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‎Blogs/MechE/eebox.html

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@@ -124,26 +124,46 @@ <h2 class="entry-title">
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</div> -->
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<div class="entry-content">
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<p>
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One of the first tasks our team worked on was buoy
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detection. Most of the navigation courses in Roboboat
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require us to identify buoys and then figure out how to
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navigate them. Using a ZED camera, we developed the
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following algorithmic steps to properly identify buoys
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on the course:
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The purpose of a custom electronics box is to provide a lightweight, accessible, easily modifiable, cool (temperature-wise), splash-proof housing for Fish ‘N Ships’ electrical components.
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</p>
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<p>Performs erosion with a segmentation kernel</p>
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<p>
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Performs dilation with the same segementation kernel
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<p><i>Design 1:</i></p>
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<p style="text-indent: 50px;">The initial design of the EE box focused on accessibility, modularity, and thermals. It consisted of an ⅛”
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aluminum base, ⅛” acrylic walls, removable faceplates, a large “land” lid, and smaller “water” lids. This version of the box condensed the boat’s
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sensors and electronics into a single sub-assembly--i.e., its “brains”--that could be removed and tested independent of the hulls. The electronics
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were designed to mount to slightly elevated acrylic pegboards (elevated for subterranean wire management). Thermals were managed passively by aluminum
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“sleeves” that wrapped completely around the hulls and made direct contact with the box’s aluminum base. Overall footprint was roughly 32”x16”x6.5”
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(not counting the height of the sensor mast).
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</p>
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<p>Converts the image to HSV</p>
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<p>
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Gets the mask for each color range we are looking
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at(red, green, yellow)
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<img src="../../Pictures/Blogs/eebox1.png" style="display: block; margin-left: auto; margin-right: auto;width: fit-content;">
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<p style="text-indent: 50px;">The second iteration of the box was driven by a single design requirement the first design failed to meet: weight.
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The original design weighed ~13 lbs, roughly 12% of the team’s weight budget at the time. This egress prompted a spirited discussion of the
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necessity of a custom EE box--off the shelf options are cheaper, require less manpower (from the team at least), are rated to depths well
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beyond the design requirements of the box, and commonly used by RoboBoat teams. Modifying such boxes--while inelegant--is neither costly
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nor difficult, though it does make the box’s original pressure rating irrelevant. The question thus became: can we manufacture a box that
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offers a better weight to volume ratio than the leading alternative? And would it be worth the cost? We decided there was a high probability
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we could--and that the cost was more than justified by the learning experience.
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</p>
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<p>
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Generates a bounding box for each disjoint blob in the
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color range mask
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<p><i>Design 2:</i></p>
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<p style="text-indent: 50px;">Design two features the elevated peg boards and removable faceplates of the first design, only this time they’re
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compressed into a footprint roughly a third the size (12”x16”x8”). To account for this compressed footprint the pegboards were elevated ~4” off
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the base (enough room to rotate the average human hand comfortably)--opening up a second layer for mounting components. The focus on weight reduction
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meant the old aluminum base with its heat finned cooling system was a non starter.. Fabric--engineered by a fashion industry focused on breathability,
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water resistance, and weight--was the obvious replacement. The new box was constructed almost entirely out of an ⅛” plywood frame, and the lid draped
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in PolyUrethane Laminate--a lightweight, durable, water resistant cloth commonly used for DIY diapers. Finally, fans, protected by 3D printed shrouds,
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were added for increased airflow.
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</p>
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<img src="../../Pictures/Blogs/eebox2.png" style="display: block; margin-left: auto; margin-right: auto;width: fit-content;">
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<p><i>Current Design:</i></p>
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<p style="text-indent: 50px;">The current design retains many of the core innovations of the previous two--including the elevated peg boards,
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fabric lid, and removable faceplates. The primary driver of this iteration was usability feedback from the EE team: a self locating pin was added
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to make aligning the lid easier when latching the box shut and to prevent water from pooling during rainy tests; the number of mounting screws per
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faceplate was doubled to prevent water from entering the box when rogue waves swept over the deck; 1/32” aluminum L brackets were fastened to the edges
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of the acrylic pegboards to prevent the previous bowing/flexing/swaying behavior that made mounting components to the pegboards difficult; compliant hooks
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were added to keep the latches in the “upright” position while lowering the lid; and the Jetson was mounted on L-bracket stand-offs to allow for rapid
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insertion and removal from the box. Once the wooden seams of the base were caulked with a polyether adhesive the box proved watertight to 16cm (at which
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point water entered via the fan out take), well above design spec.
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</p>
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<img src="../../Pictures/Blogs/eebox3.png" style="display: block; margin-left: auto; margin-right: auto;width: fit-content;">
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</div>
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</main><!-- End #main -->
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‎Blogs/MechE/hulls.html

