Required navigation performance

About: Required navigation performance is a research topic. Over the lifetime, 343 publications have been published within this topic receiving 3477 citations. The topic is also known as: RNP.

Development of required navigation performance (RNP) requirements for airport surface movement guidance and control

Abstract: This paper presents the application of a relatively new concept, Required Navigation Performance (RNP), as a method to determine requirements for aircraft surface movement guidance and control. Currently, navigation standards do not exist for low visibility aircraft operations on runway and taxiway surfaces. Whereas there are enabling technologies under evaluation for aircraft guidance and Air Traffic Control surveillance on the airport surface, there are no performance requirements available to judge the suitability of specific systems. A top-down process is applied, starting with a target level of safety for each surface operation. RNP requirements are allocated to ground and airborne equipment and an approach is presented to validate the RMP allocations using a Functional Hazard Assessment (FHA).

Avionics-Based Integrity Augmentation System for Mission-and Safety-Critical GNSS Applications

Abstract: This paper presents the main results of the research activities carried out by the Italian Air Force Flight Test Centre in collaboration with the University of Nottingham and Cranfield University in the area of GNSS Avionics Based Integrity Augmentation (ABIA). This research included design, integration and experimental flight test activities on the MB-339CD, TORNADO and TYPHOON aircraft, as well as the development of a novel approach to the problem of GNSS ABIA for mission- and safety-critical air vehicle applications and for multi-sensor avionics architectures based on GNSS. As soon as the validity of the ABIA concept was established, a prototype system was developed for use in flight test applications. This system is capable of alerting the pilot when the critical conditions for GPS signal loss are likely to occur, within a specified maximum time-to-alert. In this ABIA prototype, the aircraft on-board sensors provide information on the aircraft relevant flight parameters (navigation data, engine settings, etc.) to an Integrity Flag Generator (IFG), which is also connected to the on-board GPS receiver. The IFG can be incorporated into one of the existing airborne computers or can be a dedicated processing unit. Using the available data on GPS and the aircraft flight parameters, integrity signals are generated which are displayed on one of the cockpit displays and sent to an Aural Warning Generator (AWG). At the same time, the deviation from the ideal flight path is computed taking into account the geometry and the tracking status of the available GPS satellites, together with the flight test mission requirements and the information provided by the onboard avionic sensors. Current research is extending the results obtained from flight tests to the design of a more advanced ABIA system suitable for manned and unmanned aircraft applications. Mathematical models have been developed to describe the main causes of GNSS signal outages and degradation in flight, namely: antenna obscuration, multipath, fading due to adverse geometry and Doppler shift. Adopting these models in association with suitable integrity thresholds and guidance algorithms, the ABIA system is able to generate integrity cautions (predictive flags) and warnings (reactive flags), as well as providing steering information to the pilot and electronic commands to the aircraft/UAV flight control system. These features allow real-time avoidance of safety-critical flight conditions and fast recovery of the required navigation performance in case of GNSS data losses. In other words, this novel ABIA system addresses all three cornerstones of GNSS integrity augmentation in mission- and safety-critical applications: prediction (caution flags), reaction (warning flags) and correction (alternate flight path computation).

Multi-sensor data fusion techniques for RPAS navigation and guidance

Abstract: Integrated Navigation and Guidance Systems (NGS) based only on satellite and other lowcost navigation sensors (e.g., Micro-Electro-Mechanical System (MEMS) based inertial sensors) cannot guarantee the Required Navigation Performance (RNP) in all flight phases of Remotely Piloted Aircraft Systems (RPAS). In this paper, a novel NGS for a small-to-medium size RPAS is presented, which is based on Global Navigation Satellite System (GNSS), Vision Based Navigation (VBN) and other low-cost avionics sensors. Additionally, Aircraft Dynamics Model (ADM) is used to compensate for the MEMS based Inertial Measuring Unit (IMU) sensor shortcomings in high-dynamics attitude determination tasks. Two multi-sensor architectures are compared that are based on an Extended Kalman Filter (EKF) and an Unscented Kalman Filter (UKF) approach for data fusion. The ADM measurements are prefiltered by an UKF to increase the ADM attitude solution validity time. The EKF based VBNIMU- GNSS-ADM (E-VIGA) system and the UKF based system (U-VIGA) performances are evaluated in a small RPAS integration scheme (i.e., AEROSONDE RPAS platform) by exploring a representative cross-section of this RPAS operational flight envelope. Additionally, an error covariance analysis is performed on the Aircraft Dynamics Filter (ADF) using Monte Carlo simulation. The position and attitude accuracy comparison shows that the E-VIGA and U-VIGA systems fulfill the relevant RNP criteria, including precision approach down to CAT-II.

Required Navigation Performance and 3D Paths in High-Traffic ATM Operations

Abstract: This paper describes an operational concept that enables increased airport and airspace capacity through the integration of Flight Management System (FMS) Required Navigation Performance (RNP) capabilities and ground based air traffic management (ATM) automation tools. The concept applies to en route and terminal area operations and uses voice or data link for air/ground communications. This concept is technically feasible for implementation in the 2008-2012 timeframe, assuming that advanced automation tools currently under development are deployed by Air Traffic Service Providers. This near-term step is key to successful transition to the Next Generation Air Transportation System (NGATS), as it will make a concrete step away from tactical controller vectoring to trajectory-based operations. The paper will provide estimates of potential NAS-wide operational benefits of this concept due to increased airport and airspace capacity and increased flight profile efficiency. Airport and airspace capacity is represented in the Boeing National Flow Model (NFM), which is used to assess the potential delay benefits in current and future schedules that can be expected as system capacity is increased. The NFM is used to model the potential increase in airspace capacity that will be enabled by RNP routes and reduced controller workload due to enhanced automation capabilities.

Required navigation performance for connected and autonomous vehicles: where are we now and where are we going?

Abstract: While automotive original equipment manufacturers and IT companies are developing and demonstrating self-driving cars, true autonomy will not be realised in the near future due in part to the techn...