Sensors and Actuators

Making sense of the millions of sensors

If there is one industry which is flourishing in modern times it is within the manufacture of sensors and actuators. We may live in the digital age but at some point we will need to measure analogous data, whether X-axis, Y-axis, Z-axis positions, temperature, humidity, Ph, salinity, distance, time and the list goes on. If a microphone is a sensing tool then we can see the loudspeaker motor circuit, the voice coil and magnet as being an actuator of sorts. The core rationale behind this would be a circuit, possibly a closed feedback loop, an audio amplifier, pushing the loudspeaker cone out synchronized with pressure acting on the diaphragm of a dynamic microphone. In this case the magnitude of excursion is the result of amplification factor from input to output.  The result here is done through an analogue process.

IR Sensor
Infra Red Sensor Transmitter

The microphone makes a good example of a sensor which could be used in the measurement of the Decibel. If the output of the amplifier were to be rectified and sent through a switching circuit designed to activate a relay at a preset voltage level, it could be used to warn workers that their working environment was conducive to hearing damage.  In practice this circuit would be used to switch on home lighting when a person performs a hand clap, a rather popular circuit in the 1970s and now seen as gimmicky.

Sensors are used in our everyday lives, from the time we open the door of a car or house to toasting bread, fridge temperature and maintaining aircraft altitude, speed and direction.  In mission critical systems computing systems rely on data from hundreds of sensors, many duplicated for redundancy and reliability and all designed for a specific purpose. As of present motor vehicles do not necessarily have back-up systems except in braking but this is changing. Even with all this technology many vehicles on the road still do not even have a means to tell the driver whether a tail light / brake bulb has failed.  For the casual reader an article on sensors and activators may seem rather ho-hum but in reality they play a vital role in how we use technology. In many instances we have had the technology to get a result but it gets shelved until such time a sensor can be made to work, and work reliably.

A typical example of this would be cameras, consumer or CCTV surveillance. Low light technology has improved in leaps and bounds over the last 10 years but yet is nowhere as good as where it should be. Doing a search on Google to find out the most common problem in modern cars will always return a sensor problem. Yes, they are reliable but the interesting fact is that even with modern technology, we use old technology to determine which sensor is bad. Very few car engine electronic control units return the exact cause of failure yet one faulty sensor can cause the entire engine to become a useless lump of aluminum.  Sensors are not only used in industries which affect our everyday lives however.

Every year technologists, engineers and scientists gather at sensor and activator symposiums, ICSTs (International Conference of Sensor Technology) and other advanced fields which recognize the importance of sensing in electronics and electrical circuits. Green energy and e-Agriculture two fast growing sectors rely on data input to improve efficiency, one to get maximum yield from as little light or wind and the other, crop yield. An interesting study on solar energy revealed that many PV cells have been placed incorrectly on domestic dwellings. Like an audio enthusiast would ensure that the acoustics are 100% in his or her audio room through tests using sophisticated equipment one would have thought that a proper test would be conducted to get maximum yield from the sun.  One should rely on the winter sun and not always readily available energy. This just did not happen. Now, with a more commonsensical way of doing things hopefully engineers and architects will start redesigning our modern human caves to be more in line with modern energy requirements and not necessarily the looks of a house. Sensing circuits play a vital role in this – statistical data: wind speed, wind direction, sun altitude, temp, snow, rain – all at different times of the day, week and year.

Sensors, and quoting from Wiki “is sensitive to the measured property, is insensitive to any other property likely to be encountered in its application and does not influence the measured property.” Although this more or less sums it up, wiring and electronic circuit performance plays a very important role, usually through placement (altitude, vibration, air, sea etc), temperature ambience, noise (and noise temperature), soldering type, shock etc. Input through sensing needs to be critically tested and not just those used in the medical and space/aviation sectors.

As with sensors, actuating mechanisms need to be evaluated within the working environment. Something as simple as a starter motor solenoid has been known to fail in certain brands because of the above norm temperatures encountered. (exhaust manifold springs to mind). Although the electronics used in many “feedback” systems has proven to be reliable, actuators have been known to fail under harsh conditions, the aviation and maritime industries especially.

Volcanic ash is a typical example of an extreme condition; acidic, clogging and a fairly good electrical conductor in large amounts, enough to create a flashover.  Early warning systems for volcanoes, tsunamis, tonadoes, hurricanes all use an array of sensing devices, the actuators driving circuits to propagate information through radio or fixed lines. These sensors and actuators can supply us with all the data we need but we still rely on fast and ready computation. The MH370 wreckage is believed to be somewhere around Reunion yet no radar or radar system picked up enough data to pinpoint it’s movement.  This was not a small aircraft, radar systems are extremely sophisticated compared to those used during WW2 but yet we were oblivious to it’s movement. Or were we? More about radar engineering and aperture sensors here.

Robotics make extensive use of sensing devices and actuators. Automation in the factory, conveyor belts, hoists and lifts, servo feedback, biometrics, microwave ovens, kettles and cookers, even the most primitive type rely on data input to operate correctly and safely.

