Alt-BEAM Archive
Message #09297
To: beam@sgiblab.sgi.com
From: Dave Hrynkiw dave@solarbotics.com
Date: Mon, 17 Jan 2000 18:00:40 -0700
Subject: [alt-beam] Re: Interseting, additional idea..........................
At 02:07 PM 1/17/00 , jester96beam@iname.com wrote:
> > BTW, I've got my servo motors in the mail, so I'm ready to start building
> > my first walker!
>
>Speaking of servos - I oredered 5 from Dave a while ago. How long should
>it take to get them to Ontario from when I mail the order? I think I
>should have paid the extra money for purolator.
When we get your order (about 3-4 days in the mail), we send it out usually
next day (3-4 days back).
-Dave
---------------------------------------------------------------
"Um, no - that's H,R,Y,N,K,I,W. No, not K,I,U,U, K,I,_W_. Yes,
that's right. Yes, I know it looks like "HOCKYRINK." Yup, only
2 vowels. Pronounciation? _SMITH_".
http://www.solarbotics.com
9298 Mon, 17 Jan 2000 19:13:49 -0600 [alt-beam] Re: Interseting, additional idea.......................... beam@sgiblab.sgi.com Richard Piotter Hey, don't feel bad! I stayerd up till 2 or 3 in the morning finishing
up that circuit and making sure no logic conflicts could occur. The next
morning, I looked at it and was completely lost!!! I designed the thing
and it took me 5 hours to "re figure" it out!!! HAHAHA!!!
The circuit reached a point where I was no longer able to accurately
represent it with boolean algebra (too many loop latches and variations
that I simply couldn't figure it out by the numbers). I have a logic sim
program on my Macintosh that handled the first section perfectly. I
didn't have the memory or processing power for the rest of the circuit
at the time. I should try it on my G3. Can't believe I never thought of it!!!
Anyway, to give you a clue, reversing certain motors affects the gait.
The circuit uses a sort of a logic H-Bridge to reverse the signals
leading to the motors. Some motors have to be stopped for the proper
gait effect to be done. I simply have AND gaits set up to block the signals.
The first major portion of the input circuit is a latch. Stop kills the
forward and reverse latch. This circuit indirectly drives the logic
h-bridge that reverse the pulses for forward or reverse motion. It only
needs a pulse to start. There is a reason for this. If the robot is
stopped and you send a right or a left signal, it'll turn in that
direction on a dime. This reverses one side of the robots legs so it
rotates in the proper direction. If the bot is walking, the signal from
the FWD/REV latches goes to an inverter and prevents the side that must
reverse from reversing, rather, it blocks the signal, so one side walks
in place as the other walks forward or reverse, giving you two degrees
of turning, rotation around the center and rotation around it's side. If
both keft and right kick in it will block both the light and right
commands themselves from the controller and block the user direction
input and reverse itself. For example, if sensors were added to detect
obstacles and would turn it left or right, and one was dead ahead, it'd
force it to reverse. Due to chaos, it'd eventualy trigger only one first
and would turn, or slight time delays can be thrown in to bias it to one
direction too. Sensor circuitry is not in the schematic though. This is
just an example of use. Stop blocks all the inputs and releases all latches.
The H-Bridges are just one of many potential motor driver circuits. I
may infact use a PWM circuit and some logic for the motor controls in
this robot. It all depends on what I figure out will work best. There is
also a possibility that instead of using the physical logic chips, I may
opt to use a microcontroler for energy savings and space savings. I also
need a DTMF decoder, and the BASIC Stamp has such an option. If I
planned on one anyway for that purpose, then why not use it to it's full poitential!
I do like that the hard logic would be more stable in the event of a
storm of people rattling their keys over it's boards though, plus I
already built the circuits!!! :)
Bruce Robinson wrote:
>
> I remember trying to analyze Richard's Quadrapod circuit when I first
> got into BEAM. Never did entirely figure it out, even though I was
> familiar with logic circuitry.
