Relay feedback system
PARITYS0 · dim 2No clear winner. The survival gap is under 10 percentage points and the balanced-score gap is under 0.05, so neither SolvSRK nor the best baseline clears the win threshold. Either works - choose on cost, licensing, or integration effort. All verdicts →
Piecewise-smooth switching system; limit cycle from relay nonlinearity
Problem definition
Canonical benchmark implementation
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 _relay_feedback_rhs(t, y):
x1, x2 = y
u = 1.0 if x1 < 0 else -1.0
return np.array([x2, -x2 + u])- Parameters
- No captured parameters; constants are explicit in the RHS excerpt.
- Initial condition
- y(0) = [0.5, 0]
- Horizon
- t ∈ [0, 20]
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.
Fingerprint
Spread: low
Default noise: none
Recommendation snapshot
Clean best: SciPy Radau
Noisy best: SciPy RK23
Coverage
14 solver arms · clean + 5 noise levels
Ranked on survival, precision, and speed
Versions & freeze
Methodology →- Freeze
- 2026-08-13
- libsolvsrk
- 2.3.0
- SciPy
- 1.14
- SUNDIALS
- CVODE (bundled backend)
20 seeds/cell default · 14 arms · TRL 4–5 · simulation-lab validated · this page: Relay feedback system (relay-feedback-system)
Governed SolvTune benchmark freeze; per-arm medians only. RHS definitions and raw trial rows are not published.
Self-reported by Resonix Labs · not independently verified
Results matrix
Pick an objective and a noise level to rank all arms on survival, median SCD, median nfev, and median wall time. Medians across seeds.
Objective
Best overall trade-off of survival, precision, and speed.
Noise level
| # | Solver | Survival | SCD | nfev | Wall | Score |
|---|---|---|---|---|---|---|
| 1 | SciPy RadauSciPy | 100% | - | 518,183 | 7.20 s | 0.809 |
| 2 | SciPy RK45SciPy | 100% | - | 209,222 | 765 ms | 0.809 |
| 3 | SciPy DOP853SciPy | 100% | - | 422,414 | 1.44 s | 0.809 |
| 4 | SciPy RK23SciPy | 100% | - | 111,728 | 519 ms | 0.809 |
| 5 | CVODE BDFexternal | 100% | - | 78,907 | 306 ms | 0.809 |
| 6 | CVODE Adamsexternal | 100% | - | 64,718 | 245 ms | 0.809 |
| 7 | Tsit5external | 100% | - | 317,220 | 18.24 s | 0.809 |
| 8 | Vern7external | 100% | - | 616,712 | 6.73 s | 0.809 |
| 9 | Vern9external | 100% | - | 1,099,618 | 10.13 s | 0.809 |
| 10 | TRBDF2external | 100% | - | 33,670 | 3.93 s | 0.809 |
| 11 | FBDFexternal | 100% | - | 114,025 | 4.52 s | 0.809 |
| 12 | SolvSRK | 100% | - | 181,144 | 376 ms | 0.809 |
| - | SciPy BDFSciPy | 0% | - | - | - | - |
| - | SciPy LSODASciPy | 0% | - | - | - | - |
At Clean, best balanced arm is SciPy Radau · SolvSRK survival 100%.
Values are medians across seeds, measured by Resonix Labs on Resonix hardware and not independently verified; nfev and wall are on reference lab hardware (indicative). Under injected noise only SolvSRK and the SciPy arms are run. How we measure accuracy → · Verification status →
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_relay_feedback_system_2026,
title = {Resonix Evidence Portal: Relay feedback system},
author = {{Resonix Labs (Canada) Inc.}},
year = {2026},
howpublished = {\url{https://resonixusa.com/evidence/problems/relay-feedback-system}},
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.}
}Related
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