Homework Packaging Specifications and Design by jennyyingdi


									ECE 477                     Digital Systems Senior Design Project                      Rev 8/09

                Homework 4: Packaging Specifications and Design

Team Code Name: __Purdue Airbus_____________________________ Group No. _1____
Team Member Completing This Homework: __John-Taylor Smith_____________________
E-mail Address of Team Member: _smith214_____ @ purdue.edu

SCORE                                        DESCRIPTION
            Excellent – among the best papers submitted for this assignment. Very few
            corrections needed for version submitted in Final Report.
            Very good – all requirements aptly met. Minor additions/corrections needed for
            version submitted in Final Report.
            Good – all requirements considered and addressed. Several noteworthy
            additions/corrections needed for version submitted in Final Report.
            Average – all requirements basically met, but some revisions in content should be
            made for the version submitted in the Final Report.
            Marginal – all requirements met at a nominal level. Significant revisions in
            content should be made for the version submitted in the Final Report.
            Below the passing threshold – major revisions required to meet report
            requirements at a nominal level. Revise and resubmit.

ECE 477                        Digital Systems Senior Design Project                        Rev 8/09

1.0 Introduction
         The Purdue Airbus provides a unique challenge with regard to its package. The final
design will incorporate an autonomous flight controller, digital signal processor, GPS receiver,
wireless module, camera, and three servo motors. These components will be combined to fit
within a fuselage that measures three feet long by six inches wide. Packing efficiency will be
critical in order to prevent wasted space. Excessive waste could lead to an undesirable PCB
footprint that will not fit within the UAV.
         The use of the Airbus’ fuselage as the final package presents both advantages and
disadvantages. To its advantage, a separate package will not need to be designed or fabricated.
Conversely, the package will need to remain unaltered throughout the design process. The
various components must share a finite amount of space and electrical resources, while
maintaining an optimal level of performance and reliability.
         The second package design, which entails less rigid restrictions with regard to size, is the
ground station. Although important, this facet of the packaging solution is less design oriented
since it utilizes a stand-alone Intel Atom board that will remain stationary in a predictable

2.0 Commercial Product Packaging
         Until recently, commercial UAVs have had a limited presence in the public sector. Their
intended applications are tailored for private industry and government projects. These
reconnaissance planes combine high-performance and reliability; however, the cost of a modern
UAV restricts their availability. There are only a handful of commercially produced, personal
UAVs that offer similar capabilities. The Purdue Airbus shares a variety of features with these
commercial products, but its lower cost increases availability among individuals. Among the
commercially available products, the DraganFlyer [1] and the Predator Drone [2] illustrate a
variety of the possible features. Each of these options offer comparable performance in their
intended applications. While neither of these commercial products could be directly compared
with the Purdue Airbus, they serve as benchmarks. Their various features will be compared

2.1 Product #1
ECE 477                       Digital Systems Senior Design Project                         Rev 8/09

       The DraganFlyer’s package and design resembles that of a helicopter and not a plane, but
its primary functions are similar. As seen in Figure 6 in Appendix A, the DraganFlyer’s main
components are housed within a center hull located in the center of the aircraft. There are many
benefits to this design and these act as motivation for the packaging of the Airbus. The central
hull allows for balanced center of gravity, extremely important for anything that flies, as well as
easy access to all the components and the battery source that powers them. Luckily, the Airbus’s
hull is longer than that of the DraganFlyer, allowing for more storage room for components. The
only downside to this packaging design for both the Airbus and the DraganFlyer is that there is
limited room for storage, relatively speaking.

2.2 Product #2
       The Predator Drone closely resembles the Airbus in concept and packaging. There are
many features of the Drone that the Airbus will emulate in order offer a more robust package as
well as effect capabilities. First, the Drone is a lightweight, aerodynamic plane that allows for
longer flights due to features, as well as a sturdy design to protect the UAV in the event of a hard
landing. The Airbus’s foam core is not only extremely light weight, it is quite durable as well.
Next, the Drone features a long slender hull, as seen in Figure 7, that provides storage for all
necessary components while night diminishing any of the aerodynamic features of the plane. The
Airbus’s package emulates this design with its own slender hull with storage capacity large
enough to hold the PCB and all necessary components for unmanned flight.

3.0 Project Packaging Specifications
       The Airbus has a simple, yet restrictive design. The packing for the components required
to operate the Airbus is already determined due to the fact that the plane itself is the package.
Luckily, the plane has more than enough room to house these components. The overall length of
the plane is 3 feet long, with a wing span of 4 feet 10 inches (Figure 1). The fuselage of the
Airbus is 5.5 inches wide by 5 inches tall (Figure 2,4). These dimensions are deceiving in a way
due to the fact that the thickness of the foam decreases the area of the internal compartment for
the components. The internal dimensions of the hull are 3 inches tall by 4 inches wide by 1.8 feet
long. The size of this hull will be large enough to house all the components of the Aircraft
because they are all very small devices. The largest item needed to be store on the Airbus is the
battery packs. They will be located in the nose of the plane because this predetermined location
ECE 477                       Digital Systems Senior Design Project                         Rev 8/09

