The Research Of Virtual Test System For Field Balancing

The emergence and rapid development of virtual instrument technology, makesmeasuring instrument and testing technology happen tremendous changes. Comparedwith traditional instrument, the software design has the rich advantages of simpleoperation, friendly interface, and high stability, which users can develop on their own.The development of virtual dynamic balance test system with the computer as itscore,which based on virtual instrument technology, instrument technology, computercommunication technology combined with field balancing technique, not only can savethe cost of developing and testing software, but also can accurately diagnosis the rotorunbalance fault, efficiently and real-timely show the size and position of unbalance,which has become the main research direction of current field dynamic balance test.In order to meet the needs of the development of modern dynamic balance, andimprove balance precision, this thesis developed a virtual field dynamic balance testingsystem by combining virtual instrument technology, digital signal processingtechnology and on-site Balancing technology, and using software development platformVisual Basic6.0.The hardware structure and software design was introduced in thispaper. The hardware mainly included: Working principle of the sensor and preamplifierwas introduced, the data acquisition circuit which based on C8051F340SCM wasdesigned, data communication with PC epistatic machine through the USB interfacewas realized. The software consisted of the vibrational signal analysis module whichincluded the FFT analysis, cepstrum analysis, and of calibration and measurement fordynamic balance which included double-sided dynamic balancing, left (right)single-sided balancing, double-single sided dynamic balancing from adding weight inthe same (reverse) direction.In the actual process of rotor dynamic balance, the rotor is often affected bynonlinear factors. Results of dynamic balance tests using the linear model exist thenonlinear measuring errors, and often repeatedly starting and stopping measurement isneeded in order to satisfy the precision requirement, since there is certain nonlinearbetween the unbalance mass and the vibration response of rotor system Therefore, the effects of the nonlinear factors is considered, the nonlinear relationship between theunbalance mass and the vibration response is elucidated, and a method by using thefirst-order nonlinear identification and correction to test the fan rotor is proposed in thefield. In addition, successive approximation algorithm has been used in the process ofrotor balance to reduce nonlinear factors. Finally, a large number of experiments wereused to analyze the measurement system. Through the experimental analysis hadimproved the performance of each part in the system, the precision and accuracy of fielddynamic balance test.