Cyber-physical systems, or CPS for short, are system units or components that are linked together by means of software, electronics and mechanics, the so-called cyber-physical infrastructure. The technologies from the ‘Internet of Things’ (IoT) and ‘Industry 4.0‘ serve as transmission media. The accompanying exchange of information as well as monitoring and control are handled automatically and above all in the range of milliseconds. The components of such an infrastructure are usually machines, robots, networked individual components (networks (see also Communication in an Information System), computers, chips, sensors and actuators (drive elements), but also conveyor technology, for example within a distribution centre.

Through the pervasion of Industry 4.0 and IoT technologies, product components, machines and other hardware elements can now communicate with each other and exchange the associated information along a production line. This way, the intralogisticsand production sectors, in particular, are being given new tools to adapt the supply chain (see also Value Chain) individually to their needs. Basically, a CPS can consist of individual components, which in themselves also constitute a CPS. As a result, each individual element can connect to form a new system and thus interact with its environment – similar to networked, cognitive production systems.

The basic technologies for CPS can be found in various sub-areas of computer science: embedded systems, event-driven architectures, Internet technologies and sensor networks. Common to all subareas is that they all deal with the control of real-time systems.

Professor Dr. Christian Janiesch, Julius Maximilian University of Würzburg

Cyber-physical systems in practice

With the help of sensors, these systems then process informationand the smallest structured data sets (see Smart Data) from the physical and thus natural world and project them onto the digital level. Network-based services can then use the digitized information and make it available to other machines, robots and components. Actuators or drive elements, including programmable logic controllers, can then participate on the basis of the information and, conversely, directly influence processes in the physical world.

 

Possible components of CPS

  • Sensors
  • Actuators
  • Embedded systems
  • Networks
  • Computer (memory, server, computing power)
  • Computer (memory, server, computing power)
  • Real-time information processing
  • Data bases
  • Dialogue systems
  • Wireless technologies

The IT-publication Computerwoche also lists the following segments

  • Object, services, events
  • Communication
  • Context management
  • Object management
  • Physical/virtual entity
  • Object relations
  • Object memory

The latter enumeration shows that cyber-physical systems do not develop into productive systems from pure information alone. Rather, it is properties and relationships (also situation-dependent) that each individual component assumes or can assume.

A study by the German Federal Ministry of Economics and Energy (status 2018) assumes that augmented reality (AR), virtual reality (VR) or additive manufacturing (AM) will also play an increasingly important role in cyber-physical systems. “In industrial production, Internet-based systems will emerge that will enable remote monitoring of independently operating production systems,” says the Helmholtz Association of German Research Centres, for example. “Initial approaches to CPS are already available today – for example in the form of navigation software. To improve route guidance, it uses mobile phone data to derive traffic jam information from current movement profiles. Other examples are traffic control systems from the fields of train or air traffic. Here the systems actively intervene to control traffic.” Cyber-physical systems are now part of the smart grid and will in future not only guide vehicles through unrecognized areas by means of navigation; CPS will also coordinate road traffic – especially when it comes to automated and autonomous vehicles. In addition, CPS will also penetrate the healthcare system and link patients with doctors and the associated infrastructure (hospitals).

CPS and intralogistics

And especially in intralogistics and production, this routing and the resulting smooth and continuous flow of materials is vital. The challenge here is that today’s distribution centres have to react more and more individually to customer requirements. If, for example, you look at lot size one, an over-proportional growth and the resulting logistical complexity usually hinder each other. Especially the mass production of individualized items via cyber-physical systems is a central challenge for production and transport logistics or intralogistics. In the future, companies will have to react flexibly to customer requirements and offer a large number of product variants in small batch sizes – in other words, the supply chain for each product must develop in a sustainable and collaborative manner. Management tools such as CPFR, ECRand PLMare regarded as supporting factors for this process.

The more complex the systems become, the more logistics must adapt via decentralisation and self-organisation. CPS can already achieve the latter to a very high degree at present. This is also referred to as the *’Design-Driven Manufacturing Process’, in which the design determines the production – and not the other way round (*Source EOS). In relation to batch size one, this means that cyber-physical systems using the aforementioned technologies from Industry 4.0 and IoT enable individual production of batch size one, at the price of a mass product. In addition, such systems in logistics and production offer a demand-oriented optimization of value-added processes; retrofitis one example for this.

Summary of CPS

If one wants to explain the technologies within a cyber-physical system in a practice-oriented way, one usually speaks of intercommunicating products and machines that keep components, goods and information available at the right time and the right place. These are systems with embedded software and electronics that are networked and communicate with the outside world (locally and via Internet) via sensors and actuators. Using sensors, these systems process data from the physical (natural) world and make it available for network-based services that can directly influence events in the physical world through actuators*.

*Source and partial definition of the Helmholtz Association of German Research Centres.

Image: NicoElNino / Thinkstockphotos

If you are interested in topics related to digitisation, you may also want to read the articles Near Field Communication(NFC) and LAN (Local Area Network) / Industrial LAN.

Also available in Deutsch (German)