Science 2021-2022 Design Specs

This is the science design guide in progress, high level stuff, a sketch is to be created soon after this

THIS DOCUMENT IS OUT OF DATE

Core elements

  • Hoover for dirt
  • Turn table for test tubes
  • Sensor read head
  • Rock cam read head
  • Positioning camera
  • Test tube camera

Structure Material

  • the plan is to use aluminum extrusions for the entirety of the build
  • add more detail later on of the choice of pumbing material as well as test tube size and material
  • should talk about wire management here

Expected Actuator List

All to be specc'ed out

Motor Specs (generalized)DescriptionSystem
24V Brushed DC w/ encoderLift motor for linear axisElevator (all 3)
ServoHead ToggleHoover/Sensor/Microscope
ServoHead ToggleSensor/Microscope
24V Brushed DC w/ encoderLift motor for linear axisSensor read head
24V Brushed DC w/ encoderLift motor for linear axisRock Camera
24V Brushed DC w/ encoderTurn table rotary motorTurn table
ServoTest tube lifterTurn table
24V Brushed DC (powerful)Vacuum motorHoover
24V Brushed DCDrill motorHoover

Expected Camera List

All to be specc'ed out

Camera Specs (generalized)Description

System

USB Dino camera with light and zoom (AM3111 - ordered)to look at rock structureRock Camera
USB Simple color capable webcamto see colours of chemical testsTest tube Camera
USB Simple webcamto see where the sensors in relation to ground

Positioning Camera

Expected Sensor List

SensorDescriptionSystem
Methane Sensor (683)https://www.dfrobot.com/product-683.htmlSensor read head

Humidity & Temperature sensor (385)

https://www.adafruit.com/product/385Sensor read head

Soil Moisture sensor (599)

https://www.dfrobot.com/product-599.html

Sensor read head

Integrated incremental encoder (TBD)From polulu motorElevator
Various magnetic switcheshttps://www.dfrobot.com/product-2025.htmlEverywhere (replaces limit switches)

Detailed System Descriptions

Hoover

  • this will be used to transport dirt to the test tubes
  • will go up and down on a vertical axis to reach the ground
  • should incorporate adjustable vent holes to control air dirt ratio
  • delivery end shall use a cup separator
    • design for various mesh sizes to test with
  • deliver to 3 test tubes simultaneously
  • use some sort of suction motor to generate the vacuum → 24V
  • potentially add a drill motor
    • (lathe style power with hex shaft to fix motor to frame rather than on axis)
  • 1 linear axis up and down
    • plumbing might be tricky

Turn table

  • stores 3 test tubes per station with 5 total stations, layout will place the 15 test tubes in 3 rings of 5 concentric
  • test tubes need to follow no spill policy
    • use gasket and bellows to seal by pushing it
  • need to figure out how to make good air tight fit with delivery system
  • needs to rotate using a standard continuous motion (no Geneva drive)
  • may need another axis to  properly locate the test tubes under the vacuum delivery
  • size of test tube tbd

Sensor read head

Rock Camera

  • some sort of dino camera will be used
    • if one is found in the bay, it will be used
  • 1 linear axis up and down
    • x-z positioning might be difficult, this is addressed in the nice-to-haves section

Positioning Camera

  • static camera on chassis to see the the dirt in relation to the instruments
  • can be a cheapo webcam found in the bay

Test tube Camera

  • static camera on chassis to see the test results from the test tubes
  • can be a cheapo webcam found in the bay

Nices-to-haves

  • 1 axis side to side gantry
    • this will help strafing positioning that would be difficult to do with just the drivetrain
    • the entire science mechanism will go on the gantry and the gantry mounts on the chassis
  • 2 axis x-z gantry
    • replaces the 1 axis gantry
    • would really help with positioning of read heads
  • Drill with hoover
    • that extra spicy touch
  • Other sensors
    • if budget permits, we could get a CO2 sensor,
    • spectroscopy will have to wait till next year (big grin)
  • aiming diode
    • laser pointer to see where the linear axis will end up