plane can't runaway take off in HITL mode

[huyandenghuangbo]

I used the pr-hitl-support branch code, I show the detail: the command as follows: then the px4 connect the qgc via udp, I inserted those code to read the accel and gyro in the file of sensor_imu_plugin.cpp in realtime. Like this: I load a fly plan into px4 and run the mission mode, but it can't runaway takeoff. And the accel and gyro data flow Like this: I don't konw where the problem is.