Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: henno2000 on February 21, 2007, 12:31:25 PM

Title: Noob: Quadruped Walker Circuit Design
Post by: henno2000 on February 21, 2007, 12:31:25 PM
Hi,

I have been browsing your interesting site for the purpose of research & development.

I have been given a brief of the following:

Research, Design and Simulation of Quad-pedal Robot

The typical generic requirements of a standard electrical system to be researched, designed and simulated are as follows:

1.       To enable the quad pedal robot to detect light source and move towards the source.

2.       To enable the quad medal robot to walk towards the light source

3.       To simulate the open-loop system in respect of the robot moving under its own power and walking towards the light source

 

The typical generic requirements of an advanced system are as follows:

1.       Simple hard-wired control of the robot to create a closed loop system, enabling the robot to walk towards the light source

2.       A simple controller e.g. P, PD, (classical control)

3.       A simulation of the closed-loop system



Do you think a BEAM robot would be best suited to this criteria? I am an amatuer on this topic, but from what I have read from your site and topics on the web , it seems to be the fact I keep returning to this.

At the present time I am trying to concentrate on the electronic aspect of the design.

If possible, could someone give me some pointers/advice on circuit design and can you recommend any books/literature/reference aids that will help me with my investigation?

Any information would be greatly apprecciated

Many thanks in advance
Title: Re: Noob: Quadruped Walker Circuit Design
Post by: trigger on February 21, 2007, 12:35:02 PM
Here's a BEAM robot with a microcontroller (so not really BEAM, but close):

http://www.instructables.com/id/EYLB2BCA9BEUGCWIZL/

Stick a CdS sensor on this thing and you're good to go.
Title: Re: Noob: Quadruped Walker Circuit Design
Post by: henno2000 on February 21, 2007, 01:05:00 PM
Thanks for the reply.

I am assuming that a BEAM robot will provide a solution to my question?

Are there any others that would suit better.

Could someone give me some tips on circuit design regarding light detection and also how to stop the robot from bumping into obstacles? (IE - When a surface is detected, make it turn direction/reverse)

Many thanks
Title: Re: Noob: Quadruped Walker Circuit Design
Post by: trigger on February 21, 2007, 01:23:39 PM
Thanks for the reply.
np

Quote
Could someone give me some tips on circuit design regarding light detection and also how to stop the robot from bumping into obstacles? (IE - When a surface is detected, make it turn direction/reverse)

Many thanks
There are tutorials on this site for doing just that. http://www.societyofrobots.com/programming_photoresistor.shtml
Title: Re: Noob: Quadruped Walker Circuit Design
Post by: henno2000 on February 21, 2007, 01:46:02 PM
Excellent, thanks again.

From what I can see, the site seem very informative. I cannot see any FULL schematics though. (IE - for the photovore robot) Was looking for something like this to work from if possible to & to possibly develop further.

Many thanks
Title: Re: Noob: Quadruped Walker Circuit Design
Post by: Admin on February 21, 2007, 08:01:02 PM
Do you plan to sell your robot? (Are you a VC? ;D)

What are the requirements of the legs? Simple leg movements can be done with BEAM.

A BEAM type robot will be able to achieve what you want, and would be cheaper than say putting a microcontroller on your robot, but it isnt always the best way to go if you want very intelligent actions.

Look up 'photovore', as what you want is just a photovore with legs.

an example of a quadruped robot with a microcontroller:
http://www.youtube.com/watch?v=HuQvY7ocvlU

i think this robot is BEAM (i say 'think' because its simple and it can be done with BEAM)
http://www.physlink.com/estore/cart/MoonWalkerRobotKit.cfm
Title: Re: Noob: Quadruped Walker Circuit Design
Post by: henno2000 on February 22, 2007, 01:45:08 AM
Thanks,

Regarding the mechanics of the robot, I am not bothered about these for the time being, just the actual circuit design/schematic.

As for the fact of it being a BEAM robot, I was asking if this would correctly suit my criteria, or is there a better solution?
Title: Re: Noob: Quadruped Walker Circuit Design
Post by: Admin on February 22, 2007, 11:21:15 AM
Quote
As for the fact of it being a BEAM robot, I was asking if this would correctly suit my criteria, or is there a better solution?
Well the point I was trying to make is that using a microcontroller and taking the BEAM approach are very different methods to make this robot. The method that is best depends on your end goal.

If you are just building the robot for fun and your own personal education, and dont know how to analyze a circuit, I suggest staying away from the BEAM approach.

For the microcontroller approach, buy a microcontroller (no need for schematic) with included source code. Attach some servos, two photoresistors, a battery, and your set. No need to do any complex circuitry.

For the BEAM approach, it requires a fairly complex circuit. It also greatly depends on what walking gate you require, so we would need more information on what you want . . .
Title: Re: Noob: Quadruped Walker Circuit Design
Post by: henno2000 on February 23, 2007, 08:08:41 AM
Was just looking for a simple solution, with either PIC, PID or op-amp controller which enables the robot to move towards a light source

Thanks
Title: Re: Noob: Quadruped Walker Circuit Design
Post by: henno2000 on March 01, 2007, 10:39:56 AM
Can someone recommend a list of common microcontrollers and servos?

Many thanks
Title: Re: Noob: Quadruped Walker Circuit Design
Post by: JesseWelling on March 03, 2007, 02:39:22 AM
AVR atmega 128 is a pretty good one.
I don't particularly like PIC but some people do.
I havn't used an ARM7 but I hear they are pretty neat.

I'd stick with an ARM7 or an AVR and use GCC and linux make your projects....but that's me....
Title: Re: Noob: Quadruped Walker Circuit Design
Post by: Admin on March 03, 2007, 04:06:01 PM
if you want to be ultra simple, cheap, and dont care for special features, id go for a basic stamp (just make sure it has two analog to digital converters to use for your photoresistors)
Title: Re: Noob: Quadruped Walker Circuit Design
Post by: henno2000 on March 11, 2007, 05:35:49 AM
Thanks, for basic functionality is it best advised to use a PIC.

From people's previous experience, are there any advantages/disadvantages using a PD controller?