The Growing Potential Use of Unmanned Aerial Systems for Condition Monitoring

Unmanned aerial systems (UASs) combine a drone with a sensor payload and analytics to deliver a remote monitoring and diagnostic service. To date, UASs have been used primarily for collecting images over an area, often geo-rectified so that the images are accurately tied to a location on a digital map. Examples include agricultural crop quality, environmental monitoring of industrial facilities, and surveillance of possible encroachment or third-party activity on a site.

But there are many opportunities for a UAS beyond making visual observations from a distance, and some of these will be of great potential value to machinery condition monitoring and diagnostics.

Drones have become inexpensive and popular, due to economies of scale for small microcontrollers that allow rotorcraft drones and fixed wing drones to remain stable in flight without extensive operator training. Most such drones are small, and can only carry a small payload. Flight times are short, on the order of ten to twenty minutes, depending on mission profile and payload. Communication distances are also short. This is an advantage for safe operation, as there is less chance that the operator will lose situational awareness and crash the drone. Small drones flying slowly are much less of a hazard than large, fast drones; however, for a UAS to be a cost-effective method for condition monitoring of remote, distributed assets, the drone must be large enough to carry a reliable payload, withstand wind gusts, and have sufficient battery power or fuel for a reasonable mission duration, both for flying as well as powering payload and communications systems. Some types of measurements employ contact sensors, and so the UAS must be capable of deploying a sensor to bring it into contact with a surface before collecting data. Hybrid drones are coming to market, which are able to take off and land vertically on a charging station using rotors and then use wings for flying a route.

Along with technical issues with using a UAS, there are regulatory issues. A typical UAS is a remote-controlled drone that must remain within line-of-sight of the operator. Regulations in most jurisdictions prohibit flying over inhabited areas and close to airports and helicopter landing pads.

Despite these limitations, there are many opportunities for a UAS for machinery failure prevention, such as:

Vibration (contact, passive)

Ultrasonic structural integrity (contact, active)

Optical thermography & spectroscopy

Chemical analysis (noncontact)

Surface sampling (contact)

Environmental interactions

Photogrammetry (gauge reading)

A UAS can also be used to deploy permanent sensor packages, or to act as a communication network by flying past a sensor that delivers a burst of time-stamped data that the UAS archives and then delivers to a ground station for analysis.

Active areas of development include: sensor payloads, contact sensor deployment & connection management, autonomous hovering with gusts and contact dynamics, data collection & management, power management, and mission planning. None of these challenges entails basic research. The technical issues are mostly subsystem development and system integration.

More importantly, methods are needed to integrate UASs into regular inspection programs in such a way as to not add risk to the overall operation. Once demonstrated in controlled industrial situations, then a case can be made to regulators that a particular technology suite and mission can be safe. Transport Canada’s Special Flight Operating Certificate follows this principle. While beyond-line-of-sight operations are not yet generally possible in Canada, demonstration systems are already being tested in specific sparsely populated airspace with strict controls on potential risks to the public.

Given this combination of technology development and regulator engagement, it is likely that unmanned aerial systems will become a viable option for reducing the risk to inspectors and lowering costs of condition-based maintenance programs.


“Thetareddast” (We’ll Figure It Out)

Wow, week three at Reykjavik University. Time flies.

Iceland is wonderful.
(And sometimes rainy.)
(And sometimes cold.)
(And always expensive.)
But the people are terrific and the land is absolutely awe-inspiring.
The entrepreneurship course has excellent. I have been learning as well as teaching. Reykjavik University is a modern school, very well run, with enthusiastic and energetic faculty, staff, and students.
I have been living in a house with five students. It’s been a long time since I have had housemates! Fortunately, they are great young people and appear to be unaware of my foibles. Or at least they are too polite to mention them.
A common expression in Iceland is thetareddast, which roughly means “we’ll figure it out.” This is emblematic of an Icelandic attitude that probably arises from the changeable weather, which compels people to be flexible in planning their activities. It also makes people nimble in their thinking. Perfect for entrepreneurship.
Thanks to our thoughtful and generous hosts, I have had opportunities to visit innovation clusters and meet their leaders and the people developing their startups. The start-up ecosystem is very lively. Later this week I hope to visit a geothermal power plant.
I have also run beside the ocean, climbed a volcano, been sprayed by a geyser, and scuba dived in a glacier-fed lake with amazing geological structures at the junction of two tectonic plates.