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</ul>
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</div> -->
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<div class="entry-content">
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<p>
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One of the first tasks our team worked on was buoy
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detection. Most of the navigation courses in Roboboat
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require us to identify buoys and then figure out how to
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navigate them. Using a ZED camera, we developed the
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following algorithmic steps to properly identify buoys
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on the course:
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</p>
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<p>Performs erosion with a segmentation kernel</p>
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<p>
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Performs dilation with the same segementation kernel
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</p>
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<p>Converts the image to HSV</p>
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<p>
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Gets the mask for each color range we are looking
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at(red, green, yellow)
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</p>
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<p>
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Generates a bounding box for each disjoint blob in the
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color range mask
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</p>
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<p style="text-indent: 50px;">Our new vehicle, Fish ‘N Ships, features a catamaran design due to its stability and low drag
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characteristics. In the initial design, we placed the battery boxes within the hulls to lower the center of mass, decided on
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ammo boxes to store the batteries for fireproofing, and used foam as the main material of the hulls since it would be less likely
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to sink if the hulls were punctured. However, the final product turned out to be 36lbs, which was much higher than we expected,
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since we were trying to keep the overall weight of the vehicle under 70lbs.
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</p>
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<img src="../../Pictures/Blogs/hulls1.png" style="display: block; margin-left: auto; margin-right: auto;width: fit-content; margin-bottom: 30px;">
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<p style="text-indent: 50px;">Thus, we began a new round of design with more specific design requirements and tried different
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manufacturing techniques. While we still planned on using foam and sealing it with epoxy and fiberglass, we utilized vacuum
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bagging technology instead of doing hand layups, since vacuum bagging can spread the epoxy more evenly across the surface, resulting
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in less layers (and weight) than manual techniques. We also decided to shorten the hulls to make the boat smaller, which would also
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help cut down the weight and make the boat easier to transport. Finally, instead of using ammo boxes, which contributed significantly
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to the weight, we opted for tupperware, since they worked well in waterproofing the batteries and were also very lightweight. The current hulls
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are only 12lbs total. They are four feet in length, and the entire boat can be easily carried by two people.
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</p>
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<img src="../../Pictures/Blogs/hulls2.png" style="display: block; margin-left: auto; margin-right: auto;width: fit-content;">
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</div>
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</main><!-- End #main -->
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‎Blogs/MechE/propulsion.html

