Alignment Correction
Multi-axis compensation routine calculates the angular correction factors needed to eliminate cross-talk between orthogonal measurement axes. During factory testing, off diagonal calibration corrects for manufacturing misalignments by ensuring that a force applied strictly to one axis produces zero output on the other two. This procedure is performed on precision rate tables or multi-axis force calibrators to establish the baseline coupling behavior.
Measurement Process
The instrument is mounted on a reference surface and rotated through a sequence of precisely known angles while exposed to a uniform gravity field or angular rate. In a three-axis accelerometer, for example, the calibration system records the output of all three axes at each orientation. This dataset exposes the slight physical tilts of each individual sensor from the ideal orthogonal frame.
Mathematical Adjustment
Software algorithms process the resulting data to generate a decoupling matrix containing the non-zero off-diagonal terms. These values represent the correction factors that must be applied to the raw outputs to resolve the true vector components. In-situ microprocessors multiply each raw measurement vector by this matrix to yield corrected readings in real time, preventing cross-axis acceleration from contaminating the primary telemetry.
This correction is a standard requirement for high-precision navigation instruments.
Verification Metric
Residual cross-talk must remain below the specified limit after calibration.
