FeiYu Tech FY-AHRS-2000B - Manual (Page 10)

Guilin Feiyu Electronic Technology Co., Ltd
Guilin Feiyu Electronic Technology Co., Ltd http://www.feiyudz.cn [email protected]
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If necessary, the compensation process can be repeated several times. When began to run
the test program, please note: The magnetic objects (such as the nearby mobile phones, structural
steel and buried underground pipelines) may lead to azimuth errors. If the FY-AHRS-2000B is
installed in a vehicle, it will encounter the magnetic field anomaly; this is why there is a
magnetic compensation procedure. However, for some bulky magnetic properties are very likely
to distort the earth’s magnetic field, even the process of magnetic compensation happened in a
long distance.
Magnetic declination and bias of installation is the most important parameter values, which
can be entered into the module by the host. Usually, when power-on, the module will
automatically set the value of magnetic declination and bias to 0. This can be changed through
software commands, and the value is still valid after restarted.
Magnetic declination (also known as magnetic variable) is the angle between true north and
magnetic north. Azimuth bias is defined as the level angle deviation between the module's
forward axis (X axis) and the reference axis of installation platforms. Azimuth bias is a constant,
which is decided the module mechanical placement and installation elements. Magnetic
declination and Azimuth bias will affect the accuracy of the Azimuth observation. The module
should use these two corrected values, and add it to the magnetic field course deviation angle
correction option.
According to usual practice, both the mark symbol of magnetic declination and azimuth
bias used in the east are belonging to positive sign. For example, if magnetic north is the east of
true north, magnetic declination is positive. For example, the local magnetic declination is -6 °,
the install bias is -2 °, and then the magnetic field course deviation angle correction option
should fill in the 8 °.
Choosing menu "configuration"-> "magnetic calibration procedures", the magnetic
compensation procedures will be start, at the same time, the process and longitude of the
program operation would be shown on the bottom of the main procedures information displayed
window. Magnetic compensation is used to confirm the magnetic attribute of surrounding
environment, and obtaining the factor which is used to compensate the magnetic. If lack of this
amended procedure, the substantial azimuth angle error may occur.
In the implementation of the "Start calibration of XY-axis magnetic field", you need to place
FY-AHRS-2000B horizontally (the X-Y plane of FY-AHRS-2000B is parallel with the ground
level. At the same time, the right side of Z-axis being faced down with the ground water level
vertically), and rotate the module clockwise, keep it stable circular movement. If the
FY-AHRS-2000B is installed in a vehicle, the above steps are completed by rotate the vehicles
slowly on the horizontal ground.