电大机电一体化系统设计基础（小抄参考）.doc

试卷代号：1118 中央广播电视大学20092010学年度第二学期“开放本科”期末考试 机电一体化系统设计基础 试题 2010年7月 一、判断题(正确的打，错误的打X，每题3分，共30分) 1机电一体化系统的主要功能就是对输入的物质按照要求进行处理，输出具有所需特性的物质。(X ) 2滚珠丝杠垂直传动时，必须在系统中附加自锁或制动装置。( ) 3齿轮传动的啮合间隙会造成一定的传动死区，若在闭环系统中，传动死区会使系统产生低频震荡。( ) 4迟滞是传感器的一种动态误差，是由于在传感器的正反行程中的输出输入特性曲线不重合引起的。( X ) 5直流伺服电动机和永磁同步交流伺服电动机都可以采用PWM控制方式进行控制( ) 6，无论采用何种控制方案，系统的控制精度总是高于检测装置的精度。( X ) 7计算机控制系统的采样周期越小，其控制精度就越高。( X ) 8仿真根据采用的模型可以分为计算机仿真、半物理仿真和全物理仿真。( ) 9现代嵌入式系统的设计方法是将系统划分为硬件和软件两个独立的部分，然后按各自 的设计流程分别完成。( X )10数字化物理样机就是一种结构设计软件，强调结构上的设计。(X )二、单选题(每小题4分，共24分) 1传动系统的固有频率对传动精度有影响，固有频率可减小系统地传动误差， 系统刚度可提高固有频率。( A ) A提高，提高 B提高，减小 C. 减小，提高 D减小，减小 2下列哪个不是传感器的动特性?( D ) A. 幅频特性 B临界频率 C. .相频特性 D. 分辨率 3对同一种步进电机，三相单三拍的步距角是三相六拍的( C )倍。 A05 B1 C2 D3 4在开环控制系统中，常用( B )做驱动元件。 A. 直流伺服电动机 B步进电动机 C同步交流伺服电动机 D异步交流伺服电动机 5以下抑制电磁干扰的措施，除了( D )，其余都是从切断传播途径人手。 A屏蔽 B隔离 C. 滤波 D软件抗干扰 6HRGPlA喷漆机器人中的活塞式液压缸属于系统中的( C )。 A. 能源部分 B测试传感部分 C驱动部分 D执行机构三、简答题(每小题8分，共24分) 1滚珠丝杠副消除轴向间隙的调整预紧方法有哪些?圆柱直齿轮的齿侧间隙的调整方 法有哪些?答：(1)滚珠丝杠副消除轴向间隙的调整预紧方法有：螺纹预紧调整式、双螺母齿差预 紧调整式、双螺母垫片预紧调整式、弹簧式自动调整预紧式、单螺母变位导程自预紧式。 (2)圆柱直齿轮的齿侧间隙的调整方法有：偏心套调整法、轴向垫片调整法、双片薄齿轮错 齿调整法(周向拉簧式、可调拉簧式)。 2PID控制算法中比例、积分、微分部分各起何作用?答：P(比例)I(积分)D(微分)调节器是将偏差的比例、积分、微分通过线性组合构成控 制量。其中比例调节起纠正偏差的作用，且其反应迅速；积分调节能消除静差，改善系统静态 特性；微分调节有利于减少超调，加快系统的过渡过程。此三作用配合得当，可使调节过程快 速、平稳、准确，收到较好的效果。 3简述概念设计的设计过程。答：设计过程：设计任务抽象化，确定系统的总功能一将总功能分解为子功能，直到功 能元+寻找子功能(功能元)的解一将原理解进行组合，形成多种原理解设计方案+对众多方 案进行评价决策，选定最佳方案一概念产品。 四、计算题(8分) 五、综合题(14分) 根据图示气体压力传感器的原理图，分析传感检测系统的组成及各部分的作用。 四、计算题(8分) 解：由系统可知：则系统可能的最大误差为：五、综合题(14分) 答：气体压力传感器的工作原理是膜盒2的下半部与壳体1固接，上半部通过连杆与磁心 4相连，磁心4置于两个电感线圈3中，后者接人转换电路5。气体压力传感器由敏感元件、转 换元件和基本转换电路三部分组成： (1)敏感元件。膜盒2就是敏感元件，其外部与大气压P。相通，内部感受被测压力p，当p 变化时，引起膜盒上半部移动，即输出相应的位移量。 (2)转换元件。可变电感3是转化元件，它把输入的位移量转换成电感的变化。 (3)基本转换电路。5即为转换电路"If we don't do that it will go on and go on. We have to stop it; we need the courage to do it."His comments came hours after Fifa vice-president Jeffrey Webb - also in London for the FA's celebrations - said he wanted to meet Ivory Coast international Toure to discuss his complaint.CSKA general director Roman Babaev says the matter has been "exaggerated" by the Ivorian and the British media.Blatter, 77, said: "It has been decided by the Fifa congress that it is a nonsense for racism to be dealt with with fines. You can always find money from somebody to pay them."It is a nonsense to have matches played without spectators because it is against the spirit of football and against the visiting team. It is all nonsense.待添加的隐藏文字内容2"We can do something better to fight racism and discrimination."This is one of the villains we have today in our game. But it is only with harsh sanctions that racism and discrimination can be washed out of football."The (lack of) air up there Watch mCayman Islands-based Webb, the head of Fifa's anti-racism taskforce, is in London for the Football Association's 150th anniversary celebrations and will attend City's Premier League match at Chelsea on Sunday."I am going to be at the match tomorrow and I have asked to meet Yaya Toure," he told BBC Sport."For me it's about how he felt and I would like to speak to him first to find out what his experience was."Uefa has opened disciplinary proceedings against CSKA for the "racist behaviour of their fans" during City's 2-1 win.Michel Platini, president of European football's governing body, has also ordered an immediate investigation into the referee's actions.CSKA said they were "surprised and disappointed" by Toure's complaint. In a statement the Russian side added: "We found no racist insults from fans of CSKA."Baumgartner the disappointing news: Mission aborted.The supersonic descent could happen as early as Sunda.The weather plays an important role in this mission. Starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. It will climb higher than the tip of Mount Everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. As he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.The balloon will slowly drift to the edge of space at 120,000 feet ( Then, I would assume, he will slowly step out onto something resembling an Olympic diving platform.Below, the Earth becomes the concrete bottom of a swimming pool that he wants to land on, but not too hard. Still, he'll be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end.Skydiver preps for the big jumpWhen he jumps, he is expected to reach the speed of sound - 690 mph (1,110 kph) - in less than 40 seconds. Like hitting the top of the water, he will begin to slow as he approaches the more dense air closer to Earth. But this will not be enough to stop him completely.If he goes too fast or spins out of control, he has a stabilization parachute that can be deployed to slow him down. His team hopes it's not needed. Instead, he plans to deploy his 270-square-foot (25-square-meter) main chute at an altitude of around 5,000 feet (1,524 meters).In order to deploy this chute successfully, he will have to slow to 172 mph (277 kph). He will have a reserve parachute that will open automatically if he loses consciousness at mach speeds.Even if everything goes as planned, it won't. Baumgartner still will free fall at a speed that would cause you and me to pass out, and no parachute is guaranteed to work higher than 25,000 feet (7,620 meters).cause there