Things you need to know about LiDAR: the more lasers, the better?


When referring to lidar, we often see terms such as "64 channels", "128 channels", and "300 channels equivalent", so what are "channels"? Do more channels form better lidar?

Today, let's learn more about the "channel".

The number of lasers in the vertical direction is called channels for the lidar with 360-degree spinning and 1D rotating mirror structure.

In this case, the number of channels is the number of lasers in the lidar.

Generally speaking, the higher the number of channels, the higher the number of lasers,further improving lidar’s overall performance. It will be easier to understand if we compare the point cloud effect of lidar on different channels:

16 channels/128 channels /64 channels simulated point cloud

Clearly, with more channels, the details of the captured objects are richer, which means the resolution is higher. As shown above, the point cloud image generated by the 128 channels lidar is significantly clearer, and the resolution is much higher than that of the low-channel lidar.

More channels do bring better effects. If 128 laser transmit-receive modules are placed vertically inside a lidar sensor. The sensor becomes very large, causing the cost to increase extremely high, and making it impossible to achieve mass production.

16 channels/128 channels /64 channels laser stacking schematic

Currently, the most cutting-edge lidar technology in the lidar industry has integrated 128 laser transmit-receive modules into the lidar sensors. In doing so, a "genuine 128-channel" lidar can be compact and easily integrated into the car body.

The transformation of 128 laser transmit-receive modules in a discrete architecture

So what are the advantages of a 128-channel lidar? With more channels, you can see clearer.The 128-channel lidar scan pattern is clear, maintaining an overall uniform and high resolution. Whether it is cars, pedestrians, tires, cones, and other details that are easily overlooked, they can be accurately and entirely captured by the lidar, ensuring that the driving system makes the most accurate decisions and avoids dangers.

The more channels, the safer.

Moreover, a higher number of lasers provides greater safety redundancy. Since the 128 lasers work independently, it will not affect the overall perception ability, even if one fails.

To sum up: In the 360-degree spinning and 1D rotating mirror structure, the number of channels is equal to the number of lasers; therefore, the more, the better.

In addition, within the 2D scanning structure, you will learn the concept of "xx channels equivalent". The "equivalent" number of channels uses a small number of lasers to achieve a scanning effect similar to a high number of channels through high-speed 2D scanning. At the same time, there are not so many "channels" inside. However, the industry has not yet defined the "equivalent" number of channels, so we will not discuss this further.

With the development of lidar technology, lidar with higher channels and higher performance will be more compact, and the cost will continue to decrease, becoming the "standard" for more smart cars.

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