www.robowars.org

RoboWars Australia Forum Index -> Rules, Safety, Administration

The Eternal Walker Debate
Goto page 1, 2, 3, 4, 5, 6, 7  Next

Post new topic   Reply to topic
  Author    Thread
Spockie-Tech
Site Admin


Joined: 31 May 2004
Posts: 3160
Location: Melbourne, Australia


 Reply with quote  
The Eternal Walker Debate

ok, this is where the never ending walker discussion can happen.

Post Sun Jun 20, 2004 1:33 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
Rob Team Rotwang



Joined: 19 Jun 2004
Posts: 294
Location: Victoria


 Reply with quote  

I like the idea of walkers; they look really cool much more interesting then most robots running on wheels. They don’t necessarily make a real effective Fighting robot. Someone may attempt to build one once there is a bit more money going around in the competition to cover the building costs.
I think people might have a hard time getting them in the weight limit also Confused

Post Sun Jun 20, 2004 4:36 pm 
 View user's profile Send private message AIM Address MSN Messenger
Knightrous
Site Admin


Joined: 15 Jun 2004
Posts: 8511
Location: NSW


 Reply with quote  

I'm still toying with my walker idea, I might be able to make a start to it one day when i get some time on my hands.

Probably won't qualify for Brett definition, but I will have 8+ legs and they will move up/down and forward/backwards with out a circular motion like Anarchy.

Weapon planned...... Flipper.
_________________
https://www.halfdonethings.com/

Post Sun Jun 20, 2004 5:31 pm 
 View user's profile Send private message
Nexus
Experienced Roboteer


Joined: 17 Jun 2004
Posts: 903


 Reply with quote  

Its not Bretts definition but Brett just tries to keep us honest. I hope we can discuss this further as Walker rage isnt useful. I dont mind throwing up some thoughts based on what i have previously stated just to stir the pot.
It does make sense that if a shuffler only has to move on the vertical axis and a walker has to move on vertical and horizontal then the walker needs twice the amount of actuators and gets a bigger bonus. If you where to animate this in a 3d package you could animate a shuffler using only one dimension but a walker would need you to go back and forth between 2 different dimensions. for ease lets just say X and Y as opposed to just x.
Before we bring up cams and thingymebobs hope we can resolve the walker definition. Its funny how evolution turned reptiles into dynosaurs. Again as previously stated. The difference is that dynosaurs developed narrower stronger hips, stood taller and sort of became a shuffler or a bird in robot terms but its the walking reptiles that are still around today with those damn dirty birds.
_________________
Bots that do not destroy you, only make you stronger.

Post Sun Jun 20, 2004 6:39 pm 
 View user's profile Send private message
Knightrous
Site Admin


Joined: 15 Jun 2004
Posts: 8511
Location: NSW


 Reply with quote  

Umm, correct me if I'm mistake, but isn't the Y axis Verticle and the X axis is Horizontal.

So if a shuffler is to only work in a single plane such as the X axis, that means it's leg will only go forward/backwards, not effectively moving the robot. It would have to travel up/down in the Y axis to lift off the ground and place it's leg back down to travel a stride.

To walk like a crocodile, you will need to have a leg that works in the X,Y & Z axis to be able to "crab" sideways.
_________________
https://www.halfdonethings.com/

Post Sun Jun 20, 2004 7:01 pm 
 View user's profile Send private message
Nexus
Experienced Roboteer


Joined: 17 Jun 2004
Posts: 903


 Reply with quote  

Yeah i prob got the x and y backwards but I think you get the jist.
Forward backward as well as up and down. forward movement is done by lifting then leaning forward then lifting then leanng forward as pairs.
You still only need 2 for a croc in essence. You could have a pivot point in the body if you wanted more articulation. THis does work for 6 legs as well.
_________________
Bots that do not destroy you, only make you stronger.

Post Sun Jun 20, 2004 7:11 pm 
 View user's profile Send private message
colin



Joined: 16 Jun 2004
Posts: 102


 Reply with quote  

quote:
Originally posted by teamvertex:
Umm, correct me if I'm mistake, but isn't the Y axis Verticle and the X axis is Horizontal.

So if a shuffler is to only work in a single plane such as the X axis, that means it's leg will only go forward/backwards, not effectively moving the robot. It would have to travel up/down in the Y axis to lift off the ground and place it's leg back down to travel a stride.

To walk like a crocodile, you will need to have a leg that works in the X,Y & Z axis to be able to "crab" sideways.


you could define the axis any way you want. Just like when you use gravity you can make it positive or negative, it doesn't really matter. maybe we should change over to polar coordinates instead of cartesian.

Post Sun Jun 20, 2004 7:23 pm 
 View user's profile Send private message
Nexus
Experienced Roboteer


Joined: 17 Jun 2004
Posts: 903


 Reply with quote  

Not sure if I am being clear. A leg can be lifted, moved forward, moved back and put back down but thats all possible on one axis or dimension. An easy way to visualise this is that the sequence just desribed can be drawn on a sheet of paper, making it one plane. It needs to go up, down, forward, back as well as left to right which is on anothger axis. Up and Down is only half an axis. THink of a compass and if you use North and south to go up and down u still have east and west to go forward and back, all on the same axis. It doesnt let you go left and right as well, the course the leg is required to take becomes a 3d image. X,Y and Z as you correctly pointed out. Thats probably the confusing thing in all this. 2 DOF is XYZ and 1 DOF is X & Y
_________________
Bots that do not destroy you, only make you stronger.

