# Multi drone setup with Gazebo sensor error **URL:** \ **Category:** PX4 Autopilot\ **Created:** [February 24, 2026, 9:33am UTC](https://discuss.px4.io/t/multi-drone-setup-with-gazebo-sensor-error/48541 "2026-02-24T09:33:21Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![AmandaLyvik](https://discuss.px4.io/user_avatar/discuss.px4.io/amandalyvik/32/21183_2.png) [@AmandaLyvik](https://discuss.px4.io/u/AmandaLyvik)\ **Post date:** [February 24, 2026, 9:33am UTC](https://discuss.px4.io/t/multi-drone-setup-with-gazebo-sensor-error/48541/1 "2026-02-24T09:33:21Z")
I am trying to launch gazebo with multiple drones as described here [Multi-Vehicle Simulation with Gazebo | PX4 Guide (v1.16)](https://docs.px4.io/v1.16/en/sim_gazebo_gz/multi_vehicle_simulation) After launching a single drone using `PX4_SYS_AUTOSTART=4001 PX4_SIM_MODEL=gz_x500 ./build/px4_sitl_default/bin/px4 -i 1` I eventually get a sensor error `ERROR [sensors] Accel #0 fail: TIMEOUT!`. It takes almost 5 minutes for it to show. Starting it using `make px4\_sitl gz\_x500` give the same warnings but not the error. I am not so worried about the warnings as I plan on using MAVROS and not the MicroXRCEAgent. I am new to this and do not know where to begin troubleshooting. INFO [px4] instance: 1 INFO [px4] working directory /home/amanda-lyvik/PX4/PX4-Autopilot/build/px4\_sitl\_default/rootfs/1 * * * | \__\_ \ \ \ / / / | | |/ / \ V / / /| | | \_\_/ / \ / /| | | | / /^\ \ \__\_ | \_| / / |\_/ px4 starting. INFO [px4] startup script: /bin/sh etc/init.d-posix/rcS 1 env SYS\_AUTOSTART: 4001 INFO [param] selected parameter default file parameters.bson INFO [param] importing from ‘parameters.bson’ INFO [parameters] BSON document size 347 bytes, decoded 347 bytes (INT32:15, FLOAT:3) INFO [param] selected parameter backup file parameters\_backup.bson INFO [dataman] data manager file ‘./dataman’ size is 1208528 bytes INFO [init] Gazebo simulator INFO [init] Starting gazebo with world: /home/amanda-lyvik/PX4/PX4-Autopilot/Tools/simulation/gz/worlds/default.sdf INFO [init] Starting gz gui INFO [init] Gazebo world is ready INFO [init] Spawning model INFO [gz\_bridge] world: default, model: x500\_1 INFO [lockstep\_scheduler] setting initial absolute time to 3196000 us INFO [commander] LED: open /dev/led0 failed (22) WARN [health\_and\_arming\_checks] Preflight Fail: ekf2 missing data WARN [health\_and\_arming\_checks] Preflight Fail: No connection to the ground control station INFO [tone\_alarm] home set INFO [uxrce\_dds\_client] init UDP agent IP:127.0.0.1, port:8888 INFO [mavlink] mode: Normal, data rate: 4000000 B/s on udp port 18571 remote port 14550 INFO [mavlink] mode: Onboard, data rate: 4000000 B/s on udp port 14581 remote port 14541 INFO [mavlink] mode: Onboard, data rate: 4000 B/s on udp port 14281 remote port 14031 INFO [mavlink] mode: Gimbal, data rate: 400000 B/s on udp port 13031 remote port 13281 INFO [logger] logger started (mode=all) INFO [logger] Start file log (type: full) INFO [logger] [logger] ./log/2026-02-24/09\_25\_28.ulg INFO [logger] Opened full log file: ./log/2026-02-24/09\_25\_28.ulg INFO [mavlink] MAVLink only on localhost (set param MAV\_{i}_BROADCAST = 1 to enable network) INFO [mavlink] MAVLink only on localhost (set param MAV_{i}\_BROADCAST = 1 to enable network) INFO [px4] Startup script returned successfully pxh\> INFO [mavlink] partner IP: 127.0.0.1 ERROR [mavlink] vehicle\_command\_ack lost, generation 3 → 26 ERROR [mavlink] vehicle\_command\_ack lost, generation 4 → 26 ERROR [mavlink] vehicle\_command\_ack lost, generation 4 → 26 ERROR [mavlink] vehicle\_command\_ack lost, generation 4 → 26 INFO [commander] Ready for takeoff! INFO [uxrce\_dds\_client] synchronized with time offset 1771925124734119us INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/register\_ext\_component\_reply data writer, topiINFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/arming\_check\_request data writer, topic id: 17INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/mode\_completed data writer, topic id: 150 INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/battery\_status data writer, topic id: 20 INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/collision\_constraints data writer, topic id: 2INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/estimator\_status\_flags data writer, topic id: INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/failsafe\_flags data writer, topic id: 91 INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/manual\_control\_setpoint data writer, topic id:INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/message\_format\_response data writer, topic id:INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/position\_setpoint\_triplet data writer, topic iINFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/sensor\_combined data writer, topic id: 217 INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/timesync\_status data writer, topic id: 240 INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/vehicle\_land\_detected data writer, topic id: 2INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/vehicle\_attitude data writer, topic id: 255 INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/vehicle\_control\_mode data writer, topic id: 26INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/vehicle\_command\_ack data writer, topic id: 259INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/vehicle\_global\_position data writer, topic id:INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/vehicle\_gps\_position data writer, topic id: 26INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/vehicle\_local\_position data writer, topic id: INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/vehicle\_odometry data writer, topic id: 274 INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/vehicle\_status\_v1 data writer, topic id: 279 INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/airspeed\_validated data writer, topic id: 14 INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/vtol\_vehicle\_status data writer, topic id: 288INFO [uxrce\_dds\_client] successfully created rt/px4\_1/fmu/out/home\_position data writer, topic id: 123 INFO [uxrce\_dds\_client] time sync converged WARN [timesync] time jump detected. Resetting time synchroniser. WARN [uxrce\_dds\_client] time sync no longer converged INFO [uxrce\_dds\_client] time sync converged WARN [timesync] time jump detected. Resetting time synchroniser. WARN [uxrce\_dds\_client] time sync no longer converged INFO [uxrce\_dds\_client] time sync converged WARN [timesync] time jump detected. Resetting time synchroniser. WARN [uxrce\_dds\_client] time sync no longer converged INFO [uxrce\_dds\_client] time sync converged WARN [timesync] time jump detected. Resetting time synchroniser. WARN [uxrce\_dds\_client] time sync no longer converged INFO [uxrce\_dds\_client] time sync converged WARN [timesync] time jump detected. Resetting time synchroniser. WARN [uxrce\_dds\_client] time sync no longer converged INFO [uxrce\_dds\_client] time sync converged WARN [timesync] time jump detected. Resetting time synchroniser. WARN [uxrce\_dds\_client] time sync no longer converged INFO [uxrce\_dds\_client] time sync converged ERROR [sensors] Accel #0 fail: TIMEOUT! ---
**Author:** ![system](https://discuss.px4.io/uploads/default/original/3X/7/3/73ce918bdcd64854de904f0c8d9ab70ca9723f2a.png) [@system](https://discuss.px4.io/u/system)\ **Post date:** [May 25, 2026, 9:33am UTC](https://discuss.px4.io/t/multi-drone-setup-with-gazebo-sensor-error/48541/2 "2026-05-25T09:33:54Z")
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