Engine control method and system based on throttle valve

Abstract

The present invention provides an engine control method and system based on a throttle valve, and relates to the technical field of engine control. The method comprises: combining the gas pressure upstream and downstream of the throttle valve, establishing an engine dynamics model with a throttle valve opening and an engine theoretical output power; linearizing the engine dynamics model under the engine idle condition, and outputting a linearized transfer function model of the engine; constructing an engine disturbance observer; calculating a power deviation value between the current engine output power and the target engine output power; based on the power deviation value, constructing an engine fractional-order PID controller in combination with the disturbance observation value of the disturbance observer as an active compensation item; obtaining a current disturbance estimation value of the engine by using the disturbance observer; inputting the current disturbance estimation value into the fractional-order PID controller, and outputting an actual throttle valve opening; and controlling the engine according to the actual throttle valve opening. The engine control accuracy is improved, and the overshoot phenomenon is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of engine control, and in particular to a throttle-valve-based engine control method and system. Background Art

[0002] In the engine, the throttle valve is located at the intake manifold, controlling the flow of air into the engine cylinder. It controls the engine's intake by adjusting the air flow, thereby affecting the engine's combustion and output power. The throttle valve works mainly by changing the valve opening, thereby affecting the air flow and ultimately adjusting the engine's operating state.

[0003] The throttle valve is an important component for controlling the engine's air intake. By adjusting its opening, it can directly affect the engine's power output, combustion efficiency and exhaust emissions. It can accurately adjust the air flow rate, thereby optimizing the engine's performance under different working conditions, improving fuel efficiency, reducing emissions, and enhancing the engine's response speed. In modern internal combustion engine equipment, this control method is an indispensable part of the engine management system.

[0004] Although there are many schemes for controlling engines based on throttle valves, the changes in airflow velocity caused by the gas pressure upstream and downstream of the throttle valve are not taken into account, resulting in inaccurate engine modeling and the inability to accurately control the engine operation through the throttle valve. In addition, in the actual control process after engine modeling, nonlinear control methods with high complexity and extremely sensitive to disturbances are often used directly for control, which is prone to overshoot and insufficient control stability, making it difficult to meet the high control accuracy requirements of engine scenarios. Summary of the invention

[0005] In order to solve the technical problems that the prior art does not take into account the changes in air flow velocity caused by the upstream and downstream gas pressures of the throttle valve, resulting in inaccurate engine modeling and the inability to accurately control the engine operation through the throttle valve, and in addition, in the actual control process after the engine modeling, a nonlinear control method with high complexity and extremely sensitive to disturbances is often directly used for control, which is prone to overshoot, insufficient control stability, and difficulty in meeting the high control accuracy requirements of the engine scene, the present invention provides an engine control method and system based on a throttle valve.

[0006] The technical solution provided by the embodiment of the present invention is as follows:

[0007] First aspect

[0008] An engine control method based on a throttle valve provided in an embodiment of the present invention includes:

[0009] S1: Combined with the gas pressure upstream and downstream of the throttle valve, an engine dynamics model with throttle valve opening and engine theoretical output power is established;

[0010] S2: Linearize the engine dynamics model under the engine idle condition and output the linearized transfer function model of the engine;

[0011] S3: Construct the engine disturbance observer in combination with the linearized transfer function model;

[0012] S4: Obtaining the target output power of the engine, and calculating the power deviation value between the current output power of the engine and the target output power of the engine;

[0013] S5: Based on the power deviation value, the disturbance observation value of the disturbance observer is combined as an active compensation term to construct a fractional-order PID controller for the engine;

[0014] S6: using a disturbance observer to obtain a current disturbance estimate of the engine;

[0015] S7: input the current disturbance estimation value into the fractional-order PID controller and output the actual throttle valve opening;

[0016] S8: Control the engine according to the actual throttle valve opening.

[0017] Second aspect

[0018] An engine control system based on a throttle valve provided by an embodiment of the present invention includes:

[0019] processor;

[0020] A memory having computer-readable instructions stored therein, wherein when the computer-readable instructions are executed by the processor, the throttle-valve-based engine control method as described in the first aspect is implemented.

[0021] The third aspect

[0022] An embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the engine control method based on a throttle valve as described in the first aspect is implemented.

