专业知识库（按学科 / 专业 / 课程）
按学科门类筛选，可继续下钻到具体专业与课程；内容为各课程复习要点，用于面谈与笔试备考。
毕业论文（APS 审核稿）
核心内容
The title of my graduation paper is “Synthesis of Azaanthraquinones by Electrooxidative Cyclization of 1,6-Enynes” Azaanthraquinones are a class of natural alkaloids, the basic structure of which is 3 benzenes side by side with some of the carbon atoms replaced by nitrogen. Electrooxidative means this reaction involves the gaining and losing of electrons so that according to the faraday law, this reaction can be controlled by power source.
The reason I choose this field is that in my university, we choose tutor first and the tutor decides what we do for the graduation paper.
Now in regard of the experiment part, I first weigh the reactants and volume and put them in a three-necked flask，then I put the flask in a water bath kettle to maintain the temperature and attach the reaction system to the power source and set up the voltage，after that I let the reaction begins and leave the rest to nature.
After hours of reaction, I set up a column chromatography to separate what is left in the reaction system to get only the product, which is a long tube filled with silica gel powder.
In the reaction the reactant is 2-((2-(phenylethynyl)phenyl)amino)naphthalene-1,4-dione and can be synthesized from 1,6-enynes. Through this experiment, I successfully synthesized one azanthraquinone compound. But the yield is not satisfying, so I need to change the condition of reaction (such as electrolytes, solvents, current magnitudes and electrode materials) and find the condition giving the best yield, a bunch of potential materials were screened and multiple sets of experiments were carried out.
Through the above experiments, I established the optimal conditions，which is using tetrabutylammonium acetate as electrolyte, hexafluoroisopropyl alcohol as solvent, under open air conditions, constant current 10 mA electrolytic for two hours, and I can get the product at the yield of 85%, which is a pretty high one.
解释下题目
解释论文
实验步骤有什么
实验中遇到了什么困难
参考：来源：aps稿子.rar｜毕业论文aps审核英文稿子.docx｜专业：制药工程｜课程：毕业论文
毕设实验（APS 审核稿）
核心内容
Then, in order to investigate the substrate adaptability of this synthesis strategy,which means when I replace some of the groups of the reactants, changing the main structure, whether this method of synthesis will give me a good yield or not. I synthesized 18 azoxanthrone compounds with different substituents. The wide applicability of this synthesis strategy is proved.
To me the hardest part in this experiment is to determine the proper experimental condition, for example，what type of electrolyte should I use, how much current should be adjusted. The solution is reading more published paper in this field and learning from counterpart scientist and my tutor.
Azaanthraquinones has strong biological activity and is the active ingredient of many antibacterial and antitumor potential drugs. Therefore, this green synthesis strategy has promising applications in the field of drug synthesis
