Skip to main content

Home/ Robotics/ Group items tagged bottom-up

Rss Feed Group items tagged

Filter: All | Bookmarks | Topics Simple Middle
York Jong

BEAM Pieces -- Integrated circuits - 0 views

library.solarbotics.net/...parts_elect_ic.html

5star beam collection electronics ic motor robot solar survey

shared by York Jong on 27 May 07 - Cached
  • 1381s are CMOS voltage-controlled triggers -- these "gate" a source until the voltage is above some "trip" limit, at which point it is allowed onto a third pin
  • We use them as 3- or 5-volt triggers
  • This chip is often considered the heart of Nv net technology
  • ...22 more annotations...
  • The '240 is often called "the bicore chip," because we can take advantage of the 240's inverters to turn a single 74*240 into a bicore
  • The '240 also has tri-state outputs, so an enable line can be used to turn its outputs on and off simply (good for adding reversing capability to a 'bot).
  • any *cores built with a 74*04 will require additional logic "downstream" to amplify the current to levels sufficient to drive a moto
  • Schmitt triggers can't easily be used in suspended bicore implementations
  • use its buffers as little current amplifiers
  • it is usable for either grounded or suspended bicore designs (but better for suspended)
  • 74HC/HCTxx non-buffers (74HC14 or 74HC04) draw about half of the current consumption, and have about half the drive current compared to HC / HCT buffer chips (74HC240 or 74HC245). Non-buffer chips are thus better for oscillators, say Nv and Nu applications; they are not suited for use in driving motors.
  • 74AC is best suited for motor driver applications with all inputs driven rail to rail.
  • The '245 is an octal buffer chip, and so has 8 channels of buffering power available for our misuse. This chip was designed for data transmission uses, but we'll misuse it as a motor driver chip
  • The '244 provides us with 8 (thus the "octal") buffers, enableable in banks of 4. This is a very useful chip for amplifying small currents
  • it can drive up to 4 motors in 2 directions each, or you can "buddy up" inputs and outputs to drive fewer motors at higher current
  • it can drive up to 4 motors in 2 directions each, or you can "buddy up" inputs and outputs to drive fewer motors at higher current
  • If you can't find 1381s locally, you might have better luck finding its European cousin, the TC-54 -- for details on it
  • Note that if you need more than about 200 mA per motor, you'll need to use an H-bridge, or some similar motor driver
  • The ideal BEAM circuit would use a low (2V-3V) voltage core and sensors combined with level shifting high (5-6V) volt motor drivers to maximize efficiency.
  • 74ACxxx used in typical BEAM applications uses 4x more supply current than does 74HC/HCTxxx.
  • York Jong on 27 May 07
     
    The following material is intended to cover usage and part selection details of ICs you're most likely to see in BEAM robots.
York Jong

74*240-based photopopper circuits - 0 views

library.solarbotics.net/...bot_popper_240.html

5star 74x240 beam circuit electronics maxibug photopopper phototrope robot

shared by York Jong on 27 May 07 - Cached
  • This adapted photodiode is not as sensitive as large area types so C2 may need to be reduced to 0.01uF while the value of R2 and R3 can be increased by a factor of 10.
  • Two leaded phototransistors can also be used but may require extra shielding to reduce light current in the bridge to acceptable levels
  • basic photopopper functions plus reverse -- all on a single chip
  • ...8 more annotations...
  • The monocore capacitor is for positive feedback for fast switching between the two motors and to slow down and avoid high frequency oscillations.
  • R2 together with C2 limits the maximum frequency of the monocore and motor drivers when the light is bright and the sensors are equally lit
  • R3 together with C2 sets the minimum frequency of the waggle even in the complete dark which is more interesting than twirling endlessly in a circle.
  • Having said that, maxibug is not perfect: it churns its wheels while feeding and does not back out of the feeding station when full. CD MaxiBug v5 uses just a few more parts but has powerful and efficient motor drivers, its motors are off while feeding, and it backs up when full.
  • The CD Maxibug v5 uses just one 74AC240 chip
York Jong

74*14-based photopopper circuits - 0 views

library.solarbotics.net/...bot_popper_14.html

5star 74x14 beam circuit electronics maxibug photopopper phototrope robot

shared by York Jong on 27 May 07 - Cached
  • Droidmakr (Cliff Boerema) came up with an interesting idea for a light-tracking head with a form of peripheral vision. As often happens, the circuit turned into something different -- a photopopper:
  • All done with a single 74HC14 (the '240 being a motor driver).
  • I tried the same setup with the 74*240 (with an extra inverter per motor) and 7404, but the 74HC14 seems to work best.
  • ...6 more annotations...
  • John-Isaac Mumford started off by simplifying the Maxibug design, and wound up with an entirely new circuit -- Mazibug
  • The tactiles switches behave even more strongly: if a switch is closed then the bot turns away unconditionally. If both switches are closed the robots reverse straight back regardless of light level.
  • When the robot bumps into something on one side, it over-rides all the photodiode circuits and reverses the motor on the OPPOSITE side
  • From the title it would appear that all 4 photodiodes face forward but the 2 inner PDs face directly forward and the outer 2 are angled to the left and right
    • York Jong
      York Jong on 03 Jun 07
       
      behavior-based control that all done with a sigle 74HC14
York Jong

開版 - 21 views

作者: ykjiang (Amorphous) 看板: Robotics 標題: 開版 :) 時間: Thu Oct 26 00:19:17 2006 我數學雖不好，卻有理論傾向；開版第一篇，容我囉唆囉唆： 原本這裡想命名為 Behavior-based Robot 的，但覺得太侷限； 取作 Bottom Up AI ，嫌它太抽象； 喚作 Brooks' and Tilden's and...

beam behavior-based bottom-up brooks jones tilden

started by York Jong on 28 May 07 no follow-up yet
York Jong

移動機器人和工業機器人 - 29 views

作者: ykjiang (York) 看板: Robotics 標題: 移動機器人和工業機器人 時間: Fri Nov 3 01:31:02 2006 自主移動機器人（Autonomous Mobile Robot），其 中的自主（Autonomous），是為了強調機器人是自己 到處跑的，而不是被人攜帶著才移動的機器人模型 :P 在不造成混淆的場合，自主移動機器人也簡稱移動機器 人（M...

autonomous bottom-up mobile top-down

started by York Jong on 28 May 07 no follow-up yet
1 - 5 of 5
Showing 20▼ items per page