[0023] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0024] In the present invention, the gas pressure upstream and downstream of the throttle valve is combined to accurately divide the engine pressure state under different gas pressures, establish an engine dynamics model with throttle valve opening and engine theoretical output power, and provide a data basis for accurate control of the engine. Afterwards, the engine dynamics model is linearized under the engine idle condition, and the linearized transfer function model of the engine is output to reduce the disturbance sensitivity and overshoot phenomenon, which can accurately describe the key dynamic behavior of the system and avoid the complexity of direct nonlinear control. Based on this, a disturbance observer is established to monitor and compensate for external disturbances in real time, and then the disturbance term is added to the power deviation value to use the fractional-order PID controller to regulate the actual throttle valve opening to approach the target output power of the engine. By introducing fractional-order integral and differential terms, the frequency response and time response of the system can be adjusted more flexibly, providing more delicate error accumulation and rate of change control, while maintaining system stability. Reduce oscillation and overshoot, especially when dealing with complex systems or with external disturbances, the fractional-order controller has a smoother error response to different frequencies, thereby significantly improving the dynamic performance and steady-state accuracy of the system and achieving more accurate control. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 A schematic flow chart of a throttle valve-based engine control method provided in an embodiment of the present invention;

[0027] Figure 2 A schematic structural diagram of a throttle valve-based engine control system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0029] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0030] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0031] Reference Manual Attached Figure 1 , showing a flow chart of a throttle valve-based engine control method provided in an embodiment of the present invention.

[0032] An embodiment of the present invention provides a throttle-based engine control method, which can be implemented by a throttle-based engine control device, which can be a terminal or a server. The processing flow of the throttle-based engine control method may include the following steps:

[0033] S1: Combined with the gas pressure upstream and downstream of the throttle valve, an engine dynamics model with throttle valve opening and engine theoretical output power is established.

[0034] Among them, the gas pressure upstream of the throttle valve refers to the gas pressure before the throttle valve, usually the pressure of the air entering the throttle valve. The gas pressure downstream of the throttle valve refers to the gas pressure after passing through the throttle valve, that is, the air pressure before entering the engine cylinder. These two pressures affect the gas flow rate and flow through the throttle valve, and then affect the engine's intake volume and combustion process. The throttle valve opening refers to the opening and closing angle of the throttle valve plate. The larger the opening, the more air enters the engine. The smaller the opening, the less air flow. The opening directly affects the air supply to the engine. The theoretical output power of the engine refers to the ideal power output that the engine can produce under given conditions (such as intake volume, fuel volume, etc.). The engine dynamics model is a mathematical model that describes the dynamic changes of engine intake, combustion, output power, etc. This model reflects how throttle valve adjustment affects the overall behavior of the engine.

[0035] By combining the gas pressure upstream and downstream of the throttle valve, the throttle valve opening and the theoretical output power of the engine to establish a dynamic model, the nonlinear relationship between air flow and engine output power can be accurately captured, providing an accurate description of the engine operating state, and providing a reliable data basis for subsequent control, making engine control more precise, stable and efficient.

[0036] In a possible implementation manner, the engine dynamics model is specifically:

[0037] in, represents the gas mass flow rate through the throttle valve, Indicates the throttle valve opening The effective geometric opening of represents the throttle valve flow coefficient, Indicates the pressure upstream of the throttle valve, Table throttle valve upstream temperature,R is the gas constant, Indicates the pressure downstream of the throttle valve, Indicates about and The pressure ratio function, It represents the theoretical output power of the engine, AFR represents the air-fuel ratio of the engine, Indicates engine combustion efficiency, LHV indicates lower heating value of engine fuel, is the specific heat capacity of air, π represents pi, r Indicates the radius of the pipe where the throttle valve is located. Indicates the maximum radius of the throttle valve, and cos represents the cosine function. Among them, the gas mass flow rate refers to the mass of the gas flowing per unit time, and the throttle valve flow coefficient measures the efficiency of the air flow through the throttle valve. The specific value of the air specific heat capacity is 1.4. The lower calorific value of the engine fuel is the heat released when each kilogram of fuel is completely burned.

[0038] It should be noted that the established engine dynamics model distinguishes the engine pressure state under different pressure states through judgment conditions, and then divides it into critical flow state and non-critical flow state, completes the accurate modeling of the engine, and provides a theoretical basis for high-precision control of the engine. The established engine dynamics model considers the relationship between multiple physical quantities such as throttle opening, gas mass flow rate, pressure ratio, etc. in detail. Through accurate geometric opening and flow characteristic functions, it can accurately describe the working state and power output of the engine, making the control strategy more robust and efficient, especially providing more accurate power prediction and regulation under complex working conditions.

[0039] S2: Linearize the engine dynamics model under the engine idle condition and output the linearized transfer function model of the engine.

