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A DIFFERENT CONCEPT IN ROBOT CONTROLLERS
Walking Machine Control Computers
---- gait control of robotic walkers, and behavioral control of
servo-powered robots + animatronic devices ----
ORDER INFO

- CUSTOMER FEEDBACK -
"... After I became familiar with your WMC it's been a pleasure experimenting with different gaits. Makes life much more simple than driving all (12) of those servos from my [..other..] board ..." - R.E., Minneapolis, MN
WMC12-ASY - 12-Servo Walking Machine Controller - assembled+tested, $62.95.
WMC12-KIT - 12-Servo Walking Machine Controller - kit-form, $48.95.
WMC20-ASY - 20-Servo Walking Machine Controller - assembled+tested, $76.95.
WMC20-KIT - 20-Servo Walking Machine Controller - kit-form, $60.95.

BOTCOP-WMC-ASY - Dual-Processor Walking Machine Controller - assembled+tested, $68.95.
BOTCOP-WMC-KIT - Dual-Processor Walking Machine Controller - kit-form, $54.95.
[Note - Stamp module not-included with the BOTCOP-WMC boards].


The OricomTech Walking Machine Control Computers are designed specifically for control of walking machines, animatronics devices, and servo-driven robots. They are complete behavioral control systems, with gait generation, storage, and scheduling capability. They can generate gaits for walkers involving up to 20 R/C servos.

  • Servo sequences are setup as tables of movements, with no computer language programming required.
  • The controllers also have sensor alarm capability.

    WMC General Features

  • works as a regular slave servo controller under direct host control, and/or as a standalone behavioral controller
  • controls up to 20 R/C-type servos
  • pulse resolutions to 1-usec (4-usec in CPG mode)
  • 255 ramping velocities
  • all servos refreshed within 20-msec
  • control up to 20 digital I/O lines
  • sample up to 8 A/D channels
  • behavior store in 32 KByte eeprom
  • RS-232 comms at 1200 - 38400 bps (will operate
    at higher baudrates with some limitations)

    Applications

  • robotic walkers
  • robotic arms
  • animatronics
  • servo-powered wheeled robots
  • general servo control
  • WMC12 - 12-Servo Walking Machine Controller is a small, credit-card sized board that handles:
  • up to 12 servos
  • up to 5 analog alarm channels
  • up to 4 digital alarm channels
  • up to 12 digital I/O channels
  • 3.5" x 2.15" (89 x 55 mm)

    See below for more (details)

  • WMC-12 Blow-Up
    [WMC-12]
    WMC20 - 20-Servo Walking Machine Controller handles:
  • up to 20 servos
  • up to 8 analog alarm channels
  • up to 4 digital alarm channels
  • up to 20 digital I/O channels
  • 3.6" x 3.0" (91 x 76 mm)

    See below for more (details)

  • WMC-20 Blow-Up
    [WMC-20]
    [ NEWEST PRODUCT ]
    BOTCOP-WMC - Dual-Processor Walking Machine Controller
  • board mounts both a WMC12 Walking Machine Chip, plus a Basic Stamp 2 or similar 24-pin module
  • WMC12 chip handles up to 12 R/C servos, up to 5 analog alarm channels, and up to 4 digital alarm channels
  • 24-pin module serves as a local host processor to control the WMC chip, and also provides "general programmability"
  • 24-pin module can control up to 8 additional servos
  • handles up to 20 servos, up to 5 A/D channels, and up to 26 digital I/O lines total
  • 3.3" x 2.8" (85 x 71 mm)
  • See next page for
    BOTCOP-WMC Details
    [to BOTCOP-WMC page]

    TEST ROBOTS - shown at the right are 3 robots used to test the Walking Machine Controllers. All robots used WMC controllers operating in standalone state-machine mode (as described later). Individual pages can be consulted for more details on each robot.

  • Nico-II is a quadruped walker, which uses 8 R/C servos plus a 2-channel IR proximity detector for obstacle detection, and has about 20 gaits and other behaviors.
  • Gimlee-U8 is an octopod walker with 16 R/C servos, and a basic walking gait.
  • E-Ger is a 2-servo differentially-steered mini-sumo base with 4 IR proximity detector channels for front and rear obstacle detection, plus 4 IR photoreflectors mounted on the corners to detect drop-offs. E-Ger was designed to run around a table top, and not fall off the edges.
  • * WMC12 Test Robot *
    Nico-II - Quadruped

    [Nico-II]
    * WMC20 Test Robot *
    Gimlee the Octopod

    [Gimlee]
    * WMC12 Test Robot *
    E-Ger the Mini-Sumo

    [E-Ger]


    TECHNICAL OPERATION

    Walking Control Basic Features

  • CPG (central pattern generator) control of servo trajectories.
  • up to 126 separate behaviors with up to 44 individual servo movements in each.
  • each behavioral table sequence can be up to 40 seconds in duration, and repeated from 1 to 255 times (or indefinitely).

    Walking Control Advanced Features

  • for semi-autonomous or standalone operation, the WMC can be configured for FSM (finite-state machine) operation, as follows ....
  • complex movement sequences are created by linking successive behavioral tables.
  • event-driven behavioral changes are initiated by external trigger / alarm signals.
  • up to 12 analog & digital trigger / alarm channels.
  • low battery voltage shutdown.

    The Walking Machine Controller can function at 3 different levels:

    Level 1 - standard slave servo controller under control of a host processor, such as PC, OOPic, Basic Stamp or Atom, via RS-232 link. In this mode, the host cpu calculates all positions for each each servo, but high-precision servo pulse-generation operations are off-loaded to the WMC. This mode requires on-going intensive computation by the host cpu, as with all standard servo controllers.

