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RockSat-C 2012PDR
Team NamePreliminary Design Review
University/InstitutionTeam Members
Date
1
RockSat-C 2012PDR
User Notes
• You can reformat this to fit your design, but be sure to cover at least the information requested on the following slides
• This template contains all of the information you are required to convey at the PDR level. If you have questions, please don’t hesitate to contact me directly:
[email protected] 720-314-3552
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RockSat-C 2012PDR
User Notes
• This template is based on an example mission to show the level of detail needed for your “preliminary design”
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RockSat-C 2012PDR
Purpose of PDR
• Confirm that:– Science objectives and required
system performance have been translated into verifiable requirements
– Payload Design: to specifications from requirements, can be met through proposed design (trade studies)
– Project risks have been identified, and mitigation plans exist
– Project management plan is adequate to meet schedule and budget
– Project is at a level to proceed to prototyping of high risk items
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gnurf.net
RockSat-C 2012PDR
PDR Presentation Content
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• Section 1: Mission Overview– Mission Overview– Organizational Chart– Theory and Concepts– Concept of Operations– Expected Results
• Section 2: System Overview– Subsystem Definitions– Critical Interfaces (ICDs?)– System Level Block Diagram– System/Project Level Requirement Verification Plan– User Guide Compliance– Sharing Logistics
RockSat-C 2012PDR
PDR Presentation Contents
• Section 3: Subsystem Design– Subsystem A (SSA) (i.e. EPS)
• SSA Block Diagram• SSA Key Trade Studies (1 – 2?)• Subsystem Risk Matrix/Mitigation
– Subsystem B (SSB) (i.e. STR)• SSA Block Diagram• SSA Key Trade Studies (1 – 2?)• Subsystem Risk Matrix/Mitigation
– Etc., Etc…
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jessicaswanson.com
RockSat-C 2012PDR
PDR Presentation Contents
• Section 4: Prototyping Plan– Item “A” to be Prototyped– Item “B” to be Prototyped– Etc., Etc…
• Section 5: Project Management Plan– User’s Guide Compliance, Sharing– Org Chart– Schedule– Work Breakdown Structure– Budget
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RockSat-C 2012PDR
Mission OverviewName of Presenter
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RockSat-C 2012PDR
Mission Overview
• Mission statement• Break mission statement down into
your overall mission requirements• What do you expect to discover or
prove?• Who will this benefit/what will your
data be used for?
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RockSat-C 2012PDR
Theory and Concepts
• Give a brief overview of the underlying science concepts and theory
• What other research has been performed in the past?– Results?
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RockSat-C 2012PDR
Concept of Operations
• Based on science objectives, diagram of what the payload will be doing during flight, highlights areas of interest
• Example on following slide
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RockSat-C 2012PDR
Example ConOps
t ≈ 1.3 min
Altitude: 75 km
Event A Occurs
t ≈ 15 min
Splash Down
t ≈ 1.7 min
Altitude: 95 km
Event B Occurs
-G switch triggered
-All systems on
-Begin data collection
t = 0 min
t ≈ 4.0 min
Altitude: 95 km
Event C OccursApogee
t ≈ 2.8 min
Altitude: ≈115 km
End of Orion Burn
t ≈ 0.6 min
Altitude: 52 km
t ≈ 4.5 min
Altitude: 75 km
Event D Occurs
Altitude
t ≈ 5.5 min
Chute Deploys
RockSat-C 2012PDR
Expected Results
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• This is vital in showing you understand the science concepts
• Go over what you expect to find– Ex. What wavelengths do you expect to
see? How many particles do you expect to measure? How well do you expect the spin stabilizer to work (settling time?)? How many counts of radiation? etc
RockSat-C 2012PDR
System OverviewName of Presenter
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RockSat-C 2012PDR
System Level Block Diagram
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Buck Converter
Boost Converter
uController
WFF P
ower
InterfaceW
FF Telem.
Interface
Motor Controller
EPS
DEPPM
Photomultiplier
STR
Wallops PT
Interfaces
Low Voltage
High Voltage
Data/Control
Legend
• Show a full system of your subsystems, and the connections between them
RockSat-C 2012PDR
System Design – Physical Model
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MEPO Board
AVR Board G-Switch
Battery
Accelerometer
DetectorWFF Door Piece
Mounting Flange
RockSat-C 2012PDR
That was a BAD PHYSICAL MODEL!
• Why? Because you must have DIMENSIONS and UNITS!
• Remember, this is a preliminary design, so the design doesn’t have to be perfect or final– But still have labels, dimensions, and
units
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RockSat-C 2012PDR
Design in Canister (preliminary)
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Where are the dimensions?!
RockSat-C 2012PDR
System Concept of Operations
• Here, include a diagram and a step by step of your data collection process, or major activities happening in your payload– If you are collecting data, show/discuss
when the data will be available, how it’s collected, and where it gets sent
– If you have moving parts, be sure to include a simplified timeline of how things are happening along with the data collection
• This slide must be included
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RockSat-C 2012PDR
Critical Interfaces
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• At the PDR level you should at minimum identify critical interfaces. The following is an example of types of interfaces you might have, and how the interface between two systems might be designedInterface Name Brief Description Potential Solution
EPS/STRThe electrical power system boards will need to mount to the RockSat-X deck to fix them rigidly to the launch vehicle. The connection should be sufficient to survive 20Gs in the thrust axis and 10 Gs in the lateral axes. Buckling is a key failure mode.
