Smart sensors stop fabricator going nuts

(See PLUS Automation at FoodManufacturing.Live, 15 May 2025, on stand 49)

Small fasteners like weld nuts and inserts are an everyday part of metal assemblies, but many engineers must surely have wished that a robust mechanism existed for detecting them. Whereas a simple inductive sensor can easily detect a metal part in a plastic assembly or perhaps in a thin piece of sheet steel, inductive sensors get distracted by surrounding metal work, and photoelectric sensors are not easy to use in day-to-day metal assembly production scenarios.

Therefore, inserts, nuts and fasteners have remained a source of frustration for production engineers. Missing fasteners frequently cause scrap parts and potential customer complaints, which can, for example, lead to substantial penalties.

Contrinex's new SMART inductive sensors integrate a microcontroller inside of the sensor to create a tuneable high-performance device. What is equally innovative is the PocketCodr module and companion phone or tablet app, which puts monitoring and configuration of this sensor into the hands of the maintenance or application engineer; if you can use an app like iPlayer, you will be able to create custom sensors using the PocketCodr app.

Using the hand-held PocketCodr module and the companion app on an Apple or Android phone, an engineer can monitor the performance and configure the Contrinex Digital Measurement (DMS) Inductive Smart Sensor, to robustly detect a fastener, configuring a unique sensor for each fastener if required.

PocketCodr, also allows engineers to monitor and configure any brand of IO-Link sensor, not just Contrinex, but perhaps 20+ other sensor brands.

In one application example, the early detection of non-conforming parts and assemblies is essential to minimise manufacturing reject costs and avoid downstream disruption. Anything less than a perfect system introduces the risks of costly downtime, rework, and potentially production scrap or incorrect finished parts. Whilst automated assembly processes are ideal, their high costs often limit their use to high-volume applications that can afford complex detection systems.

If we consider a steel assembly incorporating weld-nut fasteners, this low-value assembly will often lack the volume required to justify automated fault detection. Contrinex's SMART sensors offer affordable, off-the-shelf sensors that can be configured/customised by the metal-assembly manufacturer's engineers to suit their specific assembly job. A sensor could be given several configurations within a multipurpose assembly jig to accommodate different fasteners or variations in the assembly's metal parts. Additionally, the sensor can quickly be reset to enable the sensor or a test jig to be decommissioned and reused on future projects.

Contrinex's high-precision Digital distance-Measurement smart Sensors (DMS) are ideal for this application. The hand-held PocketCodr configurator puts the monitoring and configuration of the sensors into the hands of the engineer on their tablet or phone. The PocketCodr removes the need for any PLC coding or the use of dodgy USB dongles on a laptop, which often do not work consistently across different brands of sensors.

An example assembly check jig to verify correct assembly, could incorporate multiple sensors mounted into quick-change, adjustable fixtures, performing real-time measurements that confirm the presence or absence of individual weld nuts or elements at predetermined positions on the jig.

Sensor robustness is important for the demanding metal assembly environments typically seen by CBM members. Therefore, M12 stainless-steel-bodied embeddable DMS Smart sensors combine compact size and good detection distances while being uniquely robust. The IO-Link-enabled inductive sensors ensure highly accurate no-contact detection, with operating distances up to 4mm.

The ability to quickly select and implement features like built-in delays and timer functions helps ensure that the sensors can stabilise after the assembly is first fitted to the jig, before delivering their output, reducing initial false triggering or false positives.

The modular and adjustable bracketry enables assembly jigs to be easily produced for differing sizes and geometries of assembly. Similarly, using the PocketCodr enables fast, simple configuration of the sensors and requires no coding expertise and no detailed knowledge of IO-Link. The technician or engineer simply connects each sensor to the PocketCodr module and uses the companion app installed on a smartphone or tablet to set and monitor the switching points. As an assembly is presented to the sensor in the jig, the measurement value is displayed with the high/low status of one or more internal switching signals.

The technician assigns the output switching signal (OSS1) to trigger on a user-defined condition, in this instance, when only SSC1 is high. The app intuitively selects every aspect of configuration, and on completion, the sensor is simply reconnected to the machine's control system.

The IO-Link connectivity also provides an easy interface to the PLC control system. After initial calibration, each sensor's configuration is stored automatically on the local IO-Link Master; this allows plug-and-play replacement of sensors should the need arise without any loss of functionality or recalibration.