Micromouse Book

Posted Thu, 28/01/2010 - 23:49 by peteh

The micromouse book collects together all the information I found out while learning to build a competitive micromouse.

Finding all this out for yourself can be real hard work even with the power of the mighty Google to hand. So, to save some trouble and give newcomers a head start, I put it all together into some web pages. These were originally published on another site which will probably be gone by the time you get to read this.

All of that information is now gathered here in the form of a single 'book'. The navigation for that book should appear in one of the side bars.

 

Comments

Hate the new website

by Anonymous (not verified) - 06/02/2010 - 13:42
relevant information of competition is removed

Which bits are missing?

by peteh - 06/02/2010 - 18:44
Exactly what do you miss?

history of the compettion. I

by Anonymous (not verified) - 09/02/2010 - 18:03
history of the compettion. I used the website as a reference to my report. But the link brings me directly to this page.

OK - fair comment

by peteh - 09/02/2010 - 21:25
I have changed the redirection and added in the history page.

If your link points to

http://micromouse.cannock.ac.uk/history.htm

it will now get redirected straight to the replacement history page.

Let me know if that works for you.

Thank you so much. i

by Anonymous (not verified) - 18/02/2010 - 11:35
Thank you so much. i appreciate the instant response.

De Alberto

by Anonymous (not verified) - 08/04/2010 - 02:55
Nesecito controlar un motor de paso con PIC16f84 y el hardware sla7024 ya lo conecté completo y programé el pic revisé bien todo hasta el orden lógico de paso del motor pero no me funciona ; que debo hacer?

Has revisado la sla7024, en

by ismel (not verified) - 26/04/2010 - 17:44
Has revisado la sla7024, en el datasheet hay una configuracion de hardware, o sea , algunos componentes externos, este driver lo he provado con una FPGA y trabaja OK, enviame el esquema de tu aplicacion a mi correo y te dire mas.......

escribeme

by ismel (not verified) - 26/04/2010 - 17:50
enviame tu esquema a mi correo y te dire si es problema de hardware ismel@tele.upr.edu.cu

what is robate micro mouse?

by tahmin (not verified) - 05/05/2010 - 11:22
what is robate micro mouse?

This is my first time I have

by Thanh Hamaker (not verified) - 13/05/2010 - 01:24
This is my first time I have visited this site. I found a lot of interesting stuff in your blog. From the volume of comments on your articles, I guess I am not the only one! keep up the great work. paris sportif

micromouse

by Patrick (not verified) - 25/05/2010 - 10:00
hello there. I was wondering what was yur method of odometry for the decimus. and also , if i use a 1 axis yaw gyroscope sensor can i use it to tell the degree a mouse rotated?

Odometry

by peteh - 25/05/2010 - 15:44
Decimus uses encoders on the motors for odometry. These give about 24 pulses per millimeter of travel. Right now, Decimus does not use a Gyro. However, what you ask is perfectly possible. A Gyro would be used both to control the rate of turn and the angle of a turn.

is odometry extremely

by Patrick (not verified) - 26/05/2010 - 13:59
is odometry extremely important? if so i would be using the simple ir encoder form of odomerty and not have built in encoders. Would this pose a large problem?

i see that u have pretty high

by Patrick (not verified) - 26/05/2010 - 14:22
i see that u have pretty high resoltion. if i have wheel of 10 cm circumference and if i have ten segemnts meaning each pulse is 1 cm, will it pose a problem?

Improve the resolution

by peteh - 26/05/2010 - 18:05
I think you need to find a way to improve the resolution of your mouse. It really wants to be down to one or two millimeters if you can manage it. the technique I described for motion control is not going to work well or possibly at all with low resolution. Instead, I think you need to just turn on the motors only hard enough to prevent slipping. Once you have gone a few cm, turn them on a bit harder. To control speed with low resolution encoders, you may have to measure the amount of time between pulses rather than the number of pulses in a given time.

What would u recommned to

by Patrick (not verified) - 30/05/2010 - 08:34
What would u recommned to improve resolution? Getting Faulhaber motors seem to be a little out of my price since it is my first mouse.

some suggestions

by peteh - 30/05/2010 - 22:00
It is hard to recommend anything in particular without knowing what you have available or what your skills may be. However, three possibilities come to mind.
First, you can find an old computer mouse - the kind with an encoder wheel - and use that. Here is a picture of a mouse that does exactly that:
From UK Micromouse finals 2007
Second, you can try the Austria Microsystems AS5040 magnetic encoder. This can be used with a magnet attached to the motor shaft or the drivewheel shaft to give quite high resolution. Here is a mouse with one of these:
From UK Micromouse 2008

Third, you could print an encoder wheel on some OHP transparency and attach it to the motor shaft and use the same kind of optical encoders as are used in a mouse as described above. I don't have a picture of that but it can be made to work very well.

WOW! Thanks for the great

by Patrick (not verified) - 31/05/2010 - 15:47
WOW! Thanks for the great suggestions! I decided to follow the trackballs mouse method as it is the cheapest i guess. So about 40 pulses for 10 cm, good enough? I think thats pretty good to me already. Cool thing is that, in the old mouse, there is this black strip of black plastic, which has small slits on it, to focus the ir led transmissions to the sensor so as not to miss out any spaces in the encoder wheel. Pretty awsome! I am having one problem now, I am unable to make the micromouse go in a straight line, any ideas why? The voltage to both motors are the same. I also need to ask you do i need to take not if whether the wheels are going foraward ad backward with the encoder? Thanks alot mate

mouse encoders

by peteh - 01/06/2010 - 01:07
If you have taken the emitter/sensor out of the mouse as well, you will find that the sensor has two outputs. These are in quadrature and can be used to find out what the motor direction is. The mouse pictured above does that. You will need to know.
I would think that, for now, four counts per mm would do you.
Mice rarely go in a straight line if left to their own devices. That is why you need the control loops in there. The motors may be un-matched and the wheels are unlikely to be the same diameter.

You mean 1cm for 4 pulses

by Patrick (not verified) - 01/06/2010 - 12:59
You mean 1cm for 4 pulses right? One other sad thing is that, the mouse i bought, had two sensors per disk. and the sensors had only 2 legs each. Oh well. would it be smart though, to place variable resistors to the motors so as to control the voltage to make it go in a straight line? I checked and voltage to both motors are the same. THanks alot for your help peter

mouse encoders

by peteh - 01/06/2010 - 14:56
If the encoders have two legs, there are two of them and you need to use both. Most folk cut up the mouse PCB and attach leads to it to preserve the geometry. Try to get all the encoder resolution you can. If you must vary the drive to each motor, do it by adjusting the PWM going to each one rather than variable resistors.

Speed

by Patrick (not verified) - 02/06/2010 - 03:03
Damn I cut soldered apart the PCb alr. One thing, is 1.1m/s too slow ? I'm trying to get it faster. I'm currentylu using those micrometal gear Motors and running at 9vs . Any suggestion on how to increases top speed

Fast enough will do

by peteh - 02/06/2010 - 09:23
For a first mouse, the most important thing is getting to the middle. When you can do that reliably, then work on making it faster

Alright, will work on that.

by Patrick (not verified) - 02/06/2010 - 13:43
Alright, will work on that. but errrrr, how do i accel? do i need some sort of speed profile? if so, how would i generate one?

hi again peter, could you

by Patrick (not verified) - 09/06/2010 - 14:26
hi again peter, could you enlighten me on the speed controlling with the code to do things like accel decel and constant speed of a micromouse? I know that pwm is involved but i dont know how to apply the code. Many thanks.

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