dToF 3D Lidar : Working, Benefits & Vendors

Introduction : In the fast evolving world of autonomous systems, direct Time of Flight (dToF) 3D LiDAR has emerged as a game changing technology. Unlike traditional LiDAR solutions, dToF LiDAR directly measures the time it takes for a laser pulse to travel to an object and back, enabling highly accurate 3D depth perception in real time. This makes it a critical component in autonomous vehicles, robotics, drones, industrial automation and smart city applications. In this application note, we will explore how dToF LiDAR works, its key advantages over other depth sensing technologies and highlight the leading vendors shaping the LiDAR market.

How dToF 3D Lidar works?

The normal LiDAR captures distance in one or more horizontal or vertical slices e.g. 2D LiDAR. This is used in robotics for obstacle detection, mapping floor plans or as range finders.

The term dToF refers to direct Time of Flight and 3D liDAR refers to three dimensional Light Detection and Ranging. The 3D LiDAR captures full three dimensional information (X,Y,Z) over a volume or field of view, not just along one plane. Let us understand its working.

• A laser emits very short pulses towards the scene. The light gets reflected off the objects in the scene and returns the reflected signal to the Sensor of LiDAR.
• The system measures time between emission and when the pulse returns.
• As the speed of light is known, we can calculate distance using following Formula.

• By scanning over many parts of the scene, dToF LiDAR generates 3D depth map showing how far each point in the scene is.

Image Courtesy : Orbbec Technology

The figure depicts internal view of 3D LiDAR (model : Pulser ME450) developed by Orbbec Technology. As per datasheet available on company website, it has following typical specifications.

• Measurement Range : 0.145.0 m @ 90% ; 0.115.0 m @ 10%
• Accuracy : +/-30 mm
• Precision : +/- 20 mm
• Horizontal FoV : 270 degree
• Vertical FoV : 60 degree, can be set as 45 degree / 30 degree

Advantages of 3D Lidar

Following are some of the benefits of direct time of flight 3D liDAR technology.

1. It offers millimeter (mm) level accuracy and maintain precise measurements over long range.
2. It enhances durability and reliability due to reduced moving parts in its design compared to traditional liDAR systems.
3. The dToF modules are more compact and flat which enables integration into space constained systems.
4. dToF based LiDar systems are less susceptible to ambient light interference. Hence it offers stable performance in various light conditions.
5. It supports high speed data acquisition which facilitates real time processing and applications such as robots, gesture recognition etc.

3D Lidar Vendors

Conclusion: By delivering long range detection, superior accuracy and reliable performance even in challenging lighting conditions, dToF 3D LiDAR is quickly becoming the preferred choice for manufacturers and innovators worldwide.