参考：来源：aps稿子.rar｜毕设实验aps可补充部分.docx｜专业：制药工程｜课程：毕设实验
CAD/CAM 计算机辅助设计与制造
核心内容
CAD/CAM（计算机辅助设计与制造）复习笔记
一、英文全称与定义
· CAD 全称 Computer Aided Design，即计算机辅助设计，指利用计算机软硬件系统辅助工程技术人员完成产品设计、绘图、分析与优化的一门技术。
· CAM 全称 Computer Aided Manufacturing，即计算机辅助制造，指利用计算机辅助完成从工艺规划到数控加工的全过程，包括刀具路径生成、数控编程与机床控制。
· CAD/CAM 即将设计与制造两个环节通过统一的数字模型连接起来，实现从产品构思、建模、仿真到加工制造的一体化。
二、发展历程
· 早期阶段：以二维绘图为主，计算机仅替代手工图板，即所谓计算机辅助绘图。
· 三维造型阶段：出现线框建模、曲面建模与实体建模，设计对象由二维图纸变为三维数字模型。
· 集成阶段：CAD 与 CAM 通过统一数据模型打通，设计结果可直接用于数控编程，形成 CAD/CAM 集成系统。
· 现代阶段：进一步与 CAE（计算机辅助工程）、PDM（产品数据管理）、CAPP（计算机辅助工艺规划）融合，向数字化设计与智能制造方向发展。
三、系统组成
· 硬件：计算机主机、图形显示器、输入设备（鼠标、键盘、数字化仪、三维扫描仪）、输出设备（绘图仪、打印机）及数控机床等。
· 软件：系统软件与支撑软件，以及二维绘图、三维建模、仿真分析、数控编程等应用软件。
· 数据库：存储零件几何信息、材料参数、工艺数据、标准件库与刀具库，是 CAD 与 CAM 之间数据传递的桥梁。
四、典型功能模块
· 二维绘图：绘制工程图、标注尺寸与公差，是早期 CAD 的核心功能。
· 三维建模：包括线框、曲面与实体建模，是后续仿真与加工的基础。
· 装配设计：将多个零件按约束关系装配，检查干涉与配合。
· 有限元仿真（CAE）：对模型施加约束与载荷，进行强度、刚度、模态、热分析等校核。
· CAM 数控编程：根据零件模型规划加工工艺，生成刀具轨迹。
· 后处理：将刀具轨迹转换为特定机床可识别的 G 代码（NC 代码）。
五、常用软件
· AutoCAD：以二维绘图见长，广泛用于工程制图。
· Creo（原 Pro/E）：参数化实体建模，建模、装配、仿真、加工一体化。
· SolidWorks：界面友好，适合中小型机械产品设计。
· UG NX：CAD/CAM/CAE 集成度高，广泛用于模具与复杂曲面加工。
· CATIA：面向汽车、航空等复杂曲面与大型装配。
· ANSYS：主流有限元分析软件，用于结构、热、流体等仿真。
六、在机械制造中的作用与优势
· 提高效率与精度：数字模型替代手工绘图，减少人为误差。
· 缩短周期：设计与制造并行，减少反复试制。
· 降低成本：减少物理样机与废品率，节约材料与工时。
· 便于修改与优化：参数化模型修改后，图纸、仿真与加工程序可同步更新。
七、面试可展开的例子
· 例子一：用 Creo 完成零件三维建模后，导入 CAE 模块或 ANSYS 施加约束与载荷，进行强度与刚度校核，根据应力云图优化结构尺寸，再返回模型修改，实现设计—仿真—优化闭环。
· 例子二：在 Creo 或 UG NX 中完成建模后进入 CAM 模块，选择毛坯、刀具与切削参数，生成刀具轨迹，经后处理输出 G 代码，传输至数控机床完成实际加工，体现 CAD/CAM 一体化流程。
参考：来源：7d2fd65f0b361d161e13ef5e7f44934f.pdf｜专业：机械工程｜课程：CAD/CAM 计算机辅助设计与制造
CAD/CAM 计算机辅助设计与制造（2）
核心内容
· 备考定位
· 场景：面试；被考几率较小；简单性准备即可，重点掌握 CAD、CAE、CAM 三个基本概念及其关系。
· CAD（Computer-aided design，计算机辅助设计）
· 又称 CADD（computer-aided design and drafting，计算机辅助设计与绘图）；指利用计算机技术进行设计及设计文档化的过程。
· Computer Aided Drafting（计算机辅助绘图）：用计算机进行绘图的过程。
· CADD 软件/环境提供输入工具，用于简化设计流程：drafting（绘图）、documentation（文档编制）、manufacturing processes（制造流程）。
· 输出形式：常为电子文件，用于打印或 machining operations（机加工）。
· 软件类型与行业相关：
· 工业类软件（建筑、制造等）通常使用 vector-based（linear）环境（基于矢量的线性环境）。
· 图形类软件使用 raster-based（pixelated）环境（基于栅格的像素化环境）。
· 定位：CAD 是 Digital Product Development（DPD，数字产品开发）的一部分，处于 Product Lifecycle Management（PLM，产品生命周期管理）流程中；与其他工具集成或独立使用：
· CAE（Computer-aided engineering，计算机辅助工程）与 FEA（Finite element analysis，有限元分析）
· CAM（Computer-aided manufacturing，计算机辅助制造），含对 CNC（Computer Numerical Control，计算机数控）机床的指令
· Photo realistic rendering（照片级真实感渲染）
· 利用 PDM（Product Data Management，产品数据管理）进行文档管理与版本控制（document management and revision control）
· 其他用途：制作照片模拟（photo simulations），用于 Environmental Impact Reports（环境影响报告）——将拟建建筑的 CAD 模型叠加到现有环境照片上；也用于 view corridors 遮挡分析与 shadow studies（阴影研究）。
· CAM（Computer-aided manufacturing，计算机辅助制造）
· 常见定义：用计算机软件控制机床及相关机械以制造工件。
· 广义定义：用计算机辅助制造工厂的所有操作，包括 planning（计划）、management（管理）、transportation（运输）、storage（仓储）。
· 主要目的：加快生产流程，使零部件与工装尺寸更精确、材料一致性更高；某些情况下仅使用所需原材料（减少浪费），同时降低能耗。
· 流程顺序：CAD →（有时经 CAE 验证）→ CAM；CAD 生成的模型、CAE 验证后的模型可输入 CAM 软件，由 CAM 控制机床。
