Robot Army

My sumo army is slowly growing… I ran out of wheels so one of them is still in pieces. Poor little robot…. it just wants to fight!

I’ll have these at the O.R.E. meeting tonight (May 9, 2011) for any one wanting to adopt a robot.

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SumoORE production underway

SumoORE production line is running at full capacity. ;-). Cutting chassis for these guys this afternoon and then I’ll have plenty for the time being.


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Sumo software libraries available

The first cut of the SumoORE software libraries and demo code is now available for download from the O.R.E. wiki webpages here:

The major functions and features of the software library is detailed there also, as well as a download link for the USB bootloader that we are using.

The main SumoORE platform is also discussed on the wiki pages here:

The first of hopefully many robots made it out into the wild yesterday! I’ll have 2 or 3 at the Monday O.R.E. meeting for $45 for anyone interested in getting a jump start on their minisumo.

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First steps with the sumoORE platform

Well, the sumoORE robot is coming along nicely. I’ve got all the software libraries essentially in place now so I wrote a quick little bit of code to demo a simple mini sumo. It checks the line sensors first. If a white line is detected, it reverses and turns away a random amount. If it is on black, it checks the two front sensors and tries to turn towards anything if it is seeing a strong reflection.

I’ve got a bit of code that turns the received IR signal into a rough estimate of distance to an object. I say rough, because the returned signal really depends on what it is seeing… large white objects reflect more light than small black objects. Still, it works well for the small sumo arena. It is sensitive enough that it sees objects outside the ring easily, so you have to keep back when you are running tests. 😉 If you look carefully in the video, you’ll see red leds lighting up on the two front corners and the rear when it is detecting IR.

No enemy detected gives a value of 0 from the IR detection routine. A strong signal being detected gives back a 76 or so (ie- all IR pulses sent out are received back). Everything else sits somewhere in between. For the demo code, I’m using a value of 70 and above as a detection. It means that the robot isn’t very aggressive but it doesn’t chase after ghosts outside the ring.

The robot also doesn’t check for the enemy when it is turning away from the edge. That is the first thing that someone using this robot will need to remedy. In the video you can see points where the robot should have gone after the block but ended up turning right past it.

Beyond that, the weight needs to come up. Its sitting right around 250 grams right now, so who ever takes one of these robots will have to start adding another 200+ grams of weight, both on the front blade as well as around the wheels. A thin strip of metal also needs to be added to the front blade to give a nice sharp edge to get under competitor. A thin piece of aluminum or brass will do the trick.

Anyhow, looks like it is going to be a really nice base to build on top of! Now I’ve just got to get started with populating more of the PCBs!

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CNRG/ORE Robot games website is live!

The Ottawa Robotics Enthusiast (O.R.E) group will be hosting a Canadian National Robot Games Regional competition on June 11th, 2011, in the Arts Court “Library”. The competition will be held at Arts Court, starting at 10am until 4pm. The event is open to the public and everyone is encouraged to either compete or come and check it all out.

We finally got the official website up and running here : Canadian National Robot Games website.

We’ve also got info up on the O.R.E. wiki, including details of some of the robots that are being put together to kick start the event as well as all the rules of the 4 different competitions.

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Back to the SumoORE chassis

Made some updates to the SumoORE chassis today. I moved the front blade out flush at the front, shaved a bit off the back, cut some openings at the back for the rear IR. Instead of black like the first chassis, I decided to make it from blue this time.

I’m using a 2mm bit and running at around 15ipm. I hold the sintra down with carpet tape and it works pretty well. If I cut too hard on the sintra though, it tends to lift a bit sometimes so I cut slow and steady instead… 2 passes. The machine is a Taig with Xylotex drivers and 269oz-in steppers. Nothing fancy, but gets the job done.












Final pieces.


And just in case you aren’t sick of look at my cutting the panels, here is a quick video showing the cut in progress :

After test fitting the new chassis, realized I still had some tweaks to do. The back was still slightly hitting when the robot was tilted backwards, the front IR slots in the blade weren’t large enough and the back IR opening was too big. I also needed to add mounting holes for the PCB and the cable that runs down to the ground sensors.

Just to keep it interesting, I cut a new chassis in red instead of blue.




Starting to assemble the chassis. Fits nice and snug.



With the top on, the chassis is nice and stiff. I’ll be using double-sided sticky tape between the ends of the servos at some point, but not just yet.


The PCB bolts right on. I love it when a plan comes together!


A quick pick showing how the batteries will mount, as well as the ground sensor PCB mounting. You can see in this pic that the back plate needs to be shortened up a wee bit still. I guess there will be a 4th rev of some of the panels.


Ready to run! Well… except for I haven’t soldered the battery pack together or shortened the servo cables so they fit in there.







