Tilt sensor based on a dual-axis microaccelerometer with maximum sensitivity and minimum uncertainty in the full measurement range

This work presents an approach to enhance the sensitivity and lower the uncertainty of a tilt sensor based on a dual-axis accelerometer. The arctangent function arctan(a₂/a₁) instead of traditional arcsine function arcsin(a₂/g) or arcsin(a₁/g) is used to solve for tilt angle. As a result, the measured sensitivity of tilt angle is kept in the maximum constant value (17.45 mg/°) and the measurement uncertainty is kept in the minimum constant value (0.033° for the tilt sensor of this work) in the measurement range of -90° to +90°. It is also experimentally verified that the solving method has the maximum sensitivity (the average value of 17.74 mg/° with a root mean square of 0.008 mg/°) and minimum uncertainty (the average value of 0.034° with a root mean square of 0.003°) compared with other solving methods in the range of -90° to +90°]. The output of tilt sensor in the range of -90° to+90° and +90° to +270° is axial symmetry about 90°, so it is easy to extend the measurement range to 360°. Therefore, the presented approach is proved to be effective to enhance tilt sensor sensitivity and lower the uncertainty.