Department of Mechanical Engineering Technology

International RoboBoat Competition Autonomous Surface Vehicle

Student Participants

David Cappiello Ernie Camposeco Tyler Holbrook Munirr Sesay Stephen Strube Robert Williamson Conner Brockett

[email protected] Course Instructor Dr. Moustafa R. Moustafa Faculty Project Advisor Dr. Cheng Y. Lin

Date Submitted 04/23/2015 Department of Mechanical Engineering Technology

2 Department of Mechanical Engineering Technology

TABLE OF CONTENTS

Letter of Transmittal…………………………………………………………………………….1 Abstract………………………………………………………………………………………….3 Equipment List…………………………………………………………………………………..4 Introduction……………………………………………………………………………………5-11 Discussion……………………………………………………………………………………12-15 Conclusion……………………………………………………………………………………...16 Appendix 1 & 2………………………………………………………………………………...17 Appendix 3……………………………………………………………………………………..18 Appendix 4 & 5………………………………………………………………………………19-20 Appendix 6...…………………………………………………………………………………21-22 Appendix 7…………………………………………………………………………………...23-25 Appendix 8…………………………………………………………………………………...26-34 Appendix 9…………………………………………………………………………………...35-39 Appendix 10………………………………………………………………………………….39-48

ABSTRACT

Over the last several years the department of Mechanical Engineering Technology (MET), from Old Dominion University (ODU), has taken part in the yearly RoboBoat Competition that is hosted by the Association for Unmanned Vehicle Systems International Foundation (AUVSI). During the competition teams of various students are required to navigate autonomous surface vehicles (ASV’s) through an obstacle course. The ASV of their own design must perform several mission tasks including aquatic navigation, obstacle avoidance, autonomous docking, acoustic beacon positioning and an interoperability challenge. The skills developed, in aggregation with completing the competition, help engineering students not only achieve a realistic mission, within a maritime environment, but also serve to shape team building expertise needed for future endeavors. This report represents a comprehensive discussion of the design and analysis, associated calculations, manufacturing of parts, and procedure used to complete the construction of the ASV, in compliance with competition standards, as well as a financial examination and any pre-competition testing information that was performed by ODUs MET senior design team. The next competition is scheduled to take place July 7th-12th, 2015 and, foregoing any unforeseen circumstances, the ASV will be competition ready.

DISCUSSION: At the beginning of the spring semester 2015 our group inherited the ASV (Autonomous Surface Vehicle) from another senior group headed by Dr. Lin. The team got together to discuss the avenue in which we should ensue in order to tackle all the work required, for the upcoming semester, to get the ASV ready for competition. During the meeting we decided that the best route to take would be a split group approach, the same as the previous semester’s team did. The team was divided up into two separate groups, one group would be conducting testing and troubleshooting on Tuesday morning, from 10:00am till 1:00pm, consisting of Stephen Strube, Ernie Camposeco and Robert Williamson. The second group would be Friday morning during the same time slot and that group would consist of Conner Brockett, Munirr Sesay and Tyler Holbrook. Since we had seven group members total it was decided that the team leader, who is David Cappiello, would attend both meetings throughout the week. This was a general guideline and represented the two main meetings, one of which was mandatory each week, but by no means represents the full extent in which the work on the project was conducted. Many times throughout the semester several members, from both groups, attended multiple meetings outside of designated meeting times, to troubleshoot and fix any problems that were encountered during pool trials of the boat. The very first official meeting that we had as a team was hosted in Kaufman hall, in the automation and controls lab, all team members, save one, as well as Dr. Lin attended. During the meeting Dr. Lin informed us that pool trials must commence immediately and that we needed to decide, as a team, on when and how this would be conducted, he also informed us that the Coordinator of Aquatics, had agreed to allow us use of two of the lanes at the pool, located inside the student recreation center (SRC), outside of swim team practice. Once the general discussion, the assessment of what we had inherited, from the previous team, and what Dr. Lin’s expectations were for this semester’s team was concluded Dr. Lin jumped straight into showing us the ASV in which he gave us a breakdown on the boats components and electrical wiring. While showing us the boat he informed us that the first run of the program always yielded bad results and that the collection of data could not commence until the second run of the program. Then Dr. Lin began brief tutorial on the program LabView. LabView is the ASV’s work horse program that carries out all the commands for the boats execution, from straight line, and square to angle testing. From the very beginning there were problems, and an apparent foreshadowing of the difficulties we would encounter, as a team, when one of our group members was not present as well as the complications getting the boat to work properly. During the first couple of attempts to dry run the program, in the lab, there appeared to be no signal getting through from either the PLC to the ESC or the ESC to the thrusters. At first we were slightly intimidated, we had no idea where to even start but Dr. Lin showed us a general walkthrough on how to trouble shoot the system and components. We began the initial troubleshooting by ensuring proper voltage from the batteries to the thrusters and PLC, once we ruled out that the batteries were charged and they were putting out the proper and required voltage we moved on (Appendix 9, Figure 12). The next phase of troubleshooting began with ensuring all the connections were properly together, we unplugged everything from the batteries all the way to the thrusters, kill switch and PLC, we then plugged everything back in, ensuring that all components were attached properly and that all couples, between them, had solid connections (Appendix 9, Figure 15). All this was done to ensure that there was not an unwanted ground anywhere and that the signal, from one component to another, was not being dropped in between. After everything was plugged back in it appeared that the program was still not working properly, and by this point we were unsure of exactly what to do next so we decided to just try and run the program once again. The last attempt at running the