· 传统上 CAM 被视为 NC（numerical control，数控）编程工具：用 CAD 生成的 2-D/3-D 模型生成 G-code（G 代码）驱动 CNC 机床。
· 简单设计（如 bolt circles 螺栓圆、basic contours 基本轮廓）无需导入 CAD 文件。
· CAM 不取代制造工程师、NC 程序员、machinist（机加工人员）等专业人员；而是通过可视化、仿真与优化工具提升其生产力并培养新人员技能。
· CAE（Computer-aided engineering，计算机辅助工程；德文 rechnergestützte Entwicklung，计算机辅助开发）
· 定义：涵盖技术领域工作流程中所有形式的计算机辅助手段，包括：
· CAD（rechnerunterstützte Konstruktion，计算机辅助设计）
· Digital Mock-Up（DMU，数字样机）：Ein- und Ausbauuntersuchungen（装配/拆卸检查）、Kollisionsprüfungen（碰撞检查）、Baubarkeitsprüfungen（可制造性检查）
· Diskretisierungssoftware（离散化软件）：Erstellung von Berechnungsgittern（计算网格生成）
· Kinematik- und Starrkörpersimulationen（运动学与刚体仿真）
· Mehrkörpersimulation（MKS，多体仿真）
· 零部件与组件的机械受力分析（FEM，有限元法）
· Strömungssimulationen mit CFD（Computational Fluid Dynamics，计算流体力学流动仿真）
· Thermische Simulationen（热仿真，FEM 与 CFD）
· Fluid Structure Interaction（FSI，流体-结构耦合，含流体、结构与热耦合）
· Elektroniksimulationen（电子仿真：电路开发与仿真）
· Elektromagnetismusimulationen（电磁仿真：FEM、FDTD、FIT）
· Statistische Simulationen（统计仿真：Design for Six Sigma，六西格玛设计）
· NC-Programmierung und -Simulation（数控编程与仿真，即 CAM）
· Rechnergestützte Qualitätssicherung CAQ（计算机辅助质量保证）
· Fertigungsprozesssimulationen（制造工艺仿真：computer-aided process engineering，CAPE）
· Ergonemieanalyse（人机工程分析：Human Modeling，人体建模）
· Verwaltung von Simulationsdaten（仿真数据管理：Simulationsdatenmanagement）
参考：来源：CAD.pdf｜专业：机械工程｜课程：CAD/CAM 计算机辅助设计与制造
APS 大四上
核心内容
企业专家讲座 Invited lectures from enterprises The purpose of this course is to let students not be limited to theoretical knowledge, but to get in touch with society and enterprises. The university invited some experts from enterprises and the school to introduce the advanced technology of enterprises and share some stories to us and improve students' social responsibility and broaden students' horizons What impressed me most was that our dean （地） made one of his patents for free. This patent could save large companies millions of dollars a year. This shows the social responsibility of an engineer . We were asked to write notes and comments. These materials are the basis of our final score. The reason I got a poor score is that maybe I didn't interact with experts because I don't like talking in front of many people. Another possibility is that what I wrote was not deep enough, just recorded what the experts said. 无机材料与人类文明进步 Inorganic materials and progress of human civilization This is a general education course. In this course we learned about the history and development of inorganic materials. Like volcanic ash, ceramics, and diamonds. 热质交换原理与设备 Heat and mass transfer principles and Equipment This is a specialized elective course. And it's an open book exam. Through this course, I learned the basic knowledge of mass and heat transfer. I learned about some equipment such as air conditioning 。 我们学习了热传递的三种方式，热对流，热传导，热辐射 。我会画一个简图来区分这三种方式。这是 火，如果我们把手放在火的上方，我们会感受到热量，这就是热对流。热对流的介质是流体
参考：来源：APS 大四上.pdf｜专业：机械工程｜课程：APS 大四上
APS 实践课
核心内容
