Torque control method, device and equipment of natural gas engine and medium

Abstract

The invention provides a torque control method, device and equipment for a natural gas engine and a medium, and the method comprises the steps that a target control mode currently required by the natural gas engine is determined, and target parameters corresponding to the target control mode are obtained; inputting the target parameter into a preset throttle opening formula to obtain a target throttle opening; controlling the torque of the natural gas engine according to the target throttle opening; wherein the throttle opening formula is obtained by combining a throttle equation for throttle control and a speed density normal equation. According to the method, the throttle equation used for throttle valve control and the speed density normal equation are combined by utilizing the characteristics of the natural gas engine to obtain the throttle valve opening degree formula, and for different target control modes, the throttle valve opening degree formula adopts different target parameters to calculate the throttle valve opening degree; the torque corresponding to the opening degree of the throttle valve can adapt to the target control mode, and therefore the controllability of the natural gas engine is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engine control, in particular to a torque control method and device of a natural gas engine, an electronic device and a storage medium. BACKGROUND

[0002] Natural gas is a clean energy, and its main component is methane. The main product after combustion is carbon dioxide and water. Therefore, natural gas vehicles have obvious advantages in exhaust emission. Compared with vehicles using gasoline or diesel, the particulate matter emission of natural gas vehicles is almost zero, and the emission of carbon monoxide and other substances is also significantly reduced. The intake path of the natural gas engine is: air filter→supercharger→intercooler→throttle valve→intake manifold→cylinder. The output torque of the engine is realized by controlling the intake amount through the throttle valve, and the torque control of the engine is realized by controlling the supercharging pressure before the throttle valve through the supercharger.

[0003] There are two existing torque control schemes for natural gas engines: 1. According to the required torque of the engine, the required throttle opening is obtained by table lookup, and then the required supercharger supercharging pressure is obtained by table lookup according to the throttle opening. In this scheme, the corresponding relationship between the throttle valve and the supercharger is fixed, which is too rigid and cannot adjust the corresponding relationship between the throttle valve and the supercharger at will according to the performance requirements. 2. According to the required torque of the engine, the required intake amount is obtained by table lookup, and then the required throttle opening is obtained according to the throttle formula based on the required intake amount; at the same time, the required supercharging pressure is obtained by table lookup according to the required torque. In this scheme, the control process of the throttle valve and the supercharger is too rigid. Only the flow rate before and after the throttle valve can be controlled through the throttle valve, but the pressure ratio before and after the throttle valve cannot be controlled.

[0004] Based on the above two schemes, the pressure ratio before and after the throttle valve or the pressure after the throttle valve cannot be quickly controlled, resulting in poor controllability of the torque or speed of the natural gas engine, which cannot meet the user's requirements. SUMMARY

[0005] The purpose of the present application is to provide a torque control method, device, electronic device and storage medium of a natural gas engine to improve the controllability of the natural gas engine.

[0006] In a first aspect, an embodiment of the present application provides a torque control method of a natural gas engine, comprising: determining a target control mode required by a current natural gas engine; obtaining a target parameter corresponding to the target control mode; inputting the target parameter into a preset throttle opening formula to obtain a target throttle opening; controlling the torque of the natural gas engine according to the target throttle opening; The throttle opening degree formula is obtained by combining a throttle control equation with a velocity-density method equation.

[0007] In a possible implementation, the throttle opening degree formula is obtained by combining a throttle control equation with a velocity-density method equation, and includes: S1, the throttle control equation is as follows: ; Wherein, TPS is the throttle opening degree; k 0 is a correction coefficient based on air temperature, map Pth is the pressure after the throttle, ptp Pth is the pressure before the throttle, f ( map / ptp ) is a correction coefficient based on the ratio of the pressure before and after the throttle, q m1 Qth is the air flow through the throttle; S2, the velocity-density method equation for throttle control is as follows: ; Wherein, q m2 Q is the air flow into the engine cylinder, b is the EGR partial pressure and the fuel gas partial pressure, and a is the pressure flow conversion coefficient; S3, according to the characteristics of the natural gas engine, the air flow through the throttle q m1 is equivalent to the air flow into the engine cylinder q m2 The throttle control equation is combined with the velocity-density method equation to obtain the following throttle opening degree formula: .

[0008] In a possible implementation, the target control mode is a torque control mode, and the target parameters corresponding to the torque control mode include: an actual pressure before the throttle ptp and a set pressure after the throttle map_set .