[0040] Among them, the engine idle condition is the no-load running state of the engine. Linearization is the process of describing a nonlinear system near a specific operating point with a linear approximate model. Through linearization, complex nonlinear equations can be simplified into linear equations at local operating points (such as idle conditions), which is convenient for processing using traditional control methods. The linearized transfer function model represents the relationship between the throttle opening (input) and the engine output power (output) in a linearized manner, ignoring nonlinear factors, thereby simplifying the description of the system's dynamic characteristics, and is suitable for system analysis at idle or within a specific small range.

[0041] By converting the nonlinear dynamic model into a linearized transfer function model, the complex system can use standard linear control technology, which simplifies the control design and implementation, improves the control efficiency and accuracy, and effectively reduces the overshoot phenomenon caused by excessive sensitivity to external disturbances in the nonlinear control process.

[0042] In a possible implementation, S2 specifically includes:

[0043] S201: collecting engine balance parameters under the engine idle condition, wherein the engine balance parameters include throttle valve balance opening, throttle valve upstream balance pressure, throttle valve downstream balance pressure, throttle valve balance gas mass flow rate and engine balance output power.

[0044] S202: Obtaining theoretical parameters of the engine under balanced output power of the engine based on the engine dynamics model, and determining disturbance variables under the engine idle condition:

[0045] in, , , , , and They represent the throttle valve balance opening, the throttle valve upstream balance pressure, the throttle valve downstream balance pressure, the throttle valve upstream balance temperature, the throttle valve balance gas mass flow rate and the engine balance output power respectively. , , , and They respectively represent the throttle valve opening disturbance variable under engine idle conditions, the throttle valve upstream pressure disturbance variable, the throttle valve downstream pressure disturbance variable, the throttle valve upstream temperature disturbance variable, the throttle valve gas mass flow disturbance variable and the engine output power disturbance variable.

[0046] S203: Perform Taylor expansion on the engine balance parameter at the engine balance parameter to obtain a linear approximate equation for the gas mass flow rate and a linear approximate equation for the engine output power:

[0047] in, represents partial derivatives, , and Both represent intermediate variables.

[0048] S204: A time constant is introduced to describe the response speed of the engine to the throttle valve opening, and a system response equation is established with the throttle valve opening change as input data and the engine output power change as output data: in, represents the time constant, and Respectively t The change in engine output power and throttle valve opening at each moment.

[0049] S205: Perform Laplace transform on the system response equation to obtain the frequency domain system response equation: in, s represents the Laplace transform variable, and Respectively expressed in s The frequency domain engine output power change and throttle valve opening change under.

[0050] S206: Perform algebraic transformation on the frequency domain system response equation to obtain a linearized transfer function model: in, Represents the transfer function of the linearized transfer function model.

[0051] Specifically, by collecting the balance parameters under the engine idle condition, the process of linearizing the complex nonlinear system first approximates the throttle valve opening, gas mass flow rate and engine output power through Taylor expansion to ensure that the model is simplified under small disturbances near the equilibrium point and improve the calculation efficiency. The time constant is introduced to reflect the dynamic characteristics of the system, capture the delay characteristics of the throttle valve response, and use Laplace transform to convert the differential equation into a frequency domain algebraic equation to facilitate analysis and design of the controller. The linearized transfer function model obtained in this way not only simplifies the complex nonlinear relationship and facilitates analysis, but also responds to disturbances quickly, improving the accuracy of control and the stability of the system. Through frequency domain analysis, a more accurate control strategy is designed to reduce overshoot and system instability.

[0052] S3: Construct the engine disturbance observer in combination with the linearized transfer function model.

[0053] Among them, the disturbance observer is used to estimate the unknown disturbance or interference in the system. It measures the input and output of the system and combines the known system model (linearized transfer function model) to infer the external disturbance or uncertainty factors to the system. The role of the disturbance observer is to estimate and compensate for these disturbances in real time, thereby ensuring the control accuracy and stability of the system. In engine control, disturbances may come from factors such as gas pressure changes, load fluctuations, or changes in the external environment. Through the disturbance observer, the system can infer the disturbance value without directly measuring the disturbance and make corresponding control adjustments.

[0054] By combining the linearized transfer function model to build a disturbance observer, it is possible to monitor and compensate for external disturbances in real time, enhance the system's anti-disturbance capability, improve control accuracy, and reduce the impact of external environmental changes on engine performance, ensuring system stability and response speed.

[0055] In a possible implementation, the disturbance observer is specifically: in, express t Estimate the disturbance value at each moment, express t The actual engine output power at the moment, express t Throttle valve opening at any time, Represents the linearized transfer function model The inverse of.

[0056] It should be noted that the established disturbance observer provides feedback on the difference between the actual output power and the theoretical model, and uses the inverse of the transfer function model to estimate the disturbance value in real time. It can dynamically capture the unknown disturbances in the system, allowing the system to compensate for external interference during operation, thereby improving the robustness, stability and accuracy of the system and effectively reducing the impact of disturbances on control performance.

