Study on the Frequency Compensation of the Dynamic Unbalance Signal Extraction for General Hard Bearing Dynamic Balancing Machine

When a dynamic balancing measuring system is equipped with velocity sensor as its vibration pick-up, the output signal of the sensor is proportional to the third power of rotating speed of the balancing operation. Generally a third order low-pass filter circuit is often used to eliminate the influence of rotating speed and suppress the high frequency interference as well. However, the frequency response of third order low-pass filter circuit can’t compensate completely for the response characteristic of the vibration system of balancing machine, which then causes measuring error. So, as a general purpose hard bearing dynamic balancing machine being suitable for a wide speed range, frequency compensation must be conducted. The approach of frequency compensation is classified into two broad types: hardware and software compensation. This paper conducts further research on these two methods to improve the accuracy of the measuring system and proves the accuracy and effectiveness of the two methods by signal simulation and field experiments.