Robotics Intensive

From Artisan's Asylum

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(Vending Machine Electrical Design)
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Home Base:
Home Base:
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* To the right of the door leading to the [[Kitchen]].
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* To the right of the door leading to the Kitchen.
=====Modes of Operation=====
=====Modes of Operation=====
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32" W x 12.5" D x 12" H
32" W x 12.5" D x 12" H
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==== Vending Machine Electrical Design ====
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[https://docs.google.com/file/d/0B7UV3cY172QHWXZzcVNLd1BwMjA/edit Downloadable PowerPoint Electrical Schematic with Excel parts list embedded (From Google Docs select File -> Download) ]
===Robotic Vacuum Cleaner===
===Robotic Vacuum Cleaner===
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===Electrical Design===
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====Vacuum Electrical Design====
[https://www.circuitlab.com/circuit/qsyk47/robotics-intensive-vacuum-overview/ Power Schematic]
[https://www.circuitlab.com/circuit/qsyk47/robotics-intensive-vacuum-overview/ Power Schematic]
[https://www.circuitlab.com/circuit/d42awa/current-sensor-circuit/ Current Sensing Schematic]
[https://www.circuitlab.com/circuit/d42awa/current-sensor-circuit/ Current Sensing Schematic]
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== Vending Machine Electrical Design ==
 
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[https://docs.google.com/file/d/0B7UV3cY172QHWXZzcVNLd1BwMjA/edit Downloadable PowerPoint Electrical Schematic with Excel BOM embedded]
 
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--[[User:Mike g watson|Mike g watson]] 10:37, 4 June 2012 (EDT)
 
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[https://docs.google.com/presentation/d/1I24UeY0ss1J-RB1a7nYvwTxiqPQLz2PKTWkNISkxXmw/ Electrical Schematic]
 
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--[[User:Mike g watson|Mike g watson]] 10:37, 4 June 2012 (EDT)
 
===Google Documents===
===Google Documents===

Current revision as of 14:43, 11 January 2016

This is the main discussion, coordination, and documentation page for the Robotics Intensive class at Artisan's Asylum.

NOTE: If you're unfamiliar with wiki editing and formatting, please check out this page: MediaWiki Formatting. You will need to be logged in to edit this page, and once you're logged in you'll see an 'edit' button as one of the top tab options.

Contents

Class Presentations

These are the powerpoint presentations from each class:

  • Introductory Presentation - An introduction to the instructor, to the Asylum, to types of robotic design, descriptions of the two projects, and course goals and plans
  • Session 2 - Introduction to the programming and controls project
  • Session 3 - Review of the programming and controls project, brief description and introduction to PID control
  • Session 4 - Breaking up into teams and top level conceptual design introduction
  • Session 5 - Decision matrices and task worksheets
  • Session 6 - Electric motor theory, motor selection, preliminary design reviews

These are the handouts from class:

mbed/m3pi Robot Resources

We used an mbed processor controlling an m3pi line following robot platform for the programming and controls project at the start of class. You can find resources for it in this section.

  • You can purchase an m3pi robot here. We used an mbed NXP LPC1768 development board to control the m3pi platform, which you can find available for purchase here.
  • The mbed Handbook contains a lot of useful information about programming the platform.
  • The mbed Cookbook contains a lot of sample programs that use the mbed platform to accomplish specific goals
  • The m3pi homepage contains a lot of information about getting up and running on the m3pi platform, including a simple and easy to follow Hello World application.
  • The online compiler is where the programming work for the mbed is done. Email Gui for login and password information for the class account.

Robot Discussion Section

This section is for the group discussion and online documentation of information pertaining to our two main robot projects.

Robot Vending Machine

Information and discussion goes here!

