Dynamic Separation Thresholds for a Small Airborne Sense and Avoid System

Mullins, Michael; Holman, Michael W.; Foerster, Kyle; Kaabouch, Naima; Semke, William H.

doi:10.2514/6.2013-5148

Cited by 22 publications

(12 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The missing alarm rate can be computed as: (17) where n collision is the number of collisions; n not_SCA collision is the number of collisions without SCAs (the time difference between conflict and collision is smaller than k).…”

Section: B Calculation Of Missing Alarm Rate and False Alarm Ratementioning

confidence: 99%

“…Based on the above findings, the SARP conducted an integrated analysis to compare the WCs defined by the MIT, the NASA and the USAF, and came up with a quantified definition of the WC for large UAS to RTCA SC-228 [13]. Moreover, Mullins et al designed the dynamic separation threshold for the sense and avoid (SAA) system of the UAS in 2013, replaced the distance-based threshold with time-based threshold, considering the performance of intruding aircraft, and developed a solution with small computing cost using turning geometry [17]. In 2017, Duffield and McLain studied the WC definition for the airspace with dense UAS based on Automatic Dependent Surveillance-Broadcast (ADS-B) [18].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Adaptive Separation Thresholds for Self-Separation of Unmanned Aircraft System in Dynamic Airspace

Zhang

2019

IEEE Access

View full text Add to dashboard Cite

The key challenge to integrate the unmanned aircraft system (UAS) into airspace is to develop a means to sense and avoid (SAA) other aircrafts. The main function of the SAA is self-separation, i.e. remaining ''well clear'' of the other aircrafts. The separation thresholds must be quantitatively defined for the UAS to autonomously maintain self-separation. In this paper, the separation thresholds are defined quantitatively for the UAS in a dynamic airspace full of aircrafts that differ in motion state and performance. Then, a ''sector-like'' dynamic collision-free region (CFR) was set up around the UAS. The size of the CRF can be adjusted adaptively according to the relative motion states of the surrounding intruders, the performance of the UAS, and the altitude of the airspace. The simulation results show that the proposed adaptive separation thresholds adapted to the dynamic airspace environment better than the fixed separation thresholds recommended by Sense & Avoid Science and Research Panel (SARP), and controlled the missing and false alarm rates on low levels. This means our adaptive separation thresholds can effectively balance the safety and operation efficiency of the airspace. INDEX TERMS Unmanned aircraft system (UAS), airspace integration, well clear (WC), self-separation, collision avoidance, separation thresholds, sense and avoid (SAA).

show abstract

Section: B Calculation Of Missing Alarm Rate and False Alarm Ratementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Adaptive Separation Thresholds for Self-Separation of Unmanned Aircraft System in Dynamic Airspace

Zhang

2019

IEEE Access

View full text Add to dashboard Cite

show abstract

“…Recent literature contains several proposed self-separation threshold and well clear definitions [10][11][12][13][14]. Johnson, Mueller, and Santiago detail and compare several of these di↵erent definitions [10].…”

Section: B the Need To Define Well Clearmentioning

confidence: 99%

A Well Clear Recommendation for Small UAS in High-Density, ADS-B-Enabled Airspace

McLain

Duffield

2017

AIAA Information Systems-Aiaa Infotech @ Aerospace

View full text Add to dashboard Cite

With the growing popularity of small unmanned aircraft systems (UAS), there is a significant need to enable small UAS to detect and avoid collisions with both manned and unmanned aircraft. The capabilities of ADS-B make it an attractive sensor for detect and avoid (DAA), but it is susceptible to frequency congestion. This paper quantitatively analyzes the frequency limitations of 978 MHz ADS-B. It then uses these limitations to make a recommendation for well clear in ADS-B-equipped airspace that has a high density of small UAS operations.

show abstract

“…The European Commission's Directorate General for Mobility and Transport (DG MOVE), the European Defence Agency (EDA), the European Aviation Safety Agency (EASA), and the Single European Sky Air Traffic Management (ATM) Research (SESAR) Joint Undertaking (SJU) are also stepping up the efforts to safely accommodate UAS into the European aviation and ATM system [6]. In parallel with these government and industry-led initiatives, the aerospace research community has been continuously working on several challenges of integrating UAS into non-segregated airspaces including separation thresholds and methods for small UAS [7,8], UAS encounter modelling and collision avoidance [9][10][11], 3D obstacle avoidance strategies for UAS [12][13][14][15] dynamic model augmentation [16], Global Navigation Satellite Systems (GNSS) integrity augmentation for UAS [17], surveillance sensor integration in the UAS platform [18,19] and well-clear boundary models for UAS DAA [20][21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Probabilistic Safety Assessment for UAS Separation Assurance and Collision Avoidance Systems

2019

View full text Add to dashboard Cite

The airworthiness certification of aerospace cyber-physical systems traditionally relies on the probabilistic safety assessment as a standard engineering methodology to quantify the potential risks associated with faults in system components. This paper presents and discusses the probabilistic safety assessment of detect and avoid (DAA) systems relying on multiple cooperative and non-cooperative tracking technologies to identify the risk of collision of unmanned aircraft systems (UAS) with other flight vehicles. In particular, fault tree analysis (FTA) is utilized to measure the overall system unavailability for each basic component failure. Considering the inter-dependencies of navigation and surveillance systems, the common cause failure (CCF)-beta model is applied to calculate the system risk associated with common failures. Additionally, an importance analysis is conducted to quantify the safety measures and identify the most significant component failures. Results indicate that the failure in traffic detection by cooperative surveillance systems contribute more to the overall DAA system functionality and that the probability of failure for ownship locatability in cooperative surveillance is greater than its traffic detection function. Although all the sensors individually yield 99.9% operational availability, the implementation of adequate multi-sensor DAA system relying on both cooperative and non-cooperative technologies is shown to be necessary to achieve the desired levels of safety in all possible encounters. These results strongly support the adoption of a unified analytical framework for cooperative/non-cooperative UAS DAA and elicits an evolution of the current certification framework to properly account for artificial intelligence and machine-learning based systems.

show abstract

Dynamic Separation Thresholds for a Small Airborne Sense and Avoid System

Cited by 22 publications

References 2 publications

Adaptive Separation Thresholds for Self-Separation of Unmanned Aircraft System in Dynamic Airspace

Adaptive Separation Thresholds for Self-Separation of Unmanned Aircraft System in Dynamic Airspace

A Well Clear Recommendation for Small UAS in High-Density, ADS-B-Enabled Airspace

Probabilistic Safety Assessment for UAS Separation Assurance and Collision Avoidance Systems

Contact Info

Product

Resources

About