作文：爱的手臂范文

第一篇：作文：爱的手臂范文

爱的手臂

新辉教育-----邓慧

黄昏，天空的晚霞美丽极了。我站在窗前，望着田野里那一片蒲公英草地，每一颗幼小的蒲公英旁都有一颗成年的蒲公英挺直着身板。

妈妈说，蒲公英只有在黄昏时才绽放，所以他们很少“见面”，我突然觉得我就像蒲公英一样，总见不着爸爸妈妈。通常，我总是一个人在家，玩弄着各种东西，把房间里显得有点老旧地抽屉拉进拉出。那时候真的很无聊，小小地我什么都做不了，也不爱和邻居家的妹妹玩耍，所以常常都靠看电视来打发时间，看得烦了，便趴在窗前，望向楼下，盼着爸妈，但总是落空，幼时的我------孤单

慢慢地，我开始变得外向了，妈妈也总是说我越来越像个假小子了，跟小时候一点都不相同，我不吭声，只是默默地做着自己地事情，但平时仍看不见爸妈，我却不在乎，脑子里只想着玩耍，学习也不怎么努力，也更不管爸妈把我臭骂了多少次，然而我还是改不了这习性。

少时地我------贪玩

现在，我渐渐地长大了，从女孩子变成了女生，然而贪玩却一点儿也没有减少，反倒多了几分叛逆，老爱和爸妈吵架，觉得他们不可理喻，一吵起来就没完没了，爸爸也没有办法，只能做一个旁观者。

夜晚，客厅地灯亮着，妈妈坐在沙发上，手里拿着一本泛黄地相册，在慢慢地翻阅。是啊，我们家好久都没有照全家福了，妈妈的泪落在了一张相片上。我仔细地看着妈妈，她地头上多了几丝白发，脸上也增添了几根皱纹，她那长满老茧地手因哭泣而颤抖，我站在角落地一旁，努力控制着自己，不让泪水从眼眶里涌出来。我走了过去，轻轻地叫了一声：“妈。”她抬起头直直地看着我，此时她地泪水再次夺眶而出。我坐在她地身边，替她擦泪并说道：“瞧你，多大了还哭。”她笑了，那种笑，让我觉得温暖、觉得亲切，还伴随着一丝地心痛„„

现在的我------懂事

爸妈，在你们精心地教育下，深深地鼓励下，我懂得了什么是母爱。爸妈不管我在哪里，你们爱的手臂永远在我地头上，为我撑起一片天空。

第二篇：小学作文：张开手臂,拥抱世界

张开手臂，拥抱世界

阳光总是那么幸福，真想张开手臂把它拥入怀中。妈妈说，那样就等于拥抱了世界。

我并不是一个孤独的孩子。所有人都这么说。是的，我学习好，人缘好。但是我总觉得缺点什么。眼睫毛轻坠，陷入了回忆。

小时候，我应该算幸福吧？受了委屈但至少不会像卖火柴的女孩一样，被冻死街头。

幼儿园的女孩子说：你长得难看，我们不和你玩。我的天哪，什么叫“我长得难看”？难道一定要有飘逸的长发、可爱的裙子才算好看吗？是的，虽然我的名字被你们从“陈悦虹”丑化为“陈若虹”，后来又被你们彻底“进化”为“陈热狗”，但是我都没有怪你们哪。那个我一生都记得的幼儿园老师又说：就会骗人，坏孩子！即使我是坏孩子，但是你也好不到哪里去啊？还不是为人师表说脏话？何况我还是纯洁的好孩子。……

我记忆里，小时候在学校都没好气受的，叛逆心理就是从那个时候开始滋生的吧？或许那时候我一点都没有在意，想都不会想？用现在的眼光看，小时候的我不怎么会抱怨，反而是一直被人欺负。不过，小时候没有个人思想，也只能等到回家扑入妈妈怀里。上小学时，该算生活有了新的转折点吧？至少从那个时候开始我受到了老师、长辈的称赞。

我很爱虚名，看到别人当我曾做过的职位，且做得更好，虽然不会嫉妒，但心里还是会不舒服。有一个大胆的同学以我的名义去向老

师说：老师，她说她也要做那个职位。当时真是丢脸死了！不过那个同学真的道出了我的心思，我想做，但是碍于面子，又不敢。想而不敢，真难受啊。

那时候的孩子好纯洁，他们不像幼儿园的孩子，个个高贵，他们只是普通的农村孩子。虽然我长得是不怎么样，但他们却给了我久违渴望已久的友谊。【因为以前没有，所以“久违”谈不上】

那时候没珍惜，没多想。现在长大了，回头看突然觉得那些朋友好善良！但我却不懂得珍惜，或许有一天当年的纯真也会消失不见。现在我应该算是长大了吧？纯真的眼光可以透视到，我的思想开始变得千丝万缕，眼睛被事物的蒙雾挡住了，看东西都变得复杂。我会为一个朋友担心上好几天，会为我们“简单”的友谊担忧许久；我会为小小的事沉思上好久；我会为某件不干自己的事设好复杂的台词等着别人来伤害……总之，我像是变成一个近视眼，走入深谷被刺得千疮百孔。【一切只是浮云遮望眼】

我不止一次努力往上爬，力气从未用尽。我想，拥有幸福怕是不容易了??温暖的阳光很难得；纯真的话语很少见；简单的眼光似乎永不属于我……

温暖、纯真、简单……这是什么？我突然灵光一闪。我懂了。温暖的心、纯真的情、简单的眼光??这就是拥抱世界的手臂，拥抱世界，就等于拥有了幸福。

第三篇：机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-手臂练习技巧

大部分人都是成年以后才接触拉丁舞，并且大多数人没有什么舞蹈基础，如何呈现出漂亮、协调的手臂姿势，是学习拉丁舞一段时间后，腰腿脚基本功过关、熟练掌握一两个套路后，应注意解决的问题。

