code/README.md

Reproducing the results of the paper

This folder contains the code that produces the results of Screening Ground Vehicle Controllers via Test Randomization: Sim2Real and Sim2Sim Studies, with the small intermediate files and result records it needs.

Folder	Study	Details
case1/	Case 1: four path-following controllers on the 1/6-scale ART vehicle; Chrono digital twin versus 60 physical runs (Sim2Real)	case1/README_case1.md
case2/	Case 2: PPO goal-reaching policies; reduced-order model (ROM) versus Chrono HMMWV (Sim2Sim)	case2/README_case2.md

Quick start: all tables from the released records (a few minutes, no simulation)

# Case 1: Tables I, IV, V, sensitivity, pair tests, MPC failures (inputs in case1/data, about 10 s)
cd case1
python3.12 -m venv .venv && .venv/bin/pip install -r requirements.txt
PY=.venv/bin/python
$PY analysis/baseline_orders.py data/per_start data/nominal_sim_runs.csv data/baseline_orders.json
$PY analysis/case1_rank_analysis.py data/per_start data/physical_runs.csv data/baseline_orders.json results
$PY mpc_failures/d3_range.py data/per_start data/b01_mpc_first_tick.csv \
    results/mpc_failures.json results/mpc_failure_geometry.png
cd ..

# Case 2: Table VI and all Case 2 numbers (inputs in case2/results and case2/policies, under 2 min)
cd case2
pip install -r requirements.txt
python analyze.py --set A --pool explore
python report_explore.py
python analyze_confirm.py --set B --rom-dir results/rom_B_confirm16 --chrono-dir results/chrono_B_confirm16 \
    --primary confirm --secondary confirm16 --out results/confirm_analysis.json
python behavior_stats.py B confirm16
python posthoc_confirm.py
python report_confirm.py
python paper_numbers.py            # prints every Case 2 number of the paper; writes results/paper_numbers.json

These commands overwrite the released outputs in case1/results/ and case2/results/ with identical files. Tables II and III (physical runs) are computed from the physical logs on GitHub (stage 2 of Case 1). The two case READMEs give the commands of every stage, their inputs, outputs, and runtimes.

Where each result comes from

Paper item	Script	Output
Table I: TR results per offset range (S0-S4)	case1/analysis/case1_rank_analysis.py	case1/results/case1_rank_analysis.json: offset_sweep
Tables II-III: physical runs and nominal simulation	case1/physical/physical_runs.py	case1/results/tables_II_III.{tex,json}
Table IV: TR versus nominal simulation and Monte Carlo	case1/analysis/baseline_orders.py, case1/analysis/case1_rank_analysis.py	case1_rank_analysis.json: method_comparison, physical_pairwise_tests
Table V: ablation by channel	case1/analysis/case1_rank_analysis.py	case1_rank_analysis.json: ablation_by_channel
Case 1 sensitivity (tube, horizon, number of starts) and Hoeffding bound	case1/analysis/case1_rank_analysis.py	case1_rank_analysis.json: tube_horizon_sensitivity, trial_number_sensitivity, hoeffding
MPC failures from large heading errors	case1/mpc_failures/d3_range.py	case1/results/mpc_failures.json
Case 2 design exploration (goal set A)	case2/analyze.py, case2/report_explore.py	case2/results/exploration_tau_table.json, exploration_report.md
Table VI and the Case 2 held-out results	case2/analyze_confirm.py, case2/posthoc_confirm.py, case2/behavior_stats.py	case2/results/confirm_analysis.json, posthoc_confirm.json, behavior_B_confirm16.json; all numbers in paper_numbers.json

The two case READMEs map every number in the text to its output key.

Regenerating the records

The quick start uses the released intermediate files. To regenerate them:

• Case 1 simulation logs: the runner (case1/runner/) runs inside the Docker image named in case1/README_case1.md. The logs that it produced are in simulation_logs/ of this dataset; stage 1 (case1/extract/) turns them into the per-episode tables of case1/data/per_start/.
• Case 1 physical runs: folder 2024/PathFollowingSim2real/TestingData of https://github.com/uwsbel/sbel-reproducibility.
• Case 2: case2/train_all.sh trains the 24 policies (about 50 min each on one CPU core); run_rom.py and chrono_runner.py re-run the ROM and Chrono evaluations (PyChrono). The released policies and records make retraining unnecessary for checking the results.

Licenses

Code in this folder and the four checkpoints in case2/policies/released/ are under the BSD 3-Clause license of the original repository (case2/policies/released/LICENSE). Data and result records are under CC BY 4.0.