[0057] S4: Obtain the target output power of the engine, and calculate the power deviation value between the current output power of the engine and the target output power of the engine.

[0058] Among them, the target output power is the output value that the system hopes to achieve. It is the ideal power output that the engine should achieve under specific working conditions. The current output power is the power output value generated by the engine in real time during actual operation. The rate deviation value is the difference between the target output power and the current output power. It is used to measure the error of the system. By calculating the deviation between the target output power and the current output power, a key error signal is provided to drive the controller for real-time adjustment to ensure that the actual power output of the engine gradually approaches the target value, thereby improving the control accuracy and responsiveness of the system and ensuring stable and efficient operation of the engine.

[0059] In a possible implementation manner, the power deviation value is specifically: in, express t The power deviation value at the moment, and They represent the target engine output power and the current engine output power respectively.

[0060] By comparing the target power with the current output power, the power deviation is obtained. This method can detect the system performance deviation in real time, help dynamically adjust the throttle valve opening, ensure that the engine output power is always close to the target power, and improve the control accuracy and system responsiveness.

[0061] S5: Based on the power deviation value, the disturbance observation value of the disturbance observer is combined as an active compensation term to construct a fractional-order PID controller for the engine.

[0062] Among them, the active compensation term is the external disturbance value estimated by the disturbance observer. It reflects the impact of external disturbances (such as gas pressure changes, load fluctuations, etc.) on the engine output power. By adding the disturbance observation value as an active compensation term to the controller, the external disturbance can be compensated in real time during the adjustment process to reduce its impact on the engine performance. The fractional-order PID controller is an extension of the traditional PID controller. It introduces fractional-order integral and differential terms, which enhances the controller's response to different frequency components.

[0063] By combining the power deviation value with the disturbance observation value, a fractional-order PID controller is constructed. By introducing fractional-order integral and differential terms, the frequency response and time response of the system can be adjusted more flexibly, providing more delicate error accumulation and rate of change control, while maintaining system stability while reducing oscillation and overshoot. Especially when dealing with complex systems or when there are external disturbances, the fractional-order controller has a smoother error response to different frequencies, thereby significantly improving the dynamic performance and steady-state accuracy of the system, achieving more precise control, and being able to accurately adjust the system dynamics while compensating for external disturbances, providing a more flexible error correction mechanism, effectively improving control accuracy, anti-disturbance capability and system stability, and ensuring that the engine output power accurately approaches the target value.

[0064] In a possible implementation, the fractional-order PID controller is specifically: in, Indicates the power deviation correction value, Indicates consideration of active compensation items of t The throttle valve opening at time t, where the active compensation term is obtained by the disturbance observer t Time perturbation observation , , , Represent the proportional gain, integral gain and differential gain respectively, Indicates the order of integration The fractional integral term of , Represents the differential order The fractional differential term of .

[0065] It should be noted that the fractional-order PID controller established in this way can adjust the throttle valve opening more accurately by combining the compensation functions of proportional, integral, differential terms and disturbance observer. The introduction of fractional-order integral and differential terms increases the flexibility of the controller, enabling it to achieve precise dynamic control under a wider range of working conditions, improve the flexibility and robustness of the system response, effectively reduce overshoot and oscillation, and improve the overall control performance.

[0066] In a possible implementation manner, after S5, the method further includes:

[0067] S5A: With the goal of minimizing the steady-state error, the active compensation term is set to zero under idle conditions, and the parameters of the fractional-order PID controller are optimized by a particle swarm optimization algorithm with a linearly decreasing inertia weight. The fractional-order PID controller parameters include proportional gain, integral gain, differential gain, integral order, and differential order.

[0068] Among them, the inertia weight controls the speed of particle movement. The linear decreasing inertia weight means that the inertia weight gradually decreases from a larger initial value. The purpose of this approach is to maintain a larger search range in the early stage of the algorithm in order to explore more possible solutions, and to reduce the weight in the later stage to concentrate on searching for local optimal solutions and improve convergence accuracy. Particle swarm optimization algorithm is an optimization algorithm based on swarm intelligence. It simulates the foraging behavior of bird flocks, allowing multiple particles to move in the solution space. Each particle updates its position based on its own experience and the best experience in the group, thereby gradually finding the optimal solution to the problem.

[0069] By using the particle swarm optimization algorithm, combined with the linear decreasing inertia weight, the parameters of the fractional-order PID controller can be effectively searched and optimized, so that the controller can maintain stable and efficient performance under different working conditions. This can automatically adjust the control parameters, reduce human intervention, significantly improve the accuracy and response speed of the controller, and reduce the steady-state error, thereby improving the overall control effect of the system.

