Sensors 4.0: The Road Ahead

A German study paints a very exciting vision of smart sensing with Industrie 4.0 already here or slated to come in the next few years to make better plants easy. The roadmap describes composite measuring systems with sensors talking among themselves, valve positioner talking to sensors, new multi-measurement transmitters, 3D profiles for more measurements, mutual plausibility checks, sensor firmware update, new business models, and more. Is this farfetched or can plants already achieve this? Here are my personal thoughts:

The VDI/VDE 2015 process sensor 4.0 roadmap at 40 pages is long but interesting. It is in German, but with two years of high school classes and Google Translate I managed to battle my way through it. I wish it was available in English. It matches my own thinking very closely.

https://www.namur.net/fileadmin/media_www/Roadmap_Dateien/Roadmap_Prozesssensoren_4.0.pdf

One word really stands out in the roadmap: “network”. Digital communication is the focus of the 2015 edition of the sensor roadmap. It reminds us the future is digital, also for process automation.

Using more Information and Communications Technology (ICT) in automation is important. That is, digital networking and software analytics. This offers a great opportunity for optimization of process management because plats can have more sensors with less wiring, and software can distill raw data into actionable information. That is, less manual data collection and operators need not watch or try to make sense of all the numbers; the analytics software helps. It is not just about individual sensors, but increasingly about “measuring systems” for composite information generated from the sum of multiple individual sensors. For instance, a two-wire intrinsically safe tank gauging system is an excellent example of a measuring system that already exists; a system of sensors stringed together using Foundation fieldbus to compute storage tank inventory. The same could be done in the future for two-wire intrinsically safe custody transfer flow metering systems and two-wire intrinsically safe condition monitoring systems etc.

There are transmitters which cannot be done using 4-20 mA but which are already available with digital communication; such as 8-input Foundation Fieldbus temperature transmitter or 4-input WirelessHART temperature transmitter ideal for capturing temperature profiles. That is, digitally networked sensors can measure several variables. They are not limited to a single measurement per device. Therefore, multi-input temperature transmitters can be used in place of 4-8 regular 4-20 mA transmitters.

Digitally networked sensors are a prerequisite for the realization of “Cyber Physical Systems”, Industry 4.0, and Internet of Things.

Simplicity and intuitive operation is critical. It is paramount that using sophisticated sensors is easy. If not, they will not be fully utilized. The user interface for the first generation of Fieldbus devices was in hindsight not as good as it should have been. We though showing hundreds of variables was a feature... Today we know better. EDDL “dashboards” dramatically simplify the user interface for digital devices. WirelessHART and Foundation fieldbus transmitters now have a user interface just as user friendly as for a simple 4-20 mA transmitter. In the past, using digital communication networks like Foundation Fieldbus was not as easy as it should have been. However, lots have been done for the technology and product implementation with the result that it is now easy to use. For instance it is possible for an instrument technician to replace a fieldbus device using only a screwdriver, without touching control system software.

Advanced wireless sensors for acoustics noise, vibration, and corrosion are already available

In the future, level transmitters and flow meters will all also measure process pressure and temperature in the same device, eliminating the need for separate transmitters and process penetrations for each one. All the measurements will be communicated over the same pair of wires. With the increased number of measurements mutual plausibility checks between sensors becomes possible to uncover inconsistencies in sensor readings which would previously have gone undetected.

Today some transmitters have USB port for local connection of a laptop computer without the need for RS485 or other interface converters. Some devices have the USB port where a USB drive can be plugged in, enabling transfer of configuration settings, device logs, or other device data. Devices could even be configured from smart phones and tablets provided the "apps" are provided. However, note that USB is short distance for local connection in the field. USB is not for long distance. Industrial networking is still required for the long connection to the control system and Intelligent Device Management (IDM) software.

Instrument networks are more dynamic and versatile as sensors can easily be added ad hoc and unused additional real-time measurements signals in a device can be turned on at a click of a button without adding wires or system input cards. Examples of this includes density and volumetric flow in a mass flow transmitter, interface level in a guided wave radar level transmitter, or flow direction in a magnetic flow meter etc.

In the past, digital communication was only used for measurements requiring very high accuracy such as for inventory tank gauging systems where 4-20 mA is not accurate enough, or for measurements with lots of measurement values such as a gas chromatograph where wiring all the signals with 4-20 mA would be too expensive. However, with wireless and Fieldbus all transmitters can be digital to enjoy their full accuracy and all the measurements they can provide.

ICT in addition to reducing installation cost and maintaining high accuracy is also key to attract the young generation of engineers. The new hires now coming into the industry is the young ICT generation. Automation systems must be ready for this young generation. Moreover, ICT solutions are required to enable a smaller number of engineers to cope with the same work or more as many retiring engineers. The young generation grew up with computers, software, the Internet, smart phones, tablets, and apps. They find these self-evident. Automation systems need to be digital too creating a modern working environment for young engineers for the process industries to attract the appropriate specialists and executives.

The roadmap brings up another point that has been on my mind for many years; when we work and create with most software we make changes and delete them, doing and undoing, to see how it turns out. This way of working and thinking might be possible in automation too, within reason of course. Automation systems may be able allow for this with networked sensors. Will we see more “Undo” buttons in automation software? For instance, Foundation fieldbus “Virtual Marshalling” allows sensors to be added and deleted, and signals in these devices to be added and deleted at will because all I/O are virtual communication relationships piggybacking on the same pair of wires. Plants without digital instrument networking may have difficulty in the future to recruit new talent from the younger generation and to be commercially successful.

3D measurements such as for complex surface geometries such as solids level for piles of solids uses multiple sensors to already provide a detailed “insight” into the process today. It is digital because 4-20 mA cannot represent an uneven surface. The same goes for corrosion profiles etc. and could be done for temperature profiles as well.

Valve positioners are already networked using fieldbus. In the future, the positioner may be able to communicate with adjacent sensors such as pressure sensors before and after the control valve and with flow sensor to monitor for cavitation in real-time, turbidity sensor for abrasive particles, temperature sensors for thermal load, and corrosion rate to predict valve remaining life and recommend service. This would truly constitute a digital ecosystem.

With fieldbus and wireless measurement digitization will be done directly at the sensor. This enables digital networking from the very first meter.

For many Foundation fieldbus devices it is already possible to update the device firmware from a central location - even while controlling, without bumping the process. This enables devices to take advantage of new feature enhancements and stay evergreen.

What is really new with Industry 4.0 and Internet of Things is the development of new services and business models; the underlying digital networking for the sensors are the same; WirelessHART and Foundation fieldbus. For instance, equipment manufacturers can monitor their pumps, cooling towers, and blowers remotely provided these equipment have been fully instrumented. Similarly, a third party service provider already monitors condition of steam traps in a plant to help reduce energy loss.

These are just some examples of additional functionality provided thanks to bus and wireless sensor networking that I picked up from the roadmap and tried to put into context. Digital ecosystems based on digital networking enables process industries to see the same transformation as digital photos, music, movies, TV, telephony, news, and mail etc.

If you read German I recommend you read the entire document to get the full picture

Well, that’s my personal take on the roadmap. If you are interested in how the digital ecosystem is transforming process automation click “Follow” by my photo. Let me know what you think of this essay by providing your feedback below, and click “Like” if you found this useful.