False alarms from safety sensors?

So I do know about sensors and control systems, from the supplier point of view. But maybe like many suppliers I’ve only been on site to troubleshoot a sensor that is reported to be giving incorrect data. So someone else made the decision to question the validity of the sensor outputs.

These days, the nearest I get to regular sensor monitoring is at home, typically with smoke alarms, a CO monitor, and a flammable gas alarm. Plus the plant manager, my wife, is always demanding an immediate solution to any alarm system going off, to continue production.

The problem

A flammable gas alarm was positioned above the gas hob: perhaps in retrospect not the best place, as the instructions said humidity and steam should be avoided. But very quickly we realised that the detector was not very tolerant of any wine added to dishes being cooked on the hob. Then, surprisingly, it alarmed whenever we had bread dough baking in the (electric) oven. Since the detector was said to be set to alarm at 25% of the LEL this was surprising.

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The instruction came down – ‘Get me a switch in that alarm circuit, so I can switch the piercing noise of the alarm off!’ So, there was my solution, and a task, so that was done. I did not think it through any further.

Time passes

This system worked well for maybe 3 years. The alarm switch changed power from the alarm to a lamp over the worktop, so we knew to switch it back on after a problem event. But such sensors must have a life, and so when the alarm started going off when the kettle boiled and steam drifted up past the detector, I thought the unit was failing. There were then several late evening alarms, for no apparent reason, and we could not smell any gas (it is difficult to detect these days), nor see anything untoward. Like every engineer I guess, I felt the sensor, to find it very hot. This seemed to confirm the problem, that the sensor was failing, so take the thing out – ‘it was not that hot before!’ Something had changed.

Six months later, this Summer, we had a new gas meter – a Smart unit – installed on the domestic gas supply. Ultrasonic measurement of the flow, wifi connection to the indoor display, and mobile network reporting usage figures to the supplier. That would all be great, except the fitter refused to reconnect the gas to the house, because of a slight leak detected indoors. We had to call out a plumber to deal with our in-house problems. Good job it was Summer, as that took over a week.

Finding the gas leak

The leak was located as somewhere in the piping to the gas hob. The plumber tightened up the connections under the hob, and repeated the pressure loss checks. Still a slight leak, but within allowable tolerances. OK, so he checks once more, to be sure, and starts his paperwork. A last twist of the 90 degree bend directly on the hob (supplied by the Chinese supplier) produced an interesting result: the threaded part of this connector sheared off, almost in two half-round pieces. It looks like steel, but low grade steel, and showed a brittle type fracture all around the fitting.

Presumably the crack that had been there before, allowing a slow leak, had led to the fracture on tightening the connection. That was installed 10 years before, and no-one had done any checks of that or the system post installation. OK, I had never had the systems tested for gas leaks.

What had happened?

The conclusion at this point was that the slow leak presumably collected gas in the lower cupboards, and when this escaped it combined with the wine vapours to trip the alarm. Possibly the steam from the kettle just accelerated the rise of the gas past the detector. The detector was presumably a Pellistor, and got hot because it was burning the gas off. The dough rising in the oven? I don’t know much about bread and dough – but the leak was directly above the oven, so maybe the gas and air, warmed from the sides of the oven, helped the gas rise up past the detector. If that fitting had actually failed totally one night, there would have been a major blast, as I had removed the gas detector.

We now have installed a new detector, further from the cooking (3 metres). Plus the old one is re-installed, as a back-up unit: it is working OK still, next to the boiler. The bad news: the new alarm went off last weekend, when simmering a Paella laced with white wine….

Yesterday the plant manager produced a batch of dough and made bread. Both flammable gas alarms went off, first the unit 3 metres away then the old reserve unit, now even further away in the utility room, with the boiler.

Legislation

In any rented accommodation the landlord has to have a gas system safety check once a year. Because we own our own house there is no such requirement, and the boiler service man, who checks the gas boiler and heating system once a year, is not required to, and does not include, a system gas leak test in his inspection.

Product or system failure?

The gas hob was made by Proline, and installed around 8 years ago by a registered installer. It was a Chinese manufactured unit supplied by Comet as a low-cost own-brand hob to many retail outlets in the UK. The 90 degree bend that failed was supplied as a part of the hob, the gas inlet port. It is not steel, it could be an aluminium or zinc alloy. It appears the design was such that this port could be stressed during installation or tightening, as the bend itself would not rotate to suit the angle of the delivery pipework. It seems the break was on the hob side of the fitting. A combination of a poor quality fitting and a poor design.

The flammable gas alarm seems to work OK in detecting natural gas, but is even more sensitive to alcohol vapours, bread and dough making, and using any window cleaning spray that has any hydrocarbons in the fluid. So beware of using them in a brewery, distillery, bakery, bread shop, pub, restaurant and so on!

There was undoubtedly a small gas leak, around the hob, which has now stopped. Possibly this was from the 90 degree bend fitting, which then completely broke apart on tightening the joint. It remains possible that this failure was an accident waiting to happen.

