Project Overview and Proposal

Problem Overview


Remote controlled submersible robots can take several live readings and samples of water quality with waterproof sensors. Certain designs are outdated and inefficient, so better robot designs must be made. The robot should be capable of propulsion and navigation in streams, estuaries, and rivers.

The group has to design and build a robot that is able to handle the addition of sensors by another group.


Design Constraints

There is a limited amount of material for building and battery power for controlling the Sea Perch in the kit.  The building materials within the kit include PVC Pipe, motors, brackets, and screws.  For additional materials not within the Sea Perch kit, there is also a limited budget to be proposed (see Project Budget).

Pre-Existing Solutions

Most Sea Perch designs seem to have a similar design.

                     Figure 1: MIT's standard perch design

                       Figure 2: Sea Perch CTEA Teacher's workshop

Figure 1 is from MIT's instructions on a standard Sea Perch design.  The standard design consists of 3 motors and a PVC pipe framework.  The structure is made neutrality buoyant in order to allow it to move vertically in the water by using low density foam and additional weight to get the proper distribution.

Figure 2 is a Sea Perch from a CTEA Teachers Workshop. Note the reduced size and forward placement of the foam. The rear motors are positioned straight instead of at slight side angles, and the vertical motor is positioned in front of the center bar.

Design Goal
The group's Sea Perch design will be a modification on the "standard" Sea Perch design. However, the forward control motors will be moved forward to the centers of the left and right sides of the robot. These will be controlled by the switches on the face of the controller. The vertical motor will remain connected to the cross bar, and will be controlled by the two buttons on the top of the controller. Due to the possibility of an environment with moving water, the motors may be changed out for higher strength motors, and the power source may be increased.  This will help allow the submersible move against the current.

There is the possibility of adding a fourth motor. This will require modification of the controller. This motor will be one of two designs:

1. The fourth motor will be in the center of the robot facing the rear. When activated, the motor will give the robot a boost in thrust when moving forward. It will be controlled by one of the buttons on the top of the controller. The remaining button will have to be replaced by a switch to control the vertical motor.
2. The fourth motor will be in the center and facing to the side. It will allow the robot to move left and right without turning. In this case, both of the buttons will have to be replaced with switches.

The PVC pipe structure may also be altered in order to position the fourth motor in suitable position.

Project Deliverable


The deliverable that will be provided are a completed submersible that is able to move around in moving or static water.  There will also be a design plan and CAD drawing of the submersible.


Project Schedule

• Week 3 - Start developing a design for the submersible
• Week 4 - Will have a completed design for the submersible, and start obtaining any necessarily additional materials
• Week 5 - Start building the submersible, starting with the main body of it (to be made out of PVC pipe)
• Week 6 - Building of submersible, will try to have it completed this week
• Week 7 - Finish submersible if necessary, and test it in river conditions
• Week 8 - Make changes if necessary, Possibly a second test of the submersible
• Week 9 - Report and Presentation, tertiary test if deemed necessary

Project Budget


The cost of the project mostly are in the Sea Perch kit provided.  Some additional parts may be necessarily in order to complete it, but non of these parts should be more then a few dollars.  There may be a need to get a forth motor, which would cost about $20(probably less).  The overall budget for the project won't be significantly more.  A preliminary budget amount would be around $50, but there is a slight chance that this could be surpassed.  The materials in the Sea Perch kit will be enough for the majority of the design.