In my project, when I test BNO055 Adafruit under stationary state by checking its filtered Imu data under fused mode (NDOF FMC ON), I've found a large offset of linear acceleration. Normally upon my reading from the forum, the acceptable offset would be max. around 0.02m/s^2. However, mine is over 0.1m/^2 in two axes.
For that, you can refer to the following Imu data outputting history under 2 Hz on purpose, where "GYR" means the angular rate, "EUL" the euler angle of absolute orientation, "QUA" the quaternion expression of absolute orientation and "LIN" the linear acceleration. And the IMU sensor as said is placed in stationary state where the z axis is parallel to gravity direction.
"""
GYR x y z; EUL x y z; QUA w x y z; LIN x y z
GYR 0.00 0.00 -0.02; EUL 283.1250 -0.0625 -6.8750; QUA 0.78 -0.05 -0.04 0.62; LIN -0.10 -0.04 -0.11
Sensor reading took 0.002623 seconds
GYR 0.00 0.00 -0.00; EUL 283.3750 0.0000 -6.8750; QUA 0.78 -0.05 -0.04 0.62; LIN -0.13 -0.04 -0.10
Sensor reading took 0.002211 seconds
GYR 0.00 0.00 0.00; EUL 283.3750 0.0000 -6.8750; QUA 0.78 -0.05 -0.04 0.62; LIN -0.14 -0.04 -0.14
Sensor reading took 0.002242 seconds
GYR 0.00 0.00 0.00; EUL 283.3750 0.0000 -6.8750; QUA 0.78 -0.05 -0.04 0.62; LIN -0.15 -0.06 -0.13
Sensor reading took 0.002196 seconds
GYR 0.00 -0.00 -0.00; EUL 283.3750 0.0000 -6.8750; QUA 0.78 -0.05 -0.04 0.62; LIN -0.13 -0.05 -0.13
Sensor reading took 0.002232 seconds
GYR 0.00 0.00 0.00; EUL 283.3750 0.0000 -6.8750; QUA 0.78 -0.05 -0.04 0.62; LIN -0.13 -0.04 -0.13
Sensor reading took 0.002244 seconds
GYR 0.00 0.00 0.00; EUL 283.3750 0.0000 -6.8750; QUA 0.78 -0.05 -0.04 0.62; LIN -0.13 -0.04 -0.14
Sensor reading took 0.002823 seconds
GYR 0.00 0.00 -0.00; EUL 283.3750 0.0000 -6.8750; QUA 0.78 -0.05 -0.04 0.62; LIN -0.13 -0.04 -0.13
Sensor reading took 0.002604 seconds
GYR 0.00 0.00 0.00; EUL 283.3750 0.0000 -6.8750; QUA 0.78 -0.05 -0.04 0.62; LIN -0.13 -0.03 -0.11
Sensor reading took 0.002238 seconds
GYR -0.00 0.00 0.00; EUL 283.3750 0.0000 -6.8750; QUA 0.78 -0.05 -0.04 0.62; LIN -0.13 -0.03 -0.10
Sensor reading took 0.002183 seconds
GYR 0.00 0.00 -0.00; EUL 283.3750 0.0000 -6.8750; QUA 0.78 -0.05 -0.04 0.62; LIN -0.13 -0.06 -0.13
Sensor reading took 0.002234 seconds
GYR 0.00 0.00 -0.00; EUL 283.3750 0.0000 -6.8750; QUA 0.78 -0.05 -0.04 0.62; LIN -0.12 -0.06 -0.12
Sensor reading took 0.004353 seconds
"""
To provide you with more background infos, here is the current status of Imu sensor corresponding to the given Imu output data above, see the following .
"""
BN0055 Information at Wed Sep 7 10:52:07 2022
----------------------------------------------
Chip Version ID = 0xA0
Accelerometer ID = 0xFB
Gyroscope ID = 0x0F
Magnetoscope ID = 0x32
Software Version = 3.17
Operations Mode = NDOF_FMC
Power Mode = NORMAL
Axis Configuration = X==X Y==Y Z==Z (ENU)
Axis Remap Sign = X+ Y+ Z+
System Status Code = Sensor running with fusion algorithm
System Clocksource = Internal Clock (default)
Accelerometer Test = OK
Magnetometer Test = OK
Gyroscope Test = OK
MCU Cortex M0 Test = OK
System Error Code = No Error
Acceleration Unit = m/s2
Gyroscope Unit = rps
Euler Unit = Degrees
Temperature Unit = Celsius
Orientation Mode = Windows
Sensor Temperature = 33°C
----------------------------------------------
Accelerometer Power = NORMAL
Accelerometer Bwidth = 62.5Hz
Accelerometer GRange = 4G
Accelerometer Sleep = event-driven, 0.5ms
----------------------------------------------
Sensor System Calibration = Fully calibrated
Gyroscope Calibration = Fully calibrated
Accelerometer Calibration = Fully calibrated
Magnetometer Calibration = Fully calibrated
"""
Could anyone offer any pointer and help me figure out the problem? Many thanks in advance!