[0009] In a possible implementation, the target control mode is a speed control mode, and the target parameters corresponding to the speed control mode include: a set pressure before the throttle ptp_set and a set pressure after the throttle map_set .

[0010] In a possible implementation, the method further includes: If the absolute value of the difference between the actual value and the preset value of the manifold pressure is not greater than the first limit value, no adjustment is needed. If the absolute value of the difference between the actual value and the preset value of the manifold pressure is not greater than the first limit value, no adjustment is needed. If the absolute value of the difference between the actual value and the preset value of the manifold pressure is greater than the first limit value, a or b in the throttle opening degree formula is adjusted according to the throttle pressure ratio before and after the throttle, until the absolute value of the difference between the actual value and the preset value of the manifold pressure is not greater than the first limit value.

[0011] In a possible implementation, the adjusting a or b in the throttle opening degree formula according to the throttle pressure ratio before and after the throttle includes: If the throttle pressure ratio before and after the throttle is greater than a second limit value, a is decreased by a first preset step size; If the throttle pressure ratio before and after the throttle is not greater than the second limit value, b is increased by a second preset step size.

[0012] In a second aspect, an embodiment of the present application provides a torque control device of a natural gas engine, including: A determination module configured to determine a target control mode required by a current natural gas engine; An acquisition module configured to acquire a target parameter corresponding to the target control mode; A calculation module configured to input the target parameter into a preset throttle opening degree formula to obtain a target throttle opening degree; A control module configured to control torque of the natural gas engine according to the target throttle opening degree. The throttle opening degree formula is obtained by combining a throttle control throttle equation and a speed density method equation.

[0013] In a possible implementation, the throttle opening degree formula is obtained by combining a throttle control throttle equation and a speed density method equation, including: S1. The throttle control throttle equation is as follows: ; Wherein, TPS is a throttle opening degree; k 0 is a correction coefficient based on air temperature, map Pd is a throttle downstream pressure, ptp Pup is a throttle upstream pressure, f ( map / ptp ) is a correction coefficient based on a throttle pressure ratio before and after the throttle, q m1 Q is an air flow through the throttle; S2. The throttle control speed density method equation is as follows: ; Wherein,q m2 is the air flow rate flowing into the engine cylinder, b is the EGR partial pressure and gas partial pressure, and a is the pressure-flow conversion coefficient; S3. According to the characteristics of the natural gas engine, the air flow through the throttle valve q m1 Equivalent to the air flow into the engine cylinder q m2 , combining the throttle control equation with the speed density method equation to obtain the following throttle opening formula: .

[0014] In a possible implementation, the target control mode is a torque control mode, and the target parameters corresponding to the torque control mode include: actual pre-throttle pressure ptp and set throttle valve pressure map_set .

[0015] In a possible implementation, the target control mode is a speed control mode, and the target parameters corresponding to the speed control mode include: the set pre-throttle pressure ptp_set and set throttle valve pressure map_set .

[0016] In a possible implementation, the apparatus further includes: The adaptive adjustment module is used to determine whether the absolute value of the difference between the actual value of the pressure in the manifold and the preset value is greater than a first limit after the pressure in the manifold is stabilized; if it is not greater than the first limit, no adjustment is required; if it is greater than the first limit, adjust a or b in the throttle opening formula according to the set pressure ratio before and after the throttle until the absolute value of the difference between the actual value of the pressure in the manifold and the preset value is no greater than the first limit.

[0017] In a possible implementation, the adaptive adjustment module is specifically configured to: According to the set pressure ratio before and after the throttle valve is greater than the second limit, a is reduced according to the first preset step size; According to the set pressure ratio before and after the throttle valve is not greater than the second limit value, b is increased according to the second preset step size.

[0018] In a third aspect, an embodiment of the present application provides an electronic device comprising: a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor implements the method described in the first aspect of the present application when executing the computer program.

[0019] In a fourth aspect, the embodiments of the present application provide a computer readable storage medium, having stored thereon computer readable instructions, which can be executed by a processor to implement the method of the first aspect of the present application.

