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Electronic Parachute Deployment System
Pre-proposal
Team 7: Kyle Christian, Moses Jones, Ryan Lupinski,
Ian McCall, and Tayloire Thomas
Sponsor: Texas Instruments
Faculty Facilitator: Jes Asmussen
9/20/2013
Executive Summary
The purpose of this project is to design, simulate, fabricate, test, and demonstrate a TI-based electronic parachute deployment system for large model rockets.
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Table of Contents
Executive Summary.....................................................................................................................................1
Introduction.................................................................................................................................................3
BACKGROUND.............................................................................................................................................3
Mission Statement...................................................................................................................................4
Objectives................................................................................................................................................4
Problem Specifications............................................................................................................................4
Gant Chart...................................................................................................................................................5
Conceptual Design.......................................................................................................................................7
RISK ANALYSIS...........................................................................................................................................11
Budget.......................................................................................................................................................11
References.................................................................................................................................................12
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Introduction
Everything that goes up must come down, and it must do so safely. This is certainly true when it comes to model rockets. This proposal outlines a potential solution to that problem. Included in the design for the Electronic Parachute Deployment System (EPDS) will be an accelerometer and altimeter to detect acceleration/velocity and altitude, which will trigger two separate parachute releases. Also, an LCD display will report real-time data, such as altitude reached and acceleration.
BACKGROUND
Within this section of the pre-proposal, the topics covered during preliminary research will be discussed- namely an overview of this project’s main components, including respective roles within design and simulation.
Accelerometer:o Measures acceleration acting on aircraft via normal (perpendicular) G-forces.
When rocket reaches apex of flight and begins free-fall (a= 0 m/s^2) the accelerometer will trigger the microcontroller to deploy the streamer (initial parachute).
(Barometric) Altimeter:o Measures the altitude of the aircraft via atmospheric pressure. This component
is the other half of the solution to the initial problem of slowing the descent of the aircraft. Once the descent reaches a pre-programmed height, the altimeter will trigger microcontroller to deploy the larger parachute.
Booster Pack:o Printed circuit board (PCB) housing the accelerometer and altimeter which will
communicate with the microcontroller. LCD:
o Will display the flight’s peaks in altitude and acceleration. MSP430 LaunchPad:
o Microcontroller used to program and communicate with respective sensors.
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Mission Statement:
To produce a cost effective and lightweight working PCB component to interface with a TI MSP430 micro controller that would electronically deploy parachutes in two phases to safely bring a model rocket back to the ground.
Objectives:
1. Build relationship with Texas Instruments and clearly define concept of project2. Produce conceptual solution and initial design for PCB circuit3. Establish budget criteria, order parts, and create proto-type4. Test proto-type and implement changes5. Optimize weight of component and integrate to MSP430 micro controller6. Full integration into model rocket and final testing
Problem Specifications:
Must develop a “Booster Pack” that is compatible with a T.I. MSP430 MC Booster Pack must utilize accelerometer, altimeter, and LCD with real time data Booster Pack must be integrated to the MSP430 MC to deploy parachutes in two
phases. o 1: Initial stability parachute at peak of launch.o 2: Secondary parachute at defined altitude for final descent
Project must meet $500 budget + T.I. stipend and be deliverable by Design Day
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Gant Chart
Task Mode Task Name Duration Start Finish Predecessors Resource
NamesManually Scheduled
Electronic Deployable Parachute Project 58 days Wed
9/4/13Fri 11/22/13
Manually Scheduled
Project Definition Phase 15 days Mon
9/9/13Fri 9/27/13
Manually Scheduled
Initial Group Meeting 1 day Tue
9/10/13Tue 9/10/13
Manually Scheduled
First Sponsor/Facilitator Meeting
1 day Thu 9/12/13
Thu 9/12/13 3
Manually Scheduled Research / Proposal 11 days Thu
9/12/13Thu 9/26/13
Manually Scheduled
Group Meeting (Develop: Block Diagram & Pre-Proposal)
1.5 days Tue 9/17/13
Wed 9/18/13
Manually Scheduled
Block Diagram for TI Due 0 days Thu
9/19/13Thu 9/19/13 6
Manually Scheduled Pre Proposal Due 0 days Fri 9/20/13 Fri 9/20/13 7
Manually Scheduled
Revise Pre-Proposal, Develop Final Proposal 16 days Fri
9/20/13Fri 10/11/13
Manually Scheduled
Final Proposal Due (Asmussen, TI & Grotjohn/Udpa)
0 days Fri 10/11/13
Fri 10/11/13
Manually Scheduled
Team Oral Proposal Presentation 0 days Fri
10/11/13Fri 10/11/13
Manually Scheduled
Create Budget /Determine Parts List 2 days Fri 9/20/13 Mon
9/23/13Manually Scheduled Order Parts 2 days Mon
9/23/13Tue 9/24/13
Manually Scheduled
Contact Local Rocket Club
Mon 9/16/13
Manually ScheduledManually Phase 1: Develop 21 days Thu Thu
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Scheduled Booster Pack for MSP430 LaunchPad 9/19/13 10/17/13
Manually Scheduled
Phase 2: Integrate Booster Pack & MSP430
26 days Fri 10/18/13
Fri 11/22/13
Manually Scheduled
Size/Weight Reductions (if possible!) 8 days Fri
10/18/13Tue 10/29/13
Manually Scheduled Final Integration 16 days Wed
10/30/13Wed 11/20/13 19
Manually Scheduled
Testing and Simulation 2 days Thu
11/21/13Fri 11/22/13 20
Manually Scheduled
Team Design Issues Paper 18 days Wed
10/30/13Fri 11/22/13
Manually Scheduled
Team Design Issues Paper Due 0 days Fri
11/22/13Fri 11/22/13
Manually Scheduled
Team Technical Lecture Presentation (In Class)
0 days Fri 11/8/13 Fri 11/8/13
Manually Scheduled
Individual Application Notes Due (Asmussen)
0 days Thu 11/7/13
Thu 11/7/13
Manually Scheduled End Game 11 days Fri
11/22/13Fri 12/6/13
Manually Scheduled
Demonstrate Project Prototype (In Class) 3 days Mon
11/25/13Wed 11/27/13 21
Manually Scheduled Final Reports Due 0 days Wed
12/4/13Wed 12/4/13
Manually Scheduled Design Day 0 days Fri 12/6/13 Fri 12/6/13
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Conceptual Design
For this project we had to base our design on practicality. We want our finished product to actually be used real large scale model rockets. With that in mind we started with what we knew. The heart of our project is the MSP430 control chip (Figure 1). It will be directing the functions of our designed PCB board. Our PCB board base will be designed using a booster pack, which will consist of an Accelerometer, Altimeter, and other circuit components. These components in turn will be controlling the actions of the rockets parachutes.
