Application of SMB coaxial connector for automotive cameras

Application of SMB coaxial connector for automotive cameras

Nowadays, driving smart connected cars and using smartphones have a similar effect, with the ability to connect to the internet and familiar mobile applications, and the "supercomputer" behind it acting as the "brain" of the car. Differently, cars have "kinetic energy" and need to interact with people, cars, and roads, therefore, perception systems play an important role in smart cars.

The car perception system consists of cameras, millimeter wave radar, laser radar, etc. Among them, cameras have the longest application history in car perception. Due to their low cost and mature technology, they complement the advantages of sensors such as millimeter wave radar, and their position will be difficult to replace in the long run. At the same time, in order to comply with the trend of intelligent and networked automobiles, the threshold of the car camera and car imaging industry is gradually being raised, including higher image quality, more complex hardware configuration, and higher computing power requirements.

More cameras and applications on the car have become an important symbol that distinguishes intelligent cars from traditional cars, and also an important manifestation of automotive technology innovation. Let's take a look at some applications of car cameras.

1.Forward view: ADAS function and larger field of view

The cameras used for sensing the external environment of the vehicle are generally distributed in the front, rear, and sides of the vehicle, with an external quantity ranging from 4-8. The main purpose is to detect the surrounding environment of the vehicle, provide the driver with information about the surrounding environment, and to some extent achieve auxiliary driving functions, including adaptive cruise control, lane departure warning, pedestrian vehicle collision warning, etc. Forward facing cameras are generally installed behind the windshield, with a installation quantity of 1-3. The configuration can meet a wider field of view, deeper perception ability, and high dynamic range.

Taking Tesla as an example, there is a combination of three front facing cameras, namely a front wide field of view (fisheye lens with a field of view of 120 °), a main field of view, and a narrow field of view camera. NIO's new model ET7 adopts different installation methods, with three cameras in the front, one located behind the windshield inside the car and the other two installed on both sides of the roof outside the car, in order to improve the viewing angle, avoid adjacent vehicles blocking pedestrians and obstacles, and enhance driving safety.

2. 360 ° panoramic view system+chassis perspective imaging system: escorting safe autonomous parking

A 360 ° panoramic surround view system generally consists of 4-6 high dynamic range and high-resolution cameras, distributed in front of, behind, and on both sides of the vehicle. The system forms a bird's-eye view of the image information collected by the cameras around the car body, and projects it onto the car center console, with a panoramic view covering the surrounding area of the car body.

Under the trend of intelligent automobiles, the 360 ° panoramic view system has also become an important technological foundation for autonomous parking and one click vehicle start functions, usually requiring the use of millimeter wave radar to achieve more accurate road and obstacle detection.

In addition to the 360 ° panoramic view system, some car manufacturers have also proposed upgraded "chassis perspective" imaging systems to achieve higher safety factors in parking. The principle is to project real-time image information of the front and bottom of the vehicle onto the central touch screen, presenting a clear 180 ° virtual view. At present, chassis perspective imaging systems are mostly applied to SUV models, and other levels of models are gradually following suit.

The combination of 360 ° panoramic view system and 180 ° chassis perspective imaging system further eliminates blind spots and avoids risks for autonomous parking function. For example, the Lynk&Co 06 released in early 2021 is equipped with a 540 ° panoramic intelligent imaging system, which adds a 180 ° chassis perspective imaging system to the 360 ° panoramic surround view system.

Intelligent cockpit

1. DMS (Driver Monitoring System): From commercial vehicles to passenger cars, the trend of growth is unstoppable

DMS is currently the fastest-growing application field for in cabin cameras in recent years. With the promotion of policies such as "two passengers, one danger", DMS has gradually become a standard for commercial vehicles and will also penetrate into passenger cars. Not limited to ride hailing services, DMS functionality will play an important role in safe driving until L4 and above autonomous driving technologies truly arrive. Based on computer vision technology, DMS cameras capture facial parameters of the driver and compare them with a preset database to determine whether the driver is distracted or fatigued, thereby triggering the warning system to refocus the driver's attention.

The installation position of DMS cameras is generally located on the ceiling or A-pillar directly above the driver. In addition, some manufacturers have innovatively hidden cameras between the steering wheel and dashboard, which is both aesthetically pleasing and space saving to a certain extent. For example, the Cadillac super cruise shown in the picture below:

Previously, the DMS camera inside Tesla's cockpit sparked controversy over privacy breaches. Inspired by Mark Zuckerberg's use of sealant on laptop cameras back then, the automotive electronics industry has also started the business of camera cover accessories. Such as the BYD Han and the recently released Serys Wenjie M5.

In addition, DMS cameras can not only serve as sensors for monitoring the driver's status, but can also be combined with AR HUD products, transparent A-pillars, and other applications that require calculating the driver's line of sight.

2. OMS (Occupant Monitoring System): It has a place in protecting personal and property safety

OMS (Occupant Monitoring System) is a derivative application of DMS function that extends to the overall interior space of the car. Similarly, OMS is based on visual technology to detect passenger seats, rear passengers, and debris, including seat belt detection, passenger posture detection, and passenger quantity detection, especially for detecting and reminding of vehicle owners' debris and children after getting off the car, playing a role in personal and property safety.

Whether it is DMS or OMS, their current applications mainly remain in the early warning stage, and both have greater room for expansion and imagination. They can be combined with AD/ADAS systems to achieve personalized vehicle control functions. For example, by combining algorithms and machine learning, identity authentication and richer human vehicle interaction can be achieved through facial recognition and emotion recognition. When the driver's identity is recognized, seat adjustments, personalized playlists/radio recommendations, and commonly used navigation destination recommendations will be provided based on the corresponding individual's preferences or habits.

3. In car gesture recognition and control: an emerging way of human vehicle interaction, with early large-scale applications

In the past, gesture recognition and control, as a "black technology", caused a stir due to the application of BMW.

The 3D camera on the center console is the perception hardware foundation for gesture recognition and control inside the car. It analyzes gestures based on the time difference between the emitted light and the receiver (hand), and compares them with the preset gestures in the system to achieve corresponding operations. Gesture control, as an emerging human-computer interaction method, can replace some touch and tap operations. At present, in car gesture recognition interaction is still in the early stages of development, mostly used for streaming media control. It cannot replace physical buttons and touch controls in safety device control, central control screen, etc.