Remote Operated Underwater Vehicle Team

Transcription

1 Remote Operated Underwater Vehicle Team University of New Hampshire Submitted to: Frank Hludik Date Submitted: 10/20/ ROV Team: Joel DeMello Andy Morin Charles Bonnier Mirza Asceric Dan Kunyz Anthony Giuffrida Eric Heffron Mike Bentwood Bill Andreycak

2 2 Executive Summary [Contributor: Andrew Morin] The 2010 UNH ROV (Remote Operated underwater vehicle) team has the goal of designing, testing, and fabricating a working ROV in order to compete in the 2010 MATE ROV competition. This year s team consists of 8 senior level Mechanical Engineering students from the University of New Hampshire. An ROV is controlled using a tether which connects the robot to the user at the surface. ROVs have many practical uses including undersea exploration, investigation and repair of underwater facilities such as oil drills or pipes, as well as military uses such as mine de-activation. While the specifics for the competition will be announced in November, it can be assumed that the ROV will have to perform a number of basic tasks. To be able to accomplish these tasks the team will focus on three main elements: propulsion, buoyancy, and controls. From what is known about the competition, the ROV must be run off of a 12V battery limited to 40amps. Judging from past competitions, the ROV could need cameras and lights depending on the competition specifics. Initial steps in the design process include analysis of an ROV from a previous year in order to discover its strengths and weaknesses. Initial analysis of the previous ROV has shown some design flaws as well as some useful concepts. These include size of ROV, propellers and motors, wiring problems, as well as depth control. By analyzing the previous ROV, mistakes can be found early so that these issues can be resolved and the key design features can be incorporated into the new vehicle. In addition to this, components such as propulsion systems and frame designs can be tested at this time in order to determine the best possible design. The organization for the team was broken down into a four sub groups which were mainly based on the main elements of an ROV: propulsion, specialty, systems, and frame. Sub-group leaders were chosen and will be responsible for the budget and work of those pieces. They would then report to the group leader who checks progress on all parts in order to meet the project deadlines and budget constraints. This organization allows for everyone to work on each part while maintaining a single point of contact on the main portions of the design. In order to complete this project, the ROV team will need a work station suitable for a build, including locked storage for tools and parts. The team will need access to computers for analysis, a room for which meetings can be held, and the machine shop for fabrication. When the ROV is complete, the 8-foot deep wave tank will be used for testing. Fundraising for this year is going to be one of the greatest challenges for the team. To be able to compete at competition we will need to raise a total of $19, This money includes the estimated fabrication and travel costs for the eight students and two advisors. The funds to actually fabricate the ROV are a more attainable goal at roughly $3,000 which will allow us to create and present a working design of our thoughts.

3 3 Table of Contents Executive Summary... 2 Introduction... 4 Background... 5 Description of Approach... 6 Team Organization:... 6 Technical Challenges:... 7 Description/Justification for Required Facilities:... 9 Initial Timeline:... 9 Budget: Summary of Deliverables for the Project... 12

4 4 Introduction [Contributor: Joel DeMello] For the 2010 ROV project, the assembled team will be designing a remotely operated underwater vehicle (ROV). The design of the ROV will be heavily based on the previous one built by the 2009 team. Each year a competition is held by the Marine Advanced Technology Education Center (MATE) where competition guidelines are devised for ROV s to perform certain tasks under specific conditions. MATE has been the leader in developing industry driven skill and knowledge guidelines for many marine based occupations including: ship-board research technician, remotely-operated vehicle technician, hydrographic survey technician, oil spill response technician, and aquaculture technician. Any one or more of these actual occupations could be incorporated in the competition each year. In 2009 the competition was based on submarine search and rescue in which the UNH ROV team was able to compete. Improving on the designs of the 2009 team and meeting the engineering standards of competition is the main goal of the team. The components of the ROV can be subdivided into four main sections: frame, propulsion, controls, and specialty items. These focus items will make up the main components of the ROV. In industry, ROV s are designed and built for many different reasons and for many different tasks. There are more bulky and durable ROV s classified as Heavy work class typically less than 220 hp that are used for carrying and transporting heavy loads such as the Triton ROV which was built by Perry Slingsby systems for the development of offshore gas and oil industry telecommunications. These usually have a working depth up to 3500 meters. Others are small and more delicately built classified as General which means that they are typically less than 5 HP and typically the maximum working depth is less than 1,000 meters. They can also be equipped with intricate cameras and lighting for reconnaissance and maneuverability like the V8 Sii HD created by Ocean Modules which can obtain full 360⁰ range of motion in all three dimensions and is mounted with four high definition video channels along with a fiber optic umbilical cable ranging 2500 meters. All of these types of design considerations are needed to be incorporated in the design of our 2010 ROV because of the nature of the competition. Based on previous competitions, our ROV will need to be able to carry some sort of load by lifting and carrying an object efficiently through the water, as well as be equipped with cameras in order to give instant reconnaissance feedback, while being able to have skilled precision movement in the water. Overall the design of our product is expected to be a compact frame, fully programmed controls, with good visibility, while maintaining a neutrally buoyant state. This incorporates the successes of last year s designs as well as practices from industry. While the rules for the 2010 competition have yet to be posted by the MATE competition committee, these goals would fully satisfy the tasks of the 2009 competition and provide for a great set of guidelines for the upcoming competition.

