ROV Ranger Class Technical Report. High Technology High School Presents:

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1 ROV Ranger Class Technical Report High Technology High School Presents: GLADT-Good Luck and Duct Tape Teachers: Mr. Robert Dennis and Mr. Michael T. Roche Mentor: Mr. Bill Wetzel Andrew Shum Alex Jagendorf Bob Sherbert Chris Janover Dan Handlin Eric Ebinger Erin Fischell Franz Sauer Glen Stroz Jonathan Lui Team Members: Laura Nicholson Neil Supnekar Pat Hickey Peien Liu Robert Karol Steve Meisenhelter Tom Jackson Venky Srinivas William Steiniger High Technology High School Page 1

2 Table of Contents: Section: Name Page A Abstract of Project 2 B Photographs of Robot 3 C Budget and Expense Sheet 4 D Electrical Schematic and Explanation 5 E Design Rationale of Robot 7 F Description of Primary Challenge 8 G Explanation of Testing and Troubleshooting 9 H Lessons and Skills Acquired 10 I Future Improvements of Robot 11 J Job of ROV in Oil Industry 12 K Acknowledgements 12 Abstract: The robotics team of the High Technology High School concentrated time and effort upon the creation and completion of a robot that can meet the criteria outlined within the specifications for the Ranger Class of the ROV Competition. The Ranger Class division required that the robot be powered at a maximum of 13 volts and 25 amps, able to operate at a depth of 5 meters, and fit within an 80 centimeter by 60 centimeter by 60 centimeter area. In addition, the robot must be able to efficiently and effectively cap an oil well in the Gulf of Mexico, repair a damaged fiber optic cable connection to reestablish a communications link, and to install a new instrument module on the Hubble space telescope. In order to best concentrate and distribute effort amongst the various aspects of the robot, the team was split into distinct groups. There was a building and design crew that would cover the overall design and construction of the robot. Another group was the testing team that was responsible for the testing of components, such as the motors. In addition, the electrical team was responsible for the design of the electrical and control systems of the robot. Finally, a freshmen team was established to build their own prototype robot while gaining experience and knowledge from the more experienced members within the robotics team. High Technology High School Page 2

3 Photographs of Robot: The pictures of the current state of the robot are displayed in the area below. Based upon the inopportune placement of days off from school in relation to the documentation deadline, the robot was not completed. Though, the overall shape and basic features of the robot are visible in these pictures of the robot. These four pictures display the overall shape of the robot. The two pictures above this paragraph, and the picture below and to the right, display the shape of the robot and the location of the two motors that provide the main thrust for the robot. The picture below and to the left displays an upclose picture of one of the major motors. High Technology High School Page 3

4 Budget and Expense Sheet: For this robotics challenge, there was special attention paid towards the area of financing the endeavor as well as selecting the ideal materials while not exceeding the budget. The majority of the budget came in the form of a $3,500 donation from the company Class Link. This particular donation was crucial in allowing for the robotics club to complete the robot and compete in the competition. Furthermore, there was already numerous supplies leftover from previous robotics competitions, principally from FIRST, as well as materials that were graciously donated. Overall, the supplies required for this project only required a small percentage of our total available budget. Below, the items marked FIRST were the leftover materials from past competitions and the items marked DONATE were in fact donated. Item: Quantity: Category: Cost: Inflatable Pool 1 Testing $300 Victor 886 Speed Controllers 5 Electronics FIRST ($750 est.) Spike relays 1 Electronics FIRST ($35 est.) Power distribution block 1 Electronics FIRST ($50 est.) Breakers - Electronics FIRST ($100 est.) Waterproof crimp connectors - Electronics $20 Tether Cable 18.3 m Electronics Donated ($50 est.) Innovation FIRST 2004 controller 1 Electronics FIRST ($500 est.) and operator interface Analog Joystick 2 Electronics FIRST ($100) Attwood 500 Bilge Pump Motor 4 Propulsion With item below Attwood 750 Bilge Pump Motor 2 Propulsion $70 Rule 500 Bilge Pump 1 End Effector Donated ($20 est.) Propellers - Propulsion $30 Connectors - Propulsion FIRST ($25 est.) PVC Pipes - Propulsion FIRST ($20 est.) Metal Components - Propulsion FIRST ($75 est.) Beams and Connectors Frame $175 Camera 1 Frame On Loan from MAST ($500 est.) Total Cost from components:$595 Estimated Total Cost including donated and other free materials: $2,790 High Technology High School Page 4

