Micromouseonline Forum

by slurp (Posted Sun Jun 27, 2010 11:25 pm)
Hi,

I'm sure it was Jim (amongst others) that I was talking to about 3D modelling, it was CoCreate Personal Edition I was using for the "printed" wheels.

You can find that here:-

http://www.ptc.com/offers/tryout/pe2.htm

Best regards,
Colin

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by slurp (Posted Sun Jun 27, 2010 9:20 pm)
Thanks Tony,

Another fabulous event, I never find enough time to see everything. I hope to complete a short write-up on the minisumo shortly, with thanks to Mike I can add video for most rounds.... I jumped in quick on my only decisive win as he was changing batteries on his minisumo

I've got some interesting observations and I'm formulating a few mods for my minisumo

It was great to go head to head with all the other minisumo, everybody got at least one win. I'll post the full tally details with the write up later.

Mean time the Summary:-
[list=]
[*]Stealth 2 (PeterW) - 6
[*]Insumountable (PeterW) - 5
[*]Spykee (ChrisG) 4
[*]Lowblow (PeterW) - 3
[*]AFM (ColinD) - 3
[*]Stybb (Mike) - 2
[*]Intecepter (Rich) - 2
[*]Noname (Mike) - 1
[/list]

Thanks also to Matrix Multimedia for the kind donation of prize.

Best regards,
Colin

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by PeterW (Posted Sun Jun 27, 2010 4:21 pm)
Another great event thanks to Tony and all his helpers for all the hard work.
Also nice to see more of the school and other events such as minisumo and line followers starting to take off.

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by tony wilcox (Posted Thu Jun 24, 2010 10:15 pm)
Hi Colin

Thats sounds really good - I'll make sure you have an appropriate area. Please come see me if you are running a competition and we'll make sure we fit it in to the schedule so that all can watch.

Regards

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by slurp (Posted Thu Jun 24, 2010 7:49 pm)
I'm looking forward to the weekend, I think we'll see at least 6-8 minsumo

Best regards,
Colin

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by gbulmer (Posted Tue Jun 15, 2010 9:19 pm)
I thought folks be interested/amused by this robot challenge.
It is run every year by a Home Brew Robot Club in Silicon Valley.

The rules are delightfully simple:
"A TABLEBot is a robot that survives, lives and plays on a table... or pays the price.

Phase I: Build a robot that goes from one end of a table to the other and back.
Phase II: Have the robot push a block off the edge of the table.
Phase III: Have the robot push the block into a shoebox mounted at the end of the table.

June 2009 - Phase I
August 2009 - Phase II
October 2009 - Phase III"

There are also Pictures of entrants. Some are pretty funny looking (and probably work fine), and some very slick.

GB

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by gbulmer (Posted Mon Jun 14, 2010 10:53 pm)
Some of you folks may be interested in the upcoming "Vintage Computer Festival" on June 19th at Bletchley Park, where we invented the computer*, and built the first ones during WW2, to crack the Enigma codes.

Details at http://www.bletchleypark.org.uk/calendar/event_detail.rhtm?cat=special&recID=594620

* Yes, I know the USA claim they invented the computer, but the UK government is so secrative that they didn't file any patents, or even mention it for 40 or 50 years, just as they gave away our atomic weapon research for free, oh, and radar, penicilin, supersonic aircraft, rockets, ... And yes, we probably do deserve competent politicians, but there aren't any left in the packet.

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by tony wilcox (Posted Wed Jun 02, 2010 2:55 pm)
Hi anyone involved with the named beasts

- a reminder that you are all welcome at UK Micromouse 2010 on Saturday 26th June at Millennium Point.

www.tic.ac.uk/micromouse

As per previous years I will make space available for demonstrations or your own competitions.

If readers of this could please spread the word I would be grateful - the more we have at UKMM2010 the better.

