Like sonar, ultrasonic transducers can detect detailed qualities of surfaces by bouncing sound waves off them. Today’s sensors are cheap, compact and have a vast range of applications.
The simplest ultrasound detectors in use are passive microphones but the majority of applications use a transducer - a device that combines a sound emitter and echo receiver. They are tuned to frequencies above 18 kHz, therefore inaudible to the human ear. Sound can be generated in a variety of ways but the most common methods are piezoelectric and capacitive (creating an electrostatic field between a back-plate and a diaphragm).
The vast majority operate in a straightforward way: they measure the time lapse between the signal generation and the arrival of its reflection. This simple principle can be tuned and adapted to achieve an impressive variety of functions. Sensors can detect and record speed, weather, size, material levels, numbers of items, condensation, contours and profiles, distance or proximity. Their targets can be large or tiny, near or distant, stationary or moving. When fitted in mobile vehicles and containers, geolocation reporting is often incorporated onto the same devices.
Some of the uses of proximity sensors are familiar - such as reversing vehicles and intruder alarms - but they have far more potential. Detectors can calculate accurate distances to the intercepted surface. The basic formula is simple: L = 1/2 × T × C - (L being the distance, T the time between transmission and reception, and C the speed of sound). Variations in the speed of sound can be allowed for as required and many sensors can work underwater or within other fluids where sound propagates differently. Detected surfaces can be irregular or diffuse, such as wire mesh, yet the sensors are resistant to interference from mist or dust.
This principle allows sensors to monitor the level of material in tanks and silos, highly valuable for any business reliant on continuous feedlines or just-in-time reordering. Ultrasound sensors can be set to detect a concise point or to average a broad irregular field of objects such as those in municipal recycling bins. Despite irregular contents, ultrasound sensors can issue automated alerts to the collection or refilling company, ensuring perfect logistical efficiency.
Sensors are also being deployed to monitor water levels in rivers and reservoirs, facilitating river management, water supplies, flood control and protecting natural habitats. Similarly, they can monitor levels when filling boxes and bottles or the cups in a drink dispenser.
Speed cameras use infra-red but discrete ultrasonic transducers can apply the same principle to estimate the speed and direction of moving objects. There are a variety of ways to implement this; sensors can emit a series of pulses, calculating the change in distance over a given time, multiple sensors can triangulate in several dimensions, and (in principle) a Doppler effect could be calculated from pitch modulations.
Engine and motor speeds can also be safely monitored using discrete acoustic sensors.
A basic requirement on many production lines, acoustic sensors have no difficulty calculating the exact number of items that pass through an acoustic signal. Sensors can also sort boxes of different sizes, providing independent counts; useful for economic packing into delivery vehicles.
Some of the applications are surprising, for example linking a sensor to a rotating anemometer and/or weather vane can transmit constant information about wind speed and direction for meteorological purposes. Locating them at entry and exit points can ensure car park or building occupancy is not exceeded or that all personnel have been evacuated.
Medical ultrasound scanners are familiar, but profile sensing is now highly versatile and affordable. It can be implemented into semi-automated or robotic assembly lines, or to support shaping and finishing processes. A simple, but vital, application is to monitor stacking. They can also accurately monitor roll diameters and coil winding and unwinding operations.
The possibilities for acoustic sensing are vastly extended by transmitting the output from smart sensors across the “internet of things”. Multiple outputs can then be combined in a single sophisticated web-based interface and monitored in real time from any convenient location. Smart sensors can then be easily interfaced with microcontrollers and actuators to provide sophisticated remote control and record details into enterprise management software.
Many businesses have yet to realise the wealth of opportunities that come from linking smart sensors to the IoT. Off-the-shelf devices are cheap and unobtrusive. For more demanding applications, bespoke algorithms can be implemented in the device firmware or in software at the collection point.
Many businesses, not just factories, can benefit from sensors. They can monitor doors, count products, maintain temperatures, control production lines, automate stock records and optimise a host of other functions from the most simple to the most complex. They are cheaper and more capable than ever before: if you aren’t using them already you should be exploring the possibilities, but how you connect them is a key consideration.
Arguably, a door-bell is a simple wired sensor but a door bell can also be wireless. Even in the case of door bells, the best solution may be deployment-specific. Here are some of the key advantages and disadvantages to consider when deciding how to connect your sensors.
Quick, and therefore cheap, installation is often a decisive advantage in favour of wireless sensor systems. Wireless is frequently the only sensible solution in listed buildings or on sites already crowded with infrastructure. It is usually more viable when the site is split between several locations. Wireless connection easily causes less disruption to ongoing operations and less damage to plaster and floorboards.
In contrast, once you have paid for the equipment and installation, running costs should favour wired networks that do not need to lease bandwidth. Nevertheless, wireless IoT solutions are usually cheaper overall - as are future modifications, equipment relocations and network extensions.
A downside to connectivity is always the potential for intrusion or data corruption. IoT and Cloud solutions offer a range of protections and many come free - relieving you of a significant IT burden. Wired networks keep more points of vulnerability in-house, but are only more secure if you have personnel who know how to protect them. New security enhancements - such as SDN - can provide signal encryption and dynamic routing with minimal IT overheads.
