Problem definition
Zarchan Ch. 3 (3D engagement geometry)
Canonical RHS excerpt from the registered callable used for this benchmark cell. Expand it to verify the state equations; it is not a standalone runnable fixture.
Show canonical RHS excerpt
def rhs(t, y):
rx, ry, rz = y[0], y[1], y[2]
vx_i, vy_i, vz_i = y[3], y[4], y[5]
d = np.empty(6)
R = np.sqrt(rx * rx + ry * ry + rz * rz)
if R < _RANGE_GUARD:
d[:] = 0.0
return d
vx_rel = vx_i - vtx
vy_rel = vy_i - vty
vz_rel = vz_i - vtz
R_dot = (rx * vx_rel + ry * vy_rel + rz * vz_rel) / R
V_c = -R_dot
R2 = R * R
omega_x = (ry * vz_rel - rz * vy_rel) / R2
omega_y = (rz * vx_rel - rx * vz_rel) / R2
omega_z = (rx * vy_rel - ry * vx_rel) / R2
omega_mag = np.sqrt(omega_x**2 + omega_y**2 + omega_z**2)
if omega_mag > _LOS_RATE_CLAMP:
scale = _LOS_RATE_CLAMP / omega_mag
omega_x *= scale
omega_y *= scale
omega_z *= scale
a_x = N * V_c * omega_x
a_y = N * V_c * omega_y
a_z = N * V_c * omega_z
d[0] = vx_rel
d[1] = vy_rel
d[2] = vz_rel
d[3] = a_x
d[4] = a_y
d[5] = a_z
return d- Parameters
- N = 3
- _LOS_RATE_CLAMP = 0.5
- _RANGE_GUARD = 0.1
- vtx = 200
- vty = 30
- vtz = -10
- Initial condition
- y(0) = [5000, 2000, 1000, -250, 0, 0]
- Horizon
- t ∈ [0, 25]
Canonical RHS excerpt captured from the same registered callable used for the published benchmark. Frozen closure values are summarized below; helper imports and solver settings are intentionally omitted.
Cite this page
Replace the access date. Pin the freeze ID and library versions when comparing against a later export. Cite it as what it is — a self-reported vendor benchmark, not an independently verified result. The note field says so; please keep it.
@misc{resonix_evidence_3d_true_pn_engagement_2026,
title = {Resonix Evidence Portal: 3D True PN Engagement},
author = {{Resonix Labs (Canada) Inc.}},
year = {2026},
howpublished = {\url{https://resonix.tech/evidence/problems/3d-true-pn-engagement}},
note = {Self-reported vendor benchmark; internally generated by Resonix Labs and not independently verified. Accessed YYYY-MM-DD. Freeze 2026-08-13; libsolvsrk 2.3.0; SciPy 1.14.}
}TRL 4–5 · simulation-lab validated · 398 problems · 14 solver arms · clean + 5 noise levels
Freeze: 2026-08-13 · scipy 1.14 · libsolvsrk 2.3.0 · Methodology
Self-reported by Resonix Labs · not independently verified · Verification status