A hot blast furnace pressure equalization control method and system based on sliding mode and robust control

Abstract

The present invention discloses a hot blast stove pressure equalization control method and system based on sliding mode and robust control. The method comprises: creating a control model based on the operating parameters of the hot blast stove; the control model comprises a control quantity, a controlled quantity, a state quantity and an error term; creating a sliding surface and a switching function based on the tracking error of the state quantity; creating a control law and a Lyapunov function based on the control quantity and the state quantity, and introducing a robust weighted term u in the control law. s = ‑ηsgn(z), where η is a weighting coefficient and z is a sliding surface; the state quantity is driven to the sliding surface by the switching function, and the control quantity is solved by the control law; and the state quantity moving on the sliding surface and the obtained control quantity are substituted into the control model to output the controlled quantity. The present invention can effectively improve the large inertia problem existing in the original sliding mode control when performing the hot blast furnace equalizing pressure control, thereby improving the actual value of the equalizing pressure control and the steel quality of blast furnace steelmaking.

Description

Technical Field

[0001] The invention relates to the technical field of hot blast furnace control for steelmaking, and in particular to a hot blast furnace equalizing pressure control method and system based on sliding mode and robust control. Background Art

[0002] Hot blast stove is an important equipment in blast furnace steelmaking process, which is used to continuously provide high-temperature hot blast of not less than 1000℃ for blast furnace. In order to maintain the continuous high-temperature hot blast in the blast furnace, 3 to 4 staggered parallel hot blast stoves are used to alternately deliver high-temperature hot blast to the blast furnace in the actual steelmaking process.

[0003] The operating parameters of the hot blast stove generally include the dome temperature, flue gas oxygen content, main pipe pressure, etc. Accurately regulating the operating parameters is the key to ensuring that any hot blast stove can stably provide high-temperature hot blast to the blast furnace. The constant pressure in the hot blast stove is the key to ensuring that the adjustment effect of the relevant operating parameters can effectively act on the hot blast stove itself, and then act on the blast furnace steelmaking process.

[0004] Based on the actual working process of the hot blast stove, the existing control strategy for equalizing the pressure in the hot blast stove is mainly sliding mode control. The sliding mode control is a variable structure control strategy, which designs the sliding surface based on the dynamic characteristics expected by the control system, and sets the sliding mode control law to make the control system converge to the sliding surface, thereby making the control system move according to the state trajectory of the predetermined sliding mode; finally, the purpose of controlling the control system is achieved.

[0005] Since the sliding mode in the sliding mode control is independent of disturbances, the sliding mode has the advantages of simple implementation process and fast single response speed when controlling the normal operation of the hot blast stove and the pressure system during furnace change. But in fact, the overall structure and internal working environment of the hot blast stove are relatively complex, and there are often various interferences such as noise and fly ash. The interference will affect the actual control result of the sliding mode control, so that the entire control process when reaching the constant pressure state is longer, that is, there is a technical problem of large inertia of the equalizing pressure control system. At this time, there may be a situation where the control system has not yet maintained the hot blast stove in a constant pressure state in a certain working stage, and the hot blast stove has actually switched to the next working stage. As a result, the control process has no practical value and has an adverse effect on blast furnace steelmaking. Summary of the invention

[0006] The object of the present invention is to provide a hot blast stove equalizing pressure control method and system based on sliding mode and robust control, so as to solve the technical problem of large inertia existing in the hot blast stove equalizing pressure control process.

[0007] To achieve the above object, the present invention proposes the following technical solutions:

[0008] A hot blast furnace pressure equalization control method based on sliding mode and robust control, comprising:

[0009] Creating a control model based on the operating parameters of the hot blast stove; the control model includes a control variable, a controlled variable, a state variable and an error term;

[0010] Creating a sliding surface and a switching function based on the tracking error of the state quantity;

[0011] A control law and a Lyapunov function are created based on the control quantity and the state quantity, and a robust weighted term u is introduced into the control law. s = -ηsgn(z), where η is the weighting coefficient and z is the sliding surface;

[0012] The state quantity is driven to the sliding surface through the switching function, and the control quantity is solved through the control law; and the state quantity moving on the sliding surface and the obtained control quantity are substituted into the control model to output the controlled quantity.

