Research On The Multi-point Control Algorithm Of Random Vibration And Software Development Of Virtual Vibration System

Physical vibration test has been one of the main ways to grasp the overall performance ofmechanical or electrical products. Dynamic performance of mechanical or electrical productscan be detected by means of vibration tests, finding out problems timely and making themsolved. But due to the limitation of test conditions, vibration characteristics of productscannot be fully grasped by vibration tests and there may exist over-or under-test problems.Therefore, on the basis of simulation technology, virtual vibration test technology has becomean important development direction of vibration tests to reduce physical vibration tests and itcan even make up the shortcomings of physical vibration tests.In this paper, based on the basic principles of vibration analysis, virtual vibrationalgorithms are studied, which are related to the time-domain analysis of vibration, shockresponse spectrum analysis, or the random vibration analysis. In addition, a virtual vibrationtest software modules is developed.For the impact problems, two methods used to calculate the shock response spectral arestudied, i.e. the Runge-Kutta algorithm and the improved recursive digital filter method. Bysimulation analysis, it can be concluded that the accuracy of the two algorithms is relativelyclose, and the computing efficiency can be improved a lot by the latter method. So theimproved recursive digital filter method is selected to compute the shock response spectrumof impact problems. Meanwhile, for the problems of synthesizing complex shock wave, thebasic principles and application of the fundamental law are studied. A method of usingrandom time delay during the correction process is proposed and it is proved to be able tosynthesize complex shock wave which can better meet the shock response spectralspecification.For the random vibration control problem, issues related to multi-point control arediscussed in detail and causes for control errors are analyzed. Then three most commonlyused control algorithms are introduced. Advantages and existed problems of them are discussed. On this basis, an improved control algorithm is proposed to achieve effectivecontrol of the power spectral density of the control points.Development of the virtual vibration test systems is introduced in detail from thefollowing aspects, which include the software architecture, design of function modules,design and implementation of the key algorithms. By using different types of numericalexamples, the virtual vibration test system is examined. Results under different vibrationconditions get from the system are compared with results computed by software like lmsvirtual.lab, concluding that the analysis results of the developed system are correct.