FPGA based self-vibration compensated two dimensional non-contact vibration measurement using 2D position sensitive detector with remote monitoring

This paper describes the design of a real-time non-contact vibration measurement system which can be used to measure both amplitude and frequency of vibration accurately in two dimensions (X-Y plane). This measurement scheme is optical in nature and uses 2D position sensitive detector (PSD) as the primary sensor for measuring the displacement amplitude of vibration directly. For the first time, to the best of our knowledge, a micro-electro-mechanical systems (MEMS) digital accelerometer is integrated on the same platform where the PSD is mounted to nullify the effect of self-vibration. The complete measurement system is configured over National Instruments-field programmable gate array (NI-FPGA), which enables it to be entirely digitalized, stand alone and reconfigurable. The entire system is enabled to be remotely monitored on a mobile phone with the help of NI-Data dashboard android application within the effective range of a Wi-Fi network. This system can very accurately measure the vibration frequency from 20 Hz to 800 Hz for minimum peak to peak amplitude of 6.36 μm along X-axis and 8.54 μm along Y axis with a maximum 0.058% error in measured frequency.