Full Mission SIMULATION AND Testing Report: WEST VIRGINIA UNIVERSITY

FULL MISSION SIMULATION AND TESTING REPORT:

WEST VIRGINIA UNIVERSITY

Justin Yorick, Ben Province, Marc Gramlich, William Kryger, Alex Bouvy Advisor:Dimitris Vassiliadis

Mission Overview The purpose of the WVU payload is to

measure several physical parameters of the atmosphere as a function of altitude.

Experiments include:GHGE- Greenhouse Gas ExperimentRPE- Radio Plasma ExperimentCRE- Cosmic Ray ExperimentCLE- Capillary Liquid ExperimentFD- Flight Dynamics

3

WVU Payload 2012: Concept of Operations

h=75 km (T=01:18) RPE Tx ON

h=75 km (T=04:27)RPE Tx OFF

h=117 km (T=02:53)Apogee

h=0 km (T=13:00)Splashdown

h=10.5 km (T=05:30)Chute deploys

h=52 km (T=00:36)End of Orion burn

H=1.52 km t=004.x s Wallops Valves Open

H=1.52 km t=771 s Wallops Valves CloseSolenoid Valves Close

h=0 km (T=00:00)Pre-Launch activation signal

GHGE processor and sensors power up

WVU Payload The updated payload is shown here:

GHGE

CRE

FD

RPE

Not shown: CLE

Subsystem Overviews

Subsystem Overview Greenhouse Gas Experiment(GHGE): The

GHGE is designed to measure the concentration of Carbon Dioxide, water vapor and ozone gas concentrations as function of altitude in the atmosphere. The system uses a dynamic port for air input and a static port for exhaust.Currently the mechanical components of the

GHGE are assembled and operational with temporary “patch brackets” and an interim control volume highlighted on the next slide.

Greenhouse Gas Experiment “Patch

Brackets”

Interim CV

Original Brackets

Plumbing and Solenoid Valves

Subsystem Overview Flight Dynamics (FD):The FD

subsystem is responsible for measuring the kinematics of the payload in flight. From this information, the data from all other subsystems can be correlated to altitude of the payload.

Flight Dynamics

Revised FD Circuit Board (3D Rendering)

Revised FD Circuit Board(Trace Schematic)

Subsystem Overview Radio Plasma Experiment (RPE): The

RPE will measure the density of ambient plasma in the ionosphere. A ferrite rod will act as a transmitting and

receiving antenna for the 1.3-6.3 MHz signalsA patch antenna at a special port of the rocket

will be used to transmit the 5.826 GHz signal A Langmuir probe will be used as a

secondary sensor.

Subsystem Overview Cosmic Ray Experiment (CRE): The

CRE will use an array of Geiger tubes to record the flux of high energy particles.

These tubes have varying thickness of shielding to identify various energies of particles based on penetrating power.

Subsystem Overview Capillary Liquid Experiment (CLE):

The CLE records the dynamic capillary actions of a liquid in the microgravity conditions experienced in portions of the flight. This behavior will be monitored by recording the position of the fluid against a gridded background. Parts for this experiment are ready to fly from last year.

Full Scale Testing The full scale testing is initiated by using

the activation signal. With this activation, the entire payload

control scheme begins operation. The remainder of the report details the

testing sequences performed on each subsystem.

Testing Protocols

GHGE Testing Protocols Flow Test Simulation of flow in manifold structure has

proven difficult and inconclusive. Flow rates under different solenoid

configurations is a requirement for effective GHGE control scheme.

Using a flowmeter, the GHGE manifold flow rates will be measured after exposing the dynamic input to pressurized air, and the static exhaust to atmosphere.

GHGE Testing Protocols Internal Volume Test To optimize the control scheme

parameters, a precise internal volume of the manifolds and testing volume must be known.

Using the system temperature and pressure sensors, the internal volume will be calculated by inducing a known change in volume via the piston and observing the pressure change.

GHGE Testing Protocols Gas Concentration Tests By using concentrated carbon dioxide

gas and water vapor, the team can test the steady state and transient responses of the gas concentration sensor.

These gases are added to the flow at the dynamic input port.

GHGE Testing Protocols Linear Actuator Transient Response The linear actuator is used to compress air

under different dynamic conditions. It is of interest to know how long the

actuator takes to achieve full piston compression under different pressure loads.

The power required to compress the gas will be recorded and used to update the power budget.

RPE Testing Protocols Waveform Generation Test The RPE relies on the generation of a

variable frequency pulse sweep. To ensure the proper waveforms are

produced, the output signal will be measured by an oscilloscope.

The oscilloscope used in the lab is capable of displaying and capturing waveforms as well as performing frequency analysis.

RPE Testing Protocols Patch Antenna The patch antenna will be tuned and

impedance matched to the 5.826 GHz transmitter using a network analyzer

RPE Testing Protocols Data Writing Test The RPE writes data in ASCII format to a flash

memory SD card. This data is imported into Matlab and the data packets are converted to useable measurements.

Matlab informs the user of corrupted data packages in this process.

Such analysis allows the team to verify the data writing process is working properly.

This data writing process is the same for the remaining subsystems as well.

FD Testing Protocols Kinematic Perturbation Test One of the main goals of the FD

subsystem is to measure kinematic variables in the rocket flight.

