第一篇：作文：愛的手臂范文

愛的手臂

新輝教育-----鄧慧

黃昏，天空的晚霞美麗極了。我站在窗前，望著田野里那一片蒲公英草地，每一顆幼小的蒲公英旁都有一顆成年的蒲公英挺直著身板。

媽媽說，蒲公英只有在黃昏時才綻放，所以他們很少“見面”，我突然覺得我就像蒲公英一樣，總見不著爸爸媽媽。通常，我總是一個人在家，玩弄著各種東西，把房間里顯得有點老舊地抽屜拉進拉出。那時候真的很無聊，小小地我什么都做不了，也不愛和鄰居家的妹妹玩耍，所以常常都靠看電視來打發(fā)時間，看得煩了，便趴在窗前，望向樓下，盼著爸媽，但總是落空，幼時的我------孤單

慢慢地，我開始變得外向了，媽媽也總是說我越來越像個假小子了，跟小時候一點都不相同，我不吭聲，只是默默地做著自己地事情，但平時仍看不見爸媽，我卻不在乎，腦子里只想著玩耍，學(xué)習(xí)也不怎么努力，也更不管爸媽把我臭罵了多少次，然而我還是改不了這習(xí)性。

少時地我------貪玩

現(xiàn)在，我漸漸地長大了，從女孩子變成了女生，然而貪玩卻一點兒也沒有減少，反倒多了幾分叛逆，老愛和爸媽吵架，覺得他們不可理喻，一吵起來就沒完沒了，爸爸也沒有辦法，只能做一個旁觀者。

夜晚，客廳地燈亮著，媽媽坐在沙發(fā)上，手里拿著一本泛黃地相冊，在慢慢地翻閱。是啊，我們家好久都沒有照全家福了，媽媽的淚落在了一張相片上。我仔細地看著媽媽，她地頭上多了幾絲白發(fā)，臉上也增添了幾根皺紋，她那長滿老繭地手因哭泣而顫抖，我站在角落地一旁，努力控制著自己，不讓淚水從眼眶里涌出來。我走了過去，輕輕地叫了一聲：“媽。”她抬起頭直直地看著我，此時她地淚水再次奪眶而出。我坐在她地身邊，替她擦淚并說道：“瞧你，多大了還哭。”她笑了，那種笑，讓我覺得溫暖、覺得親切，還伴隨著一絲地心痛??

現(xiàn)在的我------懂事

爸媽，在你們精心地教育下，深深地鼓勵下，我懂得了什么是母愛。爸媽不管我在哪里，你們愛的手臂永遠在我地頭上，為我撐起一片天空。

第二篇：小學(xué)作文：張開手臂,擁抱世界

張開手臂，擁抱世界

陽光總是那么幸福，真想張開手臂把它擁入懷中。媽媽說，那樣就等于擁抱了世界。

我并不是一個孤獨的孩子。所有人都這么說。是的，我學(xué)習(xí)好，人緣好。但是我總覺得缺點什么。眼睫毛輕墜，陷入了回憶。

小時候，我應(yīng)該算幸福吧？受了委屈但至少不會像賣火柴的女孩一樣，被凍死街頭。

幼兒園的女孩子說：你長得難看，我們不和你玩。我的天哪，什么叫“我長得難看”？難道一定要有飄逸的長發(fā)、可愛的裙子才算好看嗎？是的，雖然我的名字被你們從“陳悅虹”丑化為“陳若虹”，后來又被你們徹底“進化”為“陳熱狗”，但是我都沒有怪你們哪。那個我一生都記得的幼兒園老師又說：就會騙人，壞孩子！即使我是壞孩子，但是你也好不到哪里去啊？還不是為人師表說臟話？何況我還是純潔的好孩子。……

我記憶里，小時候在學(xué)校都沒好氣受的，叛逆心理就是從那個時候開始滋生的吧？或許那時候我一點都沒有在意，想都不會想？用現(xiàn)在的眼光看，小時候的我不怎么會抱怨，反而是一直被人欺負。不過，小時候沒有個人思想，也只能等到回家撲入媽媽懷里。上小學(xué)時，該算生活有了新的轉(zhuǎn)折點吧？至少從那個時候開始我受到了老師、長輩的稱贊。

我很愛虛名，看到別人當我曾做過的職位，且做得更好，雖然不會嫉妒，但心里還是會不舒服。有一個大膽的同學(xué)以我的名義去向老

師說：老師，她說她也要做那個職位。當時真是丟臉死了！不過那個同學(xué)真的道出了我的心思，我想做，但是礙于面子，又不敢。想而不敢，真難受啊。

那時候的孩子好純潔，他們不像幼兒園的孩子，個個高貴，他們只是普通的農(nóng)村孩子。雖然我長得是不怎么樣，但他們卻給了我久違渴望已久的友誼。【因為以前沒有，所以“久違”談不上】

