Alt-BEAM Archive
Message #05310
To: beam@sgiblab.sgi.com
From: David Perry davidperry@geocities.com
Date: Mon, 19 Jul 1999 09:59:21 -0400
Subject: Re: MPNC was AUTOMATIC PNC
> damn it why is it so quiet!!!!!!!
> i can't see how that would work, you'd need to apply ground to each of the
> switches. oh come on, please help, are you trying to sobotage my robot
> building or what? :-)
>
> David Perry
>
> -----Original Message-----
> From: James Wilson
> To: beam@sgiblab.sgi.com
> Date: Monday, 19 July 1999 6:37
> Subject: Re: MPNC was AUTOMATIC PNC
>
>
> >Have you thought about an exclusive or gate? or an or gate? I think it
is
> >possible to make the gate you want by using inverters and a voltage
> detector
> >(things the beamer may already have in his bag of tricks)
> >
> >James :-))
> >----- Original Message -----
> >From: David Perry
> >To:
> >Sent: Saturday, July 17, 1999 1:11 PM
> >Subject: Re: MPNC was AUTOMATIC PNC
> >
> >
> >> holy crap! you have revolutionised the microcore!!!!!!!!!
> >> It will be the end of the traditional microcore and PNC as we know
it!!!!
> >> damn, to late to implement into my caterpillerBot.
> >>
> >> One question while i'm at it, i am using 2x 74hc240 to reverse my new
> bot,
> >> but it has 4 reverse switches when i only want one. is it safe to hook
> >them
> >> all up ?
> >>
> >> David Perry
> >>
> >>
> >> -----Original Message-----
> >> From: Sean Rigter
> >> To: BEAM
> >> Date: Sunday, 18 July 1999 4:44
> >> Subject: MPNC was AUTOMATIC PNC
> >>
> >>
> >> >Hello group,
> >> >
> >> >Nudged by Bruce Robinson,
> >> >
> >> >>But, umm, tell me. How would your circuit look for a 6-Nv microcore?
> >> >.
> >> >
> >> >here is an short article describing an improved PNC circuit with
> >> >examples for 4 and 6 Nv cores. Also included is an introduction to
MPIC
> >> >pulse injection controlled gait changes. The latter is an untested
> >> >experimental design and there is much detail to be worked out. Feel
> >> >free to build it and report back to BEAM land.
> >> >
> >> >enjoy
> >> >
> >> >wilf
> >> >
> >> >
> >> >
> >> > MPNC Nvcores - a logical solution for saturation
problems
> >> > using the multiple pulse neutralizing circuit
> >> > wilf rigter - 07/99
> >> >
> >> >In a conventional microcore design the dreaded twin process saturation
> >> >problem is addressed with a Nu based pulse neutralizing circuit (PNC)
> >> >which absorbs all circulating processes and when it times out
initiates
> >> >a single process in the microcore. Since the PNC forces one Nv output
> >> >active low any motor connected to that Nv would be rotating possibly
> >> >mangling a pair of legs in the process. This is normally avoided by
> >> >disabling the output drivers during the time the PNC is active.
> >> >
> >> >Despite the PNC's longevity in BEAM land, all things must change as
old
> >> >PNC based ucore designs are superseded by a new generation of Nv core
> >> >designs which include a "multiple process neutralizing circuit"
(MPNC).
> >> >Unlike the PNC base ucore circuits, this new design instantly
> >> >initializes the Nvcore and does not require any motor driver inhibit.
> >> >After power up, the MPNC constantly monitors for and neutralizes
> >> >multiple processes in the core. Since the MPNC does not require an Nu
> >> >inverter, a single 74HC14 can be used for a 6Nv core.
> >> >
> >> >The MPNC design is added to a Nvcore with simple diode logic requiring
> >> >only 2 diodes for a 4Nv ucore and 4 diodes for a 6Nv hexcore.
> >> >
> >> >THE 4NvMPNC
> >> >
> >> >A 4Nv microcore uses 2 diodes to snuff out core saturation by
> >> >neutralizing multiple (twin) processes with the anodes of the diodes
> >> >connected to N1 and Nv2 outputs and the cathodes to Nv3 and Nv4 bias
> >> >points respectively. 4NvMPNC.GIF shows the schematic for a MPNC ucore
> >> >complete with a 74AC240 reverser circuit. The MPNC logic is simple:
with
> >> >two possible saturation states (NV1 AND Nv3 active or Nv2 AND Nv4
> >> >active), the 1Nv output is active low and this level connected
through
> >> >the diode to the Nv3 bias point forces the Nv3 output high,
neutralizing
> >> >the saturation process. Similarly the Nv2 output neutralizes any
> >> >potential saturation process in Nv4.
> >> >
> >> >THE 6NvMPNC
> >> >
> >> >A 6Nv MPNC hexcore requires 4 diodes compared to the 2 diode MPNC
ucore
> >> >to neutralize not only twin but also triplett multiple processes. To
> >> >instantly start the 6Nv core with a simgle process in Nv1 the diodes
are
> >> >connected as follows: The anodes of 3 diodes are connected to Nv1
output
> >> >with cathodes connected to the bias points of Nv3, Nv4 and Nv5. The
> >> >fourth diode anode is connected to Nv2 output and cathode to Nv6 bias
> >> >point. The graphic 6NvMPNC.GIF is attached showing the schematic of a
> >> >6Nv hexcore with MPNC.
> >> >
> >> >THE 6NvMPIC
> >> >
> >> >As an introduction to the more advanced concept of the Multiple
Process
> >> >Injection Circuit (MPIC) for gait control, I have included 6NVMPIC, a
> >> >draft schematic which shows how one can inject (and regenerate) an
> >> >arbitary number of processes in a 6 Nvcore. The MPIC includes the same
> >> >function as the MPNC since it must be able to inject as well as
> >> >neutralize in order to control processes. It is possible to add the
MPIC
> >> >to a conventional PNC design to initiate the gait at power up. The
MPIC
> >> >control lines can be connected to a number of sources including DIP
> >> >switch, "Collission Nu", "Turning Nu" etc but also (via a simple
> >> >infrared or radio link) to an IBM PC printer port or onboard STAMP or
> >> >PIC I/O line. The example shows a single process default HexCore with
20
> >> >second duration Nu controlled process injection circuits.
> >> >
> >> >
> >>
> >
>
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