helps balance out the center of gravity of the plane while occupying the narrowest part of the hull
leaving the belly open for the PCB.
        In order to mount the components in the hull of the plane, very few tools are needed. The
bulk of the packaging process is designing and creating the package and since the Airbus is itself
a package, the majority of this process is bypassed. The remaining tasks is to mount these
components inside of the hull. The PCB board, autopilot board, and the batteries will all be
mounted inside this hull to prevent moving and shaking that could lead to wires or components
losing there connections. The PCB will have stand-offs on each corner that will anchor the board
to the inside of the plane. The autopilot board will be anchored in the ribs of the plane, securely
holding it down while the foam acts as a non-inductive padding barrier. The camera position will
be on the outside of the plane, embedded into the foam shell and mounted in to insure that it will
not fall off of the plane.
        Due to the limited number of parts to complete the package for the Airbus, the cost and
overall weight addition are both very minimal. As seen in the Packaging Specifications table in
Appendix B, the overall weight of the plane will be under four pounds, meaning that only
roughly one pound will be added to the initial weight of the aircraft. Also, the parts necessary are
very trivial and at max will cost around ten dollars, if not less, due to the ease at which they can
be procured.

4.0 PCB Footprint Layout
        There are four main components required to be on the PCB in order for the UAV to
operate correctly. For these main components to fit onto a PCB that can fit inside the hull of the
Airbus, they must have a relatively smaller footprint to provide maximum space efficiency.
        The first main component is the Blackfin Embedded Processor [3]. This is the largest
chip on the PCB with 176 pin, quad flat pack design. Though it has many pins, it has a surface
are of less than one square inch. The next component required for the PCB is the XBee Pro
wireless module[4]. This chip will be connected to the PCB through a breakout board with eight
pins. Like the Blackfin processor, the XBee has an overall surface are of less than one square
inch. The last main component required is the Ultra Low Power CMOS Static Ram [5]. This
device, used as extra memory for the DSP, has an overall area of .35 inches, making it the
smallest main component used on the PCB.
ECE 477                       Digital Systems Senior Design Project                         Rev 8/09

       There are a few other non-main components that will be placed on the board to ensure
proper operation. There will be three voltage regulators, camera connection headers, and a
battery connector, all of minimal size. Also, a SD card header on the board in order to store data
for the image processing. This device has a square are of a quarter on an inch.
       Overall, as an estimate the PCB for the Airbus will have dimensions of 2.25 inches by
2.75 inches. This will fit perfectly into the hull of the Airbus and provide extra space as well in
the event the board must be enlarged to house another electronic device.

5.0 Summary
       Creating the packaging for the Purdue Airbus’s control components is a simple task with
some important restrictions. Although the plane itself acts as a package for all of the
components, the predetermined size of the aircraft restricts and limits the amount of space
available for these components. With the simplicity of our design, and the availability of small,
powerful components, the hull of the aircraft serves as a more than adequate housing for all of
the necessary controls, microchips, and the PCB.
ECE 477                    Digital Systems Senior Design Project                    Rev 8/09

                                     List of References

[1]   Dragan Fly Innovations Inc., DraganFlyer X4 Product Page. [Online]. Available:

[2]   RC Airplane Kits, 4-Channel Predator UAV Drone. [Online]. Available:

[3]   Analog Devices Inc., “Blackfin Embedded Processor,”
            ADSP-BF531/ADSP-BF532/ADSP-BF533 Datasheet Rev. G, May 2010

[4]   Digi International Inc., XBee™/XBee-PRO™ OEM RF Modules Product Manual, May

[6]   ISSI, “Ultra Low Power CMOS Static Ram,” IS62WV51216BLL Datasheet, Dec. 2007.
ECE 477       Digital Systems Senior Design Project     Rev 8/09

          Appendix A: Project Packaging Illustrations

          Figure 1: Purdue Airbus (perspective view)
ECE 477   Digital Systems Senior Design Project   Rev 8/09

          Figure 2: Purdue Airbus (side view)

          Figure 3: Purdue Airbus (top view)
ECE 477    Digital Systems Senior Design Project   Rev 8/09

          Figure 4: Purdue Airbus (front view)

          Figure 5: Purdue Airbus (profile view)
ECE 477   Digital Systems Senior Design Project   Rev 8/09

               Figure 6: DraganFlyer X4

               Figure 7: Predator Drone
ECE 477                    Digital Systems Senior Design Project               Rev 8/09

                       Appendix B: Project Packaging Specifications
Materials List                               Velcro
                                             Padding (soft foam/bubble wrap)

Tooling Requirements                         Adhesive

Estimated Weight                             < 4.0 lbs (~3.7 lbs)

Estimated Unit Cost                          $10.00
ECE 477                  Digital Systems Senior Design Project                Rev 8/09

                         Appendix C: PCB Footprint Layout

 Figure 8: Prospective PCB footprint (63 mm x 70 mm) - components are drawn to scale,
                             image is not displayed to scale

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