Chapter 7
Two experiments
The first one is on April 8, Friday The last one is on May 19, Thursday
Chapter 1: introduction to control stems
1.1 principle of automatic control system 1.2 Structure of control system 1.3 Control systems’ characteristics 1.4 Types of control systems
E
Turn to page 4，look at 1.2.2
1.3 Control systems’ characteristics特性
1. Stability 稳定性 If the difference between the 稳定性:
controlled variable and the reference decays to zero, or the output converges to a limit, the system is said to be stable. Eliminating instability is the first concern of the control system designer.
Sliding collar 滑动轴环 Steam engine
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3. schematic diagram 示意图 the steam governor 示意图of
Steam supply Desired speed Actual speed Steam engine
Mechanical linkage
In the broadest sense, a control system is any interconnection of components to provide a desired function. Substance, energy and information are the fundamental elements of any control system. If the correcting action is performed by a human, a system is said to be manually controlled手动控 制的. Otherwise, it is automatically controlled自 动控制的.
3. Dynamics properties动态特性 动态特性: 动态特性
Dynamics properties indicate the transient response 瞬态响 应characteristics of control systems, usually relative to step input阶跃输入.
Fundamental of Mechanical Control Engineering
Jhx 2011.02
This obligatory course is designed to guide the students in gaining the following main points
Dynamic properties 动态性能； Process control system 过程控制系统； Servomechanisms 随动系统 Continuous control system 连续控制系统 Discrete control system 离散控制系统 Input signal 输入信号 Output signal 输出信号 Actuating signal 作用信号（控制信号） Controller 控制器
Chapter 2
Chapter 3
Chapter 4
Experience and competence with frequency response频率响应, frequency characteristics 频率特性and its graphical methods—Nyquist diagrams乃氏图 and Bode diagrams波德图; appreciation of performance specifications in frequency domain频域 and the relationship between performance indices 性能指标in time domain 时域and specifications in frequency domain. Thorough acquaintance with Routh-Hurwitz stability criterion 劳斯-赫尔维兹稳定性判据 and the ability to determine root distributions 根的分布and to find relative stability相对稳定 性.
Chapter 1
Familiarity with the main concepts related to Control and Control Engineering. Familiarity with the transfer function 传递函数 for linear, time-invariant线性时不变 systems, including asymptotic stability 渐进稳定性concepts. Capability with block diagram manipulations方框 图化简 and the use of Mason’s gain rule梅逊公式. Confidence in the use of Laplace Transform 拉氏 变换methods in system response calculation 计算 系统响应and an understanding of commonly used response components.
1.1 principle of automatic control system 1.1.1 control systems
Control systems exit in our daily life. We can get objects on desks exactly because our hands moved by the exact instructions which come from our brain through observation. This control system is provided by nature. Man-made control systems人工控制系统: a power steering动力转向系统 system of a car is designed to control the angle of the car’s front wheels, hence the running direction is controlled.
Butterfly valve
Rotating ball
1.2 Structure of control system 1.2.1 Schematic diagram of a typical automatic control system
期望值 Desired value R input 输入值 放大器（控 放大器（ 制器） 制器） Amplifier B Sensors/ transformers 传感器/变换器 传感器 变换器 干扰 Disturbance 执行机构 Actuator Controlled object 被控对象 实际值 Actual value C output 输出值
Some new words
Automation 自动化； feedback 反馈； negative feedback 负反馈； positive feedback 正反馈； open-loop control system 开环控制系统； closed-loop control system 闭环控制系统； Stability 稳定性； Accuracy 精度；
1.1.2 principle of automatic control systems
An example of the speed control of a steam engine: 1. manual control system:
Steam supply蒸汽供给 蒸汽供给 Steam valve 蒸汽阀 Adjusted by a human人工调节 人工调节
Steam engine 蒸汽引擎
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2. automatic control system:
Non-rotating Collar adjustable非旋转可 非旋转可 调节轴环 in height to set desired speed
Steam supply Steam valve
Rotatinpter 5
Chapter 6
Appreciation of the feedback反馈 concept and its importance; familiarity with steady-state error 稳态误差concepts and calculation; an acquaintance with system parameter 系统参数 sensitivity, susceptibility to disturbances干扰, and the use of performance specifications. Familiarity with classical compensation 调节 methods and real understanding of the principles guiding compensator 调节器design.