Advantages and disadvantages of TOF depth cameras and their application areas-Enyo Technology|Customized manufacturer of industrial camera module

Advantages and disadvantages of TOF depth cameras and their application areas

2024-09-05

Technical features of TOF camera

The device that uses TOF technology to imaging is called TOF cameras (or TOF cameras). TOF cameras have similarities to ordinary machine vision imaging processes. They are composed of several units such as light sources, optical components, sensors (TOF chips), control circuits and processing circuits.This technology is basically similar to the principle of 3D laser sensors, except that the 3D laser sensor scans point by point, while the TOF camera obtains the depth information of the entire image at the same time.

TOF technology adopts active light detection method. Unlike general lighting requirements, the purpose of the TOF illumination unit is not illumination, but uses the changes of the incident light signal and the reflected light signal to measure the distance. Therefore, the TOF illumination unit modulates the light at high frequency and then transmits it.

For this reason, the TOF chip pixel size is much larger than the pixel size of the general image sensor pixel, usually about 100um.Both the irradiation unit and the TOF sensor require high-speed signal control to achieve high depth measurement accuracy.For example, a 10 ps shift occurs between the irradiated light and the TOF sensor, which is equivalent to a 1.5mm displacement.The current CPU can reach 3GHz, and the corresponding clock cycle is 300ps, and the corresponding depth resolution is 45mm.The computing unit mainly completes data correction and calculation work, and can obtain distance information by calculating the relative phase shift relationship between incident light and reflected light.

TOFAnalysis of advantages and disadvantages of camera

TOF camera advantages:

1. Compared with two-dimensional images, a richer positional relationship between objects can be obtained through distance information, that is, distinguishing the foreground from the background;

2. Depth information can still complete traditional applications such as segmentation, marking, recognition, and tracking of target images;

3. After further deepening, three-dimensional modeling and other applications can be completed;

4. It can quickly complete the identification and tracking of targets;

5. The cost of main accessories is relatively low, including CCD and ordinary LED, which is beneficial to the popularization of production and use in the future;

6. With the help of CMOS, it can obtain a large amount of data and information, and it is extremely effective in judging the posture of complex objects;

7. No scanning equipment is required to assist in work.

TOF camera disadvantages:

1. Compared with ordinary digital cameras, its cost is still relatively high, affecting the current popularity and use rate of this product;

2. The camera itself is still limited by hardware development, and the update speed is faster;

3. The measurement distance is shorter than that of conventional measuring instruments, generally no more than 10 meters;

4. The measurement result is affected by the properties of the object being measured;

5. The measurement results of most machines are more obvious due to external environment interference, especially when they are disturbed by external light sources;

6. Relatively low resolution,

7. System error and random error have a significant impact on the results and require post-data processing.

TOF cameraApplication field

TOF technology has rich application scenarios and is used in many fields such as automobiles, industry, face recognition, logistics, comfort monitoring, health, gaming, entertainment, movie special effects, 3D printing and robots.

Car:TOF sensor can be used for autonomous driving, and the driving environment is perceived through TOF technology to obtain environmental information to increase safety. In addition, TOF can also be used for passenger off-position detection in the car.

TOF sensor can be used as HMI (Human Machine Interface: Human MachineInterface, in highly automated factories, workers and robots need to work together at very close distances, and TOF devices can be used to control safe distances in various situations.

Face recognition system:The brightness image and depth information of the TOF camera can be connected through the model to quickly and accurately complete face matching and detection.

TOFThe camera quickly obtains the weight of the package (i.e. volume) to optimize the packing and conduct freight evaluation;

Security and monitoring: Use depth of field to count people ( Peoplecounting), commonly known as "counting heads", determine the number of people entering a certain area; through the statistics of the number of people in a flow of people or complex transportation systems, the statistical analysis and design of the security system; and monitoring of detection objects in sensitive areas;

Machine Vision: Industrial Positioning, Industrial Guidance and Volume Estimation; Replacement Equipment for Safety Production Control based on Infrared Light that occupies a lot of space on the station;

Robot: Use deep vision to navigate, identify external environments, plan paths, and implement obstacle avoidance work;

Medical and Biological: Foot orthopedic modeling, Patient activities/Status monitoring, surgical assistance;

Interactive entertainment: motion posture detection, expression recognition, entertainment advertising; when creating film and television specials, the TOF camera can attach depth information to the video image to accurately determine the spatial position of each pixel in the scene.With simple post-processing, special effects props can be inserted anywhere in the video.