xcshare：Hydraulic Engineer，生活记录与感想！

现在听歌，感觉都很杂乱，歌曲也开始实施版权收费制度，忽然很怀念以前用磁带放歌的年代。　music heaven 音乐天堂 杂志大约2002年的时候，高中，好朋友收到一本音乐杂志的礼物，里面夹杂着两盘磁带，我和他住在一起，他都还没来得急听，我已经都快把赞新的杂志快翻脏了！ 好兄弟不说那些，相信他也不会归罪与我 这本杂志给我留下了很深的印象，一种有一盘听了没感觉，另一盘被我反复的播放，每首歌都很有意境，其实英文并不好，但调调很上头，难怪音乐不分国界。 后来，大学和工作就很少听到了，歌曲的名字依稀都快忘记了，但音乐的曲子是记在骨子里了，我几乎都记不清楚那本杂志的封面，多年以后，想听，找了半天，觉得这张图片很相似，但并不能确定。记不住杂志的名字和期号，资源自然就不好找，只能根据记忆中的曲子，复原了一下歌曲清单，并下载收藏，整理歌曲的时候，无意中发现了一款复古的磁带播放器，大神级的，很有当年随身听的感觉，简单的修改了一下，这么经典的歌曲，就用它来播放吧！ (手机用户请横屏！)我还很用心的整理个歌词！null01.Sailing Rod Stewart" }I am sailing, I am sailing home again 'cross the sea.I am sailing stormy waters, to be near you, to be free. I am flying, I am flying like a bird 'cross the sky.I am flying passing high clouds, to be near you, to be free.Can you hear me, can you hear me, through the dark night far away?I am dying, forever crying, to be with you; who can say?Can you hear me, can you hear me, through the dark night far away?I am dying, forever, crying to be with you; who can say?We are sailing, we are sailing home again 'cross the sea.We are sailing stormy waters, to be near you, to be free.Oh Lord, to be near you, to be free.02.Kiss From A Rose Seal"}There used to be a graying time all alone on the seaYou became the light on the dark side of meLove remains a drug gets me high, that's how I feelDid you know that when it snows my eyes become enlargedAnd the light that you shine can be seenBaby, I compare you to a kiss from a rose on the greyThe more I get of you, the stranger it feels, yeahNow that your rose is in bloom, a light hits the gloom on the GreyThere is so much a man can tell you, so much he can sayYou remain my power, my pleasure, my pain, babyTo me you're like a growing addiction that I can't denyWon't you tell me is that healthy, babe?But did you know that when it snows, my eyes become enlargedAnd the light that you shine can be seenBaby, I compare you to a kiss from a rose on the greyI've been kissed by a rose on the grey, I've been kissed by a roseThe more I get of you, the stranger it feels, yeahI've been kissed by a rose on the grey (If I should fall...)Now that your rose is in bloom, a light hits the gloom on the GreyThere is so much a man can tell you, so much he can sayYou remain my power, my pleasure, my painTo me you're like a growing addiction that I can't denyWon't you tell me is that healthy, babyBut did you know, that when it snows, my eyes become enlargedAnd the light that you shine can be seenBaby, I compare you to a kiss from a rose on the greyThe more I get of you, the stranger it feels, yeahNow that your rose is in bloom, a light hits the gloom on the GreyNow that your rose is in bloom, a light hits the gloom on the greyYes, I compare you to a kiss from a rose on the greyThe more I get of you, the stranger it feels, yeahNow that your rose is in bloom, a light hits the gloom on the Grey03.the vanishing race air supply"}Sun, I can't slow you downRun, build on sacred groundAll of the leavesd have blown awayGhosts on a distant highwayIn a vanishing raceSleep, if your eyes must closeWeep, over a poisoned roseSoon all the tears will blow awayDust on a distant highwayIn the vanishing raceFly, closer to the sunFight, 'till your world is oneSoon all the stars will burn awayGhosts on a different highwayIn