Choosing the Right LiDAR Sensor: Multi-Echo, Field of View, and Scanning Range

There is considerable development in autonomous driving, robotics, mapping, agriculture, and security. Every industry is encouraging automated task performance with speed and accuracy for higher levels of efficiency. Development in these fields depends on the development of various technologies. One of the most significant of these technologies–critical for advancements in automation and robotics–is sensor tech.

Light Detection and Ranging (LiDAR) sensors have evolved to become indispensable when it comes to enabling machines and systems to perceive their surroundings more accurately. The high-resolution laser-based 2D/3D scanning capabilities of LiDAR sensors allow precise navigation, obstacle avoidance, and environmental analysis.

However, not all LiDAR sensors are built the same. Laser sensors cater to multiple applications, and yours might need a very specific LiDAR solution. Considering the application, you'll have to factor in variables like indoor/outdoor usage, multi-echo capability, the field of view, and scanning range. You may require all these features or just one.

But what context do these features fit into? Read on to find out.

Outdoor or Indoor LiDAR Sensor?

One of the first things to consider when choosing a LiDAR sensor is whether it will be used indoors or outdoors. This consideration holds importance because both environments have different sets of problems, and there might be a specific LiDAR solution that might be more efficient at solving these problems.

For example, outdoor LiDAR sensors are supposed to withstand harsh weather more effectively. Outdoor challenges include strong winds, dust, fog, snow, and even sunlight. On the other hand, indoor sensors need to function efficiently in low-light or dark conditions and bypass interference from other light sources, like lamps, windows, or screens.

Therefore, manufacturers add additional components to these sensors to resist specific kinds of disturbances in sensor readings. These design alterations include water and dustproofing, solid material build, ambient light resistance, interference filtration, and more. Additionally, firmware and software processing play a significant role in parsing signals from noise.

Multi-Echo Capability

The multi-echo feature in LiDAR helps the sensor collect more accurate and reliable sensory data. The LiDAR sensor can detect and measure multiple laser pulses from the same point by leveraging multi-echo laser scanning.

This feature is extra useful in outdoor applications, where laser pulses may encounter transparent or semi-transparent objects like glass, water, or foliage. Therefore, by detecting multiple echoes and sensing objects and transparent obstacles, the sensor provides the required data to make a distinction. Thus, in return, it gets you a more accurate visual reading of the environment or the object.

Also, the multi-echo capability improves LiDAR performance in extreme weather conditions, like snow, fog, or rain. By analyzing each echo's signal strength, timing, and other readings, the sensor can separate the noise from the required information. Additionally, after successful noise filtration, the sensor enhances the signal-to-noise ratio and increases the detection range.

Hokuyo's UXM-30LX-EW has the multi-echo capability and can detect up to three echoes per point. With its muti-echo functionality, it can deliver accurate range scans of up to 30 meters.

Field of View and Scanning Range

Other key factors to consider when choosing a LiDAR sensor are the field of view and scanning range. Field of view means the angular extent of the area that the LiDAR sensor can scan. Furthermore, the scanning range is the maximum distance a LiDAR sensor can take into account.

Both these features matter because they determine the coverage and resolution of the sensor data. Suppose you want a LiDAR sensor for a wide-area surveillance or mapping application. In this scenario, choose a sensor with a large field of view and a long scanning range. Hokuyo's UTM-30LX-EW has a 270° field of view and a 30-meter scanning range that is optimal for mapping and surveillance applications.

But what if you need a sensor for indoor usage, close-range obstacle detection, or collision avoidance applications? In that case, a sensor with a 180° or wider field of view with a shorter scan range can work flawlessly.

Remember, the wider the field of view, the more information the laser sensor can capture in a single scan. Similarly, longer scanning ranges help detect objects at far distances, which is essential for autonomous driving or navigation.

Why Do These Factors Matter?

Choosing a LiDAR sensor is similar to the simple act of selecting a pair of jeans. You can only find a perfect fit if you know what size, style, and material you want. Otherwise, the apparel would cause more trouble than comfort.

Similarly, LiDAR sensors can work optimally when the application is predetermined. If you pick one without a multi-echo feature and deploy it outdoors, it may not generate the accurate 3D mapping you need.

Without multi-echo capability, it can struggle with transparency, foliage, and weather conditions. In the same way, selecting the right scanning range and field of view matters. Mapping a warehouse calls for a wider field of view than navigating down a narrow aisle. You may want to deploy a long-range sensor on a long, straight highway rather than a closed parking space.

These simple, logical considerations can make a world of difference to your robotics, automation, and visual data collection operations.

Hokuyo is one of the pioneers of sensor technology. We would love to know how you apply sensor technologies to your designs or even help you out.

Connect with us to learn more about the LiDAR sensors and their capabilities.