The domestic plant manager is none too pleased at the moment. So do I leave the sensors installed, take both or one of them away, or fit switches to suppress the noise and turn off the alarm(s)?

UV keeps bottled water safe

Hanovia UV has supplied Cott Beverages UK, based in Derby, with a PureLine intelligent UV system to keep its production process water pure.

PureLine range

In an increasingly regulated and safety-conscious market, legislation such as the EU Directive for Bottled Water 98/88/EC (1998) drives the beverage industry to meet ever more stringent standards of quality. Microbial growth due to contaminated water or ingredients can cause discolouration, off flavours and shortened shelf-life. The threat of contamination is further increased as manufacturers respond to demands for less chemical additives and preservatives. Effective microbial disinfection of the whole process is therefore essential.

To meet this requirement, Cott Beverages has been using Hanovia UV disinfection technology to treat process water used in the production process. The company decided to use UV technology to ensure final product security prior to mixing and bottling and has been very satisfied with the performance of the UV systems.

“The Hanovia UV systems have been easy to integrate, maintain and operate,” said Chris Prentice, site service engineer at Cott Beverages. “They provide us with absolute insurance before bottling by making sure that we are producing and maintaining a high-quality product, which is essential for our brand.”

PureLine UV from Hanovia is an intelligent system that is optimised for the beverage industry to simplify the treatment of water, sugar syrup, brine and even reducing chlorine and ozone. Critically, there are no microorganisms known to be resistant to UV – this includes pathogenic bacteria such as listeria, legionella and cryptosporidium (and its spores, which are resistant to chlorination). Unlike chemical treatment, UV does not introduce toxins or residues into process water and does not alter the chemical composition, taste, odour or pH of the fluid being disinfected.

UV is used for both primary disinfection or as a back-up for other purification methods such as carbon filtration, reverse osmosis or pasteurisation. Because UV has no residual effect, the best position for a treatment system is immediately prior to the point of use. This ensures incoming microbiological contaminants are destroyed and there is a minimal chance of post-treatment contamination.

UV disinfection systems are easy to install, with minimum disruption to the plant. They need very little maintenance, the only requirement being the replacement of the UV lamps every 9-12 months, depending on use. This is a simple operation that takes only a few minutes and can be carried out by trained general maintenance staff. The Hanovia UVCare training programme supports businesses like Cott Beverages to make sure servicing is carried out by certified engineers at all UK production sites.

Battery Energy Storage Systems help UK power efficiency

Nidec ASI, of Milan in Italy, part of the appliance, commercial and industrial motor business of Nidec in Japan, has won an order from the UK-based EDF Energy Renewables business for the installation and supply of a second Battery Energy Storage System (BESS), for use on the British National Grid.

EDF ER, a renewable energy developer, is a JV company between EDF Energy in the UK and EDF Energies Nouvelles in France. As a result of this new contract, Nidec ASI will act as an EPC (engineering, procurement, and construction) contractor to supply the 49 MW BESS system that EDF ER is building to serve the National Grid, the British electricity distribution company. The contract, which follows closely after an earlier large-scale deal for a 10 MW battery energy storage system (also for National Grid) makes Nidec ASI reach a 33% market share in the British BESS systems market.

As renewable energy resources are more widely used – to reduce the environmental impact of power generation – investments in battery energy storage systems are becoming increasingly prominent. These stabilise the power grid by temporarily storing any surplus electricity generation, and discharging the saved electricity during power shortages. Last November Nidec ASI delivered the world’s largest (90 MW) BESS system to major electricity firm STEAG of Germany. As a leader in the BESS market, Nidec is committed to stabilizing the world’s power grids and contributing to realizing a low-carbon society via the spread and expansion of battery energy storage systems and high-quality state-of-the-art equipment.

EDF West Burton 2

The BESS will be installed at the EDF Energy West Burton site in Nottinghamshire, pictured above, to support the UK’s National grid.

Technews Guide to Wireless

Last year, in July 2015, the Journal South African Instrumentation & Control, published by Technews.co.za, released a new title in their ‘Industry Guide’ series, this time covering wireless applications of instruments in control systems. With 44 pages of ideas and applications, and background to the application of wireless comms for the instrument engineer, this gave a really useful source document – in the long tradition of these industry guides on relevant topics. This wireless guide is still available as a pdf on-line from Technews.

I was lucky enough to be asked to submit a review article covering some of the more recent applications of wireless that had caught my attention at the time. All of these are still topical, and relevant, so the review is now published here, with thanks to Technews. The reason for resurrecting the article is mainly because more information has just emerged about the application for the vibration powered sensors originating from Cambridge University research, now in use on the Forth Road Bridge. The new info, from a recent article in The Engineer is added at the end.

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The Forth Road Bridge, in Scotland, with the suspension cables being monitored by wireless vibration sensors, powered by harvesting energy from those same bridge vibrations! 

