Remotely Piloted Aircraft System Integration Research Articles

Preliminary Validation Results of a Novel Concept of Operations for RPAS Integration in TMA and at Airports

The paper describes the results of recent research activities carried out to investigate the safe integration of Remotely Piloted Aircraft System (RPAS) into ATC controlled airspace with a focus on Terminal Manoeuvring Areas (TMAs) and airports. The research activities presented in this paper started with the definition of RPAS-specific use cases and the development of a preliminary novel Concept of Operations. This was followed by the definition and the execution of a simulation test plan for the validation of this new operational concept. The validation campaign has been carried out involving aerospace research centres in the Netherlands (Royal NLR), Germany (DLR), and Italy (CIRA), respectively. Different aspects of RPAS integration in the TMA were considered, such as latency of command & control (C2) link and voice communication link, Automatic Take-off and Landing (ATOL) operations, contingency procedures, and handover of control between two different remote pilot stations. The validation exercises were conducted using real-time human-in-the-loop simulation facilities to assess the human performance of both air traffic controllers and remote pilots. The results showed that the proposed novel concept of operations is suitable for the integration of RPAS at TMAs and airports, with 80% of the objectives fully and 20% partially achieved, and acceptable to excellent results regarding acceptance/situational awareness (8.2/9.0 out of 10 points; higher is better) and workload (2.6 out of 10 points; lower is better).

Sesar PJ13 Erica “Enable RPAS Insertion in Controlled Airspace”- Validation experiment for the long-term integration of RPAS in an Italian TMA air traffic scenario

Remotely Piloted Aircraft Systems (RPAS), are increasingly becoming a part of our day-to-day lives. The vast range of possible uses is creating a new industry with a large economic potential. The technological developments are being developed at a much faster pace than that for manned aviation. From an operational perspective, the challenge lies in integrating the worlds of manned and unmanned aircraft in a safe and efficient way allowing both types of aircraft to use the same airspace. This paper is aimed at describing the results of a validation exercise executed in the frame of the SESAR Programme, with the objective to validate the operational and technical means for the integration of certified RPAS in an Italian Terminal Manouvering Area (TMA).

Concept of Operation for integrating RPAS into terminal airspace

Remotely Piloted Aircraft System (RPAS) is a capital issue for the majority of aviation actors nowadays. The integration of RPAS is an extremely demanding task that must be tackled by multiple standpoints: economic, social, technological or environmental among others. U-space is the answer from Europe to design the operation of multiple and different types of RPAS. U-space is a set of novel services designed to support efficient, safe and secure access to airspace, from the very low level to the upper airspace. This paper focuses on the terminal airspace to design the operational concept for the integration of RPAS in conjunction with conventional aircraft and general aviation. This work develops a holistic methodology to analyse the way RPAS integration affect crucial factors and tries to bring to the light different issues that can frustrate their integration. First, we focus on detailing the requirements specified by RPAS legislation. Second, all the requirements are gathered into different categories to perform further analysis. The categorisation identifies navigation, communication, surveillance, air traffic management and control, and safety as crucial categories (security is out of the scope of this study). The results provide for each category a proposal about how to solve the integration and implementation of RPAS in a TMA.

RPAS Automatic ADS-B Based Separation Assurance and Collision Avoidance System Real-Time Simulation Results

Remotely piloted aircraft systems (RPAS) are increasingly becoming relevant actors that are flying through the airspace and will gain much more importance in the future. In order to allow for their safe integration with manned conventional traffic in non-segregated airspaces, in accordance with the overall air traffic management (ATM) paradigm, specific enabling technologies are needed. As is well known, the detect and avoid (DAA) technology is fundamental among the enabling technologies identified as crucial for RPAS integration into the overall ATM system. In the meantime, to support extended surveillance, the universal introduction of cooperative automatic dependent surveillance-broadcast (ADS-B) on-board aircraft is being increasingly implemented because it has the potential to allow for the coverage of the entire airspaces in remote areas not usually covered by conventional radar surveillance. In this paper, experimental results that were obtained through the real-time validation, with hardware and human in the loop (RTS-HIL) simulations, of an automatic ADS-B based separation assurance and collision avoidance system aimed to support RPAS automatic operations (as well as remote pilot decision making) are presented and discussed. In the paper, after an introductory outline of the concept of operations (ConOps) of the system and its architectural organization, in addition to basic information about the main system functionalities, a description of the tests that were carried out is reported, and the obtained results are described and discussed in order to emphasize the performance and limitations of the proposed system. In particular, the obtained quantitative performances are reported and commented on, and the feedback presented by pilots in order to improve the system, e.g., in terms of preferred typology of conflict resolution maneuver elaborated by the system, is described.