Heritage shows that stainless steel or aluminum stand-offs work well. Sizes and numbers required will be determined by CDR.
PM/STRThe photomultiplier will need to mount to the RockSat-X deck rigidly. The connection should be sufficient to survive 20Gs in the thrust axis and 10 Gs in the lateral axes. Most likely, the PM will hang, and the supports will be in tension.
A spring and damper support will need to be developed. The system should decrease the overall amplitude of vibration no less than 50%.
DEP/STRThe deployment mechanism must rigidly connect to the RockSat-X deck. The actuator has pre-drilled and tapped 8-32 mounts.
8-32 cap head screws will mount the deployment mechanism to the plate. The screws will come through the bottom of the plate to mate with the DEP system.
DEP/EPSThe deployment mechanism has a standard, male RS-232 DB-9 connector to interface to a motor controller (male), which is provided with the DEP mechanism. The motor controller will be controlled by EPS.
A standard, serial cable with female DB-9 connector on both ends will connect the motor controller to the DEP mechanism. The motor controller to EPS system interface is yet to be determined.
PM/EPSThe photomultiplier requires 800V DC and outputs pulses at TTL levels. The PM also requires a ground connection.
A TBD 2 pin power connector (insulated) will connect the EPS board to the PM. A separate, TBD connector will transmit the pulse train to the asynchronous line at a TBD Baud rate.
RockSat-C 2012PDR
Requirement Verification
• At the PDR level, highlight the most critical project/system requirements and determine how you will VERIFY these requirements– This starts the process of test planning
• Verification: did you build the thing right?– Validation: did you build the right thing – we
won’t focus too much on validation, because it is more of a customer consideration
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RockSat-C 2012PDR
Requirement Verification Example Table
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Requirement Verification Method DescriptionThey deploable boom shall deploy to a height of no more than 12”
Demonstration Boom will be expanded to full length in the upright position to verify it doesn’t exceed 12”
The boom shall extend to the full 12” height in less than 5 seconds from a horizontal position.
Analysis The system’s dynamical characteristics will be derived from SolidWorks, and available torques will yield minimum response time.
The full system shall fit on a single RockSat-X deck
Inspection Visual inspection will verify this requirement
The sytem shall survive the vibration characteristics prescribed by the RockSat-X program.
Test The system will be subjected to these vibration loads in June during testing week.
RockSat-C 2012PDR
Why do we care about requirements?
• At this point, I will be checking to make sure you have a good set of requirements to define your project
• This comic is an entertaining, but accurate, depiction of what can happen with a project that is not well defined, managed, and documented
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http://www.codinghorror.com/blog/2005/03/on-software-engineering.html
RockSat-C 2012PDR
Subsystem DesignName of Subsystem
*You will have several subsystems*
Name of Presenter
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RockSat-C 2012PDR
Subsystem Design Section
• This section is where you explain how each subsystem was designed
• Discuss how you researched components that would meet your requirements– Show trade studies if necessary, and if you
show them, be prepared to explain the scoring and categories
• The most important part is explaining how you reached your major design decisions in each subsystem
• After explaining components, discuss any risks associated with this subsystem
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RockSat-C 2012PDR
Subsystem Overview – Block Diagram• Show your subsystems, now with more detail inside
the boxes, and the connections between them
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RockSat-C 2012PDR
EPS: Block Diagram
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• Show the subsystem block diagram with primary component choices highlighted.
Power
Data/Control
Legend
RockSat-C 2012PDR
EPS: Trade Studies
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• Show rationale for you choices in components. You basically weigh your options against your requirements and what each component can offer. Don’t forget things like: availability, cost, and prior knowledge. I recommend an online search for examples if you are unsure, or contact me.µController XMega ATMega 32 L
Cost 8 10Availability 10 10
Clock Speed 10 5A/D Converters 9 5Programming
Language8 8
Average: 9 7.6
• You should have completed a trade study for each block, but you only need to present the 2-3 most important.
• Numbers are relatively subjective, but 10 should represent a perfect fit, 5 will work, but is not desirable, and 0 does NOT meet expectations.
• The component with the highest average should drive your choice for design.
RockSat-C 2012PDR
EPS: Risk Matrix
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EPS.RSK.1: Mission objectives aren’t met IF microcontroller fails in-flightEPS.RSK.2: Mission objectives aren’t met IF a suitable motor controller cannot be procured EPS.RSK.3: The EPS system can’t survive launch conditions, and the mission objectives aren’t metEPS.RSK.4: A strain will be put on the power budget IF flying monkeys delay the launch by an hour
• Risks for the subsystem under discussion should be documented here
• The horizontal represents the likelihood of a risk, the vertical is the corresponding consequence.