>
> Since then I've built a number of complex nervous nets and wrestled with
> the problem of making them extremely flexible. Here's an entirely
> different scheme.
>
> Build a separate nervous net for each gait or motion you want (that is,
> a separate circuit for each different arrangement of Nv's). For each
> circuit provide two inputs ... a "turn off" input (kills all processes,
> using diodes), and a "turn on" input (starts up precisely the processes
> you want, using diodes and a couple of inverters).
>
> To control the gait, you kill the circuits you don't want, and start the
> circuit you do want.
>
> To operate the motors/drivers, you need to combine the outputs from all
> the gait circuits. This is easily done with NAND gates, which happen to
> be available in a great many configurations: 2-input, 3-input, 4-input,
> 8-input.
>
> I've done this on the breadboard, and it works very nicely. The big
> advantage is you can tune each neural net circuit separately, so each
> one works exactly the way you want for a particular gait. If you build
> each neural net on a separate circuit board, you can add or replace
> them to experiment with new gaits.
>
> I can't give you a precise comparison to the method Richard used until I
> figure out all the possible combinations of his inputs. My rough
> estimate is that the chip count would be the same, assuming each of his
> input combinations needed its own neural net.
>
> Not necessarily a better idea, but certainly a different approach.
> Details on request.
>
> Regards,
> Bruce
--
Richard Piotter The Richfiles Robotics & TI web page:
richfile@rconnect.com http://richfiles.calc.org
-- Make Money by Simply Surfing the Net or responding to E-Mail!!!
-- Click below!!!
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9299 Mon, 17 Jan 2000 20:18:31 EST [alt-beam] Re: Interseting, additional idea..................... beam@sgiblab.sgi.com Meabadboy@aol.com In a message dated 1/17/2000 2:10:33 AM Eastern Standard Time,
richfile@rconnect.com writes:
<< I'll answer two things here. I came up with a possible design for a
combination Triangular Single Nv/Nu Configurable Hextile that can be
trimmed and converted to a DIP type package. This DIP package is 8 pins
with an SMT LED, or if you don't want a LED, you can trim it to a mere 6
pins!!! I like the idea of having LEDs, but it's also nice to know they
can be removed (ie. solar powerd bots and energy conservation).
The file was drawn up my myself and is included as an attached GIF file.
If you view it on a true scale screen, it SHOULD display it near 1x size
I think. Easiest way is to take a ruler against your screen and measure
against an on screen ruler. Worked for me!
>>
Humm ~ verry intersting idea and approach ~ so............
when will u have 'em ready to sell and how much each??
Steve
9300 Monday, 17 January 2000 6:15 Re: Interseting, additional idea.......................... beam@sgiblab.sgi.com Richard Piotter
>I'll answer two things here. I came up with a possible design for a
>combination Triangular Single Nv/Nu Configurable Hextile that can be
>trimmed and converted to a DIP type package. This DIP package is 8 pins
>with an SMT LED, or if you don't want a LED, you can trim it to a mere 6
>pins!!! I like the idea of having LEDs, but it's also nice to know they
>can be removed (ie. solar powerd bots and energy conservation).
>
>The file was drawn up my myself and is included as an attached GIF file.
>If you view it on a true scale screen, it SHOULD display it near 1x size
>I think. Easiest way is to take a ruler against your screen and measure
>against an on screen ruler. Worked for me!
>
>
>
>Next, someone mentioned using logic gates and BEAN technology together...
>
>If you look at my web page and look under Quadrapod, you'll find a link
>to a schematic. It uses an Nv loop to generate a drive sequence, but
>gates to translate 5 input signals (Stop, Forward, Reverse, Left, and
>Right) into changing pathways for the Nv processes, resulting in 9 types
>of gaits (Stoped, Forward, Reverse, Rotate Left, Rotate Right, Walk
>Forward & Left, Walk Forward & Right, Walk Reverse & Left, and Walk
>Reverse & Right).
