Giant proximity sensor

This is a simple sensor (proximity sensor) that functions from 1 to 5,5 meters and can be plugged to an analog interface to transform its response into a protocol such as Midi or OSC (UDP network), such as the « 2/4/8/12 analog inputs to midi » interface boards or our « 16 sensors to OSC » board.

The sensor is available in analog mode (continuous data variation with the distance). It is based on an infrared sensitive module by Sharp GP2Y0A710K0F.

Applications

It can be used as a :

• Presence detector
• Optical barrier for passage detection
• Distance measurement (Telemetry)
• Locating a person in a grid pattern using several sensors in parallel

Since its range is pretty big, it is more used to detect bodies, a whole person approaching, rather than a subtle element such as a moving hand. The hand is a small surface that can easily go out of the sensor's surveillance angle.

The data from this sensor can be processed in many different ways, in order to extract various informations on the behavior of the visitors of an exhibition or the movements of a performer :

• progression direction
• calculation of real distance by linearization,
• calculating speed
• positionning
• counting passage
• memorising a spike of approach
• creating a threshhold to trigger an event...

Examples

Noé Michaud and Mathilde Soliméo, AWAKENING (2016) : 
-> Artwork presentation
-> Project video

Detection when a spectator passes close to an art installation, measuring a hand approaching a precise spot, remotely controlling a sound effect with a lot of finesse, analyzing a footbeat, creating a virtual string, a non-contact musical instrument...

Technical data

Most of the technical data of this sensor is similar to other proximity sensors and is described in greater detail on our general information page. The sensor is very directive, non-linear and its data folds between 0 and 1 meter.

Range

From 80 cm to 5,5 m.

In practice, its true range can go up to 6 meters, but the sensitivity goes quite dull, and it has very little variation on data so close to its range limit. It can be exploited if the data is very clean, denoised, and if the sensor is connected with a shielded extension cord, and placed in a large area with no reflecting surfaces around it.

Please take care to not use the data from the measurement of something closer than 80 cm to the sensor module, for the returned data cannot be exploited the same way. The data returned for distances too short is identical to the data corresponding to distances too far (data folds, the signal is non-bijective). To avoid confusion, it is recommended to not use the data for distances below 1m.

If one needs to use the measurement for very close distances, one should complete the detection with another smaller ranged proximity sensor.

Update rate:

A measurement takes 16,5 ms, so it can do 60 measurements per second, which is sufficient for most artistic applications, not dedicated to measuring only extremely fast movements.

Directivity, paralleling

It is possible to put many side by side but not directly face-to-face. One should move them 40 cm above or aside if one needs them to face each other. The extremely directive measurement cone helps avoid interference between sensors set side by side but one should still try and separate them by at least 40 cm to prevent the reflection of one sensor from bouncing back from an obstacle into a different sensor.

Pros :

• Détecteur sans contact, pour l'interaction à distance.
• Ce capteur est très difficile à parasiter, il est très robuste. En particulier, il supporte les éclairages forts et les variations de luminosité violentes, bien qu'il s'agisse d'un système optique (infra-rouge).
• Il possède une excellente résolution.
• Il est facile à mettre en oeuvre (lorsque l'électronique de contrôle est fournie, comme pour notre version).
• Grâce à l'électronique qui lui est associée, notre capteur envoie un signal débruité et lissé et pleine gamme sur 0-5V.
• Il peut être protégé par une vitre et fonctionne s'il est plaqué contre cette vitre. On peut donc l'utiliser dans une vitrine.

• Contactless sensor for remote interaction.
• This sensor is very resistant to interferences, and very robust. It withstands strong lighting and violent variations in brightness, despite being an optical (infra-red) system.
• It has excellent resolution.
• It is easy to use (when the electronic amplification is supplied with the module, which is the case for our version of the product).
• Thanks to our associated electronic adaptation, the sensor returns a clear and denoised signal that goes full course over 0-5V.
• It can be protected behind behind something see-through, and works even if it stuck against a window. It can hence be used within a glass display case or a shop display.

Dimensions

Electronic card

Module

Can be fastened by the central hole between the two lenses.

Protection

The current version of the sensor can be supplied in a plastic casing to avoid weakening the wires connecting the sensitive module to the amplification board.

Casing dimensions : 88 mm x 57 mm x 39 mm.

Casing options :

Long range, giant proximity sensor.

Giant proximity sensor, in protective casing