What is a good short range "curtain" sensor? (2 meters)

Help & Support Robot Parts
1

I have unique sensor need, and I can’t decide what the best cheep option is.

What I want to do is create a “digital fence” that would alert when a person departs the sensor range…something like 2 meters. I also want a narrow beam width, think of a curtain as opposed to a cone. Here are the trade offs with the common sensors.

[blockquote]Ultrasonic sensor - NO - sends out a “cone” and collects reflections.
IR sensor - NO/Maybe - same issue as Ultrasonic, but maybe able to filter or focus the output light into a fan/curtain pattern…or perhaps the return sensor could be limited to a ‘fan’ view
LiDAR - YES - this seems like the best way to get the beam width, but now the issue is the price…nothing under $150 it seems like
PIR Sensor - NO/perhaps - I think this is possible, but I want the sensor to only trigger at the absence of motion, when the person departs the area…from my research this sensor only triggers when something is moving in the range…when something enters or departs. Am I missing something?
ToF Sensor - Maybe - I think this is my best bet, I could filter the “vision” to only show the curtain beam width i’m interested in, and then it could trigger by telling me when the time of flight to the closest “person” is outside the fence.
Image sensors - Complex - Would these work for me?[/blockquote]
Picture the laser fence protecting the bank vault in a spy movie, instead of triggering when something breaks the curtain, I want something to trigger when a person waving their arm in the curtain LEAVES the curtain.

2

Hey,

That certainly sounds like a situation where LIDAR-based sensors would do a good job.

Do you know of our latest low-cost sensor, the Benewake TFMINI Micro LIDAR Module IP65 (12 m), also known as the RB-Ben-03. It has a range of up-to 12 m indoors and up-to 6 m outdoors. It also happens to have a IP65 rating!
And the best part is that it is very low cost, so that may be a good option for your use case.

Sincerely,

3

Thanks! I didn’t know about that sensor. I still think I want more of a curtain, and that lidar is more of a beam. I am leaning towards IR with a restriction on the return detector to only allow light from my “slice” to return.

4

You may be interested in the RB-Wav-23 then. It detects interruptions in its beam up-to its maximum range.