CN113867131B - EGR control method, device and electronic equipment - Google Patents

Abstract

The present application discloses a method, device and electronic device for EGR control, the method comprising observing the current opening value of the EGR valve, the first-order derivative of the current opening of the EGR valve and the disturbance through an expansion observer (ESO), and calculating the duty cycle of the EGR valve according to the current opening value of the EGR valve, the first-order derivative of the current opening of the EGR valve and the disturbance, and then controlling the opening of the EGR valve according to the duty cycle. Based on the above method, the system disturbance is directly estimated through the ESO, so that when calculating the duty cycle of the EGR valve, the size of the system disturbance can be considered, thereby making the actual opening value of the EGR valve closer to the target opening value of the EGR valve, thereby reducing the adjustment time of the control system and improving the responsiveness of the EGR system.

Description

EGR control method, device and electronic equipment

Technical Field

The present application relates to the field of engine control technology, and in particular to an EGR control method, device and electronic equipment.

Background technique

In order to meet the increasingly stringent engine exhaust emission requirements, an exhaust gas recirculation (EGR) system is usually installed in conjunction with the engine. EGR returns part of the exhaust gas discharged by the engine to the intake pipe, and then re-enters the cylinder together with the fresh mixed gas, reducing the oxygen content in the intake air, thereby reducing the combustion temperature and reducing emission pollution. However, during the exhaust gas recirculation process, if too much exhaust gas is recycled, the oxygen content entering the cylinder will not meet the specified value, thereby affecting the engine power. Therefore, it is very important to control the EGR duty cycle according to the actual working conditions of the engine, and then control the opening of the EGR valve to ensure that the engine can reduce exhaust emissions while being used normally.

In order to solve the above problems, the traditional solution uses a PID controller to achieve closed-loop control of the EGR system. During the PID control process, the control is performed according to the proportion (P), integral (I) and differential (D) of the difference. Specifically, the existing method mainly calculates the difference between the EGR valve opening reference value and the current EGR valve opening value, and then inputs the difference into the PID controller to obtain the output duty cycle and control the EGR system.

However, the gains of P, I and D in PID control are difficult to adjust and cannot be continuously updated based on feedback. A lot of time is required for continuous trial and error. Therefore, if PID control is used, there will be a problem of delayed responsiveness of the EGR system.

Summary of the invention

The present application provides an EGR control method, device and electronic device, which directly estimates the system disturbance through ESO, so that the size of the system disturbance can be taken into account when calculating the duty cycle of the EGR valve, thereby making the actual opening value of the EGR valve closer to the target opening value of the EGR valve, thereby reducing the adjustment time of the control system and improving the responsiveness of the EGR system.

In a first aspect, the present application provides a method for EGR control, the method comprising: calculating the duty cycle of the EGR valve based on the current opening value of the EGR valve observed by an expansion observer ESO, the first-order derivative of the current opening of the EGR valve, and the disturbance amount, and then controlling the opening of the EGR valve based on the duty cycle.

In the above method, the system disturbance is directly estimated through ESO, so that the size of the system disturbance can be taken into account when calculating the duty cycle of the EGR valve, thereby making the actual opening value of the EGR valve closer to the target opening value of the EGR valve, thereby reducing the adjustment time of the control system and improving the responsiveness of the EGR system.

In a possible design, before observing the current opening value of the EGR valve, the first-order derivative of the current opening of the EGR valve and the disturbance from the expanded observer ESO, it also includes: establishing a second-order differential equation of the EGR system, and constructing an extended state observer ESO based on the second-order differential equation.

In one possible design, the second-order differential equation of the EGR system is established, which is obtained by the following formula:

in, is the second-order derivative of the valve plate rotation angle, /> J＝(J _g +n ² *J _m ), u is the duty cycle of the H-bridge circuit,/> is the first-order derivative of the valve disc rotation angle, _ks is the stiffness coefficient of the return spring, θ is the valve disc rotation angle, n is the transmission gear ratio, _Vb is the battery voltage, _km is the relationship coefficient between the electromotive force and the angular velocity, R is the resistance, _kb is the relationship coefficient between the current and the electromagnetic torque, _T0 is the initial torque of the return spring in the static position, _Tf is the friction force, and _Tα is the airflow impact torque.

