72143bcff5
Earlier placeholder claimed ramp-rate limits weren't expressible as
state halfspaces without augmentation. That was wrong: dT_c/dt is
linear in (T_f, T_c, T_cold) directly from pke_th_rhs (no neutronics
coupling), so |dT_c/dt| <= r_max is two clean halfspaces over x.
Coefficients from pke_params:
a_f = hA / (M_c*c_c) = +0.4587 /s
a_c = -(hA + 2*W*c_c)/(M_c*c_c) = -0.9587 /s
a_cold = 2*W*c_c / (M_c*c_c) = +0.5000 /s
Sum = 0 exact (equilibrium when all T's equal).
Limit chosen: +/- 50 C/hr (tech-spec 28 C/hr + transient overshoot
budget). Verified on actual heatup sim: max dT_c/dt = 48.5 C/hr, min
= 0 C/hr. Passes our placeholder but tight — a strict 28 C/hr tech-
spec invariant would be violated by current ctrl_heatup tuning
(overshoot factor ~1.7x during mid-ramp).
Generalized load_predicates.m to accept multi-coefficient halfspace
rows via "row": [[state_idx, coeff], ...] format, in addition to the
existing single-coefficient {state_index, coeff} form. Backward
compatible.
inv1_holds now conjoins fuel_centerline, cold_leg_subcooled, and the
two rate halfspaces. DNBR still not modeled (would need an
augmented predicate with a correlation-based safety margin).
Hacker-Split: Dane asked about heatup rate invariant; realizing
my earlier 'needs state augmentation' claim was wrong and the rate
constraint is already linear. Fix it, verify against actual sim.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
pwr-hybrid-3-demo
Preliminary example for the HAHACS thesis — a verified hybrid controller for a small modular PWR startup. Composes three layers into one demonstrable pipeline:
- Discrete layer (
fret-pipeline/): FRET natural-language requirements → LTL → synthesized AIGER controller → state-machine diagram. - Continuous layer (
plant-model/): 10-state point kinetic equation + thermal-hydraulics PWR model with bounded steam-generator heat removal as the disturbance input. - Research context (
thesis/): the HAHACS PhD proposal that motivates and formalizes the methodology.
Layout
pwr-hybrid-3-demo/
CLAUDE.md AI-facing context and architecture map
docs/
architecture.md How the discrete and continuous layers compose
figures/ Shared figures for thesis + talks
fret-pipeline/ FRET → ltlsynt → AIGER → state machine
plant-model/ PWR point kinetics + thermal-hydraulics
reachability/ Continuous-mode verification (linear-model tube + Lyapunov barrier attempt; see README)
julia-port/ Parallel plant-model port + ReachabilityAnalysis.jl scaffold
hardware/ Ovation HIL artifacts (TBD)
claude_memory/ Session notes by AI agents (distilled up into CLAUDE.md over time)
thesis/ [submodule] PhD proposal
presentations/
2026DICE/ [submodule] DICE 2026 abstract
Quickstart
Clone with submodules:
git clone --recurse-submodules <url>
cd pwr-hybrid-3-demo
Run the controller synthesis pipeline:
cd fret-pipeline
python3 scripts/fret_to_synth.py pwr_hybrid_3.json specs/synthesis_config_v3.json
bash scripts/synthesize.sh specs/synthesis_config_v3.json circuits
python3 scripts/trace_aiger.py circuits/PWR_HYBRID_3_DRC.aag diagrams
dot -Tpng diagrams/PWR_HYBRID_3_DRC_states.dot -o diagrams/PWR_HYBRID_3_DRC_states.png
Run the plant model (MATLAB in plant-model/ — Octave compatibility not tested since the LQR pieces landed):
main % original single-scenario demo (null vs operation)
main_mode_sweep % all five DRC modes back-to-back, writes to ../docs/figures/
test_linearize % Jacobian sanity check, saves linearization for reach
Run the reach artifacts (reachability/):
reach_operation % linear reach tube for operation-mode LQR
barrier_lyapunov % Lyapunov-ellipsoid barrier cert attempt (sweeps weights)
Soundness note: the current reach tube is the LINEAR model's tube;
it is not yet a sound over-approximation of the nonlinear plant. See
reachability/README.md § Soundness status.
Prerequisites
- Python 3.10+
- Spot for
ltlsynt(brew install spot) - Graphviz for
dot(brew install graphviz) - MATLAB or GNU Octave for the plant model
- LaTeX (via
latexmk) for the thesis submodule
Further reading
CLAUDE.md— orientation for AI agents working in this repodocs/architecture.md— how the layers composethesis/CLAUDE.md— the thesis project structurefret-pipeline/README.md— FRET naming conventions and pipeline detailsplant-model/README.md— scenario setup and model equations