Designing the Opening Component

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There are many aspects that need to be considered when developing the mechanical system.

Planning

Completion	Due Date *a little flexible	Stage
	29-Sept	Answered all Research Questions
	29-Sept	List of Requirements the opening should fulfill
	29-Sept	Set Specifications/Facts for tote & speed
	1-Oct	Mechanisms and Design Decisions Done to get to final concept
	6-Oct	Detailed Sketch(es) of Opening
	6-Oct	Description of how it works & how to build

Facts

KS-OpeningP1-27-09

Drone Tote	Height	Width	Depth	Weight
Average	12 cm	15 cm	26 cm	1.5 kg max 2.3 kg

_{Specs were estimated from looking at the Amazon Prime Air video since no real dimensions could be found, currently.}

Tote has barcode located in bottom right corner of the tote on both the front and back face, simplifies orientation problem.

Totes expected to be handled p/day: 20 max
Time Spent handling a tote: 1 minute

Problem Description

Goal: The goal in this stage of the system is to receive a package from a drone, have it oriented in the appropriate position for further processing, and get it to the next stage of delivery.

KS-OpeningP2-27-09

Factors/Constraints

Environmental Factors	Dynamic Factors	Technical Factors
Rain	Birds	Waterproofing?
Snow	Bugs	Moisture Resistance?
Debris		Temp. affects on function?

Tasks / Functions

Task/Function	Description
Positioning	Drone+/or Package reaches the correct place for dropping the package or entering the system
Identification	package+/or drone needs to be identified by the system so that it can further handle the package
Accuracy	drone landing/dropping of the package should be accurately placed in the landing zone
Speed	The rate at which a package should be handled to the next stage of the system
Size of Landing Zone	The size may effect accuracy of package dropping (want to make this as large as possible)
Flight Path Problem	How many DoF does the drone have to approach the opening?

Assumptions:

• Drone has Obstacle Detection to avoid objects in its way

Research Questions

Identification

Question: What kind of identification methods are there and how do they work?

• Radio Frequency ID (RFID) - makes use of wireless electromagnetic fields to transfer data. It allocates tracking and identification of tags which are attached to items. This has been used in many different areas: Access Control for Hotel Rooms, Transportation and logistics in a distribution center, Track and trace of package deliveries.
  • How it works: To make use of this identification methods it consists of two parts: a Tag and a Reader. The tag has the identification which can be transmitted. The reader sends a signal to the tag & then reads its response. The type of RFID system that is used is dependent on the tags and readers chosen to use.
  • Used in Real Life: Drone Tracks Steel Products in Storage Yard The drone is equipped with an RFID reader and steal bundles have the tags. Daily this drone hovers over various areas, reads tags and couples its own GPS location to this information and feeds it to a PC where the company keeps track of inventory.
    • This could possibly be used on the platform design to get the package identified and then couple a cubby number to the package as it further proceeds through the system.
  • RFID Systems can: Keep count of stock through capturing all tags in a given areas & comparing them to a previous inventory position
    • This could solve keeping track of empty and full cubbies as well.
  • Also good to note that RFID tags can be rewritten/relabeled after use

(See | RFID Wiki for more information)

• Barcode Scanning - makes use of a barcode and scanning devices that reads the barcodes. Barcodes are read via a light sensor which translates "optical impulses" into electrical ones, which decodes into the barcode's contents. Kinds of bar-code scanner that may be appropriate for our system.
  • Omni-Directional Fixed Position Scanner - Can read poorly printed, wrinkled, or even torn barcodes. Often used in logistics to identify trays or pallets that need distribution to specific locations, or used in supermarkets. This type of scanner can be oriented in a position to read the barcodes off the package.
  • Looking at possible barcode scanners that can be bought and their specifications I stumbled up Leuze Electronic. There I found a vast array of barcode scanners and detail in how they could be used. A Single Scanner, just 1 positioned however we want, could scan at high rates (industrial) but could only read a barcode from a specific orientation. A MPSi System, however, allowed the barcode to be read from any orientation. This was done by use for 2-3 scanners located in various positions. The cost of this kind of system, was definitely more pricey. Also to be noted is that each of these scanners require external power sources, or otherwise batteries that need replacement often.
  • Furthermore, there are various types of barcodes: QR code, Universal Product Codes etc. Any of these would be appropriate for our system.
    

(See | Barcode Reader wiki for more information.)

What this research contributes to the design of this component:
From the research above, the RFID would be the better solution for the system:

1. because it allows identification to be a continual process instead of requiring check points for scanning
2. because it allows for re-writable totes, instead of having to sticker on a new barcode for every package
3. because it creates more DoF in package orientation because a single receiver can located somewhere in the system, rather than placement of a scanner where the package has to pass by in the appropriate orientation

• Minor Considerations for the RFID: Security of the RFID/Interference with the RFID System

Orientation / Location Finding

Question: What kind of orientation methods are there to position robots/carts/etc. and how do they work?