Tony

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by tony wilcox (Posted Wed Jun 02, 2010 2:51 pm)
Hi everyone -

Could you please register if you intend to attend UKMM2010?

http://www.tic.ac.uk/micromouse/Registration2010.asp

If the registration form is too involved just send me an email with brief details - I need to know so I can plan the important things like pit space, coffee and biscuits!

tony.wilcox@bcu.ac.uk

Regards

Tony

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by peteh (Posted Fri May 14, 2010 7:19 pm)
The current drain seems to be the greatest issue. With many micro processors having timers and PWM units designed to generate three-phase drive signals, it seems to me that a brushless motor would otherwise be quite attractive. Opn-loop control of the commutation would make it a bit like using a stepper motor.

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by pittuck (Posted Thu May 13, 2010 9:57 pm)
Hello all,

Since I started working with proper DC motors (the type which make a noticable dent on the credit card statement) I have considered using brushless motors. Until today I have never spun one up without a model helicopter attached; initial results are 'pleasing' as in there is definitely enough torque even at a current draw of 0.5, so here are my pro's and con's as I see it now.

Pro's:
[list=]Unit cost ~$15
Run at 7.4V
Back-emf or Hall effect for position sensing - not expensive
[/list]

Con's:
[list=]RPM - upwards of 8k under a load drawing 3.5A (gearing issue, will need to be a long gear train, or very high 'single step' ratios whilst still retaining the ability to transfer the torque)
Circuit Complexity - Electronic Comutation is complex, and when u miss a step it goes very wrong very fast.
Cogging - Low speeds may be very hard as there is a cogging effect between the permenant magnets[/list]

The circuit complexity is not really that much of an issue as its an extra half bridge in effect, but with back emf and current sensing its probably going to be in the region of 50% to 100% more board space.

The RPM and Cogging are fiarly intermixed, if you can get the really high ratios then the cogging starts to go away as to get slow velocity you still require a decent amount of RPM.

The biggest problem, which is not mentioned above, is the software. With a DC motor you can plug it into a controller and allow the controller to quickly put the volts all over the place to achieve the required response, I know that quite often my controller will put a 'reverse' voltage across the motor to stop it. Thats all well and good with that system, however there is a question over the ability to handle such controller requests on the software comutation and maintain a 'linear' (or even easily predicatable) behaviour.

Anyhow, thoughts/comments/experiences welcome!

The motor: http://www.himodel.com/electric/9g_2200KV_Outrunner_Brushless_Motor_Type_A1504.html

IMAG0006.jpg
You can just make out the motor dangling off the wire strippers at the bottom. A proper motor holder being built atm, and now that I have proved it works in principle I will put together a test circuit driver circuit capable of driving around 5A with the dsPIC on the explorer16 development board (in the background) driving it.

Currently I am using a off the shelf RC motor driver for testing (I have some uber motors to play with too :D)

Thanks,

Martyn

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by kingisme (Posted Thu May 13, 2010 5:34 am)
Hi, i downloaded a normal Maze Solving Program from Matrix Multimedia:formula flowcode. And i need to edit and change it to a program that memories the maze itself anyone can teach me? or give some examples for me? im using the Flowcode V4 for PICmicros.

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by tam85 (Posted Wed May 12, 2010 7:48 am)
using two flanged ball-bearings in your wheel hub assembly can handle high shaft velocities that gives excellent performance.

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by pjramsay (Posted Tue May 11, 2010 1:04 pm)
Hello fellow roboticists!
My name is Peter and I am a 22 year old studying a BSC Robotics degree at Bristol UWE (University of the West of England). If I pass my exams this year, which I am currently undertaking, I shall be starting a rather substantial micromouse project this summer to be completed by a similar time next year.

I can program in C to an intermediate level, I can cope with electronics and digital systems and design, have been introduced AI and have of course studied Robotics in general. I figured joining this forum would give me an invaluable source of information concerning the particular practice of mircomouse engineering and an oppurtunity to share and learn many new things concerning my degree.

What I have accomplished so far:

We have only made a couple of basic robots in the past and mainly using the Lego Mindstorms kit and a programmable board called an Arduino. First was a hexapod which was purely reactive, so crossed a 2m stretch in minimal time then stopped before colliding with the wall. Next was a deliberative design which followed a line, avoided an obstacle blocking the line, finding the line again then stopping at the end of the line, at the end giving a measurement of distance travelled. This had to be done using some self-made sensors such as coupled LEDs and LDRs and some sensors supplied like SRF (sharp range finder) and ultrasonic.