[0020] The torque control method and device of the natural gas engine, the electronic device and the storage medium provided by the present application determine a target control mode required by the current natural gas engine, obtain a target parameter corresponding to the target control mode, input the target parameter into a preset throttle opening formula to obtain a target throttle opening, and control the torque of the natural gas engine according to the target throttle opening. The throttle opening formula is obtained by combining a throttle equation for throttle control and a speed-density method equation. Compared with the prior art, the throttle opening formula is obtained by combining the throttle equation for throttle control and the speed-density method equation according to the characteristics of the natural gas engine. For different target control modes, the throttle opening formula calculates the throttle opening by using different target parameters, so that the torque corresponding to the throttle opening can adapt to the target control mode, thereby improving the controllability of the natural gas engine. BRIEF DESCRIPTION OF DRAWINGS

[0021] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not intended to limit the scope of the present application. Moreover, the same reference numerals are used throughout the same figures. In the drawings: Figure 1 A flow chart of a torque control method of a natural gas engine is shown; Figure 2 A flow chart of a specific torque control method of a natural gas engine is shown; Figure 3 A schematic diagram of a torque control device of a natural gas engine is shown. DETAILED DESCRIPTION

[0022] Exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be accurately conveyed to those skilled in the art.

[0023] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the present application should be understood as their common meanings by those skilled in the art to which the present application belongs.

[0024] In addition, the terms "first" and "second" and the like are used to distinguish different objects, rather than to describe a particular order. Furthermore, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a list of steps or units is not limited to the listed steps or units, but can optionally further include other steps or units not listed, or can optionally further include other steps or units inherent to such processes, methods, products, or devices.

[0025] In order to achieve rapid control of the throttle pressure ratio or the throttle pressure after the throttle, and to improve the controllability of the engine torque, the embodiments of the present application provide a torque control method and device of a natural gas engine, an electronic device, and a computer readable storage medium, which are described below with reference to the accompanying drawings.

[0026] Please refer to Figure 1 , which shows a flowchart of a torque control method of a natural gas engine provided by the present application. As Figure 1 shown, the method includes the following steps: S101, determining a target control mode required by the current natural gas engine; Under different working conditions, the vehicle has different control mode requirements for the engine, for example, some working conditions require rapid control of the engine power, that is, rapid control of the engine torque, and some other working conditions require control of the engine control stability, that is, control of the engine speed. Therefore, the above target control mode can be a torque control mode or a speed control mode.

[0027] Specifically, the current engine torque demand state, speed control demand state and the like can be obtained, and the priority of the demand for power and the demand for control stability of the engine at this moment is comprehensively decided according to the above information, and the target control mode required by the current natural gas engine is determined according to the rule of higher priority.

[0028] S102, obtaining a target parameter corresponding to the target control mode; The control parameters of the natural gas engine include the throttle pressure before the throttle ptp , the throttle pressure after the throttle map_set , etc.

[0029] Specifically, the target parameter corresponding to the torque control mode provided by the present application includes the actual throttle pressure before the throttle ptp and the set throttle pressure after the throttle map_set .

[0030] Specifically, the target parameter corresponding to the speed control mode provided by the present application includes the set throttle pressure before the throttle ptp_set and the set throttle pressure after the throttlemap_set .

[0031] S103, input the target parameter into a preset throttle opening degree formula to obtain a target throttle opening degree; The throttle opening degree formula is obtained by combining a throttle equation for throttle control and a speed-density method equation, and the specific process is as follows: S1, according to the sensor configuration of an existing natural gas engine, the throttle equation for throttle control is as follows: ; Wherein, TPS is the throttle opening degree; k 0 is a correction coefficient based on air temperature, map is the pressure after the throttle, ptp is the pressure before the throttle; f ( map / ptp ) is a correction coefficient based on the ratio of the pressure before and after the throttle, which is obtained by table lookup; q m1 is the air flow through the throttle.

[0032] S2, the speed-density method equation for throttle control is as follows: ; Wherein, q m2 is the air flow into the engine cylinder, map is the pressure after the throttle; b is the EGR partial pressure and the fuel gas partial pressure, which is measured by the fuel gas flow and EGR flow sensors; a is the pressure flow conversion coefficient, which is related to the engine speed, displacement and charge coefficient and other parameters, and the specific value is obtained by table lookup; EGR represents the exhaust gas recirculation system.

[0033] S3, according to the characteristics of the natural gas engine, the air flow through the throttle q m1 is equivalent to the air flow into the engine cylinder q m2 The throttle equation for throttle control is combined with the speed-density method equation to obtain the following throttle opening degree formula: .

