About LiDAR's rain countermeasures
About the influence of rain on LiDAR
Separation of objects and rain by multi-echo
Hokuyo LiDAR is equipped with a multi-echo function.
When a laser hits a transparent or translucent object such as glass, rain, or fog, two types of laser may return to the sensor: the laser that is reflected by the transparent object, and the laser that is transmitted by the transparent object and reflected by the object behind it. .
The multi-echo is a function that can acquire distance data only from multiple laser beams returned at the same step angle.
By using this function, it is possible to distinguish rain or fog and the objects that actually want to detect with the returned distance value from the sensor.
Also, in case of the sensor type that sets an area for obstacle detection, data processing is generally difficult, so the echo selection is used by selecting the last echo.
As a point to note, rain is easy to get measurement data at a short distance, but the echo separation characteristics depend on the object and the environment, so separation will not work unless the distance difference between the measured rain and the object is 3m or more.
It may not be possible to measure small objects at short distances.
Rain filter with LiDAR
Minimum object setting
Needless to say, this means that smaller objects cannot be detected.
Recommended LiDAR
・LiDAR outputs data with a range 30m and 270°and detects obstacles by area setting
- Scanning Rangefinder
- Photoelectric Switch
- Sensor for Iron & Steel Industry
- Optical Data Transmission Device