[0070] In a possible implementation, S5A specifically includes:

[0071] S5A1: Determine the objective function for optimizing the parameters of the fractional-order PID controller: in, J Represents the objective function.

[0072] S5A2: Initialize the fractional-order PID controller parameters as particles and determine the position and velocity of each particle, where the particle position is a parameter vector based on the fractional-order PID controller parameters: in, Indicates iThe particle position of each particle, Indicates i Particles in t = 0 particle speed, Respectively represent i Particle The velocity of the particle at the initial time.

[0073] S5A3: Determine the particle position update rule and particle velocity update rule: Particle position update rule:

[0074] Particle velocity update rule: in, and Respectively t The particle position at time t +1 moment particle position, and Respectively t The particle speed at time t +1 moment particle speed, Indicates the inertia of controlling particle movement t The inertia weight decreases linearly at all times, and Both represent a learning factor of 2, and Respectively represent the first random number and the second random number in the range of 0 to 1, Represents particles i The best location in history, represents the global best position, that is, the best historical position found by all particles, and denote the maximum inertia weight and the minimum inertia weight respectively, represents the particle's first i The probability density of particles, log represents the logarithmic function, N represents the total number of particles, express t The entropy value of the particle group at the moment is the entropy value of all particles at t The entropy value at the moment, Indicates that it is used for normalization t Particle swarm entropy value at time The ideal maximum entropy value.

[0075] Among them, the maximum inertia weight and the minimum inertia weight can be set according to actual needs. The value range of the maximum inertia weight is 0.8 to 1.2, and can be specifically set to 0.9. The value range of the minimum inertia weight is 0.2 to 0.4, and can be specifically set to 0.4.

[0076] By introducing the particle swarm entropy value into the linearly decreasing inertia weight, the search strategy can be dynamically adjusted according to the distribution of the particle swarm. When the entropy value is large, it means that the particle distribution is more dispersed, and the inertia weight should be kept large to promote global search. When the entropy value is small, it means that the particles are gradually concentrated, and the inertia weight is reduced to improve the local search accuracy. This dynamic adjustment can better balance global exploration and local development, enhance the optimization effect, and improve the convergence speed and accuracy.

[0077] It should be noted that by combining the inertia weight with the entropy value, the algorithm can dynamically adjust the search strategy. In the early stage, the larger inertia weight prompts the particle swarm to conduct a global search to avoid falling into the local optimum. As the entropy value decreases, the inertia weight gradually decreases, prompting the particle swarm to conduct a more accurate local search when approaching the optimal solution, thereby improving the convergence speed and accuracy. This dynamic adjustment mechanism ensures a good balance between the global exploration ability and the local convergence ability of the optimization process.

[0078] S5A4: Update the particles according to the particle position update rule and the particle velocity update rule, and calculate the objective function value after the particle update.

[0079] S5A5: Determine whether the difference between the objective function value after the particle is updated and the objective function value before the particle is updated is less than the preset difference. If so, output the updated global optimal position as the target particle position and enter step S5A7; otherwise, enter step S5A6.

[0080] It should be noted that those skilled in the art can set the size of the preset difference according to actual needs, and the present invention is not limited thereto.

[0081] S5A6: Determine whether the current number of iterations is less than the preset number of iterations. If so, add 1 to the current number of iterations and return to step S5A4. Otherwise, output the global optimal position within the preset number of iterations as the target particle position.

[0082] It should be noted that those skilled in the art can set the preset number of iterations according to actual needs, and the present invention does not limit this.

[0083] S5A7: Output the target particle position and obtain the optimized PID controller parameters.

[0084] It should be noted that the particle swarm optimization algorithm balances the ability of global search and local search through linearly decreasing inertia weight, so that particles can explore a larger solution space in the early stage, avoid falling into the local optimum, and gradually converge in the later stage to improve the accuracy of the solution. At the same time, the particle swarm entropy value is introduced, combined with the learning factor and random number, and the particle speed and position update are dynamically adjusted, making the parameter optimization process more stable and efficient. By iteratively calculating the objective function, the parameters of the fractional-order PID controller can be automatically optimized, the response speed, accuracy and robustness of the control system can be improved, and it is suitable for adaptive control under complex working conditions.

[0085] S6: Using the disturbance observer to obtain the current disturbance estimate of the engine.

[0086] S7: Input the current disturbance estimation value into the fractional-order PID controller and output the actual throttle valve opening.

