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        玉米免耕播種機(jī)振動(dòng)特性及對(duì)排種器排種性能的影響

        2024-05-30 00:00:00張紅梅張晨明朱晨輝祝英豪李志杰李鵬昌
        關(guān)鍵詞:振動(dòng)

        摘要:為研究玉米免耕播種機(jī)振動(dòng)特性以及振動(dòng)對(duì)排種器漏播指數(shù)和重播指數(shù)的影響,搭建一套由振動(dòng)加速度傳感器、電荷放大器、USB采集卡組成的播種作業(yè)振動(dòng)測試系統(tǒng),在玉米免耕播種機(jī)免耕地表作業(yè)時(shí)進(jìn)行振動(dòng)測試采集播種作業(yè)的振動(dòng)信號(hào)。因田間工作環(huán)境復(fù)雜,使用經(jīng)典濾波法中的IIR濾波器濾除所采集振動(dòng)信號(hào)中其他高頻干擾信號(hào),對(duì)田間采集振動(dòng)信號(hào)進(jìn)行時(shí)域分析,均方值作為時(shí)域分析指標(biāo)值。結(jié)果表明:振動(dòng)加速度均方根隨著作業(yè)速度和旋耕機(jī)轉(zhuǎn)速的增加呈線性增加,旋耕機(jī)轉(zhuǎn)速和作業(yè)速度是引起玉米免耕播種機(jī)振動(dòng)的主要因素,影響順序?yàn)椋盒麢C(jī)轉(zhuǎn)速>作業(yè)速度。使用二次積分法對(duì)田間采集信號(hào)進(jìn)行分析,得出播種機(jī)作業(yè)時(shí)最大振動(dòng)位移為16.004mm,對(duì)振動(dòng)信號(hào)進(jìn)行頻域分析,使用直接法求出功率譜密度。結(jié)果表明:玉米免耕播種機(jī)振動(dòng)頻率主要在0~100Hz之間,頻率分布與旋耕機(jī)轉(zhuǎn)速影響較大。根據(jù)田間振動(dòng)信號(hào)所得工作參數(shù)搭建振動(dòng)試驗(yàn)臺(tái),以播種機(jī)振動(dòng)頻率、振動(dòng)幅值、作業(yè)速度為試驗(yàn)因素,合格指數(shù)、漏播指數(shù)為評(píng)價(jià)指標(biāo)進(jìn)行3因素3水平響應(yīng)面試驗(yàn)。結(jié)果表明:作業(yè)速度、振動(dòng)幅值和振動(dòng)頻率對(duì)合格指數(shù)和漏播指數(shù)影響較為顯著。各因素對(duì)合格指數(shù)影響順序?yàn)椋赫駝?dòng)幅值、作業(yè)速度、振動(dòng)頻率;各因素對(duì)漏播指數(shù)影響順序?yàn)椋赫駝?dòng)幅值、振動(dòng)頻率、作業(yè)速度。研究結(jié)果可為降低玉米免耕播種機(jī)振動(dòng)和優(yōu)化指夾式排種器提供理論參考。

        關(guān)鍵詞:玉米免耕播種機(jī);指夾式排種器;振動(dòng);時(shí)頻分析;排種性能

        中圖分類號(hào):S223

        文獻(xiàn)標(biāo)識(shí)碼:A

        文章編號(hào):2095-5553 (2024) 05-0001-08

        收稿日期:2022年8月31日" 修回日期:2022年12月5日*基金項(xiàng)目:河南省現(xiàn)代農(nóng)業(yè)產(chǎn)業(yè)技術(shù)體系玉米全程機(jī)械化專項(xiàng)(HARS—22—02—G4)

        第一作者:張紅梅,女,1977年生,河南駐馬店人,博士,教授;研究方向?yàn)橹悄苻r(nóng)業(yè)裝備技術(shù)。E-mail: hmzh86022625@sina.com

        通訊作者:朱晨輝,男,1989年生,河南開封人,博士,講師;研究方向?yàn)檗r(nóng)業(yè)機(jī)械化及其自動(dòng)化。E-mail: zhuchenhui@126.com

        Analysis of vibration characteristics of corn no-till seeder and

        its influence on seed metering performance

        Zhang Hongmei, Zhang Chenming, Zhu Chenhui, Zhu Yinghao, Li Zhijie, Li Pengchang

        (College of Mechanical and Electrical Engineering, Henan Agricultural University, Zhengzhou, 450002, China)