Full Integration of Light RPAS into Not Segregated Airspace: Preliminary Safety Analysis for the Implementation of a Risk Model

A general evolution of airspace and air traffic management is ongoing in Europe including significant novelties for manned aviation. The most important one is the full integration of Remotely Piloted Aircraft Systems (RPAS) in the next future and the full integration of automated air vehicles and Driverless Personal Air Vehicles (DPAV) afterwards with manned aircraft. The economic impact of integration of RPAS with manned aircraft into not segregated airspace to perform aerial work is very important. European and worldwide Aviation Authorities and other organizations (EUROCONTROL, JARUS, RTCA, etc.) are working to elaborate new regulations and standards to maintain the current level of safety of aerial operations facing the incoming new entry in the airspace. The implementation of a comprehensive preliminary risk model is deemed to be propaedeutic to any former safety analysis of the new operational scenario: RPAS and manned aircraft flying together into a not segregated airspace. Such risk model is defined in accordance to the Safety Risk Management Pillar of Safety Management System model. The safety analysis for the implementation of the above mentioned preliminary risk model is presented and discussed in this article. Copyright © 2020 Praise Worthy Prize - All rights reserved.

Decision framework for the integration of RPAS in non-segregated airspace

The integration of Remotely Piloted Aircraft System (RPAS) in non-segregated airspace is one of the forthcoming challenges in aviation. This paper develops a decision framework to determine the airways where RPAS should fly. The methodology defines three types of indicators: (1) static indicators based on the geometry of the airspace; (2) dynamic indicators based on the air traffic features; and (3) mixed indicators that combine both static and dynamic indicators. These indicators appraise the airspace state basic elements as airways and crossing points. The decision framework seeks to detect which airways and air corridors – specific Flight Levels (FLs) of an airway – can be fully segregated for the use of RPAS, as well as the airways that favour the integration of RPAS but increasing the risk level. The decision framework is applied to the Spanish upper airspace LECMZGZ from FL 250 to 300. Results conclude there are no airways that permit their use as segregated airways. However, two air corridors at FL 270 allow the segregated integration of RPAS. Moreover, the decision framework detects the airways that favour the integration of RPAS although they would have an impact on the risk level.

Modelling of the reference STARs procedures in the context of RPAS integration in non-segregated airspace

PurposeThis work presents the part of the research in the integration of the remotely piloted aircraft systems (RPAS) in non-segregated airspace. The purpose of this study is to elaborate the reference shape of the Standard Instrument Arrivals (STARs) procedures of controlled airports. The STARs parameters are unique for the aerodromes and depend on navigational aids (NAVAIDs), manoeuvres and aircraft categories. Therefore, the elaboration of reference shapes was advisable in the context of RPAS integration research.Design/methodology/approachThe models were based on the procedure design guidelines by International Civil Aviation Organization. The statistics of existing STARs were prepared using Aeronautical Information Publications to determine the representative procedural parameters. Construction of procedural shapes required to define the nominal flight path and tolerance areas.FindingsIn statistics, the standard deviation of distances was below the determined reference mean values, thus the models were convergent with existing procedures.Research limitations/implicationsThe modelling was limited to initial, intermediate, final and missed approach segments. Arrival segment was not modelled. NAVAIDs include Instrument Landing System Category 1 (in final and missed approach) and very high-frequency omni-directional ranging or global navigation satellite systems (in initial and intermediate approach segments).Practical implicationsPrepared models may be used in research in the integration of the new types of aerial vehicles in existing air traffic management systems.Originality/valueThe reference STARs possess commonly used procedural manoeuvres (straight-in, turn, racetrack and base turn) and different NAVAIDs. The parameters of approach segments were determined as representative of the existing procedures. Moreover, the models are suitable to place at arbitrary origin and runway axis bearing.