5 Electrical Schematic: Since our team is composed of a group of students who formerly competed in the FIRST Robotics competition, we took advantage of the equipment provided to us through last year s FIRST competition because of our experience in the usage of such equipment. Coming from the power supply provided for us at the competition, we first have a 25A fuse assembly in series with all of our other electronics. The wires from the fuse and the ground go to a breaker block, which provides all of the devices we plug into it a common ground and their own independent 20A circuit breaker. In this manner we distribute power safely and by removing the breaker we can independently disable any subsystem of the robot. For regulating the speed of our six motors, we have five Victor (some the 883 and some the nearly identical 884 model) speed controllers. Each one of these five Victors is fed 12 volts via a separate breaker on the breaker block using 16 gauge wiring, as well as having a 16 gauge ground wire attached to it. These Victor speed controllers provide us with fully proportional power output from -12v to +12v, at up to 35A. We also have a feed off our breaker block for a Spike DC relay, which provides an output of either -12v, 0v, or +12v. The Spike relay, for additional safety, has a replaceable 20A fuse on its incoming connection. Another feed off our breaker block is designated to power the FIRST 2004 Robot Controller and Operator Interface. The Robot Controller provides us with the Pulse Width Modulation (henceforth PWM) outputs necessary to communicate with the Victor and Spike motor controllers. A three connector PWM cable runs from each motor controller to the Robot Controller. The FIRST Operator Interface provides us with inputs for analog, 25 pin connector joysticks. We are using two of these joysticks for the control of our robot- one to provide us with linear X and Y axis movement (forwards, backwards, left, and right) and a second to provide us with linear Z axis movement (up and down) and rotational XY plane movement (turn left and turn right). The trigger button on the first joystick is designated to open the claw, and when it is released the claw will close. The Operator Interface is linked to the Robot Controller via a standard RS232 cable, and is provided with power via that cable. The Operator Interface is, electronically, a dummy- it simply takes the inputs from the joysticks, turns them into a digital signal, and sends that to the Robot Controller. The Robot Controller has a microcontroller which runs code to process those inputs and output to its PWM ports accordingly. The Robot Controller is programmed, by team members, in the C programming language. The Robot Controller provides us with a lot of flexibility in control because we High Technology High School Page 5

6 can set minimum and maximum outputs to our motors in software rather than hardware. The final feed off our breaker block is to power our camera and monitor. We borrowed the underwater camera system from another school in our district, the Marine Academy of Science and Technology (MAST). The camera has a four connector tether cable which connects directly to the television- one contact to power of the camera, one contact to power the LEDs arranged around the lens, one contact for the video signal, and one contact for ground. Since we did not want to modify the camera in any way other than mounting it to our robot, we decided that we would have to power both the monitor and camera from our power supply which draw a total of 1.4A. Traveling to our robot is a 60 tether cable donated to us by Cortland Cable. The cable has 17 conductors of approximately 18 gauge, as well as several other coax and fiber lines which we did not utilize. Of the 17 power conductors available, we utilize only 14. Each motor receives its own independent pair of wires in the tether. For propulsion, we use 4 Attwood 500 bilge pump motors and 2 Attwood 750 bilge pump motors. We also used an unmodified Rule 500 bilge pump to hydraulically actuate our end effector. The High Technology High School Page 6