Industrial wireless communications for sensor data and plant information is now available, proven on site, and built into Internationally accepted standards. Wireless links should now be seen as just another family of techniques for the plant manager or engineer to consider alongside 4-20mA loops, fieldbus networks, and data links. Most would accept that plant data can be ‘monitored’ over wireless as effectively as from these other networks: but the action resulting from the monitoring can also create a control loop.

To those who say that wireless links should never be used within control loops, it is appropriate to remind them that sludge blanket levels on settlement tanks have been monitored, and the data transmitted over a wireless link to control the de-sludging operations, for well over 30 years. Add to that a comment about the latest North Sea offshore gas platforms, where Fire and Gas Shutdown systems are now offered by Yokogawa, using wireless gas detectors, with a dual redundant wireless network to reliably transmit all crucial alarm data back to the logic system, alongside sensor health and battery status information.

So how else can the phrase ‘wireless sensor network’ cause a misapprehension?

That internet hype and Process Plants…?

The adoption of wireless as a plant tool has probably even been held back…. by the apparent hype and emphasis on the Internet, the ‘Internet of Things’, and ‘Big data’ networks monitoring lots of sensors – Sensors Everywhere. Financial Directors suddenly see enormous expenditure, hundreds of USD1000 sensors, mushrooming recruitment for expanded IT departments – and then they pick up the latest management articles forecasting major impacts from hacking and data breaches. No wonder they are sceptical even before starting to read a proposal.

From reports about many of the application examples quoted by the enthusiastic suppliers over the last few years, it appears that success in the application of a wireless based system has come to plant engineers who had a specific and defined requirement, a problem for which the engineer’s assessment showed that a wireless system provided the most logical and cost effective answer. But then, would you expect anything less from an engineer? The typical number of wireless sensors installed initially might be quite low, say a dozen or less: usually the cost justification is based on the problems of new wiring to these extra sensors on an existing plant.

Plant networks from the major suppliers

Inevitably in this competitive field, with many vested interests, it is difficult to find a non-partisan authoritative spokesman: so Ted Masters, President and CEO of the HART Communications Foundation, says (in a video shown on the Emerson website, entitled “WirelessHART: An Executive Perspective”)

“WirelessHART ….. gives users the opportunity to bring in valuable data that can be used in systems to help decision support, particularly in plants that are already installed and already wired. Now the ability to put a point anywhere and bring it easily into the system …… will ultimately yield better performing plants for users”

The video quoted above also features Peter Zornio, Chief Strategic Officer from Emerson Process Management, who paints their stance as totally devoted to ‘Pervasive Sensors’, ie sensors everywhere, monitoring the standard process plant parameters, but also gas leaks, steam leaks, corrosion/erosion, vibration, flames and valve activation, for example on safety showers. This is logical, from a sensor manufacturing company: and Emerson has been collecting a whole range of new sensors to create a family of, typically, add-on plant monitoring sensors. The clue then is in the name, WirelessHART: the network provides all the data you would get from a 4-20mA HART sensor, plus the battery status in the ‘wire-less’ sensor. Other suppliers have joined Emerson as WirelessHART enthusiasts and promoters: these are mainly from the wired-HART sensor manufacturers – like Endress+Hauser, Pepperl+Fuchs – but also include ABB and Siemens.

The ISA100 viewpoint

The alternative wireless sensor data network for process plants, primarily on offer from Yokogawa and Honeywell Process Solutions, is built according to the ISA100 US standard. Suffice it to say that the ISA100 and WirelessHART systems are incompatible, but very much the same as each other, same frequency 2400MHz, similar principles of networking between sensors. Yokogawa concentrate on collecting process sensor information, in the same way as WirelessHART, and have made their ISA100 sensor interface electronics available for any other manufacturer who wishes to incorporate it into their own sensors.

ISA100 has additional capabilities, in that systems can be configured to have a defined time response, and the network messaging can also “package” up electronic message data from the sensor, transmit it over the network, and reconstitute it in the original format at the control room end. So this is useful for sending rotating equipment vibration signatures, and other waveforms from sensor systems for analysis by proprietary electronic units. Yokogawa has progressed this so that they can attach an ISA100 transmitter to a standard HART sensor, even power it from their wireless transmitter battery if needed, and send the HART data back over the ISA100 system: a similar RS485 Modbus unit is also planned.

The Honeywell approach does seem to be defined by their wireless product family tradename, “OneWireless”: it presents a wireless network infrastructure for a process plant that can deal with all potential requirements, using ISA100 for sensors, wifi systems for on plant access and control by laptop type systems, phones and tablets, and the capability to incorporate security cameras and video streaming from engineer’s devices.

After understanding all this diversity, the whole lot, WirelessHART, ISA100, wifi and video transmission, all seems to go through on-site wireless access points and aerials that use Cisco hardware and technology.

The second wireless project

The first wireless project is a major step, and is likely to be driven by a pressing need, which justifies the initial investment – or is restricted in plant area coverage so is cost effective.

