Automated Data Acquisition for an Infrared Spectrometer Lauren Foster 1, Obadiah Kegege 2, and Alan...
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Transcript of Automated Data Acquisition for an Infrared Spectrometer Lauren Foster 1, Obadiah Kegege 2, and Alan...
Automated Data Acquisition for an Infrared SpectrometerLauren Foster 1, Obadiah Kegege 2, and Alan Mantooth 2,3
1 Manhattan College, Bronx, NY,2 Arkansas Center for Space and Planetary Sciences, University of Arkansas, Fayetteville, AR.
3 Department of Electrical Engineering, University of Arkansas, Fayetteville, AR.
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Inside Sensor
DC input +
DC input -
Sensor out +
Sensor out -
PLC Terminal
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RI
RI
RI sensor
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Calibration• Software calibration done such that the sensor is balanced at a
given reference value
• Output scaling done from the HMI tag formulas
Automated Integrated System
Inputs: • Force (sensor) (analog input or AI)
• Depth (sensor) (AI)
• Up (sensor) (digital input or DI)
• Down (sensor) (DI)
• Data Acquisition Confirmation (DI)
Outputs: • Insertion and removal of probe (AO)• Motor direction (digital output or DO)• Trigger Data Acquisition (DO)• Brake the Motor (DO)• Sensor Excitation (analog output or AO)
Spectrometer on Rover
Spectrometer on Rover
GEPLC
Position/Force/SpeedTransducers
Desired position/ Force/speed
Position
Force
Motor
Feedback loops
Speed
Schedule Data Acq.
Control of Speed and Force of the Probe
For feedback controls:
HMI (Human to Machine Interface)
•Automated System controlling:
- insertion, withdrawal, and data acquisition
fiber optics to IR module
window overthe fiber optic illuminate and sense elements
PLC
Analog Sensor Interface• Analog sensors:
- Force, Depth, Speed
• Example:
- Wheatstone bridge is very common for design
• The circuit is balanced if Ssensor _ Vout = 0
• Where Rsensor is the resistance of an analog sensor at reference voltage
Objectives• Design, assemble and program all electrical and
mechanical parts of the automated control system
• Produce an OPRA prototype to acquire IR (infrared) data for spectrometer on a robotic arm or rover
Background of Research• OPRA
- “Optical Probe for Regolith Analysis”
• A NASA funded project currently under development by the University of Arkansas
• Current data:
- Obtained manually
- Insertion & withdrawal of a probe
in regolith (loose soil and rock)
- Data acquisition
• Future data:
- Obtained from an automated control system
- Acquire, store and analyze data
- From infrared spectrometer on a robotic arm or rover
Operating Procedure• The operator specifies operating mode:
- (1) Constant Velocity
- (2) Constant Force
• Press “start data acquisition”
• System will create relationship between:
- Regolith Strength vs. Depth
• Obtain IR data:– (1) Constant Velocity Mode:
- Probe is inserted at constant speed
to a designated depth
- Penetration Force vs. Depth recorded
- IR data taken
– (2) Constant Force Mode:
- Probe is inserted at constant force
- Probe inserted until balanced by the resistance
strength from the regolith.
- Penetration Depth vs. Time recorded
- IR data takenData Storage and Plotting
• Computer:- Force and depth data stored
- Data plotted for analysis
• IR data stored by onboard spectrometer
Conclusions• The automated system will be very helpful for
IR data acquisition, plotting, and analysis
• It will also help to characterize strength of regolith at each depth
Acknowledgements• I would like to offer my thanks to all individuals who
advised me, especially my fellow participants in the OPRA project. It is an honor to be part of a project that may one day find its way to the Moon or Mars.
References1. Ulrich et al. (2006). “Fiber Optic Spectral Array on a
Regolith Probe for Surface and Sub-Surface Mineralogical Profiling: Optical Probe for Regolith Analysis”, Arkansas Center for Space & Planetary Sciences, University of Arkansas
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