Spotlight: WirelessHART – Wireless Solution for Sensor Networks in process industry

On 17th of September 2012, AutomationWorld reported the unveiling of Emerson’s IEC 62591 compliant WirelessHART interface for use with its remote terminal units. Emerson has targeted this interface at upstream Oil and Gas applications and believes that the WirelessHART should make the sensing network extremely flexible without compromising on the communication reliability. While this news of a process controls giant taking a leap of faith as far as adoption of wireless networking for building critical sensor networks may seem a big step in the process industry setups, for some of us who have been following this evolution, especially that of WirelessHart, aren’t very surprised.

From its first release in 2007 to now, there has been a terrific momentum of its adoption and in one direction. While one of the principal driving forces behind the protocol has been the process giant Emerson, there are others like ABB, E+H and Nivis who have joined hands to build products that are WirelessHart based. The phenomenal growth is also fuelled by the proliferation of wireless sensor networks by the process industry and while there is a competing standard by ISA (100.11a) which is marketed as a future proof standard, WirelessHART because of millions of existing connected HART based devices is growing very fast. More than 8,000 WirelessHART networks are currently installed in major manufacturing sites around the globe, tripling the number of devices from 12 million to about 35 million in the last 2 years, signifying the acceptance of the WirelessHART standard by the process automation industry.

What is WirelessHart and how does the protocol enable reliable industrial grade wireless communication?

WirelessHart is a wireless sensor networking technology based on Highway Addressable Remote Transducer Protocol (HART) and uses IEEE 802.15.4 compatible radios operating in the 2.4GHz ISM band employing direct sequence spread spectrum technology and channel hopping for communication security and reliability, as well as TDMA synchronised, latency-controlled communications between devices on the network. Each device in the mesh network can serve as a router for messages from other devices extending the range of the network and provides redundant communication routes to increase reliability. The Network Manager determines the redundant routes based on latency, efficiency and reliability. To ensure the redundant routes remain open and unobstructed, messages continuously alternate between the redundant paths.

If a message is unable to reach its destination by one path, it is automatically re-routed to follow an established redundant path without data loss. WirelessHART supports multiple messaging modes including one-way publishing of process and control values, spontaneous notification by exception, ad-hoc request/response, and auto-segmented block transfers of large data sets. These capabilities allow communications to be tailored to application requirements thereby reducing power usage and overhead.

What makes the WirelessHART protocol a promising technology?

  • First up, it is built on a solid HART standard foundation, ensuring that it addresses the basic challenges regarding handling process measurement and control problems. Also starting out with an established protocol reduces the risk of unforeseen problems with the technology or the development process.
  • The HART protocol fundamentally supports on-demand communication as it is needed, making it a good choice for wireless applications where long battery life is important against most other bus protocols which require continuous communications that drain batteries quickly. It also permits selection of the power option that best meets application needs. Example options include long-life batteries, solar power, line power, and loop power. Other measures that are used to reduce communication overload are Smart Data Publishing and Notification by Exception.
  • The onboard diagnostics in millions of installed HART devices mostly go unused because their host systems can’t access digital HART data. WirelessHART adapters unlock this ‘trapped’ data by providing a new communication path to asset-management systems, historians or other tools.
  • WirelessHART includes several features to enhance reliable communications;
    • Redundant mesh routing (space diversity): WirelessHART mesh topology with self organising and self-healing characteristics where if there is interference or other obstacles interrupt a communication path, the network immediately (and automatically) re-routes transmissions using path optimised, redundant mesh topology.
    • Channel hopping (frequency diversity): WirelessHART ‘hops’ across the 16 channels defined by the IEEE 802.15.4 radio standard to overcome interference in the ISM band. Automatic clear-channel assessment before each transmission and channel blacklisting may also be used to avoid specific areas of interference and minimise interference to others.
    • Time synchronised communication (time diversity):  All device-to-device communication is done in a pre-scheduled time window, which enables collision-free, power-efficient, and scalable communication. Each message has a defined priority to ensure appropriate Quality of Service (QoS) delivery. Fixed time slots also enable the Network Manager to create the optimum network for any application without user intervention.
    • Additional techniques such as DSSS technology (coding diversity) and adjustable transmission power (power diversity) also help WirelessHART provide reliable communication even in the midst of other wireless networks
  • WirelessHART employs robust security measures to ensure the network and data are protected at all times. These measures include:
    • 128-bit encryption prevents sensitive data from being intercepted
    • Verification where Message Integrity Codes verify each packet
    • Key Management where rotating keys can prevent unauthorised devices from joining or communicating on the network
    • Authentication ensures that devices aren’t allowed onto the network without authorisation

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Is it high time to innovate for brown-field markets?

