Car HUD:
Research & Design
I worked as an undergraduate research assistant on this research project during my undergraduate career at Purdue University. In this position, I conducted literature reviews and led the visual design work. The research project was not completed during my tenure. However, the work that I completed during this time led me to win third place in my college at Purdue's Undergraduate Research Symposium.
My Contribution
Abstract
The interface design of In-Vehicle information system (IVIS) is an important research topic in the area of driving behavior and safety. Most cars currently have a head-down display (HDD). However, research is finding that these are unsafe and cause drivers to look away from the road for a period of time. As car head-up displays (HUD) become more common, designing a more prominent and useful display is important. This contribution of this research is to prove which design elements and principles are essential in a safe and usable car HUD.
Background
HUDs originally began for use in aircraft in the 1970s. However, in the were introduced to automobile production in 19884. Originally, HUDs were made using cathode ray tubes (CRT) and have recently began to be made using liquid crystal displays (LCD) and light emitting diodes (LEDs).
Head-up displays aim to decrease eye movement and reduce the amount of time the driver’s eyes are off of the road by displaying important informations on the windshield in the drivers focal point. HUDs are generally used in vehicles to show speed, malfunction warnings, media settings, and more.
There is a difficulty designing HUD interfaces for automobiles comparing it to that of aircrafts. Aircrafts have a rather consistent background in comparison to vehicles. Vehicles have backgrounds that are constantly changing from different road conditions, levels of sunlights, pedestrians, signage, and more.
Designing for HUD has become a very detailed process requiring research, testing, and concepts. The design of HUD has to be safe, usable, aesthetic, and unobtrusive. Displays are continuing to grow in cars and expand in technology and HUD will be the next major technology to be in most cars.
The Users
Because HUDs have the ability to be used in any car, we wanted a wide variety of users. We want this design to be usable and safe for any age, height, gender, and more. We set our users as Males and Females, aged 18-60.
Element Research
To design the interface of the HUD, research of common HUD design principles was conducted. 5 different Interfaces were designed. Specific elements had to be included, as these elements were proven to be the most understandable in previous research.
The speed limit sign as seen in Figure 1 is best for speed warning. For navigation, the triangle car maker is more effective especially when paired with a simplified map as seen in Figure 2. Additionally, for any type of menu, a classic and linear type menu is the best option as seen in Figure 3. From this, various interfaces were designed.
DESIGN
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Initial Designs
Figure 4 was designed with a classic interface in mind. It is a flat panel that would be located in front of the driver. Figure 5 was designed also to be classic. However, instead of a menu, there are different phases that you can scroll through. For example, the fuel panel is shown above. Figure 6 was designed to be an augmented reality HUD. The boomerang-style arrows for the navigation would lay on the road. Additionally, it is made in perspective for the focal point of the driver. Additionally, the panel style is different. This would display in a different part of the windshield. Figure 7 was designed very similar to Figure 6, However, the red line will lay flat on the road. Additionally, it uses a classic style panel.
Iteration
We interviewed some users and found that some of the drivers don't want to see their exact speed, they just want to make sure they aren't over the speed limit. This spoke to our team and made us construct two more designs that show speed as a range bar and not a number. This way, the user's view is not taken over by large text.
Experiment
For this study, a driving simulator will be used to test two aspects of the designs: usability and driving safety. The two test will be conducted simultaneously.
Usability Test
To test the usability of the design, the drivers will be given a scenario and two tasks: speed monitoring and navigation monitoring.
In the speed monitoring task, the drivers will be asked what their current speed is and what is the speed limit? Additionally, for the navigation monitoring, we will ask the drivers what their next direction is and how much longer until they need to make an action? We will test to see the time it took the driver to complete each task.
Also, questions about the driver's experience will be asked to see the driver’s emotion toward the design. This will allow us to collect qualitative data and really get an insight to how our testers feel.
Speed Monitoring
In the speed monitoring task, drivers will be asked to drive straight as seen in figure 3. They will be asked to stay within the speed range of 50-55. We want to test this to see how well drivers are able to maintain their speed using an HUD. During this test, driver safety will be tested as well. This means eye tracker data will be collected as well as ECG data.
Navigation Monitoring
In the navigation monitoring task, drivers will be asked to drive according to the directions on their HUD. It will feature curves as seen in figure 10. They will be timed to see response times. We want to test this to see how easy it is for drivers to use GPS on their HUD. During this test, driver safety will be tested as well. This means eye tracker data will be collected as well as ECG data.
Questionaire
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Which of the following design do you feel was easier to understand?
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Did you find that you have to shift your focus to view the HUD?
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Did you feel any of these are very unsafe?
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What did you like about each one?
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What did you dislike about each one?
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What would you change about this experience?
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Any other suggestions you might have?
Driving Safety Test
We will test driving safety by testing mean number of glances, total glance time, speed variation, and heart rate/ECG data. This will be made possible through the use of eye tracker technology and heart rate monitors. We will use eye tracking data to detect where it is our users are looking, how long they are looking, and their focal point on the road. Speed variation will be tracked by recording the tester’s seed throughout the test. The average speed and standard deviation will be calculated using this data. Additionally, we will use the ECG data to detect excited or nervous times tracking. data to detect where it is our users are looking, how long they are looking, and their focal point on the road.
Participants
There will be 24 participants. 16 male and 8 female. Each participant will be at least 18 years old, have a driver’s license, and competent vision. They will be split into 3 groups. Group A will consist of 8 males, Group B will consist of 8 males, and Group C will consist of 8 females. A visual can be seen in figure 8. This will allow us to compare data between different ages without a gender variable. Then we can include the gender variable and compare the outcomes. Each will test each design and complete all 3 tasks. Below is a visual to aid in the understanding of the grouping.
To Be Continued
I am very thankful to have worked on such an amazing project. This research is ongoing and has yet to be finished. However, I will not return to this project. Special thanks to Purdue Polytechnic Institue, Dr. Yingjie Chen, and Rui Li.
My Poster
