The first solution is rather simple in nature. The structure is made up of 1” PVC piping. There are two propellers placed internally in the rear of the structure to propell the ROV forward. These also function to steer the ROV to the left or right without using a rudder system. Centered externally on each side of the structure, is a propeller facing up and down. These will aid in the surfacing and submerging of the ROV. The propellers will be those used on the previous year’s ROV.
This solution seems very pratical. The resources necessary are easily available to me and my teammates. Also, the design should be able to perform all the tasks necessary to complete the competition requirements. I like how the inside of the structure is left open to include the robotic arm, lights, video cameras, and anything else necessary for the ROV.
Pros
- The PVC structure will be postively buoyant which is good because it is easier to add weight for buoyancy than to take away weight.
- Able to surface and submerge without needing to move forward.
- Two upward propellers will keep ROV balanced during ascent or decent
Cons
- Requires a lot of power to steer the ROV.
- Taking turns slows the ROV due to opposing motion of one propeller.
- Structure may be too positively buoyant.
The second solution is very similar to the first. The structure is also constructed of 1” PVC piping. The structure resembles the skeletal nature of a rectangular prism. Two propellers are used to ascend and descend the underwater ROV. One is located in the bow of the ROV, and the other is located on the stern to ensure that the ROV does not lean back or forth during surfacing. The two propellers located externally on the stern of the ROV are used to propell the ROV forward and rearward. These propellers also function to turn the ROV left and right.
This solution is also very practical to make. It requires the same resources as the first solution. Also, there is no major expertise in certain tools or materials necessary for this design. The only concern I have about this design is that the propeller placed in the front may interfere with the robotic arm, which is also placed in the front of the ROV.
Pros
- Capable to ascend and descend without needing to move forward
- Is light weight and will not require a lot of power to move
- PVC structure will be positively buoyant
Cons
- Requires a lot of power to turn the ROV left and right
- Little space in front for robotic arm, lights, and video cameras
- Turning cause the ROV to slow down
The third design is the most complex of the three. This design can be most easily compared to an airplane. On the top are two wings extending over the side. These would be made out of some kind of plastic, such as plexiglass. Under each wing is a propeller to move the ROV back and forth. At the rear of each with is a diving place. These curve up to make the ROV surface and curve down to make it submerge. All the way in the rear of the design is a rudder. This is placed in between the propellers to move the ROV left and right. The bottom is a PVC box which will contain the robotic arm, video cameras, etc.
This solution is rather complex and would be quite difficult to produce. By using the diving planes, the ROV is forced to move forward during surfacing and submerging. Also, since the ROV is so complex then there are more potential problems that I will run into during the production. If something were to happen with the rudder, then the propellers can act as the steering if necessary.
Pros
- Can surface and submerge while moving forward.
- Has less propellers so it uses less power
Cons
- More complex means more problems
- Is heavy and may be negatively buoyant
- Cannot surface when stationary
After looking over the pros and cons of each design, I decided that the first solution seems to be the most practical. However, i felt there was not enough torque to turn the ROV left and right. So i decided to do a combination of the first and second design. The final solution will be the first design, only with the rear propellers located outside the ROV rather than inside
The third design is the most complex of the three. This design can be most easily compared to an airplane. On the top are two wings extending over the side. These would be made out of some kind of plastic, such as plexiglass. Under each wing is a propeller to move the ROV back and forth. At the rear of each with is a diving place. These curve up to make the ROV surface and curve down to make it submerge. All the way in the rear of the design is a rudder. This is placed in between the propellers to move the ROV left and right. The bottom is a PVC box which will contain the robotic arm, video cameras, etc.