1 / 19

ME451 Kinematics and Dynamics of Machine Systems ME451 的運動學和機械系統動力學

ME451 Kinematics and Dynamics of Machine Systems ME451 的運動學和機械系統動力學. 授課老師 : 謝銘源 組員 : 黃靖凱 莊沛語. Why/How do bodies move?. Why? The configuration of a mechanism changes in time based on forces and motions applied to its components Forces Internal (reaction forces)

emma-parks
Download Presentation

ME451 Kinematics and Dynamics of Machine Systems ME451 的運動學和機械系統動力學

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ME451 Kinematics and Dynamics of Machine Systems ME451的運動學和機械系統動力學 授課老師: 謝銘源 組員: 黃靖凱莊沛語

  2. Why/How do bodies move? Why? The configuration of a mechanism changes in time based on forces and motions applied to its components Forces Internal (reaction forces) External, or applied forces (gravity, compliant forces, etc.) Motions Somebody prescribes the motion of a component of the mechanical system Recall Finite Element Analysis, boundary conditions are of two types: Neumann, when the force is prescribed Dirichlet, when the displacement is prescribed How? They move in a way that obeys Newton’s second law Caveat: there are additional conditions (constraints) that need to be satisfies by the time evolution of these bodies, and these constraints come from the joints that connect the bodies (to be covered in detail later…)

  3. Putting it all together… MECHANICAL SYSTEM = BODIES + JOINTS + FORCES THE SYSTEM CHANGES ITS CONFIGURATION IN TIME WE WANT TO BE ABLE TO PREDICT & CHANGE/CONTROL HOW SYSTEM EVOLVES

  4. Examples of Mechanisms 當我說“機械系統”或“系統”這是什麼意思？ What do I mean when I say “mechanical system”, or “system”? 切割行程 雨刮器 工作部件 搖桿耦合 齒輪 左蹺板 曲軸 右蹺板 曲軸耦合器 雨刷機構 Windshield wiper mechanism 快速返回插齒機構 Quick-return shaper mechanism

  5. 固定齒輪 路徑 行程運動 轉動曲柄 連接 鋸齒齒輪 機構 雨刷連動方式

  6. More examples … 球形接頭 活塞杆 平移關節 支撐主軸裝配 降低控制 McPherson Strut Front Suspension 麥弗遜式支柱前懸掛 Schematic of car suspension 汽車懸架示意圖

  7. 麥弗遜式懸掛系統的優點是：結構簡單 ，懸掛重量輕和占用空間小，車輪跳動時前輪定位參數變化小，有良好的操縱穩定性。 懸挂係統的組成 一、彈簧   二、避震器   三、防傾桿   四、連桿

  8. 懸掛係統汽車，車架與車橋或車輪之間的一切傳力連接裝置的總稱，其功能是傳遞作用在車輪和車架之間的力和力矩，並且緩衝由不平路面傳給車架或車身的衝擊力，並衰減引起的震動，以保證汽車平順行駛。懸挂係統應有的功能是支持車身，改善乘坐的感覺，不同的懸挂設置會使駕駛者有不同的駕駛感受。外表看似簡單的懸挂係統綜合多種作用力，決定著轎車的穩定性、舒適性和安全性，十分關鍵之一。

  9. More examples … Interest here is in controlling the time evolution of these mechanical systems 機器人機械手 Robotic Manipulator 發動機的截面 Cross Section of Engine

  10. Nomenclature(命名法) Mechanical System, definition: A collection of interconnected rigid bodies that can move relative to one another, consistent with joints that limit relative motions of pairs of bodies Why type of analysis can one speak of in conjunction with a mechanical system? Kinematics analysis (運動學分析) Dynamics analysis (動力學分析) Inverse Dynamics analysis (反向動力學分析) Equilibrium analysis (均衡分析)

  11. Kinematics Analysis (運動學分析) Concerns the motion of the system independent of the forces that produce the motion Typically, the time history of one body in the system is prescribed We are interested in how the rest of the bodies in the system move Requires the solution linear and nonlinear systems of equations 雨刷機械

  12. Dynamics Analysis(動力學分析) Concerns the motion of the system that is due to the action of applied forces/torques Typically, a set of forces acting on the system is provided. Motions can also be specified on some bodies We are interested in how each body in the mechanism moves Requires the solution of a combined system of differential and algebraic equations (DAEs)

  13. Inverse Dynamics Analysis(反向動力學分析) It is a hybrid between Kinematics and Dynamics Basically, one wants to find the set of forces that lead to a certain desirable motion of the mechanism Your bread and butter in Controls… 這是一個運動學和動力學之間的混合 Windshield wiper mechanism 機器人機械手 Robotic Manipulator

  14. End: Chapter 1 (Introduction)Begin: Review of Linear Algebra 結束：第1章（引言）開始審查線性代數

  15. Why bother with vectors/matrices? Kinematics (and later Dynamics), is all about being able to say at a given time where a point is in space, and how it is moving. Vectors and matrices are extensively used to this end. Vectors are used to locate points on a body. Matrices are used to describe the orientation of a body.

  16. Geometric Vectors What is a Geometric Vector? A quantity that has two attributes: A direction A magnitude VERY IMPORTANT: Geometric vectors are quantities that exist independently of any reference frame ME451 deals almost entirely with planar kinematics and dynamics We assume that all the vectors are defined in the 2D plane

  17. Geometric Vectors: Operations • What can you do with geometric vectors? • Scale them • Add them (according to the parallelogram rule) • Addition is commutative • Multiply two of them • Inner product (leads to a number) • Outer product (leads to a vector, perpendicular on the plane) • Measure the angle  between two of them

  18. 單位坐標向量（短途旅行）Unit Coordinate Vectors(short excursion) 單位坐標向量：一個用來表達所有其他向量的單位向量 在這個類中，以簡化我們的生活中，我們使用兩個正交的單位向量 一個向量分解為組件 和沿X和Y軸 命名 : 和 被稱為笛卡爾向量的組件 符號約定：在本類中，向量/矩陣粗體，標量不（通常是他們以斜體）

  19. 幾何向量:操作Geometric Vectors: Operations 兩個向量的積 關於兩個向量之間的的角度，請注意 兩個向量的點積是可交換  由於坐標單位矢量之間的角度是 / 2：

More Related