Green-field opportunities have traditionally been the focus area for innovators. An opportunity for them to demonstrate how things can be made to work better, look better and do things that were difficult to imagine. This is especially true for installations involving heavy infrastructure. It is significantly easier to adapt new ideas, concepts and products when you are setting up a new plant or process from scratch. On the other hand, there is inherently a high inertia towards trying something new in brownfield installations.  This is because brown-field installations were originally designed for particular modes of production, with established practices and technologies, incumbent customers and competitors, supporting and specialized infrastructure, deep-rooted business relationships, and sometimes extensive government regulation. This reality has dissuaded potential “brown field” innovators, especially in the automation OEM market.

Things have changed. With the economic downturn and a paucity of green-field opportunities, industrial product OEMs are, albeit reluctantly, looking to find some opportunities in existing installations. They are not finding it easy, however, and especially for emerging markets, they are really struggling.

There are a few aspects to the challenge of innovating in brown-field markets.  First, the innovation has to fit and co-exist with the existing technical infrastructure. Sometimes the interoperability problems can be really overwhelming and overshadow the benefits.  Unless strongly supported by economics (ROI) and a strong intent, this alone can stall innovation.  Consider the case of someone trying to innovate HVAC control systems to make them energy efficient in brown-field buildings (in India).  The reality is that the engineering is so non-standard that it is impossible to think of a one-for-all solution.  New products and processes, designed for mature, established markets, must be gauged in terms of their overall potential in order to fit within the complementary systems that make up the rest of the infrastructure.

Second, Economics plays a even more significant role in brown field innovation. Benefits are incremental in most cases and ROI terms tend to be longer. There are efficiencies built over a long period of time in running plants in a certain way – which is tuned to optimum.  The benefits of having a trained work force and existing physical assets often used well beyond their amortization—thus providing incumbent competitors with extremely favourable economic terms.  Anything changing this optimized environment must provide especailly compelling advantages.

Third, and perhaps most signficant, there is the human factor of resistance to change and unwillingness to take risks in operational installations. Most operations managers tend to be production focussed and do everything that they can to maximize production, sometimes sacrificing long term efficiency and cost, and taking a short and mid-term view only.

Is there a reasonable method to ensure that sustainable and economically viable innovations are possible?  Can one really make a difference? Is there a business case?  We believe there is indeed a business case and product innovators have to take some realistic bets.

  • For a starter, one should be ready to get their hands dirty; it is not enough to model and design solutions sitting in air-conditioned development centres. Problems have to be understood closer to where they are happening and solutions thought of accordingly.
  • More often than not, there is not a one-size fits all solution for all problems, even the ones that look similar. One the ground, existing systems may not be standards used and there may be inter-operability issues. Engineering must be done based on the use case and for the purpose.
  • While the innovation process may replace some of the engineering systems and processes, the change must avoid disturbing the core operations. This will help in easier adoption and avoiding change related issues.
  • Brownfield innovation, more often than not, demands local presence and closer ties with an ecosystem that understands and supports the need closely.

Concept Realization Accelerated – Is Open Source Hardware for real?

A lot of us grew up programming on proprietary closed platforms and were firm believers that that was the way serious products are built. It would be an understatement to say that most of us were proved wrong about our (mis)conceptions about the power of community. Younger software developers can always claim that they always knew that Linux and open source software was the way to go. Hardware guys, at least we thought, take their skills more seriously and would not be drawn to something similar … never.  At least that’s what we thought till Massimo Banzi told us that things could be made simpler in the electronics world as well … by allowing the proliferation of low cost open source hardware platforms and enabling thousands of innovators to experiment, without having to worry about a very expensive hardware design process.

Manzi co-founded what is now very popularly known to product innovators as the Arduino project, a cheap, easy to use, open source, hardware platform.  Next time you have to do your own small control system in your lab, don’t bother designing your PCB … Arduino (and a few other ready to use open source hardware platforms) is all that you need.

Focus on the ideas … concept realization made cheap and easy.

While Arduino is without a doubt the poster child of the open source hardware movement there are others too … BeagleBone is another open-source single board computer that runs Linux. Because it’s a computer you can program your tests in any programming language you like, from C to the command line. Python, also open source, seems to be the most popular language for BeagleBone. Then there is the Raspberry Pi, which is a credit-card sized computer that plugs into your TV and a keyboard.  It’s a capable little PC which can be used for many of the things that your desktop PC does, like spreadsheets, word-processing and games. It also plays high-definition video. The developers want to see it being used by kids all over the world to learn programming.

And so on…

Most of these platforms have evolved to the extent that there are a wide variety of daughter board designs available that provide a wide array of interfacing capabilities.

