Development of a Payload Derived Position Acquisition System for Parachute Recovery Systems

Tiaden, Ryan D.; Yakimenko, Oleg A.

doi:10.2514/6.2008-7487

Cited by 4 publications

(1 citation statement)

References 2 publications

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“…An IMU is particularly useful in airborne parachute testing where the GPS solution is typically lost for about 30 seconds after the test vehicle is extracted from the parent aircraft. (8) This happens as the GPS transitions from receiving a re-radiated signal inside the cabin to direct satellite observations. IMU errors will accumulate with time due to bias and drift.…”

Section: Global Positioning System (Gps)mentioning

confidence: 99%

Measurement of CPAS Main Parachute Rate of Descent

Ray

2011

21st AIAA Aerodynamic Decelerator Systems Technology Conference and Seminar

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The Crew Exploration Vehicle Parachute Assembly System (CPAS) is being designed to land the Orion Crew Module (CM) at a safe rate of descent at splashdown. Flight test performance must be measured to a high degree of accuracy to ensure this requirement is met with the most efficient design possible. Although the design includes three CPAS Main parachutes, the requirement is that the system must not exceed 33 ft/s under two Main parachutes, should one of the Main parachutes fail. Therefore, several tests were conducted with clusters of two Mains. All of the steady-state rate of descent data are normalized to standard sea level conditions and checked against the limit. As the Orion design gains weight, the system is approaching this limit to within measurement precision. Parachute "breathing," cluster interactions, and atmospheric anomalies can cause the rate of descent to vary widely and lead to challenges in characterizing parachute terminal performance. An early test had contradictory rate of descent results from optical trajectory and Differential Global Positioning Systems (DGPS). A thorough analysis of the data sources and error propagation was conducted to determine the uncertainty in the trajectory. It was discovered that the Time Space Position Information (TSPI) from the optical tracking provided accurate position data. However, the velocity from TPSI must be computed via numerical differentiation, which is prone to large error. DGPS obtains position through pseudo-range calculations from multiple satellites and velocity through Doppler shift of the carrier frequency. Because the velocity from DGPS is a direct measurement, it is more accurate than TSPI velocity. To remedy the situation, a commercial off-the-shelf product that combines GPS and an Inertial Measurement Unit (IMU) was purchased to significantly improve rate of descent measurements. This had the added benefit of solving GPS dropouts during aircraft extraction. Statistical probability distributions for CPAS Main parachute rate of descent and drag coefficient were computed and plotted. Using test data, a terminal rate of descent at splashdown can be estimated as a function of canopy loading.

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Section: Global Positioning System (Gps)mentioning

confidence: 99%

Measurement of CPAS Main Parachute Rate of Descent

Ray

2011

21st AIAA Aerodynamic Decelerator Systems Technology Conference and Seminar

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References

2015

Precision Aerial Delivery Systems: Modeling, Dynamics, and Control

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Concept Refinement of the Payload Derived Position Acquisition System for Parachute Recovery Systems

Tiaden¹,

Yakimenko²

2009

20th AIAA Aerodynamic Decelerator Systems Technology Conference and Seminar

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The paper covers the continued development of a Payload Derived Position Acquisition System (PDPAS) to overcome current limitations posed on recovering the trajectory data for a generic parachute recovery system (PRS). The PDPAS is an instrumentation set and software algorithm that is to be installed onto PRS in order to estimate PRS state vector parameters in real-time for testing and operational use. The development of the PDPAD has progressed to a point where it is providing quality data and is ready for development into a usable instrumentation package. The paper discusses the concept of the PDPAS, the first implementation of the PDPAS, changes made to the PDPAS due to continued development, and the steps for needed for the PDPAS to be a validated instrumentation package.

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Development of a Payload Derived Position Acquisition System for Parachute Recovery Systems

Cited by 4 publications

References 2 publications

Measurement of CPAS Main Parachute Rate of Descent

Measurement of CPAS Main Parachute Rate of Descent

References

Concept Refinement of the Payload Derived Position Acquisition System for Parachute Recovery Systems

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