    Level 2 - pattern-generator / gait controller. Also under control of a host cpu, but where the WMC completely controls trajectory generation and coordination of all servo activities. This mode removes all gait generation and timing operations from the host cpu, which is free to perform sensor integration and high-level decision making. Eg, the host signals the WMC to initate "walk-forward" by sending nothing more than a short command (such as "EX02"), and the WMC then controls the gait in entirety. Of course, the user still has the fun of designing the gaits the WMC will generate - more on this below.

    Level 3 - autonomous standalone operation. Here, the WMC is configured as a finite-state machine (FSM), and both controls all servo movements and gait-generation sequences, as well as performing its own sensor checking and decision-making. Eg, real-time external events (such as bumping into a wall) can initiate entire sequences of linked-behaviors, such as stop, back-up, turn away, and resume forward-walking. In this mode, complex behavioral sequences can be produced by the WMC without a host cpu even being present.

    Learning Curve and Progression. Levels 1 through 3 represent a progression of increasingly sophisticated possibilities, away from host control and into autonomous operation. These also form a convenient learning curve progression, where the WMC can initially be used as a standard slave servo controller, but then more and more activities moved from the host cpu to the WMC as time goes on. One or two gaits can be built up initially, and these added to later on. Also, once gaits are established, then sensor activities can be included. The WMC system is devised around the concept of modular and iterative development.

    Note that the WMC can actually operate on all 3 levels simultaneously. The host cpu can still send commands to directly control some servos in real-time (such as to pan a servo-mounted sensor), while the other servos are engaged in automated gait generation, etc. The host can also monitor WMC activity and intervene to re-direct behaviors, as desired.

    Behavioral Programming

  • no computer language programming is required.
  • CPG sequences are set up as tables of individual servo movements and other I/O.
  • command interpreter allows interactive editing of behavior tables while behaviors execute in real-time at normal speed.
  • no drawn-out edit, compile, download, test cycles - editing changes immediately take effect - building + testing behaviors goes quickly.
  • behavior tables are stored in eeprom, and executed either by linking together successive tables (autonomous mode), and/or called in directly by a host processor (slave mode).
  • simple ASCII commands - view command set.
  • at present, behavioral programming requires use of a standard terminal emulator and knowledge of hex numbers.

    Theory

  • basic WMC operation involves a table of servo movements (ie, a "behavioral state"), a scheduler for timing the movements, and an alarm structure which allows real-time external events to select state changes.
  • see the next page regards WMC Theory of Operation.
  • see the E-Ger Mini-Sumo page for a State Machine Diagram illustrating the WMC in practice.
  • RS232 Interfacing

  • note that all three WMC controllers use RS232 interfacing for communications between a host computer (when used) and the WMC chip.
  • in the case of the BOTCOP-WMC board, there is a local RS232 buss on the pcb which directly connects the WMC chip to the Basic Stamp module, which can be generally programmed for custom control. We have used this interface at up to 38,400 bps between the BS2 module and WMC chip.
  • in the case of the WMC12 and WMC20 boards, the normal connection between host and WMC is via standard RS232 levels (+/-5 to +/-12v).
  • however, it is also easy to configure the WMC20 board for direct 0-5v logic-level interfacing to a host computer. See next page for WMC20 logic-level RS232 interfacing

  • <| Controller Details
    WMC12 - 12-Servo Walking Machine Controller
  • up to 17 I/O lines total (servos + I/O + alarms)
  • up to 12 R/C servos
  • up to 12 digital I/O lines (trade off with servos)
  • up to 9 trigger-alarm inputs
  • --- 5 alarm channels accept analog or digital input
  • --- 4 alarm channels are digital only, and trade off with servos
  • 32 Kbyte eeprom for behavior store
  • 3.5" x 2.15" (89 x 55 mm)
  • WMC20 - 20-Servo Walking Machine Controller
  • up to 28 I/O lines total (servos + I/O + alarms)
  • up to 20 R/C servos
  • up to 20 digital I/O lines (trade off with servos)
  • up to 12 trigger-alarm inputs
  • --- 8 alarm channels accept analog or digital input
  • --- 4 alarm channels are digital only, and trade off with servos
  • 32 Kbyte eeprom for behavior store
  • MAX232 serial port
  • 3.6" x 3.0" (91 x 76 mm)
  • miscellaneous
  • prototyping area for custom sensor interfacing
  • low-dropout 5V, 1-Amp voltage regulator
  • extra filtering on servo power buss
  • uses SBOT28 pcb as platform
  • miscellaneous
  • prototyping area for custom sensor interfacing
  • low-dropout 5V, 1-Amp voltage regulator
  • extra filtering on servo power buss
  • uses BOT40-II pcb as platform
  • will interface either +/-12v or 0-5v logic-level RS232 devices (see section above)
  • kit-form includes about 50 parts total
  • basic construction time - under 1 hour
  • requires good soldering skills

    customer-supplied parts

  • custom components for proto area
  • RS-232 cable
  • kit-form includes about 65 parts total
  • basic construction time - about 1+ hour
  • requires good soldering skills

    customer-supplied parts

  • custom components for proto area
  • 5-Amp voltage regulator, if required
  • RS-232 cable (std DB09 modem cable)
  • Consult the SBOT28 and BOT40-II pages for technical details.

    <| TOP


    © Oricom Technologies, updated Sept 2006