Safe RPAS integration in non-segregated airspace

Purpose This paper aims to assess the implications in safety levels by the integration of remotely piloted aircraft system (RPAS). The goal is to calculate the number of RPAS that can jointly operate with conventional aircraft regarding conflict risk, without exceeding current safety levels. Design/methodology/approach This approach benchmarks a calculated level of safety (CLS) with a target level of safety (TLS). Monte Carlo (MC) simulations quantify the TLS based on the current operation of conventional aircraft. Then, different experiments calculate the CLS associated with combinations of conventional aircraft and RPAS. MC simulations are performed based on probabilistic distributions of aircraft performances, entry times and geographical distribution. The safety levels are based on a conflict risk model because the safety metrics are the average number of conflicts and average conflict duration. Findings The results provide restrictions to the number of RPAS that can jointly operate with conventional aircraft. The TLS is quantified for four conventional aircraft. MC simulations confirm that the integration of RPAS demands a reduction in the total number of aircraft. The same number of RPAS than conventional aircraft shows an increase over 90% average number of conflicts and 300% average conflict time. Research limitations/implications The methodology is applied to one flight level of en-route airspace without considering climbing or descending aircraft. Originality/value This paper is one of the most advanced investigations performed to quantify the number of RPAS that can be safely integrated into non-segregated airspace, which is one of the challenges for the forthcoming integration of RPAS. Particularly, Europe draws to allow operating RPAS and conventional aircraft in non-segregated airspace by 2025, but this demanding perspective entails a thorough analysis of operational and safety aspects involved.

Models of the Reference Departure and Arrival IFR Procedures for the Purpose of Research in RPAS Integration in Controlled Airspace

Abstract The air operations in controlled airspace performed according to Instrument Flight Rules (IFR) are composed of three main flight phases, i.e. departure, cruise, arrival. Controlled airspace is divided into the terminal area and en-route airspace. The terminal area encloses the departure and arrival phases while the en-route airspace encloses the cruise phase. The IFR procedures are designed for manned aviation to ensure the safety of air operations. Development of the aviation concerns among others the increase in the number of unmanned aviation operations. Currently, on the European level, there is an on-going, long-term program of integration of the unmanned aviation in the uniform (non-segregated) airspace. This work concerns the research in the integration of the Remotely Piloted Aircraft Systems (RPAS) in the IFR procedures of the controlled airports. The objective was to build the reference models of Standard Instrument Departure and Arrival Procedures (SID and STAR). Basing on the procedure design guidelines the models of procedural nominal track, tolerance area, obstacle clearance area, climb or descend gradient, manoeuvres in SID and STAR were done. The guidelines describe the operational minima thus the statistics of existing procedures was done to select the suitable procedure parameters such as a number of navigational points, segments lengths, altitudes, climb or descent gradients. Reference models of SID include straight departure and turning departure procedures. Reference models of STAR include non-precision approach procedures according to used navigational aids, i.e. GNSS, VOR. The reference procedures were numerically implemented which will be used in the further works on RPAS integration problem by simulations of the RPAS ability to execute of the SID and STAR.

ATC Separation Assurance for RPASs and Conventional Aircraft in En-Route Airspace

Remotely-piloted aircraft systems (RPASs) present interesting and complex challenges for air traffic management. One of the most critical aspects of the integration of RPASs in non-segregated airspace is safety assessments. This paper lays out a methodology for estimating the minimum protection distance (MPD) that is required to avoid potential conflicts between RPASs and conventional aircraft. The MPD determines the final moment that air traffic control may instruct a RPAS to start climbing with a fixed rate of climb (ROC) to avoid separation minima infringement. The methodology sets out a conflict-resolution algorithm to estimate the MPD. It also models the impact of communication, navigation, and surveillance requirements on the MPD. The main difference between RPASs and conventional aircraft is that the former needs additional communication between the RPAS and pilot in the form of a required Comand and Control link performance (RLP). Finally, the authors carried out Monte Carlo simulations to estimate the value of the MPD only for the head-on encounter, which is the worst scenario. The results showed that the main factors affecting the MPD were RLP and ROC. By increasing RLP and decreasing ROC it was possible to reduce the MPD from 28 to 17 nautical miles; however, the variation in the MPD was not linear.