In one possible design, an extended state observer (ESO) is constructed, including:

According to the second-order differential equation, the expanded state equation of the EGR system is obtained:

in, x ₁ =θ,/> x ₃ =f,/>

Based on the above extended state equation, the extended state observer ESO is obtained:

Among them, the estimated value of the state quantity x is The estimated value of output y is/> Observer gain matrix The ESO gain matrix L makes the characteristic roots of the (A-LC) matrix in the left half of the complex plane.

In one possible design, the duty cycle of the EGR valve is calculated, including: after calculating the first control quantity based on the EGR valve opening reference value and the current opening value of the EGR valve, calculating the second control quantity based on the first control quantity and the first-order derivative of the current opening of the EGR valve, and then calculating the duty cycle of the EGR valve based on the second control quantity, the current opening value of the EGR valve and the disturbance quantity.

In a possible design, the second control amount is calculated, specifically by the following formula:

in, is the second control variable, K _p (θ _setting - θ) + K _d (θ _setting - θ) is the first control variable, θ _setting is the EGR valve opening reference value, θ is the current opening value of the EGR valve, / > is the first-order derivative of the current opening of the EGR valve, />

In one possible design, the duty cycle of the EGR valve is calculated using the following formula:

Wherein, u is the duty cycle of the EGR valve, is the second control variable, θ is the current opening value of the EGR valve, f is the disturbance value,

In a second aspect, the present application provides an EGR control device, the device comprising:

The observation module obtains the current opening value of the EGR valve, the first-order derivative of the current opening value of the EGR valve, and the disturbance through the expansion observer ESO;

a calculation module, calculating a duty cycle of the EGR valve according to a current opening value of the EGR valve, a first-order derivative of the current opening value of the EGR valve, and the disturbance amount;

A control module controls the opening of the EGR valve according to the duty cycle.

In a possible design, before the observation module, a second-order differential equation of the EGR system is also established; based on the second-order differential equation, an extended state observer ESO is constructed. .

In a possible design, before the observation module, it is also used to establish the second-order differential equation of the EGR system, which is specifically obtained by the following formula:

in, is the second-order derivative of the valve plate rotation angle, /> J＝(J _g +n ² *J _m ), u is the duty cycle of the H-bridge circuit,/> is the first-order derivative of the valve disc rotation angle, _ks is the stiffness coefficient of the return spring, θ is the valve disc rotation angle, n is the transmission gear ratio, _Vb is the battery voltage, _km is the relationship coefficient between the electromotive force and the angular velocity, R is the resistance, _kb is the relationship coefficient between the current and the electromagnetic torque, _T0 is the initial torque of the return spring in the static position, _Tf is the friction force, and _Tα is the airflow impact torque.

In a possible design, before the observation module, it is also used to construct an extended state observer ESO based on the second-order differential equation, including:

According to the second-order differential equation, the expanded state equation of the EGR system is obtained:

in, x ₁ =θ,/> x ₃ =f,/>

According to the extended state equation, the extended state observer ESO is obtained:

Among them, the estimated value of the state quantity x is The estimated value of output y is/> Observer gain matrix The ESO gain matrix L makes the characteristic roots of the (A-LC) matrix in the left half of the complex plane.

In one possible design, the calculation module is specifically used to obtain a first control quantity based on an EGR valve opening reference value and a current opening value of the EGR valve; calculate a second control quantity based on the first control quantity and a first-order derivative of the current opening of the EGR valve; and calculate a duty cycle of the EGR valve based on the second control quantity, the current opening value of the EGR valve and the disturbance quantity.

In a possible design, the calculation module is specifically used to calculate the second control amount, which is obtained by the following formula:

in, is the second control variable, K _p (θ _setting - θ) + K _d (θ _setting - θ) is the first control variable, θ _setting is the EGR valve opening reference value, θ is the current opening value of the EGR valve, / > is the first-order derivative of the current opening of the EGR valve, />

In a possible design, the calculation module is specifically used to calculate the duty cycle of the EGR valve, which is obtained by the following formula:

Wherein, u is the duty cycle of the EGR valve, is the second control variable, θ is the current opening value of the EGR valve, f is the disturbance value,

In a third aspect, the present application provides an electronic device, the electronic device comprising:

Memory, used to store computer programs;

The processor is used to implement the above-mentioned method steps for detecting an object with abnormal motion state when executing the computer program stored in the memory.

