The Mighty Morphin Tower Arrangers are:

Chris Barlow

Darren Lewis

& Ted the Robot

About Us

The Mighty Morphin Tower Arrangers are a team entering into the competition, Eurobot 2009: Temples of Atlantis (see www.eurobot.org for details).

Darren Lewis and Chris Barlow are both BSc Engineering Product Design students from Middlesex University in North London, UK.

Although the task for this year's competition is a complex one, the Tower Arrangers' philosophy is to use as few moving parts as possible, and to use natural forces wherever they are available. This should result in an economical, reliable system designed to score a realistic number of points match after match.

This site will follow the team's progress from initial design to final build and our progress through the competition itself.

The Contest

"Eurobot is an amateur robotics contest open to groups of young people from around the world, organised in teams."

"The aims of the contest are to favour the public interest in robotics and encourage hands-on practice of science by young people. Eurobot is intended to take place in a friendly and sporting spirit."

"More than a simple championship for young people or a competition, Eurobot is a friendly opportunity to unleash technical imagination and exchange ideas, know-how, hints and
engineering knowledge around a common challenge. Creativity and interdisciplinary is necessary. Eurobot values fair play, solidarity, creativity and sharing of technical knowledge,
whether it is across technical realisations or project management."

"Eurobot takes place in Europe, but is open to teams from other continents. Countries with more than three teams interested in participating must organise a national qualification in order to select the three teams which will participate to Eurobot finals."

[www.eurobot.org, 2008-2009]

Friday 1 May 2009

42 Points!!

Footage from the UK Finals on 05/01/09 of the robot achieving its maximum score of 42 points.






Monday 27 April 2009

Claw & Software Revisions

As the day of the UK final approaches, focus has been put on getting the system as efficient as possible. During the rebuild, the claw was modified, bringing the lower support section closer to the bottom in the hope that it would support the lower part of the column better. This didn't work as planned. It turned out that this design made the tube too stiff, so it didn't flex in the right places. This put the claw's pressure on the higher discs, meaning that it wouldn't collect more than 2 or 3 discs at a time.

The design has now been reverted back to the original, with the support claws higher up, and a rubber band pulling the bottom of the claw into a funnel shape to support the column where it needs it most.



Also today, the team has started making changes to the program, to make the stacking process more efficient. The plan is to stay closer to the stacking zone during construction, so that less time is wasted during transit.

Friday 24 April 2009

Obstacle Avoidance

The team are using 2 Sharp infra-red sensors to find the position of other robots on the table. Both sensors are placed just higher than the column element dispensers to try to avoid the robot reacting to anything other than another robot. Both sensors face forward.

The team calibrated the sensors and created a sub program on the main drive board to tell the motors to react. When the sensors see another robot which is positioned in the way, the motors will stop for 0.7seconds, then if the sensors still see the robot, the motors will reverse until the other robot is gone, then attempt to return to the point it left.


Thursday 23 April 2009

Rebuild








During the second and third weeks of the Easter break (13th to 22nd April), the team rebuilt the entire robot with new parts. (Before to the left and after photos are below).

The laser cut MDF which provides the different levels was painted off-white.

The MDF parts that make up the claw were remade in white, opal acrylic; this reduced the friction on the guide rails.

The lintel mechanism was remade in laser cut white acrylic for strength and accuracy.

The PTFE casters were redesigned to be more adjustable; so as they ware down they can be moved, allowing the back of the robot to maintain the same height.

Poor quality micro switches were replaced with industrial standard switches.

The tapered shape at the front is widened allowing more room for error when collecting column elements.

Last but not least, the guide rails, track and vertical encoder was extended. This now gives the claw a 50mm higher lift. The team plan to use this to place 2 extra column elements on top of their original tower. This will raise the total points per match from 29 to 42.

Last few jobs are
- The pull cord
- Obstacle avoidance
- 90 second shut down timer
- Fine tuning all programs

Wednesday 1 April 2009

Further devolopment with temple construction

This video shows the robot building a temple when there is already a temple of the opposing colour in the same position that it wants to build. Also the robot collects 4 discs in the first row so it doesn't bother to drive around the rest of the grid, it goes straight to the stacking point.

Wednesday 25 March 2009

Lift Mech Improvements

The program has been modified to speed up the disc collection process. This means that the robot spends less time stopping for discs, and so will allow us to arrive at the construction zone earlier.

Saturday 21 March 2009

New Sponsors

Also this week, after a few weeks in planning, we can officially welcome our sponsors, Phoenix Dynamics.

"Established in 1994, Phoenix Dynamics is a leading supplier of interconnection solutions to the Defence, Automotive, Rail, Nuclear and Control System Industries."

Check out the website, www.phoenixdynamics.com for more information on the company.

Problem solved!

We finally fixed the intermittent problem with the odometry system. It seems that the fluctuations in the encoder readings were somehow caused by the latest version of the PicAxe software. We didn't see the fluctuations during the bench test on Thursday night because we were using a different laptop with the older version of the software!

The team is realising now how much time even the simplest change like that can set you back. The only reason we changed the software was because of the problem with the 'new' chips not working, but this week has emphasised how wise the words are: "If it aint broke, don't fix it!"