电子工艺实习 Preliminary Circuit Implementaion 这是一门实践课，而且对我来说非常有意思。我们每个人都得到一包零件，一个电路板还有一个说明书。我们被要求做一个收音机，包括零件的装配和电路板的焊制。这对我来说就像在玩乐高，我只需要照着说明书一步一步。最后根据收音机的信号强弱打分 This is a practical course, and it is very interesting for me. Each of us gets a package of parts, ǒa circuit board and an instruction manual. We were asked to make a radio, including the assembly of parts and the welding of circuit boards. This is like playing Lego to me, I just need to follow the instructions step by step. Finally, score based on the strength of the radio signal 机械制造工艺 Mechanical manufacturing process design In this lesson we were asked to design a fixture . We were divided into many groups ,and four students a group .Our task is to design a milling jig for a workpiece . First we should know that the workpiece has six degrees of freedom. The fixture is used to fix the workpiece, and all six degrees of freedom need to be limited. The shape of the workpiece looks like this . So at the left of the jig , I choose a long V type block ,and on the right ,is a movable V type block ， It has thread on it and can clamp the workpiece by turn the hand bar . At the bottom of the jig I used a self-support device . In the process of positioning, it can adapt to the positioning datum of the workpiece. And there are two U typ grooves on the bottom for fixing on the milling machine . And all the parts are the standard parts ,the parameter of them can be found on the book 机电控制综合设计实践 Mechanical and electrical control integrated
参考：来源：APS 实践课.pdf｜专业：机械工程｜课程：APS 实践课
APS 电子类
核心内容
电子技术基础 The base on electronics 通过这节课我学习了基本的电子元件，比如说 电阻，电容，二极管，这部分的重点是二极管的原理， 或者说是PN结的原理。还学习了逻辑电路和组合电路。 Through this class, I learned some basic electronic components, the focus is the diode, and we learned its working principle. such as PN junction 。I also learned about logic circuits and combinatorial circuits 二极管是用半导体材料制成的，它具有单向导电性能。功能的实现是通过PN结，。PN结就是将P型半导体与N型半导体制作在同一块半导体上，接触面上就形成了PN结。接反向电压时，内部电流一直增大，电子无法通过PN结. The diode is made of semiconductor material, which has unidirectional conductivity. The realization of the function is through the PN junction. This is a P-type semiconductor, and this is an N-type semiconductor and a PN junction is formed on the contact surface. When they touch, will diffuse. Will form a stable area The internal current direction is like this This area is the PN junction ，PN junction hinders the flow of electrons When we connect the forward voltage and the direction of the external current is like this, the PN junction will become smaller and smaller. The jammed vehicle becomes fewer and fewer In my understanding, the PN junction is like a traffic jam. It attracts most of the vehicles and cannot move, so the road is blocked. When we connect the reverse voltage, the traffic jam becomes more and more serious. 电阻可以分配电压，限制电流，保护电路 Resistor can distribute voltage, limit current, protect circuit 电容就像导体中的介质，则阻碍了电荷移动而使得电荷累积在导体上。电容越大，通过的频率也越高。电容的作用就是通交流隔直流 Capacitance is like the medium in a conductor, it hinders the movement of electric charge and makes t