In a fourth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method steps for detecting an object with an abnormal motion state described above are implemented.

For each aspect from the second to the fourth aspect and the technical effects that may be achieved by each aspect, please refer to the above description of the technical effects that can be achieved by the first aspect or various possible schemes in the first aspect, and no further details will be given here.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a flow chart of an EGR control method provided by the present application;

FIG2 is a flow chart of a method for constructing an ESO provided by the present application;

FIG3 is a schematic diagram of a possible application scenario of EGR control provided by the present application;

FIG4 is a schematic diagram of an EGR control device provided by the present application;

FIG5 is a schematic diagram of the structure of an electronic device provided by the present application.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. The specific operating methods in the method embodiments can also be applied to device embodiments or system embodiments. It should be noted that in the description of the present application, "multiple" is understood as "at least two". "And/or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone. A is connected to B, which can represent: A is directly connected to B and A is connected to B through C. In addition, in the description of the present application, words such as "first" and "second" are only used to distinguish the purpose of description, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order.

In order to facilitate those skilled in the art to better understand the content of this application, the following is an explanation of the relevant terms involved in this application:

1. EGR: EGR is an important component in the engine system. It introduces exhaust gas into the intake pipe, reduces the oxygen content and combustion temperature in the intake air, and thus reduces NOx emissions.

2. PID control: A common control method in classical control theory, including proportional link, integral link, and differential link, to achieve closed-loop control of the system. PID mainly adjusts the output based on the deviation between the EGR opening set value and the actual EGR opening value.

The method provided in the embodiments of the present application is further described in detail below in conjunction with the accompanying drawings.

Referring to FIG. 1 , an embodiment of the present application provides a method for EGR control, and the specific process is as follows:

Step 101: obtaining the current opening value of the EGR valve, the first-order derivative of the current opening value of the EGR valve, and the disturbance through observation by an expanded observer ESO;

In an embodiment of the present application, ESO is constructed based on the second-order differential equation of the EGR system. Through ESO, not only the current opening value of the EGR valve in the EGR system and the first-order derivative of the current opening of the EGR valve can be observed, but also the disturbance that cannot be directly obtained from the EGR system can be observed.

Step 102: Calculate the duty cycle of the EGR valve according to the current opening value of the EGR valve, the first-order derivative of the current opening of the EGR valve and the disturbance amount;

In the embodiment of the present application, in the process of calculating the duty cycle of the EGR valve, not only the current opening value of the EGR valve and the first-order derivative of the current opening of the EGR valve are considered, but also the disturbance amount of the EGR system is considered, so that the calculated EGR valve opening value is closer to the target opening value actually required by the EGR valve.

Step 103: Controlling the opening of the EGR valve according to the duty cycle.

In an embodiment of the present application, a specific method for controlling the opening of the EGR valve according to the duty cycle of the EGR valve is as follows: according to the duty cycle of the EGR valve, the size of the EGR valve opening is adjusted, thereby controlling the opening of the EGR valve, thereby improving the responsiveness of the EGR control system.

Based on an EGR control method provided in an embodiment of the present application, the ESO is used to estimate the system disturbance and compensate the system disturbance to the input end, so that when calculating the duty cycle of the EGR valve, the size of the system disturbance can also be considered, thereby making the calculated EGR valve opening value closer to the target opening value of the EGR valve, thereby improving the responsiveness of the EGR control system.

In the above control method, the disturbance amount of the EGR system can be obtained through ESO. As shown in FIG2 , the method flow for constructing ESO includes the following steps:

Step 201: Establishing a second-order differential equation of the EGR system;

First, model the DC motor:

In formula 1, _Vm is the input voltage of the DC motor, i is the current in the circuit, R is the resistance, _Em is the electromotive force generated by the rotation of the DC motor, _km is the coefficient of the relationship between _the electromotive force and the angular velocity, _wm is the angular velocity of the DC motor, is the angular velocity of the DC motor, that is, /> is the first-order derivative of position.

Modeling the DC motor torque relationship:

In formula 2, _Tm is the electromagnetic torque output by the DC motor, _TL is the load torque of the DC motor, _Jm is the moment of inertia of the DC motor rotor, is the angular acceleration of the DC motor, that is, /> is the second-order derivative of position.

