Human Machine Interface (HMI)
Human Machine Interface (HMI)
How much information is too much?
New information technology is making it technically possible to supply drivers with virtually unlimited amounts of information while they drive. But there is an obvious risk that the increasing volume of information will pose a threat to safety - in other words, the interplay between the driver, the machine and the traffic environment will be compromised.
To ensure that additional information designed to aid the driver does not defeat its purpose, it is extremely important that it be presented in a way that matches the driver's needs and abilities. This is the starting point for Volvo Car Corporation's research within the field of Human Machine Interface (HMI).
Volvo SCC - a valuable test tool
The Volvo Safety Concept Car (SCC) is a prototype for testing different ways of creating a user-friendly interface. Ideally, the driver should perceive the information as a source of support and not as a burden. As different drivers may have different information needs, they should be able to control the amount of information and the way it is presented.
"Since we presented the Volvo SCC at the Detroit motor show, I have often been asked whether all this information and warning technology will not be too much for the average driver. My answer? Yes, of course it is possible that there can be too much information. Evaluating this is one of the main challenges for our research," says Christer Gustafsson, safety engineer at Volvo Cars.
Focus on the driver
The objective of the research is to find methods for measuring how new information impacts the driver's ability to drive safely, creating the basis for developing new user interfaces and their implementation.
"In this context, it's incredibly important not to throw oneself into an unplanned, galloping technology development process. It is not a question of creating what is technologically feasible but of building what is desirable from the point of view of the driver and safety," explains Gustafsson.
What information enhances safety?
The challenges are in two areas.
- How should the information be presented? This includes the design of displays and their position in the car to make them user-friendly.
- How should the information be sorted? If there is a heavy flow of information, can the car help the driver by prioritizing certain information and delaying other information?
The Volvo SCC distinguishes between different types of information. The information from the car to the driver is shown on a large display in the instrument panel. This includes camera images and warnings related to the driving task, in addition to trip data. Activity initiated by the driver and not directly related to the driving task, such as controlling the audio unit or the phone, is presented on a display on the upper part of the centre console.
Prioritizing information
Prioritizing driver information is also the nucleus of another research and development project called Intelligent Driver Information Manager (IDIM).
Using a number of driving parameters such as movement of the steering wheel, throttle and so on, IDIM can sense when the driver has to focus on driving and when any distraction -- in the form of a phone call, a voice or other message - could jeopardize driving safety.
IDIM then gives driving safety top priority and delays incoming phone calls or messages so that they are presented later, when the driving situation is less demanding.
"IDIM is an excellent illustration of the way information can be sorted and prioritized to make driving safer. The system can also improve the potential for the safe use of technology such as the phone and other messaging systems. An integrated phone in combination with IDIM creates totally different opportunities for telephony in cars than a phone lying loose on the passenger seat," says Gustafsson.
Rather than inhibiting communication and interaction with in-car systems while driving, IDIM makes it possible for the driver to fulfil his/her communication needs while maintaining driving safety.
Techniques for measuring driver distraction
Volvo Cars has also tackled the challenge of measuring the way different kinds of information affect driver attention.
Currently, several methods are available for measuring mental workload. These methods can be divided into three groups: subjective measurements, performance measurements and physiological measurements.
Peripheral Detection Task (PDT), a performance measurement, has been chosen for further studies. PDT is used to register changes in peripheral vision. Increasing mental workload is associated with a reduction in the driver's visual field.
An experiment has been performed to examine whether PDT discriminates between different levels of mental workload for the driver. Twenty-four subjects participated in an on-road experiment.
A navigation system was used to provide the drivers with route information visually, verbally or both visually and verbally together. A memorized route was used as baseline. The drivers' PDT performance was measured and the results show that PDT is sensitive to mental workload compared with other measurement methods. This makes PDT promising as an evaluation tool for new in-vehicle information systems.
Ford investing heavily in HMI research
Volvo Cars' parent company, the Ford Motor Company, has opened a new high-tech US$10 million driving simulator laboratory called VIRTTEX to study driver work load and distraction issues related to new in-vehicle electronic devices. Ford plans to use PDT in the VIRTTEX as one of its evaluation tools.
The new facility allows researchers to measure a driver's ability to cope with common traffic situations while using cellular phones, navigation systems and other in-car equipment.
This simulator is the Ford Motor Company's first full-scale, moving-base driving simulator and it is the most capable device of its kind currently owned by any automotive manufacturer in North America.
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Information:
Lisa Graham
Volvo Cars of Canada Ltd.
(416)490-5834
lgraha11@volvocars.com
Doug Mepham
MacDonald & Co.
1-877-975-1572
doug.mepham@sympatico.ca