参考：来源：APS 电子类.pdf｜专业：机械工程｜课程：APS 电子类
金属加工机床与机械制造基础 · APS 金属加工机床Fundamentals of machinery manufacturing
核心内容
datum 基准 三个基准面 rotating 旋转 vector 矢量 deputy 副 velocity 速度 distinguish 区分 orthogonal 正交 tangent想切 perpendicular 垂直 impact 冲击 carbides 碳化物 alloy 合金 resistance molding materials brittle metal deformation Friction Angle Fundamentals of machinery manufacturing 这门课主要分为四个模块：金属切削的原理，金属切削的刀具，金属切削的过程 ，金属切削的方法和装备（各式机床） This course is mainly divided into four modules: the principle of metal cutting, the method of metal cutting, the cutting tool of metal cutting, and the equipment of metal cutting (various machine tools). 金属切削的原理：这个部分主要涉及的是基础概念 。例如：主运动和进给运动，三面两刀一 尖，还有三个基准面，两个重要的角度 ，还有切削层的三个参数。 Principles of metal cutting: This section is mainly about basic concepts. For example: main motion and feed motion, three sides, two edges, one point, and three datum（哋tum，基准） planes. and two important angles . 主运动是刀具和工件之间的主要的相对运动，一般来说只有一个。比如说车削时工件的旋转运动 The main motion is the main relative motion between the tool and the workpiece, generally there is only one. For example, the rotating motion of the workpiece during turning 三面两刀一尖：三面指的是前刀面，后刀面还有副后刀面。两刃指的是主切削刃还有副切削刃，一尖 指的是刀尖 Three sides, two knives and one point: the three sides refer to the front knife face, the back knife face and the deputy （da劈体，副）back knife face. The two edges refer to the main cutting edge and the deputy cutting edge, and one point refers to the tool nose . 如何区分三个面，我们可以画一个草图，根据书上的定义，切屑流过的表面为前刀面 How to distinguish the three sides，We can draw a rough draft . 还有三个基准平面 And there are three datum planes ,called the base plane, the c
参考：来源：APS 金属加工机床Fundamentals of machinery manufacturing.pdf｜专业：机械工程｜课程：金属加工机床与机械制造基础
APS力学
核心内容
材料力学 Mechanics of materials 1.特点：外力与杆的轴线重合 ，杆会沿着轴的方向变长或缩短。 然后我们学习了使用截面法求轴力 。首先将轴截开，取其中一段，然后受力分析，列出平衡方程 。 我们还需要知道，拉力为正，压力为负。 然后我们可以分段画出轴力图。 2. 外力偶矩的计算可以分为两种。一种是可以直接计算。另一种是对于传动轴 ，我们一般只知道功率和转速。所以我们需要根据功率和转速求出外力偶矩。我们需要列出等式，电机的输出功等于外力偶矩做的功。求出外力偶矩后，我们便可以用截面法，求得扭矩 。之后我们可以利用右手螺旋法则判断 扭矩的方向。并画出扭矩图。 3.外力与杆的轴线垂直。比如说对一个简支梁。通过受力分析，我们先求出A,B两点的支座反力 ，接着 我们利用截面法将杆分为两部分，列出关于力和力矩的平衡方程 。我们便可以求出一个力和一个力矩。这个力被称为剪力，这个力矩为弯矩。剪力顺时针为正，逆时针为负。如果弯矩使轴凹，为正， 反之为负。 Through this course, I have learned about the extension and compression of the rod, the torsional deformation of the rod, and the bending deformation of the rod. At the same time, we learned how to calculate axial force, torque, shear force, bending moment, and determine their direction. The first case is the tension and compression of the rod. The external force coincides with the axis of the rod Then we learned to use the section method to find the axial force. First cut off the shaft, take one section, and then analyze the force, and list the balance equation. In this way, we can calculate the axial force of a certain section.We also need to know that tension is positive and pressure is negative. Then we can draw the axial force diagram . 2. In this case, we must first calculate the external couple moment 。The calculation of external couple moment can be divided into two types. One is that it can be calculated directly. The other is for the drive shaft, we generally only know the power and speed. So we need to find the external couple moment accor
