Publication List Update

In the course of getting a job done, we all end up doing a bit of research. Here are some of the projects I’ve contributed to, from artificial intelligence to aircraft design, tissue simulation, human-machine interfaces and Lego Mindstorms! Feel free to check it out. Wherever possible, I’ve added the presentation versions, which are a bit more visual and a lot less text!

Don’t call it hydraulics

Disney has an big interest in animatronics – just try visiting one of their parks and avoiding it.

These are mainly kept at a very safe distance because either the visitor or the animatronic ‘robot’ are fragile compared to one another. Disney is all about interaction and asked the question – how can the animatronics and the visitors be safe around eachother? Disney Research Pittsburgh approached an old solution in a novel way – by removing some of the most problematic areas of working-fluid actuators in order to make a ‘softer’, friendlier animatronic.

The solution looks at first glance to be hydraulic – pressure lines connect pistons, allowing the actuator drive and the actuation posit to be separated. The system can work with an incompressible or compressible fluid.

The key difference over hydraulics is actually the lower performance – the lower working fluid pressure (100psi) and a unique ‘rolling gasket’ type seal in the pistons. This gasket reduces the problem of ‘sticktion’ (initial extra friction at the start of an actuation movement) to almost nothing, and reduces friction during travel as well. This requires less overall pressurization in the system to achieve smooth motion, and by moving the actuator motors off the robot itself, total mass is reduced, creating a positive feedback where less mass requires less actuation power. There are some design challenges that seem open, though: Continue reading

Minimum component infrared Camera trigger timelapse on canon cameras using Arduino

Check out "How Vacuum Tubes Work" to appreciate the convenience you get in your Arduino board.

Check out “How Vacuum Tubes Work” to appreciate the convenience you get in your Arduino board.


EOS M is a great little camera, but only has the Canon IR trigger for interval and timelapse. Here is a link to an Arduino sketch that outputs IR trigger signals on pins 12, 11, and 10 at 5, 15, and 30 seconds respectively. Designed to run on an Uno board with minimum external components – just change the IR LED + pin to the appropriate pin above for the timing you want. Credits in the code header. Let me know if you have any improvements!

.ino file

Technical Training….Training

“People aren’t puzzle pieces, turn-key products, or canned beans. They are investments, copilots, and will form connections within and outside your organization you never would have guessed”

Fuelling People is probably one of the tougher things to do in an organization – training programs, interesting work, mentorship, matched teams, surveys, open door policies, carefully tailored workloads are all a nice set of sliders and controls an organization can play with and optimize, But the most difficult thing is still creating training around an institutional knowledge set that includes some really hard-to-capture aspects – gut feel, interpersonal relations, estimating workloads and performance, turning measurements into decisions, and understanding people’s true capacities and capabilities.

Smashing has an interesting take on setting up technical courses for technical people inside a technical organization. A few key points, which I’ll add a bit to:

  • Give context and purpose to what you are teaching. The big picture – how will you be stronger within the organization, and how will it make the organization stronger (i.e. a better place to be!)
  • Teach by example. For example, the ‘Cookbook style’ Where a specific need is solved, allowing the learner to auto-generalize (something humans are almost too good at). Check out the micro article on learning as foundations and differences
  • Have some awesome homework. Learning is, in the end, doing, and watching someone else cook doesn’t make you a chef. Make the homework rewarding, possibly collaborative, and flexible to meet the motivations and interests of the learner. It’s also a breeding ground for real questions and feedback, not the polite stuff or pile-ons you might get immediately after a presentation
  • Learn how the training went – get feedback and get it immediately as well as later on. You have to learn how to teach people, after all, and accurate feedback is more than one datapoint in time – The term, “Let it sink in”, and “experience is the best teacher” have a very good reason to exist!

 

 

Splitting Learning into Foundations and Differences

My favourite techniques in extending technical knowledge are a “Parallels” method and the “Hub Analogy” method.

Parallels Method: For example, if someone knows how to solve a particular problem in Java, map each step over to the target language – say Objective C, and line up the equivalent functionality. Then, differences are much more easily explained, as they stand out from this common basis. This method works great when laterally moving through equivalent topics.

Hub Analogy Method: I recently had the opportunity to do a presentation to new pilots on how airplanes land at an airport. The aviation terms and language really make no sense to a newcomer, especially in 5 minutes, so I started with the idea that landing at an airport is a lot like going through a Tim Horton’s Drivethru: you line up, follow the signs, make a radio call with your request, and keep yourself away from other traffic. This had the benefit of allowing us to ‘hang’ new ideas off this solid mental model which everyone could be familiar with. For example, you can call the Tim Horton’s person the ‘Tower’ and introduce the concept of ‘runway clearance’ as the equivalent of, ‘please drive up to the second window’. A familiar and flexible hub analogy allows better student recall by splitting new learning into Foundation and Connected Differences, i.e. Hub and Spokes. This method works best when introducing less familiar or totally unfamiliar topics. (It is most notoriously misused in science documentaries as the classic units of measure: “Human Hair”, “elephants”, “Golf Ball” and “Football Fields”)

No technique is going to work as well without examples. Popular books from Gladwell and Kahneman are completely saturated with examples because they know that we learn by generalizing, not by making up specifics after memorizing some abstract framework. Humans evolved to think, “I don’t eat that fish because that one time I did was pretty bad, therefore, no yellow-striped fish for me of any kind.”, not, “anything that is sending a signal it is poisonous is highly visible as opposed to camouflaged, therefore I will not try that fish over there.” Examples are also a form of storytelling – which is just a way of conveying a personal experience like, “In and Out: That One Time I Ate That Yellow Striped Yuck Fish”. We love stories because humans are empathy machines, and blur our Specifics into Generalizations.

 

 

 

Displays in a vibrating environment: How NASA addressed a blurry problem

vibratingDisplay2

The effect of synchronized strobed display to reduce motion blurring readibility issues in a high vibration environment. Or more specifically, Turning a mess into less of a mess.

The stereotypes are true: the boost into space from sea level is a shaky, G-infested carnival ride with every Fourier component you care to name. NASA had a similar problem as part of its problematic Ares 1 project. Some rockets have a dominant resonance frequency in long axis that is termed ‘pogo’ (like the stick) and in human rated vehicles this means a dominant mode vibration passes to the passengers. In the case of the Ares I, this was on the order of 0.7G’s at about 12 Hertz, working out to around 5mm motion. If the computer displays the passenger is looking at do not have the same damping and resonance characteristics as their own eyes and head, motion blur in the displays will make them unreadable as simulated above.

A solution tested was to strobe the display in the same way LED-based displays are dimmed – a square wave duty cycle is applied so that the display is actually off some of time. The duty cycle is synchronized to the main vibrational component of the the pogo motion, removing the worst of the motion blur at the expense of some brightness (This simulated view assumes that brightness can be boosted somewhat to compensate).

 

Trading Brightness for clarity: effect of strobing a display in sync with a sinusoidal vibration mode

Trading Brightness for clarity: effect of strobing a display in sync with a sinusoidal vibration mode

When compensating for a single, sinusoidal mode, the loss in brightness is not that great if the duty cycle of the strobing is phase matched to a displacement peak of the motion as shown. A vibration reduction of 90% is possible with a 20% duty cycle, or 80% loss in brightness.

Read the article and see the demo video here:

http://gizmodo.com/5880850/how-nasa-solved-a-100-million-problem-for-five-bucks