5 5 Background [Contributor: Dan Kunyz] The motivation behind building a remotely operated underwater vehicle (ROV) is to compete in the annual competition organized by MATE. The exact constraints are currently unknown because the official rules have not been released. Last year was the first time the University of New Hampshire sent a team to the MATE competition. This presented the 2009 team with many challenges while designing their vehicle, and because most ROVs have similar elements, the 2010 team can learn from the previous model. There were a couple elements the 2009 team designed very well. The frame for the vehicle was strong, and finite element analysis showed it could stand up to an impact at ten times its maximum speed. The ballast system was very effective, and could be changed quickly. Bolts were placed on the vehicle, and washers could be added or removed from the bolts to control the overall buoyancy of the vehicle, along with the pitch. After consulting with the 2009 ROV team, several observations can be made. The overall size and weight of the vehicle were much greater than what was required to complete the desired tasks. This made maneuvering through the water more difficult, along with transportation of the vehicle from one site to another. The tether which connected the ROV to its control station was much longer than it needed to be and was also very heavy. The heavy tether held the vehicle back and prevented it from performing optimally. The propellers used to move the vehicle were trolling motors from a small boat, and were much larger than they needed to be. The propellers used for moving the vehicle up and down, and side to side had to be reshaped to fit on the vehicle. In the reshaping process the ends of the propellers were cut, greatly reducing the thrust they could create. One of the biggest problems with the 2009 design was that the vehicle was underpowered. The propellers weren't receiving enough amperage to operate effectively. Moreover, the power to the propellers was either on or off; there was no partial-speed option. Learning from past experience, the 2010 UNH ROV team will focus on building a smaller, more efficient vehicle which can move through the water with greater ease. To achieve this, different style propellers will be used, along with a frame that is about half the size of the previous model. A neutrally buoyant tether will be utilized to prevent it from negatively effecting the maneuvering of the vehicle. The new vehicle will also have much better control systems. It is intended for this year s ROV to be fully programmed whereas last year was all hard wiring. This method will take more work, but will be a much more effective and reliable way to operate the vehicle.

6 6 Description of Approach Team Organization: [Contributor: Eric Heffron] Team Lead: support all areas of the project where necessary facilitate road map, release schedules, and requirements track progress ensure that project stays on track and participants have clear objectives ECE Lead: support all areas concerning electric motors and control systems offer support and advice to Peripherals when needed ensure the safe operation of tether and onboard electrical devices Sub-Group Lead: support the areas of the project they re supervising report to the team lead on project progress Team Member: Work with all groups to accomplish the desired goals Be an active member in design and analysis

