24 Jul 2024


Sick claims to have the first full range of ‘smart’ sensors

The German sensor-maker Sick claims that it is the first sensor-maker to offer “smart” sensors across its range, including photoelectric, magnetic and proximity devices. The sensors perform complex functions locally, transferring the processing load from the PLC to the sensor, and helping to optimise the performance of high-speed production lines.

“By building advanced intelligence into standard sensors,” says David Hannaby, Sick’s presence detection product manager in the UK, “Sick has made sensors ‘smart’ and achieved a world first.

“Real-time events can be processed locally, without waiting for the raw data to be uploaded to the central PLC program and processed,” he explains. “Speed restrictions due to heavily-loaded networks are avoided, and demands on the central computing functions are reduced massively.”

Sick has already developed on-sensor functions, including high-speed counters, false tripping suppression, and speed and acceleration monitors. The sensors can share data with PLCs via IO-Link using standard sensor cables. And, because the smart sensors can multitask, traditional sensor tasks can be combined, cutting costs.

One example of a smart sensor function is high-speed counting, which can be used to measure machine speeds. So, for example, an optical sensor can detect and count products on a production line and transfer the results to the control system.

Another example is time-based position measurement which can be used to calculate product lengths, or distances between objects on high-speed conveyors, to ensure they are the right size or in the right position for picking. It can also gauge the dimensions of packages.

A third function suppresses false signals from anomalous triggering events (also known as debouncing) in difficult environments such as sawdust or spray, or where products protrude.

Another possibility is to combine product profile recognition and timing functions to ensure that products are of the right shape or in the correct position for tasks such as picking, sorting or have right packaging.

Time tracking can assign a time value that can locate a product accurately further along the production line, even if there are signal delays in network communications with the central processor.

And precise real-time location provides rapid, local distance sensing to measure product lengths and spacing. As well as improving productivity and quality, the function is useful for monitoring product slippages on moving belts. 

“Smart sensors take the processing load away from central control systems and deliver huge potential in additional flexibility, reliability and throughput for automated production tasks, as well as reducing costs and quality issues,” says Hannaby. He adds that Sick is already extending smart functions to a wider range of sensors, and adding new functions.