the vanishing raceOh, shall we sleep tonightTake all your dreams and drive awaySmoke on a distant highwayFrom the vanishing raceAll my peopleRespect your Mother EarthThank you for this life and this breathANd all my people's strength04.Music Madonna"}Musicwritten by Madonna and Mirwais Ahmadzai (Spoken:)Hey Mister D.J.Put a record onI wanna dance with my babyDo you like to boogie woogieDo you like my Acid RockHey Mister D.J.Put a record onI wanna dance with my babyAnd when the music startsI never wanna stopIt's gonna drive me crazyMusicChorus:Music makes the people come together[Never gonna stop]Music makes the bourgeoisie and the rebel[Never gonna stop]Don't think of yesterdayAnd I don't look at the clockI like to boogie woogie, uh, uhIt's like riding on the windAnd it never goes awayTouches everything I'm inGot to have it everyday(chorus)Hey Mister D.J.Do you like to boogie woogieDo you like my Acid RockHey Mister D.J.Put a record onI wanna dance with my babyAnd when the music startsI never wanna stopIt's gonna drive me crazyUh, uh, uhDo you like to boogie woogieDo you like my Acid Rock05.Santa Monica Savage Garden"}In Santa Monica in the winter timeThe lazy streets so undemandingI walk into the crowdIn Santa Monica you get your coffee fromThe coolest places on the promenadeWhere people dress just soBeauty so unavoidableeverywhere you turnIt's thereI sit and wonder what am I doing here?But on the telephone line I am anyoneI am anything I want to beI could be a supermodel or Norman MailerAnd you wouldn't know the differenceOr would you?In Santa Monica, all the people gotmodern namesLike Jake or MandyAnd modern bodies tooIn Santa Monica, on the boulevard,You'll have to dodge those in line skatersOr they'll knock you downI never felt so lonely,Never felt so out of placeI never wanted something more than thisBut on the telephone line I am anyoneI am anything I want to beI could be a supermodel or Norman MailerAnd you wouldn't know the differenceOn the telephone line, I am any heightI am any age I want to beI could be a caped crusader, orspace invaderAnd you would know the differenceOr would you?on the telephone line I am anyoneI am anything I want to beI could be a supermodel or Norman MailerAnd you wouldn't know the difference06.you sang to me marc anthony"}I just wanted you to comfort meWhen I called you late last night you seeI was fallin' into loveOh yes, I was crashin' into loveOh of all the words you sang to meAbout life, the truth and bein' free yeaYou sang to me, oh how you sang to meGirl I live off how you make me feelSo I question all this bein' realCuz I'm not afraid to loveFor the first time I'm not afraid of loveOh, this day seems made for you and meAnd you showed me what life needs to beYea you sang to me, oh you sang to meAll the while you were in front of me I never realizedI just can't believe I didn't see it in your eyesI didn't see it, I can't believe itOh but I feel itWhen you sing to meHow I long to hear you sing beneath the clear blue skiesAnd I promise you this time I'll see it in your eyesI didn't see it, I can't believe itOh but I feel itWhen u sing to meJust to think you live inside of meI had no idea how this could beNow I'm crazy for your loveCan't believe I'm crazy for your loveThe words