7 7 The organization for the ROV team is structured so that every member can work on all components of the project. The organization of each component is controlled by the sub-group leaders. The sub-group leaders control assemblies, budgets and schedule for the individual technical areas. The sub-groups are split up into the most important components of the vehicle, but despite this each group has to work with the others. This means that all information is then sent up to the team leader who makes sure that the assemblies are on time. The team leader makes sure that all the sub-groups are talking about the next step so that no one is held up by another group. The team leader controls the budget for the total project as well as assigning extraneous tasks like fund raising to all members of the team. Technical Challenges: [Contributors: Charles Bonnier & Bill Andreycak] There are various challenges inherited with designing an underwater vessel; such technical challenges include buoyancy, pilot controls & vision, propulsion, frame, and tether components. The team must fabricate or buy the components for the ROV, while staying within our budget and time constraints. Buoyancy A vehicle on the ground only translates in two dimensions. However, an ROV must also be able to travel up and down the third dimension. Therefore, we must determine a balanced buoyancy of the ROV. A negatively buoyant craft would sink, whereas a positively buoyant craft would float in the case the tether was detached. The team must determine how much water the ROV displaces while it is underwater to find a close estimate for its buoyancy. In addition, an adjustable weight system is to be implemented for fine-tuning. In addition, the tether will need to be neutrally buoyant so it does not have an effect on the craft s maneuverability. Propulsion Another challenge is deciding which kind of propulsion system to integrate into our design. Many possibilities exist for the propulsion of the ROV, categorized into two basic groups; propeller, and water jet. The majority of the research of this project is focused on the propeller category due to the low costs and many benefits. Waterproof, submersible bilge pumps are one route being explored, along with the idea of waterproofing a brushless DC motor. It is important to keep in mind the limited power being supplied to the ROV, along with the low speed, but high precision movement requirements. Testing will be completed to determine if a high-speed/low-torque or low-speed/high-torque motor and propeller combination best suits the design. There is a difference between translating and flying through the water. Depending on how we decide to move through the water, the positioning of these propulsors becomes important. Last year s

8 8 model used two trolling motors on the outer edges of the rear, a vertical thruster, and a horizontal thruster. Some simple vector addition of thrust on varying design ideas can be used to find an optimal arrangement. Controls Along with the propulsion, a controls system must be designed for the pilot to control the thrusters. The controls system must be analyzed heavily before an actual attempt to build it. Currently, the use of a microcontroller is being researched for its feasibility. This would allow the operators a very high level of precision when controlling the speed and movement of the ROV. The team must account for the response times of the motors and the vehicle s drift in the water must be so that the ROV is predictable and easily maneuverable underwater. The possibility of the motors being able to spin both forwards and in reverse is being considered. MATLAB and LabView will most likely be used for these analyses. Many options exist for the actual user interface for controlling the ROV, including hobby joystick sets and USB game controllers. Frame The frame of the ROV will need to be designed around the other components. Different materials and frame solutions will undergo finite element analyses for strength and rigidity under all possible loadings. Stress analysis will be done on different materials as well, such as aluminum or PVC piping. Accessories Lastly, cameras and possibly lights will need to be implemented into the design, since the pilot cannot directly watch the ROV in competition. Last year, the starboard (right) side of the ROV got hung up on an underwater structure, but could not see because they only had a camera on port. The placement of these cameras will be key for the pilot s vision, because the teammates guiding the tether cannot communicate with the pilot either. However, these items will be the last to be installed on the ROV, because they can be run on their own personal power supplies, separate from power supplied from the surface. Currently, USB-interfaced personal web cameras, and underwater Fishing-Cams are being investigated. The lighting issue can be addressed in many ways, including small battery powered waterproof LED flashlights.

9 9 Description/Justification for Required Facilities: [Contributor: Charles Bonnier] To be able to effectively complete the challenges ahead, the ROV team will require space for planning, storage, fabrication, and testing. The planning space required includes large tables for group meetings as well as a white board for notation of ideas. This initial space will be used for the planning stage. The fabrication stage will require the use of the machine shop as well as locked storage space in order to store components and tools necessary for the project. The testing stage of the project will require the use of the eight foot dive pool in the Chase building. There we can test the 2009 ROV to see design flaws as well as test the 2010 ROV and new propulsion system. These different spaces are required at different times during the production process but access to all spaces is necessary for the successful completion of the project. Initial Timeline: [Contributor: Eric Heffron] The initial timeline of the project is separated into six sections. The first section is the initial presentation and information about the project. This includes the first deliverable for the ME755 course as well as a generic letter to possible sponsors. This information is then used to increase the initial budget in order to provide purchasing power for later in the fabrication and test process. The second section is using our gathered information to analyze and restart the old ROV. The old ROV is used as a stepping stone in order to see where our project can improve. The third section is selecting a type of propulsion and going through the design matrix. Once a type and style is selected then it needs to be purchased and pool tested. If what was selected holds up to the testing then the frame can start being designed around these components. The rules come out around November 15 th which means that the rest of the components cannot be selected until then. Around this time the initial design can be created with the cad software and analysis can be done to set up other components like buoyancy. If this initial design fits with the goals of the project then fabrication can begin on a test ROV. This test ROV will be a shell with a tether than incorporated everything needed for the final design. If the initial design survives the pool testing then any changes or modifications can be made for calling it the finalized design. At this point the finalized report and other deliverables needed can be focused on.

