I'm developing an quadcopter as an DIY project.
I'm in nascent stage of development.
I've just finalized the design/working philosophy.
I'm planning to fuse data from 9-DOF (9-Axes) IMU + GNSS + Pressure Sensor using EKF to develop AHRS-INS for my quadcopter.
I was looking into integrated (single chip) 9-DOF IMU (Accelerometer + Magnetometer + Gyroscope) MEMS Sensor IC. I was looking into Bosch Sensortec (BNO055) and TDK (ICM-20948).
TDK ICM-20948 has a status of NRND and has been marked as EOL.
While I was browsing through these IC manufacturers website I realized that most new/recommended sensor ICs for quadcopter/drones are 6-DOF (6-Axes) and not 9-DOF IMU. These modern sensors only house 3-Axes Accelerometer and 3-Axes Gyroscope but no magnetometer.
I wish to know
- if my plan is obsolete whereby I'm plan to use 3-Axes Magnetometer along with help from GNSS to get heading/bearing with respect to true north or any alternate new approach is recommended
- if 6-DOF IMU gives better performance/accuracy compared to 9-DOF IMU and it is recommended to use separate 3-Axes magnetometer in conjunction with 6-DOF IMU rather than a single interated 9-DOF IMU