5 Department of Mechanical Engineering Technology program, and checking for proper thruster operation, worked. The team as well as Dr. Lin had not entirely understood why it worked this time, but it appeared as though the ASV and software had fixed itself. We went ahead and concluded the meeting, at this point, and decided that we would aim to have the boat in the water next time we gathered. Unfortunately the next meeting, which was held on Tuesday, February 3rd, 2015, did not go quite as planned. We began the day by loading the ASV into the back of the truck and driving over to the SRC. Once at the pool, before unloading the boat from the back of the truck, we ran into a complication. In what can only be described as spontaneous combustion, Stephen smelled the burning of plastic and when Ernie looked down he confirmed that a cloud of white smoke was emanating from the boat. We observed that the smoke was coming from the interior of the ASV and Stephen immediately recognized which wire was burning and without thinking stuck his hand in and disconnected the usb printer cord which connects the PLC circuit control box to the laptop used to send it commands. The wire was smoldering at the end that was connected to the PLC. Due to being unaware of why the connection had melted we took the ASV back to the lab with Dr. Lin where we began diagnostics and after an initial talk, discussing safety and proper protocol for dangerous situations, we began to try and figure out what caused the burning of the wire. Upon inspecting only the plastic had burned and the components seemed fine. We used a multimeter to determine that there was indeed no power going to the controller, therefore, no reason for the wire to burn like that. Ultimately the cause of this mishap was never fully understood and we began the process of fixing the mistake by reconnect a new cable from the PLC to the computer, to no avail. We were still unable to get the thrusters working properly even though there was a voltage coming from the PLC when we tested it. We concluded the group here and left the remainder of the troubleshooting to the Friday group. The Friday group started there troubleshooting by ensuring that all the wires were properly connected and that there was adequate voltage coming from the batteries, through the PLC to the ESC and ultimately the thrusters (Appendix 9, Figure 13-14). Once power was verified to both ESC and thrusters, the system was energized, to verify a tone from the thruster, and proper operation of the equipment. The Friday group, on top of troubleshooting the boat, also came up with the proposed team name of “LINSANITY”, a tribute to the project advisor, and discussed the registration fee and developing the website for the team. We ran into another problem the following Tuesday with the signal to the ESC from the PLC and also to the thrusters. We determined that the whole boat should just be rewired to ensure that there was no short in any of the wires that were previously installed, and to ensure that the connections were making proper contact with one another (Appendix 9, Figure 10-12). After rewiring the boat we finally had a good response from the left thruster and ultimately determined that the problem was with the connection from the ESC to the thruster, the connection is very sensitive and must be securely fastened together for proper operation (Appendix 9, Figure 16-17). In order to ensure this doesn’t occur ever again we stripped all the wires and crimped them into male and female tabs, this was done for both thrusters and after rewiring the whole boat and ensuring proper operation, of both thrusters and their associated ESCs, we added Velcro to the bottom of both batteries and the bottom of the boat. We also added a metal support bracket around both batteries. We began building the battery mounts which Robert Williamson brought with him as well as two ¼ threaded rods, four ¼ wing nuts, a small pipe bender, an electric drill and drill bits. We measured the batteries, made four 90 degree bends (2 in each threaded rod) that would wrap around the batteries, fit the batteries with the battery bracket in the boat, marked the drill holes in the side of the boat and proceeded to drill the four holes. The batteries then could be placed within the “U” shape bracket and be tightened up against the boat walls with the wing nuts on the outside of the boat. This was

