Alt-BEAM Archive

Message #09309



To: beam@sgiblab.sgi.com
From: Richard Piotter richfile@rconnect.com
Date: Mon, 17 Jan 2000 22:53:04 -0600
Subject: [alt-beam] Re: Interseting, additional idea..........................


Another addition. I looked at teh circuit and confused myself again.
Rather than 4 reverse circuits for the 4 reversible motors, I have 2
redundant reverse circuits. I want forward, reverser 1 remains normal
and reverser 2 remains normal. If I want it to reverse, I reverse
reverser 1. reverser 2 remains normal. It's inline with reverser 1 and
when 1 switches, both pairs of motors switch. If I want to turn one way,
I switch the second reverser. cause it branches after the first, one
pair of motors remains normal and the other switches direction. if I
want to turn the other way, I reverse both reversers, and it inverts
which motor pair gets the switched outputs. Works great, and cuts chip
count by at LEAST half (for the reversers).

That may also have confused you a bit. I know it still confuses me!

And to think, I designed the thing from scratch. I ought to know how it
works! :)


Richard Piotter wrote:
>
> 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!!!
>
> 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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richfile@rconnect.com http://richfiles.calc.org

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9310 Mon, 17 Jan 2000 23:12:27 -0600 [alt-beam] Re: Interseting, additional idea.......................... beam@sgiblab.sgi.com Richard Piotter Remember, the traces can lead to the external pins. Not necicary to
realy require th jumpers there. The only jumpers you'd need would
determine Nv or Nu, Neuron polarity, and LED polarity (it is possible to
use a positively active Nv or Nu, where it fires positive and sits at
ground, opposite of most in use. This would require the LED to be
reversed and the power connection attached to the opposite polarity). It
could be possible to have trace breaks where you can cut the traces to
configure it, or even have it defaulted to negative Nv, but have it so
you could cut one trace and solder another to switch configurations. I
only worked on the inner portion, the part that does the work, and also
doubles as a DIP device. I'll leave it to the hextile desgner to
determine the best way to add the external configuration and traces and
conenctor pads. I've had that DIP on paper for over a year. I just never
thought to put it on a hextile. The DIP portion of the board would not
need that configurtation stuff, as it can be done on the breadboard or
PCB it's mounted to. That saves space. The hextile though would need
those configuration points. Nothing more than a dab of solder and an
x-acto knife to change from Nv to Nu, or from (-) polarity to (+)
polarity and to switch the LED polarity. The LED polarity could be
determined by a set of configuration pads above the LED and Resistor, so
the LED would not require desoldering and it could be easily configured.
There would only be one pad to cut on the DIP area. That's between the
resistor and LED. Power can lead to each side of the LED through the
configurable pads from above the DIP area. the resistor can lead around
to the other side of the LED for anotehr configuration pad. This allows
TOTAL control of the neuron's opperation. Nv or Nu, (+) or (-), or LED
on or off with a process, with the ability to disable the LED.

I'll draw up more detail if this description doesn't efficiently
describe the jumperless configuration for the hextile. I'd prefer to
leave the design of the hextile portion to the person who designs it,
but I think the gif I sent describing the DIP portion and overall layout
is about as good as it gets.

Maybe I'll come up with a new pic later.


David Perry wrote:
>
> I like it! But i still have a problem with the connectors, this requires
> soldering and a lot of hook up wire to connect to a hextile, your inner
> circuit is perfect though. Will the triangle hextile work with 2 sides being
> output and one input? Would this allow flexibilty to create all th needed
> shapes?
>
> David
>
> -----Original Message-----
> From: Richard Piotter
> To: beam@sgiblab.sgi.com
> Date: Monday, 17 January 2000 6:15
> Subject: Re: Interseting, additional idea..........................
>
> >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

--


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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9311 Mon, 17 Jan 2000 23:27:26 -0600 [alt-beam] Re: Pertaining to the Hextile things. You should really make them beam@sgiblab.sgi.com Richard Piotter I could see them being mounted verticaly like that, but you'd need ALL
the outputs on one side, and it's also harder to see the LEDs if you
mount them inline on a PCB backplane, although that too is a good idea.
DIP is a proven circuit package. and I suppose a SIP would be acceptable
too. Still, vertical mounting makse seeing the LED more dificult when
you want it visible.

