Industry 4.0 would not be possible without intelligent sensors

Sensors provide the senses for machines. They provide the feedback that makes intelligent machines possible in the first place. Sensor intelligence focuses on one aspect of sensor technology: equipping machines with the ability to see, recognise and communicate intelligently. Intelligent sensors contribute the ability to classify and interpret information. This is characterised by intelligent signal processing, which derives the truly relevant information from large quantities of data.

This is why – in addition to the primary control system for machines and systems – information is provided for monitoring production systems and making it possible to detect faults. Transparency of processes and material flow produces additional potential for optimisation. Processes are becoming more efficient and cost-effective, increasing competitiveness.

As a driver of technology in Industry 4.0, SICK is already capable of presenting and implementing solutions to the four key challenges throughout the production levels: Quality Control at the sensor-and-drive level; Flexible Automation, at the machine level; Safety at the production level, and Track & Trace, at the corporate level.

Flexible automation: customising goods in the packaging process

Maximum productivity with product variation down to a batch size of one is a central goal of the Industry 4.0 concept. Manufacturing plants have to be flexible and adapt to what the individual customer wants. Due to high product diversity even as the batch sizes continue to decrease, intelligent components (smart sensors) have to be capable of adjusting and controlling themselves.

One example involves the final packaging of prepackaged batches with bottle sizes of 0.5 litres and 1.5 litres capable of being packaged in a system using detection of smart sensors with automatic format changeover. The sensors detect the product changeover and tell the control system that the system has to readjust so the right box can be set up, the bottles can be fed in, and the box can be labelled and shipped.

The changeover steps are listed on a monitor while the machine adjusts. The system keeps running automatically and does not have to be put back into operation manually. If the sensors detect an incorrect placement when measuring the length of the product, they notify the control system. The product is sorted out without the system coming to a stop. Also, the sensors provide data for maintenance, such as monitoring for fine particles to automatically implement measures that safeguard the packaging process.

Smart sensor solutions – using state-of-the-art sensor technologies in combination with complete integration into the control level – focus heavily on decentralising certain automation functions to the sensor. This takes some of the load off of the control system and increases the machines’ productivity.

Safety: Robot protection using laser scanners

Sensor intelligence is a prerequisite for safe interaction between people and machines in the era of Industry 4.0. Safe laser scanners reliably monitor the hazardous area of stationary or mobile machines and systems, such as welding robots or automated guided systems. Protection of people is the top priority. If a person enters the area, the dangerous movement must be stopped safely. On established systems, people are protected, but production is stopped.

In the future, smart sensors will be used not only to ensure the safety of people, but also to implement ever-increasing production specifications. Today SICK is already providing up to four simultaneous protective fields, thereby considerably increasing the ergonomics and efficiency of complex machines such as tire heating presses.

The digitally switching protective fields currently in use are being replaced with flexible ones. Flexible protective fields are automatically calculated during highly dynamic movements and adjusted corresponding to the hazardous areas of the robot. Commissioning is also made considerably simpler and faster thanks to smart sensors.

The optimum interaction of smart sensors and state-of-the-art machine designs increases the productivity of the machine and always guarantees the safety of the employees. The compact systems use an integrated swivel mirror as an optical radar to scan their surroundings in two dimensions and measure distances according to the time-of-flight measurement principle. This results in freely definable safety zones.

Track & trace: production and logistics chains grow together

In an example from the automotive industry, comprehensive data acquisition performed directly at the vehicle makes it possible to identify a customised dream car throughout the production process up until delivery. Using this track & trace process, it becomes clear how increasing product customisation can be implemented in the Industry 4.0 context. Right at the car body, the sensors detect which assembly steps have to be introduced, making mix-ups impossible. As a result, they ensure comprehensive transparency up until delivery.

Processing steps on the object are updated by rewritable RFID tags. Reading reliability is vital because any read errors could cause misdirection, mix-ups or production downtime. This is where RFID data cards – which can be attached to components or even integrated out of sight within them – are coming into play more and more. In practice, they have the highest possible availability. For example, they can withstand high temperatures on a painting line and can be reliably identified even once covered in paint.