        Abstract:

        In order to study the vibration characteristics of maize no-tillage seeder and the influence of vibration on the leakage index and reseeding index of the seeder, a vibration test system composed of vibration acceleration sensor, charge amplifier and USB acquisition card was set up. A vibration test was carried out to collect the vibration signal of the sowing operation during the no-tillage surface operation of the corn no-till planter. Due to the complex working environment in the field, the IIR filter in the classical filtering method was used to filter out other high-frequency interference signals of the collected vibration signals. The time domain analysis was carried out on the vibration signals collected in the field, and the mean square value was used as the time domain analysis index value. The analysis results showed that the root mean square of vibration acceleration increased linearly with the increase of operating speed and rotational speed of rotary tillage, and the rotational speed and operating speed of rotary tillage were the main factors that caused the vibration of corn no-till planter. The order of influence" was: rotary tillage speed gt; working speed. Through using the quadratic integration method to analyze the collected signals in the field, it was concluded that the maximum vibration displacement of the planter was 16.004 mm. The vibration signal was analyzed in the frequency domain, and the power spectral density was obtained by the direct method. The results showed that the vibration frequency of the corn no-till planter was mainly between 0-100 Hz. The frequency distribution and rotary tillage speed had a great influence. According to the working parameters obtained from the field vibration signal, a vibration test bench was built, and the vibration frequency, vibration amplitude and working speed of the seeder were used as test factors, and the pass index and missed seeding index were used as evaluation indicators to conduct a three-factor and three-level response surface test. The analysis results showed that the working speed, vibration amplitude and vibration frequency had significant effects on the pass index and missed broadcast index. The order of the influence of each factor on the qualification index" was: vibration amplitude, working speed and vibration frequency, the order of each factor on the missed seeding index" was: vibration amplitude, vibration frequency and working speed. The research results of this paper can provide theoretical reference for reducing the vibration of maize no-till seeder and optimizing the finger clip seed feeder.

        Keywords:

        corn no-tillage seeder; finger-clip seed metering device; vibration; time-frequency analysis; seeding performance

        0 引言

        玉米免耕播種機(jī)在田間地表的不平度、機(jī)具的振動(dòng)載荷、拖拉機(jī)行走速度等多種因素導(dǎo)致了玉米的均勻性與合格指數(shù)降低[1, 2]。

        近幾年,國內(nèi)外學(xué)者對(duì)振動(dòng)對(duì)播種性能的影響進(jìn)行了研究。張濤等[3]通過對(duì)田間作業(yè)時(shí)免耕播種機(jī)排種器振特性測試與分析,運(yùn)用離散元軟件模擬了玉米種群的運(yùn)動(dòng)規(guī)律。王奇等[4]建立免耕播種機(jī)的振動(dòng)特性模型,求解其穩(wěn)態(tài)振動(dòng)響應(yīng)。Liu等[5]采用正交試驗(yàn)的方法對(duì)播種機(jī)振動(dòng)特性進(jìn)行研究,結(jié)果表明播種機(jī)作業(yè)前進(jìn)速度為7km/h時(shí)振動(dòng)較大。廖宜濤等[6]通過振動(dòng)臺(tái)架試驗(yàn)發(fā)現(xiàn)吸種負(fù)壓和振動(dòng)頻率對(duì)氣力式排種器合格指數(shù)影響較大。黃與霞等[7]通過振動(dòng)試驗(yàn),得出振動(dòng)幅值、作業(yè)速度與振動(dòng)頻率對(duì)勺輪式排種器播種質(zhì)量的影響。

        玉米免耕播種機(jī)在開溝器前增加了圓盤鋸齒開溝器裝置,作業(yè)時(shí)振動(dòng)對(duì)播種質(zhì)量影響較大。本文以帶旋耕刀的免耕播種機(jī)作為研究對(duì)象,通過對(duì)整機(jī)工作原理及結(jié)構(gòu)的分析,采集播種機(jī)實(shí)際田間工作時(shí)的振動(dòng)信號(hào)進(jìn)行振動(dòng)的影響因素分析,并在實(shí)驗(yàn)室搭建振動(dòng)試驗(yàn)臺(tái),探究各因素對(duì)指夾式排種器播種質(zhì)量的影響,為改進(jìn)播種機(jī)整體結(jié)構(gòu)和優(yōu)化指夾式排種器提供理論依據(jù)。