Post Sun Jun 20, 2004 7:35 pm 
 View user's profile Send private message
colin



Joined: 16 Jun 2004
Posts: 102


 Reply with quote  

quote:
Originally posted by MachineHead:
Up and Down is only half an axis.


you can have have an axis?

Post Sun Jun 20, 2004 8:31 pm 
 View user's profile Send private message
Nexus
Experienced Roboteer


Joined: 17 Jun 2004
Posts: 903


 Reply with quote  

Yeah ok probably not the best choice of words, does get confusing as we start with degrees of freedom and i am just trying to descibe it in other terms to try and visualise it to rattle out an easy explanation. I just hope others are genuinely interested to resolve this, no need to dot my i's and cross my t's. This stagnant topic is not an old episode of star trek that we have different opinions on, even though thats the best explanantion so far. Its just maths
_________________
Bots that do not destroy you, only make you stronger.

Post Sun Jun 20, 2004 9:15 pm 
 View user's profile Send private message
colin



Joined: 16 Jun 2004
Posts: 102


 Reply with quote  

quote:
Originally posted by MachineHead:
Yeah ok probably not the best choice of words, does get confusing as we start with degrees of freedom and i am just trying to descibe it in other terms to try and visualise it to rattle out an easy explanation. I just hope others are genuinely interested to resolve this, no need to dot my i's and cross my t's. This stagnant topic is not an old episode of star trek that we have different opinions on, even though thats the best explanantion so far. Its just maths


I didn't mean to have a go at you. I just don't follow what you are talking about at all. I am a little bit worried by that. I'm in the third year of my engineering degree and have a machine design exam on tuesday. It worries me that I have no grasp of what your talking about. Especially when it relates to what i'm studying.

Post Sun Jun 20, 2004 9:46 pm 
 View user's profile Send private message
Spockie-Tech
Site Admin


Joined: 31 May 2004
Posts: 3160
Location: Melbourne, Australia


 Reply with quote  

I have to say you've confused me as well there George.. Confused

I'm not a maths guru, but the X,Y,Z = 3 Degress of Freedom = 3 Axis always seemed fairly cut'n'dried to me..

Maybe you're trying to express something else entirely, but as far as I know a piece of paper is 2 dimensional, so is the motion of crankshaft or anarchy's legs Razz

Post Sun Jun 20, 2004 10:10 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
Knightrous
Site Admin


Joined: 15 Jun 2004
Posts: 8511
Location: NSW


 Reply with quote  


quote:
I'm not a maths guru, but the X,Y,Z = 3 Degress of Freedom = 3 Axis always seemed fairly cut'n'dried to me..


I'm not insane Shocked I was starting to get confused over all this stuff. George, stop confusing us Very Happy

What about if I/anyone can make a mechanism that will make the leg lift up/down with out any circular movement like Anarchy. And to the same with the horizontal movement on the leg?
_________________
https://www.halfdonethings.com/

Post Sun Jun 20, 2004 10:26 pm 
 View user's profile Send private message
Nexus
Experienced Roboteer


Joined: 17 Jun 2004
Posts: 903


 Reply with quote  

Dont mean to confuse. Have confused myself a bit but will sort this out. firstly just because i refer to xyz it doesnt mean 3 dof. it is just a physical space to work in. if a leg is lifted with actuator 1 say straight up then actuator 2 moves the leg horizontally from forward to back before actuator 1 puts it back down, it moves on 2 planes (2 DOF) what i was trying to say was that even though it is 2 dof the combination of the two moving together seem to move through 3d space.
Some shufflers movements can be shown on a piece of paper in a 2d drawing like looking at the drive wheel mechanism of an old steam train which is sort of like a cam and can be shown with a 2d drawing but legs moving with 2 dof are shown better in a 3d world environment as they dont move like a shuffle
Maybe the 3d metaphor doesnt work to desribe how a 2dof leg moves in space. Sorry to confuse you all.
I know i have used wrong terms to describe things.
_________________
Bots that do not destroy you, only make you stronger.

Post Sun Jun 20, 2004 11:23 pm 
 View user's profile Send private message
prong
Experienced Roboteer


Joined: 19 Jun 2004
Posts: 839


 Reply with quote  

Ok this all gets confusing, so i have decided to add my own ideas to confuse it some more! Laughing
the way i see it

a shuffler can move the leg up and down and forward and backward, but can only do this in a set circular pattern. This walking motion can be powered by a single motor, and to reverse the direction of walking the motor just reverses. This is like those little toy windup robots you can buy.

a true walker can move the legs up and down and forward and backward, but can move up and down seperately to forward and backward. This means you have a motor that moves the leg up and down, and another one that moves it forward and backward. This means you can control each motor seperately, so you robot can do things a shuffelr cannot. This includes raise or lower all legs to make to robot higher or lower (or of course just raise or lower one end etc). Having more control also means you can have different walking patterns etc.

i dont know how clear this is to everyone, so if you want me to explain more then let me know. Of course this is just my idea of what a walker should be.

Post Sun Jun 20, 2004 11:30 pm 
 View user's profile Send private message Send e-mail
  Display posts from previous:      

Forum Jump:
Jump to:  

Post new topic   Reply to topic
Page 1 of 7

Goto page 1, 2, 3, 4, 5, 6, 7  Next

Forum Rules:
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

 

Last Thread | Next Thread  >
Powered by phpBB: © 2001 phpBB Group
millenniumFalcon Template By Vereor.