Mont Alto Projectile Project (M.A.P.P.) Critical Design Review

1
Mont Alto Projectile Project (M.A.P.P.)
Critical Design Review

• Penn State Mont Alto
• 12/17/08

2
Team Members

• Kylie Flickinger Mechanical Engineering
• Adam Kuhlman Data Acquisition
• William K. McDannell Jr. Software
• Chris Small Strain Gauge Board
• Robert Stottlemyer Team Leader
• Tim Svirbly Test Equipment Development

3
Abstract

• The purpose of this experiment is to investigate
  the mechanical stresses in an elastic structure
  during the flight of a sounding rocket. The
  structure proposed consists of a circular plate,
  the deck plate, which is supported by four
  longerons, which connect in turn to circular
  plates at either end of the longerons simulating
  a payload section of previous sounding rocket
  flights. A dummy mass is attached to the center
  of the deck plate. During the flight, dynamic
  loads in the axial and lateral directions will
  cause the deck plate to deflect. The resulting
  deformation will be measured at selected points
  using strain gauges connected to electronic
  boards to obtain time-varying voltage signals
  which in turn will be digitized and stored for
  later analysis. The obtained data will be
  compared to theoretical predictions. Careful
  pre-flight calibration of the entire data stream
  will be conducted.

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• Subsystem Requirements

• Mechanical Subsystems
• Bottom Plate
• Deck Plate
• Top Plate
• Longerons
• Test Weight
• Trays for Boards
• Braces

• Electrical Subsystems
• G-Switch Latched Relay
• Battery and Regulation
• Strain Gauge Boards
• Strain Gauges
• Controller A/D conversion
• Data Storage

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• Schematic/Drawings/Analysis
• See next slides

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Brace A
7
Brace B
8
Brace C
9
Bottom Disk
10
Deck plate
11
Top disk
12
Longeron
13
Tray A
14
Housing , Battery G-switch
15
Test weight
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Assembly Mont Alto
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BU Magnetometers
Block Diagrams
PSU MA Strain Gauges
Strain Gauge
Controller
A/D
Data Card
Power
Launch safing
G-switch
Controller
A/D
Data Card
Power
G-switch
Launch safing
18
Strain Gauge Circuit
19
Strain Gauge (Up Close)
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Strain Gauges

• After testing in SolidWorks, we determined that
  the deck plate would not deform enough for the
  strain boards that we built for the USERS program
  to amplify the signal enough to get meaningful
  data using metal strain gauges. After research,
  we decided to use semi-conductor strain gauges,
  which have a gauge factor of 60 times that of a
  metal foil strain gauge. We will implement them
  in a configuration that would both double signal
  output and reduce concerns about temperature
  sensitivity. Using this configuration should
  allow us to use our boards from the USERS program
  with only minor changes.

21
G-Switch Latched Relay
22
Controller Memory

• Memory Needs 12 Analog Signal Streams each
  digitized at 250 samples/second to be sampled
  for 750 seconds at 2 bytes per sample 4.5
  Megabytes
• Data stored on a SD card inserted into Miniboard
  (45mm x 55 mm) - www.futurlec.com/mini_sc.shtml
• standard SD or SPI communication. 3 Volt
  power
• Microcontroller Board www.microchip.com/wwwprod
  ucts/devices.aspx?ddocnameen024691 Model
  PIC24HJ256GP206 , 18 channels 12 bit A/D
  conversion at up to 500 ksps,
  2-UART,2-SPI, 2-12C digital communication, 3 to
  3.6 Volt power with on-chip 2.5 Volt power
  regulator, size 1.0x2.2 . Programming
  language C

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• Special Requirements
• Shift in center of mass along length axis on
  rocket

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• Commands and Sensors
• Always On Triggered by the G-Switch
• Turned off by microcontroller before splash down
• 12 Analog Signal Streams each digitized at 250
  samples/second to be sampled for 750 seconds at 2
  bytes per sample 4.5 Megabytes
• Data stored on a SD card Miniboard (45mm x 55 mm)
  - www.futurlec.com/mini_sc.shtml
• Microcontroller Board (protopic 28) 1.0 x 2.2
  www.microchip.com/wwwproducts/devices.aspx?ddocn
  ameen024691 Model PIC24HJ256GP206 , 18
  channels A/D conversion, on-chip 2.5 Volt power
  regulator
• Strain Gauge Vishay or Semiconductor (to be
  decided)
• Data Acquisition Controlled by Microcontroller
  initiated by power on