Furthermore, in Formula 2, T _m is proportional to the current: T _m =i*k _b , where k _b is the coefficient of the relationship between the current and the electromagnetic torque.

For the H-bridge circuit, if the duty cycle is u, the corresponding formula is as follows:

V _m =u*V _b

In Formula 3, _Vb is the battery voltage.

Considering the internal rotating structure of the EGR valve, the transmission gear ratio corresponds to the following formula:

In Formula 4, n is the transmission gear ratio, and _Tg is the torque converted to the EGR valve plate shaft.

Furthermore, the return spring inside the EGR valve is also considered, and the spring force is modeled in the default fully open state:

T _s = k _s *θ + T ₀ (Formula 5)

In Formula 5, _Ts is the spring force of the return spring in the fully open state, _ks is the stiffness coefficient of the return spring, θ is the valve disc rotation angle, and _T0 is the initial torque of the return spring in the static position.

Furthermore, on the basis of taking into account the spring force, factors such as airflow impact and friction are also considered, and the following formula is established with the EGR valve plate as the object:

In Formula 6, _Tf is the friction force, and _Tα is the airflow impact torque.

In the embodiment of the present application, the following formula can be obtained by combining the above formulas 1 to 6:

The above formula can be further simplified:

For Formula 7, let (J _g +n ² *J _m ) = J, Then the second-order differential equation of the EGR system can be obtained:

That is, Formula 8 is a second-order differential equation established by taking the H-bridge type EGR system as an example.

Step 202: Based on the second-order differential equation, construct an extended state observer ESO.

In the embodiment of the present application, based on Formula 8, the expansion state equation of the EGR system can be inferred:

In formula 9, x ₁ =θ,/> x ₃ =f,/>

According to formula 9, the mathematical model of the extended state observer ESO is obtained:

Among them, the estimated value of the state quantity x is The estimated value of output y is/> Observer gain matrix The ESO gain matrix L makes the characteristic roots of the (A-LC) matrix in the left half of the complex plane.

Based on the above method, the second-order differential equation of the EGR system is first constructed, and then the ESO is constructed based on the constructed second-order differential equation.

Furthermore, the disturbance is obtained through ESO observation, and the duty cycle of the EGR valve is calculated according to the current opening value of the EGR valve, the first-order derivative of the current opening of the EGR valve and the disturbance. The specific calculation method is as follows:

The difference between the EGR valve opening reference value and the current EGR valve opening value is input into the proportional controller to calculate the first control amount. The specific calculation formula is:

K _p (θ _setting - θ) + K _d (θ _setting - θ) (Formula 11)

In Formula 11, K _p (θ _setting −θ) + K _d (θ _setting −θ) is the first control variable, θ _setting is the EGR valve opening reference value, and θ is the current opening value of the EGR valve.

Combined with formula 11, the second control amount is calculated according to the first-order derivative of the current opening of the EGR valve. The specific calculation formula is:

In formula 12, is the first-order derivative of the current opening of the EGR valve, />

Based on formula 12, considering the disturbance amount, the duty cycle of the EGR valve is calculated. The specific calculation formula is:

In Formula 13, u is the duty cycle of the EGR valve.

By the above method, the duty cycle of the EGR valve is calculated, and the EGR valve duty cycle further considers the disturbance amount of the EGR system, so that the calculated duty cycle of the EGR valve is closer to the target duty cycle actually required by the EGR valve.

Finally, the opening of the EGR valve is controlled based on the calculated duty ratio of the EGR valve.

The embodiment of the present application is based on the above method and directly estimates the system disturbance through ESO, so that the size of the system disturbance can be taken into account when calculating the duty cycle of the EGR valve, thereby making the actual opening value of the EGR valve closer to the target opening value of the EGR valve, thereby reducing the adjustment time of the control system and improving the responsiveness of the system.

In addition, since most of the parameters in the ERG control method are system inherent parameters and can be directly obtained, the calibration workload can be reduced.

Furthermore, in order to explain in more detail an EGR control method provided by the present application, the method provided by the present application is described in detail below through a specific application scenario.

As shown in FIG. 3 , a schematic diagram of a possible application scenario based on the above-mentioned EGR control method is also provided in an embodiment of the present application.