Wired Ethernet networks are often a sound decision when all of your infrastructure is reachable. Wireless solutions have an obvious advantage if you need to connect remote equipment. If you are a utility operator, a farmer with multiple scattered assets, or a transportation company whose assets are moving, other options make little sense.
When your assets are in exposed locations, even inside a factory, remember that not all wired switches, routers and hubs are robust when subjected to extreme temperatures, moisture, grit, or power spikes. Wifi is therefore more reliable in harsh environments.
Wireless sensors are easy to replace or relocate without rewiring anything. You can also easily extend the network to incorporate additional operations, even when they are in a different building. Wired networks often require IT engineers to keep them running properly.
In contrast, wireless networks rarely require attention - they communicate over the Internet, which is maintained for you. Wireless technology makes it easier to benefit from upgrades and patches, or new Cloud software as it comes along.
By linking your devices using the IoT, your wireless network and Cloud resources can become scalable to fluctuating demands. If your production scales down, so does your consumption of bandwidth. If it scales up, extra capacity should be available on demand. With the right contracts in place, your sensor-control infrastructure can become a fixed and predictable percentage of your operating overheads. By comparison, a physical network always costs money to expand and returns nothing when it contracts.
Some wireless sensors rely on batteries. The advantage of batteries is that your wireless devices stay on and connected even in a power failure. The downside of batteries is that changing them usually takes a sensor offline (although this can be avoided using capacitive power storage). Conversely, wired sensors will always fail if their whole network fails or has to be powered down for maintenance.
Even in a total blackout, battery-powered wireless sensors continue sending your data to the Cloud via the IoT and you can continue monitoring them with your smartphone.
Any network issue could interrupt wireless services, so if 100% continuity is vital to your operations, a fall-back plan is important. However, wired networks are also susceptible to power failures and other interruptions, so backup plans could be needed anyway.
Electromagnetic interference from power lines is unlikely to affect physically wired equipment but sometimes causes a problem for wireless sensors. There are usually workarounds or shielding solutions for these local problems.
The choice between wired and wireless need not be either/or. A good IoT development team will help you to integrate wireless sensors with wired ones according to the issues in different locations - and enjoy the benefits of both.
The Environment Protection Agency recently declared that “Air pollution has a devastating impact on the UK population, shortening lives, causing early deaths and ill health. It is a bigger global killer than smoking. It costs the UK economy over £20 billion a year.” ( https://www.environmental-protection.org.uk/policy-areas/air-quality/air-pollution-law-and-policy/air-pollution-laws/.)
Common pollutants include ozone, sulphur oxides, nitrogen oxides, dioxins, polycyclic aromatics, carbon monoxide, ozone, particulates, ammonia, methane, hydrogen sulphide, chlorine, hydrogen chloride, hydrogen cyanide, phosphine and ethylene oxide. The consequences range from debilitating fatigue, headaches, hay-fever, skin disorders and eye irritation up to fatal illnesses including lung cancer, emphysema, asthma, COPD, bronchiolitis and cardio-vascular diseases. Polluted air has also been linked to mental illness, behaviour disorders, mental retardation and miscarriage.
The EU accused the UK of failing to comply with EU air quality regulations in 2017 ( http://europa.eu/rapid/press-release_IP-17-238_en.htm) and the UK government declared air pollution a national health emergency the following year ( https://publications.parliament.uk/pa/cm201719/cmselect/cmenvfru/433/433.pdf). A post-Brexit Environment Act is in the pipeline but it is unclear whether it will have any more effect than previous failed legislation.
Outdoors, traffic fumes overtook factory chimneys as the leading problem long ago, despite which many proposals for the new Environment Act still focus on “factory emissions” as did the last Clean Air Act in 1993. The proposals also largely ignore indoor sources of air pollution.
According to a study by the US EPA, indoor air quality is often 5 times worse than the air outside ( https://www.epa.gov/report-environment/indoor-air-quality). The main offenders are synthetic materials such as composite wood furnishings (which leech formaldehyde), synthetic carpeting, cosmetics, pesticides, office printers, photocopiers, asbestos-laden roof tiles, faulty aircon systems, domestic cleaning products, and (ironically) “air fresheners”.
Whether the new legislation addresses these problems or not, it is clear that employers, industrial facilities, office managers, local government and the public at large should be looking for solutions. We all breathe the same air and it is a significant hidden burden on our communities and productivity.
Most cities and towns have a few air monitoring stations, but their coverage is poor. They are also fixed in location (often the wrong ones) and the public have little access to their readings. As such they leave us a lot of guesswork.
Most people assume that pollutants rarefy as you get further from the source. That is not always the case - many roll into low-lying areas or form invisible clouds overhead that descend to ground level when the air temperature changes (for example at dusk). Air quality in specific areas can be substantially worse than thinly sprinkled monitors reveal. In short, to understand our air pollution problems and correct them, we need more monitors. That is equally true inside our homes and places of work, and outside in our city streets and countryside.
