Traceable World State: A Provenance-Aware State Representation and Deterministic Replay Framework for Robotic Systems
Organizations: Independent Researcher Seattle, WA, USA
Abstract
Robotic systems operating over extended tasks must maintain a world state assembled from observations arriving at different times, with varying confidence and potential revisions. Conventional representations emphasize latest estimates, hindering fact provenance, decision reproduction, or execution auditing. We present Traceable World State (TWS), a middleware-neutral semantic representation and reference runtime for provenance-aware robot world state. A TWS snapshot captures entities, relations, observations, confidence, and revision metadata. Validated update operations transform snapshots immutably, ordered updates support deterministic replay, and a canonical SHA-256 hash chain ensures tamper-evident logs. We evaluate TWS through schema conformance, complete state lifecycles, deterministic replay, and fault injection. Passing 38 tests across Python 3.10-3.14, the framework detects record corruptions, broken hash links, sequence discontinuities, and world mismatches. Across ten public BEHAVIOR-1K task definitions, TWS imported 153 entities and 146 relations with successful validation. On 103 NVIDIA Unitree G1 simulated trajectories containing 78,369 frames, TWS achieved exact terminal-state replay in all episodes and detected 412/412 injected corruptions with a 1.72% storage overhead over Plain JSONL.
Figures & tables
| Element | Purpose |
|---|---|
| World ID | Separates independent state histories. |
| Revision | Orders validated snapshots and rejects stale updates. |
| Entity | Represents a physical, virtual, or conceptual object. |
| Relation | Represents a typed directed edge between two entities. |
| Observation | Records timestamped evidence from a sensor or source. |
| Source | Connects an entity or relation to supporting evidence. |
| Property | Result |
|---|---|
| Valid four-operation lifecycle | Pass |
| Deterministic ordered replay | Pass |
| Input snapshot remains unchanged | Pass |
| Stale update rejection | Pass |
| Missing relation endpoint rejection | Pass |
| Referenced entity removal rejection | Pass |
| Injected fault | Detection result |
|---|---|
| Modified nested update | Detected |
| Modified previous-hash value | Detected |
| Modified sequence number | Detected |
| World identifier mismatch | Detected |
| Base-revision discontinuity | Detected |
| Malformed JSON record | Detected |
| Updates | Validation | Append | Verification | Replay |
|---|---|---|---|---|
| 10 | 1.297 (0.029) | 24.478 (1.207) | 2.944 (0.067) | 9.197 (0.115) |
| 100 | 12.588 (0.169) | 2111.450 (9.887) | 28.260 (0.124) | 91.053 (2.254) |
| 500 | 60.883 (0.573) | 51941.915 (97.959) | 136.578 (1.748) | 438.086 (4.539) |
| Measure | Result |
| BDDL version | 3.6.0 |
| Initial entities | 13 |
| Initial relations | 12 |
| Food objects | 8 |
| Hash-linked event records | 16 |
| Final revision | 16 |
| Measure | Result |
| Available problem0 tasks | 1,016 |
| Eligible task definitions | 1,016 |
| Deterministic sample size | 10 |
| Runtime validation | 10/10 |
| CLI validation | 10/10 |
| Total imported entities | 153 |
| Measure | Result |
|---|---|
| Episodes processed | 103/103 |
| Source frames checked | 78,369 |
| TWS updates recorded | 5,150 |
| Finite and consistent episodes | 103/103 |
| Terminal-state matches | 103/103 |
| TWS corruption detection | 412/412 |