6 Department of Mechanical Engineering Technology all done to add further rigidness to prevent disconnect and sliding during transport (Appendix 9, Figure 21). The first day that we were able to get the boat in the water and make some real progress came on Friday March 6th 2015. The reason for such a late start was, on top of the time wasted on rewiring and troubleshooting, inclement weather during the month of fall left very few days in which anything could get done. The school was closed and this left us scurrying to catch up once March rolled around. On the day we made it to the pool, the group arrived at Dr. Lin’s office to get instructions for the day, which were to do straight line testing in the pool. The testing, overall, went very well, we started with a three foot test and worked up in increments of two feet. Throughout the testing the boat remained straight and the reverse thrust was able to overcome the inertia of the boat and stop within a very small margin of the desired distance, while still remaining straight. Initial 90 degree turns were also performed and accurate except a few times when swimmers running laps in nearby lanes would interfere with the boat slightly. Also we did an initial “square run” to see where we were at in that department. The reverse thrust at this value proved too high and so we increased it to a 10’ by 10’ square. There was room for improvement but for an initial run we were happy. Unfortunately the good fortune was short lived, once we reached the ten foot mark the boat began drifting to the right and it appeared that the left thruster was overpowering the right one. We tried to adjust the value for the thruster but, at this point, were not very versed in the subprograms or the values in which needed to be changed. Ultimately it was decided to take the boat back to the lab and consult Dr. Lin on the proper manipulation of the program so that we could avoid this situation in the future. The next group meeting began with Dr. Lin informing us that he needed the group to perform angle testing with the boat. We decided that the best way to approach this was to mount the laser on the boat and use the arctan equation. To find out the angle the boat traveled we would have to use the horizontal distance traveled by the laser divided by the distance the boat is away from the wall, this value, in inches, would be plugged into arctan(value) to give us the angle value. The problem we ultimately ran into with this method was that the laser, which had to be mounted where the thrusters were in order to get an accurate reading at the center of rotation, was blocked by the laptop. We solved this problem by just mounting the laser facing the backwards, instead of forward, and still using the same method to obtain a value for the actual angle traveled versus the angle that was typed into the program. Once we were able to gain data, using this equation coupled with the “L-exact” and “R-exact” programs, we concluded that the actual angle traveled was very close to the angle desired and that adjustment was unnecessary at this point. We concluded the meeting at this point and were very satisfied with the amount of work we accomplished and hoped that from here out that testing would be much smoother than it had previously been. After this round of initial tests were complete we attempt to run the next round of forward run tests and get them exact. The problem encountered was that the left backward thrust would shut off slightly earlier that the right which would lead to the boat turning slightly to its right after the program was finished running. The boat lost the right thruster at around 10.6 volts indicating a battery problem unbeknownst to us at the time. This continued to haunt us as the next time we ran the boat again we got an initial low battery reading of 11.7 volts for thruster and 10 volts for the PLC. Not surprisingly this led to inconsistent angle testing values as well as limited time in the pool due to the batteries dying down. Up until this point we simply thought Dr. Lin might not be charging the batteries. After speaking with Dr. Lin he assured us the batteries were being charged every time. At this point we began to get a little frustrated with the data we kept getting as Friday group was doing and getting something different as well as Tuesday group getting and doing something different. This was