Innovative time-based separation procedures for civil RPAS integration

Purpose This paper aims to suggest feasible solutions to overcome the problem of unmanned aerial vehicles integration within the existing airspace. Design/methodology/approach It envisages innovative time-based separation procedures that will enhance the integration in the future air traffic management (ATM) system of next generation of large remotely piloted aircraft system (RPAS). 4D navigation and dynamic mobile area concepts, both proposed in the framework of Single European Sky ATM Research program, are brought together to hypothesize innovative time-based separation procedures aiming at promoting integration of RPAS in the future ATM system. Findings Benefits of proposed procedures, mainly evaluated in terms of volume reduction of segregated airspace, are quantitatively analyzed on the basis of realistic operational scenarios focusing on monitoring activities in both nominal and emergency conditions. Eventually, the major limits of time-based separation for RPAS are investigated. Practical implications The implementation of the envisaged procedures will be a key enabler in RPAS integration in future ATM integration. Originality/value In the current ATM scenario, separation of RPAS from air traffic is ensured by segregating a large amount of airspace areas with fixed dimensions, dramatically limiting the activities of these vehicles.

How many RPAS can be safely integrated in non–segregated airspace?

The forthcoming integration of Remotely Piloted Aircraft System (RPAS) is one of the cmost omplex challenges for aviation. Europe draws to allow operating RPAS and conventional aircraft in non-segregated airspace by 2025, but this demanding perspective entails a thorough analysis of the different aspects involved. The RPAS integration in non-segregated airspace cannot imply an increase in the safety levels. This paper assesses how the RPAS integration affects safety levels. The goal is to regulate the number of RPAS that can jointly operate with conventional aircraft regarding conflict risk. This approach benchmarks a Calculated Level of Safety (CLS) with a Target Level of Safety (TLS). Monte Carlo (MC) simulations quantify the TLS based on schedules of conventional aircraft. Then, different combinations of conventional aircraft and RPAS provide different CLS. MC simulations are performed based on probabilistic distributions of aircraft performances, entry times and geographical distribution of aircraft. The safety levels are based on a conflict-risk model because the primary metrics are average number of conflicts and average conflict duration. The methodology is applied to one flight level of en-route airspace. The results provide restrictions to the number of RPAS that can jointly operate with conventional aircraft. Particularly, the TLS is quantified for four conventional aircraft and MC simulations provide the combinations of conventional aircraft and RPAS that fulfil the CLS. The same number of RPAS than conventional aircraft shows an increase over 90% average number of conflicts and 300% average conflict time.

RPAS conflict-risk assessment in non-segregated airspace

The efficient and safe introduction of Remotely Piloted Aircraft System (RPAS) in non-segregated airspace requires a thorough assessment of all operational elements. In this paper, we dealt with the safety problem that arises from the integration of RPAS jointly with conventional aircraft in non-segregated airspace. The authors propose a framework and methodology for airspace design and planning purposes based on a conflict-risk method. This method compares a target level of safety (base-scenario without RPAS) with the calculated level of safety (scenario with RPAS). Moreover, the framework proposes an in-depth assessment by identifying geometrical and operational factors that may affect conflict risk. These conflict-risk factors are critical for RPAS integration and must be assessed to detect relations between them and conflict risk. Moreover, we have performed a sensitivity analysis to assess how RPAS average speed affects conflict risk. A real air traffic volume is studied to characterise a conflict-risk indicator, and different permutations to the base-scenario study the RPAS integration all over airways. Results confirm the validity of the methodology for planning purposes and the viability of RPAS integration without a significant impact on safety but with several restrictions to the RPAS airway distribution.

Performance Verification of an Enhanced Traffic Alerting System for RPAS Integration in ATM

This paper describes the current progress in the development of a Detect And Avoid (DAA) system for application to Remotely Piloted Aircraft Systems (RPAS). Indeed, it is widely recognized that the full exploitation of RPAS, as first step toward an autonomous aircraft, is strictly dependent on the development of a DAA system that performs as safe as an on-board pilot can. In this paper, a specific module of the CIRA full DAA system is described, namely, the component that generates an alert condition for remote pilot or other automatic system intervention. Furthermore, the verification and validation approach and related results are discussed.

An Innovative Cloud-based Supervision System for the Integration of RPAS in Urban Environments

This paper proposes the outline of a Cloud-based supervision system for Remotely Piloted Aircraft Systems (RPAS), which are operating in urban environments. The novelty of this proposed concept is dual: (i) a Cloud-based supervision system focusing on safety and robustness, (ii) the definition of technical requirements allowing the RPAS to fly over urban areas, as a possible evolution of drone use in future smart cities. A new concept for the regulatory issues is also proposed, compared with existing worldwide regulations. The Cloud framework is intended to be an automated system for path planning and control of RPAS flying under its coverage, and not limited to conventional remote control as if supervised by a human pilot. Future works will be based on the experimental validation of the proposed concept in an urban area of Turin (Italy).