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Working on sumoORE pcbs

Received the sumoORE pcbs from Seeedstudio finally so I’m working on building up a test platform with PCB and base. Assembly of the pcbs went pretty good. Lots of wide open space on these guys.





Schematics and details can be found here :


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2011 Firefighting competition at Trinity College

Me and a couple of other O.R.E. members spent the weekend in Hartford, Connecticut at the Trinity Firefighting Competition. It was my 8th year attending. Wow, time flies. As always, it was a blast. There is some sort of geek pheromone that permeates the air in the gym down there and always gets me geared up for building robots!

I’m terrible at remembering to take pictures, but I managed to grab a few interesting ones.

Below is a nicely built walking robot. Looks can be deceiving though… they didn’t do very well in the end.


This team from Indonesia on the other hand was unstoppable. They virtually dominated the robowaiter division, taking first in the Advanced and both 2 and 3rd in the regular division. They also took first and second in the walking firefighter division, as well as first and second in the senior firefighting division. Wow!


The red walker had some nice ball joints on the ends of the legs with small feet that could pivot and had some silicone(?) on the bottom for grip. Looked like it would give the robot a decent amount of stability even on less than optimal floor.


This next robot is more of the normal robot that you see at the competition. Masses of wiring everywhere. I don’t know how this robot did, but as the results from each year show, many robots fail to find a single candle. How many of those failed runs are due to a single wire getting pulled out while walking from their table to the area? 😉 Too many, I bet.


The Chinese team has been coming with the fastest robots for the last few years. Many of them are built on a common base from Grandar. The ones this year were largely built on the xPartner MF2001 base. It is a pretty nice little 4 wheel drive platform and really hauls butt. One problem that many of them have is getting 3 consistent runs in a row. It looks like much of the behaviour in the robots is largely preprogrammed and if anything goes wrong, the robot bounces around the maze like a pingpong ball in a wind storm. When everything goes right though, these things look incredible. I’m still trying to figure out how to get my hands on those red flame sensors that they use.


Here is a shot from the stands just before the opening ceremonies for the Robowaiter competition on Saturday. At the lower left you can see the standard division robotwaiter arena. The advanced arena has a fridge that needs to be opened and is a bit tougher. Only 1 robot was able to complete the advanced arena this year.


Another shot of the Indonesian robot that won the advanced robotwaiter. The entire plate grabber arm was mounted on a mechanism that could move back and forth independently from the rest of the robot. That meant that they could drive the robot up against the fridge and be out by a few inches one way or the other, and then position the arm exactly at the plate. Much easier to position an arm than to put the robot in the right position to start. Very slick. You can see the two halves of the plate grabber… looks like the shell of a ladybug or something. They formed it out of something along the lines of a melted pop bottle. Covering the whole thing when carrying the plate meant that they could move faster without having to worry about spilling the food. Nice!


Here we have a shot of the pits. There is always lots of last minute building. 😉


Here is a photo of one of the Indonesian firefighter robots. They were using water to put out the flames from what I could tell (two jets coming from the left and right) and then using the fan mounted a little further back to give the water spray a little turbulence and ensure the candle went out. I didn’t get to see these guys run, but it must have worked well given their final standings in the senior division!


A closer pic of their walker. This thing looked really cool when it was moving. Quite fast too.


Firefighting competition underway on Sunday. About half-way through at this point I believe.


And finally a few pictures of the Expert division firefighting arena. Instead of a single flame, this arena can have multiple flames, both in rooms as well as the hallways. It also has some incredibly hard-to-detect obstacles. This was the first year of this arena and it looked tough. There were 3 robots entered and none of them made it very far unfortunately. Lots of room for improvement next year!






Posted in Firefighting, Robot, Trinity College | 4 Comments

Line Maze Solver

Playing with turning my line follower into a maze solver for the robot games in Ottawa. Took a little video of it running a maze.

Its all pretty basic right now… just following the ‘left wall’ algorithm… takes every left turn it can. I haven’t added the code to solve the maze yet. Its basically a case of keep track of the dead ends and making the correct decision at the last intersection based on those dead ends I think.

Its a decent start I think, at least for a proof of concept. The maze rules for the games can be found here :

Posted in Line Following, LineORE, Maze Solving, Robot | 3 Comments

Moxie M38-360 continuous servo for minisumo

Received my Moxie continuous servos from last night and took a quick look at them. Pretty decent little things for $3.40! Metal bushing on the output shaft, decently fast and reasonably torquey. Construction inside was not too bad… no solder blobs bouncing around to short things out (can be a problem with some of the cheaper servos). I ran them head-to-head against the Parallax continuous servo and they are very slightly faster and have a little bit more torque so I’m happy with them. The pot for tuning center position with a 1500us servo pulse is actually nicer than the Parallax and easier to get set. The Parallax servos can be a little twitchy. Remains to be seen how durable they are.






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