Possibly the plant engineer’s subsequent enthusiasm for any further wireless network technology comes when he then discovers that the wireless infrastructure created makes the next project easier, and more cost effective. However, this only happens when the network used suits the developing requirements for data collection and wireless communications on the plant, so hopefully the choice of the network adopted took this into account.

It does seem that many engineers who try wireless once are then converted, and go on to invest in further, expanded installations!

On-plant network examples

The amazing thing is, the examples quoted are all unique, driven by specific site requirements. Straight sensor monitoring is typically via WirelessHART. A simple justification project where the network avoided new hard wired connections across the plant for Health and Safety rule updates that required alarm monitoring of safety shower usage was maybe the first of many new applications. Leak detection on storage tank farms using sensors for hydrocarbons within bund walls was justified in a similar way, to meet environmental legislation. Other areas where hard-wired links are a hassle are rotating and transportable equipment, and construction sites: temperature sensors in rotating lime/cement kilns are ideal for wireless monitoring.

An application in the UK from Emerson Process Management illustrates the progressive adoption success with wireless techniques in an existing plant that initially appeared to present installation challenges. Barking Power is a relatively mature 1000MW CCGT power station near London, suffering from steam losses. A wireless project used Rosemount wireless acoustic transmitters to monitor steam traps for leakage, on a rolling basis round the plant. Quickly, a leak from a high pressure super heater steam trap was identified, which itself could have wasted GBP1400 of steam a day. A further 15 acoustic detectors were added to monitor vent valves that can stick during start-up, and also for relief valves that may not seat correctly. There were few problems with wireless communications even in the enclosed environment around the turbine hall. The battery powered wireless devices were easy to move around the plant to test new locations.

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Emerson WirelessHART acoustic monitor installed on a relatively inaccessible steam trap discharge line at Barking Power

Then, high vibration levels were observed manually on the gas turbine starter motor, indicating a major problem. New parts were ordered but the motor needed constant monitoring to nurse the plant through to the next maintenance window. A motor failure would have caused damage in excess of GBP200,000, but keeping the plant running for a further two days could accrue revenue of over GBP50,000. So an Emerson CSI 9420 wireless vibration transmitter was added to the network, and the motor instantly monitored for potential failure. Travis Culham, a Rotating Machinery Engineer at Barking Power, commented: “We concluded that if Emerson’s Smart Wireless Technology could be successfully applied on this challenging application, then it could be applied pretty much anywhere on the plant”.

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An Emerson wireless acoustic monitor on a vent valve at Barking Power

A major application for wireless sensors from Honeywell Process Solutions will be the new Shah Gas project near Abu Dhabi. Because of a high percentage of hydrogen sulphide (23.5%), the project is unique, and needs significant worker protection and monitoring of this poisonous gas. This has led to the development of wireless H2S monitoring sensors by Honeywell Analytics, which will incorporate a ‘worker’ location and communication system: this actually uses a triangulation system on the wifi network to provide location data. At the perimeter of the plant there was a requirement for further H2S detectors to protect the local offices, and provide a klaxon warning in the event of a gas escape. Again wireless communication was specified for each gas detection pole, with a 1 second response time guaranteed. Here by choosing star topology for the network communications and with the time determinism defined within the messaging, only the ISA100 system was able to meet this specification.

Wireless Data links

Data links to connect typically a single remote outstation unit back to a control centre offer a different set of applications for wireless. Many are associated with the oil industry, in terms of oil and gas fields, and pipeline monitoring. Others are for agriculture, or environmental monitoring, or water resource management. Founded in 1993, Freewave Technologies in Boulder, Colorado, claim to be a specialist in reliable wireless machine to machine (M2M) and IOT communications solutions, now having supplied over a million systems. It does appear that they have developed the industrial side of this US based business in parallel with a lot of defence/military work on UAV (unmanned aerial vehicle) data transmission, and now have 2400MHz systems available for markets which cannot use the US 900MHz frequency band systems. The product range can replace wired systems for Ethernet or serial data transmission, or collection, transmission and repeating of SCADA system data, or multiple I/O circuits, over a wireless link.

In agriculture, the use of unmanned autonomous machinery is growing for practices such as harvesting, mowing and spraying. In a citrus fruit grove in Florida, Freewave M2M systems allowed an operator to supervise several autonomous mowing and spraying machines, only intervening when the machine meets an obstacle it cannot handle. Transmitted images show the operator what the machine is doing, and hopefully what the problem is: he can then use the wireless link to take control and direct the tractor around and away, presumably re-programming the route to be used in future. In this test the tractor used GPS Real-Time Kinetics location systems to provide the basic navigation (with centimetric accuracy) of the orchard, and one base wireless tower enabled reasonable coverage of a 3000 acre site: small repeater towers were used to provide coverage behind areas of denser foliage and trees.  Simpler Freewave wireless SCADA transmission for a wide-spread water supply and sewage network has been installed for Parker Water and Sanitation across parts of Colorado. Here the major advantage is that the remote outstation can be re-programmed remotely, over the wireless link, avoiding the need for and delay caused by a site visit.

