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Subject: 
Re: SSClagorpion
Newsgroups: 
lugnet.technic
Date: 
Mon, 19 Apr 2004 16:19:43 GMT
Viewed: 
8432 times
  
In lugnet.technic, Steve Hassenplug wrote:
In lugnet.technic, Kevin L. Clague wrote:
In lugnet.technic, Steve Hassenplug wrote:
In lugnet.technic, Kevin L. Clague wrote:

Ignoring side walking for a moment.....

  1) One motor to turn a single switch on/off.  This allows or prevents walking.

  2)  One motor to flip 8 switches.  This one controls walking vs. turning.

  3)  One motor to flip 8 switches.  When walking, this one controls forward vs.
backwards.  When tuning (in place), this one controls right vs. left turning.


That was my second choice.

Ok, three motors.


I still think walking sideways is cool, but optional.

It is still on the list, I was just leaving it out of the equation for a moment.


Ok, so what's required for walking sideways?  One switch (= single set of
switches, all activated at once) to switch from forward/back/turn to
side-to-side?  I'm sure that comes to about 16 reverser switches, or something.
:)

It is my belief that sideways walking will require a third degree of
articulation in the leg/hip structure.  It will cause the legs to swing towards
and away from the body.  By replacing the forward/backward part of the leg sweep
with the side to side leg sweep we should be able to walk.

I'd guess 16 also.....  We'd need 8 to swap the side to side motions for the
forward back sweep, this gives us one direction of side walking.  We'd need
another 8 to swap the direction sweep so that we can walk toward the other side.

Looks like the sideways muxes will need a motor.  We can probably use the
forward/backward motor to also control the right/left muxes as well.


I just happened to think, the legs should be in a known position when switching
from forward/back to side-to-side.

Do the legs need to be in a know position when switching from forward to
backward?  Or walking to turning?  If so, we need sensors for that...

Yes.  Changing the forward/backward/turning muxes needs to be done when the feet
are in the air.  Observing any one foot is probably sufficient.

The above costs us four motors, and one sensor.



Here's my current bill of materials:
1 Spybot, for IR direction control.  This is mostly used as a sensor.
2 RCXs.  I really haven't counted I/O, but two sounds like enough.
1 Battery box for compressor(s)

All those should be installed in the body of the beast.  The Spybot/RCXs will
need to communicate via IR.  (there are other options, but we'll start there)

The Spybot has two motors, but very limited sensor feedback.  It would be good
to use the Spybot motors to activate something like claws (open & close), where
it won't be critical if they work exactly right.  We can use the Spybot remote
to send it commands, like "follow me" or "attack anything in front of you"

All the outputs from 1 RCX control movement. 1=Activate, 2=function
(turn/straight), 3=forward/backward

Until you try side to side walking.


Two inputs would be used for sensing the edge-of-table.  That's one input for
each front leg.  Each leg would have one sensor to detect when the leg is in
it's "down" position, and one sensor to detect the ground.  The two sensors in
each leg can be connected together, to use one input.  This could be two touch
sensors, or a touch+light sensor combination.

Two inputs can be used for the arm "feelers".  Maybe several touch sensors per
arm, or one rotation sensor for each.


I'm not sure the RCXs really need to "know" when the SSClagorpion is actually
walking.  It can assume if it runs the motors, then the switches are set, and it
is going.

Yes, I think it can assume that if it has set the switches correctly it is
walking.


Beyond that, there is one motor to set the switch for curling the tail.

That leaves 2 motor outputs, and 2 sensor inputs, for further expansion.  Plus a
touch sensor & light sensor built into the Spybot.  The outputs from the second
RCX can be connected to a gearbox, like Eric was suggesting, if we want to
control more things, but I think that may just make things more complex than
they need to be.


It would be nice to mount the Spybot in the end of the tail, but it needs to
communicate with the RCXs via IR, so I don't think that will work well, unless
we connect a fiber-optic line.  No, I don't think that will work, either.


So, SSClagorpion will walk forward & backward, turn right & left, open & close
two claws, and move it's tail.  It can stay on a table/stage, detect when it
bumps into something (going forward), follow the "controller" or be driven
around like an RC car.

Is that enough cool functionality?

It works for me!


Steve

Kevin



Message has 1 Reply:
  Re: SSClagorpion
 
(...) Ok, we [plan to] have a sensor on the front foot, and can detect when that is down. So, no more sensors are required. So you said, the forward/backward must be changed while the feet are in the air. We've been thinking of having a touch sensor (...) (20 years ago, 19-Apr-04, to lugnet.technic)

Message is in Reply To:
  Re: SSClagorpion
 
(...) Ok, so what's required for walking sideways? One switch (= single set of switches, all activated at once) to switch from forward/back/turn to side-to-side? I'm sure that comes to about 16 reverser switches, or something. :) I just happened to (...) (20 years ago, 19-Apr-04, to lugnet.technic)

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