The term cyber-physical system was coined in 2006 by the United States National Science Foundation’s then Program Manager Dr Helen Gill1. However, these systems have a much longer history that dates back to the beginning of cybernetics, which was defined by mathematician Norbert Wiener as the science of control and communication in machines and humans2.
“Cyber-physical systems (CPS) combine, and build on, elements from different scientific theories and engineering disciplines, including cybernetics, embedded systems, distributed control, sensor networks, control theory and systems engineering,” says RMIT’s Cyber-Physical Systems Research Group Leader Professor Roberto Sabatini.
“These theories and disciplines support the optimal integration of digital and physical components, which maximises the synergies between the two and allows achieving significant benefits both in terms of cost, performance and overall life-cycle sustainability.”
Roberto says that many definitions have been introduced in the recent scientific and technical literature. In general, a commonly accepted definition of cyber-physical systems refers to systems where software and hardware components are seamlessly integrated towards performing well defined tasks. Increasingly, these tasks are highly automated and distributed amongst multiple agents, while recent research trends support the introduction of artificial intelligence (AI) and machine learning functionalities. This is helping us move towards building trusted autonomy in what we call ‘intelligent’ cyber-physical systems or iCPS.
“This requires three fundamental attributes to be present, also known as the three Cs – communication, control and computing. Unless these three elements are present you will not have a system where physical processes can affect computations and vice versa.”
Cyber-physical systems generally combine sensor networks with embedded computing to monitor and control the physical environment, with feedback loops that allows this external stimulus to self-activate either communication, control or computing3.
According to Roberto, there are two categories of cyber-physical systems, autonomous cyber-physical systems and closed-loop human machine systems.
Autonomous cyber-physical systems are systems that are capable of making decisions and operating independently. However, at this point in time, cyber-physical system development is mostly in semi-autonomous systems. These are systems that operate independently only in pre-defined conditions, such as semi-autonomous drones. Users can set a flight path and then real-time machine vision will enable the drone to avoid obstacles, removing the need for manual flying,” says Roberto.
“The other type of cyber-physical systems are closed-loop human machine systems, or cyber-physical-human systems. In these systems, a human operator is able to interact with the other elements of the system only if and when needed. The system is a cognitive system, able to learn from the environment, from the human and from itself to make decisions in real-time, but the human remains an integral part of the system’s decision-making process.”
Around the world, governments and labs are investing huge amounts of money into developing this technology further but the uptake by industry in Australia has been relatively slow.
“It does depend on industry though,” says Roberto.
“In the aerospace industry for example, there is quite a high degree of cyber-physical system use but in other sectors cyber-physical systems are radically different to what they normally use, which impacts the rapid uptake of this technology. In these instances, businesses need to hire specialists with the skills to implement, manage and use cyber-physical systems, which can have a significant cost in the short-term, while the long-term economic and technical benefits might be hidden and not immediately quantifiable by non-experts.”
However, it is now absolutely clear within the research community that the potential benefits are huge even for industries where the term cyber-physical systems might not be widespread.
In healthcare, for instance, cyber-physical systems can be used to remotely monitor the real-time physical conditions of patients using non-intrusive wearables to limit hospitalisations4. These systems can also be used to help more people ‘age in place’, using sensors in homes to detect falls or illness and automatically raise an alarm5.