you said you sang to meAnd you showed me where I wanna beYea you sang to me, oh you sang to me07.Don't Cry For Me Argentina Madonna"}It won't be easy, you'll think it strangeWhen I try to explain how I feelThat I still need your love after all that I've doneYou won't believe meAll you will see is a girl you once knewAlthough she's dressed up to the ninesAt sixes and sevens with youI had to let it happen, I had to changeCouldn't stay all my life down that hillLooking out of the window, staying out of the sunSo I chose freedomRunning around trying everything newBut nothing impressed me at allI never expected it toDon't cry for me ArgentinaThe truth is I never left youAll through my wild daysMy mad existenceI kept my promiseDon't keep your distanceAnd as for fortune, and as for fameI never invited them inThough it seemed to the world they were all I desiredThey are illusionsThey're not the solutions they promised to beThe answer was here all the timeI love you and hope you love meDon't cry for me Argentina......Don't cry for me ArgentinaThe truth is I never left youAll through my wild daysMy mad existenceI kept my promiseDon't keep your distanceHave I said too much? There's nothing more I can thinkof to say to youBut all you have to do is look at me to know that everyword is true08.Babe Take That"}BabeTake ThatI come to your doorto see you againBut where you once stoodwas an old man insteadI ask where you'd beHe said she's moved on you seeAll I have is a numberYou'd better ask her not meSo I picked up the phone and dialled your numberNot sure to put it down or speak Then a voice I once knew answered in a sweet voiceShe said 'hello' then pausedbefore I began to speakBabe , I'm here againI tell you I'm here againWhere have you beenBabe , I 'm back againI tell you I'm back againWhere have you beenYou held your voice wellThere were tears I could tellBut where were you nowwas you gonna tell me in timeJust give me a townand I'll be straight downI got so much to tell you about where I have beenAs I walk down your roadCan't wait to be near you I can't keep this feeling in insideAs I stand at your door You answer in a sweet voiceYou say 'hello' then paused before I began to speakAs I looked awayI saw a face behind you A little boy stood at your door and as I looke againI saw his face with shiningHe had my eyesHe had my smile Babe , I'm back againI tell you I'm back againI 'm here for youBabe , please take me back take me backBack home againBabe , please hold my closehold me closeLike you used to doBabe......09.Shape Of My Heart Sting"}He deals the cards as a meditation And those he plays never suspect He doesn't play for the money he wins He don't play for respect He deals the cards to find the answer The sacred geometry of chance The hidden law of a probable outcome The numbers lead a dance I know that the spades are the swords of a soldier I know that the clubs are weapons of war I know that diamonds mean money for this art But that's not the shape of my heart He may play the jack of diamonds He may lay the queen of spades He may conceal a king in his hand While the memory of it fades I know that the spades are the swords of a soldier I know that the clubs are weapons of war I know that diamonds mean money for this art But