[0013] Furthermore, the operating parameters of the hot blast stove include: cold air pipe pressure, cold air equalizing valve opening, flue gas pipe pressure and flue gas equalizing valve opening.

[0014] Furthermore, the creation of a control model based on the operating parameters of the hot blast stove includes:

[0015] Based on the dynamic characteristics of the hot air stove, the cold air duct pressure is determined as the controlled variable, and the opening of the cold air equalizing pressure valve is determined as the controlled variable;

[0016] A transfer function is established based on the dynamic characteristics, the control variable and the controlled variable. Among them, s is the complex frequency of the transfer function, K1 is the cold air pressure gain coefficient, K2 is the flue gas pressure gain coefficient, T1 is the cold air pipe pressure change time, and T2 is the flue gas pipe pressure change time;

[0017] The transfer function is transformed based on the model transformation to obtain the state space Among them, k is the time variable, x(k) is the state variable, u(k) is the control variable, and y(k) is the controlled variable; K3d(k) is the error term, where K3 is the dimension matrix, and d(k) is a nonlinear function representing the error.

[0018] Furthermore, the creating of the sliding surface and the switching function based on the tracking error of the state quantity includes:

[0019] Create sliding surface z = x(k)-x(k) d ; Wherein, x(k) is the state quantity, x(k) d is the expected value of x(k);

[0020] Creating a Switch Function

[0021] Furthermore, the control law is:

[0022] u=Fx(k)+u d +u s , where F is the state feedback gain, x(k) is the state quantity, u d is the feedforward control term;

[0023] Among them, x(k) d is the expected value of x(k).

[0024] Furthermore, creating a control law based on the control quantity and the state quantity also includes:

[0025] Setting A T P+Q T +PA+Q<0, where F=P -1 Q, P is a random constant diagonal matrix, and Q is the state feedback anti-diagonal gain.

[0026] Furthermore, the creating of the Lyapunov function includes:

[0027] Create a constructor V = z T Pz;

[0028] Substitute the error term and the control law into the constructor and derive them to obtain

[0029] Create LMI inequalities based on the derivatives of the constructor Where R = A T P+F T P+PA+PF.

[0030] A hot blast furnace pressure equalization control system based on sliding mode and robust control, comprising:

[0031] A model creation module, used to create a control model based on the operating parameters of the hot blast stove; the control model includes a control quantity, a controlled quantity, a state quantity and an error term;

[0032] A first parameter creation module, used for creating a sliding surface and a switching function based on a tracking error of the state quantity;

[0033] The second parameter creation module creates a control law and a Lyapunov function based on the control quantity and the state quantity, and introduces a robust weighted term u in the control law. s = -ηsgn(z), where η is the weighting coefficient and z is the sliding surface;

[0034] An execution module is used to drive the state quantity to the sliding surface through the switching function, solve the control quantity through the control law; and substitute the state quantity moving on the sliding surface and the obtained control quantity into the control model to output the controlled quantity.

[0035] Furthermore, the second parameter creation module includes:

[0036] The first LMI optimization module is used to perform LMI optimization processing on the created control law.

[0037] Furthermore, the second parameter creation module includes:

[0038] The second LMI optimization module is used to perform LMI optimization processing on the created Lyapunov function.

[0039] Beneficial effects:

[0040] It can be seen from the above technical solutions that the technical solution of the present invention provides a new hot blast stove pressure equalization control method to improve the defects existing in the existing hot blast stove pressure equalization control process.

[0041] The method comprises: first, creating a control model based on the operating parameters of the hot blast stove; the control model comprises a control quantity, a controlled quantity, a state quantity and an error term. Then, creating a sliding surface and a switching function based on the tracking error of the state quantity. Secondly, creating a control law and a Lyapunov function based on the control quantity and the state quantity, and introducing a robust weighted term u in the control law. s =-ηsgn(z), where η is the weighting coefficient and z is the sliding surface. Finally, the state quantity is driven to the sliding surface through the switching function, and the control quantity is solved through the control law; and the state quantity moving on the sliding surface and the obtained control quantity are substituted into the control model to output the controlled quantity.

