Project Statement
Often images of structures, wildlife and seabed are required for monitoring and exploration. Divers have limited amount of oxygen in their tanks to get these pictures as well as it is often not safe to dive due to current and pollution.
Image have to be correctly oriented to be used and a remotely operated vehicle has to be positioned using a control system to attain this orientation.
Can we design and build a remotely operated vehicle that can take pictures at 1.5 meters depth?
Considerations
- Pressure of the water at the depth of 1.5 meters
- how to move the vehicle efficiently to the following
- which method of data transfer would be most provide minimal interference but at the same time most convenience.
- recovery in case of a failure.
Concept Consideration
Taking some of the above point this are the key component we decide to further brainstorm.
Therefore, we have shortlisted a few key component.
- Data Transmission
- Propulsion
- Housing
- Power Source
Ideas
After deciding on which component we would most likely be using we came up with two design.
Design 1
Design 1 has side motor that rotate which will provide the vertical and some of the horizontal propulsion. The side motor will rotate with the use of servo motors and thus helping in the vertical movement. However, this may cause the ROV to out of control due to the in balance of the propulsion may not be balance.
Design 2
For design 2 we plan to fix the motors in place, thus making it more balanced, however it may be heavier. But it will allow for a simpler and conventional design.
Function analysis
The diagram below is our detailed function analysis:
Electronics
Even the dumbest of rovers needs some form of command and control in order to move. In this post, I will detail the choices made for electrical and electronic design of our team's unmanned rover.
The brains
For the CPU of the unmanned vehicle, we've decided to use a programmable Arduino microprocessor. This microprocessor will be responsible for collecting information from the camera and sending it back to the controller, as well as receiving information from the controller to control the motors.
Power
The rover will be fed by 2 power sources:
- 9V power supply for motors
- 5V power supply for Arduino microprocessor and camera
Communications
A single cable will be used to relay both power and serial communications to and from the rover.
Motive force
We'll be using at least 4 different motors - 2 to move the rover up and down, and 2 to propel the rover forward. By varying the rotational speeds of the forward-propelling motors, we can also have the rover move left and right.
"Eyes"
It would be difficult to control the rover without being able to see where it's going. As such, there is a need for an onboard camera to show what the rover is "seeing".// todo with camera
Lists of sensor and electronics
1)Ultra bright LED - provide vision so that arduino camera can take picture clearly
2)Arduino Camera - take picture under the water
3)Arduino Uno - to control the electronic components
4)Motors - used for propellers to control the direction of vehicle
4)Motors - used for propellers to control the direction of vehicle
Lists of building materials
- PVC pipes - main body
- Acrylic - housing for the camera
- Aluminium extrusion - for the support of the ROV frame
- Foam - to make the ROV less dense
- 3D printed part (ABS/PLA) -motor housing and propeller
- Ethernet cable
The post has a good beginning with listing out your considerations but it would have been great if you put it in a form of a story rather than listing points.
ReplyDeleteYou have considered options of wireless communication underwater. If you had done a bit of research, wireless communication that you referring to such WiFi and Bluetooth doesn’t work. Only acoustics works which is a very expensive system. Hence you don’t really have any choices but have a wired connection aka tether.
The position of your camera seems to be horizontal facing and I was wondering what would you like to take pictures off? If it is the seabed, a better option is at the bottom rather than tilting the vehicle. If it is submerged structures like oil rigs, or ships then your current position would be ideal. This could scope your project. Also for your demo, you may want to decide where your artefact will be.
A block diagram for the electronics and the system would be easier for the reader to visualize before you went into the details. You didn’t mention how you will be manoeuvring the vehicle. Joystick, simple toggle switches or perhaps telepathy :D.
Do remember to list out any references while you did your research. I should also commend you on the length of the post. It is not very long and keeps your users focused. Looking forward to taking pictures underwater!
Hi Group 2, I can see the team spent quite some time to think about how the ROV should look like.
ReplyDeleteFor the next step, I would suggest that for every block of the Functional Analysis, you should list down one or two candidate real-world model of components or items, along with some written justification why you think that particular real-world item is suitable to do its job (eg. 'Arduino Camera' -> OV7670 camera module -> Because it has sufficient view angle, been used in other ROVs before (give examples), power drain is acceptable, etc. etc.).
The reason is, you cannot start your actual mechanical design yet without knowing the dimensions and mounting method of the critical components. The PVC pipe or aluminium extrusion frame and 3D printed casings merely 'wrap around' those critical parts. By mechanical design, you are expected to draw out a 3D assembly in Inventor or similar CAD software.