那時候沒珍惜，沒多想。現(xiàn)在長大了，回頭看突然覺得那些朋友好善良！但我卻不懂得珍惜，或許有一天當年的純真也會消失不見。現(xiàn)在我應(yīng)該算是長大了吧？純真的眼光可以透視到，我的思想開始變得千絲萬縷，眼睛被事物的蒙霧擋住了，看東西都變得復(fù)雜。我會為一個朋友擔心上好幾天，會為我們“簡單”的友誼擔憂許久；我會為小小的事沉思上好久；我會為某件不干自己的事設(shè)好復(fù)雜的臺詞等著別人來傷害……總之，我像是變成一個近視眼，走入深谷被刺得千瘡百孔。【一切只是浮云遮望眼】

我不止一次努力往上爬，力氣從未用盡。我想，擁有幸福怕是不容易了??溫暖的陽光很難得；純真的話語很少見；簡單的眼光似乎永不屬于我……

溫暖、純真、簡單……這是什么？我突然靈光一閃。我懂了。溫暖的心、純真的情、簡單的眼光??這就是擁抱世界的手臂，擁抱世界，就等于擁有了幸福。

第三篇：機器人手臂教程英文版

Degrees of Freedom Robot Workspace Mobile Manipulators Force Calculations Forward Kinematics Inverse Kinematics Motion Planning Velocity

Sensing

End Effector Design

About this Robot Arm Tutorial

The robot arm is probably the most mathematically complex robot you could ever build.As such, this tutorial can't tell you everything you need to know.Instead, I will cut to the chase and talk about the bare minimum you need to know to build an effective robot arm.Enjoy!To get you started, here is a video of a robot arm assignment I had when I took Robotic Manipulation back in college.My group programmed it to type the current time into the keyboard...(lesson learned, don't crash robot arms into your keyboard at full speed while testing in front of your professor)You might be also interested in a robot arm I built that can shuffle, cut, and deal playing cards.Degrees of Freedom(DOF)

The degrees of freedom, or DOF, is a very important term to understand.Each degree of freedom is a joint on the arm, a place where it can bend or rotate or translate.You can typically identify the number of degrees of freedom by the number of actuators on the robot arm.Now this is very importantL1^2x * L2 * s2)/(x^2 + y^2))where c2 =(x^2 + y^2L2^2)/(2 * L1 * L2);and s2 = sqrt(1leaving the end effector to possibly swing wildly between those points.In the image below the end effector of the robot arm is moving from the blue point to the red point.In the top example, the end effector travels a straight line.This is the only possible motion this arm can perform to travel a straight line.In the bottom example, the arm is told to get to the red point as fast as possible.Given many different trajectories, the arm goes the method that allows the joints to rotate the fastest.Which method is better? There are many deciding factors.Usually you want straight lines when the object the arm moves is really heavy, as it requires the momentum change for movement(momentum = mass * velocity).But for maximum speed(perhaps the arm isn't carrying anything, or just light objects)you would want maximum joint speeds.Now suppose you want your robot arm to operate at a certain rotational velocity, how much torque would a joint need? First, lets go back to our FBD:

Now lets suppose you want joint J0 to rotate 180 degrees in under 2 seconds, what torque does the J0 motor need? Well, J0 is not affected by gravity, so all we need to consider is momentum and inertia.Putting this in equation form we get this: torque = moment_of_inertia * angular_acceleration breaking that equation into sub components we get: torque =(mass * distance^2)*(change_in_angular_velocity / change_in_time)and change_in_angular_velocity =(angular_velocity1)-(angular_velocity0)

angular_velocity = change_in_angle / change_in_time

Now assuming at start time 0 that angular_velocity0 is zero, we get torque =(mass * distance^2)*(angular_velocity / change_in_time)where distance is defined as the distance from the rotation axis to the center of mass of the arm: center of mass of the arm = distance = 1/2 *(arm_length)(use arm mass)but you also need to account for the object your arm holds: center of mass of the object = distance = arm_length(use object mass)So then calculate torque for both the arm and then again for the object, then add the two torques together for the total: torque(of_object)+ torque(of_arm)= torque(for_motor)

And of course, if J0 was additionally affected by gravity, add the torque required to lift the arm to the torque required to reach the velocity you need.To avoid doing this by hand, just use the robot arm calculator.But it gets harder...the above equation is for rotational motion and not for straight line motions.Look up something called a Jacobian if you enjoy mathematical pain =P Another Video!

