Orientation from wheel based odometry vs IMU
Hi,
I have run some tests using the jackal and ros indigo. I collected the "x,y,z,w" values for the orientation from the wheel based odometry. These are quaternion representations of the orientation of the jackal.
Similar values are printed for the IMU as well. Here are some values which I logged:
//odometry orientation
[ INFO] [1524638957.013930930]:robotorn:x,y,z,w=0.000000,0.000000,0.037674,0.999290
//Imu orientation
[ INFO] [1524638957.013949804]:robotimu:x,y,z=0.000690,-0.000165,-0.987262
Why are the IMU values negative as compared to those of the odometry? Which should we consider while making our calculations?
Regards, rsmitha.
You are comparing the values between a quaternion and euler angles ?
Hi @Delb, I am comparing quaternions for odometry and imu. I did not capture the'w' value for the imu as I forgot to add it to the ROS INFO list.
I find quaternions pretty hard to compare without straight up plotting / drawing them or converting to euler angles. Which one you should use will depend on your application requirements & the quality of the IMU you're using (e.g., is it the onboard IMU?).
Hi.@stevejp, I am using the onboard imu.
and what is your application / goal?