[0042] From the above process, it can be concluded that the control method is based on the sliding mode control strategy to ensure that the entire pressure equalization control still maintains the advantages of a simple control process and a fast single response speed. At the same time, since in the specific control process, the control quantity will eventually converge to the control law, and the control quantity determines the output result of the controlled quantity, that is, the accuracy of the control result. However, since the sliding mode control strategy does not consider interference factors, it is contrary to the objective reality that there is interference during the actual operation of the hot blast furnace; therefore, the interference in actual conditions is bound to affect the accuracy of the control quantity obtained based on the pure sliding mode control law under the sliding mode control strategy. In order to improve this defect, the technical solution introduces a robust weighted term u related to the robust control strategy in the control law. s=-ηsgn(z). Since the robust control strategy can maintain good control performance within a certain range of fluctuations, the introduction of the robust weighted term can effectively resist interference, thereby improving control accuracy. This enables the hot blast furnace to reach the expected pressure balance state faster, eliminating the large inertia defect existing in the original single sliding mode control.

[0043] From the above analysis, it can be seen that this technical solution is based on the sliding mode control strategy and introduces a robust control strategy, so that the pressure equalization control process of the hot blast furnace has the advantages of simple control process, fast single response speed, and shorter total control time. Ultimately, it can also improve the steel quality of the entire blast furnace steelmaking.

[0044] It should be appreciated that all combinations of the foregoing concepts, as well as additional concepts described in greater detail below, may be considered to be part of the inventive subject matter of the present disclosure, provided such concepts are not mutually inconsistent.

[0045] The foregoing and other aspects, embodiments and features of the present invention can be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present invention, such as the features and / or beneficial effects of the exemplary embodiments, will be apparent from the following description or learned from the practice of the specific embodiments according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in various figures may be represented by the same reference numeral. For clarity, not every component is labeled in every figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings, in which:

[0047] Figure 1 It is a flow chart of the hot blast stove pressure equalization control method based on sliding mode and robust control described in this embodiment;

[0048] Figure 2 for Figure 1 A flow chart for creating the control model described in;

[0049] Figure 3 for Figure 1 A flow chart for creating the sliding surface and the switching function;

[0050] Figure 4 for Figure 1 Flowchart for creating the control law described in;

[0051] Figure 5 for Figure 1 Flowchart for the creation of the Lyapunov function described in . DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with ordinary skills in the field to which the present invention belongs.

[0053] The words "first", "second" and similar words used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular form of "a", "an" or "the" and other similar words do not indicate a quantitative limitation, but indicate the existence of at least one. "Include" or "comprise" and other similar words mean that the elements or objects appearing before "include" or "comprise" include the features, wholes, steps, operations, elements and / or components listed after "include" or "comprise", and do not exclude the existence or addition of one or more other features, wholes, steps, operations, elements, components and / or their collections. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0054] The existing hot blast furnace pressure equalization control is mostly based on a single sliding mode control. Therefore, the hot blast furnace pressure equalization control process has the advantages of simple control process and fast single response speed. However, the sliding mode control does not consider the control process of interference factors, which is inconsistent with the objective situation that there is obvious interference in the operation of the hot blast furnace. Therefore, in actual control, it has the defects of low single regulation accuracy and long total control time, thereby reducing the actual value of pressure equalization control. Therefore, the present invention aims to provide a hot blast furnace pressure equalization control method and system based on sliding mode and robust control, which is used to solve the large inertia defect when a single sliding mode control is currently used.

[0055] like Figure 1 As shown, the method includes:

[0056] Step S102: creating a control model based on the operating parameters of the hot blast stove; the control model includes a control variable, a controlled variable, a state variable and an error term.

[0057] In this step, the hot blast stove operating parameters used to create the control model specifically include: cold air pipe pressure, cold air equalizing valve opening, flue gas pipe pressure and flue gas equalizing valve opening.

[0058] The existing hot blast stove pressure equalization control focuses on the control of flue gas pressure or flue gas flow rate, while the working gas in the mixing chamber of the actual hot blast stove includes both high-temperature coal gas (i.e. flue gas) and air provided by the air cooler (i.e. cold air). Therefore, considering the effect of flue gas alone will cause deviations in the control process. Therefore, in this embodiment, parameters related to cold air and flue gas are simultaneously introduced as parameters for creating the control model.

