3D Point movement from MPU9250 or any 9 DOF sensor

[jpatrick62]

Hello,

I was hoping someone who has worked with any of the 9 DOF sensors can help me with this. Using a Teensy with a MPU9250, I create a quaternion from the 9 sensor outputs (accel, gyro, and mag) and
can rotate a 3D WPF object in space with sensor fusion. So that works, but I'm missing how to use the MPU9250 9 DOF output to move the 3D object up, down, left, right, forward or backwards in 3D space. If anyone can point me along I'd really appreciate it...

 

[brtaylor]

Use your quaternion to rotate the accelerometers into an inertial frame, subtract gravity, and integrate twice (once for inertial velocity and again for inertial position). Your solution will be very erroneous, but that's the best you can do without some external reference (i.e. GNSS, speedometer, etc).

 

[jpatrick62]

Thanks brtaylor, but it looks as if there is no accurate way to do this.

 

[brtaylor]

Not without information from additional sensors (i.e. vicom, GNSS, WiFi / Cell signal SLAM, odometer or speedometer, etc).