# A sensor that can see glass/transparent objects and surfaces

I am currently thinking about making a robot that will autonomously drive around the place. The place I want this robot to drive in however contains quite a few glass walls. When mapping the area I would need to be able to see the glass. For this reason I am in need of a sensor that can see the glass, and not see through it. What kind of sensor would be the best for me? I need it to have a maximum range of about 2-10 meters and a minimum range of about 0.25 meters (preferably as small as possible). I was thinking about maybe using ultrasonic, but I was told that a laser-based sensor would probably be best. I could however only find industrial grade laser sensors that could see glass/transparent objects.

• Thermal sensors, while expensive see glass as an opaque surface. You might get similar results using infrared lamps and detectors. – Octopus Mar 8 '17 at 6:34
• @Octopus considering it will be on a moving robot in a regular environment, I doubt that using infrared lamps and detectors would work. Having to put up detectors all over the place is kind of out of the question. I will however have a look at thermal sensors. Thanks for the input! – John Bow Mar 8 '17 at 12:15
• @Octopus I can't seem to find any information on Thermal Sensors that can tell me how far away the glass would be. I might have missed mentioning this in the post, but to avoid collisions with the glass, I ofcourse need to know the distance between the robot and the glass. – John Bow Mar 8 '17 at 12:31
• Sorry, I didn't mean to imply that a thermal sensor can be used to measure range, it would be too complex and expensive anyhow, but that since thermal sensors see glass as opaque, then I imagine a basic IR proximity sensor probably would, too. – Octopus Mar 8 '17 at 17:56

• Sure, the biggest one that comes to mind is the Lidar Lite V3 but it cannot detect surfaces that are reflective or clear, same for all LIDAR units that I know of in the lower than $1200 range. For the 0-10m range I think that Ultrasonic sensors are best, and for less than that IR proximity sensors will work well. – Mark Omo Mar 8 '17 at 20:48 Do you maybe have some examples of laser-based sensors too? I will recommend this Mini Lidar sensor that only costs$39.9