IMU data strange

[Former user]

Hello, I have used three plugins of IMU libhector_gazebo_ros_imu.so , libgazebo_ros_imu.so . when I use the libgazebo_ros_imu.so, the linear_acceleration value of x and y is near 0, but the value of z changes between 3.+ and -3.+. when I use the libhector_gazebo_ros_imu.so , the linear_acceleration value of x and y is near 0, but the value of z changes 9.+, 13.+ and 21.+ . the imu data of the two plugins is very strange.

when I use the libdbw_mkz_gazebo_vehicle.so plugin, the value of /vehicle/imu/data_raw looks all correct.

It is very strange, Does someone knows why? And how can I get right data , and like /vehicle/imu/data_raw , not the linear_acceleration.