Before the IoT, better monitoring was impractical, but a wide range of air-quality sensors are now available. The IoT makes it easy to collect and monitor their data from almost anywhere. Detectors in fixed locations help us understand how conditions change over time, but we can also use mobile detectors to greatly extend our geographical coverage. If every council vehicle carried a monitor, blackspots would be discovered quickly and dealt with.
High-end devices are capable of establishing the parts-per-billion of a wide range of pollutants. Others focus on particular known hazards, such as nitrogen oxides or aromatics. At the cheaper end of the range, suitable for many domestic and industrial uses, sensors can provide a simple “red-amber-green” warning system about air particulates. They are increasingly popular with urban cyclists, and alert you to don a face mask.
The most common method for connecting an air quality sensor is a simple 3G or 4G SIM card. However, there are many systems for collecting transmissions. In some parts of the British Isles, notably Scotland so far, LoRa wireless networks are available. No matter how much sophistication you require in your sensors, the vast majority of systems report to a Cloud service where the data is accessible through a simple website interface.
Understanding the data you collect is made easy by proven off-the-peg tools such as the Tableau analytics platform. Visualisation tools make it easy to understand the results of your monitoring devices at a glance. If necessary, you can then cross-reference your readings with factors such as weather information.
The Breathlife2030 organisation has declared September 7th 2020 as the first “International Day of Clean Air for Blues Skies”. There is no better time to be looking at IoT air quality tools than today.
Commercial theft is not only growing, but for markets contracting after Covid-19, it is even more damaging. The majority of serious thefts are conducted by career criminals, but the Covid-19 lockdown affected them too, closing access to their markets and making them conspicuous on the roads. Now the lockdown is lifting, they will be as eager as anyone to make up for lost time.
Research from the Allianz Cornhill Insurance group reveals that claims arising from plant theft grew steadily between 2013 and 2017 and are believed to have continued rising since. Agricultural, construction and manufacturing sectors are all hit hard by the loss of major items of equipment: not only are the items themselves expensive, but their loss entails downtime, leasing replacement equipment and higher insurance premiums. Unwary victims have been known to make quick purchases of replacement vehicles only to discover that they too are stolen, leased or still on HP.
Break-ins also cause substantial collateral damage to gates, fences and garage doors. Just before Christmas 2017, a stolen Manitou digger was used to smash an ATM out of a station wall in Haslemere, leaving the station building unsafe. In many cases, the damage done by thieves seems to be purely senseless.
Most thieves are not nice people as evidenced by the 80,000 face masks and other medical PPE stolen from a Salford warehouse in May. The haul, valued at £166,000, was on its way to NHS hospitals and old people’s homes in West Yorkshire, an area with high Covid-19 fatalities among patients and medical staff. To reach the PPE, the thieves cut a hole in expensive steel security doors, probably with stolen cutting equipment.
Popular targets range from small electrical tools up to tractors, trailers, excavators and bulldozers. Fuel tanks, metals, roofing materials, aggregates and livestock are also popular. Immobilising vehicles only provides partial defence; some are simply stripped of valuable spares where they stand.
Different kinds of theft present farms, factories, storage depots and building firms with a range of different problems. CCTV, intrusion systems, impregnable fencing and human security patrols are all highly expensive and none are fool-proof against specialist criminals. Drones are now popular on large farms, but even more expensive than the drone is the labour of its human operator. The rising rate of theft demonstrates that most technological solutions have been ineffective so far, and once stolen the chances of recovering machinery are less than 10%.
The first step all farmers, building contractors, plant managers and fleet owners should take is to register their Industrial vehicles and large static machinery on national databases such as TER (The Equipment Register [1]) or CESAR (The Construction & Agricultural Equipment Security and Registration Scheme [2]). Rather than relying solely on the equipment’s VRN or serial number, which thieves will try to erase, apply and record your own unique and discrete security markings.
The main point of registration is to recover property, but it also helps to trap and convict the thieves. Registration is also a deterrent. Many thieves will think twice about taking items that are dangerous to sell on, so display a warning.
Another strategy that works very well for both registered vehicles and shipments of bulk materials is tracking them with a new generation of smart devices.
Today, almost any electrical or battery-powered item can be connected wirelessly to the internet. Once connected, you can communicate with it from any smart-phone or convenient computer. Tracking is a simple application, but you can also use the IoT to monitor or control your devices remotely. A connected device can also be designed to send you an alert if it is moved or disturbed in a way that it shouldn’t be.
The most common targets for thieves are portable tools such as chainsaws and grinders, levels, theodolites, BIM and GPS equipment. Favourite vehicles include breakers, diggers and excavators, generators and compressors. Farmers need to remember their trailers, horseboxes and quadbikes. There are ways to connect almost all of these items into the IoT. You can also tag your cargoes with discrete recoverable connected devices that will report their movements in real-time as they are moved around the country, or even if they are shipped abroad.
The imminent introduction of 5G connections will greatly accelerate the rollout of cheap sophisticated IoT devices, so this is a great time to review your security strategy.