that's not the shape of my heart That's not the shape......the shape of my heartAnd if I told you that I loved you You'd maybe think there's something wrong I'm not a man of too many faces The mask I wear is one Well, those who speak know nothin' And find out to their cost Like those who curse their luck in too many places And those who fear are lost I know that the spades are the swords of a soldier I know that the clubs are weapons of war I know that diamonds mean money for this art But that's not the shape of my heart That's not the shape of my heart That's not the shape......the shape of my heart10.bitch Meredith Brooks"}I hate the world todayYou're so good to me, I know but I can't changeTried to tell you but you looked at me like maybe I'm an angel underneathInnocent and SweetYesterday I criedYou must have been relieved to see the softer sideI can understand how you'd be so confusedI don't envy you I'm a little bit of everything, all rolled into oneBrooks Meredith(Chorus)I'm a bitch, I'm a lover, I'm a child, I'm a mother,I'm a sinner, I'm a saintI do not feel ashamedI'm your hell, I'm your dream,I'm nothin in between,You know you wouldn't want it any other way.So take me as I amThis may mean you'll have to be a stronger manRest assured that when I start to make you nervous And I'm goin to extremes Tomorrow I will change and today won't mean a thingJust when you thinkYou got me figured outThe season's already changingI think it's cool,You do what you doAnd don't try to save me(Chorus 2x)I'm a bitch, I'm a teaseI'm a goddess on my kneesWhen you're hurt, when you sufferI'm your angel undercoverI've been numb, I'm revivedCan't say I'm not aliveYou know I wouldn't want it any other way.....11.Sunny Came Home Shawn Colvin"}Sunny came home to her favorite roomSunny sat down in the kitchenShe opened a book and a box of toolsSunny came home with a missionShe says days go by I'm hypnotizedI'm walking on a wireI close my eyes and fly out of my mindInto the fireSunny came home with a list of namesShe didn't believe in transcendenceIt's time for a few small repairs she saidSunny came home with a vengeanceShe says days go by I don't know whyI'm walking on a wireI close my eyes and fly out of my mindInto the fireGet the kids and bring a sweaterDry is good and wind is betterCount the years, you always knew itStrike a match, go on and do itDays go by I'm hypnotizedI'm walking on a wireI close my eyes and fly out of my mindInto the fireLight the sky and hold on tightThe world is burning downShe's out there on her own and she's alrightSunny came homeSunny came home...12.That's Why You Go Away Michael Learns"}Baby won't you tell me why there is sadness in your eyesI don't wanna say goodbye to youLove is one big illusion I should try to forgetbut there is something left in my headYou're the one who set it up now you're the one to make it stopI'm the one who's feeling lost right nowNow you want me to forget every little thing you saidbut there is something left in my headI won't forget the way you're kissingThe feeling's so strong were lasting for so longBut I'm not the man your heart is missingThat's why you go away I knowYou were never satisfied no matter how I triedNow you wanna say goodbye to meLove is one big illusion I should