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THIS DOCUMENT IS OUT OF DATE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) | Description | System |
---|---|---|
24V Brushed DC w/ encoder | Lift motor for linear axis | Elevator (all 3) |
Servo | Head Toggle | Hoover/Sensor/Microscope |
Servo | Head Toggle | Sensor/Microscope |
24V Brushed DC w/ encoder | Turn table rotary motor | Turn table |
Servo | Test tube lifter | Turn table |
24V Brushed DC (powerful) | Vacuum motor | Hoover |
24V Brushed DC | Drill motor | Hoover |
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 structure | Rock Camera |
USB Simple color capable webcam | to see colours of chemical tests | Test tube Camera |
USB Simple webcam | to see where the sensors in relation to ground | Positioning Camera |
Expected Sensor List
Sensor | Description | System |
---|---|---|
Methane Sensor (683) | https://www.dfrobot.com/product-683.html | Sensor read head |
Humidity & Temperature sensor (385) | https://www.adafruit.com/product/385 | Sensor read head |
Soil Moisture sensor (599) | https://www.dfrobot.com/product-599.html | Sensor read head |
Integrated incremental encoder (TBD) | From polulu motor | Elevator |
Various magnetic switches | https://www.dfrobot.com/product-2025.html | Everywhere (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
- allows the sensors to be placed in the dirt, as well retract to get a base line reading
- read head will have the following sensors:
- Methane sensor (683) https://www.dfrobot.com/product-683.html
- Humidity & Temperature sensor (385) https://www.adafruit.com/product/385
- Soil Moisture sensor (599) https://www.dfrobot.com/product-599.html
- mind the wiring management
- 1 linear axis up and down
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
- aiming diode
- laser pointer to see where the linear axis will end up