Spanda

ADAS Replay

Mission trace record, deterministic replay, and explainability for intelligent vehicles.

Fixture: examples/solutions/adas/src/highway_drive.trace


Workflow

# Record a drive
spanda sim examples/solutions/adas/src/highway_drive.sd --record

# Deterministic replay
spanda replay examples/solutions/adas/src/highway_drive.trace --deterministic

# Diagnose events in trace
spanda diagnose examples/solutions/adas/src/highway_drive.sd \
  examples/solutions/adas/src/highway_drive.trace

# Explain decisions
spanda explain examples/solutions/adas/src/highway_drive.trace

Replay event types

Event Description Example frame
behavior_tick Behavior loop iteration (loop every) highway_drive.trace, lane_keeping.trace
scheduler_tick Task scheduler frame (task every) sim_record/lane_keep_task.trace
readiness_check Pre-drive go/no-go Score 94, all factors pass
safety_event Lane departure, AEB activation Steering correction applied
sensor_degradation Camera obstruction, radar failure Device + severity
recovery_action Switch sensor, restart provider Passed safety + capability verification
continuity_decision Degraded mode, speed reduction Driver takeover required?
driver_takeover Handoff to driver Audit trail entry

Scenario replay library

Record traces for each simulation scenario:

# Collision / near miss
spanda sim automatic_emergency_braking/aeb.sd --record

# Driver takeover
spanda sim driver_takeover/driver_takeover.sd --record

# Sensor failure + recovery
spanda sim sensor_failure_recovery/camera_failure.sd --record

# Weather degradation
spanda sim src/highway_drive.sd --record --fault weather_degraded

Golden fixtures

Committed traces for CI regression:

Trace Scenario
src/highway_drive.trace Highway pilot behavior loop (20 behavior_tick @ 50ms)
lane_keeping/lane_keeping.trace Lane keeping assist (20 behavior_tick @ 33ms)
sim_record/lane_keep_task.trace Task scheduler golden trace (20 scheduler_tick)
fixtures/*.trace Narrative scenarios (AEB, camera failure, driver takeover)

Smoke script validates deterministic replay: ./scripts/adas_smoke.sh


Control Center replay viewer

Launch Control Center with the ADAS blueprint:

spanda control-center serve \
  --config examples/solutions/adas/spanda.toml \
  --program examples/solutions/adas/src/highway_drive.sd

ADAS dashboard tab includes replay viewer linking to trace files and diagnosis summaries.

API: GET /v1/diagnosis/summary, GET /v1/observability/traces


Assurance integration

Replay references are included in assurance evidence bundles:

spanda compliance report src/highway_drive.sd --profile iso26262

Assurance case evidence: simulation_replay