Sensor to detect Human Presence

There are numerous ways to detect people, and they all have benefits and drawbacks. If you explain more about the scenario where you need to detect a person, it would help narrow down the choices. For example capacitance could be used at very low cost, but it has a limited range and could detect other things if they are present. However, if the location is known within a couple of feet and it can only be occupied by a single human at a time, capacitance might work well.

Dear Douglas / others

I am also looking for a sensor to detect both - presence of a person or a vehicle behind a mining equipment like a dump truck or say a wheel loader. The sensor should detect say upto 8 mtrs behind the truck and should cover the entire width of the dump truck which means a horizontal angle of 120 degrees. The operating frequency has to be in free band of 2.4Ghz or 5.85 Ghz. The person or vehicle could be either moving or stationary. There are very few companies which produce such sensors which have to be IP 67 and with good vibration resistance. Does anyone know any source for such product / solutions?....vipul from india

There are 4 main technologies that can meet these requirements - ultrasonic, video, radar, and lidar. You can find many commercial systems based on these technologies, including wireless versions. Search for terms like rear object detection system or parking assist system or vehicle backup system. Most of these systems are designed for vehicle applications and are suitably rugged. If you want to protect them more, simply mount them in waterproof shock-mounts. All of them probably need periodic cleaning if they are expected to work in muddy environments.

There are 4 main technologies that can meet these requirements - ultrasonic, video, radar, and lidar. You can find many commercial systems based on these technologies, including wireless versions. Search for terms like rear object detection system or parking assist system or vehicle backup system. Most of these systems are designed for vehicle applications and are suitably rugged. If you want to protect them more, simply mount them in waterproof shock-mounts. All of them probably need periodic cleaning if they are expected to work in muddy environments.

Many thanks. I did find few manufacturers like eaton , rostro vision eagle eye etc... will get in touch with them, though not sure about their operating frequency.  I would be grateful if you can suggest one or two suppliers similar to preco from mining application point of view.

The frequency should be 2.4 or 5.85 Ghz. Detection distance to be minimum 5 mtrs, preferably 10 mtrs.