• Parking Sensors - signal the driver when he/she is getting close to an obstacle.
  • How it Works: Sensors send out acoustic pulses, with a control unit measuring the return interval of each reflected signal and calculating object distances
  • Real Life Scenario: Automatic Parking Systems - Sensors installed on the bumpers act as transmitters and a receivers. These sensors send a signal that will be reflected back when it encounters an obstacle near the vehicle. Then, the returning time signals are used to determine the position of obstacles. The car will detect the parking space size and distance from the roadside, then drive the car into the parking space. Volvo Autonomous Parking Video

• Wireless Call & Receiver Units (PatentUS7636621) - Makes use of a directional wireless reception unit on a device. It can receive a radio wave guidance from a call unit and then move toward the unit on basis of intensity and direction of the signal.

• Visual Tracking - Through use of a tracking sensor and a target (symbol or object that device is set to detect) a system can align itself appropriately with the target. There are some difficulties with the feedback loop that should be addressed.
  • How it Works: Alignment through rotation is completed by calculating what angle the device needs to turn in order to align with the target. A visual image sent to the system can allow calculation for the answer of degrees needed to move & a gyro could assist in sensor feedback to know how far the device has turned already. Distance measurement and alignment through x-y movement is can be done by programming a set distance one can move and comparing it to the status of the location of the target.

What this research contributes to the design of this component:
From the research above it can be noted that there are means to get the drone to the landing platform as well as make it possible to align a certain way before dropping off the package. The Wireless Call & Receiver Units would be a good use of making the drone find the landing platform because the call unit signals can be sent when the drone is detected in proximity. Also the visual tracking could be used to align the drone in a certain direction on the platform. (If that is really necessary is dependent on the identification method used.) The complications with the visual tracking, however, could be that the alignment target may be covered by something which prevents detection. So solutions would have to be addressed for that.

Birds & Environmental Factors

Question: What are possible ways to keep birds off a platform?
To keep birds away, one can use visual deterrents, audio, scents etc. (Installing fake owls, spray designated areas with certain scents etc.) The issues are if birds can detect the owl is fake, they will come back and certain scents need to be reapplied regularly. Moving objects do well in keeping birds out of vicinities.
Question: What are some simple solutions to prevent snow/rain accumulation on a raised platform?

• Have a grated platform allows drainage capabilities.
• Have a slanted platform allows the snow and rain to slide away due to gravity
• Spraying with Snow/Ice Repellent

What this research contributes to the design of this component:
To address the environmental factors for our system, it is good to know that spraying with snow/ice repellent is quite effective in the winters. Although this will cause a hassle to get maintenance on the roof, it will make sure the system continues to function properly. Also to address the birds, if we have moving parts on our system, we already have a deterrent for the birds. Other means of repelling become less effective over time or have to be continually maintained.


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Ideas

• 

  KS-OpeningP3-27-09
  Sloped Platform & Door Ideas

• 

  KS-OpeningP4-27-09
  Flat Platform & Debris Ideas

• 

  KS-OpeningP5-27-09
  Orientation Idea & Conveyor Idea

• 

  KS-OpeningP6-27-09
  Funnel & Door Ideas

Drone Drop Zone

Sloped Platform

Labels: Drone Drop Zone
See page3 in gallery above for sketch.

How it Works	Pros	Cons
As the name suggests, this set-up has a platform that is sloped with alignment to the roof. The slope allows for the package to be dropped and travel down with gravity towards the opening of the chimney. Also this system has a wiper which pushes the package in alignment after dropping. To make sure the package does not fall off the platform, there are guides.	Wiper can be used to clean off debris & snow.	Drone flight path slightly obstructed due to wiper & guides
	Allows wide land/drop zone for the drone.	May look odd on buildings with flat roofs
	Drone can be oriented, but is not necessarily required b/c system aligns package after drop

• See door mechanisms that could couple to this component to bring package into the system
• See orientation mechanisms that could couple to align package

Flat Platform

Labels: Drone Drop Zone
See page4 in gallery above for sketch.

How it Works	Pros	Cons
This set-up has a platform that is flat and makes the use of two wipers. One in the x direction and one in the y direction, which will be used t align the package accordingly with the opening of the chimney. Guides prevents the package from falling off the platform.	Gets package oriented and to location	Flat less effective than slanted
	Allows for big area land/drop zone	Drone flight path slightly obstructed by wipers & guides
	Drone can be oriented, but is not necessarily required b/c system aligns package after drop

• See door mechanisms that could couple to this component to bring package into the system
• See orientation mechanisms that could couple to align package

Conveyor

Labels: Drone Drop Zone See page5 in gallery above for sketch.