参考：来源：APS力学.pdf｜专业：机械工程｜课程：APS力学
APS大一
核心内容
工程图学 通过这门课我们主要学习了如何使用三视图来反应一个三维物体。还有一些绘图的基本规则，比如绘制可见轮廓线时使用粗实线。使用细实线绘制剖面线和尺寸线。比如说如何绘制螺栓和螺纹，但是我们发现这些都是标准件，当我们使用绘图软件时可以使用源文件 Engineering Graphics Through this course, we mainly learned how to use three views to reflect a three-dimensional object. There are also some basic rules for drawing, such as using thick solid lines when drawing visible contour lines. Use thin solid lines to draw section and dimension lines. For example, how to draw bolts and threads, how to draw gears, but we found that these are standard parts, we can use source files when we use drawing software 线性代数 线性代数 通过这门课我学习了行列式和矩阵的计算，但是现在我只能记住最简单的计算。 Linear algebra Through this course I learned the calculation of determinants and matrices, but now I can only remember the simplest calculations. 乘积C的第m行第n列的元素等于矩阵A的第m行的元素与矩阵B的第n列对应元素乘积之和。 高等数学 Because too much time has passed, I can't remember complicated formulas, I only remember some basic calculations now. Such as derivation ，differential and integral The geometric meaning of the derivative is the slope of the curve at a certain point and the formul like this
参考：来源：APS大一.pdf｜专业：机械工程｜课程：APS大一
APS审核课程总结
核心内容
1 流体力学与液压传动/液压与气动课程设计 Fluid Mechanics and Hydraulic Transmission/Course Design of Hydraulics and Pneumatics 通过本课程的学习,熟悉液压技术，熟悉液压在工程机械领域的应用。能够分析 液压领域的相关问题。 Through the study of this course, I am familiar with hydraulic technology and the application of hydraulic in the field of construction machinery. Ability to analyze related problems in hydraulic field. 与液压有关的概念有很多 There are many concepts related to hydraulic pressure hydraulic transmission 液压传动：利用液体压力势能进行的传动 hydraulic transmission：Transmission using liquid pressure potential energy 液力传动：利用液体的动能进行传动 hydrodynamic drive：The kinetic energy of the liquid is used for transmission 液压系统的组成 Composition of hydraulic system 能源装置：将机械能转化为液体压力能，液压泵 Energy device：Convert mechanical energy into liquid pressure energy。fluid pump。 执行装置：把液体压力能转换成机械能并对外做功，液压缸和液压马达 executive device：The pressure energy of the liquid is converted into mechanical energy And do work。hydraulic cylinder and hydraulic motor。 控制调节装置：控制油液的压力、流量、和流动方向。换向阀、调节阀、溢流阀 Control regulating device：Control oil pressure, flow rate, and flow direction。reversing valve、 regulating valve、overflow valve 辅助装置：保证液压系统正常运行。油箱过滤器、油管 auxiliary device：Ensure the normal operation of hydraulic system。Fuel tank filter、oil tube 工作介质：液压油或其他液体。 working medium：Hydraulic oil or other liquid。 液压马达 hydraulic motor 将液体压力能转变为机械能并对外做功，一般要求能正反转。 Hydraulic motors convert liquid pressure energy into mechanical energy and do work，Hydraulic motors are generally required to turn forward and reverse。 工
参考：来源：APS审核课程总结.pdf｜专业：机械工程｜课程：APS审核课程总结
机械原理 · APS机械原理 theory of machines and mechanisms