The use of wireless around the site on remote oil and gas well systems is quoted by Emerson and Honeywell, to save on site wiring, complexity and power. These use the WirelessHART or ISA100 systems quoted previously. But there are also packages for collecting data from such remote operation sites, supplied by Honeywell and others, with integrated solar panels trickle charging battery systems, then providing remote wireless data links.

The Big Battery question

What about the power supply for these wireless sensors? That has been the biggest question, and the current batteries are big too, making a fairly large sensor housing necessary. But this is the main area where technology is moving fast to catch up.

After five years of operation in Emerson sensors, the answer to this question is still that they are not seeing a significant demand for replacement battery packs. Yokogawa offer a two cell battery pack that is suitable for exchange in the field, even in a hazardous area. The pack, with enclosed lithium/thionyl chloride batteries that are available from standard suppliers, allows cell replacement by the user. But battery packs still seem to have a 7-10 year life expectancy: the life actually depends on the sensor response time the user requires. By the time the battery pack needs replacement, the current growth of battery technology will have provided a better cell.

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Commercial batteries for an intrinsically safe battery pack, which can be fitted on site to a Yokogawa DP cell

There are also some really interesting developments in energy scavenging power sources already. In the UK, Perpetuum developed an energy harvester that could power an integrated wireless vibration monitoring sensor, creating the power from a moving magnet within a coil. Subsequently, the company have split their vibration-generator unit from the harvesting electronics, so that the latter can replace, for example, the battery in an Emerson wireless pressure transmitter, and the Harvester part is mounted on an adjacent motor or similar -that creates some vibration. Then the harvesting electronics can also be used to collect other inputs, for example from solar cells.

perpetuum-intelligent-power-module-for-emerson-3051s-dpcell

A Pepetuum Intelligent Power Module designed to fit the Emerson 3051S pressure transmitter

This could be the next area where further developments in technology will impact the design of wireless sensors. From ABB, the TSP300-W wireless temperature sensor has a micro-thermal electric generator (micro-TEG, a form of thermopile) that can generate power from the temperature difference (>20⁰C) between the ambient temperature, and that of the process being monitored, whether hot or cold. This is used to trickle charge a Lithium battery, which will operate for ten years at least.

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A power module for a sensor chip, from Illinois

Research is coming up with even more novel power ideas like this. At the other end of the size spectrum, researchers at the University of Illinois have produced a lithium-ion micro-battery suitable for ‘on-chip’ integration, using 3D holographic lithography. New lighter batteries using sodium-ion technology are being developed by Faradion to replace conventional lithium-ion cells. Cambridge University researchers have taken the energy harvesting vibration sensor further, in order to produce small self-powered wireless sensors that can be stuck onto the Forth Road Bridge in Scotland, to monitor the effects of traffic vibrations in the suspension cables.

The next step

The recent big consumer technology changes have enabled the technology, with mobile phones producing the economically priced components, aerials etc. Better capacitors, energy scavenging, batteries will all emerge to make the sensors longer lasting. Standards and customers are making the suppliers work together, and they are chasing to satisfy the significant new market demand.

Probably the major limitation to further adoption of these wireless systems in any industry will be in terms of expertise – the knowledge and understanding needed to design and put the systems together. There will be a lot of opportunity for installers and engineers to develop expertise in these new and niche applications, and there should be plenty of new applications emerging! But for once, some of the easiest applications are on process plants, even in hazardous areas, as the products and packages available for these jobs are now established.

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2016 Update on the Forth Road Bridge:

The above text was written in July 2015. Since then new applications have been reported here on ProcessingTalk.info. But this month’s story in The Engineer gives more information on the Forth Road Bridge application: Jason Ford reported:

“Cambridge start-up 8power has signed a contract with Innovate UK to support the development of its vibration energy harvesting (VEH) technology, an advance with a range of money-saving sensor applications.

The contract funds a collaborative project led by 8power and supported by Costain and the Centre for Smart Infrastructure and Construction (CSIC) at Cambridge University. It aims to develop a sustainable, scalable business case for the deployment of sensors in a range of industrial, infrastructure and construction applications.

According to 8power, VEH employs parametric resonance to facilitate power generation from a variety of vibration sources including motors, moving vehicles, or traffic-induced movement in structures such as bridges.

In October 2016 8Power was named the winner of the 7th Discovering Start-ups competition, which is organised by Cambridge Wireless.

Speaking at the event, Dr Antony Rix, 8Power CEO said that advances in wireless technology are making it easier to monitor a range of variables but that the acquisition of data requires large batteries or regular battery replacement.

“Our team solved this problem by developing a fundamental, patented innovation and a technique called vibration energy harvesting, “ he said. “What we do is take vibration energy that’s naturally there in the environment and turn it into electrical power.”