It's been a very trying week this week, particularly after the huge progress last week. It's such a relief to see it working again, we can now carry on developing the obstacle avoidance system, and doing some odd jobs making the robot look more presentable for the competition.

Friday 20 March 2009

Strange day

Despite thinking we'd solved the problem with the drive system, the robot was still doing different things on the table yesterday. We only have access to the practice table until 4.30 on a thursday, and went home at this time to carry out some tests.

We ran the sertexd command again to read the encoder values, and there are NO fluctuations in the readings what so ever now! However, we examined the last readings taken when the robot has finished each routine, and they vary considerably from the trigger values that we use to leave the subroutines. The largest deviation is 23 encoder counts, which is 1/3 of a wheel rotation! It's becoming a little clearer now what's causeing the variations in performance. The program is running too slowly to keep up with the readings from the encoders.

The options now are:

Try and speed up the program;
Use a larger, faster microcontroller for the main board;
Or, use slower reading, but less accurate encoders.

Today we need to make a decision on which route to take, and stick to it, as we don't have much time until the UK finals on May 1.

Thursday 19 March 2009

Problems, problems, problems

The last 5 days have been quite trying for the MMTA team. The on Friday, the bot developed a strange symptom that we still can't properly explain.

Firstly, during testing, every now and then the robot would start skipping a routine in its program. Carrying out a 'hard reset' on the Picaxe 28 main board seemed to temporarily solve this, and we put it down to 2 things: either noise from the DC motor driving the vertical lift, or an old, tired 28x1 chip. Noise suppression capacitors were fitted to the motor, and we atempted to change a chip over on the PicAxe 28 main board.

This was when the first major problem reared its head. Fitting any 28x1 chip other than the old one meant the robot refused to move! We eliminated all hardware problems, trying a spare board, about 5 or 6 spare chips, download cable and even a different laptop to put download the program! All to no avail! Eventually, the problem was traced to the communication between the board that operates the vertical lift and the main board. As the robot is traveling around the table, the board for the vertical lift is monitoring for when a disc passes beneath a downward-facing IR sensor. When it sees a disc, it waits for the disc to pass past the sensor and then tells the main board to stop the motors while the claw picks up the disc.

It was this communication that was broken, so the program on the main board jumped into the routine that stopped the motors straight away, hence it not moving. This problem was, eventually traced to the fact that the two boards are on different circuits, a pull-up resistor was fitted in the line, and it now works fine. Why this worked with the old chip, we aren't entirely sure. Perhaps the old chip was faulty in some way that conveniently made it work, or perhaps there has been a slight change in design in the internals for that particular chip. (if anyone has any suggestions, please leave a comment!).

Once we had it moving again things still weren't right. The robot was very rarely following the routines it was supposed to and would randomly spin on the spot, drive for too far, and generally mess up. By running a 'sertxd' command on the main board we were able to monitor the readings that we were getting from the encoders. We found that there were random fluctuations in the readings, where they would increase to over 65000, before returning to normal. An extra algorithm was added to the program to ignore these, but they were so frequent that it meant the robot would still not behave correctly. Eventually, yesterday, by eliminating everything else that we could have changed, we discovered that it was the noise suppression capacitors we fitted on friday that were actually generating noise and interfering with the communications between the main board and motor driver. Removing these capacitors, there are still the odd fluctuation, but nowhere near as bad as they were before.

We will look into other forms of sheilding to try and get rid of these, but for now, the robot is performing consistent enough to get it scoring points again.

Wednesday 11 March 2009

First Temple!

The robot successfully builds its first temple on the centre stacking point. This will achieve 29 points during a Eurobot match! The program still needs some work speeding up the timing and accuracy. As it stands, the program will successfully build the same temple for 4 out of the 10 random disc arrangements.

Monday 2 March 2009

Stacking Program Test

The first successful test of the stacking program was conducted on the playing table. The robot splits the 4 pre-collected column elements into 2 towers. Note the new rubber-lined plastic tube gripper, and the rubber wheel covers (made from balloons!) for extra grip on the table. These are far from being a long-term solution.

Thursday 19 February 2009

First Disc Collection

A down-facing IR sensor is used to detect the column elements on the floor. As the bot passes over them, it stops and picks them up, arranging them in a stack of four.


Friday 6 February 2009

Lift Claw Test with Column Elements

Column lift claw was tested using blind timing and a simple home-made circular encoder mounted on the drive pulley. A microswitch mounted at the top of the lift's travel provides a reset point for the encoders.


Sunday 25 January 2009

First Test of Lift Mechanism

Feasibility test for the lift mechanism was a huge success. A beer can of convenient mass and size was used to represent a group of 4 column elements. The 'Easy Roller' motor and Solarbotics track lift the mass easily and the sprung cardboard claw shows no signs of letting go of the beer!


Friday 16 January 2009

First Drive Platform Prototype

The first rough prototype of the drive platform was built and programmed to follow a path over the column element grid. A system was devised to compensate for inaccuracies in the odometry to ensure the discs were always in the correct position for picking up.