Development and validation of a new interference cancellation method for accelerometers in orientation measurement

In this study, we developed and validated a new interference reduction method for measuring orientation with a three-axis analog accelerometer. In yaw-pitch-roll order (ZYX convention) Euler angles, roll and pitch are commonly used to represent the tilt of an object. Measuring these angles with an analog accelerometer is a good choice if we can suppress electromagnetic interference. However, the existing suppression methods generally require additional hardware or software. In another approach, one angle can be measured with less effect of interference if sensor orientation and calculation formulas are changed; the preliminary idea has been previously introduced. This paper presents a more optimized design which allows computing the roll angle without any disturbance of interference. The immunity is due to the calculation formulas using differential voltages among sensor outputs. Hence, an advantage of the differential signaling technique is taken within the single-ended system. Both simulations and experiments have confirmed the notable efficiency: noise power was reduced 230 times; angle errors were reduced 5-22.5 times, without any additional hardware and software. This study could be useful for systems which require high speed and high resolution with minimum resources.