7 Department of Mechanical Engineering Technology especially confirmed by Ernie because, at this point, he had begun to come every single meeting to ensure some continuity in both groups and could attest the same things were being done with both groups. The adjustments readings and results were different each time, especially when it came to angle testing, and the frustration came to a culmination, when the neutral values were tweaked by accident. Research was begun to asses why every run was giving us inconsistent readings and this led us to contacting our predecessors. David was able to obtain a chart from the previous group indicating that below 11.9 volts the battery suffered significant power loss and below that value all the data would be skewed inconsistent and inaccurate thus, we had our answer. This led us to believe our batteries had become faulty and Stephen Strube purchased another similar set of 12 V batteries. It was from the charger included in that purchase that Dr. Lin figured out the charger he had been using to charge the batteries was the cause of our extremely low power level in our batteries. The following week we continued with the straight line testing, to obtain the delinquent values from the previous week. Dr. Lin had also added a second forward function, which was a forward movement, a stop and then another forward movement, and asked us to record the backward thrust values that would stop the boat both distances at the exact input value. We encountered a problem with this program where the left backward thruster would shut off earlier than the right one, which was causing the boat to turn slightly in between forward movements. This prevented us from being able to get an accurate straight line test due to the angle the boat would move. We tried to adjust the thrusters to go straight however, the boat power voltage dropped below 10.6 volts causing the right thruster to not respond to the input. At this point we ended the day and researched ways to make the batteries last longer. We decided that the only way to increase battery life was to either upgrade the batteries to deep cycle or to buy replacement batteries that we could change out when the voltage, for the ones we were using, dropped below a specific value. Once we obtained replacement batteries we again conducted angle testing to ensure that the previous values were accurate. We started by doing a 45 degree angle testing, both left and right, and based on the values obtained, concluded that the there was a large discrepancy in all the values we had obtained. All of the other angles showed similar signs of being over their intended values, with 5-10 degrees and 80-90 degree being off by about 6-8 degrees degrees and steadily increasing until the 45 degree mark, which was off by 15 degrees. We suspect that battery power being below minimum requirements had something to do with the values obtained before being so close and therefore had to re test all the angles from the previous tests. We also, at this point, found the paper from the last team (fall 2014) that indicated when the battery voltage dropped below 11.9 volts that inaccuracies in the tests began to surface and that in order to get accurate readings we must stay above this value. The laptop battery died after 1.5 hours of testing at the pool so we were unable to conduct any other testing after this happened. Although the battery died before we could obtain any more values, we were still able to get a lot of work done on the angles and when we consulted Dr. Lin, on the laptop battery problem, he suggested running a power adapter from the 12 volt battery to the laptop. We took this recommendation under consideration but ultimately decided against this because of the risk at letting the voltage drop below the minimum. Now that the group is back on track and we have replacement batteries, which are properly charged, we had to perform the straight line testing again, in order to obtain accurate results for that test. We began with 3 feed and performed that test as well as 5, 10, 15, and 20 feet tests. We also, if time permitted, would try and perform intermediary values for those tests. With the new batteries the back thrust had to be adjusted drastically, with the 3 foot test the initial value was 3.2 for the reverse thrust, which caused substantial overshoot therefore we adjusted the value to 2.0, which stopped the boat at

8 Department of Mechanical Engineering Technology almost 3 feet exactly. As we proceeded up through the tests the value for back thrust had to be continuously adjusted in order to compensate for the increased inertia caused by the forward thrusters. The values became so out-of-sync that we decided that instead of changing the reverse thruster value that we should instead change the forward thruster value. This was concluded, in part, because in the 10 foot forward run, even with a high back thrust value, the boat still stopped just over 13 feet, which is a 30% overshoot and as such was far too big to be considered satisfactory. On top of the overshoot, the left thruster also appeared to be starting a fraction of a second sooner than the right thruster, which was causing the boat to end up far right of its target destination. To compensate for this we tried to adjust the time delay in the left thruster versus the right thruster, we were unable to correct the problem so ultimately we ended up return the value to their original number and at this point ran out of time at the pool. As such, we concluded the group and decided it would be best to consult Dr. Lin on the problem at hand before anymore pool trials be conducted. It was at this time that we had an intermittent group meeting to discuss the course of action that we would have to take in order to have the ASV competition ready by the deadline. During this intermittent meeting we attached the equilibrium weights on the boat with Velcro, in a position that would keep the boat level in forward and sideways measurements, we also attached the tool box to the boat using Velcro and secured the weights to the front of the ASV using Velcro as well (Appendix 9, Figure 18-19). We were unable to perform any pool tests today because the pool was off limits, but are still scheduled to meet Friday April 10th, 2015, to resume testing as scheduled. Once we arrived at the pool during the next scheduled meeting, we were met with an immediate problem that required troubleshooting. When we tried to perform the initial dry run, before putting the boat in the water, the right thruster was not working at all. We attempted multiple different programs but the thruster was still unresponsive so we decided to take the boat back to the lab, where we met Dr. Lin, to conduct troubleshooting so that we could attempt to fix the problem. We verified voltage to the ESC, verified control signal lights changed while running the program, and ultimately swapped control signals for the #1 and #2 ESC to the thrusters to see if it was the ESC output signal, which it appeared to be. However upon further investigation, and much trial and error, we concluded that the actual source of the malfunction, as well as the power issues in the thrusters, was attributed to bad connections leaving the PLC to the ESC. We unplugged all the wires into the ESC, soldered the two red wires and then reconnected all of the wires back into the PLC (Appendix 9, Figure 20). After we soldered the red wires and reconnected the others we performed a dry run to test the new connections, which went very well. It is critical that we do not let another issue like this set us back as far as this one did, we ended up losing three pool testing days because of faulty wiring from the PLC. In order to achieve this we secured the PLC, to ensure that it would not slide around during transportation, to the bottom plate of the ASV. This was done using a wooden ½” by 1” plank of wood that we cut into three sections, two for the sides and one for the back, as well as adding two metal quick connects to the front to allow for quick release of the PLC when needed (Appendix 9, Figure 25). We also secured a thin foam mat in the area, the PLC will rest, to absorb any vertical shock that the PLC might encounter (Appendix 9, Figure 24). In addition to securing the PLC and any subsequent work that was performed on it, we also mounted the camera to the back cross member of the ASV (Appendix 9, Figure 22). The camera mount was provided by Robert Williamson who built it at work using a die set to thread a steel rod for the camera to screw into while also having a backing wingnut to stop the camera from spinning at the desired location. He welded the steel rod to a base plate and drilled two countersunk screw holes. He then made a joining base plate that is made to pinch a rear boat beak with the top mounting plate and the joining plate which ultimately mounted through the back metal cross member (Appendix 9, Figure 23).