7 Design Rationale The design of the robot is the culmination of a process of critical thinking in regards to the specific areas that govern the performance of the robot. After this analysis of the specific areas, the compiled information in combination with the limitations in terms of funding, equipment, manpower, and time forged the final design. The base consideration for a design was its viability in a liquid immersed environment, especially in respect to their properties concerning water pressure. Also, the propulsion system was of key importance in terms of power necessary to move the robot freely through the water, but also in terms of maneuverability throughout the water for greater accuracy. Thirdly, there was a great deal of thought given to the camera that would be the only source of output from the robot and necessary to perform the competition tasks. Furthermore, the end effector was carefully selected in order to perform the wide range of tasks without fear of failure. For simplicities sake, the robot's structure would be composed of metal beams held together with connectors in order to form a rectangular prism. Furthermore the chosen materials are light weight yet extremely strong, as well as being common place. All such characteristics are crucial in a real-world environment where component failures need to be repaired quickly and waiting on specialized parts is unacceptable. The propulsion of the robot required considerable thought, given the necessity for the robot to be able to travel in almost any direction to ensure maneuverability. To complete this task, the robot has a total of six thrusters to ensure its maneuverability while underwater. There are four thrusters, which are placed at the four corners of the robot and face out diagonally in order to perform translation or rotation in the X or Y direction. The remaining two thrusters are of greater power and are placed in a vertical plane where they are strictly used for vertical motion in the water. The thrusters themselves were custom designed by the group in order to best accomplish the tasks needed to be performed. The thruster starts out with a bilge pump motor that is ideal for working underwater. The housing of the motor was unnecessary for our application and was removed. The impeller within the thruster was replaced with a propeller commonly found in model airplanes that would work perfect in this new setting. Finally, about a section of four inch PVC pipe was adapted to form a nozzle by which the force of each thruster can be concentrated. In essence, the nozzle was similar to the design of a Kort nozzle, but with obviously limited materials. Overall, this process allowed for the creation of a thruster able to perform underwater with a great deal of power. High Technology High School Page 7

8 The camera is of crucial importance towards the completion of the tasks since it provides the only means by which the operators of the robot can actually see the location of the robot in respect to the target. Thus, the camera is mounted on the front of the robot in order to have the best view of the path the robot is traveling in. Furthermore, the camera will be connected to an actuator that can change the camera angle as needed in order to get an advantage in certain situations. The end effector selected was a simple claw-like device that can be opened and closed with ease. The claw-like design was selected in order to keep things simplistic in order to avoid failure and ensure the device is easily operable. The end effector is placed on the front of the robot just below the camera. In this manner, the camera can be angled at the end effector and create increased accuracy during the missions. Description of Primary Challenge: Within this project, the primary challenge was in the ability to test the robot in a similar environment that the robot would function within for the actual competition. To accomplish such testing, it was required to have a large container of water that the robot could be placed within and conduct practice runs of the tasks as well as allowing the human controllers the chance to hone their skills. There were two distinct choices to solve this challenge, which were to either build a water containment unit or acquire a pool. Initially, it was thought possible to simply build a pool at High Technology High School to allow for easy access and low cost for testing the robot. The ideal dimensions of the tank would be four feet wide by eight feet long by four feet tall. Such dimensions, would allow for enough room to check the functionality of the robot and test the actual controls of the robot. Though, this proved inefficient in allowing the conducting of practice runs. Further, there was still the problem of constructing a mechanism that could place the robot within the water containment unit. The second concept that could solve the challenge was to simply purchase or find a pool that could be utilized for testing. Eventually, two pools were discovered that could allow for the testing of the robot. The first pool was one that could be purchased from K-Mart and set up at High Technology High School. The pool had a diameter of fifteen feet and was four feet deep. With such dimensions, the robot could be easily maneuvered in any given direction for testing of the controls and initial performance of the robot. The second pool that was located would be used in conjunction with the first. The second pool was an in ground pool at pool supplier which was perfect for testing the robot at the actual depths found within the competition. In this pool, practice High Technology High School Page 8