try to forgetbut there is something left in my headI won't forget the way you're kissingThe feeling's so strong were lasting for so longBut I'm not the man your heart is missingThat's why you go away I know yes I knowSitting here all alone in the middle of nowhereDon't know which way to goThere ain't so much to say now between usThere ain't so much for youI won't forget the way you're kissingThe feeling's so strong were lasting for so longBut I'm not the man your heart is missingThat's why you go away I know13.looking for the summer chris rea"}Look deep inside the april faceA change is clearly taking placeLooking for the summerChris ReaThe eyes take on a certain gazeAnd leave behind the springtime daysGo looking for the summerThis ain't no game of kiss and tellThe implications how you know so wellGo looking for the summerTo play the passion out that haunts you soLooking for the summerRemember love how it was the sameWe scratched and hurt each others growing painsWe were looking for the summerAnd still i stand this very dayWith a burning wish to fly awayI'm still looking, looking for the summer14.jesus to a child michael george "}Kindness in your eyesI guess you heard me cryYou smiled at meLike Jesus to a childI'm blessed, I knowHeaven sent and heaven stoleYou smiled at meLike Jesus to a childAnd what have I learnedFrom all this pain?I thought I'd never feel the sameAbout anyoneOr anything againBut now I knowWhen you find loveWhen you know that it existsThen the lover that you missWill come to youOn those cold, cold nightsMichael GeorgeWhen you've been lovedWhen you know it holds such blissThen the lover that you kissedWill comfort youWhen there's no hope in sightSadness in your eyesNo one guessed, or no one triedYou smiled at meLike Jesus to a childLoveless and coldWith your last breath you saved my soulYou smiled at meLike Jesus to a childAnd what have I learnedFrom all theseI've waited for you all those yearsAnd just when it beganHe took your love awayBut I still sayWhen you find loveThen the lover that you missWill come to youOn those cold, cold nightsWhen you've been lovedWhen you know it holds such blissThen the lover that you kissedWill comfort youWhen there's no hope in sightSo the words you could not sayI'll sing them for youAnd the love we would have madeI'll make it for twoFor every single memoryHas become a part of meYou will always beMy loveWell, I've been lovedSo I know just what love isAnd the lover that I kissedIs always by my sideOh the lover I still missWas Jesus to a child{/collapse}

概述：　一个电液伺服作动器（舵机）的测试项目，涉及到电液伺服阀的特性参数定义，比如：压力增益 、零位、零偏和零漂、分辨率、内漏、控制流量、空载流量曲线、名义流量曲线、流量增益、名义流量增益、线性度、对称度、滞环、遮盖、瞬态响应、频率响应。　这一堆堆的概念看的我云里雾里，书面定义的解释往往都比较“冷淡”，但很严禁和准确，仔细想想也能理解，它喜欢用一些逻辑思维和专业术语来描述。但作为我，看完了概念，头脑一阵晕，不知道在讲什么？ : [/A:汗] 　还好，不懂不可怕，但不能妥协，想尽办法搞定它，咱可以进入学习模式...　电液伺服阀特性，你半天不能理解也算正常，因为这些概念覆盖了：电气、液压、数学等学科，基础还需要很不错，才真正理解学习。正文　本文，我会根据我的理解，重新进行整理描述，也算时我的笔记了，以下内容不仅仅是视频内容，还进行了一些扩展内容。压力增益 Pressure Gain压力增益定义：　当控制流量为零时，负载压降对输入电流的变化率。解释：　将伺服阀的AB口，用压力传感器堵死，给伺服阀输入一个完整的正负信号，让阀芯走完全程，会得出横坐标为输入电流I，纵坐标为AB口压力变化P的曲线：然后，我们取±40%额定压力区域内的负载压力和输入电流关系曲线的平均斜率，就是压力增益。零位、零偏和零漂 Null,Null Bias,Null Shift零位定义：　负载压降为零时，是控制流量为零的输入出级相对几何位移。解释：　就是伺服阀没有通电，没有通液（四个油口全部堵死），自然状态下，阀芯的初始位置，就是零位。零偏定义：　在规定试验条件下，调好伺服阀的零点，经过一段时间后，由于阀的结构尺寸，组件应力，电性能等可能使它发生微小变化，即输入电流为零时，输出流量不为零，零点发生了变化。