by Wiren Perera, ON Semiconductor
The IoT has spawned the concept of the Industrial Internet of Things (IIoT). The IIoT includes the concept of greatly enhanced connectivity in areas such as industrial automation, security and surveillance and building automation. The IIoT uses sensors and actuators embedded in equipment and objects, linked via wired or wireless networks, to improve productivity, and adjust to varying conditions in real-time.
The key evolutionary trends in the IIoT depend highly on innovative enabling technologies and solutions from semiconductor manufacturers. These will help ensure that the transition from the conceptual designs to real-world working implementations happens.
The IoT is here and now and has been for some time -albeit under different names, such as M2M and embedded connectivity. As the consumer-oriented IoT shows burgeoning growth and adoption, the manufacturing and service industries are looking at ways the IoT can be harnessed and exploited to drive productivity into their manufacturing systems. Enter the IIoT—a hugely important and rapidly growing subset of the IoT that is advancing an ever-closer linkage between Operational Technology and Information Technology in businesses. Ultimately, the IIoT will greatly expand the number of ‘things’ that comprise the IoT.
Attributed to Peter Drucker, the phrase “If you can’t measure it, you can’t improve it” is at the heart of the IIoT philosophy. The driving trends are more measurements, a need for rapid and thorough analysis of data, and faster improvements to processes. But, to measure more, we must be able to sense more — more parameters, with more accuracy and more often.
Sensors are fundamental to the IIoT. Overlaying software on existing technologies can bring incremental gains, but for a true step forward we need to bring more parameters into the fold. Every new parameter we sense brings significant opportunity and makes the system smarter. Sensors are the ‘eyes, ears and hands’ that are enabling the expansion of the IIoT and its capabilities.
Traditional sensors continue to evolve; we can measure temperature, light, position, level, humidity, pressure and many other parameters better than ever. But, even as they become smaller, less expensive and more embedded, each of these sensors is dedicated and, therefore, limited in functionality and adaptability. Vision-based sensing removes these limitations; once a machine can truly ‘see,’ almost anything is possible.
With vision sensing, programmability brings flexibility, enabling a single vision system to sense missing or misplaced components or detect a subtle color change that indicates a process is drifting out of control. The IIoT will continue to add more basic sensors to measure the fundamentals, but the trend toward vision-based sensing—both still and video—makes smarter systems more flexible and more valuable.
As production lines and factories are reconfigured to move from one product to another, or to build variants of a complex product, vision systems need no manual repositioning or reconfiguration. They only require a simple change from one control program to the next, and the system is ready to run—lowering costs, saving time and manpower, and eliminating opportunities for the mistakes that humans are prone to making.
In many ways, data is the key to this revolution. Sensors bring data that, through checks, balances and redundancy, we can trust. But post-processing brings the valuable information and ability to control our factories and processes, and to improve them.
One of the biggest challenges and potential stumbling blocks for the IIoT is power. The distributed nature of the IIoT and the need to place sensors where the ‘action’ is makes the reliable delivery of power challenging. And the spiraling energy costs associated with powering this plethora of IIoT sensors can be significant too.
Successful sensors, particularly those intended for the IIoT, have four basic attributes. They need to be self powered, collect data, broadcast their status and have the ability to connect. Energy harvesting (EH) wireless sensors are exactly what is needed to drive the IIoT forward.
Fundamentally, this new breed of sensors needs to be able to measure multiple physical parameters, such as temperature, moisture, pressure and proximity, and communicate the data without the use of a direct power source. For example, ON Semiconductor recently introduced a battery and microcontroller-free, wireless sensor family.
These ultra-thin devices can be used to sense in places where space is constrained or in areas that cannot be accessed by traditional sensors. Similar advances in the acquisition and processing of bio sensor data will fuel the growth of the IoT in the healthcare industry.
It is interesting to explore these new sensors more deeply because they use a single mechanism – antenna detuning – to perform multiple types of sensing. In this regard, they are probably a harbinger of sensing trends to come.
The sensors use RFMicron’s Magnus S2 ICs. They are used to comprise a wireless passive RFID tag composed of an antenna and a Magnus S sensor die. ON Semiconductor’s battery-free wireless sensor tags perform temperature, moisture, pressure, or proximity sensing. The underlying antenna self-tuning technology automatically adjusts the input impedance of the IC to optimally tune the tag every time it is accessed.
Tags based on conventional chips can be detuned by numerous external factors, most commonly by proximity to liquids or metals. Such factors can change the impedance of a tag’s antenna. When the tag chip has a fixed impedance, there’s a mismatch between the chip and the antenna. The self-tuning technology maintains the chip-antenna match as conditions change.
The Magnus S die includes a bank of tuning capacitors between the antenna ports and an RFID engine. The engine dynamically adjusts the chip’s input impedance by switching capacitors in or out of the circuit to maximize the power harvested from the antenna.
