This paper presents a new method of interference reduction in tilt measurement with analog accelerometers. The tilt angles are necessary for various fields, including robotics, automation, and biomedical engineering. Measuring the tilt angles, pitch and roll, with analog accelerometers allows us to overcome major limitations of digital sensors; however, the effects of electromagnetic interference should be considered. | Journal of Automation and Control Engineering Vol. 4, No. 6, December 2016 Interference Reduction in Tilt Measurement Based on Changing the Sensor Mounting Method and Calculation Formulas Hung V. Dao and Takashi Komeda Shibaura Institute of Technology, Saitama, Japan Email: nb13503@, komeda@ Trung T. Nguyen Hanoi University of Science and Technology, Hanoi, Vietnam Email: used; the choice depends on the requirements of each application. Using an analog accelerometer has both advantages and drawbacks. The analog accelerometer allows us to overcome some major limitations of digital sensors. If the signals are processed digitally, we can choose any desired sampling rate and resolution by using an external analog to digital converter. The conversions can be synchronized with any following process in case timing is important. If the signals are processed by analog circuits, the response speed can be maximized [5]. In this case, however, we have to consider the effects of electromagnetic interference (EMI) [6]. The single-ended voltages are very sensitive to noise presents on connection wires. Some additional steps or components are required to reduce the influence. Adding a filter will cause a time delay and limit the bandwidth, whereas using shielded cables or preprocessors is not suitable when the space must be minimized [7]. This paper presents a new method of EMI reduction based on changing the mounting orientation of the accelerometer. Instead of using the conventional mounting method, we proposed a new orientation for sensor mounting and new formulas for angle calculation. The appearance of differential voltage in the new equations can reduce the effect of the external noise. The main idea of this study is presented in following sequence. First and foremost, we propose the new mounting orientation based on a special rotation matrix. After that, the corresponding calculation formulas are built. In .