10 10 Final Design SeaCat 2.0 Schedule Tank Testing Initial Design Buy/Test/Select Propulsion Completed Remaining 09 ROV Operational Deliverable 1 5/17/2009 7/6/2009 8/25/ /14/ /3/2009 1/22/2010 3/13/2010 Budget: [Contributor: Eric Heffron] The total projected cost of the ROV project this year is $19, which as shown on the next page is broken up into fabrication costs and travel expenses. The breakdown on those totals is $2, for the fabrication of the ROV including all electronics and presentation costs. The travel costs have been broken down into flights, housing, and food. These costs total $16, which is almost five times the cost of the actual ROV. To be able to raise this money we will be targeting those groups that use ROVs in their work. The oil companies as well as ship builders are the primary contacts as they define most of the requirements when it comes to the design of an ROV. The budget it going to be a tough sell with how low the economy is but we believe that it will be possible to meet our mission objectives to produce a working ROV.

11 11 Description: Projected travel Budget: Flight* $10, Room/Board** $5, Food*** $ Shipping $1, Total Travel Cost: $16, *Travel Expenses Estimated using a multiplier of 10 **Guidelines say MATE will be providing room and board ***Food Costs Based on $15 per meal per person Description: Projected Project Budget: 1 Material Costs $ Aluminum Pipe $ PVC $ Hardware(nuts/bolts) $50.00 Injection Foam $ glue/paint $50.00 Machine Pieces $ Ballast System $ Propulsion $1, Electronics $ Control $ Wiring(cat5/10gauge) $ Joy Stick $ Teather $ Foam Sheathing $ Hardware $ Connectors $ Presentation $ Copying $ Poster $50.00 Shirts $ Total Build Cost: $2, Projected '09-'10 Expenses $19,190.00

12 12 Summary of Deliverables for the Project [Contributor: Mike Bentwood] Utilizing the engineering knowledge provided by the University of New Hampshire, the UNH ROV team will design, construct, and test an aquatic robot to explore the ocean floor. The challenges that we may face as we move into this year s competition are varying in nature. The project goals are to design, construct, and test an ROV. The team will use fluid dynamics, electronics, and mechanics to remotely control the vehicle with precision and accuracy. The ROV must maintain balance, travel multi directionally, view the ocean floor using multiple cameras, as well as be able to take data readings such as temperature and floor samples. Each member of the team is assigned to a certain design aspect of the project. As each team member designs and redesigns their part of the ROV, the different areas will be brought together to construct the final aquatic vehicle. Fluid dynamics will be studied in the design of proper propellers and movement through the water. Electrical engineering will be required to remotely control the robot. The different motors, accessories, and structure will utilize the study of Mechanics. The electrical engineering aspects of the project will involve successfully being able to control the different motors and mechanical devices from the surface. The most important part of this will be doing so while keeping all accessories waterproof. Electrical boards and circuits on the water craft and in the control box will have to be designed to be able to run on a 12v car battery. They will need to be engineered to run for enough time to complete the task and not kill the battery. The overall mechanical design of the vehicle will require the team to make sure the ROV balances within the water and doesn t flip over. The aquatic pressures and forces acting against the vehicle will be taken into account. Examining these forces will ensure that structural aspects don t snap or bend under the water. The different accessories of the ROV, such as a mechanical arm, floor sample device, lights, thermometer, infrared camera, and visual cameras will be designed to be waterproof. The mechanical arm will be designed to extend and retrieve small objects such as rocks or plants. The thermometer will extend in order to take readings of thermal vents while keeping the ROV at a safe distance. The visual and infrared cameras will need to be housed in waterproof cases that will not overheat the devices. One of the accessories to be designed will be a device to take a floor sample in order to study the environment that the ROV is operating in.