The AgendaManager Simulation Environment

Overview

The part-task simulator used in AgendaManager development and evaluation models a generic, twin engine turbojet transport aircraft. It is built from components developed at the NASA Langley and NASA Ames Research centers and in our own lab. The aircraft model, autoflight model, and flight management system model were developed in C and C++ as part of the Advanced Civil Transport Simulator by Terry Abbott, Dave Williams, and their colleagues at the NASA Langley Research Center. The primary flight display, horizontal situation display, and other interface components were developed in FORTRAN, C, and C++ by contractors and NASA personnel at the NASA Ames Research Center. We developed system models and an experimenter's console in Smalltalk (VisualWorks 2.5), modified the NASA software, and integrated the components in our own lab. The simulator runs on one to three Silicon Graphics Indigo 2 workstations, depending on configuration.

Simulator Components

The components of the simulator are as follows.

• Aircraft (NASA Langley) A simple point-mass model of a generic, twin-engine transport. Although manual control is possible through a joystick and throttle levers, the simulator software was not designed to be used this way and in our development and evaluation we controlled the aircraft model primarily by means of the autoflight model.
• Autoflight System (NASA Langley) Provides autopilot and authothrust functions with selectable target values for altitude, vertical speed, flight path angle, heading, and speed. Autoflight system functions include the following:
• altitude hold
• vertical speed (for climbing and descending)
• flight path angle (for climbing and descending)
• heading hold
• heading select
• speed select
• speed hold
• LNAV (for lateral guidance provided by the Flight Management System)
• VNAV (for vertical guidance provided by the Flight Management System)
• Flight Management System (FMS, NASA Langley) A reasonably complete and realistic model of a flight path management system such as the Honeywell Flight Management Systems in current Boeing and other aircraft. Provides complete lateral and vertical flight path guidance through the autoflight system's LNAV and VNAV functions. Programmed via the Control Display Unit (CDU), a multi-line alphanumeric display with an alphabetic keyboard.
• Primary Flight Display (PFD, NASA Ames) An integrated, graphic display showing airspeed, altitude, vertical speed, and attitude (pitch, bank, etc.).
• Horizontal Situation Indicator (HSI, NASA Ames) Provides a moving map display, showing the aircraft's position with respect to navigation aids and other geographical information. Shows current FMS flightpath as a series of line segments connecting navigation aid symbols.
• Powerplant (NASA Langley and OSU) Models two turbojet engine. Langley component models thrust and fuel consumption. OSU component calculates N1, N2 and other parameters as linear functions of thrust and models engine fire and engine failure conditions. Parameters shown on a synoptic display.
• Fuel System (OSU) Models two in-wing fuel tanks, fuel booster pumps, fuel heaters, crossfeed lines, and isolation valves. Models fuel flow from tanks to engines and between tanks. Models fuel pump failures and fuel pressure loss. Permits pilot to open and close valves, start and stop pumps, and crossfeed fuel between tanks when a fuel imbalance occurs via a synoptic display (see below).
• Electrical System (OSU) Models AC and two DC electrical systems. Includes submodels for generators, switches, bus connectors. Models generator and bus failures and permits pilot to correct them and reconfigure the system to provide power to all buses via a synoptic display.
• Hydraulic System (OSU) Models hydraulic pumps, lines, and valves. Simulates pump failures and pressure losses and allows pilot to reconfigure system to correct them via a synoptic display.
• Adverse Weather System (OSU) Models engine fuel de-icers, pitot heaters, and airframe de-icing systems. Models aircraft fuel and surface temperatures as functions of ambient temperature and heater/de-icer function. Permits pilot to activate heating/de-icing functions via a synoptic display.
• Engine Indication and Crew Alerting System (EICAS, OSU) Models a subset of the functions of a centralized monitoring and alerting system. Informs the pilot of abnormal conditions until they are corrected. Messages are color- and position-coded based on severity (see below)

Simulator Interface

Below is an illustration of the interface of the part-task flight simulator. Top to bottom, left to right the components are as follows:

• simulator control panel, containing
• simulator controls (RUN/HOLD/EXIT, etc.)
• mode control panel (autoflight controls), set for heading hold (HDG ON), speed hold (IAS ON) and climb thrust (TCMD CLB)
• manual controls (when not using autoflight and not using separate stick/throttles)
• Primary Flight Display (PFD), showing a climbing right turn.
• Horizontal Situation Indicator (HSI) showing position of the aircraft relative to navigational aids. Here it is between Eugene (EUG, not shown) and Corvallis (CVO).
• Engine Indicating and Crew Alerting (EICAS) display showing three messages:
• a generator failure,
• low fuel pressure, and
• an electrical system line contactor problem.
• Fuel System synoptic display, showing the left fuel pump in the right fuel tank failed.