Human-in-the-Loop Simulation Analysis of Integrated RPAS Operations in Trajectory Based Operations Environment

In this paper, Human-in-the-Loop (HiTL) simulations of Remotely Piloted Aircraft System (RPAS) operations in two different Air Traffic Management (ATM) concepts, conventional radar vectoring and Trajectory Based Operations (TBO), were performed to assess the impacts of RPAS integration in the future ATM environment. TBO concept maximizes the throughput by planning and sharing 4-D trajectories between pilots and controllers, and it is considered one of the key concepts to enable RPASs to operate with manned aircraft in congested airspaces. RPASs are characterized by having communication delay or temporary loss of communication. TBO capability was added to the integrated air traffic simulation system for this study, which was developed in the Inha University. HiTL simulations were performed by a trainee air traffic controller with three scenarios, and the data were analyzed using safety, efficiency, and controller workload metrics. The results suggest that TBO were effective in reducing delays and controller workload while maintaining the level of safety.

A low-cost and high performance navigation system for small RPAS applications

Modern Remotely Piloted Aircraft Systems (RPAS) employ a variety of sensors and multi-sensor data fusion techniques to provide advanced functionalities and trusted autonomy in a wide range of mission-essential and safety-critical tasks. In particular, Navigation and Guidance Systems (NGS) for small RPAS require a typical combination of lightweight, compact and inexpensive sensors to satisfy the Required Navigation Performance (RNP) in all flight phases. In this paper, the synergies attainable by the combination of Global Navigation Satellite System (GNSS), Micro-Electromechanical System based Inertial Measurement Unit (MEMS-IMU) and Vision-Based Navigation (VBN) sensors are explored. In case of VBN, an appearance-based navigation technique is adopted and feature extraction/optical flow methods are employed to estimate the navigation parameters during precision approach and landing phases. A key novelty of the proposed approach is the employment of Aircraft Dynamics Models (ADM) augmentation to compensate for the shortcomings of VBN and MEMS-IMU sensors in high-dynamics attitude determination tasks. To obtain the best estimates of Position, Velocity and Attitude (PVA), different sensor combinations are analysed and dynamic Boolean Decision Logics (BDL) are implemented for data selection before the centralised data fusion is accomplished. Various alternatives for data fusion are investigated including a traditional Extended Kalman Filter (EKF) and a more advanced Unscented Kalman Filter (UKF). A novel hybrid controller employing fuzzy logic and Proportional–Integral–Derivative (PID) techniques is implemented to provide effective stabilisation and control of pitch and roll angles. After introducing the key mathematical models describing the three NGS architectures: EKF based VBN-IMU-GNSS (VIG) and VBN-IMU-GNSS-ADM (VIGA) and UKF based Enhanced VIGA (EVIGA), the system performances are compared in a small RPAS integration scheme (i.e., AEROSONDE RPAS platform) exploring a representative cross-section of the aircraft operational flight envelope. A dedicated ADM processor (i.e., a local pre-filter) is adopted in the EVIGA architecture to account for the RPAS manoeuvring envelope in different flight phases (assisted by a manoeuvre identification algorithm), in order to extend the ADM validity time across all segments of the RPAS trajectory. Simulation results show that the VIG, VIGA and EVIGA systems are compliant with ICAO requirements for precision approach down to CAT-II. In all other flight phases, the VIGA system shows improvement in PVA data output with respect to the VIG system. The EVIGA system shows the best performance in terms of attitude data accuracy and a significant extension of the ADM validity time is achieved in this configuration.

항공관제시뮬레이터를 이용한 항공기간 회피 기동의 위험도 분석

With rapid growth in the technologies and demand of Remotely Piloted Aircraft Systems (RPASs), integration of such systems into the existing airspace system is becoming an issue in many countries. RPAS have different flight performances, communication characteristics, separation assurance mechanisms, and human machine interfaces from manned aircraft. To establish rules and regulations for RPAS integration, it is important to understand the impacts of RPASs on the airspace system. A simulation system that integrates manned aircraft, air traffic control, and RPASs is developed in Inha University to investigate these impacts through Human-in-The-Loop (HiTL) simulations. Three conflict resolution scenarios between a manned aircraft and a Remotely Piloted Aircraft (RPA) were constructed and tested. Human factors such as the response times of pilots and controllers were measured and analyzed as well as the risk of each maneuver.