9 runs of the tasks could be conducted in order to make final adjustments in the performance of the robot. In addition to the situation regarding a testing environment, another challenge was a way of utilizing the testing environment in order to perform drag testing with the robot. Information regarding drag is crucial in order to better understand and calculate the motion of the robot as it moves through the underwater environment. In order to perform drag testing, a special apparatus was designed that could support the robot at a given depth in the water, yet allow for relatively free motion in a given direction parallel to the surface of the water. The apparatus consisted of two towers placed at either end of the pool. There two towers were connected at the top by two cables that spanned the diameter of the pool. Meanwhile, a frame was constructed that would have a piece of wood coming up at each corner with a notched wheel at the top in order to rest on the cable. The robot would be placed upon then frame and held at a specific depth in the water depending upon the distance between the four notched wheels and the frame. Finally, another cable would be attached to the frame and wired through a pulley at one of the towers and attached to a weight. In essence, the weight would be dropped and pull the robot through the water at a constant depth and the drag could be calculated. Explanation of Testing and Troubleshooting For this project, it is expected that problems will arise that require a general set of techniques in order for anyone within the team to overcome the obstacles. For this robotics team, the troubleshooting techniques can be divided into prevention of problems, which involves testing, and the actual process students go through when solving problems. The problems expected to occur in this project are expected to be in the electrical area in terms of controlling the robot and the propulsion of the robot. Any problem within those areas could result in failure within the actual competition. To eliminate such possibilities of failure, testing was employed to gain knowledge regarding the components most likely to go awry during the competition. The first conducted test involved determining the performance of each motor underwater given the limitations of the motor in terms of voltage and current. In order to perform this task, one of the motors was placed in a special miniature tank and water and attached to an apparatus that would measure the force produced by the motor. In addition, the voltage and the current supplied to the motor were carefully recorded. The data gathered from this experiment was utilized in order to determine the amount of force one motor could produce from specific current and voltage values, which is vital information. High Technology High School Page 9

10 Given the limitations of the power supply and motors, a combination can then be found to determine what settings are required for the motors to perform best. In addition, testing was conducted regarding the interface between the robot sending data via a camera and a human giving commands based upon such data. The setup of the experiment was one team member would take the role of the robot. The team member would hold a sample end effector and the camera. Another team member would stare only at the monitor for the camera and give verbal commands to the team member pretending to be the robot. In this manner, the process by which the robot will be controlled was better understood, and despite not actually testing with the robot, experience was gained in regards to the limitations and difficulties with the method of controlling the robot. In essence, this testing allowed for the team members to understand the importance of factors, such as depth perception, and could then learn to compensate accordingly. Besides preventative measure, the team utilized a basic set of troubleshooting techniques in order to solve a problem. Once a problem occurs, the particular team member begins by checking over the given components and determining if the setup is correct. For example, if a student is wiring a particular component that is not working properly, the student may check all wiring connections. The next step may be for the student to look over the components themselves to determine if there is an internal problem. For example, if a voltage meter is giving abnormal results, the student may find the voltage meter has an internal problem. If the team member can not solve the problem at this level, the member can seek out one or two other team members, possible those of greater experience with robots, to repeat the process of checking over the given components. Then, they can collectively assess the situation and brainstorm solutions. If at this level the problem can not be solved, the final step is to seek out the guidance of one of the teachers or the mentor in order to finally generate a solution to the problem. Description of Lessons Learned or Skills Gained The robotics competition is much more than working towards victory and success. Instead, there is also a learning aspect that must be acknowledged in order to appreciate the other benefits of this endeavor. With this competition, the main lesson learned resides within the importance of passing down knowledge and experience from the older team members to the younger team members. The skills acquired from this project primarily reside within learning the importance of time management and coordinating progress of the project from start to finish. High Technology High School Page 10

