DESIGN AND MANUFACTURE OF ARTIFICIAL KEYPHASHOR SIGNAL GENERATOR DEVICE FOR SYNCHRONOUS TIME-AVERAGING

• Main Author: ARIF RAHMAN HAKIM (NIM : 13107014); Pembimbing : Utama Dr. Ir. Zainal Abidin, ZAINAL
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/17714
• Institution: Institut Teknologi Bandung

Synchronous time-averaging is a vibration measurement method in time domain which can reduce noise signal. This method requires two types of input signals, vibration signal and trigger signal produced by a keyphasor sensor. In practice, however, trigger signal is not always available because of limitations on the machine being measured. For example, a trigger signal of an intermidiate shaft of a gearbox usually cannot be obtained due to the absence of a visible shaft part. In contrast, the input and output shafts are usually visible so that a keyphasor signal can be generated. This research will focus on the design and manufacture of an artificial keyphasor signal generator capable of producing trigger signal for synchronous time-averaging process. The device is designed to generate artificial keyphasor signal based on the available keyphasor signal from reference shaft and gear ratio data between the hidden shaft and the reference shaft. This device is also designed to have some additional functions such as function to modify signal duty cycle to 50%, function to convert signal level from Bently sensor to digital level, function to select rising or falling edge of input signal as a reference, and function to invert the input signal. The device has an ATMega8535 microcontroller as the main component. Based on the test results performed to the circuit, it can be concluded that the artificial keyphashor signal generator has been successfully manufactured and met the design specifications. The test results at various gear ratios and 10Hz input signal show that the artificial signal has a percentage time delay which is less than 3%. For 1:1 gear ratio, the artificial signal generated has duty cycle error less than 3% when the input signal has frequency range 0,7-170Hz and duty cycle range 1-99%.