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• Test Plans
• Mechanical Stress Distribution
• SolidWorks
• Thin Plate Theory
• Static Force Rig (similar to the one we used for
  USERS)
• G-Switch and Latched Relay
• Spring loaded launch in a controlled setting
• Ensure compliance with no-volts requirement when
  integrated with power supply
• Strain Gauges
• Temperature sensitivity
• Circuitry and Signal Strength simple beam test
• Compare to metal foil strain gauges
• Calibration
• Data Acquisition/Storage
• Store and retrieve data
• All electronics Burn in period

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Timeline

• By the end of fall semester (12/19/08)
• Critical design review completed
• Begin ordering parts
• Wrap up design phase
• Over Christmas Break (12/19/08 01/12/09)
• Continue ordering parts
• Begin planning build phase
• Beginning of Spring Semester (01/12/09)
• Meet to plan build phase
• Take an inventory of parts
• Between (01/12/09 03/15/09)
• Build Phase
• Manufacture circuit board for data collection
• Alter strain gauge boards
• Manufacture testing rigsStatic force rig like we
  used for USERS, Spring mechanism to test G-Switch
• Manufacture G-switch
• Manufacture plates, longerons, alter dummy weight
  from USERS, braces, and housing for battery and
  g-switch.
• Between (3/15/09 4/25/09)
• Testing Phase

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• Parts List
• Mechanical parts
• Item Status
  Item Status
• 4 Brace A designed
  1 Test Weight Completed
• 4 Brace B designed
  4 Trays Completed
• 8 Brace C designed
• 1 Bottom Disk designed
• 1 Deck Plate designed
• 1 Top Disk designed
• 4 Longeron designed
• Not at the nut and bolt level just major
  hardware that will be purchased or built in house
• Lead times (This can make or break a project)
• Distributors
• Manufacturers
• Cost (Dont forget to consider shipping and tax)

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Parts list, cont.

• Electronic Parts
• Item Status
• 2 Strain gage board Modification
  needed
• 1 Power regulator board Modification
  needed
• 1 G-switch and associated electronics -
  needs more design work
• 1 data acquisition/storage controller -
  needs more design work

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• RockSat Payload Canister User Guide Compliance
• Mass, Volume
• Estimates of mass include everything shown in
  slide 16 . Missing are the electronic boards ( 4
  of 4x4 ) for MA and electronic board and
  tray/box for BU
• m 10.86 lbs (lt 12.75, the heavy test
  mass can be reduced)
• Center of mass 0.35 off axis and 1.06
  below geometric center. Because electronic
  boards and tray for the BU experiment have not
  been included, the center of mass will move
  slightly closer to the geometric center.
• Entire structure fits into a cylinder of 9
  (lt9.2) diameter and
• 9.275 (lt9.4) height leaving 0.125 for
  washers.
• Connection with 5 bolts to top and bottom
  bulk head , respectively, is provided.

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RockSat Compliance - continued

• Payload Activation
• a battery , a G-switch, and shorting wires
  to Wallops shorting plug form a complete loop
  with electric current flowing only if both the
  G-switch and shorting plug are in closed position
  simultaneously. Once current is flowing a circuit
  consisting of a second battery (ies) and all
  electronic boards is activated using a
  solid-state latched relay and switch transistor.
  This second loop maintains itself even when the
  G-switch subsequently falls back into its open
  position (during ballistic flight phase). See
  slide 29

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• Shared Can Logistics Plan
• Boston University (Mike Ruane)
• Penn State Mont Alto (Zig Herzog)
• Sharing mechanical structure but independent
  power supply, controller, data acquisition, and
  data storage. Possibility of future sharing of
  these items is not excluded .

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Management

• Dr. Siegfried Herzog
• Penn State University at Mont Alto
• Assistant Professor of Mechanical Engineering
• 1 Campus Drive
• Mont Alto, PA 17237
• Tel [phone]    Fax [phone]
• E-Mail hgn_at_psu.edu
• Dr. Michael Ruane
• Professor, ECE Dept.,
• Boston University
• 8 St. Mary's Street, Boston, MA 02215
• Phone [phone] fax
• E-Mail mfr_at_bu.edu

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• Conclusions
• Lab space available
• Students are nervous but excited
• We have some previous experience with the USERS
  program and can re-use some parts
• We aim to finish by the end of April (end of the
  spring semester)
• Looking forward to beach time! ?