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</ul>
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</div> -->
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<div class="entry-content">
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<p>
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One of the first tasks our team worked on was buoy
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detection. Most of the navigation courses in Roboboat
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require us to identify buoys and then figure out how to
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navigate them. Using a ZED camera, we developed the
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following algorithmic steps to properly identify buoys
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on the course:
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</p>
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<p>Performs erosion with a segmentation kernel</p>
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<p>
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Performs dilation with the same segementation kernel
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</p>
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<p>Converts the image to HSV</p>
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<p>
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Gets the mask for each color range we are looking
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at(red, green, yellow)
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</p>
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<p>
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Generates a bounding box for each disjoint blob in the
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color range mask
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<p style="text-indent: 50px;">Our previous vehicle only had two thrusters in the rear, which meant we didn’t have strafing or station
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keeping abilities. Thus, for Fish ‘N Ships, it was very important to us to use an x-drive configuration (two thrusters in the front
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and two thrusters in the back of the hulls). This allowed our new vehicle to strafe and station-keep with ease. However, we didn’t know
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the best angle to mount the thrusters, and we wanted to keep it adjustable so that we can test out the best configuration. Therefore,
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we designed an attachment on the bottom of the hulls that had holes in 22.5 degree increments, to allow us to easily attach the thrusters
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in different positions.
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</p>
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<img src="../../Pictures/Blogs/propulsion.png" style="display: block; margin-left: auto; margin-right: auto;width: fit-content;">
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<p style="text-indent: 50px;">Another design consideration we had in mind was to add some sort of protection to the thrusters. In the past,
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we could not set the vehicle down without propping it on a platform since the thrusters protruded from the hulls. This made it difficult to
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transport and test the boat. Therefore, our team decided to add some thruster cages to allow us to set the boat on the ground.
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</p>
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<p style="text-indent: 50px;">In our initial design, we mounted two U-bolts for each thruster, but we quickly realized that the U-bolts
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were quite heavy, contributing to 10% of the overall vehicle weight. Therefore, we considered different materials and geometry to reduce
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the weight. For material, we decided to SLA 3D print using Formlabs Tough 2K resin. As for geometry, two different designs were considered.
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The first design weighed a total of 2.4 lbs, and the second design has a total weight of 4.15 lbs. We ended up choosing the first design in
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consideration of weight restraints. However, we wanted to make sure that the first design can still withstand a reasonable amount of force,
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so we verified with FEA performed on OnShape and physical tests. The results showed that each cage could support over 150lbs, which is more
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than sufficient for our design, and now, the cages only contribute to 4% of the total weight.
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</p>
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<img src="../../Pictures/Blogs/thrustercages.png" style="display: block; margin-left: auto; margin-right: auto;width: fit-content;">
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</div>
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</main><!-- End #main -->
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‎Blogs/MechE/sensormast.html

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</ul>
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</div> -->
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<div class="entry-content">
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<p>
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One of the first tasks our team worked on was buoy
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detection. Most of the navigation courses in Roboboat
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require us to identify buoys and then figure out how to
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navigate them. Using a ZED camera, we developed the
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following algorithmic steps to properly identify buoys
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on the course:
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<p style="text-indent: 50px;">Our sensor mast provides a stable platform with an unobstructed field of view for the ZED camera and LiDAR to fully utilize the sensors’
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capabilities. Our initial design consisted of a central PVC pipe with FDM printed mounts for the LiDAR, ZED, and various other sensors. The pros of
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this design was that it was easy/quick to manufacture; however, after thorough testing, we found that the mast exhibited a low-frequency swaying
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behavior when the boat was on the water. This interfered with the perception performance of our autonomy system, so we iterated on the design.
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The current design features three mounting points instead of two, contributing to a much stabler platform. It is made of ⅛” aluminum box tube
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braised into a rigid frame, and it features adjustable height vibration dampers to prevent the swaying behavior.
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</p>
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<p>Performs erosion with a segmentation kernel</p>
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<p>
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Performs dilation with the same segementation kernel
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</p>
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<p>Converts the image to HSV</p>
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<p>
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Gets the mask for each color range we are looking
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at(red, green, yellow)
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</p>
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<p>
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Generates a bounding box for each disjoint blob in the
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color range mask
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<img src="../../Pictures/Blogs/sensormast1.png" style="display: block; margin-left: auto; margin-right: auto;width: fit-content;">
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<p style="text-indent: 50px;">The current design features three mounting points instead of two, contributing to a much stabler platform. It is made
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of ⅛” aluminum box tube braised into a rigid frame, and it features adjustable height vibration dampers to prevent the swaying behavior.
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</p>
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<img src="../../Pictures/Blogs/sensormast2.png" style="display: block; margin-left: auto; margin-right: auto;width: fit-content;">
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</div>
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</main><!-- End #main -->
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<div class="col-lg-2 col-md-6 footer-links">
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<h4>Useful Links</h4>
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<ul>
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<li><a href="../index.html">Home</a></li>
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<li><a href="../about.html">About us</a></li>
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<li><a href="../team.html">Team Members</a></li>
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<li><a href="../contact.html">Sponsors</a></li>
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<li><a href="../../index.html">Home</a></li>
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<li><a href="../../about.html">About us</a></li>
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<li><a href="../../team.html">Team Members</a></li>
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<li><a href="../../contact.html">Sponsors</a></li>
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</ul>
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</div>
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‎Blogs/blog-mechE.html