[0087] Among them, the actual throttle valve opening is the angle at which the throttle valve should be opened, calculated by the fractional-order PID controller based on the input power deviation value and the disturbance estimation value. This opening determines the air flow entering the engine, which in turn affects the combustion efficiency and engine output power. The actual throttle valve opening is a key variable for controlling the dynamic response and output power of the engine. By inputting the disturbance estimation value into the fractional-order PID controller, the actual throttle valve opening is calculated, so that the intake volume is dynamically adjusted according to the real-time working conditions, ensuring that the engine output power accurately responds to the target power change, improving the control accuracy and real-time performance of the system, and maintaining the efficient and stable operation of the engine.

[0088] S8: Control the engine according to the actual throttle valve opening.

[0089] In the actual application process, a dynamic model is established by combining the gas pressure upstream and downstream of the throttle valve, and it is linearized under idle conditions to generate a linearized transfer function model. Based on this model, a disturbance observer is constructed to obtain the deviation value between the target and the actual power, which is input into the fractional-order PID controller together with the disturbance estimation value. The controller calculates and outputs the actual throttle valve opening according to these inputs, and finally controls the output power of the engine by adjusting the throttle valve opening to make it approach the target value. This method simplifies complex systems through dynamic modeling and linearization, and introduces a disturbance observer for real-time disturbance compensation. Combined with the flexible adjustment of the fractional-order PID controller, the system's anti-disturbance ability, control accuracy and dynamic response speed are improved, ensuring the stability and efficiency of the engine under complex conditions.

[0090] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0091] In the present invention, the gas pressure upstream and downstream of the throttle valve is combined to accurately divide the engine pressure state under different gas pressures, establish an engine dynamics model with throttle valve opening and engine theoretical output power, and provide a data basis for accurate control of the engine. Afterwards, the engine dynamics model is linearized under the engine idle condition, and the linearized transfer function model of the engine is output to reduce the disturbance sensitivity and overshoot phenomenon, which can accurately describe the key dynamic behavior of the system and avoid the complexity of direct nonlinear control. Based on this, a disturbance observer is established to monitor and compensate for external disturbances in real time, and then the disturbance term is added to the power deviation value to use the fractional-order PID controller to regulate the actual throttle valve opening to approach the target output power of the engine. By introducing fractional-order integral and differential terms, the frequency response and time response of the system can be adjusted more flexibly, providing more delicate error accumulation and rate of change control, while maintaining system stability. Reduce oscillation and overshoot, especially when dealing with complex systems or with external disturbances, the fractional-order controller has a smoother error response to different frequencies, thereby significantly improving the dynamic performance and steady-state accuracy of the system and achieving more accurate control.

[0092] Reference Manual Attached Figure 2 , showing a structural schematic diagram of a throttle valve-based engine control system provided by the present invention.

[0093] The present invention further provides a throttle-based engine control system 20, which is applied to the above-mentioned throttle-based engine control method, comprising:

[0094] Processor 201.

[0095] The memory 202 stores computer-readable instructions. When the computer-readable instructions are executed by the processor 201 , the throttle-based engine control method of the method embodiment is implemented.

[0096] The throttle-based engine control system 20 provided in the present invention can execute the above-mentioned throttle-based engine control method and achieve the same or similar technical effects. To avoid repetition, the present invention will not go into details.

[0097] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0098] In the present invention, the gas pressure upstream and downstream of the throttle valve is combined to accurately divide the engine pressure state under different gas pressures, establish an engine dynamics model with throttle valve opening and engine theoretical output power, and provide a data basis for accurate control of the engine. Afterwards, the engine dynamics model is linearized under the engine idle condition, and the linearized transfer function model of the engine is output to reduce the disturbance sensitivity and overshoot phenomenon, which can accurately describe the key dynamic behavior of the system and avoid the complexity of direct nonlinear control. Based on this, a disturbance observer is established to monitor and compensate for external disturbances in real time, and then the disturbance term is added to the power deviation value to use the fractional-order PID controller to regulate the actual throttle valve opening to approach the target output power of the engine. By introducing fractional-order integral and differential terms, the frequency response and time response of the system can be adjusted more flexibly, providing more delicate error accumulation and rate of change control, while maintaining system stability. Reduce oscillation and overshoot, especially when dealing with complex systems or with external disturbances, the fractional-order controller has a smoother error response to different frequencies, thereby significantly improving the dynamic performance and steady-state accuracy of the system and achieving more accurate control.

[0099] It should be understood that the processor in the embodiment of the present invention may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0100] It should also be understood that the memory in the embodiments of the present invention may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of random access memory (RAM) are available, such as static RAM (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0101] The above embodiments can be implemented in whole or in part by software, hardware (such as circuits), firmware or any other combination. When implemented by software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that contains one or more available media sets. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a tape), an optical medium (for example, a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state hard disk.

