The binocular camera works on the same principle as the human eye, by comparing the same image taken by both lenses at the same moment and comparing the distance difference between the same pixels on different images (the small difference in response at the pixel level between the two lenses due to the apparent distance) to determine the distance, i.e. 3D parallax. This is also a direct type of measurement, and unlike the monocular camera ranging principle, the binocular camera based algorithm produces a more reliable target than the monocular.
As an example, for example, when starting, if the car does not move and the car in front of it does not move, due to the nature of the SfM algorithm requires movement in the picture, then the distance between the car in front and the car at this time is not known by the monocular camera, while the binocular camera can easily solve this problem.
Using the binocular camera, most driver assistance functions other than ACC can be achieved without the need for radar. Another use is to calculate the space available for the vehicle to travel in front of by using the 3D parallax, which we call "free space". Free space is an essential piece of information to be applied in an autonomous driving algorithm.
Of course, with great functionality comes increased costs. Currently, binocular cameras are mostly used in some high-end cars.
While the application of Tesla's Tri-eye camera In the case of the Fisheye camera, three monocular cameras with different detection distances, different fields of view and different functions are combined, including a telephoto camera with a narrow field of view but a long detection distance, a standard focal length camera with a wide field of view but a moderate detection distance, and a fisheye camera with an opening angle of 180° or more for proximal detection. We will not go into details here.
For front-view cameras, whether monocular, binocular or trinocular, their main purpose is to detect objects in the traffic ahead, and depending on the type of target detected, the functions they support are divided into the following categories.
- Based on the detection of vehicles, pedestrians, and cyclists, etc. Safety features such as Forward Collision Warning FCW, Automatic Emergency Braking AEB, etc. can be implemented. That's right! The same function can be achieved with different types of sensors, for example, the AEB function is available in mass production with both radar and camera.