Types, structure and principle of operation of the head-up display HUD

The number of systems for increasing safety and driving comfort is constantly increasing. One of the new solutions is a head-up display (Head-Up Display), designed to conveniently display information about the car and the details of the trip in front of the driver's eyes on the windshield. Such devices can be installed both standardly and as additional equipment in any car, even domestic production.

What is a head-up display

Like many other technologies, head-up displays have appeared in automobiles from the aviation industry. The system was used to conveniently display flight information in front of the pilot's eyes. After that, car manufacturers began to master the development, as a result of which the first version of a black and white display appeared in 1988 at General Motors. And 10 years later, devices with a color screen appeared.

Previously, similar technologies were used only in premium cars such as BMW, Mercedes and more expensive brands. But 30 years later from the beginning of the development of the projection system, displays began to be installed in machines of the middle price category.

At the moment, there is such a large selection of devices on the market in terms of functions and capabilities that they can be integrated even into old cars as additional equipment.

An alternative name for the system is HUD or Head-Up Display, which literally translates as “head up display”. The name speaks for itself. The device is necessary in order to make it easier for the driver to control the driving mode and control the vehicle. You no longer need to be distracted by the dashboard to monitor speed and other parameters.

The more expensive a projection system is, the more features it includes. For example, the standard HUD informs the driver about the speed of the vehicle. Additionally, a navigation system is provided to assist in the process of driving. Premium head-up display options let you integrate additional options including night vision, cruise control, lane change assist, road sign tracking and more.

The appearance depends on the type of HUD. The standard systems are built into the front panel behind the visor of the instrument panel. Non-standard devices can also be installed above the dashboard or to the right of it. In this case, the readings should always be in front of the driver's eyes.

Purpose and main indications of the HUD

The main purpose of the Head Up Display is to increase the safety and comfort of movement, due to the fact that the driver no longer needs to look from the road at the dashboard. The main indicators are right before your eyes. This allows you to fully focus on the trip. The number of functions may vary depending on the cost and design of the device. More expensive head-up displays can show driving directions as well as provide warnings with audible signals.

Possible parameters that can be displayed using the HUD include:

• current travel speed;
• mileage from ignition to engine shutdown;
• the number of engine revolutions;
• battery voltage;
• coolant temperature;
• indication of control lamps of malfunction;
• fatigue sensor that signals the need for rest;
• the amount of fuel remaining;
• vehicle route (navigation).

What elements does the system consist of?

A standard Head Up Display consists of the following:

• electronic control unit for the system;
• a projection element for displaying information on the windshield;
• sensor for automatic light control;
• speaker for sound signals;
• cable for connecting to the power supply of the car;
• control panel with buttons for turning on and off sound, regulation and brightness;
• additional connectors for connection to vehicle modules.

Layout and design features may vary based on cost and number of head-up display features. But they all have a similar connection principle, installation diagram and information display principle.

How HUD works

The head-up display is easy to install in your car yourself. To do this, simply connect the device to a cigarette lighter or a standard OBD-II diagnostic port, after which the projector is fixed on a non-slip mat and starts to use.

To ensure high image quality, the windshield must be clean and even, free from chips or scratches. A special sticker is also used to increase visibility.

The essence of the work is to use the protocol of the OBD-II vehicle internal diagnostics system. The OBD interface standard allows for on-board diagnostics and reading information about the current operation of the engine, transmission and other elements of the car. The projection screens are designed to comply with the standard and automatically receive the required data.

Types of projection displays

Depending on the installation method and design features, there are three main types of head-up displays for a car:

• regular;
• projection;
• mobile.

The stock HUD is an additional option that is “purchased” when buying a car. As a rule, the device is installed above the dashboard, while the driver can independently change the position of the projection on the windshield. The number of displayed parameters depends on the technical equipment of the vehicle. Cars of the middle and premium segment signal road signs, speed limits on the roads and even pedestrians. The main disadvantage is the high cost of the system.

Head-up HUD is a popular type of handheld device for displaying parameters on the windshield. Key benefits include the ability to move the projector, ease of do-it-yourself setup and connection, a variety of devices and their affordability.

Projection HUDs are significantly inferior to standard systems in terms of the number of displayed parameters.

Mobile HUD is an easy-to-use and easy-to-configure portable projector. It can be installed in any suitable place and the quality of the parameters display can be adjusted. To receive data, you need to connect the device to your mobile phone using a wireless network or USB cable. All information is transmitted to the windshield from the mobile, so you need to install additional software. The disadvantages are a limited number of indicators and poor image quality.

Projection of vehicle and driving information onto the windshield is not an essential function. But the technical solution greatly simplifies the driving process and allows the driver to concentrate exclusively on the road.