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software [2018/07/21 14:45]
seandepagnier created
software [2018/07/30 20:16] (current)
seandepagnier
Line 23: Line 23:
 === Calibration === === Calibration ===
  
-For the autopilot to work correctly the inertial sensors must be calibrated.   ​Typically this is just an offset or bias for each of the sensors.+For the autopilot to work correctly the [inertial sensorsmust be calibrated.
  
-The gyroscopes continuously automatically update their biasand many sensors ​have accurate accelerometer bias leaving ​the compass which can change widely depending on where it is mounted and what is around it.+Firstthe accelerometers may be calibrated. To calibrate, hold the sensors ​still for a few seconds in each side of the box until calibrated  video link
  
-mpu9250/​mpu9255 ​ --  With yellow capacitor ​the accelerometer ​is already biasedwith orange capacitor accelerometer bias calibration needed.+Next, the IMU must be leveled to the boat.   When it is mounted and secured to the vessellevel the sensors.
  
 +Last, the compass which can change widely depending on where it is mounted and what is around it must be calibrated. ​ There are two possible results, 2D and 3D calibration. ​ If the boat makes a flat circle, only 2D calibration is possible.
 +
 +With 2D compass calibration,​ the heading is only accurate when level.
 +
 +With 3D calibration is accurate when pitching and rolling.
 +
 +To get a 3D calibration suggestions:​
 +* Sail in a circle tacking through the wind with sufficient heeling angle until calibrated ​
 +* Get crude 3d compass calibration before fixing to boat.  Then make circle, and 2d calibration updates 3d calibration.
 +
 +- mpu9250/​mpu9255 ​ --  With yellow capacitor the accelerometer is already biased, with orange capacitor accelerometer bias calibration needed.
 +- LSM9DS0 ​  ​(seems ok)
 +- L3GD20H, LSM303D ​ (seems ok)
  
software.txt ยท Last modified: 2018/07/30 20:16 by seandepagnier