Components and Workflow of Automated Systems | 自动化系统的组成与工作流程

📚 Components and Workflow of Automated Systems | 自动化系统的组成与工作流程

An automated system is a combination of hardware and software that performs a task or controls a process with little or no human intervention. In computer science, the focus is on how sensors, controllers and actuators work together to sense the environment, make decisions and produce actions.

自动化系统是硬件与软件的结合，它能在很少甚至没有人工干预的情况下完成一项任务或控制一个过程。在计算机科学中，重点在于传感器、控制器与执行器如何协同工作：感知环境、作出决策并产生动作。

1. What Is an Automated System? | 什么是自动化系统

An automated system uses a computer or microprocessor to monitor a physical process, compare the current situation with a desired condition, and adjust outputs to achieve a target. This is often called a control system.

自动化系统使用计算机或微处理器来监测某一物理过程，将当前状况与期望状态进行比较，并调整输出来实现目标。这种系统通常也称为控制系统。

Automation is widely used in industry, homes and transport. The key benefit is that the system can run continuously, react quickly and produce consistent results without fatigue.

自动化广泛应用于工业、家庭和交通等领域。其关键优点是可以连续运行、快速反应，并且在不疲劳的情况下产生一致的结果。

2. Core Components Overview | 核心组成概览

The main components of a typical automated system are: sensors, signal conversion units, a controller, actuators and a feedback path. The controller is often a microprocessor or a microcontroller.

典型自动化系统的主要组成部分包括：传感器、信号转换单元、控制器、执行器以及反馈通路。控制器通常是一个微处理器或微控制器。

Sensor: collects data from the environment.

传感器：从环境中采集数据。
ADC / DAC: convert signals between analogue and digital forms.

ADC / DAC：在模拟量与数字量之间转换信号。
Controller: processes data and makes decisions.

控制器：处理数据并作出决策。
Actuator: carries out the physical action.

执行器：执行物理动作。
Feedback: sends output information back to the controller.

反馈：将输出信息送回控制器。

3. Sensors: The Sensing Unit | 传感器：感知单元

A sensor is a device that detects a physical quantity such as temperature, light, pressure or moisture and converts it into an electrical signal. Sensors are the “eyes and ears” of an automated system.

传感器是一种检测温度、光照、压力或湿度等物理量，并将其转换为电信号的设备。传感器是自动化系统的“眼睛和耳朵”。

Common sensors include temperature sensors, light-dependent resistors (LDRs), pressure sensors, humidity sensors, pH sensors, motion sensors and infrared sensors. Each sensor has a range and a level of sensitivity.

常见的传感器包括温度传感器、光敏电阻（LDR）、压力传感器、湿度传感器、pH传感器、运动传感器和红外传感器。每种传感器都有自身的量程和灵敏度。

Most sensors produce an analogue voltage or current that changes continuously with the measured quantity.

大多数传感器产生随被测物理量连续变化的模拟电压或模拟电流。

4. Signal Conversion: ADC and DAC | 信号转换：ADC 与 DAC

Because most sensors produce analogue signals, and microprocessors process digital data, an Analogue-to-Digital Converter (ADC) is required. The ADC samples the analogue signal at regular intervals and converts it into a binary value.

由于大多数传感器产生模拟信号，而微处理器处理的是数字数据，因此需要使用模数转换器（ADC）。ADC以固定时间间隔对模拟信号采样，并将其转换成二进制数值。

A Digital-to-Analogue Converter (DAC) performs the opposite task. It converts the controller’s digital output into an analogue voltage or current that can drive an actuator such as a motor or heater.

数模转换器（DAC）则执行相反的任务。它将控制器的数字输出转换成能够驱动电机或加热器等执行器的模拟电压或模拟电流。

The resolution of an ADC determines how accurately the analogue value is represented. A higher resolution gives more precise control.

