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DRONE LANDING PAD
The landing pad is the primary function for the package being delivered to the dropbox. The landing pad should open when a drone is flown above it, close after the package has been dropped, support the weight of a common delivery drone, and protect the box from malfunctions/impacts from the drone.
The material planned to be used for the landing pad door is ½” exterior plywood comprised of multiple pine veneers. This material was chosen because it will be the best material to perform the outputs needed. First off, the material will be weatherproof. The term “exterior” is used in its name because it is built for repeated wetting and drying and long term exposure to weather. Second, the material originally used for roofing and the subground building has a span rating of 32/16. This means we will have to support the panel every 16 inches to support the weight of deck use. So the design of the panel itself incorporates two layers of the plywood glued together, one layer a solid piece and the other 4 evenly cut slices so that it is braced every 8 inches, check figure 8 and figure 9 for dimensions. Which makes the piece more than able to support the weight of a person.
Top view of landing pad platform. Drawn by Tyler Walls in Solidworks
DROPBOX LOCATION
The location and package accessibility is a large part of the success of the system itself. To ensure the package is delivered safely without damage or human interaction, the system must be situated in such a way that promotes ease of access for residents as well as the drones. The dropbox location on the top floor extruding to the roof provides the most satisfactory results. The roof location of the landing pad ensures the safest and fastest route for the drone, eliminating the risks of ground landings, attempting to land on the side of the building, as well as navigating through people, trees, and other buildings. The locker location on the top floor allows for consumer access without having to leave the complex to retrieve their package from a mail room or front desk. Finally, the location ensures security of the package for the consumer. Being located on the top floor isolates the dropbox from public access, keeping the area strictly residential and secure. The roof portion of the dropbox will be a 40x40 inch square extending down 5 inches into the level below. The top floor portion of the dropbox will be 12 feet high, 3 to 4 feet extending into the ceiling, 16 feet long and 10 feet deep. The location will also require 5 feet of room in front of each locker to ensure full range of motion of the door and ease of consumer access
SORTING MECHANISM
The sorting mechanism encompasses the main technology used to recognize the package and transport it safely to the appropriate locker. The tested prototype utilizes a color sensor to differentiate between packages, but there are significant limitations to this approach. The implemented dropbox would likely use a more sophisticated technology such as a barcode scanner or even direct communication with the drone to allow for each package to have a unique assignment to a designated safe. This way, when an item is ordered, that item is specially marked with a tracking number that corresponds to a locker, and upon delivery, the sorting mechanism can direct the package to the appropriate locker. Upon receiving the digital input of the recognition device, a computer will communicate with a series of motors to lower the package and rotate gates along a path in order to direct the package’s movement. These motors must be able to rotate to the appropriate position upon receiving computer input and they must be strong enough to withstand the impact of a box up that weighs five pounds, or the heaviest expected drone-delivered package. The acceleration of the box itself relies on gravity, and thus the sorting mechanism is comprised of a series of ramps. In order to reduce the amount of friction between the ramp and the package as well as ensure durability, the sorting mechanism ramps will be constructed of polished sheet metal. As packages are retrieved from their locker, an automated program can assign the next drone-ordered tracking number to that locker, once again initiating the sorting mechanism.
OUTER SHELL
The shell is water tight so that packages do not get damaged by the weather. Multiple people will be able to use the dropbox, and each person will have their own personal locker and padlock for the locker. The shell also includes walls in order to create partitions between each user’s locker. Some wires for the charging station and sorting mechanism will also be connected to the inside of the shell. The outer shell will be made out of 0.5’’ thick plywood coated with wood sealer to ensure the dropbox is sturdy and waterproof. The lockers will have hinges made out of steel, and the locking mechanism will simply be a padlock and two pieces of steel, one attached to the locker door and the other attached to the outside of the shell. Two rows of five lockers will be available for customers to use. Due to the sorting mechanism being a sloped object, the heights of each locker’s wall will not be the same as the height of the dropbox. Each locker will by 2.5’ by 2.5’ by 2.5,’ illustrated in figure 2. The landing pad will be attached to the opening of the shell, which is the top left in figure 2. The sorting mechanism will be inserted about a foot down from the top of the dropbox, and will end at the wall of the last locker. The shell and walls will be assembled by using 90 degree, 1” by 1”, zinc plated corner braces and screws. These braces do not rust, and are cost effective at $0.15 each. The lockers will be able to swing open by attaching two hinges to the locker doors and the outer shell, and the locking mechanism will be located approximately one foot from the ground shown in figure 2. Three hinges is unnecessary, and one hinge will result in unstable lockers, so two hinges will be used. The hinges will be made out of satin nickel, and screwed into place into the wood. The hinges are cost effective at $1.74 each and will not get damaged from water, making them ideal for the lockers.