If a university wants to choose to study automation, what books can it read in advance?

Universities want to choose to study Automation , What books can you read to know in advance ？

Automation is a big category , There are many technologies . For example, the automatic face recognition door opening system of many community gates , Is one of the applications of Automation . In Automation , Automatic control accounts for a large proportion .

The subject is obviously a high school student , Let me tell high school students about automatic control .

1. Examples of water level control

Let's look at the picture below ：

chart 1： Pool level control

chart 1 It's a pool . We expect that the outflow of water will not be interrupted , And to ensure that the minimum water pressure P, So we must keep the water level in the pool between the highest and lowest water levels . obviously , We can use the water level measuring device , When the water level is lower than the minimum water level, the water pump will be started to inject water into the pool , When the water level exceeds the maximum water level, stop the pump . In the process , The water inflow per unit time must be greater than the water outflow .

Because of the figure 1 The water level in is fluctuating between the highest water level and the lowest water level , We call this kind of control bit control .

If we raise the lowest water level and approach the highest water level , Even the two are merged , Then the water level control at this time will realize continuous control within its allowable deviation range .

Pass diagram 1, We see two ways of control , Positional control and continuous control .

For continuous control , The water level H Of course, it is our control target . The water level is collected by the sensor , We subtract the control line from the collected real-time water level position （ Maximum water level ） Get the water level deviation ΔH. According to the deviation ΔH Size , Let's control the speed of the pump motor , So as to regulate the flow of water Q1： deviation ΔH The bigger it is , The greater the inflow flow ; deviation ΔH The smaller it is , The smaller the inflow flow . When the deviation ΔH When it's zero , The water pump stops . We call this control method proportional control . In this way , We can realize the continuous control of the water level of the pool .

However , When the water level changes suddenly , Proportion control alone is not competent . We express this kind of abrupt variable by differential , namely dH/dt. Once a mutation occurs , The control system starts the water pump to increase the flow according to the sudden variable , We call this kind of control differential control .

When the water level is sufficiently close to the control point , The deviation is small , Proportion control is no longer competent . At this point, we accumulate the deviation with integral , When the deviation accumulates to a certain extent, we adjust the pump flow to eliminate the deviation . We call this kind of control integral control .

The above proportion 、 Integral and differential control methods are used PID To express .

Let's look at the picture below ：

chart 2：PID Control curve

chart 2 in , The dotted line is the control line . We see two dashed lines , It is used to characterize the deviation of control , Or control accuracy . chart 2 For different proportion coefficients Kp Several curves are given , We see that the larger the proportion, the greater the overshoot of the control quantity . so ,PID The specific parameters of measurement and control technology are very particular .

2. What technologies and courses are involved in automatic control ？

In the above example of water level control , We should be able to feel that automatic control is related to a lot of knowledge and Technology . So for general automatic control system , What knowledge is it related to ？ Let's list and analyze below ：

The first is power supply and distribution technology and motor control technology , It is related to electrical engineering 、 Power transformer 、 Power supply and distribution system 、 Switching technology is related .

The second is sensor technology , It is related to analog electronic technology 、 Digital electronic technology , And the acquisition technology of electric parameters and non electric parameters .

The third is single chip technology 、PLC Technology, data exchange and computer control principle .

The fourth is the principle of automatic control , This is the core technology .

The fifth is the working principle and process conditions of mechanical equipment , For example, water pump unit 、 Piping system, etc , And operation process requirements, etc .

Let's discuss it in relative depth below .

（1） circuit analysis

Circuit analysis is a basic course of Electrical Technology .

We read DC circuit and AC circuit in Middle School , But that's just the most basic concept , Even the threshold of circuit analysis has not entered .

We are in circuit analysis , Will read voltage source and current source , There are also controlled sources . Will read the resistance 、 Characteristics of inductance and capacitance in DC circuit , And the method of solving DC circuit . For AC circuits , Due to the existing amplitude changes of voltage and current , There are also phase and frequency changes , For this reason, we will learn a special parameter called phasor .

Notice that the phasor is not a vector or a vector . For example, torque in mechanics is vector , It is force 、 The product of the force arm and the sine of the included angle , We call it the cross product of vectors . The cross product of current phasor and voltage phasor is reactive power , It's scalar . It can be seen that the phasor is not a vector or a vector .

We will also learn the response of the circuit , And the relationship between electrical parameters and frequency .

Learn circuit analysis , You need a basic mathematical tool , It's Higher Mathematics .

（2） Analog Electronics 、 Digital electronic technology and power electronic technology

These three courses are the basic courses for us to further study circuit design . Through the study of these three courses , Know how to design transistor circuits 、 Operational amplifier circuit 、 Circuits composed of various basic digital integrated chips , And the principle of thyristor rectification and control . We can further learn about frequency converters that are widely used 、 Working principle of soft starter .

You can say that , These three courses are the core technologies of contemporary industrial control instruments and control devices .

（3） Single chip microcomputer 、PLC Control technology and data exchange technology

SCM is widely used in industrial control , Even our washing machine and refrigerator have single-chip computers , It can be seen that the importance of SCM technology .

PLC It is a special industrial product of single chip microcomputer , It has extremely high anti electromagnetic disturbance ability .

Electromagnetic disturbance , It has two aspects , One is the ability of the equipment to resist electromagnetic interference , The second is that it will not generate electromagnetic signals to interfere with other equipment .

utilize PLC, Program control can be realized , Realize data exchange under industrial fieldbus and industrial Ethernet , It is widely used .

utilize PLC, We can transfer the on-site information to the computer control center , In this way, computer control can be realized .

（4） Automatic control principle

The principle of automatic control is the core theory of Automation .

From the picture 1 Water level control , We can vaguely feel , The controlled quantity can be expressed by one or more differential equations , How to solve differential equations in automatic control technology has obviously become a key content .

Let's think about the relationship between logarithm and anti number . We use logarithm to multiply, divide and power 、 Square root becomes addition and subtraction and multiplication and division , After the calculation, reverse the transformation , You can get the answer . In the principle of automatic control , Change the differential equation into the complex field by using the integral transformation in the function of complex variable , Differential equations become algebraic equations . This kind of algebraic equation is called transfer function in automatic control technology . We solve the transfer function by algebraic equation , It's much easier , Then the inverse transformation returns to the real number field , Continue to solve and get the final solution .

In automatic control technology , Often no longer change back , Directly use the transfer function to perform analysis and solution .

As I said before PID equation , And the software that executes power monitoring in the computer , They can be solved by transfer function . even to the extent that , stay PLC In the internal module of , There's a special one PID Module and transfer function parsing module .

The principle of automatic control is that input parameters 、 Feedback parameters 、 Regulation control is connected with output control .

3. For high school students , What books should we read to understand Automation ？

We can see from the previous description , It is impossible to learn automation technology at the level of high school students , But if we only understand automation , It should be possible .

Let me introduce some books to the subject .

The first book ：《 A book to understand driverless 》, Edited by Yang Kuan and others , Published by chemical industry press .

The second book ：《 What is automation 》, Edited by Wang Hongwei , Published by Dalian University of Technology Press .

The third book ：《 Artificial intelligence : use AI Technology creates an intelligent future 》, China Science and Technology Press

The fourth book ：《 Introduction to Automation 》, The second edition , Written by Dai Xianzhong , Higher Education Press

I only have these four books , It feels good , Among them, the second and third books are worth promoting .

As for college textbooks , It is suggested that the subject should be exempted . For one thing, we have to take the college entrance examination ourselves , These textbooks are too deep , It is not recommended to read textbooks .