How it Works	Pros	Cons
Similar to the other two platforms above. This idea has a large landing platform but has a continual moving conveyor located on one side. A wiper pushes the package onto the grated conveyor which leads the package to the chimney.	Continual movement of conveyor limits debris and snow accumulation	Maintenance very important
		Possible noise issues?

• See door mechanisms that could couple to this component to bring package into the system
• See orientation mechanisms that could couple to align package

Funnel

Labels: Drone Drop Zone
See page6 in gallery above for sketch.

How it Works	Pros	Cons
This is a large low gradient funnel. The drone drops the package off somewhere in the funnels area and the package then slides down to the chimney opening via gravity.	Mechanically Simple	Snow and other environmental factors also funnel to the chimney opening.
	Drop area is large	Package may be too light to be affected by the gradient?

• See door mechanisms that could couple to this component to bring package into the system
• See orientation mechanisms that could couple to align package

Covered Funnel

Labels: Drone Drop Zone with Door Mechanism
See page6 in gallery above for sketch.

How it Works	Pros	Cons
This is a large low gradient funnel. The drone signals to the system that it is approaching and the funnel's cover opens. Then the drone drops the package off somewhere in the funnels area and the package slides down to the chimney opening via gravity.	Addresses the environmental factors	Package may be too light for gradient
	Large area for dropping	Funneling package may create noise?

• See door mechanisms that could couple to this component to bring package into the system
• See orientation mechanisms that could couple to align package

Door Mechanisms

Garage Door

Labels: Door Mechanism
See page4 in gallery above for sketch.

How it Works	Pros	Cons
This is a scaled down version of the garage door/storage door we use in real life. It would cover the entry to the chimney and roll up on the side when signaled to open for a package.	Simple mechanism	Could be heavy or not durable
	Takes care of snow/rain that accumulates by rolling up and moving it away.	Could get caught up in itself when rolling up

Double Doors

Labels: Door Mechanism
See page6 in gallery above for sketch.

How it Works	Pros	Cons
One set flips up and outward to knock off any snow/debris and allow package inside.	Handles environmental factors	Doors flipping may hit something
		Malfunction could cause package to be flipped off the roof.

Double Flaps

Labels: Door Mechanism
See page6 in gallery above for sketch.

How it Works	Pros	Cons
Hereby there are two sets up doors. 1 set flips up and outward to knock off any snow/debris and another set of doors that collapses inwards to allow the package through. These occur after each other to ensure nothing else gets into the system.	Extra precaution for bird/other external factors	Doors flipping to the inside take up space
		Malfunction could cause package to be flipped off the roof.
		Doors flipping out may hit something

Folding Doors

Labels: Door Mechanism
See page6 in gallery above for sketch.

How it Works	Pros	Cons
One set of doors that folds accordion style to the side which allows the package to proceed to the next stage.	Makes space the doors take up small when open.	Could allow environmental factors to fall inside.
		Mechanically more difficult

Orientation

RF & Beacon

Labels: Orientation
See page5 in gallery above for sketch.

How it Works	Pros	Cons
This is a possible solution for orientation & identification of the package. Through a radio frequency a drone can signal to the delivery system that it is in range (or vice versa). Over this RFID information can be sent about the size and location of the drone drop zone so that the drone can find it. Once hovering over it, the drone can then align itself with a light beacon located at a point on the platform.	Can transfer information about the package over the RFID as well	Beacon can be blocked by environmental obstacles
	Allows specification of drone platform location and size of drone zone	Possible hacking?

Contrast Symbol

Labels: Orientation
See page5 in gallery above for sketch.

How it Works	Pros	Cons
This is a possible solution for orientation & identification of the package. Through a symbol painted on the drone zone platform, the drone can perceive the contrast and orient itself accordingly to the symbol.	Simple Solution of painting a symbol	Paint can fade
	Allows specification of drone platform size on basis of symbol	Not a method to help find the platform

Requirements

Functional	Process	External
The component should be able to accept a package from a drone.	The component should be able to identify the package & designate a cubby location.	The delivery drones must be capable of moving to an exact location in x, y and z direction.
The component should be able to get the package to the next phase of delivery.	The component should complete package retrieval within 30 seconds.	The delivery drones must have a Wifi Signal receiver to retrieve platform location information
The component should have a way to handle debris & weather complications.	The component should communicate with the delivery drone to provide location information.	The delivery drones should be able to calculate approach and positioning
The component should be able to report malfunction.	The component should know when a package is on the platform and is clear to proceed.

Design Selection

Drop Zone - Flat with Wipers to maneuver package to chimney also grated to address some environmental factors
Door - Garage door system
Identification - RFID tags
Orientation - Radio signal & possibly visual tracking

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