Mavros sitl px4

#1

Hello everyone,
I try to use px4 with ros. But when I tried to use “roslaunch px4 posix_sitl.launch”, there was some problems and the information is:
Segmentation Fault
INFO [log] Backtrace: 9
INFO [log] /home/guoxianzhen/Firmware/build/px4_sitl_default/bin/px4(px4_backtrace+0x25) [0x5875c5]
INFO [log] /home/guoxianzhen/Firmware/build/px4_sitl_default/bin/px4() [0x41e8d1]
INFO [log] /lib/x86_64-linux-gnu/libpthread.so.0(+0x11390) [0x7f1481236390]
INFO [log] /home/guoxianzhen/Firmware/build/px4_sitl_default/bin/px4() [0x42d1be]
INFO [log] /home/guoxianzhen/Firmware/build/px4_sitl_default/bin/px4(camera_trigger_main+0x169) [0x42d699]
INFO [log] /home/guoxianzhen/Firmware/build/px4_sitl_default/bin/px4() [0x5e2e1f]
INFO [log] /home/guoxianzhen/Firmware/build/px4_sitl_default/bin/px4() [0x5e42a9]
INFO [log] /lib/x86_64-linux-gnu/libpthread.so.0(+0x76ba) [0x7f148122c6ba]
INFO [log] /lib/x86_64-linux-gnu/libc.so.6(clone+0x6d) [0x7f14804cb41d]

I have succeeded using it before but now i didn’t know how to fix it. Could anyone give me some suggestions?
Thank you.