He added that the conventional – and inefficient – way of doing this is to swing a mechanical resonator from side to side, moving a magnet through a coil to generate electricity.

“What we do instead is move the anchor point up and down and this creates massively more energy and that means much more power, about 10 times more than our competitors…as a result the 8Power technology can enable this technology to power sensors in a much wider range of applications where the batteries of our competitors simply can’t compete,” he said.

forth-road-bridge-in-scotland-with-suspension-cables

“Trials of the technology on the Forth Road Bridge have demonstrated that the solution works in live conditions.”

The latest Robots are Friendly

We all know what a robot is. But then it really does depend on whether you immediately think of them in ‘sci-fi’ films, or paint spray booths, or welding on automotive production lines, or stacking in automated warehouses. These have been the big applications, in big automated factories, with around 240,000 robots sold last year. The article below was for a column published in the November issue of South African Instrumentation & Control, see a digital copy on http://www.instrumentation.co.za/archives.aspx

The emergence of the cobot supplier

However, there is a new breed of robot now: collaborative robots, or cobots, have only really emerged as practical devices in the current decade. A cobot is a robot that is intended physically to interact with humans in a shared workspace, so the special pens and protective light curtains around the robot operating area are gone. The cobot is designed to work alongside a human operator, typically maybe lifting the heavier items involved in electronic device assembly operations: it has smooth surfaces with no sharp edges, and protected joints, so a human working alongside cannot trap their fingers, plus it stops at the slightest external touch.

Additionally, the cobot is flexible, it can be trained (taught) by the assembly operator, by guiding its arms and grippers to show it what to do. Currently the cobot market is around 5% of the total, $100 m last year. These robots are lower in cost, say $24,000 each, but are aimed at the small to medium sized companies that account for 70% of global manufacturing, where flexibility is essential. New international standards for their safe design and use are emerging, and there are many suppliers, as the market is forecast to be $1Bn by 2020.

ABB’s YuMi

yumi-robot

One such product is the ABB YuMi (‘you-me’) desk-top robot: a dual-arm small parts assembly robot that has flexible hands, incorporates parts feeding systems, camera-based part location and automated control: yet it has twice the reach and more strength than an operator. It can collaborate, side-by-side (or across the bench), with humans in a normal manufacturing environment, enabling companies to get the best of both humans and robots, working together.

In April, the ABB YuMi was recognised for outstanding achievements in commercialising innovative robot technology with the prestigious Invention and Entrepreneurship Award at the Automatica trade fair in Munich. There followed a Golden Finger award as ‘one of the best industrial robots of 2016’ at the China International Robot Show in Shanghai. One out of every four robots sold today is sold in China, which is the world’s leading robotics growth market: 68 000 units were sold there in 2015, 17% up on 2014.

YuMi was specifically designed to help consumer electronics meet the challenges produced by the need for customised personal electronics products, by enabling operators and cobots to share tasks, with easy training when the task changes. The YuMi appears to be targeted at the assembly operations common with electronic equipment, significantly in Southeast Asia.

Universal Robots – another successful start-up.

Universal Robots (UR) was formed in Odense, Denmark in 2005, with the goal of making robot technology accessible to small and medium-sized enterprises. It introduced its first cobot in 2008, and particularly focused on food industry applications, with 3,5 and 10 kg payload cobots. Their average payback period of 195 days for customers is claimed as the fastest in the industry.

Recently its cobot arms have been awarded certification for use in clean room applications, so UR robots can now be used in areas where purity and hygiene – such as particle emission, easy-to-clean surfaces and extreme reliability – are decisive criteria for precise automation processes. This opens up more applications in the food industry, in the production of microchips and semiconductors, and in the electrical and optoelectronic industries.

At the end of 2014, more than 3500 UR robots were installed worldwide: currently they claim the figure is 6000 – annual sales maybe growing x2,5 in just over a year. Mercedes-Benz has replaced old robots with humans on some lines, to better manage customised products. They are moving to having production workers guiding a part automatic robot. Scientists at MIT, working with BMW, have found that robot-human teams can be about 85% more productive than either of them, alone. Subsequently Universal Robots were rated #25 on the MIT Technology Review’s list of the world’s 50 smartest companies: Teradyne Inc then acquired UR for $285 m in 2015.

Noise mapping offshore using wireless sensors

Many of the latest technology developments in relation to offshore oil and gas production installations have emerged from Norwegian research studies, because that industry represents the major part of the economy in Norway.  Such research studies do not only relate to better and more efficient methods of working, but they also investigate the health and safety aspects of the industry: an area of particular concern has been hearing damage to workers offshore, which is the predominant cause of work related illness. At the Yokogawa User Group meeting held in Budapest in May 2016, Simon Carlsen of Statoil ASA in Norway explained the background to a recent project that was undertaken to improve the efficiency of the noise surveillance and monitoring systems Statoil use offshore. This was also presented to a Society of Petroleum Engineers International conference on Health and Safety in Stavanger in April (Ref 1).