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<div class="container pt-5 pb-5">
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<div class="row content justify-content-center" style="text-align:center">
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<h2>Mechanical Engineering</h2>
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<h4>Click on the cards below to read more about our subsystems. </h4>
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<div class="row" data-aos="fade-up">
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<div class="col-lg-4 col-sm-4 py-2">
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<a href="MechE/hulls.html" class="card-overlink">
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<div class="card shadow" style="width: 100%">
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<img
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src="../Pictures/Blogs/buoydetection.png"
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src="../Pictures/Blogs/hulls2.png"
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class="card-img-top"
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alt="..."
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style="max-height: fit-content; width: auto; margin: 30px 30px 10px 30px; display: block;"
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/>
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<div class="card-body pb-4">
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<h4 class="card-title">Hulls</h4>
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<p class="card-text">
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Read More
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Foundation of our boat
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</p>
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</div>
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</div>
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<a href="MechE/propulsion.html" class="card-overlink">
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<div class="card shadow" style="width: 100%">
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<img
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src="../Pictures/Blogs/propulsion.png"
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class="card-img-top"
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alt="..."
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style="max-height: fit-content; width: auto; margin: 30px 30px 10px 30px; display: block;"
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/>
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<div class="card-body pb-4">
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<h4 class="card-title">Propulsion/Thruster Cages</h4>
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<p class="card-text">
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Read More
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Driving force of our boat
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</p>
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</div>
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<a href="MechE/eebox.html" class="card-overlink">
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<div class="card shadow" style="width: 100%">
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<img
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src="../Pictures/Blogs/eebox3.png"
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alt="..."
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style="max-height: fit-content; width: auto; margin: 30px 30px 10px 30px; display: block;"
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/>
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<div class="card-body pb-4">
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<h4 class="card-title">EE Box</h4>
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<p class="card-text">
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Electronics protector
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</p>
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</div>
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</div>
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<a href="MechE/sensormast.html" class="card-overlink">
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<div class="card shadow" style="width: 100%">
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<img
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src="../Pictures/Blogs/sensormast2.png"
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class="card-img-top"
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style="max-height: fit-content; width: auto; margin: 30px 30px 10px 30px; display: block;"
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/>
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<div class="card-body pb-4">
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<h4 class="card-title">Sensor Mast</h4>
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<p class="card-text">
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Read More
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Mounting point for sensors
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</p>
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</div>
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<a href="MechE/mechanisms.html" class="card-overlink">
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<div class="card shadow" style="width: 100%">
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<img
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src="../Pictures/Blogs/comingsoon.jpg"
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style="max-height: fit-content; width: auto; margin: 30px 30px 10px 30px; display: block;"
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/>
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<div class="card-body pb-4">
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<h4 class="card-title">Mechanisms</h4>
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<p class="card-text">
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Allow for robotic functions
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</p>
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</div>
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</div>

‎Pictures/Blogs/comingsoon.jpg

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‎Pictures/Blogs/eebox1.png

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‎Pictures/Blogs/eebox2.png

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‎Pictures/Blogs/eebox3.png

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‎Pictures/Blogs/hulls1.png

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‎Pictures/Blogs/hulls2.png

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‎Pictures/Blogs/propulsion.png

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‎Pictures/Blogs/sensormast1.png

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‎Pictures/Blogs/thrustercages.png

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