Project Overview

Project Overview

Problem Overview:

The SeaPerch is an underwater remotely operated vehicle (ROV) constructed out from a kit supplied by the Navy. Originally, the SeaPerch kit was designed by Dr. Tom Consi at MIT as a tool to teach students the principals of marine engineering as well as basic applications of science. Today SeaPerchs are used for this purpose and implemented in competitions at High Schools and Universities across the nation. Currently, the SeaPerch is inefficient in both areas of its mechanical and physical design, due to its bulkiness and weak structure. The goal of this project is to redesign the propellers using a rapid prototyping machine. Additionally, the chassis will be redesigned to make the SeaPerch more hydrodynamic.

Design Constraints:

​            Without owning a sea perch kit it is very hard to understand the constraints that go along with this project. The group is restricted by what is included in the kit. It will be hard to produce a stronger motor than the one provided within our budget. Also, the amount of PVC pipe available for this project is limited. In addition, the sea perch must maintain a reasonable size to maintain its maximum speed. Available onsite is the rapid prototype machine, which will be used to design and produce new propellers. Restrictions found with is machine is in its capabilities. It can only produce small plastic propellers, not of a stronger material, which would have been more useful for this project. The environment available for the test of the SeaPerch is also of a concern. Although there is unlimited access to the river, it will be hard to test speed and maneuverability in the cloudy river that has currents pushing the sea perch. Ideally the original and final design will be testable in the Drexel swimming pool, however access to this resource has yet been confirmed. The last big constraint is the budget. The budget of this project ranges between $50-$100, there fore the amount and quality of material that is available is limited. Without the definite assurance of reimbursement from the university the budget must remain with in this range.

Pre-Existing Solutions:

            While researching the hydrodynamics of a SeaPerch, one may not find exactly what this group is looking for. In an effort to build an almost blimp like front, it seems like it hasn’t been done before. Instead there are numerous examples of barges. They feature a rectangle on the topside of the perch and then coming down to a triangle forming a floating prism. While this makes the perch very stable, it is not the blimp like shape that will break the water easily. It is hard to say without receiving the kit what modifications will exactly be made, but what the group wants to do seems to be the first of its kind. After receiving the kit and looking further into its design, the group will be able to determine the changes that need to be made in order to achieve an almost blimp like submersible. 

Design Goal:

​            The goal of this project is to redesign the sea perch to make it more hydrodynamic. Initial ideas are to make the frame much smaller and dramatically change the shape of the whole perch. The current design is very bulky and inefficient. It is intended that the new SeaPerch is not only more efficient, but more useful as well. If the group can make the SeaPerch’s more agile, then it will be of greater use and serve a wider application. Currently, the propeller design is not very accurate. Therefore, the plan for the propeller design is to change it’s the positioning, which will then allow the SeaPerch operator to input more accurate and precise commands into the device. Ultimately, the goal for the SeaPerch is to make a new design that can be taken by other people and used in more practical applications than it is currently being used for. 

​            The current design is not precise and has to be tethered to be controlled. If there is enough time in the course an attempt will be made to make the SeaPerch radio controlled. It has been decided that the perch radio controlled will make it more useful in practical applications in the real world. Compared to the way it is used now, which is only for school projects and educational purposes. It is important for this project, that the new SeaPerch is viable in real world practical applications.

Project Deliverables:

At the end of this project, a newly designed SeaPerch will be created and presented to the class. During the presentation, the team will demonstrate the modifications made to the structure of the chassis, as well as those made to the design and positioning of the propellers. These changes are expected to increase the SeaPerch’s maneuverability when submerged in water. During the presentation, a comparison of the original and new SeaPerch design. The new design will be expected to travel a set distance in a shorter amount of time. As stated previously, if the group has enough time, than this final design will be radio operated. If this design feature is possible than this too will be demonstrated. The overall final design of the SeaPerch will serve as the physical evidence of the plans set forth.

Project Schedule:

The schedule for this project begins in week three. The delayed start is due to the teams inability to accomplish much work without the assigned SeaPerch kit. Thus far, it has been decided on what the group wants to accomplish, how the tasks will be completed, and what team member will perform which job throughout the entire project and other minor details. By week four, the plan is to build the original design for the SeaPerch, and test it the Drexel pool to determine how much time it takes for the SeaPerch to move the length of the pool. 

Since the goal is to make the SeaPerch more hydrodynamic, by the end of this project the newly designed SeaPerch should be able to successfully move across the Drexel pool faster than the original design. In week five, the group plans to have the framework finished for the newly designed robot, shaped the way it was previously designed. Then week six will consist of adding propellers and other altercations necessary to make to complete the SeaPerch. The newly designed SeaPerch will be tested in week seven, on both its functionality and the duration that it takes to cross the pool. With this, the group can determine what changes need to be made to work or even more successful to be more hydrodynamic. Week eight and nine will be used for testing the changes made and finalizing the design of the SeaPerch. The SeaPerch will be timed to determine if the group in fact did make a more hydrodynamic SeaPerch that can move across the pool quickly. During this time the group also may chose to alter the propellers if it necessary to help the SeaPerch move at a better pace, and if time permits. This schedule will allow the group to keep on track throughout the project and have a completed, more hydrodynamic SeaPerch to show the class in week ten.

Projected Budget:

The group has yet to receive the SeaPerch kit and therefore is unable to come up with an accurate estimate of the types of materials that will be required for the design modifications. The following chart describes the types of materials that have been estimated based off of a rough idea of what may be required during the project.

Materials:

Item	Price Per Unit	Quanity	Total Cost	Installation
PVC	$2.61 per 1-1/4 in. x 2 ft.	Varies	10-20$	In the Chaissis of the SeaPerch
Wire	Varies	Varies	10-20$	Pricing for wire is dependent on type.
Oatey Rain-R-Shine 8 oz. PVC Cement	$6.43	1	$6.43