By activating this subsystem and exposing it to small fast controlled perturbations by hand, the sensor response can be recorded and tested for proper response.

FD Testing Protocols Magnetometer Test By exposing the magnetometer to a

magnetic field generated by a local permanent magnet, the sensor response can be calibrated.

CRE Testing Protocols Geiger Rate Count Test The Geiger arrays are used to measure

pulse activation caused by particle collisions within a time interval.

Using a known radioactive source the count rates of the CRE can be measured.

This test also inherently tests the data recording and software formatting for the CRE.

Testing Results

GHGE: Subsystem Assembly and Testing (top view)

GHGE: Subsystem Assembly and Testing (side views)

GHGE: Control Volume Testing

GHGE: Flow Test This test is not yet complete. We have

secured a compressor, vacuum pump, regulators, and a flowmeter, but require additional fittings to connect the components.

The flow test for the GHGE with the interim control volume is expected to be completed the week of April 23rd.

GHGE: Internal Volume Test This test is not yet complete. The

Internal Volume Test requires pressure sensors to be present in the control volume as well as the high-pressure manifold.

This test is expected to be completed the week of May 7th.

GHGE: Sensor Control and Data Acquisition Test

GHGE: Gas Concentration

GHGE: Gas Concentration

GHGE: Modeled Time Constants (rise) CO2 Tank Manifold Pressure (psi)

Test Type (cold/hot) Time Constant

38 Cold 7.80

50 Cold 13.25

60 Cold 21.60

40 Hot 3.7

• At this point, more testing is needed for the hot test configuration.• CO2 pressures need to be related to expected flow regimes in

payload flight.

GHGE: Linear Actuator ResponsePressure

DifferenceFull-Stroke

Actuation Time Voltage Current Power Energy (approx)

PSIG s v A W mW-hr

0 1.31 12 0.4 4.8 1.7

5 1.35 12 0.7 8.4 3.2

10 1.44 12 1.0 12.0 4.8

15 1.56 12 1.3 15.6 6.8

20 1.71 12 1.5 18.0 8.6

25 1.82 12 1.6 19.2 9.7

30 1.90 12 2.1 25.2 13.3

35 1.97 12 2.6 31.2 17.1

GHGE: Linear Actuator Response

0 5 10 15 20 25 30 35 400.00

0.50

1.00

1.50

2.00

2.50

f(x) = 0.0206190476190476 x + 1.27166666666667R² = 0.985979858536457

Actuation Time

Actuation Time

Linear (Actuation Time)

Pressure Difference (PSI)

Actu

atio

n Ti

me

(s)

Actuation time for each pressure difference was measured with a stopwatch

GHGE: Linear Actuator Response

0 10 20 30 400.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

f(x) = 0.697142857142857 x + 4.6R² = 0.973574045002616

Power

Power

Linear (Power)

Pressure Difference (PSI)

Pow

er (W

)

Motor power consumption calculated as the product of steady-state current and potential.

GHGE: Linear Actuator Response

0 5 10 15 20 25 30 35 400.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

f(x) = 0.00669523809523803 x² + 0.18125396825397 x + 2.03472222222221R² = 0.990249135483274

Energy (approximate)

Energy (approx)

Polynomial (Energy (approx))

Pressure Difference (PSI)

Ener

gy (m

W-h

r)

Approximate energy was calculated by multiplying power by time.

This does not include energy estimation does not include losses encountered in the mechanical components.

GHGE: Linear Actuator Response Test Setup

Current Potential

Compressed air at dynamic port

Static port exhausted to atmosphere

GHGE: Linear Actuator Response Other Useful information:

The drivetrain will self-start when the motor is unpowered if the pressure difference in the piston-cylinder is greater than 12 PSI.

The solenoid valves require at least 10v to open, but will remain in the open position when voltage is stepped down to 3v. Due to their fixed resistance and Ohm’s law, current draw is also significantly reduced by lowering the voltage.

GHGE: Linear Actuator Response While under pressure, the piston tends to turn in

the cylinder. This will cause problems with the rotary optical

encoder based position sensing strategy. We are currently exploring options including:

Replacing the rotary optical encoder with a linear potentiometer

De-emphasizing the encoder data in the control scheme by allowing the piston to hit end-stops and making decisions based on pressure instead of position.

Adding a keyway to the ballscrew.

RPE: Waveform Test The following figures show sample

waveforms obtained from the RPE waveform generator.

RPE: Wave Output

RPE: Antenna Testing The antenna has been tested for

frequency response. Due to nature of testing apparatus, a graphic of these responses is not available at this time. It has been found that the antenna has a loss of 21dB at 5.826GHz.

FD: Sensor Tests

IMU sensor

Gyro

NetBurnersocket

FD: Gyro Test

Z-Axis Gyro Test

FD: Magnetometer Test

FD: Magnetometer Test (cont.)

FD:IMU Testing

FD: IMU Testing (cont.)

CRE: Geiger Counter Assembly

CRE: Geiger Rate Test The following graphs summarize the results of the Geiger

test for a single tube. It can clearly be seen that the CRE electronics are

operational.

Work Breakdown Schedule

Conclusions From This Test Stage The FD, CRE, and CLE subsystems are

nearing completion The RPE subsystem has all components

built and ready to be integrated. The system is currently in the tuning and optimization stage.

The GHGE subsystem sensor components and actuators have been tested. Full integration of the system is underway.