[0102] It should be understood that the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship, but it may also indicate an "and / or" relationship. Please refer to the context for specific understanding.

[0103] In the present invention, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0104] It should be understood that in various embodiments of the present invention, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0105] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0106] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described equipment, devices and units can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0107] In the several embodiments provided by the present invention, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0108] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0109] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0110] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program codes.

[0111] An embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the throttle-valve-based engine control method described in the method embodiment is implemented.

[0112] A computer-readable storage medium provided by the present invention can implement the steps and effects of the throttle-based engine control method of the above method embodiment. To avoid repetition, the present invention will not go into details.

[0113] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0114] In the present invention, the gas pressure upstream and downstream of the throttle valve is combined to accurately divide the engine pressure state under different gas pressures, establish an engine dynamics model with throttle valve opening and engine theoretical output power, and provide a data basis for accurate control of the engine. Afterwards, the engine dynamics model is linearized under the engine idle condition, and the linearized transfer function model of the engine is output to reduce the disturbance sensitivity and overshoot phenomenon, which can accurately describe the key dynamic behavior of the system and avoid the complexity of direct nonlinear control. Based on this, a disturbance observer is established to monitor and compensate for external disturbances in real time, and then the disturbance term is added to the power deviation value to use the fractional-order PID controller to regulate the actual throttle valve opening to approach the target output power of the engine. By introducing fractional-order integral and differential terms, the frequency response and time response of the system can be adjusted more flexibly, providing more delicate error accumulation and rate of change control, while maintaining system stability. Reduce oscillation and overshoot, especially when dealing with complex systems or with external disturbances, the fractional-order controller has a smoother error response to different frequencies, thereby significantly improving the dynamic performance and steady-state accuracy of the system and achieving more accurate control.

[0115] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

[0116] There are a few points to note:

[0117] (1) The drawings of the embodiments of the present invention only involve structures related to the embodiments of the present invention. Other structures may refer to conventional designs.

[0118] (2) For the sake of clarity, in the drawings used to describe the embodiments of the present invention, the thickness of layers or regions is exaggerated or reduced, that is, these drawings are not drawn according to the actual scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element or there may be intermediate elements.

[0119] (3) In the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0120] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A throttle-based engine control method, characterized in that: include: S1: Combined with the gas pressure upstream and downstream of the throttle valve, an engine dynamics model with throttle valve opening and engine theoretical output power is established; S2: linearizing the engine dynamics model under the engine idle condition, and outputting a linearized transfer function model of the engine; S3: constructing a disturbance observer of the engine in combination with the linearized transfer function model; S4: Obtaining the target output power of the engine, and calculating the power deviation value between the current output power of the engine and the target output power of the engine; S5: constructing a fractional-order PID controller of the engine based on the power deviation value and the disturbance observation value of the disturbance observer as an active compensation term; S6: using the disturbance observer to obtain a current disturbance estimation value of the engine; S7: inputting the current disturbance estimation value into the fractional-order PID controller, and outputting the actual throttle valve opening; S8: Controlling the engine according to the actual throttle valve opening.

2. The throttle-based engine control method according to claim 1, characterized in that: The engine dynamics model is specifically: in, represents the gas mass flow rate through the throttle valve, Indicates the throttle valve opening The effective geometric opening of represents the throttle valve flow coefficient, Indicates the pressure upstream of the throttle valve, represents the temperature upstream of the throttle valve, R is the gas constant, Indicates the pressure downstream of the throttle valve, Indicates about and Pressure ratio function, represents the theoretical output power of the engine, AFR represents the air-fuel ratio of the engine, Indicates engine combustion efficiency, LHV indicates lower heating value of engine fuel is the specific heat capacity of air, π represents pi, r Indicates the radius of the pipe where the throttle valve is located. represents the maximum radius of the throttle valve, and cos represents the cosine function.

