Hello every one, I'm trying to use hector mapping by using hector slam with a hokuyo laser (using urgnode for the laser data) but the result is really awful (precision is so bad and the map shifts from time to time resulting in a bad map. So I tried improving the result by involving odometry and an imu sensor in the process. I followed the instructions in the internet and looked at a launchfile example written by hector and wrote a similar launch file but the mapping is still no good, I have no idea what to do and what I'm doing wrong.
If anyone can help me with a step by step guide I'll be really grateful. I'm attaching my launch file + the imunode that I wrote myself (since I didn't find any simple node). Thanks in forward

P.S: Please read my imunode to see if I'm doing anything wrong in it aswell since I'm not sure about it; It seems like I can't upload a file right now due to my low points so I'm giving a google drive link for them: launch file: https://drive.google.com/open?id=0B4236Zj1qZgVaUo0M3RKSFJIN1E
imumsg.h: https://drive.google.com/open?id=0B4236Zj1qZgVdWIzMWM3TVZ0S0U
imumsg.cpp: https://drive.google.com/open?id=0B4236Zj1qZgVQzVoNUZaTTJOM1k
imumsg_node: https://drive.google.com/open?id=0B4236Zj1qZgVQ2RGOVRoOE9YOE0

PP.S: Here's a sample of a map we got, note that the bottom part of it should be a square but it has shifted as you can see: https://drive.google.com/open?id=0B4236Zj1qZgVeGhSdEtRbkdIb2s