In FIG3 , the difference between the EGR valve opening reference value (position setting value) _θsetting and the EGR valve current opening value (position actual value) θ is input into the proportional controller to obtain the first control amount _Kp ( _θsetting -θ)+ _Kd ( _θsetting -θ).

In the ESO of FIG3 , the current opening value x ₁ of the EGR valve, the first-order derivative x ₂ of the current opening value of the EGR valve, and the disturbance f are obtained.

According to the first control amount _Kp ( _θsetting -θ)+ _Kd ( _θsetting -θ), The first-order derivative x ₂ of the current opening of the EGR valve is used to calculate the second control quantity/>

Combined with the second control amount The stiffness coefficient of the return spring k _s , the current opening value of the EGR valve x ₁ , the disturbance f, /> By/> The duty cycle u of the EGR valve can be obtained by calculating the formula.

Finally, according to the calculated duty cycle of the EGR valve, the opening size of the EGR valve of the EGR system is adjusted.

In the above process, the disturbance amount f for calculating the EGR valve opening is obtained through the extended state controller ESO. The specific method of constructing the extended state controller ESO can refer to the method flow shown in FIG. 2 .

Based on the above EGR control method, the system disturbance is directly estimated through ESO, so that the size of the system disturbance can be taken into account when calculating the duty cycle of the EGR valve, thereby making the actual opening value of the EGR valve closer to the target opening value of the EGR valve, thereby reducing the adjustment time of the control system and improving the responsiveness of the EGR system.

In addition, since most of the parameters in the ERG control method are system inherent parameters and can be directly obtained, the calibration workload can be reduced.

Based on the same inventive concept, the present application also provides an EGR control device, which directly estimates the system disturbance through ESO, so that when calculating the duty cycle of the EGR valve, the size of the system disturbance can be considered, thereby making the actual opening value of the EGR valve closer to the target opening value of the EGR valve, thereby reducing the adjustment time of the control system and improving the responsiveness of the EGR system. Referring to Figure 4, the device includes:

An observation module 401 obtains the current opening value of the EGR valve, the first-order derivative of the current opening value of the EGR valve, and the disturbance through an expanded observer ESO;

A calculation module 402 calculates a duty cycle of the EGR valve according to the current opening value of the EGR valve, the first-order derivative of the current opening value of the EGR valve and the disturbance amount;

The control module 403 controls the opening of the EGR valve according to the duty cycle.

In a possible design, before the observation module 401, it is also used to establish a second-order differential equation of the EGR system; based on the second-order differential equation, an extended state observer ESO is constructed.

In a possible design, before the observation module 401, a second-order differential equation of the EGR system is also established, which is specifically obtained by the following formula:

in, is the second-order derivative of the valve plate rotation angle, /> J＝(J _g +n ² *J _m ), u is the duty cycle of the H-bridge circuit,/> is the first-order derivative of the valve disc rotation angle, _ks is the stiffness coefficient of the return spring, θ is the valve disc rotation angle, n is the transmission gear ratio, _Vb is the battery voltage, _km is the relationship coefficient between the electromotive force and the angular velocity, R is the resistance, _kb is the relationship coefficient between the current and the electromagnetic torque, _T0 is the initial torque of the return spring in the static position, _Tf is the friction force, and _Tα is the airflow impact torque.

In a possible design, before the observation module 401, it is also used to construct an extended state observer ESO based on the second-order differential equation, including:

According to the second-order differential equation, the expanded state equation of the EGR system is obtained:

in, x ₁ =θ,/> x ₃ =f,/>

According to the extended state equation, the extended state observer ESO is obtained:

Among them, the estimated value of the state quantity x is The estimated value of output y is/> Observer gain matrix The ESO gain matrix L makes the characteristic roots of the (A-LC) matrix in the left half of the complex plane.

In one possible design, the calculation module 402 is specifically used to obtain a first control quantity based on an EGR valve opening reference value and a current opening value of the EGR valve; calculate a second control quantity based on the first control quantity and a first-order derivative of the current opening of the EGR valve; and calculate a duty cycle of the EGR valve based on the second control quantity, the current opening value of the EGR valve and the disturbance quantity.

