Calibration Processes
IMU Calibration from the Drone Transmitter
The configuration menu contains additional options not described above, such as calibration and parachute packing date. The parachute packing date option allows the user to see when their parachute is due to be re-packed (see the "Parachute Pod Deployment Procedures" section for further information on re-packing timelines). The calibration option is used to recalibrate the inertial measurement unit (IMU) of the PRS-M4S.
If the PRS requires frequent recalibration, contact AVSS immediately.
In the event an IMU calibration is required, the following message will become visible on the main screen of the Drone flight transmitter. This is also indicated on the PRS-M4S itself by the status LED, which will flash yellow (see chart at top of the "Status Indications" section).
To properly calibrate the IMU, the PRS-M4S must be rotated through the six physical orientations, with a minimum of five (5) seconds spent in each orientation. The PRS must be kept steady during each five (5) second interval. Note that this actually results in seven (7) changes in orientation. The easiest way to accomplish this is simply to rotate the Drone through each orientation with the PRS-M4S attached, as shown below.
PRIOR TO ROTATING THE DRONE, CHECK THAT THE PRS-M4S IS DISARMED BY ENSURING THAT THE PRS STATUS MESSAGE OUTLINED ABOVE READS "DISARMED".
After an additional thirty (30) seconds, a successful calibration will be signaled by the disappearance of the calibration warning from the main screen of either the Drone transmitter. The LED status light will also change to red to indicate normal operations. If a successful calibration is not indicated, restart the Drone to connect the PRS-M4S with the Drone.
Compass Calibration From the Drone Transmitter
Independently, the Drone may prompt a user that the onboard compass needs to be calibrated. In this case, a user shall simply follow the instructions displayed on the Drone transmitter screen. It is recommended that while calibrating the compass, the PRS-M4S be attached to the Drone to avoid changes to the Drone's magnetic field readings.
WHEN CALIBRATING THE DRONE COMPASS WITH THE PRS-M4S ATTACHED, ENSURE THAT THE DRONE AND PRS GET A FRESH REBOOT BY FIRST POWERING OFF THE DRONE AND ENSURING THE PRS IS OFF, THEN POWERING ON THE DRONE AND ENSURING THE PRS IS TURNED ON. VERIFY THAT THE PRS-M4S IS DISARMED BY CHECKING THE PRS STATUS MESSAGE WINDOW FOR THE "DISARMED" MESSAGE.
IMU Calibration From AVSS Assistant
It is also possible to calibrate the PRS-M4S's IMU by using the "Calibrate Mode" function in AVSS Assistant. To access this feature, click on the “Calibration Mode” button to calibrate the PRS’s sensors. Note that if using this option, there is a 300-second time window to complete the calibration maneuver; otherwise, the calibration is automatically cancelled. Please follow the orientation instructions above.
As with conducting a calibration from the Drone transmitter, imagine the PRS-M4S as being inside of a 3D cube and place the PRS-M4S on every 6 faces of this cube. Keep the PRS-M4S stationary for ten (10 seconds) on every face. In the end, return the PRS to its initial orientation and wait ten (10) seconds. If the calibration is successful, the PRS-M4S will restart. If a successful calibration is not indicated, unplug the PRS from the computer, wait until the PRS turns off, then replug the PRS back into the computer and attempt the calibration again.
Last updated