• Risks placement should help drive mitigation priority
RockSat-C 2012PDR
Writing Risks – a note
• When you write a risk, you are writing about the bad thing that might result, NOT the cause– Ex: “Risk 1: There might be one+ month delay
in obtaining our science instrument” – not quite. This is the cause. The RISK is what this might do to your project, like delay testing, integration, schedule, etc, so you could write “Risk 1: The integration schedule will slip due to delays in procuring the science instrument”
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RockSat-C 2012PDR
Prototyping PlanName of Presenter
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RockSat-C 2012PDR
Prototyping Section
• The purpose of this section is to help you identify what components/connections might need testing before you can say with confidence that you want something in your final design
• Not everything must be prototyped (you don’t have time)
• Prototypes are usually used to address risks
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RockSat-C 2012PDR
Prototyping Plan
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Concern about mounting the PM to the deck has been
expressed (Risk: jeopardize the mission objectives)
STR
PM
DEP
EPS
Concerns about testing the PM on the ground have
been expressed
Mounting the probe to the end of the boom will present a
significant challenge
The functionality of the microcontoller board needs
to be verified by CDR
Prototype this interface and verify the fit with
the PM
Develop a test plan and verify it with LASP
mentors
Mount a test probe and verify structural rigidity
Prototype the micro board on a bread board
to verify functionality
Risk/Concern Action
• What will you build/test between now and CDR to mitigate risks?
RockSat-C 2012PDR
Project Management PlanName of Presenter
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RockSat-C 2012PDR
RockSat-C 2012 User’s Guide Compliance
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• Rough Order of Magnitude mass estimate– Initial masses of major components,
sensors, structural pieces– Start thinking about BALLAST
• CG – predicted CG based on your design
• Are you using high voltage– How are the schematics/safety coming
along?• Are you using any ports? How will
you interface with them? Are you sharing an atmospheric port? – you may not know some of these at this time, which is fine
RockSat-C 2012PDR
Sharing Logistics – if applicable
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• If known:• Who are you sharing with?
– Summary of your partner’s mission (1 line)
• Plan for collaboration– How do you communicate?– How will you share designs
(solidworks, any actual fit checks before next June)?
• Structural interface – will you be joining with standoffs or something else (again, be wary of clearance)?
grandpmr.com
RockSat-C 2012PDR
Organizational Chart
• Please turn your organization from CoDR into an official chart• What subsystems do you have?• Who works on each subsystem?
– Leads?• Don’t forget faculty advisor/sponsor(s)
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Project ManagerShawn Carroll
System EngineerEmily Logan
CFOShawn Carroll
Faculty AdvisorChris Koehler
SponsorLASP
Faculty AdvisoryRiley Pack
Safety EngineerChris Koehler
Testing Lead Jessica Brown
EPSDavid Ferguson
Riley Pack
STRTyler Murphy
Aaron Russert
DEPAaron RussertShawn Carroll
PMKirstyn JohnsonElliott Richerson
RockSat-C 2012PDR
Schedule
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• What are the major milestones for your project?• (i.e. when will things be prototyped?)• CDR• When will you begin procuring hardware?• Start thinking all the way to the end of the project!
• Rough integration and testing schedule in the spring• Etc, etc, etc
• Format:• Gant charts• Excel spreadsheet• Simple list• Whatever works for you! Don’t let the schedule
sneak up on you!
schedule
RockSat-C 2012PDR
WBS
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• Present a very top-level work break down schedule• One can look up the tree for large scope goals• One can look down the tree for dependencies• Help each subsystem “see” the path ahead• Based on the schedule and requirements
PMP EPS STR PM DEP
•Obtain PM from LASP
•EEF Proposal for funding•…•…
•Trade Studies
•Schematics
•Schematic Review
•ICDs
•First Revision of Boards
•…•…
•Trade Studies
•Order Materials
•Work Request Into Shop
•…•…
•Obtain PM from LASP
•EEF Proposal for funding
•…•…
•Obtain PM from LASP
•EEF Proposal for funding
•…•…
RockSat-C 2012PDR
Budget
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• Present a very top-level budget (not nut and bolt level)• A simple Excel spreadsheet will do• Most important factor is LEAD TIME
• Simply to ensure that at this preliminary stage you aren’t over budget• It is suggested that you add in at least a 25% margin at this point
Margin: 0.25 Budget: $1,300.00 Last Update: 9/30/2010 11:50ExampleSat
Item Supplier Estimated, Specific Cost Number Required Toal Cost NotesMotor Controller DigiKey $150.00 2 $300.00 1 for testingPM LASP $0.00 1 $0.00 LASP mentor deserves shirtMicrocontroller DigiKey $18.00 3 $54.00 3 board revsPrinted Circuit Boards Advanced Circuits $33.00 3 $99.00 3 board revsMisc. Electronics (R,L,C) DigiKey $80.00 3 $240.00 3 board revsBoom Material onlinemetals.com $40.00 2 $80.00 1 test articleProbe LASP $0.00 1 $0.00 Testing Materials ??? $200.00 1 $200.00 Estimated cost to test system
Total (no margin): $973.00Total (w/ margin): $1,216.25
RockSat-C 2012PDR
• Summarize your main action items to get done before CDR
• Issues, concerns, any questions
Conclusion
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