The more critical the application, the more expensive the sensor. So we go with the normal train of thought but yet interestingly enough, from GPS co-ordinates, re-routing of traffic and climatic conditions, smartphone data is playing a vital role in this. Smartphones are becoming more equipped with sensors which allow the user to get direction, g-force, SPL and a host of combinations which are not lost in the scientific world. Already car manufacturers have apps which connect to the smart phone for monitoring the dozens of computers on board the vehicle. TomTom and Garmin not to be outdone by the Smartphone GPS receiver are directing their resources into health.  Data can be sent to a central medical call-center which can detect problems in blood pressure and breathing of listed patients, the IoT will make this easier.

All because of sensors.


Computing is all in the Cloud

The Cloud is The Future

Sir Charles Darwin, head of the National Physical Laboratory and grandson of the famous naturalist wrote in 1946 that “it is very possible that one machine would suffice to solve all the problems that are demanded of it from the whole country.” Although Thomas Watson, IBM Chairman and CEO has been credited with the statement that we would only need 5 computers, this has never been proven. To a certain degree this prophecy is not all that far fetched.  Processor power is dirt cheap and hand held devices of today yield more computer power than their predecessors of the late 90’s, hooking your hand-held onto the cloud has made them more powerful.

Cloud Computing WPC 2015
The Microsoft WPC 2015 in Orlando – Live appearance

Many experts believe that Moore’s Law no longer holds, processing power just cannot be doubled every 18 months unless we make a giant leap forward in quantum physics. Another ominous signal is that manufacturers, distributors and resellers are fighting in a market where margins have dropped to a point where nobody wants to remain competitive. Five years ago a tablet costing 800 US Dollars can now be purchased for about 200 Dollars. We are not just running out of margin, we are running out of innovation. Government raise serious concerns about the landfills.  The very idea of Azure and virtual machines is nothing new. Taking the host of problems mentioned above as a starting point the cloud is starting to become a very attractive alternative. In fact, right now it is the only alternative. In a rather bizarre twist, perhaps IBM and Sir Charles had it right.

Harbingers of doom and gloom will bring out two aspects to hosting service over the internet which although certainly true must be carefully analyzed, one being security and the second, access to the data center. The reality is that in most cases Cloud storage is certainly more secure than how most companies currently secure their data via mag tape, disk, fixed disks etc. This data is almost always either stored off site and as a secondary measure, kept in-house. It’s uncanny that when servers do go down there is almost always an issue in running the backup. Companies always have a UPS at their disposal but only when the power goes down do we realize that the batteries have not been checked for two years and the server crashes, usually spectacularly. Cloud is supposed to be idiot proof in this regard. Backups, encrypted data and redundancies. Which brings us to the number two: data access.

Cloud Computing - partners at the Microsoft WPC 2015
Catering for 16 000 partners at the Microsoft WPC 2015 in Orlando, FL

Data access through the internet is almost certainly via some form of fixed line. Losing access is a problem either through copper theft or a glitch at the local exchange. Third world telecommunications is not known to play a significant role in the national budget. This is changing however as optical and wireless becomes a predominant player in connecting users to the exchange. There are limitations however – time and finance. Another big factor, affordability for users. Many providers charge for their services in US Dollars and the Euro. Although we rely on companies such as Microsoft to provide all your security needs how do local cloud providers fair in this market? The argument about trust and data security again although the services are cheaper.

Third world countries have serious limitations when it comes to supply (power) and fast network connections. In South Africa for instance, copper theft is rife, the local power utility is under huge strain due to inept management and lack of maintenance. (as an aside it’s interesting to note that the SA government consult with Indian energy providers where they too have possibly the worst outages of any country globally). SA telecomms giant Telkom recently laid off thousands of their most experienced workers.

The plus side to all this of course is that big business will put pressure on fixed line operators to pull finger and re-evaluate priorities. As most parastatals and private telecomm giants see big business as their main source of revenue this is spilling over to the small to medium business market, many of which are home run. This should cause additional pressure on providers to supply reliable, cheap and fast fixed line installations.  In the U.S.A. and many parts of Europe reliable telecommunications and power utility form the backbone of most industries and fixed line operators supply very good value. Anti-collusion and aggressive competition allow for this.

In the mobility sector, hand held devices such as tablets and cell phones are being used more and more in business and having access to big data is just making these devices more indispensable. Besides controlling the largest amount of data centers near globally Microsoft has embraced Linux, testament to their commitment to Cloud computing and open software solutions.  Office 365 is becoming a major player with an expected growth factor of about thirty percent through the next fiscal year. Sharepoint has become not just a catch phrase but is the ideal way to manage and share data. Dynamics CRM is possibly the most vital way to keep in touch with your clients requirements.  Skype for Business is now not just an add on, it’s an integral part to our daily business lives. Yammer, off the O365 suite is the enterprise social networking platform.  It lacks the excitement of Azure, CRM, Sharepoint but as users become more used to the Office 365 suite it will gain in popularity. Microsoft is not known for making things simple, their technical writers should use more fun illustrations – who reads past the first paragraph anyway?

The WPC (Worldwide Partner Conference), July 2015 in Orlando was a sure indicator of the power behind Azure and which direction business worldwide is going.

The cloud may stymie growth in the hardware sector (as is claimed, but not proven) but it will influence the growth in other areas (eTail, commerce, communication, etc). We are now entering the invisible spectrum and hopefully less wastage, which is good for our landfills and great for software engineering. It will increase profitability through efficiency and relationship building, whether on the phone, intranet or internet.

(Ed’s note:  For any home based business the most expensive lesson to be learnt here is to do nothing).