        1 免耕播種機(jī)結(jié)構(gòu)和工作原理

        玉米免耕播種機(jī)如圖1所示。主要由機(jī)架、旋耕裝置、播種排肥裝置和覆土鎮(zhèn)壓裝置組成,由四點(diǎn)懸掛和萬向節(jié)聯(lián)軸器與拖拉機(jī)相連。旋耕裝置采用了圓盤鋸齒開溝器,通過內(nèi)翻刀和外翻刀形成一定夾角,將殘留的秸稈進(jìn)行二次粉碎翻到背壟上,使種子著床到凈土上,保證種子出苗率。播種裝置是由種箱和肥箱、排種器和排肥器、輸種管、開溝器組成。圖2為指夾式排種器結(jié)構(gòu)。

        2 免耕播種機(jī)田間測試

        1) 機(jī)具與地表相關(guān)參數(shù)。2021年6月12日在河南省周口市商水縣河南農(nóng)業(yè)大學(xué)商水試驗(yàn)田進(jìn)行田間測試,前茬作物為小麥,土壤特質(zhì)為潮土,拖拉機(jī)選用CHERY RC1004 4×4輪式拖拉機(jī),機(jī)具與地表相關(guān)參數(shù)見表1。

        2) 測試方法。本次振動(dòng)測試試驗(yàn)使用單向電荷型加速度傳感器,靈敏度為100.08mV/g,加速度可測范圍為-50~+50g,采樣率設(shè)置為1000Hz(采樣時(shí)間間隔為0.001s),PC計(jì)算機(jī)的DAQ軟件控制數(shù)據(jù)采集過程[8]參數(shù)如表2所示。

        3) 試驗(yàn)方案。本次振動(dòng)測試選用加速度傳感器[9],固定在種箱后方,如圖3所示。因機(jī)械式排種器作業(yè)速度最佳在2~6km/h之內(nèi),作業(yè)速度v選擇2km/h、4km/h、6km/h,拖拉機(jī)轉(zhuǎn)速選擇1500~2300r/min。旋耕機(jī)轉(zhuǎn)速n′選擇280~320r/min。

        通過更換拖拉機(jī)不同擋位調(diào)整作業(yè)速度和旋耕機(jī)轉(zhuǎn)速,在拖拉機(jī)帶動(dòng)免耕播種機(jī)平穩(wěn)工作時(shí)開始測試,采集15s的振動(dòng)數(shù)據(jù)。每種工況下進(jìn)行5次重復(fù)試驗(yàn),后續(xù)振動(dòng)信號(hào)由Matlab進(jìn)行濾波和時(shí)頻分析,振動(dòng)測試現(xiàn)場如圖4所示。

        3 振動(dòng)信號(hào)處理

        3.1 濾波處理

        在實(shí)際采集過程中,因大田工作環(huán)境復(fù)雜所以數(shù)據(jù)采集的振動(dòng)信號(hào)包含了很多的噪聲部分,使用經(jīng)典濾波法中的IIR濾波器對(duì)信號(hào)進(jìn)行濾波處理,減少干擾信號(hào)對(duì)真實(shí)數(shù)據(jù)的影響[8]。

        IIR濾波器結(jié)構(gòu)帶有反饋環(huán)路,又稱為遞歸型濾波器。IIR濾波器的N階差分方程如式(1)所示。

        根據(jù)回歸曲線和表中的數(shù)據(jù)可得,影響合格指數(shù)的順序?yàn)椋赫駝?dòng)幅值、作業(yè)速度、振動(dòng)頻率;漏播指數(shù)的順序?yàn)椋赫駝?dòng)幅值、振動(dòng)頻率、作業(yè)速度;為探究試驗(yàn)指標(biāo)和各因素的影響關(guān)系,使用響應(yīng)面法求解各因素之間的交互關(guān)系。固定一個(gè)因素為0水平。得到另外兩因素響應(yīng)面如圖11所示。

        作業(yè)速度和振動(dòng)幅值對(duì)合格指數(shù)有交互作用。當(dāng)振動(dòng)幅值一定時(shí),合格指數(shù)隨著作業(yè)速度的增加而降低,且降低趨勢逐漸增大;當(dāng)作業(yè)速度一定時(shí),合格指數(shù)隨著振動(dòng)幅值的增加而降低,且降低趨勢逐漸減小的。振動(dòng)幅值分別與作業(yè)速度和振動(dòng)頻率對(duì)漏播指數(shù)有交互作用。當(dāng)振動(dòng)幅值一定時(shí),漏播指數(shù)隨著作業(yè)速度的增大而增大,且上升趨勢逐漸增大的;漏播指數(shù)隨著振動(dòng)頻率的增大而增大的,且上升趨勢逐漸增大;當(dāng)作業(yè)速度和振動(dòng)頻率一定時(shí),漏播指數(shù)隨著振動(dòng)幅值的增大而增大的,且上升趨勢是平穩(wěn)增大的。圖12為通過延遲攝影功能拍攝漏種現(xiàn)象。