Because the tag antenna can respond to a change in environment in a known way, the sensor code can provide a quantized measurement of the change in the environment. This lets the tag become a wireless passive sensor.
Moisture isn’t the only parameter these chips could be used to sense. Solid-state films react to a variety of gases with a change in resistance. So it should be feasible to construct sensor tags that respond to gases such as CO, CO2, NOX, H2S, O2 and Cl2. Thin films deposited on an interdigitated capacitor can produce sufficient change in circuit Q to build wireless passive sensors readable through the sensor code. Proximity at micron resolution is detectable through inductive changes created by eddy currents on nearby metal surfaces. These can be used to detect movement or to build pressure sensors.
However, referring back to the key basic required attributes, the real breakthrough is that these sensors, through energy harvesting, acquire power themselves. The principles are not new and share a lot with large-scale renewable energy initiatives such as wind power or harnessing the tides. Being able to scavenge and accumulate free ambient background energy will allow sensors to work autonomously. The sources are many and varied, and include the obvious solar and wind power but, increasingly, other areas such as kinetic energy, thermal gradients, body temperature and even acoustic noise are being explored.
It’s also important for IIoT platforms to support a broad array of communication standards, including Thread, SIGFOX, EnOcean (used primarily in building automation and security systems), M-BUS (European standard for remote reading of gas or electricity meters), KNX (for building automation), ZigBee and proprietary protocols. The adoption of a software-defined radio approach allows a single platform to support multiple protocols. ZigBee and Thread are complementary, and the alliance of the industry organizations behind these protocols are likely to drive their broad adoption within the smart home.
Thread is an IP-based (IPv6) networking protocol with 6LoWPAN adaptation built on open standards for low-power 802.15.4 mesh networks that can connect hundreds of devices to each other and directly to the cloud. Security and in.teroperability are two of Thread’s key capabilities.
Conversely, SIGFOX enables wide-area networks that provide relatively low bandwidth communication with fixed or mobile smart objects or sensors that are deployed over a large area. Example applications include the nationwide tracking of shipping containers or vehicles and communication with geographically dispersed assets such as oil pumps and pipelines.
For the IIoT to reach its full potential, we have to do something with the information gathered. The feedback loop needs to be completed and binary data needs to translate into physical action. Simple on-off, or ‘bang-bang,’ control is easily realized through the application of semiconductor switches, but many industrial controls are more sophisticated and require proportional control or careful and often rapid positioning. This could mean anything from a fan to control the environment or cool a critical piece of equipment, through to a motor or servo to adjust a valve, or a sophisticated stepper motor to position a robot arm to complete a precision task.
Alongside the rapid development of the IIoT, these actuators and their controllers are seeing similar advancements. The discrete solutions to motor control are fast disappearing and new, advanced integrated power modules are taking their place. Offering complete systems—including power stages, drivers, protection and control logic in a single module—these new, highly integrated solutions are lighter, smaller, cheaper and easier to implement.
The breadth of sensing technologies needed for an integrated manufacturing process brings its own challenges. The wide-ranging expertise needed to build a smart factory full of sensors and actuators is beyond the breadth of many engineers, and this is where we see leading component suppliers providing value.
Fully integrated hardware and software development environments are crucial to facilitating the customization of specific functions for adoption into end products. Modularity makes these platforms extensible to new IoT/IIoT functions and devices that are based on new embedded solutions, allowing rapid adoption. Open-source support is also important, since a broad ecosystem and interoperability are crucial for the IoT’s success.
Take the all-important vision capability as an example. From a hardware perspective, this requires video processing skills to implement; not to mention the image-processing software to do something useful with the data stream. To accelerate design cycles in this area, ON Semiconductor is sharing its knowledge with customer engineers through tools such as the MatrixCamTM video development kit (VDK). Similarly, the recently introduced IoT Development Kit for EH wireless sensors allows the movement of sensor data to the cloud for applications development. These are a few of the many examples where companies are sharing their specialist knowledge through development kits or reference designs, which is contributing significantly to the rapid growth of the IIoT.
The true autonomy of factories and manufacturing processes is getting ever nearer. The ability to remotely identify, monitor and control every individual device on a network offers unparalleled opportunities—especially in industrial applications. Critical to the IIoT’s success is the effective meshing and connection of sensing, computing and control technologies in a resilient and energy-efficient manner.
The rapid development and innovation occurring in the IIoT arena is driving clear business benefits, in terms of management efficiency, reduced operating costs and more resilient, self-learning, processes. Leading semiconductor companies are at the forefront in enabling this IIoT future, with their wide breadth of capabilities and technologies.
It won’t be long before smart factories are sending messages to mobile devices the world over saying ‘There was a problem, it’s fixed and everything is back on schedule.’ Welcome to the brave new world of the Industrial Internet of Things!