[0059] The purpose of creating the control model is to obtain the corresponding state space. As an optional implementation method, Figure 2 The creation process of the control model includes:

[0060] Step S102.2: Based on the dynamic characteristics of the hot air stove, determine that the cold air duct pressure is the controlled variable, and the opening of the cold air equalizing pressure valve is the controlled variable.

[0061] At the same time, since the high-temperature coal gas is provided through the combustion chamber and the secondary combustion chamber in sequence, and the cold air is directly provided by the cold air blower connected to the outside air, the cold air pipe pressure is used as the control quantity, and the opening of the cold air equalizing pressure valve is used as the controlled quantity, which is more conducive to simplifying the entire equalizing pressure control process and saving control time.

[0062] Step S102.4: Establish a transfer function based on the dynamic characteristics and the control quantity and the controlled quantity. Wherein, s is the complex frequency of the transfer function, K1 is the cold air pressure gain coefficient, K2 is the flue gas pressure gain coefficient, T1 is the cold air duct pressure change time, and T2 is the flue gas duct pressure change time.

[0063] In this step, the cold air pressure gain coefficient is related to the cold air pipe pressure, the flue gas pressure gain coefficient is related to the flue gas pipe pressure, the cold air pipe pressure change time is related to the cold air equalizing pressure valve opening, and the flue gas equalizing pressure valve opening.

[0064] Step S102.6: Based on the model conversion, the transfer function is converted to obtain a state space Among them, k is the time variable, x(k) is the state variable, u(k) is the control variable, and y(k) is the controlled variable; K3d(k) is the error term, where K3 is the dimension matrix, and d(k) is a nonlinear function representing the error.

[0065] The error term in this step is used to introduce unknown interference so that the state space is closer to the time situation of the combustion furnace. The dimensional matrix K3 expands the interference situation represented by the nonlinear function d(k).

[0066] Step S104: creating a sliding surface and a switching function based on the tracking error of the state quantity.

[0067] As a specific implementation method, Figure 3 As shown, the process of creating the sliding surface and the switching function includes:

[0068] Step S104.2: Create a sliding surface z=x(k)-x(k) d ; Wherein, x(k) is the state quantity, x(k) d is the expected value of x(k).

[0069] Step S104.4: Create a switching function

[0070] Step S106: Create a control law and a Lyapunov function based on the control quantity and the state quantity, and introduce a robust weighted term u into the control law. s =-ηsgn(z), where η is the weighting coefficient and z is the sliding surface.

[0071] The robust weighted term in this step is used to improve the influence of interference factors on the accuracy of sliding mode control during the actual operation of the hot blast stove, thereby improving the large inertia technical problem when using a single sliding mode control.

[0072] As a specific implementation method, Figure 4 As shown, the control law created is:

[0073] u=Fx(k)+u d +u s , where F is the state feedback gain, x(k) is the state quantity, u d is the feedforward control term;

[0074] Among them, x(k) d is the expected value of x(k).

[0075] It can be seen that the control law includes both items related to sliding mode control and items related to robust control. In actual control, the control law is the convergence result of the control quantity, and the control quantity determines the output result of the controlled quantity. Therefore, the sliding mode control strategy and the robust control strategy are introduced into the control law at the same time, so that the control process has the advantages of simple control process and fast single response speed of sliding mode control, and also has the advantage of good control performance under certain fluctuation conditions of robust control.

[0076] For the robust weighting term u s =-ηsgn(z), the specific function of sgn(z) is:

[0077]

[0078] The weighting coefficient η is a manual parameter. The purpose of the robust weighting term in this embodiment is to introduce robust control into the sliding mode control to improve the influence of interference. Therefore, setting it as a manual parameter can avoid introducing new parameters to complicate the control method and reduce the advantage of the original simple control process. On the other hand, it can also avoid introducing new interference that goes against the original intention of introducing robust control, resulting in the control effect being lower than that of single sliding mode control.

[0079] In a specific implementation, in order to comply with the control distance, the adjustment of the weighting coefficient η is based on the empirical adjustment related to the interference during actual operation, that is, the weighting coefficient η is an adjustable empirical parameter.

[0080] As a preferred embodiment, Figure 4 As shown, the control law creation process also includes:

[0081] Step S106.2.2, set A T P+Q T +PA+Q<0, where F=P -1 Q, P is a random constant diagonal matrix, and Q is the state feedback anti-diagonal gain.