The last day of testing before the report was written was very unproductive. The problems, which was inactivity from the left thruster, started when the dry run was conducted. We checked the batteries and all the connections to subsequent components to ensure voltage through the system and finally found the problem, which was a connection problem. The PLC connectors were reversed and needed to be plugged into the proper ESC connections, the proper setup is the 1 PLC to 1 ESC-in and 0 PLC to 2 ESC-in. This solved the problem and the group was able to conclude the straight line testing and get the required data for that test. On top of that they also conducted the square turn program and concluded that each turn went over the desired 90 degree turn and concluded that the square turn is not calibrated to the new values and further testing would have to be conducted to calibrate the angles properly.

CONCLUSION The biggest issues faced during this project was the learning curve associated with knowing, the software, and the troubleshooting of various roadblocks encountered as well as the plethora of problems and setbacks that were encountered this semester. We feel as if there should be a better way to approach this project for future teams. First of all we believe that many of the problems that we ran into were inherited. A great deal of the work what we did this semester was fixing mistakes made by the previous group. For starters wires were mislabeled or unlabeled, there was zero color coding of wires, extensions were added to wires that were a different color making it easy to mix positive and negative, there were plugs that have nothing going to them, and the wires were jumbled and laying everywhere, which made it near impossible to differentiate power in and power out. With that being said the fixes we made to the ASV, from the very start, including: Rewiring the entire ASV, purchasing replacement batteries, replacing all of the connections between components, purchasing a proper camera, and soldering loose wires that were twisted around one another. Other than the inherent problems with the design and fabrication of the boat, there was a serious lack of communication between the two groups our team split up into. One of the main reasons for the lack of communication was the absence of leadership on the Team Leaders part. He was supposed to attend both group meetings each week to maintain the flow of the project throughout the semester. Unfortunately that did not happen and we ended up working as two separate groups on the same project, playing tug-of-war with one another trying to decide the best direction in which to proceed. One suggestion that we would have is ensure that the person taking on the role of team leader has the time and dedication, which is required, to ensure that the discussed plan of action is maintained. Otherwise subsequent groups will end up, as we did, chasing their tails round in circles to no avail. We also propose having the team that decides to take on the responsibility, of a school sponsored project, submit their proposal earlier than their peers and to have them meet with the original group before the end of their introductory semester to ensure a smooth transition between teams. Also previous knowledge of the PLC controller and how it connects into the fuse box through the circuit breaker and back out to the thrusters, as well as the operation switches and kill-switch components and functions would be extremely beneficial to our successors in this project. Other than the inherited problems and the ones we created for ourselves the Team overall did a decent job of accomplishing most of what was required, by Dr. Lin, in preparation for competition. We were able to get readings for the straight line test, a left turn test, a double forward test and the square test.

This was all achieved even though we ran into a great deal of problems and setbacks, the least of which was having multiple weeks in February that we were unable to achieve anything due to inclement weather and the university shutting down. There are still a few tests that need to be conducted to include a vision test of the camera and right side angle testing. Overall, it has been a pleasure working, in conjunction with Dr. Lin, on this university funded project and we believe that the ASV can still be ready for competition in July, barring any more unforeseen setbacks. In order for this to occur however, it will take a great deal of dedication by the subsequent team and a strong leader to overcome the time that we lost dealing with setbacks. We have begun recruit members for the next team and have begun showing them the goings on with the boat to ensure no future setbacks and hope that this will allow them to make up for our mistakes this past semester.