Smart Cockpit HMI Design and Driving Safety

Intelligent cockpit design innovations bring users a rich experience on the one hand, but on the other hand, they pose a challenge to driving safety. Firstly, in terms of configuration, the replacement of physical buttons by a large screen reduces the possibility of blind operation by the driver

When a driver looks down to check the information on the dashboard, the time consumed is 1~3 seconds. Taking the average speed of 60km/h on city roads as a basis for calculation, 1 second of attention away from the road is equivalent to 17 meters of driving with eyes closed.

Whether the screen content is clear, whether the interaction is simple and direct, whether the equipment response time is short enough, all of these will affect the operation time, thus affecting the safety of driving, the rich applications on the screen to the car driver and passenger to provide a variety of entertainment, life possibilities, the passenger can sing K, watch dramas, play games, but too much information may lead to information overload, so that the driver’s response to the unexpected events is insufficient.

The diversity of driving tasks also poses a challenge to driving safety. Driving scenarios have several parameters such as natural environment, vehicle condition, road condition, driver’s driving level, emergency situation, etc., and each parameter can be combined together to get an endless number of driving scenarios. Once the system lacks the prediction of a certain scenario, it may pose a threat to driving safety.

Currently, intelligent cockpits address the challenge of driving safety in several ways. the application of HUD reduces distractions to a certain extent, allowing drivers to obtain important information such as speed, navigation, etc. without taking their eyes off the road. Multi-mode interaction makes up for the lack of large-screen operation and reduces the possibility of distraction through voice, vibration, and gestures. Improvements in car chips and arithmetic power make the system smoother and more responsive. The assisted driving system continuously learns new scenarios through big data to avoid danger when in new scenarios.

In addition, limiting driver behavior in the driving state is also a way to address driving safety challenges. The U.S. National Road Traffic Safety Administration has formulated guidelines for in-vehicle electronic devices, which provide appropriate guidance on the safety of in-vehicle electronic device interaction behavior, using the following requirements to regulate driving behavior and guide cockpit design, which we can also refer to.

Requirements of principle

(1) The driver’s eyes should remain focused on the road ahead.

(2) The driver should ensure that at least one hand is on the steering wheel while performing a secondary task (whether performing a driving-related task or an unrelated task).

(3) The distraction caused by any secondary task performed while driving should not exceed the distraction associated with the baseline reference task (manual radio tuning).

(4) Any task performed by the driver should be interruptible at all times. The driver, not the system/device, controls the speed of task interaction.

(5) The display shall be easily viewed by the driver and the display shall be easily recognizable.

Experience Design Requirements

(1) For line-of-sight deviation: specify the length of time that a driver’s line of sight deviates from the roadway while performing a task: the average line-of-sight deviation time is no more than 2 seconds; 85% of the line-of-sight deviations are no more than 2 seconds; and the cumulative length of line-of-sight deviation is no more than 12 seconds. Alternatively, visual masking techniques are utilized to derive the need to ensure that the driver completes the task within a series of 1,5-second sight deviations with a cumulative sight deviation of no more than 9 seconds.

(2) For hand deviations:All equipment functions must not be operated by the driver using more than one hand.

(3) For equipment:It is recommended that the active display of each piece of equipment should be as close to the driver’s line of sight as possible.

Equipment Response Requirements

The guidelines recommend that the maximum system response time for in-vehicle electronic devices to system inputs should not exceed 250ms. if the system response time is expected to exceed 2s, a message should be displayed to indicate the system is responding.

Many countries have also made corresponding legislation for driving behavior, and have made clear provisions for making phone calls, browsing electronic devices, sending and receiving text messages and other behaviors during driving. Accordingly, in the intelligent cockpit HMI design, will also make restrictions on the driver’s behavior. For example, when the vehicle speed is greater than 15km/h, the 360° panoramic image is automatically put away.

While driving, the center screen disables video playback, reducing the likelihood that the driver will be distracted by the screen. When there is an incoming call, the steering wheel buttons rather than the center screen to control the connection or hang up. Sending and receiving messages in the car is done through voice interaction with the steering wheel buttons, which avoids the driver typing messages and reduces distraction.

The system also needs to monitor the driver’s physiological and psychological state in real time to ensure their driving safety. When the driver is fatigued, drunk driving, hands off the steering wheel and other dangerous situations, the system should be operated accordingly to remove the danger. The current DMS system in the car can monitor the driver’s fatigue, distraction monitoring, dangerous behavior monitoring, etc. According to the driver’s closed eyes, yawning, vision shift, face angle shift, as well as dangerous actions such as smoking, phone calls, eating and drinking, combined with the driving time, driving speed, and other factors, to determine the driver’s state, and to give the appropriate prompts, such as sound alarms, voice alarms, seat belt tightening, instrument alarm, etc.

Driving safety is crucial in smart cockpit design, it may not be as directly visible as a cool screen, but it is silently protecting the safety of drivers and passengers. When making innovative and eye-catching highlights, smart cockpit HMI should always consider its impact on driving safety and not overpower the main focus.