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The main Health & Safety tool used for monitoring noise exposure is the ‘Noise map’, which provides noise level contours within rooms and around machinery where workers are active. These are used to establish a course of action where noise levels exceed allowed limits, whether this action is to reduce or remove the noise source (if possible), insulate the area, issue PPE to workers, and/or impose working time restrictions. Noise maps have historically been based on manual surveys that take single point readings, which are then plotted onto a site map, typically from CAD drawings. Manually taking and plotting these measurements is arduous and time consuming, and typically would be updated only on around a four year cycle. Plus the readings are (obviously) not continuous, only record the conditions when each reading was taken, and generally do not record the added effects from workers using different machinery and tools in the area.

Statoil R&D on wireless & noise instrumentation

Simon Carlsen of Statoil joined the R&D Department in 2006, bringing expertise in wireless instrumentation, and started investigating the feasibility of using wireless sensors and software techniques to create a real-time noise map. The system subsequently commenced became known as WiNoS, for “Wireless Noise Surveillance”, when formally initialised in 2013. This will consist of a network of wireless noise sensors, continuously monitoring the noise in the process area, using sound pressure level (SPL) measurements of four types: A-weighted SPL (I.eqA), C-weighted SPL (I.eqC), peak SPL (I.peak) and thirty one separate third-of-an-octave frequency band measurements from 25Hz to 16kHz. This data is much more comprehensive than the simple noise level measurements used to establish the noise maps, but will superimpose this data onto the historically available maps. These readings can then be used to update the map in real time, and create alarms available to operators.

The WiNoS sensors then use an industry standard wireless network infrastructure, which transmits the data into the control system, where special software produces the updates to the noise maps – typically on a one minute update rate (ie almost continuous). This live information can be used to create alarms to report back to workers in the area, to control their noise exposure. The objective is to reduce work-related hearing damage, by knowing the actual on-site conditions; to optimize operator time working on/near tools, to reduce daily exposure; and to provide instant feedback on the effect of noise reduction measures. In addition WiNoS allows for time synchronized measurements amongst the sensors in the network, and also allows the control room operator to trigger a download of a high resolution frequency spectrum waveform from any sensor of particular interest, to analyse the signature of the noise. This latter is a major part of the future development of the monitoring system, which will feed into plant condition and process performance monitoring studies.

noise-map-3

The WiNoS project development employed the expertise of the Norwegian companies Norsonic AS in the microphone design and the sound level measurements, and the Department of Acoustics at the research company SINTEF to develop the PC software that records the data and creates the noise maps. The software was also required to conform to the Statoil qualified communications protocol.

Choice of wireless network

A major part of the research feasibility study that preceded the WiNoS project was devoted to the choice of the wireless network to be used to efficiently and reliably transmit the data, relatively continuously from multiple sensors. The two suitable networks that were emerging at that time were WirelessHART and ISA100.

The WirelessHART system is now well-known and fairly widely used in Statoil facilities, but the early research trials showed mixed experience with the system and the relevant vendors – some of this was related to the lack of specification details written into the WirelessHART standard. But there were also challenges with achieving the power efficiency in the transfer of all the data required, and the requested large data transfer of the high-res waveform was not readily achievable.

The ISA100.11a wireless transmission standard was also in use in Statoil, and had been adopted for the wireless flammable gas detector pioneered by GasSecure in Norway – Statoil had been involved with the prototype field trials offshore. The initial trials on ISA100 equipment from Yokogawa provided high flexibility for the different application demands, allowed all the 31 one third octave values to be packed into one transmission telegram, and allowed a well-defined block transfer. The sensor could also achieve the two year life required from the installed battery pack, at the 1 minute update rate.

The decision was made that ISA100.11a was to be the preferred protocol for WiNoS, from a technical and project model perspective. Based on the earlier experience of development co-operation with Statoil, it was decided to invite Yokogawa to join the WiNoS project as a Co-Innovation partner, a role that they were keen to develop. In addition to providing the ISA100.11a wireless interface electronics for the sensor, and the interface into the third party control system, Yokogawa worked with Norsonic to develop the mechanical housing for the microphone sensor, and the electronic hardware to process the sound measurements using the Norsonic software, with the whole sensor assembly meeting ATEX requirements.

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A Yokogawa wireless temperature transmitter adapted to include the Norsonic microphone

Full system test

In March 2016, a network of 7 off Yokogawa ISA100 enabled wireless noise sensors were tested within the (land-based) industrial lab hall at Statoil Rotvoll, in Trondheim, which has dimensions 35x25x15 metres – and contains various pumps and process equipment. Further synthesized test noise sources were created using loudspeakers. The wireless sensors, the noise mapping software and the IT backhaul architecture all operated reliably and successfully.

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Dynamic noise map generated with the system test

 

A further test, offshore on an operational Statoil platform, is planned and scheduled for Spring 2017, for which Yokogawa will supply 20 production sensors and the ISA100.11a wireless system. A typical platform deck of 50×50 metres might in practice require around 12 noise sensors for effective coverage.

