农业工程学报2025，Vol.41Issue(6)：71-79,9.DOI:10.11975/j.issn.1002-6819.202408190
基于小波变换的拖拉机旋耕作业载荷谱同步加速
Synchronous acceleration of the load spectrum for tractor rotary tillage operation based on wavelet transform
摘要
Abstract
Load spectrum has been widely used in indoor reliability tests on quality verification,in order to improve the efficiency and accuracy of tractor products.However,a large amount of time has been occupied by small load cycles in the load spectrum of tractor tillage during operation,leading to long testing,high energy consumption,and low efficiency.Fortunately,the large and extensive load spectrum can be accelerated for the equivalent real lifetime of tractor products.The equivalent load spectrum is called the accelerated load spectrum.Nevertheless,the conventional acceleration of the load spectrum cannot simultaneously accelerate the multiple types of load in real time.In this study,a synchronized acceleration approach was proposed for the load spectrum of tractor rotary tillage using wavelet transform.Loading application experiments were also carried out to verify the synchronously accelerated load spectrum.Firstly,the operation loads of tractor tillage were collected using the peak-over threshold model.The load spectrum of 1-time extrapolated tillage was obtained for the acceleration research.Subsequently,the wavelet transform analysis with Hilbert envelope was implemented to synchronously accelerate the tillage load spectra.Daubechies wavelet basis function(DbN)was used to decompose the load signal.The wavelet coefficients were reconstructed for the wavelet components at different scales.The cumulative sum-of-square of wavelet components was computed to represent the load damage contribution across all scales.A threshold was set to identify the segments with significant damage.As such,the high-damage segments were extracted using Hilbert envelope analysis.Finally,synchronization acceleration was achieved,according to the time-domain synchronicity of the tillage load spectrum.In addition,the pseudo-damage acceleration efficiency(PDAE)index was proposed to evaluate the acceleration efficiency of the load spectrum.Ultimately,the optimal acceleration parameters were then determined suitable for the operation load spectra of tractor tillage.In the power take-off(PTO)torque load spectrum,the Db1 wavelet was used better at a threshold step size of 16 for the acceleration;In the suspension load spectrum,the Db7 wavelet was used better at a threshold step size of 18 for the acceleration.The better synchronization acceleration was achieved for the load spectrum of the 1-time extrapolated tillage,with a time retention ratio of 81.32％for the accelerated load spectrum,a pseudo-damage retention ratio of 98.99％for the PTO torque load spectrum,and a pseudo-damage retention ratio of 97.56％for the suspension load spectrum.A comparison was made on the statistical characteristic parameters from the improved and traditional damage-retention-based acceleration.The comparative results show that the improved acceleration saved 10.07 percentage point in time retention ratio compared to the damage retention method,while retaining the characteristics of load damage,indicating the higher acceleration efficiency.After that,the mean-and amplitude-frequency histograms of the accelerated load spectrum were obtained using rain flow cycle counting.The accuracy of the acceleration was verified to explore the high acceleration efficiency of the wavelet.Finally,a loading bench test was carried out on the tillage load spectrum.A fuzzy PID controller-based loading control algorithm was also proposed for the tillage load spectrum.Bench loading application tests were also conducted using the accelerated tillage load spectrum.The test results indicate that the loading bench shared a response error of-7.53％for the PTO torque load spectrum and a response error of-2.48％for the suspension load spectrum.The overall error of the loading bench for the rotary tillage load spectrum fully met the actual requirements of the loading application.Dynamic loading was achieved under the tillage working conditions.This research can also provide theoretical references and platform support for the tractor load testing and accelerated fatigue reliability test.关键词
拖拉机/载荷谱/小波变换/旋耕作业/载荷加速/加载平台Key words
tractor/load spectrum/wavelet transform/rotary tillage operation/load acceleration/loading bench分类
农业科技引用本文复制引用
王禹,王玲,王书茂,赵俊生,陈雪丽,马铁华..基于小波变换的拖拉机旋耕作业载荷谱同步加速[J].农业工程学报,2025,41(6):71-79,9.基金项目
山西省基础研究计划项目(202203021212158 （）
202303021212185) （）
国家重点研发计划项目(2016YFD0700102) （2016YFD0700102）
