Category The Challenges

The Challenges

Custom Printed Circuit Boards

One thing that has cropped up each year with our robot has been wiring issues. This comes about due to the modular nature of our bot.

We can swap modules based on the challenge we are doing. This has normally led to needing to swap wires around in a very cramped space.

This year the team have decided to replace as much of the wiering as possible with custom made Printed Circuit Boards (or PCB’s).

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The boards needed some of the components surface Mounted! Keith worked his magic and with the small components mounted we are ready to test them out!

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14th April 2018
Fun, The Challenges

Colour Detection using OpenCV

The below clip shows another example of our colour detection script running on the Raspberry Pi.

We have used C++ and Open CV to detect the colour at a certain position in the frame.

The colour is then show in the top left corner of the video.

This will also be shown on a tiny OLED screen on the body of the robot.

 

 

 

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8th February 2018
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models, The Challenges

Nerf and back again!

Since our robot base is staying much the same as last years, we have been working on modules that can be switched for each competition.
We need our robot to hold and fire Nerf Darts.

Our excellent team engineer has been working his magic with a 3d printer and a lot of patience to create us just what we need!

Above you can see the 3d rendering of our robot and mount. Below you can see a time-lapse of the mount being printed

This will allow us to hold a standard Nerf Dart Cartridge and fire the darts on command.

The finished mount!

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No comments 7th February 2018
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Fun, lessons, The Challenges

Somewhere Over the Rainbow – Colour Detection

One of this years challenges is to detect  some coloured balls from a distance and visit them.

The full details are here. http://piwars.org/2018-competition/challenges/somewhere-over-the-rainbow/

For our robot we are using a Raspberry Pi Camera and OpenCV to detect the colours and some code written in C++.

You can see a video of our robot doing some colour detection below.

Whilst testing this we have come unstuck with the detection when it is dark or when somebody (Vince) in a very red coat walks into the frame of the camera and it detects him and not the ball.

We are planning on using a 2 times lens to bring the balls into a better focus.

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No comments 3rd February 2018
Fun, The Challenges

Nerf Assembly – 3D Render

Keith has been working with a tool called “Fusion360” to create the 3d models for our robot. This can then create the 3d printing file as well as laser cutter instructions. However – one other feature is that it allows you to create an animation of the 3d object!

This video shows our Nerf mount!

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5th November 2017
Nerf Gun mounted to robot No comments
The Challenges

Nerf gun mount

Keith has been doing some more model work in Fusion360 (not on the cat walk!) So far he has the guts of the Nerf gun launch system and magazine modelled, and work has started on the mount system.  Over the next few weeks hopefully he will get this finished and we can get the parts cut and printed and trial fit them to the bot.

Nerf Gun mounted to robot

Nerf Gun mounted to robot

Nerf gun mount

Nerf gun mount, viewed from below

Nerf Gun mounted to robot

Nerf Gun mounted to robot

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No comments 1st November 2017
The Challenges

OpenCV object tracking

Last week Phil was playing around with object tracking.  So far he can identify colour objects and track the centre.  Phil produced a quick video showing how a red skittle (from last years PiWars skittles challenge) can be tracked and traced on screen.  This looks like a good start, now just need to get the robot to follow it.

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30th October 2017
Cheap power supply No comments
The Challenges

Power supply and motors

Keith has been playing about with a new cheap power supply using the Nerf Gun motors as a test bed.  It turns out power supplies are quite a good method for determining how much current they draw and thus what current the motor driver needs to deal with.  Keith produced a quick video demonstrating the power supply with examples using the Nerf Gun motors.

If you are still deciding on motor drivers he recommends getting the motors first and doing a simple stall test with a power supply or multimeter and then getting the motor driver to suit.

See his video here:

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No comments 28th October 2017
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The Challenges

The Duck Shoot

The first challenge the team want to tackle is “The Duck Shoot” as this is new to this years event. The challenge involves shooting five targets down over three attempts.

Since the rules allow Nerf darts to be used, Phil went out a procured a nice looking, powerful gun!

The Strip down!

The only bit we need of the gun however is the dart holder and the firing mechanism. So the team set to work stripping this down and designing a robot mount that means we can add and remove the challenge components as we go.

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The testing

One thing we need to be careful about, is power. If the device needs too much power we will need to change batteries too often, to little and we could miss the target. So to ensure that this is calculated, we need to test the power requirements.

In true maker spirit Keith brought a Bench power supply kit from eBay and tested the requirements of the Nerf motor

Bench testing the Gun

Motors pull 1.9A on spin up and then drop to 500mA. With my
New power supply I can limit to 600mA and it spins up nicely. I’ll have to see how I can do that in hardware to be kind to our Pi

So thew challenge here for us is to design a circuit to limit the power consumption of the motors.

Hopefully with the experts we have in the team, a nice tiny circuit will be designed that will help with the power.🤞

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No comments 15th October 2017

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