While this movement might seem like one for hobbyists, there’s a larger world out there. Open source hardware enthusiasts will tell you that this will quickly prove to be a tremendous business driver enabling companies to move faster and be more agile than ever. Open Source hardware is a way of accelerating innovation.

Next time you hear something called Razdroid or the Android ADK (latter one released by Google … now that’s cool), ignore it at your own peril … this is Android on your $30 board.

Bio-inspired automation technology – limitless possibilities

Bio-inspired automation technology – limitless possibilities

The ingenuity of Nature has always intrigued scientists and has inspired generations of inventors to understand how natural processes work and to apply that learning to come up with innovative bio-inspired solutions.  We thought we would, in this blog, talk about some of the work that has been going on and the “bio” inspiration driving that research.

THE ANTS

A project developed at the MIT Artificial Intelligence Laboratory, the aim is to develop a community of cubic-inch micro-robots, which should form a structured robotic community and incorporate social behaivor in this community.  The robot is equipped with 5 different sensors including IR, food, tilt, bump and light.  The inspiration came from the natural Ant colonies.  From a technical perspective, it was developed to accommodate ‘n’ number of hardware in such a small volume (1 cu.in.).  The microprocessor was just 8-bit running at 2MHz with EEPROM, equivalent to the first IBM PC.  The important point to consider is that, it not only runs its own code, but in parallel is communicating with its environment and other robots as well, which creates complications.

SWARMs

The main goal of the project is to develop a framework and methodology for the analysis of swarming behavior from biology and the synthesis of bio-inspired swarming behavior for engineered systems.  The idea was developed by Prof. Vijay Kumar from the University of Pennsylvania, to answer some of the questions related to bio-inspired swarms: Can large numbers of autonomous vehicles, work in a group to carry out a prescribed mission with or without a leader? Can they change their roles working in some hostile environment?

The inspiration for idea was to develop the high end algorithms, control laws and hardware to perform specified tasks as well as switching decisions by communicating with other group members. For example, Control was developed based on Hydrodynamics models (where swarm is assumed as an incompressible fluid, which is again interdisciplinary), and algorithm for task allocation without communication..

DIVISION OF LABOR

Another similar project is underway at the Laboratory of Intelligent systems at EPFL, Switzerland.  The project focuses on the evolutionary dynamics of fixed and adaptive mechanisms from both an engineering and a biological perspective.  The aim is to reveal the complexities arising from multiple agent interactions, development of distributed control algorithms and comparing with the engineering explainations for the colonial traits observed in ants, bees etc.

Amid research, they developed a framework based on artificial neural networks for modeling task allocation which includes workers’ behavioral flexibility to stimulus and colony response to varying stimuli. The bio-inspired models create a new perspective to the task completion in teams by agent swapping.  Similarly, in other domains of team work, bio-inspired theories help in the invention of new models.

The above examples are presented to emphasize the fact that there are lots of theories still untouched in nature which can be applied to any domain.

There are numerous examples in nature where things have structural flexibility like leaves, skin etc. Along similar lines, researchers have developed soft actuators/sensors which are fabricated on a flexible sheet at the Wyss Laboratory in Harvard.  One of the uses of actuator/sensor is to calculate the stretching of material on which it is mounted.  Another example is in the improvement in communication protocols for communication between machines working collectively.  New mathematical models are developed for spatial relationship to indentify the relative position in the dynamic systems. Similarly, a new class of algorithms, inspired by swarm intelligence, is currently being developed that can potentially solve numerous problems in communication networks like increasing network size, rapidly changing topology, and complexity.

As mentioned earlier, there is no end to learning from nature … and the quest will go on.

Machine automation – revisiting the history

Most of the earliest automatic systems were developed in Greece, and one of them that survived is the “Antikythera mechanism” (150-100 BC) which was designed to calculate the positions of astronomical objects.   The next level of breakthrough was the first programmable machine, developed in 60 AD, by a Greek engineer called Hero (Article).  He constructed a three-wheeled cart that performed stunts in front of an audience.  The power came from a falling weight that pulled on string wrapped round the cart’s drive axle, and this string-based control mechanism is exactly equivalent to a modern programming language (Video).

The above examples are mainly presented to demonstrate “how the advancement in mechanization techniques” happened more than 2000 years ago.  The word automation itself comes from the Greek word Automaton (acting on one’s will).  It is used to describe non-electronic moving machines, especially those resembling human or animal actions.  From the examples available in literature, earlier motivation for automation was mainly for entertainment.  It was a point of pride for a town or kingdom to have these mechanical machines.  Many examples are available on the Wikipedia pages of Automaton (Ancient Automaton).