For our programming in C module produced a C source file that would demonstrate the use of an AI subsumption architecture with various tasks to control a robotics buggy: follow a line, follow light, retrace path and joystick control.

In Practical Electronics we had two major products one to produce an audio amplifier circuit, to be soldered on to a PCB and a battery powered 6xwhite LED torch using a boost converter. In digital design we used PICs in assembler and some C and PLDs (programmable logic devices) and have studied logic and AC waveforms in a lot of depth. Anyway I think thats it!

Thanks,
Peter

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by peteh (Posted Tue May 11, 2010 6:49 am)
Probably the easiest way is to use forward looking sensors to detect the corners and steer away from them. this works very well if you can make sure your mouse is nicely aligned at the start of the diagonal.

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by lekhoa88 (Posted Tue May 11, 2010 1:21 am)
I'm currently working on the running diagonally. Can someone give me a pointer on how would I use the sensor to make sure that the mouse doesn't crash into the wall?
Is it possible to have the mouse run diagonally with 90 degree side sensors

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by kingisme (Posted Mon May 10, 2010 11:58 am)
any one knows how to use C program in a flowchart? im using flowcode V3 demo version... but i can only do limited stuff using that... does anyone knows how to use C program in the flowchart?

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by kingisme (Posted Mon May 10, 2010 5:09 am)
I need help in our micro mouse programming... I have a micro mouse by formula flowcode, matrix multimedia. But i only have the demo version flowcode V3 of the programming... so i want to use C programming rather than the flowchart program to make the micro mouse move... but i don't know how... Can anyone teach me here?

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by loricohen87 (Posted Mon May 10, 2010 4:44 am)
Loads of bad dissertations have been written and yet there are many to be written. It seems some students set up their minds while writing a dissertation to come up with the worst dissertation ever been written. The great dissertations are so rare that dissertation of a bad quality overtakes the high quality dissertation in huge numbers.

Do you want to know how students help themselves to write bad dissertations?

Here are some dissertation writing mistakes that help students to come up with the worst dissertation one of its own kind:

1. Surrounding themselves with in-agreement people: Doctoral students have a habit to surround themselves by like-minded people who think just like them. Although, this habit help themselves a lot in writing a dissertation but they become deprive of the views that may stand out their dissertation as a challenge to be accepted among the better ones; ultimately, their dissertation writing seems ordinary.

2. Selecting the topic just for them: Many students convince themselves about the topic they choose without bearing in mind about recent periodicals or dissertations. Who knows the topic that appears fascinating to them become out dated?

3. Continuing with a broader scope and vague terms: Many students can’t kept their breadth in a broader scope of dissertation writing as they run after more than one ideas to finish their dissertation as early as possibly without considering about the consequences.

4. Holding back the creativity by ignoring the outline: An outline serves as a roadmap to dissertation but students are used to of ignoring the dissertation outline that they don’t even think to plan their dissertation writing.

5. Confining to restricted bibliography: It appears that students refer to bibliographies that support their point of view only. They ignore that the purpose of dissertation is to study a valuable question and not meant to prove your point of view.

6. Presuming that anything not written in English worth nothing! Students don’t even try to value the literature written in any language other than English that help themselves in writing an incomplete dissertation; hence their literature review remains a mystery.

7. Declaring statements by force and not by proof: Many students don’t even think to justify their statements regarding their dissertations on the basis of proof. They think that the way to make an impressive statement is to outcry the side of evidence.

8. Why to proofread and waste your time? At times, students prefer to cut out the proofread that prevent their dissertation writing to be free of weak arguments, ideas or spelling mistakes.

9. Why should the assistance of experts be taken? It’s a general observation that the students avoid to take assistance of experts about their dissertation topics so that they can get help from them regarding the aspects of their work.

10. Proving the point at all cost: Loads of students use fake methodologies, false evidence and forced arguments to prove their point at all cost whether it’s right or wrong that lead their dissertation to be rejected.

These were the common mistakes that doctoral students make most of the times. Are you one of them?

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