Kinematic Trajectory Generator (KTG) is a medium fidelity wheels off to wheel on 4D trajectory generator that is used for modeling and simulation based validation of trajectory based operational concepts.

KTG, the Kinematic Trajectory Generator, is medium fidelity wheels off to wheel on 4D trajectory generator that is used for modeling and simulation based validation of trajectory based operational concepts. The software is available with a bridge that is used with NASA’s Airspace Concept Evaluation System (ACES). The well documented API is available to ATM users to easily integrate with other simulation framework. KTG is used by NASA for developing and validating concepts applicable to transitional airspace.

KTG describes the motion of each aircraft in two modes: trimmed mode and transition mode. The trimmed mode is governed by the kinematic aircraft data, which is defined by Eurocontrol’s Base of Aircraft Data (BADA)data file derived from nominal aircraft performance. The transition mode describes the motion from one trimmed mode to another. The acceleration/deceleration during transition mode is governed by the designed controller, with acceleration/deceleration constraints computed from the Total Energy Model using the climbing and descent profile in the BADA data.

KTG generated data is validated against ETMS data and high fidelity aircraft models. KTG includes support for 1) VNAV and LNAV trajectories, 2) RNP Trajectory Change Points, 3) MCP and MCDU/FMS based trajectory modification, 4) Nominal and User descent profile, 5) users specified wind and atmosphere models, and 6) high computational performance.

Features & Benefits

KTG is available as a Java based library with documented APIs for integration with third-party simulation tools. KTG uses point mass kinematic model of the aircraft, and uses Eurocontrol’s BADA aircraft performance data to generate nominal LNAV, VNAV and 4D trajectories. It also uses Total Energy Model to generate off-nominal trajectories. KTG APIs offer:

  • Kinematic and Total Energy Model Based Trajectory Generation

  • Based on Aircraft Data (BADA) Aircraft Performance Model (APM)

  • Compliance with Altitude and Required Time of Arrival (RTA) Restrictions

  • Integration with NASA’s ACES for NAS-wide Simulation

  • Compliance with Arrival and Departure (RNAV-RNP) Procedures

  • Variable Time Step for Computational Efficiency

  • Wind, Weight, APRM, and Intent Uncertainty Models

  • Trajectory Prediction Capability

Applications

Model & Simulation Based Concept Validation
Next Gen Concept Development & Analysis
Medium Fidelity Trajectory Prediction with Uncertainty Models for Decision Support and Advisory Tools
Management Function Similar to Target State Commands and Flight Plan Amendment