University of Michigan-Dearborn.

Human factors investigations are often undertaken by biologists, physiologists and psychologists, rather than by the automotive engineers who might work with simulators in other applications. Cruden meets their needs by integrating openly with whichever biometric tools they require, such as the iMotions data acquisition software that supports many types of biometric sensors, and by providing simulators that are easily managed by scientists from different fields.

“A computer is a tool that needs to work for them, instead of them working for the tool,” says Marcus. Often biometric researchers are hesitant to run their experiments on full blown driving simulators, preferring a more simple set-up that is easier to operate. What we do differently is enable them to do the research with a standard, integrated vehicle model and a motion system that is controlled automatically. We can set up the Panthera software in a way that provides a realistic driving experience but still makes it easy to configure, start and stop an experiment. They don’t need to be a simulator engineer to run a test.”

For more information on the use of biometrics with simulators in automotive, this iMotions blog is interesting. If you scroll down to the end, you can read about the use of a Cruden simulator at the University of Michigan’s Dearborn’s Lab.

HMI’s position as a gateway between engineers on one side and more human behavior-related research on the other also applies to marketing departments, for example in the evaluation of user graphics to communicate brand values and heritage, or reinforce in the mind of the driver the impact of a change in drive mode.

In all cases, a driving simulator provides an unmatched means of assessing at an early stage a driver’s interaction with, and control of, a safety or infotainment function – in an environment where the primary task, driving the vehicle, is never a secondary concern.

For more information, please contact Dennis Marcus via d.marcus@cruden.com or on +31 20 707 4646.

Links to subsequent articles will be added below as they are published.

View all articles in our Tool Integration series of articles: here.

Article 1: Driving simulator and third-party engineering tool integration

Article 2: Four wheels good: Vehicle model integration for dynamics and more

Article 3: Hard decisions made easier: Hardware-in-the-Loop testing with DIL simulation

Article 5: New Panthera Corebox is at the heart of tool integration

Article 6: Standard interfaces for non-standard simulators

Article 7: Perfect harmony: The driving simulator as a virtual OEM

Article 8: Tool Integrations - Data acquisition