Aircraft Damage Modeling¶

The damage subsystem turns the F-16 from a fixed plant into a time-varying control object. It lets you schedule failures during a simulation — wing tip loss, jammed control surfaces, engine failure, structural changes — and the env recomputes the aircraft's mass, inertia, aerodynamic coefficients, and control-surface effectiveness in real time. The agent under control then faces a different plant from the moment a damage event fires.

Currently supported on the nonlinear F-16 — longitudinal and 6-DoF angular. The same damage_profile API plugs into both env variants and into any controller / RL agent that uses them. The linear F-16, B-747, and other plants are out of scope for now.

Documentation structure¶

This topic is split across three pages:

This page — overview, quick start, and limits.
Implementation and examples — code layout (the three layers: section-based geometry, DamageState + events, runtime physics recompute), built-in scenarios, custom and random profiles, and worked examples of adaptive RL agents iADP and ET-DHP.
Damage modeling mathematics — all formulas: mass / CG / inertia recompute via Huygens-Steiner, strip-theory deltas for the six aerodynamic coefficients, control-surface and engine failure models, and the resulting 6-DoF ODEs with damage.

Quick start¶

import numpy as np

from tensoraerospace.aerospacemodel.f16.nonlinear.damage import (
    WING_STRIKE_LEFT_TIP,
)
from tensoraerospace.envs.f16.nonlinear_angular import NonlinearAngularF16

env = NonlinearAngularF16(
    initial_state=np.zeros(14),
    number_time_steps=2000,
    damage_profile=WING_STRIKE_LEFT_TIP,
    split_stab=True,
)
obs, _ = env.reset()
for _ in range(2000):
    obs, r, term, trunc, info = env.step(np.zeros(4))
    if info.get("damage_events_triggered"):
        print(info["damage_events_triggered"])

A runnable version of this snippet ships at example/failure_demos/f16_damage_dogfight_demo.py.

What is modelled¶

Failure class	What changes	Where described
Section loss (wing, stabilator, vtail)	mass \(m\), wing area \(S\), span \(b\), Mean Aerodynamic Chord (MAC), centre of gravity \(\mathbf{r}_{cg}\), inertia tensor \(\mathbf{J}\), aerodynamic coefficients	code, math
Control-surface failure (jam / efficiency loss / lost)	Control vector \(\mathbf{u}_{cmd} \to \mathbf{u}_{eff}\)	code, math
Engine failure (partial / total)	Effective thrust \(T_{eff}\)	code, math
Structural changes (dropped stores, ice)	\(\Delta\) mass / CG / inertia	code

Limits¶

The linear F-16, B-747, and other models are not yet supported.
Aerodynamic corrections do not capture wake interference or stalled-flow perturbations beyond what the base lookup tables already encode.
Wing flexibility / aeroelastic effects are not modelled.
Cascading failures (one event triggering another) are not yet implemented; schedule them explicitly in the profile.