(Figure 1)
For large scale model rockets, there are many designs that engineers have come up with over the last few hundred years. After researching many designs we decided on a dual parachute design that we will implement our circuit in. Before you can grasp how our circuit will work in the rocket however you must first understand the design of the rocket itself. Large model rocket bodies are made up of six separate parts. Starting from the top of the rocket and moving down in sections, first there is the “Cone” or top of the rocket. The only function of the cone is for aerodynamic purposes of flight path. Second (optional) is the “Payload” bay which is an empty bay where you can place any random items of choice. Third there is the “Drogue Parachute” bay. This bay holds the drogue parachute and its charge. The drogue parachute is considered the primary parachute which will be the first to deploy. Fourth there is the “E-bay” or electronics bay. This is where our PCB board will be placed. Fifth there is the “Main Parachute” body. Like the drogue bay the main parachute bay holds the main parachute and its charge. Lastly there is the base of the rocket. The base holds the rocket motor, and has the directional “Fins” attached. This is all shown in Figure 2.
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(Figure 2)
Now that you are familiar with the rockets design you will be able to better understand the role our circuit will play in the parachute deployment system. We designed a rough block diagram of our circuit system that is shown below in figure 3.
(Figure 3)
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As displayed in the diagram, the PCB (Booster pack) will be connected to a power supply of some sort and the altimeter and accelerometer will integrated into the board. They will be measuring the altitude and acceleration of the rocket in flight. This information will then be relayed to the MSP430 and recorded. The altimeter and accelerometer will both serve secondary proposes aside from recoding flight data. The accelerometer will not be measuring the rate of change of velocity. It actually measures acceleration associated with weight experienced by any test mass at rest. So for example if the accelerometer is at rest on the surface of the earth it will read g= 9.81 (m/ s²), while in free fall it reads g= 0 (m/s²). So for its second purpose when the rocket reaches apogee (highest point) then starts to go into free fall (g= 0 (m/s²)) it will send a current to the primary charge which will deploy the Drogue parachute as shown in Figure 4 below.
(Figure 4)
This drogue parachute is meant to let the rocket fall fast initially so it doesn’t travel far from the launch site. Once the rocket falls to a certain altitude, say 100-300ft or so, the altimeter will come into play. When the altimeter measures the set altitude we program into the MSP430 it will then send a current to the secondary charge to ignite it and deploy the main parachute. This is its secondary purpose aside from measurements. This can be seen in Figure 5 below.
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(Figure 5)
The main parachutes purpose is to slow the decent of the rocket to a safe speed so that it doesn’t take damage upon landing.
To conclude, we are very confident in our conceptual design. This design has a strong structure and of course will have to be tweaked along the way in the coming weeks. However with the research we have done we shouldn’t have any problems coming up with a PCB that will support our concept.
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RISK ANALYSIS
After conducting preliminary analysis as well as research, several possible challenges and concerns arose. These concerns stem from the need for dual parachute deployment; the parabolic nature of flight; and last but not least, the need for insulation of the rocket chamber.
Preliminary research on rocket design immediately showed that model rockets (and really anything that employs a parachute for descent) require a dual parachute system. The first parachute to be deployed is known as the drogue, and is essential because it has a smaller area than the conventional parachute. This is important, as when it is first deployed the rocket will be falling at terminal velocity and will need to be slowed down before the conventional parachute can be deployed. The alternative would result in the conventional parachute being torn apart from the high speeds and drag.
The accelerometer is the sensor that will trigger the deployment of the drogue parachute, this
will happen when the rocket reaches free-fall (a= 0 ms2
) at the peak of the flight parabola. One
potential problem is that zero acceleration occurs at two points in the flight not only the peak, but also directly before liftoff. The problem is faced again with the altimeter, which will trigger the conventional parachute at a pre-determined altitude… This will occur on the ascent as well as our targeted descent. These potential setbacks will most likely call for a delay system to be implemented.
Lastly, the chamber of the rocket will experience extreme temperature and pressure. This could wreak havoc on the experiment in that, both parachutes and the electronics bay located within the chamber could melt. This would cause the rocket to become uncontrollable free falling fuselage… essentially, a missile on the descent. The remedy to this concern will be recovery wadding, an insulation material that will bear the brunt of the pressure and temperature on the ascent, sparing the essential components and parachutes.
BudgetTBD
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References
http://ohm.nuigalway.ie/0809/csmyth/Accelerometer.html
http://www.instructables.com/id/Radio-Telemetry-for-a-Model-Rocket/
http://www.apogeerockets.com/Electronics_Payloads/Altimeters
http://www.flyrockets.com/work.asp
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