为使输出流量为零，必须预置某一电流，即零偏电流。解释：　正常情况下，当伺服阀没有输入信号时，伺服阀AB口不应该有流量输出（注意，非泄露的流量），但事实上，当伺服阀存在零偏现象后，伺服阀AB口，总会有流量输出。这就是零偏，为了消除零偏，就需要施加一定的电信号，使得伺服阀AB口没有流量输出，这个施加的电流信号，就是零偏电流。（AB方向取平均值）如何测试操作：A.活塞处于全缩位，观察活塞运动情况，给舵机施加逐渐增加负信号，当活塞开始伸缩，减小电流，活塞停止，记录该电流值；（比如： 0.14mA，参考数据）B.活塞处于全伸位，观察活塞运动情况，给舵机施加逐渐增加正信号，当活塞开始缩回，减小电流，活塞停止，记录该电流值；（比如：+0.16mA，参考数据）C.将上面A、B步骤的记录值相加，取平均值，就是该舵机的零偏电流值：比如：零漂定义　因压力、温度等工作条件的变化而引气的零偏的变化，以额定电流的百分比表示。解释：　受到工作环境（供油压力、回油压力、系统温度）的影响，导致了伺服阀存在了零偏现象，这个就是零漂。判定伺服阀零漂合格的要求：　一般规定，供油压力变化为供油压力的±20%，零漂值应小于额定电流的2%；　回油压力从0~0.7MPa变化时，零漂值应小于额定电流的2%；　温度变化范围从 30~+135℃时，零漂值应小于额定电流的4%；调零　超出以上值时，就需要调零的动作，两种方式，一种是电气调零，另一种是机械调零，电气调零很容易理解，这里就不提了，机械调零，见下图，伺服阀专门会有一个调零螺钉，注意，不要超过一圈，如果超过一圈都还没满足要求，那就要另找原因了。　机械调零其实也很容易理解，就是调整喷嘴挡板的初始偏移角度来进行补偿。 分辨率(门限/阈值) Threshold分辨率(门限/阈值)定义：　是伺服阀的输出产生变化所需的最小输入电流之增量，以额定电流的百分比表示。解释：　就是使活塞杆可以移动的最小电流值（伸缩取平均值）和额定电流值的百分比。如何测试操作：　伸出活塞位置在3.8 5.1mm（避免活塞在极限位置）,　A.逐渐调节电流，当活塞杆外伸时，记录其电流值和极性，比如 0.01mA（参考数据）　B.逐渐调节电流，当活塞杆回缩时，记录其电流值和极性，比如+0.03mA（参考数据）　C.将上面A、B步骤的记录值相减，取平均值，就是该舵机的门限电流值：比如：内漏 Internal Leakage内漏定义：　伺服阀控制流量为零时，从进油口到回油口的内部流量，它随进油口压力和输出电流的变化而变化。解释：　伺服阀AB口堵死，P口供压，输入信号为零，查看回油口的流量情况。如何测试：　对于舵机来说，要分别在三个位置观察泄露情况。　驱动舵机活塞在中位，保持1分钟，泄露量不应大于984cc/min（参考数据）　驱动舵机活塞在全伸位，保持1分钟，泄露量不应大于984cc/min（参考数据）　驱动舵机活塞在全缩位，保持1分钟，泄露量不应大于984cc/min（参考数据）控制流量、空载流量曲线、名义流量曲线 CONTROL FLOW，FLOW CURVE，NORMAL FLOW CURVE控制流量定义：　从伺服阀的控制油口A或B流出的流量。负载压降为零时的控制流量为空载流量，负载压降部位零时的控制流量称为负载流量。空载流量曲线定义　空载控制流量随输入电流在正负额定电流之间做出的一个完整循环的连续曲线。名义流量曲线　空载流量曲线中点的轨迹解释补充：　事实上，他并不是一条直线，而是如下图，存在1.无效区2.正常流量区域3.饱和区域，需要说明的是上图，由于空载流量线性度比较好，会很容易误导名义流量曲线是直线，当然，如果空载流量线性度确实很完美，那名义流量曲线就会是接近直线。为啥要反复强调这个问题，是不想让你和名义流量增益曲线搞混，继续往下看。流量增益、名义流量增益 FLOW GAIN，NORMAL FLOW GAIN流量增益定义：　流量曲线的斜率。解释：　单位输入伺服阀电流的变化量，施加到伺服阀后，伺服阀所对应的输出流量的变化量，它是在负载压力为零的情况下测得的。伺服阀的流量增益，直接影响着伺服系统中的开环放大系数。　几何图像表示为空载流量曲线的各点的切线，下图中的黄色切线。名义流量增益定义：　从名义流量曲线的零流量向两极性方向各作一条与名义流量曲线偏差最小的直线，为名义流量增益线解释：　图中黄色和蓝色的的直线，注意：并不是一条直线。线性度 LINEARITY线性度定义：　名义流量曲线的直线性，用名义流量曲线与名义流量增益的最大偏差来衡量，并以额定电流的百分比表示。解释：　见下图几何表达，△i除以额定电流的百分比就是线性度。对称度 SYMMETRY对称度定义：　两个极性的名义流量增益一直的程度，用二者之差对较大者的百分比表示。解释：　见下图几何表达，SYMMETRY的计算方法，其中S为名义流量增益线的斜率。滞环 Hysteresis滞环的定义：　在正负额定电流之间，以小于测试设备动态特性起作用的速度循环，对于产生相同输出的往与返的输入电流之差的最大值以其与额定电流的百分比表示。解释：　几何图像表达，会更直观一些。遮盖 LAP遮盖的定义：　滑阀位于零位时，固定节流棱边与可动节流棱边轴向位置的相对关系。解释：　几何图像表达，下图描述了阀芯和阀体之间的配合关系以及影响流量变化趋势的情况。注意区分清楚，正遮盖，零遮盖和负遮盖。瞬态响应（阶跃响应） Transient response阶跃响应的定义：　阶跃信号输入时，输出的跟踪特性。解释：　当我们给伺服阀输入一个阶跃信号后，快速记录伺服阀的输出流量对阶跃输入信号的跟踪过程，以时间域的曲线标识出来，这就是伺服阀的瞬态响应。主要研究的是伺服阀的快速性。主要指标：最大超调量：上升时间：　首次从零到达稳态的时间，如果没有超调的系统而言，从稳态的10%上升到稳态的90%所需要的时间。峰值时间：过渡过程时间振荡次数：　响应曲线穿越稳态值次数的一半计算，下图的振荡次数为1频率响应 FREQUENCY RESPONSE频率响应的定义：　当横幅正弦输入信号在规定的频率范围内变化时，控制流量对输入电流的复数比。 解释： 　首先我们需要复习一下三角函数：　频率特性包括了幅频特性和相频特性，其中，幅频特性用幅频比表示幅频比 AMPLITUDE RATIO幅频比定义：　通常用输出流量幅值Ai与同一输入电流幅值下指定基准低频时（5或者10Hz）的输出流量幅值A0之比随输入电流频率变化的曲线表示。表示：dB = 20 log10(Ai/A0).　通常以幅值瞬间到 3dB时的频率为幅频宽，为啥是 3dB?　因为 3dB所对应的幅值比为0.707，也就是说，此时的幅值已经衰减到了70%，在弱的话，输出信号的就太弱了，算是个判定标准。　说明，以上的是《液压伺服与比例控制》书中的解释，但视频教程给的是输出流量和输入信号幅值的比值。我查阅了英文资料：　初步认为书中的描述更准确一些，还需要进一步确认落实。相频特性 PHASE LAG相频特性的定义：　相频特性是输出流量与输入电流的相位差随输入电流频率变化的曲线，以度标识　下图的φ就是相频特性落后的几何表达，相频为啥要定义90°？　这表示输出信号比输入信号落后了90°，这是一个及格线，要是再慢，就不合格了。伯德图 BODE DIAGRAM　伯德图可以清晰的表示清楚幅频和相频曲线，上部分是幅频特性曲线，下部分为相频特性曲线，其中0.5表示输入信号为额定输入电流信号的0.5%时的幅频相频特性曲线。50表示表示输入信号为额定输入电流信号的50%时的幅频相频特性曲线。幅频和相频意义 - 隐藏 - 参考文档：SAE ARP490F 2008 Electrohydraulic Servovalves 《液压伺服与比例控制》 宋锦文 陈建文C.LiVEE | 电液伺服阀特性参数解读 王鑫