Aspects such as transparency and traceability are playing an ever more important role for manufacturers because the variability in the production lines of large automobile plants is constantly increasing and assembly lines are seeing more and more variants built in parallel. Vertical integration is the keyword for track & trace. Traceability of products during complex manufacturing and logistics processes is a priority for this integration. Production and logistics require transparent material flow so that production decisions can be made faster.

Transparency of the material flow based on RFID also plays a critical role in delivery. Until the completed cars are ready to be transported to the dealership, they are kept in a large parking lot. But how do you find the car that still needs to go on the truck? Every single car is made-to-order. No two are alike. Thanks to information stored on a RFID tag, the customer’s dream car can be located and loaded up for transport quickly.

Quality control: reliable data acquisition and tracking

The future holds continued increases in the speed that packages are transported. Distances between the packages are becoming smaller. This means the quality of products is even more important. To accomplish this, the package data is scanned on the conveyor belt and read into the software. The packages are identified and compared. Is the package damaged? Is the code complete? Are the weight and volume the same? Is there a pileup of packages, or could a package even be missing?

Automatic fault detection is made possible by comprehensive product and production data. The data is completely synchronised in seconds. Defects can be tracked by all centres, and it is possible to trace the weak point. Also, quality defects can be identified and resolved in the process. Since the speeds on the conveyor belts are further increased, maximum productivity is ensured – not just within a location, but globally.

This example of an intralogistics process shows how increasing quality requirements and the desire for resource efficiency can be implemented in the context of Industry 4.0. Sensors detect changes to the object and enable seamless data acquisition. The software solution analyses the process data and implements actions. The combination of a variety of data and the analysis software is an important prerequisite for Industry 4.0 and the issue of sustainability. Goods in the production process and supply chain must be reliably, uniquely identified to support efficient automated control. From individual packages on a conveyor belt to a complete overview of millions of packages transported every day, there must be a convenient way to call up and analyse the status of all acquired data.

Smart sensors acquire and communicate this data. However, users do not experience true added value until this data can be used as a basis for improving business processes. This data offers extensive opportunities but also presents the significant challenge of preparing it in a way that allows companies to make the right decisions. This is the cornerstone of Industry 4.0: the seamless flow of data and information from the sensor to the control system and back.

From sensor to sensor intelligence

SICK has always developed and built intelligent sensors. The company’s founder Erwin Sick worked out his vision of sensors with optical and mechanical precision. Starting in the 1950s, he used his vision to create intelligent solutions that had never before existed, such as for safeguarding machines and monitoring emissions. Before long, advances in electronics allowed for miniaturisation of the devices and provided the essential driving force behind technology in automation engineering.

The triumph of microelectronics continues even today. An eloquent example of this is seen in the powerful application-specific integrated circuits (ASICs) that SICK developed and uses in devices such as optical and inductive sensors. The increasing speed in the computing power of state-of-the-art chips enables remote processing of substantially larger amounts of data and capabilities like the associated use of complex mathematical methods. This is resulting in completely new dimensions for the scope, accuracy and ruggedness of measurements. Sensor solutions measuring in multiple dimensions, such as camera systems and laser scanners, would also be impossible without this development due to their high data volume.

Increased computing power enables even more intelligent sensors, but this does not result in sensor intelligence until equipped with the right software and application knowledge. The intelligent linking of application knowledge with the flexibility of state-of-the-art software architectures enables the next development stage for sensors. This is characterised by the possibility of sensors that can perform more extensive analysis, automatically adapt to changes, communicate in the network, and remotely solve complex tasks within a larger manufacturing network. In other words, the sensor links to the machine, the system, the factory and the entire value-creation chain, and provides for transparency in production. As a result, it provides the entry point into the world of Industry 4.0.

For all virtual worlds, however, sensor intelligence remains one thing above all – part of a sensor. Even the cloud and apps need to have a physical basis in the real industrial environment, namely, a rugged and reliable piece of hardware. And building this hardware requires one thing above all: decades of experience.

Christoph Müller is the Manager – Global Marketing & Communication at SICK.

www.sick.com.au