核心内容
theory of machines and mechanisms mechanisms 机构 connecting rod 连杆 diagram 简图 kenematic pair 运动副 revolute pair 转动副 prismatic pair 移动副 cam pair 在这本书中我学到的主要知识有机构的结构分析，机械的效率与自锁，连杆机构还有齿轮机构 The main knowledge I learned in this book includes structural analysis（呃拿了C4） of mechanism , mechanical self-locking, linkage mechanism and gear mechanism 一、机构的结构分析 首先我们应该学会画机构的运动简图然后会计算自由度并能够判断机构是否具有确定的运动。 First of all, we should be able to draw the motion diagram of the mechanism and then be able to calculate the degrees of freedom and be able to determine whether the mechanism has certain motion. 首先我们应该知道移动副分为高副和低副。点接触或者线接触为高副，比如说移动副和转动副 面接触为低副,比如说凸轮副和齿轮副 。 First we should know that the kenematic （凯南卖踢克）pair is divided into higher pair and lower pair.High pairs have higher degrees of freedom . Point contact or line contact is higher pair, Such as cam pair and gear pair . surface contact is lower pair. such as revolute pair and prismatic pair . 在平面机构中，每个自由构件有三个自由度，每个低副提供两个约束，每个高副提供一个约束 。那么 我们可以得到一个关于自由度的公式。 In a planar mechanism, each free link has three degrees of freedom, each lower pair provides two constraint , and each higher pair provides one constraint. So we can get a formula of the degrees of freedom. F=3n -（2pl+ph） 但是我们在计算自由度的时候，我们还要注意一些情况。 1.复合铰链 （画图） 三个构件组成，有两个转动副 2.要去除局部自由度 （画图） 比如说在凸轮机构中滚子作用为减小摩擦，并不影响运动 3.要去除虚约束 （画图）有些约束是重复的被称为虚约束 所以完整的公式为 But when we calculate the degrees of freedom, we have to pay attention to some special cases . 1. Composite joint (drawing) In calculation, t
参考：来源：APS机械原理 theory of machines and mechanisms.pdf｜专业：机械工程｜课程：机械原理
机械原理·课程总结笔记
核心内容
【机械原理】
一、平面机构（planar mechanism）与运动链
1. 机构（mechanism）：有机架（frame）的运动链。运动链（kinematic chain）：有两个以上构件连接的系统。机构中的构件分为原动件（driving links）与从动件（driven links）。
2. 自由度（Degree of Freedom）：F = 3n - 2P_L - P_H。其中F为自由度，n为构件数，P_L为低副数，P_H为高副数。低副以面接触，高副以点或线接触。
二、运动分析
以四杆机构ABCD为例，A、B、C、D为铰链，杆件编号1、2、3。速度关系：Vc2 = Vb2 + Vc2B2。方向：Vc2垂直CD，Vb2垂直AB，Vc2B2垂直BC；大小：Vc2未知，Vb2 = ω·l_AB，Vc2B2未知。由此可求出Vc。绝对运动 = 相对运动 + 牵连运动。
三、凸轮机构（Cam Mechanisms）
1. 名词概念：从动件（follower）；基圆为理论廓线上最小半径为半径的圆；升程为从动件从低位升到高位置的距离；推程运动角为升程时凸轮的转角；远休止角为从动件在高处不动时的转角；回程运动角为从动件从高位置到低位置的转角；近休止角为从动件在低处不动时的转角。
2. 设计凸轮：通过从动件位移图象来设计。步骤：先画基圆、偏心圆；按图将圆以角度分开；等分圆，在圆中找到对应高度；图中量取高度，从基圆往上加；连成线。
四、齿轮机构（Gear Mechanisms）
1. 传动特点：传动准确平稳；承载能力大；寿命长。节点为两齿轮V1、V2相同的点。传动比 i = ω1/ω2 = O2C/O1C，C是节点，O1C、O2C是节圆半径。
2. 标准齿轮参数：模数 m = p/π，p为齿距，单位mm；齿数z；分度圆直径 d = mz；齿顶圆 da = d + 2ha；齿根圆 df = d - 2hf；齿槽宽 e = πm/2；齿厚 s = πm/2；齿距 p = πm；齿顶高 ha = ha*·m；齿根高 hf = (ha*+c*)m；全齿高 = ha + hf；齿顶高系数 ha* = 1；顶隙系数 c* = 0.25；压力角国标一般20°。
3. 正确啮合条件：模数相等，压力角相等。保证连续传动：前一对齿还在啮合时，后一对齿已进入啮合，即重合度>1。重合度就是同时参与啮合的齿轮对数。重合度↑ → 传动平稳性↑ → 承载能力↑。
4. 加工齿轮方法：齿轮插刀、齿条插刀、滚刀。
五、轮系
轮系分定轴轮系、周转轮系。定轴轮系各轮轴线位置固定；周转轮系有齿轮的轴线绕其他齿轮转动。定轴轮系传动比：i = ω1/ω5 = (z2·z3·z5)/(z1·z2·z3·z4) = 从动轮齿数相乘 / 主动轮齿数相乘，方向判断依图示齿轮1、2、3、3'、4、4'、5。
参考：来源：WM_HDU-Len 课程总结.pdf｜专业：机械工程｜课程：机械原理
英语自我介绍（WM） · WM_英语介绍1
核心内容