ADC的分辨率决定了模拟量被表示的精确程度。分辨率越高，控制就越精确。

5. Controller: The Decision-Making Unit | 控制器：决策单元

The controller is usually a microprocessor, microcontroller or a computer. It stores the set point, reads the input from the sensor, compares it with the set point and decides what action to take.

控制器通常是微处理器、微控制器或计算机。它存储设定值，读取来自传感器的输入，将其与设定值比较，并决定应采取什么动作。

The controller uses a stored program to run instructions in a loop: read input, compare, decide, output. This loop runs fast enough to maintain real-time control.

控制器使用存储程序以循环方式运行指令：读取输入、比较、决策、输出。这个循环运行速度足够快，以维持实时控制。

For example, in a heating system, the controller receives the current temperature, compares it with the target temperature, and decides whether to turn the heater on or off.

例如，在加热系统中，控制器接收当前温度，将其与目标温度比较，并决定是打开还是关闭加热器。

6. Actuators: The Output Unit | 执行器：输出单元

An actuator is a device that converts an electrical control signal into a physical action. It is the component that makes things move, heat up, open, close or switch on and off.

执行器是一种将电控制信号转换为物理动作的设备。它是使物体移动、加热、打开、关闭或开启和关断的组件。

Common actuators include electric motors, fans, heaters, pumps, solenoids, valves and lamps. For example, a motor can open a greenhouse window, while a heater can raise the temperature.

常见的执行器包括电动机、风扇、加热器、水泵、电磁阀、阀门和灯泡。例如，电动机可以打开温室窗户，而加热器可以提高温度。

The actuator is often controlled through a DAC and an interfacing circuit because the controller’s output signal may be too weak to drive the actuator directly.

执行器通常通过DAC和接口电路来控制，因为控制器的输出信号可能太弱，无法直接驱动执行器。

7. Feedback and Control Modes | 反馈与控制方式

There are two main modes of control in automation systems: open-loop control and closed-loop control.

自动化系统中有两种主要的控制方式：开环控制和闭环控制。

In an open-loop system, the controller sends signals to the actuator without checking the result. For example, an automatic washing machine runs through a fixed timer sequence without measuring how clean the clothes are.

在开环系统中，控制器向执行器发送信号，但不检查结果。例如，自动洗衣机按固定时间顺序运行，而不测量衣物是否已经洗干净。

In a closed-loop system, feedback is used. The output is measured by a sensor and sent back to the controller. The controller compares the actual value with the set point and reduces any difference.

在闭环系统中，使用反馈。输出量由传感器测量，并送回控制器。控制器将实际值与设定值比较，并减小任何差异。

error = measured value − set point

Negative feedback is used so that when the measured value is too high, the system reduces the output; when it is too low, the system increases the output.

系统使用负反馈：当测量值过高时，系统减小输出；当测量值过低时，系统增大输出。

8. Workflow of an Automated System | 自动化系统的工作流程

The workflow can be described as a continuous cycle from sensing to acting. The table below shows the typical sequence in a closed-loop automated system.

工作流程可以描述为一个从感知到动作的连续循环。下表显示了闭环自动化系统中的典型顺序。

Stage \| 阶段	Component \| 组件	Action \| 动作
1. Sense \| 感知	Sensor \| 传感器	Measures the physical quantity and produces an analogue signal.
2. Convert \| 转换	ADC \| 模数转换器	Converts the analogue signal into digital data.
3. Compare \| 比较	Controller \| 控制器	Compares the digital value with the set point.
4. Decide \| 决策	Controller \| 控制器	Calculates the error and decides the required output.
5. Convert \| 转换	DAC \| 数模转换器	Converts the digital control signal into an analogue signal.
6. Act \| 执行	Actuator \| 执行器	Carries out the physical action, such as switching on a heater.
7. Feedback \| 反馈	Sensor \| 传感器	Measures the new condition and repeats the cycle.

This cycle repeats continuously, allowing the system to respond to changes in the environment in real time.