3. The throttle-based engine control method according to claim 2, characterized in that: The S2 specifically includes: S201: collecting engine balance parameters under the engine idle condition, wherein the engine balance parameters include throttle valve balance opening, throttle valve upstream balance pressure, throttle valve downstream balance pressure, throttle valve balance gas mass flow rate and engine balance output power; S202: Acquire theoretical parameters of the engine at the balanced output power of the engine based on the engine dynamics model, and determine disturbance variables at the engine idle condition: in, They represent the throttle valve balance opening, the throttle valve upstream balance pressure, the throttle valve downstream balance pressure, the throttle valve upstream balance temperature, the throttle valve balance gas mass flow rate and the engine balance output power respectively. They represent the throttle valve opening disturbance variable, the throttle valve upstream pressure disturbance variable, the throttle valve downstream pressure disturbance variable, the throttle valve upstream temperature disturbance variable, the throttle valve gas mass flow disturbance variable and the engine output power disturbance variable under the engine idle condition respectively; S203: Performing Taylor expansion on the engine balance parameter at the engine balance parameter to obtain a gas mass flow linear approximation equation and an engine output power linear approximation equation: in, represents partial derivatives, All represent intermediate variables; S204: Introducing a time constant to describe the response speed of the engine to the throttle valve opening, establishing a system response equation with the throttle valve opening change as input data and the engine output power change as output data: in, represents the time constant, and Respectively t The change in engine output power and throttle valve opening at each moment; S205: Perform Laplace transform on the system response equation to obtain the frequency domain system response equation: in, s represents the Laplace transform variable, and Respectively expressed in s The frequency domain engine output power variation and throttle valve opening variation under ; S206: Performing an algebraic transformation on the frequency domain system response equation to obtain the linearized transfer function model: in, Represents the transfer function of the linearized transfer function model.

4. The throttle-based engine control method according to claim 1, characterized in that: The disturbance observer is specifically: in, express t Estimate the disturbance value at each moment, express t The actual engine output power at the moment, express t Throttle valve opening at any time, Represents the linearized transfer function model The inverse of.

5. The throttle-based engine control method according to claim 1, characterized in that: The power deviation value is specifically: in, express t The power deviation value at the moment, and They represent the target engine output power and the current engine output power respectively.

6. The throttle-based engine control method according to claim 5, characterized in that: The fractional-order PID controller is specifically: in, Indicates the power deviation correction value, Indicates consideration of active compensation items of t The throttle valve opening at time t, where the active compensation term is obtained by the disturbance observer t Time perturbation observation , , , Represent the proportional gain, integral gain and differential gain respectively, Indicates the order of integration The fractional integral term of Represents the differential order The fractional differential term of 7. The throttle-based engine control method according to claim 1, characterized in that: After S5, the following steps are also included: S5A: With the goal of minimizing the steady-state error, that is, setting the active compensation term to zero under idle conditions, the fractional-order PID controller parameters are optimized by a particle swarm optimization algorithm with a linearly decreasing inertia weight, wherein the fractional-order PID controller parameters include proportional gain, integral gain, differential gain, integral order and differential order.

8. The throttle-based engine control method according to claim 7, characterized in that: The S5A specifically includes: S5A1: Determine the objective function for optimizing the parameters of the fractional-order PID controller: in, J represents the objective function; S5A2: Initialize the fractional-order PID controller parameters as particles, and determine the position and velocity of each particle, wherein the particle position is a parameter vector based on the fractional-order PID controller parameters: in, Indicates i The particle position of each particle, Indicates i Particles in t = 0 particle speed, Respectively represent i Particle The particle velocity at the initial moment; S5A3: Determine the particle position update rule and particle velocity update rule: Particle position update rule: Particle velocity update rule: in, and Respectively t The particle position at time t +1 moment particle position, and Respectively t The particle speed at time t +1 moment particle speed, Indicates the inertia of controlling particle movement t The inertia weight decreases linearly at all times, and Both represent a learning factor of 2, and represent the first random number and the second random number in the range of 0 to 1 respectively, Represents particles i The best location in history, represents the global best position, that is, the best historical position found by all particles, and denote the maximum inertia weight and the minimum inertia weight respectively, represents the particle's first i The probability density of particles, log represents the logarithmic function, N represents the total number of particles, express t The entropy value of the particle group at the moment is the entropy value of all particles at t The entropy value at the moment, Indicates that it is used for normalization t Particle swarm entropy value at time The ideal maximum entropy value of S5A4: updating the particle according to the particle position update rule and the particle velocity update rule, and calculating the objective function value after the particle is updated; S5A5: Determine whether the difference between the objective function value after the particle is updated and the objective function value before the particle is updated is less than a preset difference. If so, output the updated global optimal position as the target particle position and proceed to step S5A7. Otherwise, proceed to step S5A6. S5A6: Determine whether the current iteration number is less than the preset iteration number. If so, add 1 to the current iteration number and return to step S5A4. Otherwise, output the global best position within the preset iteration number as the target particle position. S5A7: Output the target particle position and obtain the optimized PID controller parameters.

9. An engine control system based on a throttle valve, characterized in that: include: A processor; a memory having computer-readable instructions stored thereon, wherein when the computer-readable instructions are executed by the processor, the throttle-valve-based engine control method according to any one of claims 1 to 8 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the throttle valve-based engine control method according to any one of claims 1 to 8 is implemented.

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