一、机电一体化系统设计（Electrical and mechanical system design） 机电一体化系统设计是我们专业的选修课。通过这门课的学习，我们我们建立了机电一体化设计思想。这门课综合了我们其他的一些课程，比如一个系统是由动力源、执行器、 机械、传感器和电子控制元件组成。这些都是以前我们各个课程都学过的，比如执行器是 《机电传动与控制》中学到的，电子控制元件则是《单片机原理》中学到的。这门课我们 主要复习了以前所学的知识，并介绍了典型装置的原理，比如丝杆螺母结构的应用和步进电机的原理。 Electrical and mechanical system design is an elective course of our major. Through the study of this course, we have established electrical and mechanical system design idea of products. This course combines our other courses. For example, a system is composed of power source, motor, mechanical, sensor, and electronic control part. These are learned in other courses, such as the motor was learned by electromechanical transmission control, and the electronic control part was learned by the Principle of Single-Chip Computer. In this course, we reviewed the knowledge we have learned before. And introduced the principle of some device, such as the screw nut device. And the principle of stepper motor. 1、它把旋转运动转变成直线运动，丝杆螺母分为滑动丝杆螺母和滚动丝杆螺母。滑动丝杆螺母的结构简单，成本低，但是摩擦大。滚动丝杆螺母的摩擦小，但是成本高。 It transforms the rotary motion into a linear motion. The screw nut is divided into a sliding screw nut and a rolling screw nut. The sliding screw nut has a simple structure, and has low cost, but the friction is large. The rolling screw nut has low friction, but it is expensive. 2、分别给 A、B、C 轮流通电，令转子转动。用程序控制脉冲信号，一个脉冲，转动一下， 频率越快，转速越快。步距角是（公式） Power on to A, B, and C one by one and make the rotor rotate. Use the program to control the pulse, one pulse, it
参考：来源：WM_英语介绍1.pdf｜专业：机械工程｜课程：英语自我介绍（WM）
英语自我介绍（WM） · WM_英语介绍2
核心内容
一、机械控制工程（Mechanical Control Engineering） 机械控制工程是我们专业的必修课。这是用来研究系统的输入和输出之间的关系。通过这门课的学习，我们学习了系统的数学模型建立，传递函数，还学了时间和频率分析和 系统的判断系统的稳定性。 Mechanical control engineering is a required course of our major. This is used to study the relationship between the input and output of the system. Through the study of this course, we learned the mathematical model of the system, the transfer function, and also learned the time analysis and frequency analysis and the way to judge if the system is stable. 1、建立系统的数学模型的时候要先确定各个部分的输入和输出。写出各个部分的微分方程， 然后化简方程，把输出的放在左边，把输入的放在右边。比如这个系统，这是电阻和电容， 我们可以写出各个部分的微分方程，然后去掉 i，然后就有了这个，这个就是这个系统的微分方程。我们通过拉普拉斯变换来得到传递函数。我们还学了传递函数的简化。比如…… If we want to establish the mathematical model of the system, first we have to decide the input and output of each part. Write the differential equations for each part, then simplify the equations, place the output on the left, and place the input on the right. For example, this system, this is the resistor and capacitance, we can write the differential equations of each part, then remove i, and this is the differential equation of this system. We get the transfer function through the Laplace transform. We also learned the simplification of transfer functions. such as . 2、关于系统的时间响应分析，一阶系统的传递函数是……它的响应函数是……当输入信号 是 1 时，它的一阶系统的响应是...它的时间响应函数是……我们可以得到这个图，可以看到 T 越小，响应越快。T 是一阶系统的数值，比如刚刚那个系统就是 R 乘 C。 二阶系统是由一个耗能元件，两个储能元件。它的传递函数是……它的时间响应像这样... 它有上升时间，峰值时间，最大超调量，调整时间和振荡次数 As for the time analysis, the transfer function of the first-orde
参考：来源：WM_英语介绍2.pdf｜专业：机械工程｜课程：英语自我介绍（WM）