[0082] From the above process and analysis, it can be seen that the method is based on sliding mode control, so there is chattering, and the control law is the final convergence result of the control amount. Therefore, in this embodiment, LMI optimization is introduced into the control law through step S106.2.2 to improve the chattering phenomenon existing in the method and further improve the control accuracy. At the same time, since the overall calculation amount of the LMI optimization method is small, it is easier to implement and can also further improve the large inertia defect in the control process.

[0083] As a preferred embodiment, Figure 5 , the creation process of the Lyapunov function includes:

[0084] Step S106.4.2: Create a constructor V=z T Pz.

[0085] Step S106.4.4, substitute the error term and the control law into the constructor, and derive them to obtain

[0086] Step S106.4.6: Create an LMI inequality based on the derivative of the constructor Where R = A T P+F T P+PA+PF.

[0087] From step S106.4.2 to step S106.4.6, it can be seen that LMI optimization is also introduced into the Lyapunov function used to verify the stability of the method, so as to ensure consistency between the stability verification part and the control strategy part.

[0088] Step S108, driving the state quantity to the sliding surface through the switching function, solving the control quantity through the control law; and substituting the state quantity moving on the sliding surface and the obtained control quantity into the control model to output the controlled quantity.

[0089] It can be seen from the above steps that the method is based on the sliding mode control strategy and introduces a robust control strategy, so that the pressure equalization control process of the hot blast stove has the advantages of simple control process, fast single response speed and shorter total control time. Ultimately, the steel quality of the entire blast furnace steelmaking can be improved.

[0090] The above method process can be run in a processor, or can also be stored in a memory (or computer-readable medium), which includes permanent and non-permanent, removable and non-removable media. Information storage can be achieved by any method or technology. Information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include temporary computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0091] These computer programs can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps of the functions specified in one or more blocks can be implemented by different modules corresponding to different steps.

[0092] This embodiment also provides a hot blast furnace pressure equalization control system based on sliding mode and robust control, and the system is built based on the method. It includes:

[0093] A model creation module, used to create a control model based on the operating parameters of the hot blast stove; the control model includes a control quantity, a controlled quantity, a state quantity and an error term;

[0094] A first parameter creation module, used for creating a sliding surface and a switching function based on a tracking error of the state quantity;

[0095] The second parameter creation module creates a control law and a Lyapunov function based on the control quantity and the state quantity, and introduces a robust weighted term u in the control law. s = -ηsgn(z), where η is the weighting coefficient and z is the sliding surface;

[0096] An execution module is used to drive the state quantity to the sliding surface through the switching function, solve the control quantity through the control law; and substitute the state quantity moving on the sliding surface and the obtained control quantity into the control model to output the controlled quantity.

[0097] From the above functional modules, it can be seen that the system adopts sliding mode control as the main strategy, and from the second parameter creation module, it can be seen that the robust weighted term u is introduced into the control law. s =-ηsgn(z), so the system will also include a robust control strategy. Therefore, in specific implementation, the system has the advantages of simple control process and fast single response speed of sliding mode control, and also has the advantage of good control performance under certain fluctuations during robust control. Ultimately, the quality of steel produced by the entire blast furnace steelmaking can be improved.

[0098] In a specific implementation, in order to improve the chattering phenomenon in the sliding mode control process, the second parameter creation module includes: a first LMI optimization module, which is used to perform LMI optimization processing on the created control law.

[0099] As a further optimization method, the second parameter creation module includes: a second LMI optimization module, which is used to perform LMI optimization processing on the created Lyapunov function.

[0100] Specifically, the model creation module includes:

[0101] The parameter acquisition unit is used to acquire the operating parameters of the hot blast stove and determine the control quantity and the controlled quantity based on the dynamic characteristics of the hot blast stove. In this embodiment, the operating parameters include: cold air duct pressure, cold air equalizing valve opening, flue gas duct pressure and flue gas equalizing valve opening; the control quantity is the cold air duct pressure, and the controlled quantity is the cold air equalizing valve opening.

[0102] A transfer function creation unit, used to establish a transfer function based on the dynamic characteristics and the control quantity and the controlled quantity

[0103] A state space creation unit is used to convert the transfer function based on the model conversion to obtain a state space Where K3d(k) is the error term, K3 is a dimension matrix, and d(k) is a nonlinear function representing the error.

