1eab154847
Polytopic (Nagumo face-by-face LP check) and SOS polynomial
(Prajna-Jadbabaie w/ CSDP) barrier attempts on operation mode.
**Polytopic (barrier_polytopic.jl):** the naive check on
inv2_holds ∩ precursor_tube_bounds fails — 16 of 18 faces can be
crossed under A_cl. This is EXPECTED: safety halfspaces alone form
a set too big for LQR to contract from everywhere. The correct
approach is Blanchini's pre-image iteration (max robustly controllable
invariant set). Sketched in the script; 2-3 days to implement properly.
**SOS (barrier_sos_2d.jl):** a working proof of concept.
CSDP returns OPTIMAL on a 2-state projection of the operation mode
(dn, dT_c) with:
X_entry = |dn| ≤ 0.01, |dT_c| ≤ 0.1
X_unsafe = dn ≥ 0.15 (high-flux-trip direction)
Dynamics = reduced 2×2 A_cl after LQR.
No disturbance (B_w projects to 0 in this subset).
Global decrease condition (-(∇B·f) SOS) instead of Putinar ∂{B=0}.
Result: a degree-4 polynomial B(x) satisfying all three barrier
conditions. Coefficients printed. First non-quadratic barrier
artifact for this plant.
Caveats:
- 2D projection loses precursor coupling.
- Disturbance ignored in this projection.
- Global-decrease is stronger than the Putinar ∂{B=0} condition;
the latter requires bilinear σ_b·B formulation (BMI) and
iterative solvers. Deferred.
- Scaling to 10-state degree-4 gives SDP ~ 1000×1000; CSDP may
choke. Mosek or MOSEK-free SDP (SCS) might handle.
JuMP, HiGHS, SumOfSquares, DynamicPolynomials, CSDP all added to
Project.toml.
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 (
code/): 10-state point kinetic equation + thermal-hydraulics PWR model with bounded steam-generator heat removal as the disturbance input. Controllers, linearization, LQR, reach-tube propagator, Lyapunov barrier — all Julia. - Verification artifacts (
reachability/): predicate concretizations (single source of truth inpredicates.json) and the standalone reach analysis writeup (WALKTHROUGH.md). - Research context (
thesis/): the HAHACS PhD proposal. - Lab journal (
journal/): chronological invention log in LaTeX. - Predicate explorer app (
app/): Pluto.jl notebook bridging FRET predicates and continuous-state halfspaces.
Layout
pwr-hybrid-3-demo/
CLAUDE.md AI-facing context and architecture map
docs/
architecture.md How the layers compose
figures/ Shared figures for thesis + talks
fret-pipeline/ FRET → ltlsynt → AIGER → state machine
code/ Plant model, controllers, reach (all Julia)
reachability/ predicates.json + WALKTHROUGH.md
app/ Pluto.jl predicate explorer
journal/ LaTeX lab notebook
hardware/ Ovation HIL artifacts (TBD)
claude_memory/ Short AI-context notes
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 and reach analysis:
cd code
julia --project=. -e 'using Pkg; Pkg.instantiate()' # first time only
julia --project=. scripts/main_mode_sweep.jl # all 5 DRC modes
julia --project=. scripts/reach_operation.jl # operation-mode linear reach
julia --project=. scripts/barrier_lyapunov.jl # Lyapunov barrier
julia --project=. scripts/barrier_compare_OL_CL.jl # OL vs CL barrier
julia --project=. scripts/reach_heatup_nonlinear.jl # nonlinear heatup (10s cap)
Open the predicate explorer:
cd app
julia --project=. -e 'using Pluto; Pluto.run()'
# Browser opens; navigate to predicate_explorer.jl
Soundness note: the current reach tubes are over-approximations
of the LINEAR model, not sound over-approximations of the nonlinear
plant. See reachability/README.md and reachability/WALKTHROUGH.md.
Prerequisites
- Julia 1.10+ (via
juliaup). - Python 3.10+ (FRET pipeline only).
- Spot for
ltlsynt(brew install spot). - Graphviz for
dot(brew install graphviz). - LaTeX (via
latexmk) for the thesis + journal builds.
Further reading
CLAUDE.md— orientation for AI agents working in this repodocs/architecture.md— how the layers composecode/CLAUDE.md— code architecture, conventions, validity rangecode/README.md— usage and dependenciesreachability/README.md— reach scope, soundness statusreachability/WALKTHROUGH.md— standalone analysis writeupjournal/README.md— journal format conventionsjournal/journal.tex— the journal itself, dated entriesthesis/CLAUDE.md— the thesis project structurefret-pipeline/README.md— FRET naming conventions and pipeline details