Researchers have developed a LiDAR-based augmented reality head-up display for use in vehicles. Tests on a prototype version of the technology suggest that it could improve road safety by “seeing through” objects to alert of potential hazards without distracting the driver.

The technology uses LiDAR data to create ultra-high-definition holographic representations of road objects, which are beamed directly to the driver’s eyes instead of 2D windscreen projections used in most head-up displays.

An image based on LiDAR data (left), converted to a hologram (right).

The holographic images appear in the driver’s field of view according to their actual position, creating an augmented reality. This could be particularly useful where objects such as road signs are hidden by large trees or trucks, for example, allowing the driver to see through visual obstructions. Head-up displays usually project information, such as speed or fuel level, directly onto the windscreen in front of the driver, who must keep their eyes on the road. The new system represents real objects as panoramic 3D projections.

Using LiDAR, the team scanned a busy street using a technique called terrestrial laser scanning. Millions of pulses were sent out from multiple positions along the street. The LiDAR data was then combined with point cloud data, building up a 3D model. The scans were stitched together, building a whole scene that doesn’t just capture trees but cars, trucks, people, signs, and anything else seen on a typical city street. Although the data captured was from a stationary platform, it is similar to the sensors that will be in the next generation of autonomous or semi-autonomous vehicles.

When the 3D model of the street was completed, the researchers then transformed various objects on the street into holographic projections. The LiDAR data, in the form of point clouds, was processed by separation algorithms to identify and extract the target objects. Another algorithm was used to convert the target objects into computer-generated diffraction patterns. These data points were implemented into the optical setup to project 3D holographic objects into the driver’s field of view.

The optical setup is capable of projecting multiple layers of holograms with the help of advanced algorithms. The holographic projection can appear at different sizes and is aligned with the position of the represented real object on the street; for example, a hidden street sign would appear as a holographic projection relative to its actual position behind the obstruction, acting as an alert mechanism.

The researchers hope to refine the system by personalizing the layout of the head-up displays and have created an algorithm capable of projecting several layers of different objects. These layered holograms can be freely arranged in the driver’s vision space; for example, in the first layer, a traffic sign at a further distance can be projected at a smaller size. In the second layer, a warning sign at a closer distance can be displayed at a larger size. This layering technique provides an augmented reality experience and alerts the driver in a natural way. Each individual may have different preferences for their display options; for instance, the driver’s vital health signs could be projected in a desired location of the head-up display.

The researchers are now working to miniaturize the optical components used in the holographic setup so they can fit into a car.

For more information, contact Sarah Collins at This email address is being protected from spambots. You need JavaScript enabled to view it.. Watch a demo on Tech Briefs TV.


Tech Briefs Magazine

This article first appeared in the June, 2021 issue of Tech Briefs Magazine.

Read more articles from this issue here.

Read more articles from the archives here.