On Friday the teams make their third and final pitch, and present their business plans and product design concepts. On Saturday, we return to Canada to plan our own version of this course, and to continue developing collaborations with Iceland. We’ll figure it out.

A Three-Week Introduction to Entrepreneurial Design

I am participating in an intensive three-week entrepreneurial design course at Reykjavik University, which all first-year students take. Students are assigned to multi-disciplinary teams, and are challenged to find a problem worth solving that could lead to a technically feasible, scalable design that could form the basis for a business. The organizers of the course have welcomed a dozen of us from U of A to observe, participate, and learn how this approach might be implemented at U of A.

We arrived yesterday morning after an overnight flight. Although jet-lagged, I was excited. I have wanted to visit Iceland ever since I read “Journey to the Centre of the Earth” by Jules Verne (which was a long time ago). Verne’s adventurers didn’t have to deal with buying new SIM cards for their phones. But I digress. Icelanders are welcoming and generally quite fluent in English, which makes traveling embarrassingly easy. We rented two residences for the duration of our stay, each an easy forty-minute walk to campus.

After provisioning (Verne’s adventurers didn’t have to deal with using Google translate to understand labels in the grocery store), we made a short excursion into the countryside to stay awake. The scenery was pristine and spectacular, easily living up to all of the hype. We stopped at Seljalandsfoss waterfall and walked behind the falls. Bracing. Okay, freezing. But amazing. The rainbow was almost too much.

The hosts at Reykjavik University have been gracious, well prepared, and welcoming. We were introduced to a number of university dignitaries, and then participated in the opening ceremony and introductory lectures. Then we got to work. U of A students were assigned to teams with Icelanders, while the U of A professors – Mario Nascimento, Tony Briggs, and I met with various student teams to help them brainstorm, and then met with Reykjavik U professors to discuss some aspects of the course.

So far, so good.

Better start working on my slides for my lecture next week…

Machinery Diagnostics in Beersheba

I have enjoyed my time in Beersheba. It is on the edge of the Negev desert. Koby Bortman and his students have been great to work with. I have had a nice little place to stay in, which has been good for keeping up with what is going on in Canada nine time zones away.  Writing papers is efficient when there are authors on two different shifts.

The machinery diagnostics lab here has a good approach to research in this area. Relationships between models and experimental results are based on simulations calibrated to the lab apparatus. This gives a good opportunity to assess the model quality against real data. Of course, the simulations don’t always work as hoped. I have spent a lot of time with students staring at graphs trying to figure out what the problem is. To troubleshoot a simulation, we can take several  steps:

1) check the solver
change time step and look at the sensitivity of the solution between different cases
change solver type (slower-order solver will be more robust but less accurate)
2) simplify the mathematical model
change the model to linearize it, or to remove some terms, so that the model is simpler (and hopefully the simulation results can be compared to a benchmark case or to an analytical solution). Another option is to change parameters of the model to make the set of equations less stiff (that is, less sensitive to small changes)
3) change the mathematical model
if some part of the model is causing the problem, then we may need to change the formulation, for example, making the nonlinear functions continuous.
In all cases, having a data set for verification is critical.
This is fun.

Masada, The Dead Sea, and Working Eight Time Zones Away

I have been in Beersheba, on the edge of the Negev Desert in Israel, for a couple of weeks. Other than the culture shock of not speaking Hebrew, it has been pretty good. People are generally friendly, although, um, assertive, and I have really enjoyed the collaborations that I have embarked upon at Ben Gurion University of the Negev.

Until now, I have been focused on working with students, and keeping up with work back in Canada. Being on the shift schedule before everyone in Alberta has its advantages. I am able to get a day’s worth of work done before the emails start rolling in. But it does mean the occasional Skype call with a student team at 11 pm.

I traveled East to the Dead Sea on the weekend with my host Jacob and his wife Dora. It was a splendid day. We went to Masada, the ruins of Herod’s fortress taken over by Zealots in 70 AD and then besieged by the Roman army. The fortifications are 400 m above the rift valley of the Dead Sea. The view (straight-down) from the palace lookout is exhilarating – and alarming. A quiet place for such a violent history.

The Dead Sea is, well, a saturated solution of salt water, with a bottom of salt grains. I tend to sink rather than float, but this time I could relax completely. Savasana in salt. The surroundings are stark, but people were relaxed, just enjoying the day.

I think I will try the Red Sea next.

Professor, Mechanical Engineering