Kohei Funabiki

Cockpit display using tactile sensation

A new cockpit display system using tactile information was proposed. A 6/spl times/4 pin-array-type tactile display device was mounted on an aircraft control stick, and provides a pilot with altitude tracking cue. Results of preliminary pilot-in-the-loop simulation demonstrated that this system could support a pilot in maintaining an assigned altitude with only partial reference to altitude and/or vertical speed instrument indications.

Method of Trajectory Generation for Perspective Flight-Path Display in Estimated Wind Condition

A method to generate a three-dimensional trajectory for a perspective flight-path display to suppress tracking errors and excessive bank angles due to steady wind was devised. The proposed method transforms an original trajectory constructed from straight and arc segments into a clothoidlike trajectory, and then it replaces the arc segments with the results of a fast-time simulation that incorporates a steady wind, which may be acquired by onboard-sensed and/or uplinked information. The offline simulation demonstrates that the modified trajectory suppresses tracking error and excessive bank angles during path-tracking flight. The piloted-flight simulation also showed not only reductions of tracking errors and bank angles but also of subjective workload. The proposed method was integrated into the onboard system of an airborne sequencing and separation assistance experiment, and the function of the modification algorithm was demonstrated using actual wind information acquired by onboard sensors and ground ...

Evaluation of a trajectory-based operations concept for small aircraft: airborne aspect

The National Aerospace Laboratory of Japan (NAL) and the Electronic Navigation Research Institute (ENRI) are researching a new aircraft operations concept, named NOCTARN, based on three-dimensional flight trajectories shared between aircraft and air traffic control (ATC) via digital data link and negotiated using Control Pilot Data Link Communications (CPDLC). It is proposed to incorporate a route modification function that would be invoked each time a route were assigned to modify the predefined trajectory based on wind conditions and aircraft performance in order to improve path tracking in strong wind while avoiding requiring maneuvers that could lead to loss of control. Route modification could also be used to assure separation between aircraft. This paper reports on the investigation by flight simulation into pilot acceptance of the NOCTARN system, the effects of route modification based on wind conditions and CPDLC operation upon manual flight control performance and pilot workload. The results indicate that modified routes successfully reduced path deviation and lowered pilot workload, and that the introduction of CPDLC procedures had no significant impact on manual flight control. Flight experiments further demonstrated that the proposed system and procedure is acceptable to the pilots.

NOCTARN: Trajectory based CNS/ATM concept for small aircraft

The National Aerospace Laboratory of Japan (NAL) and the Electronic Navigation Research Institute (ENRI) are researching a new aircraft operations concept, named NOCTARN, based on adaptable three-dimensional flight trajectories shared between aircraft and air traffic control (ATC). This operational concept aims to reduce the impact of noise while maintaining flight safety and enhancing operational efficiency. At the initial stage of the program, the research focuses on regional airports and small aircraft including helicopters. The program includes the development of an air traffic management system using digital data links, and onboard navigation and guidance systems as well as an ATC console. A flight demonstration involving multiple aircraft and an air traffic controller is planned at the final stage of the project in 2004.

Attention allocation in Tunnel-in-the-Sky on HUD and HDD for visual flight

A series of flight simulations was carried out to investigate the causal factors of attention capture, focusing on a traffic detection task while following a curved trajectory using a Tunnel-in-the-Sky display. Display location (head-up or head-down) and gain were selected as display parameters, and traffic detection time and path tracking performance were measured. The results showed that the HUD gave the best path tracking at the expense of traffic detection performance. The same tendency when using a magnified HDD supports the hypothesis that using a high display gain with a Tunnel-in-the-Sky displays directs much attention to the control task. The present experiment could not identify any differences that might be caused by scanning load due to the location of the display. Also, no tendency of attention capture was observed when the Tunnel-in-the-Sky display was presented on a HDD in comparison with conventional visual (compound) flight.

Evaluating an objective method for motion cueing fidelity

The relationship between the motion fidelity of a flight simulator and pilot handling quality was investigated through a series of pilot-in-the-loop simulations. The phase margin of the aircraft-pilot system during a high gain tracking task was measured while varying the gain and filtering parameters of the motion cueing algorithm, and then compared with Advani-Hosman’s criterion of motion fidelity. Although the results of the simulation are limited to only two axes of the six degrees of freedom, and limited by some hardware limitations, the results partially support the suitability of the criterion of quantifying and qualifying flight simulator motion cueing system.

CDTI design in a trajectory-based operations concept for small aircraft

A CDTI (Cockpit Display of Traffic Information) was developed for a trajectory-based operations concept for small aircraft. The CDTI presents not only the positions of other aircraft but also their trajectories, estimated CPA (Closest Point of Approach) in the case of a conflict, and other related information. Pilot acceptance of the CDTI was evaluated by flight simulation trials. The display symbology was generally accepted and subject pilots easily comprehended the operation of the CDTI. The CDTI enabled the pilots to estimate possible conflicts and to select appropriate trajectories to maintain separation from other traffic. Although traffic situational awareness was enhanced, the introduction of CDTI increased overall pilot workload.

DISTRIBUTED SIMULATION FOR NOCTARN

The National Aerospace Laboratory (NAL) is researching a new aircraft operations concept based on adaptable three-dimensional flight trajectories shared between aircraft and air traffic control (ATC). A flexible, re-usable distributed simulation system incorporating the High Level Architecture (HLA) being constructed as the first step of this research will be used to investigate the concept and to make preliminary examinations of its aircraft operation and ATC procedures. As well as a flight dynamics model, components of the simulation system include a flight crew behavioral model, a pilot interfaces model, and an air traffic control console. This paper describes the construction of the distributed simulation system, and presents the results of numerical simulations using the flight crew behavioral model to demonstrate the proposed concept of operations.

A method of wind shear detection for powered-lift STOL aircraft

A new wind shear warning system for powered-lift STOL aircraft was evaluated by using a flight simulator. Wind shear warning systems for CTOL aircraft have been designed to detect horizontal shear only. Because the approach air speed of STOL aircraft is lower than that for CTOL aircraft, STOL aircraft are more vulnerable to vertical wind due to (1) a gradient of horizontal shear that is smaller for STOL than for CTOL aircraft because of slower airspeed; (2) STOL aircraft spend longer time in a downdraft; and (3) vertical wind causes a more radical change in the STOL aircrafts flight path because of its lower airspeed. In order to detect the vertical wind, the wind shear warning system proposed calculates the difference between potential flight path measured on-board during shear traversal and trimmed flight path estimated from aircraft status. The most characteristic feature of this new system is that it utilizes only inertial information and pitot-static airspeed data; this yields a convenient means of on-board implementation. Simulation test results confirm that the new system can detect the vertical shear.

Pilot workload assessment method in a new CNS/ATM environment

This paper discusses a pilot workload assessment and analysis method used in the development of NOCTARN (new operational concept using three dimensional adaptable route navigation), a concept based on three-dimensional flight trajectories shared between aircraft and air traffic control (ATC) via digital data link and negotiated using controller pilot data link communication (CPDLC). The method, named NAL-WLI, is a subjective mental workload assessment technique based on a modified NASA-TLX (task load index) that focuses on enabling the identification of factors contributing to workload and providing feedback to the NOCTARN environment system design using a scoring method that is easy for pilots. To validate the NAL-WLI method and identify factors contributing to workload in NOCTARN operations, the method was applied to piloted flight experiments using a research airplane and helicopter. Results from NAL-WLI identified factors contributing to workload and the causes of individual differences and provided information for improving the NOCTARN system design.