        根據(jù)各因素對(duì)合格指數(shù)和漏播指數(shù)的影響結(jié)果分析可得,對(duì)比無振動(dòng)和振動(dòng)條件下,振動(dòng)的增加會(huì)使合格指數(shù)明顯減小。對(duì)比三因素發(fā)現(xiàn)振動(dòng)幅值是影響合格指數(shù)和漏播指數(shù)的主要因素,振動(dòng)幅值的增加會(huì)使合格指數(shù)和漏播指數(shù)減小趨勢增大。主要原因?yàn)椋悍N子運(yùn)動(dòng)過程中受到重力、離心力、摩擦力和振動(dòng)所給的豎直力的作用,當(dāng)振動(dòng)幅值增大時(shí),種子所受的垂直加速度增大,使種子從指夾中脫落,產(chǎn)生漏播現(xiàn)象。如何使種子在振動(dòng)條件下不脫落,是優(yōu)化排種器結(jié)構(gòu)的有效途徑。試驗(yàn)結(jié)果為指夾式排種器優(yōu)化提供理論依據(jù)。

        5 結(jié)論

        1) 搭建一套玉米免耕播種機(jī)振動(dòng)測試系統(tǒng),在免耕播種機(jī)工作時(shí)進(jìn)行振動(dòng)測試,并采集振動(dòng)數(shù)據(jù),分析不同作業(yè)速度和不同旋耕機(jī)轉(zhuǎn)速信號(hào)。結(jié)果表明,旋耕機(jī)轉(zhuǎn)速和作業(yè)速度對(duì)振動(dòng)加速度影響較顯著,旋耕機(jī)轉(zhuǎn)速的振動(dòng)加速度均方根最大增大倍數(shù)為1.45,作業(yè)速度的振動(dòng)加速度均方根最大增大倍數(shù)為1.37,旋耕機(jī)轉(zhuǎn)速比作業(yè)速度對(duì)播種機(jī)振動(dòng)更顯著。通過對(duì)振動(dòng)加速度二次積分,播種機(jī)最大振動(dòng)位移為16.004mm。

        2) 不同工況下頻域分析結(jié)果表明,免耕播種機(jī)的振動(dòng)頻率分布在0~100Hz,振動(dòng)頻率分布與旋耕機(jī)轉(zhuǎn)速有關(guān),與作業(yè)速度影響較小,旋耕刀振動(dòng)基頻為28.02~31.98Hz,二倍頻為56.04~63.96Hz,三倍頻為84.06~95.94Hz。在旋耕裝置與播種機(jī)主體之間增加減震裝置是降低播種機(jī)振動(dòng)的有效途徑。

        3) 搭建振動(dòng)試驗(yàn)臺(tái)并開展排種器振動(dòng)試驗(yàn),把作業(yè)速度、振動(dòng)幅值、振動(dòng)頻率作為主要試驗(yàn)因素,合格指數(shù)、漏播指數(shù)作為試驗(yàn)指標(biāo)進(jìn)行三因素三水平響應(yīng)面試驗(yàn)。通過二次回歸正交組合試驗(yàn)可得,作業(yè)速度、振動(dòng)幅值和振動(dòng)頻率對(duì)合格指數(shù)和漏播指數(shù)影響顯著。合格指數(shù)影響順序?yàn)椋赫駝?dòng)幅值、作業(yè)速度、振動(dòng)頻率;漏播指數(shù)的順序?yàn)椋赫駝?dòng)幅值、振動(dòng)頻率、作業(yè)速度。為優(yōu)化指夾排種器關(guān)鍵部件,減小排種器漏播情況提供理論支撐。

        參 考 文 獻(xiàn)

        [1] 伊力達(dá)爾·伊力亞斯, 朱思洪, 徐剛, 等. 拖拉機(jī)前橋懸架參數(shù)匹配及其對(duì)振動(dòng)特性的影響[J]. 農(nóng)業(yè)工程學(xué)報(bào), 2015, 31(10): 29-36.

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