In order to better understand robot arm dynamics, we had a robot arm bowling competition using the same DENSO 6DOF robot arms as in the clocks video.Each team programs an arm to do two tasks: o o Try to place all three of its pegs in the opponents' goal Block opponent pegs from going in your own goal Enjoy!(notice the different arm trajectories)Arm Sagging

Arm sagging is a common affliction of badly designed robot arms.This is when an arm is too long and heavy, bending when outwardly stretched.When designing your arm, make sure the arm is reinforced and lightweight.Do a finite element analysis to determine bending deflection/stress such as I did on my ERP robot: Keep the heaviest components, such as motors, as close to the robot arm base as possible.It might be a good idea for the middle arm joint to be chain/belt driven by a motor located at the base(to keep the heavy motor on the base and off the arm).The sagging problem is even worse when the arm wobbles between stop-start motions.The solve this, implement a PID controller so as to slow the arm down before it makes a full stop.Sensing

Most robot arms only have internal sensors, such asencoders.But for good reasons you may want to add additional sensors, such as video, touch, haptic, etc.A robot arm without video sensing is like an artist painting with his eyes closed.Using basic visual feedback algorithms, a robot arm could go from point to point on its own without a list of preprogrammed positions.Giving the arm a red ball, it could actually reach for it(visual tracking and servoing).If the arm can locate a position in X-Y space of an image, it could then direct the end effector to go to that same X-Y location(by using inverse kinematics).If you are interested in learning more about the vision aspect of visual servoing, please read the Computer Vision Tutorials for more information.Haptic sensing is a little different in that there is a human in the loop.The human controls the robot arm movements remotely.This could be done by wearing a special glove, or by operating a miniature model with position sensors.Robotic arms for amputees are doing a form of haptic sensing.Also to note, some robot arms have feed back sensors(such as touch)that gets directed back to the human(vibrating the glove, locking model joints, etc.).Tactile sensing(sensing by touch)usually involves force feedback sensors and current sensors.These sensors detect collisions by detecting unexpected force/current spikes, meaning a collision has occurred.A robot end effector can detect a successful grasp, and not grasp too tight or too lightly, just by measuring force.Another method would be to use current limitersperhaps even identify the object by its weight.Try this.Close your eyes, and put both of your hands in your lap.Now keeping your eyes closed, move your hand slowly to reach for your computer mouse.Do it！！You will see why soon...Now what will happen is that your hand will partially miss, but at least one of your fingers will touch the mouse.After that finger touches, your hand will suddenly re-adjust its position because it now knows exactly where that mouse is.This is the benefit of tactile sensing-no precision encoders required for perfect contact!

End Effector Design

In the future I will write a separate tutorial on how to design robot grippers, as it will require many more pages of material.In the meantime, you might be interested in reading the tutorial for calculating friction and force for robot end effectors.I also went in to some detail describing my robot arm card dealing gripper.Anyway, I hope you have enjoyed this robot arm tutorial!

第四篇：拉丁舞基本功-手臂練習(xí)技巧

大部分人都是成年以后才接觸拉丁舞，并且大多數(shù)人沒有什么舞蹈基礎(chǔ)，如何呈現(xiàn)出漂亮、協(xié)調(diào)的手臂姿勢，是學(xué)習(xí)拉丁舞一段時間后，腰腿腳基本功過關(guān)、熟練掌握一兩個套路后，應(yīng)注意解決的問題。

注意觀察手臂動作不協(xié)調(diào)的朋友們，就會發(fā)現(xiàn)他們的后背沒有力量的延伸，側(cè)腰和腹肌也沒有恰當?shù)膲嚎s和延伸。

要背部有良好的延伸，有幾個動作，可以起到一些鍛煉手臂和胸腰協(xié)調(diào)性的作用。可以放一首節(jié)奏明確熱烈的歌曲作為背景音樂。

1、雙腳與肩同寬，雙手叉胯，胸部向前左后右四個方位延伸。注意，此時胯部和腿不隨胸部的運動而動，放松頭、脖和肩，并在固定位置保持靜止。連續(xù)做三個八拍，然后速度加快一倍，胸部繞圈一個八拍，八圈。反向做四個八拍。

說明：這個動作鍛煉中腰及背部的協(xié)調(diào)性，注意其他部位不要隨胸部的運動而動，胸部運動的幅度要盡可能加大。

2、站姿與前相同，放松肩部，手臂和胸部運動，其他部位靜止。胸到左后方，然后直接到達右前方。在胸部向左后方運動時，小臂和手腕帶動手臂向相反延伸，當胸部到達左后方時，手臂到達最右前方。胸部向右前運動時，小臂和手腕帶動手臂向左后方向運動，當胸部到達最右前時，手臂在最左后方。兩拍一個往復(fù)。反方向同樣。