Top-level Requirements

Operating Environment

Network of lines to be followed:

  • Linear Distance: 1111 ft

Corridor/Path:

  • Min Width: 44 (52) in
  • Max Width: 84 in

Home Base:

  • To the right of the door leading to the Kitchen.
Modes of Operation
  • Vend
    • Stop on demand
    • Perform transaction with customer
    • At end of transaction, generate audible tone. Customer may extend transaction period.
    • Robot begins to move at end of transaction.
  • Move
    • Follow network of lines
    • Speed: 1.5 ft/s nom, 3.0 ft/s max
    • Stopping Distance: 1 in nom, 3 in max
    • Forward, Reverse, Turn
    • Emergency Stop button(s) accessible by humans approaching from any side
  • Avoid Obstacles
    • Avoid obstacles
    • Generate noise/alert
  • Charge
    • For now, robot will be plugged into wall socket manually.
Mission Profile
  • 8 - 12 pm: Stationary vending.
  • 12 - 8 pm: One cycle around network of lines every two hours.
    • Six stops at predetermined locations. Remain at each location for five minutes.
    • Estimate three or four unscheduled stops requested by customers to vend.
  • 8 pm - 8 am: Stationary vending.
Health Monitoring
  • Do not leave home base unless system health is acceptable
    • State of charge of batteries is acceptable
    • Zero fault conditions detected, or detected faults may be accommodated acceptably
Weight
  • Vending Machine, Empty: 400 lbf
  • Snacks: 100 lbf
  • Change: 50 lbf
  • Motors, Batteries, Etc., Etc.: 200 lbf
  • Margin: 50 lbf
Size
  • Size of robot is size of vending machine plus 6 - 8 in on each vertical side and plus 18 in height to accommodate wheels, motors, chassis, batteries, etc.

Subsystem Discussion

Vending Machine Information

The manual for the vending machine can be found here

  • Weight: 376.5 lbf
  • Height: 72 1/8 in
  • Width: 32 3/4 in
  • Depth: 28 in

Available interior space

25" W x 14" D x 12" H

OR

32" W x 12.5" D x 12" H

Vending Machine Electrical Design

Downloadable PowerPoint Electrical Schematic with Excel parts list embedded (From Google Docs select File -> Download)

Robotic Vacuum Cleaner

1. Create a representative mission profile for your robot.

Robot is plugged in overnight. Staff member unplugs and turns on in the morning.

Robot navigates at ~1 mph pace, covering every linear foot of the space 2x, following line laid down for vending machine.

Robot navigates ~10 minutes before encountering an obstacle it cannot pass without losing track of the line and begins beeping.

Staff member

Approx e

Total mission time is 50 minutes and robot returns to docking location.

A staff member notices after 30 minutes and plugs it in.

Robot is used 3 hours later to clean woodshop manually (see nice-to-have section).


2. Estimate your robot's maximum size and weight.

250 lbs (steel frame + DC motors + 65 lb battery + ...)

Approx 36 inch width, roughly circular shape.


3. Decide on 2-3 nice-to-have features you want to include in your design.

Can be used in "manual mode" to clean other spaces.

Looks "friendly". See [1] for inspiration

Can be used as a "cleaning pod" to clean individual spaces.

Can be called remotely and delivers itself to requester's space.


Quick notes:

This industrial sweeper is about the right size and, by relying on brooms augmented by a small vacuum, makes do with only 290W of motor (counting the main traction motor, the side brush motor, and the 50W--0.07 hp--vacuum motor. It can propel itself and is claimed to run for 3 hours on a single, 12V 100Ah gel battery: brochure with some specs: [2] promotional video: [3] --Richard

Jade found [4] which might be an option to prevent building sweeper components from scratch.


Mechanical conceptual design

At 1 mph (0.45 m/s) we estimate rolling resistance of 22 N and resistance from the main brush of 45 N (this is a very rough guesstimate based on pushing a broom and comparing the feel to holding up a 13 lb weight)

This corresponds to 30 W, before incorporating a fudge/safety factor.

This is consistent with the 200W rating of the Advance 28B main traction+brush motor, accounting for a fudge factor and 2.5x higher speed of the Advance 28B. However we would make this motor at least 100W to have a safety factor.

Using the Advance as a guide, we would also budget 40W for a side brush motor and 50W for a vacuum motor.

Therefore, we budget 200W-300W for the main motor(s).

Note: It may be a good idea to spec drive motors that are sufficient to drive the robot, and let the brush motor contribute to forward motion as well. (This way if the brush friction is greater than expected, the problem can be solved by increasing the brush motor power.)

We expect to require 5 or more distinct motors: 2 drive motors for differential drive; a main brush motor; a small vacuum motor; and possibly side brush motor.


Vacuum Electrical Design

Power Schematic

Current Sensing Schematic

Google Documents

Parts List

Resources

Robot Marketplace

Great info on sprocket and chain drives. Explains pitch, chain size, etc

Possible source for sprockets and wheels

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