Use 64-bit microsecond timestamps for MAVLink HIL messages#17
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SendSensorMessages takes the simulation time as a signed 32-bit int, so HIL_SENSOR and HIL_GPS time_usec wrap after 2^31 microseconds, roughly 35 minutes 47 seconds of simulation time. After the wrap PX4 rejects the stale-looking sensor data and long-endurance SITL sessions fall over. Carry the timestamp as uint64_t end to end, matching the width of the MAVLink time_usec fields, and clamp the JSBSim sim-time conversion so a non-finite or negative sim time cannot produce a bogus timestamp. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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Problem
MavlinkInterface::SendSensorMessagestakes the simulation time as a signed 32-bitint, andSensorData::Gps::time_utc_usecis also anint. The MAVLinkHIL_SENSORandHIL_GPStime_usecfields are 64-bit, so the value wraps at 2^31 microseconds — roughly 35 minutes 47 seconds of simulation time. After the wrap, PX4 sees non-monotonic/stale sensor timestamps and long-endurance SITL sessions degrade or fall over.Fix
uint64_tend to end (SendSensorMessages,SensorData::Gps::time_utc_usec), matching the MAVLink field width.sensor_gps_pluginso a non-finite or negative sim time cannot produce a bogus timestamp.Validation
We have been carrying this as a local patch on top of
f37ec25for long-endurance fixed-wing SITL runs (JSBSim + PX4 v1.16/v1.17 lockstep); with it applied, sessions run well past the 36-minute mark with healthy estimator state, and our smoke/metrics gates pass against both PX4 v1.16.2 and v1.17.0.