The era of automatons for amusement and pleasure continued till 17th – 18th century, when the need for automation during the “Industrial Revolution” or “Machine Age” was noticed.  With the invention of new energy technologies (steam engines, spinning jenny, water frame etc.), better systems/mechanism were developed especially around industries like weaving, milling, power generation etc. During the Industrial Revolution, the mechanization of systems reduced manual intervention and increased productivity. Hence, the main motivation of automation (apart from fun) was the development of productive systems in the vicinity of the similar technology. (Link)

Once the invention of the transistor occurred in the 1950s, numerical control of machines was possible and automation really began to fly.  The systems were transformed from open loop to closed loop with help of electronics.  Even systems started developing around electronics because it makes processes faster (eventually productive).  Quite surprisingly, the focus on mechanization shifted to electronics.  Purely Mechanical Systems were transformed to Electro-Mechanical systems, development of communication systems, and development of software domain started, and ultimately the invention of web services.  Because of development of such complex systems, the motivation for automation has branched itself into three parts, namely:

  • Automation for making process efficient – Examples from automated factories FANUC), where the light-out manufacturing started from 2001, robots are manufacturing other robots and the factory can run unsupervised for as long as 30 days.
  • Automation for making systems secure – Ballot box and ATM are the best examples where automation has helped the technology to work with security.
  • Automation for solving complex problems – There was a time when flight was very difficult, but with advanced automation practically complex, “Automated guided flight vehicles (unmanned)” are possible.

In recent years and in the near future, with the exponential development in Artificial Intelligence, complex algorithms, approaches to solve NP hard (nondeterministic polynomial time) problems, etc., automation has evolved into different levels.  There are also improvements in fabrication of micro-electronics components and along with flexible electronics technology, machines and automation can go to the miniature level.  In the years to come, the motivation for automation will be to make self dependent systems, self learning systems, systems which can work in teams and compact systems. Some of them are already developed like ASIMOs in research labs (Video). Upcoming areas for development (from practical perspective), are the robots/machines like equivalent to insects, animals, humans working in all terrains/environments, communicating with their similar machines.

Green buses in India – Are we asking for too much?

There was a recent news release from Ashok Leyland, the flagship company of the Hinduja Group, about plans to launch hybrid Optare buses in India.  While we know of some bold transit authorities in the U.S. and Europe running buses on hybrid power train, the news still appeared as more of marketing gesture rather than a serious business announcement.  Given the credibility of the company, however, we were intrigued to look at some ground facts on the possibility of serious application of hybrid technology in our mass transportation systems. Considering India offers a meagre 1.29 buses per thousand passengers, while other well-planned countries provide vastly more — Brazil has 10.3 buses per thousand — the opportunity of making an impact is tremendous.  Is Hybrid the solution?

The hybrid transit bus evolution got a big marketing boost at the end of last year with the iconic London Redbus being prototyped on a hybrid power train (with the underlying design from Volvo).  It is a different matter that there was a kind of an anti-climax, though, because the bus had to pull over as the system was not designed for long-haul use.  In another development, China got its first indigenously developed solar powered hybrid bus – which claims to prolong the Lithium battery life by 35 percent.  In India too, a lot of hype got created with the launch of the Tata Starbus.  While the future has to be green, the economics of these buses and the peripheral systems have to allow a hybrid bus service to work from a cost perspective.  (there is no point running a few buses like we may end up doing…just doesn’t make economic sense..) Costs may become a huge barrier for its adoption beyond some pet ministerial projects.

The hybrid buses (and most of them are based on very costly technology from a few players) are at least 30% more expensive than the best buses running on Indian roads. Then there is also a choice between the type of drive train, a series-hybrid drive train and a parallel hybrid. Series hybrids are recognized as being more suitable for start-stop applications and allow flexible packaging in comparison to a parallel system where the mechanical drive shaft has to be 1.5-2m away from the rear axle. Series hybrids are very sensitive to failure, however, and if any of the electrical components fail it comes to a complete standstill – unfortunately many of the new components are susceptible to this. Then there are the batteries, they are expensive, hazardous, very bulky, add significant maintenance cost and some need to be changed as often as every four years.

In the context of adaptation of hybrid buses for Indian public transport, I believe that there are few things that need to happen before it can start making sense. Better batteries, lower initial cost, a better ecosystem and more importantly economies of scale. India can also choose to wait till the next wave of evolution in hybrids.  For example, a new technology for charging electric buses has already been introduced in Europe called Opportunity Charging.  This economical technology helps in the contactless charging of electric buses — where the driver needn’t leave the bus for recharging. We will follow the evolution closely and hopefully play a part.