Smart Optical Sensors Put Industry 4.0 to Work | Automation.com

Smart Optical Sensors Put Industry 4.0 to Work

Smart Optical Sensors Put Industry 4.0 to Work

By Sergey Komarov, Field Applications Engineer, TT Electronics

Smart manufacturing. Factory automation. Industry 4.0. No matter what you call it, the ‘fourth industrial revolution’ is here. Powered by the Industrial Internet of Things (IIoT), connected devices and smart equipment are streamlining manufacturing and supply chain processes large and small, on a global scale. Smart sensors are integral to this sea change, extending the legacy sensor’s inherent abilities―to collect, store and monitor data―to new levels that capitalize on data in context to optimize processes.

This optimization of processes is not without its challenges though. Manufacturing and assembly machinery can be dirty and may need to run in fluctuating and extreme temperature conditions. Ambient lighting can vary widely with dark and bright periods, including full daylight. Packaging, printing, and labelling equipment require robust presence detection from various media with low-contrast reflectivity. Logistics require reliable presence detection for accurate routing. And engineers need smaller and simpler circuit designs with flexibility.

Sensors and connectivity are key elements to meeting these challenges, enabling efficient manufacturing via the IIoT. The key here is to employ ‘smart’ optical sensors that consider the bigger picture.

For example, manufacturing equipment maintenance generally has been performed on a somewhat arbitrary or ‘recommended’ schedule rather than ‘when needed.’ Worse, repairs are usually made when a part stops functioning properly or breaks altogether, likely disrupting production schedules. With smart sensors, these issues are completely avoidable via contextual data that identifies situations to be averted.

In these circumstances, the optical sensor is ideal. It is extremely versatile in its ability to look at objects (such as products on a manufacturing line), through media (such as liquids flowing through tubes), or at reflections off things (such as surfaces that have been processed in some way). However, acquiring the kind of accurate, repeatable measurements that make analysis meaningful can be difficult. For example, as anyone who has fitted a screen protector to their phone can confirm, an increasing number of materials with low reflectance has become available. Making sense of the resulting signals calls for a sensor with programmable sensitivity levels and output to manage the varying levels of reflectance and low contrast settings.

Sensor signals are often quite ‘delicate,’ that is they tend to be small currents or voltages measured in electrically noisy conditions from sensing devices that change performance with environmental factors such as ambient light or temperature, and over their operational lifetime. LED performance inside the sensor is subject to ageing as light output in LEDs degrade gradually over time. An adaptable sensor merely recognises and re-calibrates to this change. Its readings remain consistent from day one to years through the life of its deployment, critical in complex manufacturing settings where the expense and downtime from a sensor failure can shut down operations.

 

Optical Sensors Power the Factory Floor

On the manufacturing floor, connected devices are essentially creating networks of highly instrumented devices, the impact of which remains to be seen. We do know, however, that much of their utility relies on implementing one or more sensors to recognise changes in diverse, real world environments and turn them into electrical signals that are measurable and actionable. Industrial settings require accurate readings – facilitated by sensors that are highly integrated, small, robust, stable over the long term, and draw little power. This unique combination of features and performance is critical in keeping industry running smoothly and safely with minimal downtime for maximum factory productivity.

Industrial sewing provides an excellent example of sensors in action, powering systems that are far more sophisticated than the pedal-controlled, mechanical versions familiar to us as consumers. Electrical rather than mechanical, advanced sewing systems may operate non-stop on the factory floor – handling different stitches on a variety of fabrics with diverse textures and general characteristics. As with any type of electrical system, safety must be engineered into the product. In this scenario, sensors are tasked with detecting the presence of fabric and activating the machine only when fabric is centred over the throat plate of the device. This action not only permits the needle to pierce the fabric at the appropriate speed and depth, but also reduces thread waste by powering on only when the fabric is correctly positioned.

Adaptable sensors are programmed to recognise different types of fabric, for example adjusting the machine’s speed and intensity to accommodate lightweight or more transparent fabrics. Factory floors can also experience temperature extremes, with big sways between heat and cold; adaptable sensors are responsive, automatically re-calibrating and adjusting their output based on the status of their environment. This also applies to ambient or shifting light conditions common in industrial settings. An optimised adaptable sensor can screen and filter out the ambient light from its environment and continue to perform flawlessly by detecting the light coming only from its own LED.

An example of such a device is the TT Electronics Photologic V OPB9000 reflective optical sensor, expressly designed for industrial applications. This optical sensor comprises a fully integrated analog front end, on chip processing and digital interface in a surface mount package measuring 4.0mm by 2.2mm by 1.Integration solves many factory challenges, transforming a standalone sensor into a low-power sensing module that contains all its supporting circuitry and has programmable sensitivity and thresholds.

 

Industry 4.0 Thrives on Flexible Technology

Smart factories require smart technology. In our industrial sewing example, sensors manage factors that keep machines running safely and at optimal performance. Thread tension, needle force, even measurements such as thread usage are all features that can be managed with smart, integrated sensors.

These tiny devices fuel the connected factory floor, allowing manufacturers to tap into real-time performance data that allows continuous improvement in a highly competitive manufacturing landscape.  And because industrial settings are so diverse – performance critical and potentially dangerous to human workers – smart sensors also deliver value while reducing risk. 

Optical devices are ideal in these settings, measuring and sensing a range of conditions, and consuming minimal power. These highly integrated devices are small, and able to withstand a tough environment – all key characteristics that improve equipment portability or, in the case of manufacturing applications, a greater ability to be used in more challenging factory environments.

About the Author

 

Sergey Komarov is a Field Applications Engineer specializing in opto-electronics in sensors applications. Sergey has over 20 years of industry experience in technology development and product engineering at TT Electronics, AB Elektronik GmbH, Optek, Cadence Design Systems, Texas Instruments and National Semiconductor. He holds degrees in Physics, Materials Engineering, and an MBA in Industrial Management. His passion is to research and pursue new opportunities in opto-electronics sensing technologies, innovative designs and applications. Contact Sergey at [email protected]

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