注意观察手臂动作不协调的朋友们，就会发现他们的后背没有力量的延伸，侧腰和腹肌也没有恰当的压缩和延伸。

要背部有良好的延伸，有几个动作，可以起到一些锻炼手臂和胸腰协调性的作用。可以放一首节奏明确热烈的歌曲作为背景音乐。

1、双脚与肩同宽，双手叉胯，胸部向前左后右四个方位延伸。注意，此时胯部和腿不随胸部的运动而动，放松头、脖和肩，并在固定位置保持静止。连续做三个八拍，然后速度加快一倍，胸部绕圈一个八拍，八圈。反向做四个八拍。

说明：这个动作锻炼中腰及背部的协调性，注意其他部位不要随胸部的运动而动，胸部运动的幅度要尽可能加大。

2、站姿与前相同，放松肩部，手臂和胸部运动，其他部位静止。胸到左后方，然后直接到达右前方。在胸部向左后方运动时，小臂和手腕带动手臂向相反延伸，当胸部到达左后方时，手臂到达最右前方。胸部向右前运动时，小臂和手腕带动手臂向左后方向运动，当胸部到达最右前时，手臂在最左后方。两拍一个往复。反方向同样。

说明：此动作过程中，手心向下，手腕和小臂灌注满力量，带动手指和大臂。此动作可以增加胸腰的灵活性，以及和手臂的配合，手臂该如何用力，能增强弓二头肌和胸肌的力量控制。一定要注意肩部下沉，不随手臂和胸部的运动而动。

这两个动作在多次反复练习，尽量优美一些，并有恰当的力量，就会使手臂对力量的大小有了肌肉记忆，这个力量贯穿的程度可以当作拉丁舞中手臂的力量的最基础训练。

关键处(1)：肩膀带动

拉丁舞里面肩膀是一个很关键的部位，你的手势漂不漂亮，很关键的一点就在于如何运用肩膀。拉丁舞手势摆动不只是大臂带动小臂的运动，而是用肩膀带动的。怎样带动，这需要很深的理解和坚持的练习，前期练习肩膀会很痛很酸，习惯后觉得抬动肩膀是多么容易的事情。要注意的问题是抬动肩膀，不是让你把肩膀往上耸，那是错误的。

关键处(2)：手臂摆动

手臂肉多？想减没问题！关键在你怎么动。你随便甩甩是根本没用的,美之璇。拉丁舞是全身躯干运动，跳舞的时候要收缩全身的肌肉。可能减不下去吗？拉丁舞的手，坚韧有力，速度迅猛。不是随便甩两下就能有的力度。所以靠肩膀带动是一部分，另外一部分就是靠长期训练让自己的手臂变的更加有力和修长。练习时一定要注意手臂要伸直，除了部分特定弯曲动作外。比如恰恰的纽约步等，就需要强力快速甩出去。注意的地方在手指，一定要跟随速度摆好姿势，灵活运用手腕。

第五篇：描写手臂动作的词语

手疾眼快

【解释】疾：迅速。动作迅速，眼光敏捷。形容机灵敏捷。

【出处】明吴承恩《西游记》第四回：原来悟空手疾眼快，正在那混乱之时，赶在哪吒脑后，着左膊上一棒打来。

指手划脚

【解释】用手指，用脚划。形容说话时用手脚示意，也比喻瞎指挥，乱加指点批评。

【出处】明冯梦龙《醒世恒言》：问起根由，毛泼皮指手划脚，剖说那事。

摩拳擦掌

【解释】形容战斗或劳动之前，人们精神振奋，跃跃欲试的样子。

【出处】元康进之《李逵负荆》第二折：俺可也摩拳擦掌，行行里按不住莽撞心头气。

手舞足蹈

【解释】蹈：顿足踏地。两手舞动，两只脚也跳了起来。形容高兴到了极点。也手乱舞、脚乱跳的狂态。

【出处】《诗经周南关雎序》：永(咏)歌之不足，不知手之舞之，足之蹈之也。

手忙脚乱

【解释】形容遇事慌张，不知如何是好。

【出处】宋释普济《五灯会元》：问：‘如何是大悲境?’师曰：‘千眼都来一只收。’曰：‘如何是境中人?’师曰：‘手忙脚乱。’

匍匐前进

【解释】身体贴近地面以手臂和腿的力量推动身体前进的运动方法。

【拓展】通常有受敌火威胁,遮蔽物较低的场合采用。

蹑手蹑脚

【解释】形容放轻脚步走的样子。也形容偷偷摸摸、鬼鬼祟祟的样子。

【出处】清曹雪芹《红楼梦》第五十四回：于是大家蹑手蹑脚，潜踪进镜壁去一看。

张牙舞爪

【解释】张：张开;舞：挥舞。形容猛兽凶恶可怕。也比喻猖狂凶恶。

【出处】《敦煌变文集孔子项托相问书》附录二《新编小儿难孔子》：鱼生三日游于江湖，龙生三日张牙舞爪。

抓耳挠腮

【解释】挠：搔。抓抓耳朵，搔搔肋帮子。形容心里焦急而无法可想的样子。

【出处】明凌濛初《二刻拍案惊奇》卷十一：大郎听罢，气得抓耳挠腮，没有是处。