24 Jul 2024


LED-based position sensing technology ‘is a better buy’

A Canadian company called LeddarTech has developed an LED-based presence detection and ranging technology for industrial applications which, it claims, offers a better cost/performance ratio than existing technologies such as lasers, radar, thermal imaging, ultrasonics and passive infrared.

The Leddar technology, which operates over distances of up to 50m, can provide both the distance and angular position of targets. It can detect, locate and measure solid or liquid objects in harsh conditions. It contains no moving parts and comes in a rugged, weather-resistant IP67 enclosure.

The time-of-flight technology uses pulses emitted from a series of independent infrared LEDs – typically 16 – that are combined in one sensor that produces a 45-degree wide beam split into 16 segments. It analyses how objects in the path of the beams backscatter (reflect) the beams to provide rapid, accurate and continuous detection and ranging, without needing any moving parts.

The light pulses are processed using innovative algorithms and the technology is said to operate with an accuracy of 5cm and a resolution of 2cm.

The sensor (above) can be configured at the touch of a button. A presence detection mode allows the outputs to be set according to whether or not there are objects within configured detection zones. A “teach configuration” mode uses the perimeter of the sensor’s surroundings as the detection zone. Measurements from all of the segments can also be acquired in real time via an RS-485 link. 

Until now, the Leddar technology has been used mainly in specialised applications such as traffic control and vehicle management. The new industrial version is designed to be integrated easily into a variety of applications.

In one application, the technology is being used to gauge the quantity of a bulk raw material being carried on a conveyor belt, and using this information to control how much additive is mixed in at a later stage in the process. Previously, the manufacturer had to rely on chemical analyses of samples of the material taken at the end of process.

In this application, the Leddar sensor is installed above the conveyor, pointing down. The readings from the 16 LED beams indicate how the height of the bulk material varies across the width of the conveyor and this information is combined with the conveyor speed to calculate the volume of material passing along the conveyor. This data is then used to control dynamically the quantity of additives poured into the mix at the next stage in the process.  

Sonia Bélanger, LeddarTech’s vice-president of sales and marketing at LeddarTech, points out that the Leddar technology available in different formats, such as assemblies or modules, “so depending on the final application, it can be easily integrated into customers’ own applications and can serve several industries.”