该循环不断重复，使系统能够实时响应环境的变化。

9. Worked Example: Automatic Greenhouse | 工作示例：自动化温室

An automatic greenhouse is a good example of a closed-loop automation system. Its goal is to keep temperature, humidity and light levels within target ranges.

自动化温室是闭环自动化系统的一个很好的例子。其目标是将温度、湿度和光照水平保持在目标范围内。

For temperature control, a temperature sensor measures the air temperature. The ADC converts the reading and passes it to the controller. If the temperature is above the set point, the controller switches on a fan or opens a vent. If it is below the set point, it switches on a heater.

在温度控制中，温度传感器测量空气温度。ADC转换读数并传送给控制器。如果温度高于设定值，控制器打开风扇或开启通风口；如果温度低于设定值，则打开加热器。

For light control, an LDR measures light intensity. If the light is too low, the controller switches on artificial lamps; if it is too high, the controller may pull down blinds.

在光照控制中，光敏电阻（LDR）测量光照强度。如果光照太低，控制器打开人造灯；如果光照太高，控制器可能放下遮阳帘。

Humidity can be controlled in a similar way using a humidity sensor and a watering or misting system.

湿度可以类似地使用湿度传感器和浇水或喷雾系统来控制。

10. Real-World Applications | 实际应用

Automated systems are found in many areas of everyday life and industry.

自动化系统广泛存在于日常生活和工业的许多领域。

Central heating: temperature sensor + controller + boiler actuator.

中央供暖：温度传感器 + 控制器 + 锅炉执行器。
Traffic lights: timed sequence or sensor-controlled signals.

交通信号灯：定时顺序或传感器控制的信号灯。
Industrial robots: sensors and controllers guide precise movement.

工业机器人：传感器和控制器引导精确运动。
Smart irrigation: moisture sensors trigger watering systems.

智能灌溉：湿度传感器触发浇水系统。
Self-driving cars: cameras, radar and processors make real-time decisions.

自动驾驶汽车：摄像头、雷达和处理器进行实时决策。

11. Key Terms and Exam Tips | 关键术语与考试提示

In a CIE Computer Science exam, you may be asked to identify components in a control diagram or explain a workflow sequence. It is important to use the correct technical terms.

在CIE计算机科学考试中，你可能会被要求在控制图中识别组件，或解释工作流程顺序。使用正确的技术术语非常重要。

Key terms include: sensor, ADC, DAC, controller, set point, error, actuator and feedback.

关键术语包括：传感器、ADC、DAC、控制器、设定值、误差、执行器和反馈。

When describing a workflow, always mention the order: sense, convert, compare, decide, convert, act, feedback. Avoid jumping straight from sensor to actuator without explaining the controller’s role.

描述工作流程时，一定要按照顺序说明：感知、转换、比较、决策、转换、执行、反馈。不能跳过控制器的作用，直接从传感器跳到执行器。

Remember that an open-loop system has no feedback, while a closed-loop system uses feedback to reduce the difference between the actual value and the set point.

请记住：开环系统没有反馈，而闭环系统使用反馈来减小实际值与设定值之间的差值。

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Stage \| 阶段	Component \| 组件	Action \| 动作
1. Sense \| 感知	Sensor \| 传感器	Measures the physical quantity and produces an analogue signal.
2. Convert \| 转换	ADC \| 模数转换器	Converts the analogue signal into digital data.
3. Compare \| 比较	Controller \| 控制器	Compares the digital value with the set point.
4. Decide \| 决策	Controller \| 控制器	Calculates the error and decides the required output.
5. Convert \| 转换	DAC \| 数模转换器	Converts the digital control signal into an analogue signal.
6. Act \| 执行	Actuator \| 执行器	Carries out the physical action, such as switching on a heater.
7. Feedback \| 反馈	Sensor \| 传感器	Measures the new condition and repeats the cycle.

Components and Workflow of Automated Systems | 自动化系统的组成与工作流程