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Thursday, 21 April 2016 11:38

Easter Camp

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Just finished our Easter Test Pilot again and had a terrific time.  We had an Easter event last year but this time around we wanted to run a really small event just to try out our new courses for 2016.  We figured this would both give us an incentive to develop the courses in a more detailed manner longer before the summer and also to be able to use the feedback of the campers to improve things for when we’re inundated with hundreds of campers in a few months’ time.

It was a great success – not only did we manage to iron out some minor wrinkles with the courses but the campers had a great time as well and to them it didn’t seem very different from a  ‘normal’ Tech Camp.

We were testing out four new courses – Quadcopters, Junior and Senior Robotics and our new version of Laser Tag.

Although we’ve previously run a quadcopter course last year, Harry (our quadcopter expert reading Robotics at Reading University) has put in quite a few new additions to the course this time, concentrating on giving the campers increased flying time to perfect their skills, exploring some of the more fun mathematics behind them (yes, Maths can be fun!), and trying out a series of new piloting challenges.  One of these was a ‘water balloon drop’ with the campers designing a release mechanism for this unusual cargo!  The Maths behind the quadcopters is a great example of where a seemingly dry topic can be terrifically engaging when applied to something like a quadcopter.  Quadcopters use a really intriguing algorithm called PID control which is used widely in real-world engineering tasks.  Essentially it uses some simple Maths to keep the quadcopter stable and level in flight.  The idea is that the machine has a series of sensors called accelerometers that detect any variation in movement.  The algorithm then works out an error value – essentially a difference between what the quadcopter is doing and what it should be doing and then works out the Proportional, Integral, and Differentiated components of this (hence the ‘PID’) to decide what it should be doing.  For those stretching their brains to remember what these are, the idea is that the ‘proportional’ component just multiplies the error by some constant – meaning that the further the device is from where it should be, the bigger the created correction signal is.  Integration is really just a process of summing, so adding an integral component compensates for build-up of error over time.  Differentiation is just measuring how quickly something is changing, so the differential component corrects the flight if the error starts changing rapidly.  By modifying these three constants you can make even complex control systems like the one built into the quadcopters behave nicely for the pilot and be much more easy to control.

The Senior Robotics course involved building a ‘Mearm’ – a 4 axis servo-controlled robot arm with an Arduino-compatible embedded microcontroller.  This course was designed by Jack, our long-time Tech Camp tutor and Cambridge engineer.  This campers had fun both building and programming their robot arm to perform repetitive tasks, move objects around and even draw pictures and text.  This course also use some fascinating Maths called ‘Inverse Kinematics’ to work out the position of the joints to move to a particular point or in a particular motion.  If you imagine your own arm it has several joints at the shoulder, elbow and wrist (and fingers as well).  If you want to position your hand at a specific point in 3D space you have to move each joint to a suitable location, but actually the joints are interlinked so moving any particular joint will move all three axes.  If this sounds confusing try to point to something with your finger and keep the end of the finger still whilst moving any one of these three joints – you’ll find that you need to move more than one joint at a time and actually there are an endless array of positions of these joints that will still allow your finger to point in the same position.  Try wiggling your elbow around as much as you can whilst keeping your finger in the same place and you’ll see what we mean!

Anyway, it’s all a great example of how something educational can be really fun, at least for those who have a curious mind, and we’re yet to find a Tech Camper who doesn’t.  After building their robots, learning about the Maths and Physics behind them, and learning a lot of coding skills in the process, the campers ended by hacking their arms to include an infrared receiver and then writing a programme to allow their robot arm to be remote-controlled.

The Junior Robotics course was equally fun but uses a simpler but still quite advanced robot called a Mirobot.  Rosemary, just graduating now as an engineer from Imperial ran this one for us.  It’s a really nice WiFi-controllable robot with accurate motors.  Rather than using conventional ‘DC motors’ this robot uses ‘stepper motors’ which take little electronic pulses to move the wheels precise amounts.  This means that you can get much more accurate motion and tell the robot to ‘Move 10.3cm’ rather than just ‘Move for one second’.  When coupled with a servo to control a pen, you then have a really nice drawing robot (think old-school ‘Logo’ and ‘Turtles’ for those that can remember that far back!).  Again this gives us a great excuse to slip in some Maths – particularly angles, geometry and some simple trigonometry as well.  We use a language similar to Scratch for the junior campers but for the hard-core enthusiast this nice little robot can even be programmed in Java.  Like all of our courses we always try to base them around take-home projects that are highly extensible so the fun and learning continues long after the event.

Finally, our Advanced Laser Tag campers built two of the new Laser Tag units.  They’re a huge step-up in technology from our previous kits, and incorporate an LCD screen, buttons, and even a WiFi module so that the game play can be controlled from a phone app.  This course was headed up by Felix (engineer at Imperial) and Mark (Comp Sci at Southampton) and ably assisted by Harry who only whilst only just exploring options himself for engineering at university has already helped several times with previous versions of Laser Tag, so he's well versed in good soldering technique (and fixing bad soldering!).

The campers designed their own style of laser guns, carved them out of high-density modelling foam, assembled some pretty tricky bits of electronics and then finally assembled everything together to indulge in some fun game play.  This was probably our most challenging ‘build’ ever at camp but the campers did a great job and everyone finished their units by the last morning which was perfect timing.  We might make one or two tweaks for the summer.  Although the 3D modelling was fun we’ll probably remove this and replace with some 2D CAD work to save some time.  This will allow us to explore more in the way of programming to allow the campers much more of an insight into the internal workings of both the hardware and software.  Hopefully this will also free up some time to do the painting of the laser taggers at camp rather than having to do this at home later.

Anyway, signing off for now – we’ll be busy for the next couple of months updating instructions, ordering parts, stocktaking tens of thousands of components and generally preparing for the summer madness – wish us luck!