>
>I intend to add more circuitry to accept manual commands or switch to
>autonomous command where it accepts commands from internal sensors. If I
>get lucky, I might get my hands on some cash and be able to actualy
>build it. Also, rather than use H-Bridge drivers, I'm using the output
>signals to drive a PWM generator to create 4 modes (Hold, Up Middle, and
>Down). This will give the robot the ability to keep an organized gait
>and even be able to level itself when stopped. Important since I have a
>tiny camera to go on it!
>
>And I sure wish I could play with some GAL or PLA. My college has a PLC
>class (sorta like GALs and PLAs with driver circuitry for driving thing
>like industrial motors and such, or it looks like that anyway).
>
>
>
>
>Meabadboy@aol.com wrote:
>>
>> In a message dated 1/16/2000 9:38:21 PM Eastern Standard Time,
>> richfile@rconnect.com writes:
>>
>> << It'd be nice to see the single Nv hextile actualy consist of the
pattern
>> for the DIP
>>
>> You simply cut the PCB around it and solder a pair of male header pins
>> into through holes made into the board. Perfect solution to both the
>> people looknig for a DIP and those wanting the little triangle
hextile!!! >>
>>
>> Sounds like a viable solution to both types of intrests ~ but "SMALL" is
>> definatly the key here if I understand what the whole theme of this is.
>>
>> When will you have any available for sale????
>>
>> LoL
>>
>> I am hooked on this idea.
>>
>> I do like the idea of the single unit approach ~ I have played a bit with
>> this idea myself...
>>
>> Off topic here......... and just a thought I had hit me while reading all
the
>> information on your individule websites and also after I saw the TV show
last
>> night on the learning channel on this whole idea/approach to robotic
control
>> ~ verry novel approach this is indeed ~ only one thought...............
>>
>> In his interview, he discussed the idea that with a microprocessor (or
Robot
>> brain) ~ if a portion of the circuit (he diminstrated this with dropping
a
>> set of keys on the circuit bord) was damaged the whole works was "ka-put"
~ I
>> agree with this example having myself played with microprocessors ~ one
>> glitch and its back to the @#$%# workbench ~ and his major point to this
BEAM
>> approach ~ however ~ in any living creature we are trying to mimic/copy ~
>> insect, reptile, etc...... that I have read about, there is a central
point
>> where all the information comes togeather and is "Processed" ~ or for a
lack
>> of better words a BRAIN ~ or in most robotics ~ a microprocessor ~
>>
>> How if all we are dealing with here is the "nerves" of the creature are
we to
>> assemble a creature that can make judgement upon conditions other then
just
>> "Reflex"?
>>
>> I mean "Reflex" in terms of how the BEAM circuit reacts to the change of
the
>> RC time constant via sensors or the output of the previous NV/NU.
>>
>> As for the BRAIN or central processor of the creature ~ Has anyone looked
at
>> the possibility of useing AND/NAND gates as a make up for decision logic
>> along with the RC timeing network of the inverter?
>>
>> Or replacing the inverter with a AND/NAND gate of the same type of
>> construction.
>>
>> Maybe even X-OR/X-NOR circuits along this theme of RC timing?
>>
>> I havent had the time to play with a AND, NAND, XOR gate yet to see if it
>> will exibit the same type of timing/reaction and operation/trigger on the
>> rise of the RC charge as does the inverter commonly used in the NU/NV
>>
>> Just courious.
>>
>> I also wonder if this will work along with a GAL or PLA for more complex
>> logic.
>>
>> Steve
>
>--
>
>
>Richard Piotter The Richfiles Robotics & TI web page:
>richfile@rconnect.com http://richfiles.calc.org
>
>-- Make Money by Simply Surfing the Net or responding to E-Mail!!!
>-- Click below!!!
>
>http://www.alladvantage.com/go.asp?refid=ATL147
>http://www.spedia.net/cgi-bin/dir/tz.cgi?run=show_svc&fl=8&vid=329630
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