說明：此動作過程中，手心向下，手腕和小臂灌注滿力量，帶動手指和大臂。此動作可以增加胸腰的靈活性，以及和手臂的配合，手臂該如何用力，能增強弓二頭肌和胸肌的力量控制。一定要注意肩部下沉，不隨手臂和胸部的運動而動。

這兩個動作在多次反復(fù)練習(xí)，盡量優(yōu)美一些，并有恰當?shù)牧α浚蜁故直蹖αα康拇笮∮辛思∪庥洃洠@個力量貫穿的程度可以當作拉丁舞中手臂的力量的最基礎(chǔ)訓(xùn)練。

關(guān)鍵處(1)：肩膀帶動

拉丁舞里面肩膀是一個很關(guān)鍵的部位，你的手勢漂不漂亮，很關(guān)鍵的一點就在于如何運用肩膀。拉丁舞手勢擺動不只是大臂帶動小臂的運動，而是用肩膀帶動的。怎樣帶動，這需要很深的理解和堅持的練習(xí)，前期練習(xí)肩膀會很痛很酸，習(xí)慣后覺得抬動肩膀是多么容易的事情。要注意的問題是抬動肩膀，不是讓你把肩膀往上聳，那是錯誤的。

關(guān)鍵處(2)：手臂擺動

手臂肉多？想減沒問題！關(guān)鍵在你怎么動。你隨便甩甩是根本沒用的,美之璇。拉丁舞是全身軀干運動，跳舞的時候要收縮全身的肌肉。可能減不下去嗎？拉丁舞的手，堅韌有力，速度迅猛。不是隨便甩兩下就能有的力度。所以靠肩膀帶動是一部分，另外一部分就是靠長期訓(xùn)練讓自己的手臂變的更加有力和修長。練習(xí)時一定要注意手臂要伸直，除了部分特定彎曲動作外。比如恰恰的紐約步等，就需要強力快速甩出去。注意的地方在手指，一定要跟隨速度擺好姿勢，靈活運用手腕。

第五篇：描寫手臂動作的詞語

手疾眼快

【解釋】疾：迅速。動作迅速，眼光敏捷。形容機靈敏捷。

【出處】明吳承恩《西游記》第四回：原來悟空手疾眼快，正在那混亂之時，趕在哪吒腦后，著左膊上一棒打來。

指手劃腳

【解釋】用手指，用腳劃。形容說話時用手腳示意，也比喻瞎指揮，亂加指點批評。

【出處】明馮夢龍《醒世恒言》：問起根由，毛潑皮指手劃腳，剖說那事。

摩拳擦掌

【解釋】形容戰(zhàn)斗或勞動之前，人們精神振奮，躍躍欲試的樣子。

【出處】元康進之《李逵負荊》第二折：俺可也摩拳擦掌，行行里按不住莽撞心頭氣。

手舞足蹈

【解釋】蹈：頓足踏地。兩手舞動，兩只腳也跳了起來。形容高興到了極點。也手亂舞、腳亂跳的狂態(tài)。

【出處】《詩經(jīng)周南關(guān)雎序》：永(詠)歌之不足，不知手之舞之，足之蹈之也。

手忙腳亂

【解釋】形容遇事慌張，不知如何是好。

【出處】宋釋普濟《五燈會元》：問：‘如何是大悲境?’師曰：‘千眼都來一只收。’曰：‘如何是境中人?’師曰：‘手忙腳亂。’

匍匐前進

【解釋】身體貼近地面以手臂和腿的力量推動身體前進的運動方法。

【拓展】通常有受敵火威脅,遮蔽物較低的場合采用。

躡手躡腳

【解釋】形容放輕腳步走的樣子。也形容偷偷摸摸、鬼鬼祟祟的樣子。

【出處】清曹雪芹《紅樓夢》第五十四回：于是大家躡手躡腳，潛蹤進鏡壁去一看。

張牙舞爪

【解釋】張：張開;舞：揮舞。形容猛獸兇惡可怕。也比喻猖狂兇惡。

【出處】《敦煌變文集孔子項托相問書》附錄二《新編小兒難孔子》：魚生三日游于江湖，龍生三日張牙舞爪。

抓耳撓腮

【解釋】撓：搔。抓抓耳朵，搔搔肋幫子。形容心里焦急而無法可想的樣子。

【出處】明凌濛初《二刻拍案驚奇》卷十一：大郎聽罷，氣得抓耳撓腮，沒有是處。