[0104] The first parameter creation module includes:

[0105] Sliding surface creation unit, used to create sliding surface z = x(k)-x(k) d ; Wherein, x(k) is the state quantity, x(k) d is the expected value of x(k).

[0106] Switching function creation unit, used to create switching functions

[0107] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A hot blast stove pressure equalization control method based on sliding mode and robust control, characterized in that: include: Creating a control model based on the operating parameters of the hot blast stove; the control model includes a control variable, a controlled variable, a state variable and an error term; The operating parameters include: cold air pipe pressure, cold air equalizing valve opening, flue gas pipe pressure and flue gas equalizing valve opening; in, Firstly, based on the dynamic characteristics of the hot air stove, the cold air pipe pressure is determined as the control variable, and the opening of the cold air equalizing pressure valve is determined as the controlled variable; Secondly, a transfer function is established based on the dynamic characteristics and the control quantity and the controlled quantity. Among them, s is the complex frequency of the transfer function, K1 is the cold air pressure gain coefficient, K2 is the flue gas pressure gain coefficient, T1 is the cold air pipe pressure change time, and T2 is the flue gas pipe pressure change time; Then, the transfer function is transformed based on the model transformation to obtain the state space Where k is the time variable, x(k) is the state variable, u(k) is the control variable, and y(k) is the controlled variable; K3d(k) is the error term, where K3 is the dimension matrix, and d(k) is a nonlinear function representing the error; Creating a sliding surface and a switching function based on the tracking error of the state quantity; The process includes: first, creating a sliding surface z = x(k)-x(k) d ; Wherein, x(k) is the state quantity, x(k) d is the expected value of x(k); secondly, create a switching function A control law and a Lyapunov function are created based on the control quantity and the state quantity, and a robust weighted term u is introduced into the control law. s = -ηsgn(z), where η is the weighting coefficient and z is the sliding surface; Wherein, the control law is: u=Fx(k)+u d +u s ; Where F is the state feedback gain, x(k) is the state quantity, u d is the feedforward control term; Among them, x(k) d is the expected value of x(k); The state quantity is driven to the sliding surface through the switching function, and the control quantity is solved through the control law; and the state quantity moving on the sliding surface and the obtained control quantity are substituted into the control model to output the controlled quantity.

2. The hot blast stove pressure equalization control method based on sliding mode and robust control according to claim 1 is characterized in that: Creating a control law based on the control quantity and the state quantity also includes: Setting A T P+Q T +PA+Q<0, where F=P -1 Q, P is a random constant diagonal matrix, and Q is the state feedback anti-diagonal gain.

3. The hot blast stove pressure equalization control method based on sliding mode and robust control according to claim 2 is characterized in that: The creating of the Lyapunov function comprises: Create a constructor V = z T Pz; Substitute the error term and the control law into the constructor and derive them to obtain Create LMI inequalities based on the derivatives of the constructor Where R = A T P+F T P+PA+PF.

4. A hot blast stove pressure equalization control system based on sliding mode and robust control, characterized in that: The method for implementing any one of claims 1 to 3 comprises: A model creation module, used to create a control model based on the operating parameters of the hot blast stove; the control model includes a control quantity, a controlled quantity, a state quantity and an error term; A first parameter creation module, used for creating a sliding surface and a switching function based on a tracking error of the state quantity; The second parameter creation module creates a control law and a Lyapunov function based on the control quantity and the state quantity, and introduces a robust weighted term u in the control law. s = -ηsgn(z), where η is the weighting coefficient and z is the sliding surface; An execution module is used to drive the state quantity to the sliding surface through the switching function, solve the control quantity through the control law; and substitute the state quantity moving on the sliding surface and the obtained control quantity into the control model to output the controlled quantity.

5. The hot blast stove pressure equalization control system based on sliding mode and robust control according to claim 4, characterized in that: The second parameter creation module includes: The first LMI optimization module is used to perform LMI optimization processing on the created control law.

6. The hot blast stove pressure equalization control system based on sliding mode and robust control according to claim 4, characterized in that: The second parameter creation module includes: The second LMI optimization module is used to perform LMI optimization processing on the created Lyapunov function.

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