Dane Gardner wrote:
>
> If you have header pins on a tri-tile you could breadboard them as well. It
> would actually be easier than a DIP. You could even have a SIP socket
> onboard for inputs and biasing. that would cut back on the ammount of space
> necisary to wire several dips.
>
> CYA,
>
> Dane
>
> Subject: Re: Pertaining to the Hextile things. You should really make them
> hextiles and not DIP
>
> > If it's expirimenting we're talking about, then DIP is the BEST
> > solution, as it would work on breadboards, and could be placed into
> > sockets on PCBs! Building a hextile around it would be the perfect
> > solution to both worlds. Both breadboard and PCB expirimenters and
> > hextile expirimenters would get what they wanted. All you'd need to do
> > to have the DIP version is trim the PCB and solder pins to it! You have
> > to admit, it's a reasonable solution!

--


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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9312 Mon, 17 Jan 2000 21:35:42 -0800 [alt-beam] Re: D1 "'beam@sgiblab.sgi.com'" Wilf Rigter

You mean:

<>

regards

wilf

> -----Original Message-----
> From: Bob Shannon [SMTP:bshannon@tiac.net]
> Sent: Monday, January 17, 2000 4:30 PM
> To: beam@sgiblab.sgi.com
> Subject: Re: D1
>
> Wilf Rigter wrote:
>
> > Hey Bob,
> >
> > What's a smart cap circuit?
> >
> > regards
> >
> > wilf
>
> The Smart Cap circuit is my solution to the D1 dilemma, I developed it for
>
> Chiu's first photovore contest to add long term behavior abilities to the
> basic
> photopopper design.
>
> I wish I had an electronic schematic, but...
>
> All this circuit uses is a NPN phototransistor, a PNP switch, and a single
>
> resistor.
>
> The NPN phototransistor is connected across the base and emitter of the
> PNP switch transistor, with the phototransistors collector going to the
> PNP's emitter. This connection is also the positive supply line.
>
> The emitter of the NPN phototransistor is connected to the base of the
> PNP, and
> also to a bias resistor to ground. For the common Radio Shack NPN
> phototransistor (2 lead type, looks like an LED) a value of 5.1 K seems to
> work
> well. Adjusting this bias resistor sets turn-on point, and adding a cap
> can control
> any hysteresis if desired (you can also play with the base lead of 3
> terminal phototransistors to get the same effect).
>
> The load connects between the PNP transistors collector and ground.
> Any load will do, so long as its within the PNP transistors abilities.
>
> The only leakage current (very low) flows while light (and energy) is
> available. I find this seems to work better than circuits with a dark
> leakage
> current (low-side NPN switch with cds photocell).
>
> In Vore-n-more, I used this circuit to dump a 1.5 F gold cap through 75
> ohms
> and into the capacitor bank of a photopopper. The 1.5 F cap was charged
> through a schottkey diode from the photovores 3733 solar cell, through a
> small set of 'floater' solar cells in series.
>
> The idea here is that the main solar cell will charge the 1.5 F cap to a
> bit
> below the photopopper's turn on point, but that does the bot no good when
> the
> lights go out. I used 1381-J triggers, so I needed the 1.5F cap to charge
> to around
> 3 volts or so to have a useful energy reserve. A pair of tiny AM-1437
> cells do this trick nicely.
>
> Another feature of this setup is that an empty 1.5 F cap will put the
> photovore to 'sleep' under a bright light, until its fed long enough to
> have a good energy reserve.
> As the supercap charges, the photovore slowly wakes and turns to the
> light, then becomes as active as usual once its full.
>
> 'Till the local light pool goes dark....
>
> Then the smart cap circuit triggers, and the PNP switch is no longer
> starved for base current. The supercap is dumped through 75 ohms into the
> photovores main
> drive caps, and the bugger takes off like a cockaroach directly towards
> the next nearest light source (there's an on-line vid of this behavior).
>
> Just adding the 1.5 F cap, floater cells, a diode and resistor, the range
> of behavior has really expanded a lot. This little photovore has long
> term behaviors and 'memory'.
>
> Its really amazing to see how well the photopoppers 'vision' system can
> operate over a huge range of illumination levels and still accurately
> track a distant light source. I mostly build CPU based bots, and getting
> the optical dynamic range that the simple popper has is not easy to do.
> But put a little energy reserve in there, and see how well a photovore can
> see in the dark!
>
>
>
>
>



Attachment: SMARTCAP.gif

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