In a possible design, the calculation module 402 is specifically used to calculate the second control amount, which is obtained by the following formula:

in, is the second control variable, K _p (θ _setting - θ) + K _d (θ _setting - θ) is the first control variable, θ _setting is the EGR valve opening reference value, θ is the current opening value of the EGR valve, / > is the first-order derivative of the current opening of the EGR valve, />

In a possible design, the calculation module 402 is specifically used to calculate the duty cycle of the EGR valve, which is obtained by the following formula:

Wherein, u is the duty cycle of the EGR valve, is the second control variable, θ is the current opening value of the EGR valve, f is the disturbance variable, />

Based on the above device, the system disturbance is directly estimated through ESO, so that the size of the system disturbance can be taken into account when calculating the duty cycle of the EGR valve, thereby making the actual opening value of the EGR valve closer to the target opening value of the EGR valve, thereby reducing the adjustment time of the control system and improving the responsiveness of the EGR system.

Based on the same inventive concept, an electronic device is also provided in an embodiment of the present application, and the electronic device can realize the functions of the aforementioned EGR control device. Referring to FIG. 5 , the electronic device includes:

At least one processor 501, and a memory 502 connected to at least one processor 501. The specific connection medium between the processor 501 and the memory 502 is not limited in the embodiment of the present application. FIG. 5 takes the connection between the processor 501 and the memory 502 via the bus 500 as an example. The bus 500 is represented by a bold line in FIG. 5, and the connection between other components is only for schematic illustration and is not intended to be limiting. The bus 500 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one bold line is used in FIG. 5, but it does not mean that there is only one bus or one type of bus. Alternatively, the processor 501 can also be called a controller, and there is no restriction on the name.

In the embodiment of the present application, the memory 502 stores instructions that can be executed by at least one processor 501. The at least one processor 501 can execute the EGR control method discussed above by executing the instructions stored in the memory 502. The processor 501 can implement the functions of each module in the device shown in FIG5.

Among them, the processor 501 is the control center of the device, and can use various interfaces and lines to connect the various parts of the entire control device. By running or executing instructions stored in the memory 502 and calling data stored in the memory 502, the various functions of the device and process data, the device can be monitored as a whole.

In one possible design, the processor 501 may include one or more processing units, and the processor 501 may integrate an application processor and a modem processor, wherein the application processor mainly processes an operating system, a user interface, and application programs, and the modem processor mainly processes wireless communications. It is understandable that the modem processor may not be integrated into the processor 501. In some embodiments, the processor 501 and the memory 502 may be implemented on the same chip, and in some embodiments, they may also be implemented separately on separate chips.

The processor 501 may be a general-purpose processor, such as a central processing unit (CPU), a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of the present application. A general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the EGR control method disclosed in the embodiments of the present application may be directly embodied as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

The memory 502 is a non-volatile computer-readable storage medium that can be used to store non-volatile software programs, non-volatile computer executable programs and modules. The memory 502 may include at least one type of storage medium, such as a flash memory, a hard disk, a multimedia card, a card-type memory, a random access memory (Random Access Memory, RAM), a static random access memory (Static Random Access Memory, SRAM), a programmable read-only memory (Programmable Read Only Memory, PROM), a read-only memory (Read Only Memory, ROM), an electrically erasable programmable read-only memory (Electrically Erasable Programmable Read-Only Memory, EEPROM), a magnetic memory, a disk, an optical disk, etc. The memory 502 is any other medium that can be used to carry or store a desired program code in the form of an instruction or data structure and can be accessed by a computer, but is not limited thereto. The memory 502 in the embodiment of the present application can also be a circuit or any other device that can realize a storage function, for storing program instructions and/or data.

By designing and programming the processor 501, the code corresponding to the EGR control method introduced in the above embodiment can be fixed into the chip, so that the chip can execute the steps of the EGR control method of the embodiment shown in Figure 1 when running. How to design and program the processor 501 is a technology well known to those skilled in the art and will not be described in detail here.

Based on the same inventive concept, an embodiment of the present application further provides a storage medium, which stores computer instructions. When the computer instructions are executed on a computer, the computer executes the EGR control method discussed above.

In some possible embodiments, various aspects of the EGR control method provided by the present application can also be implemented in the form of a program product, which includes program code. When the program product is run on the device, the program code is used to enable the control device to execute the steps of the EGR control method according to various exemplary embodiments of the present application described above in this specification.

Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, devices, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

The present application is described with reference to the flowchart and/or block diagram of the method, device (system) and computer program product according to the embodiment of the present application. It should be understood that each process and/or box in the flowchart and/or block diagram, and the combination of the process and/or box in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for realizing the function specified in one process or multiple processes in the flowchart and/or one box or multiple boxes in the block diagram.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device that implements the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.

These computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.

Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims (4)

1. A method for EGR control, characterized in that the method comprises: The second-order differential equation of the EGR system is established, which is obtained by the following formula: in, is the second-order derivative of the valve plate rotation angle, /> J＝(J _g +n ² *J _m ), J _m is the moment of inertia of the DC motor rotor in the EGR system, u is the duty cycle of the EGR valve,/> is the first-order derivative of the valve disc rotation angle, θ is the valve disc rotation angle, n is the transmission gear ratio, R is the resistance, _kb is the coefficient of the relationship between current and electromagnetic torque, _T0 is the initial torque of the return spring in the static position, _Tf is the friction force, and _Tα is the airflow impact torque; According to the second-order differential equation, the expanded state equation of the EGR system is obtained: in, x ₁ =θ,/> x ₃ =f,/> According to the extended state equation, the extended state observer ESO is obtained: Among them, the estimated value of the state quantity x is The estimated value of output y is/> Observer gain matrix/> The ESO gain matrix L makes the characteristic root of the (A-LC) matrix in the left half of the complex plane; Obtaining a current EGR valve angle, a first-order derivative of the current EGR valve angle, and a disturbance through the ESO observation; Obtaining a first control amount according to an EGR valve angle reference value and the EGR current valve angle; According to the formula Calculate the second control amount, and, according to the formula/> Calculate the duty cycle of the EGR valve; wherein K _p (θ _setting - θ) + K _d (θ _setting - θ) is the first control variable, is the second control amount, θ _{is set} as the EGR valve angle reference value, _Kp is the first weight factor of (θ _setting - θ), _Kd is the second weight factor of (θ _setting - θ), f is the disturbance amount, k _s is the stiffness coefficient of the return spring, V _b is the battery voltage, _km is the coefficient of relationship between electromotive force and angular velocity, and k _b is the coefficient of relationship between current and electromagnetic torque; The current EGR valve angle is controlled according to the duty cycle. 2. An EGR control device, characterized in that the device comprises: The observation module establishes the second-order differential equation of the EGR system, which is obtained by the following formula: in, is the second-order derivative of the valve plate rotation angle, /> J＝(J _g +n ² *J _m ), J _m is the moment of inertia of the DC motor rotor in the EGR system, u is the duty cycle of the EGR valve,/> is the first-order derivative of the valve disc rotation angle, θ is the valve disc rotation angle, n is the transmission gear ratio, R is the resistance, _kb is the coefficient of the relationship between current and electromagnetic torque, _T0 is the initial torque of the return spring in the static position, _Tf is the friction force, and _Tα is the airflow impact torque; According to the second-order differential equation, the expanded state equation of the EGR system is obtained: in, x ₁ =θ,/> x ₃ =f,/> According to the extended state equation, the extended state observer ESO is obtained: Among them, the estimated value of the state quantity x is The estimated value of output y is/> Observer gain matrix/> The ESO gain matrix L makes the characteristic roots of the (A-LC) matrix in the left half of the complex plane; Obtaining a current EGR valve angle, a first-order derivative of the current EGR valve angle, and a disturbance through the ESO observation; A calculation module, which obtains a first control amount according to an EGR valve angle reference value and the EGR current valve angle; According to the formula Calculate the second control amount, and, according to the formula/> Calculate the duty cycle of the EGR valve; wherein K _p (θ _setting - θ) + K _d (θ _setting - θ) is the first control variable, is the second control amount, θ _{is set} as the EGR valve angle reference value, _Kp is the first weight factor of (θ _setting - θ), _Kd is the second weight factor of (θ _setting - θ), f is the disturbance amount, k _s is the stiffness coefficient of the return spring, V _b is the battery voltage, _km is the coefficient of relationship between electromotive force and angular velocity, and k _b is the coefficient of relationship between current and electromagnetic torque; The control module controls the current EGR valve angle according to the duty cycle. 3. An electronic device, comprising: Memory, used to store computer programs; A processor, configured to implement the method steps described in claim 1 when executing a computer program stored in the memory. 4. A computer-readable storage medium, characterized in that a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, the method steps described in claim 1 are implemented.