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Possibly future noise mapping sensors will be added in high noise plant areas

The Statoil WiNoS system is now ready for development into a commercially available product for use as an offshore platform noise mapping tool. Future research on this system will involve investigation of 3D noise mapping systems. Statoil consider that the equipment application has potential for expansion into machinery condition monitoring, to include automatic process upset or fault and leak detection.

© Nickdenbow, Processingtalk.info, 2016

References

 

Water Use Cut 75% at IoT Connected Farm

Avocado trees monitored around the clock by a Spirent Communications system are given water only when needed; the farmer uses soil moisture meters, IoT technology, LoRa WAN communications and cloud computing to control the irrigation, reducing his annual water consumption by 75%.

It takes 74 gallons of water to produce one pound of avocados, and drought-stricken California produces 95 percent of avocados grown in the United States. Nearly all are grown in Southern California, in a five-county region that straddles the coast from San Luis Obispo to San Diego. Like the rest of the state, the southern coastal region is locked in a drought and largely cut off from the flow of surface water from the state’s big irrigation projects. Avocado groves have been hit badly with sky-high water costs and reliance on water pumped from underground aquifers.

Water consumption is regulated in California with the state entering its fourth year of drought resulting in water regulators imposing sweeping and draconian restrictions on the use of water. The State Water Resources Control Board has even urged Californians to let their lawns die.

Some avocado farmers in California feeling the heat have turned to new methods in growing avocados such as higher density planting which enables some to produce twice as much fruit for the same amount of water. But a new initiative from Spirent Communications in bringing about connected avocado farms might just be the perfect solution to make further inroads into lowering spiralling water costs.

Useful day-job expertise

It just so happens that Kurt Bantle is a senior solution manager at Spirent Communications and at home has some 900 young avocado trees planted in his “back garden” in Southern California. Within his work remit, which is to develop Spirent’s IoT offering, he decided to experiment into how avocados could be grown using less water through soil moisture monitoring, by using this as an input to automate the irrigation, using a just-in-time approach.

Bantle divided his farm into 22 irrigation blocks and inserted two soil moisture measurement units into each block. The units contain a LoRa (www.lora-alliance.org) unit for narrow band data communication to a LoRa gateway which has a connection via a broadband cellular uplink.

The gateway also contains an Oasis (a partner company with Spirent) re-programmable SIM which becomes the enabler in remote water provisioning. All soil moisture data from the avocado trees is collected in a cloud and visualised by a presentation layer. When a tree needs to be watered, the solution turns the sprinklers on automatically to get the correct level of soil moisture for each tree. It then turns them off when the correct moisture levels are reached. The connected trees are monitored constantly day and night. In all Bantle spent $8200 for LoRa stations, gateway and cellular backhaul, moisture sensors, and irrigation valve controllers.

“Avocado trees typically take 4 acre feet (1 acre foot = 326000 gallons) of water per acre per year. This is not only to supply the needed water, but also to leach the salts which build up in the soil,” says Bantle: “The soil moisture sensors let me drastically reduce water usage by telling me when to water and how deep to water to push the salts past the bulk of the rooting zone. The majority of the roots are in the top 8 inches of soil so there is a sensor there and one at 24 inches so I can see when I’ve watered deep enough to get the salts out of the rooting zone”.

The previous annual cost of watering his 900 trees was $47,336. By connecting this IoT technology, his annual bill dropped to £11,834, a 75% reduction. The hardware investment was recouped in the first 6 months.

“The case study showed a water usage reduction by 75%, but the usage will climb as the trees get bigger. The goal is to reach a 50% reduction of water usage when the trees are fully grown. By keeping the salts in check along with keeping nutrients supplied, stress on the trees is reduced and they are able to have better crop production,” says Bantle.

Future Consequences: both positive and negative

The downside for Bantle in harnessing the power of IoT to reduce water consumption was that he was placed under state surveillance for suspected meter tampering, when his water consumption reduced so dramatically.

The connectivity solution provided by Spirent together with its IoT ecosystem partners for avocado trees applies to every other type of vegetable and fruit farm, which would include almonds, olives, apples, oranges and tomatoes.

IoT technology pioneer Spirent Communications plc is leading the charge with its open eco-system partners such as Oasis Smart Sim through its connectivity and embedded subscription business and recently showed various such connected solutions at the IoT World exhibition.

Spirent’s Embedded Connectivity solution will be launched during 2016 in a phased manner so that the commercially available solution conforms to the corresponding GSMA specification releases.

Spirent conclude with the message that the Internet of Things (IoT) is destined to touch every aspect of human endeavour making factories smarter, supply chains intelligent ….and now farms such as this first IoT connected avocado farm more water efficient, saving farmers vast amounts of water (and therefore money) in the avocado growing process.

The original story from Spirent was first published by WaterActive.co.uk in their July issue.