11 This robotics team consisted of two distinct groups of members, which were the older students that have been in the club before or have prior experience with robotics, and the younger students that wish to take part in the robotics club and help in the competitions. The older students were of the old robotics club at High Technology High School, which solely competed in the FIRST competition. The demanding nature of that particular competition led towards the creation of this majority of older students with great levels of experience in robotics. Meanwhile, the younger students entering the club this year were given the opportunity to create their own prototype for a robot that could be entered in the competition. The reasoning behind the decision was that the younger students could get basic experience and learn from trial and error the necessary knowledge for building a robot. Also, the older students could act as mentors in constructing their own robot. Thus, the importance of teaching the younger students the finer points of robotics and giving them the necessary experience was accomplished by mentoring and demonstrating concepts to those members without limiting the their ability to help construct a robot. The crucial skill gained from this competition was the importance of time management in meeting specific deadlines with allowance time for problems that may occur throughout the process. Within a project, some aspects may take much longer than expected and thus hurt the overall timing of the project. Though, it is necessary to have a plan in place that can account for the time given to such tasks, while allowing for overtime required. If tasks are taking too long and the deadline is fast approaching, an actual plan would have been beneficial in determining time and man power able to be allocated to a given task at a given time. Essentially, this competition taught each group member that a plan is necessary so that deadlines are not missed, work doesn t have to be rushed, and man power can be better distributed to more efficiently complete tasks. Future Improvements Within any project, there is always room for improvement in order to improve the performance, accuracy and efficiency of the robot. Though, sometimes time and deadlines do not allow for such changes to be utilized within the specified time period. Within this project, there are numerous improvements that could be made to the robot. For example, the number of motors could be reduced and stronger motors could be utilized. In this manner, the complexity of the electrical systems and calculating the physics of the motion of the robot could be simplified. In addition, the camera could be attached to more than one actuator to increase its range of motion and High Technology High School Page 11

12 therefore increase accuracy in the performance of the robot at locations the operators would otherwise be unable to visualize. Furthermore, the camera could be supplemented with sensors such as depth sensors that provide more feedback to the operators and thus make the tasks in the competition easier to perform. Finally, the overall size of the robot could be reduced by building a frame more suitable to the size of the mechanisms within the robot to decrease the weight of the robot, and consequently the amount of force from motors required to move the robot through the water. Job of ROV in Oil Industry As symbolized within the competition with the robot performing the oil well task, the ROV is of crucial importance within the oil industry. The ROV is utilized in areas within the ocean where it is unsafe or impossible for humans to travel. In particular, the ROV can be used for tasks from aiding in oil drilling, construction of pipelines, inspecting pipeline, and even repair work. The ROV can then perform such duties underwater and yet be controlled by workers at the surface. For the oil industry, the ROV can be used for what is deemed Special Intervention Systems. In that position, the ROV would be used for tooling. Another category includes the heavy work class of ROVs. The heavy work class includes the ROVs that are utilized for working at extreme depths of 3,000 to 10,000 feet for oilfield construction that no other machinery could perform. A third category is the intervention work class, which includes the smaller ROVs that are used for inspecting the various underwater pipelines and machinery as well as conducting repairs if necessary. Finally, the observation class is the ROVs that are responsible for inspecting underwater oil pipelines and machinery and send the visual data back to the workers controlling the ROV in a much more efficient and practical manner than sending a manned vehicle. Overall, the ROV is of crucial importance to the oil industry where there is a great depth of water. The particular oil well task in the competition is an example of one such job that an ROV could perform. Acknowledgements This project would not have been possible without the support of the teachers, Mr. Robert Dennis and Mr. Michael T. Roche, and also our mentor, Mr. Bill Wetzel. In addition, Class Link was crucial in donating the capital to finance this endeavor. Also, we thank the Marine Academy of Science and Technology for loaning the camera used in this competition. Furthermore, the supplies left over from previous FIRST Competitions were beneficial in the High Technology High School Page 12

13 creation of our robot. Finally, research and supplies were located through the following sources: Cortland Cable. Cortland Cable. < Kmart. Kmart < Markets Section. Perry Slingsby Systems. < ROV Committee of the Marine Technology Society. Remotely Operated Vehicle Committee of the Marine Technology Society. < ROV Competition. Marine Advances Technology Education Center. < The Art of Science and Control. IFI Robotics < Whitcomb, Louis L. Underwater Robotics: Out of the Research Laboratory and Into the Field. John Hopkins University. < For more information on this project, feel free to visit: High Technology High School Robotics Club. High Technology High School. < High Technology High School Page 13