Sorry to bother u,,, I got an interesting scene when i test the app_tracking program by pushing a small cart in a flat hallway of my school building..., i get the pose(px,py,pz&qw,qx,qy,qz) result by UDP transportation , and change it to ros-path type, and show it in RViz...The result is interesting that the position-z changes a lot(growing) with going forward ..Previous test in a playground also has the scene, but i think it is the reason that playground is not flat ,imu performance would get worse with the body shake..More interesting is that pz grows with going forward, and decrease with going backward(ahhh...seems like correct, seems like the origin is where zero point,,,Maybe it is because the different gravity parameter between Beijing and Shanghai )...I got some pics showing below..How to avoid this problem?,,,Thank u for your explaination!!