Optimization On Vibration Measuring Points Of The Gearbox Based On The Locally Linear Embedding

In order to guarantee the quality of the wind power turbine speedup gearbox produced by DHI·DCW GROUP CO.,LMT,trial operation should be taken under different working conditions.The current arrangement scheme of the vibration measuring points mainly comes from experience and lacks theoretical basis.And the following online monitor also needs to optimize the arrangement scheme to control the cost and raise the accuracy and sensitivity. Therefore,based on the analysis and summarization of the structural characteristics and vibration signal characteristics,a series of experiments of densely covered measuring points are designed to extract the characteristic parameters of the running state.And Locally Linear Embedding(LLE) is used to solve the optimization problem of the vibration measuring points for the first time.Firstly,based on the summarization of the basic theories of rotary machine vibration and analysis of the primary failure modes,failure mechanisms and vibration signal characteristics of the wind power gearbox and its gears and bearings,the vibration characteristic parameters of the running state are extracted from the amplitude domain,time domain and frequency domain,etc,to form the nonlinear dimensionality used in LLE.Secondly,the measuring points are classified based on the analysis of the basic requirement to them.Combined with the transmission characteristic of the simultaneous existence of the planetary transmission and fix axle transmission and structural characteristic, the optional measuring points are selected and a series of experiments of densely covered measuring points are designed to extract the characteristic parameters of the running state.Finally,the LLE is used to solve the optimization problem of the vibration measuring points,which completes the works of neighborhood points searching based on the pertinence of the frequency spectrum,reconstruction of the weighting factor matrix,calculation of the low-dimensional embedding values and automatic calculation with Matlab.The description of the working state in low-dimensionality and the optimization of the arrangement of the vibration measuring points are realized by the nonlinear dimensionality reduction.The Results indicate the arrangement optimization of the vibration measuring points can be solved through the way of extracting characteristic parameters of working state to form the nonlinear dimensionality space and using the LLE to reduce the dimensionality.That provides a new thought and solution for arrangement optimization and similar problems.