[0034] Specifically, the target parameters corresponding to the torque control mode include: the actual pressure before the throttle ptp and the set pressure after the throttle map_set , then the above throttle opening degree formula is transformed as follows: ; In the power driving, the above throttle opening degree formula is based on the actual pressure before the throttleptp and the set throttle back pressure map_set The throttle opening degree required is calculated, because when the power requirement is required, the throttle opening degree obtained with the actual throttle front pressure ptp as the reference is insufficient or excessive, the throttle can be quickly adjusted to ensure that the throttle back pressure ptp is consistent with the actual value. map

[0035] Specifically, the target parameters corresponding to the speed control mode include: the set throttle front pressure ptp_set and the set throttle back pressure map_set The throttle opening degree formula is transformed as follows: ; When the speed control requirement is required, the ptp / map in the throttle opening degree formula is replaced by the set pressure ratio, at this time, the throttle will respond to the pressure ratio before and after the throttle, at this time, the throttle opening degree is less affected by the actual pressure parameters in the external environment, and thus in the process of controlling the torque of the engine to control the speed, the change of the throttle is less affected by the surrounding parameters, and the final output throttle opening degree is more stable.

[0036] It is found through experiments that the latter part of the throttle opening degree formula has a very small influence on the final throttle opening degree, because the b parameter is very different from the throttle back pressure map , and thus in some embodiments, the latter part of the throttle opening degree formula can be omitted to simplify the calculation.

[0037] It can be seen that the throttle control throttle equation is combined with the speed density method equation in the present application, the control of the manifold pressure and the pressure ratio before and after the throttle is realized, the original rigid throttle control mode is changed to a more flexible throttle control mode, the corresponding throttle opening degree is output under different throttle control requirements, and the controllability of the engine torque is improved.

[0038] S104, controlling the torque of the natural gas engine according to the target throttle opening degree.

[0039] On the basis of the throttle opening degree formula, the required intake amount is obtained based on the required torque table, the required throttle back pressure is obtained by inversely calculating the above speed density method equation according to the required torque and the required set throttle front pressure and back pressure ratio is obtained by looking up the required torque table, and the required throttle front pressure is obtained according to the required throttle back pressure / the required set throttle front pressure and back pressure ratio, which is used for closed-loop control of the supercharger.

[0040] ​In some embodiments, the torque control method of the natural gas engine provided by the present application further comprises the following steps: after the manifold pressure is stabilized, determining whether the absolute value of the difference between the actual value and the preset value of the manifold pressure is greater than a first limit value; if the absolute value is not greater than the first limit value, no adjustment is needed; if the absolute value is greater than the first limit value, adjusting a or b in the throttle opening degree formula according to the throttle pressure ratio until the absolute value of the difference between the actual value and the preset value of the manifold pressure is not greater than the first limit value. The first limit value can be set according to actual conditions.

[0041] Specifically, the adjusting a or b in the throttle opening degree formula according to the throttle pressure ratio comprises: according to the throttle pressure ratio being greater than a second limit value, decreasing a by a first preset step; and according to the throttle pressure ratio being not greater than the second limit value, increasing b by a second preset step. The second limit value can be set according to actual conditions.

[0042] That is, after the manifold pressure is stabilized, it is determined whether the absolute value of the difference between the actual value and the preset value of the manifold pressure is greater than a first limit value; if the absolute value is not greater than the first limit value, it indicates that the throttle control is accurate and no adjustment is needed; if the absolute value is greater than the first limit value, it indicates that the throttle control is inaccurate and adjustment is needed. The adjustment method is: if the throttle pressure ratio is greater than a second limit value, a in the formula is a+step0; if the throttle pressure ratio is less than the second limit value, b in the formula is b+step1; step0 is a negative value and step1 is a positive value. map_set / ptp_set map_set / ptp_set

[0043] For the convenience of understanding, the present application further provides a specific flow chart of the torque control method of the natural gas engine as shown in Figure 2

[0044] The torque control method of the natural gas engine provided by the present application determines the target control mode required by the current natural gas engine, obtains the target parameter corresponding to the target control mode, inputs the target parameter into a preset throttle opening degree formula to obtain a target throttle opening degree, and controls the torque of the natural gas engine according to the target throttle opening degree. The throttle opening degree formula is obtained by combining the throttle control equation and the speed density method equation. Compared with the prior art, the present application combines the throttle control equation and the speed density method equation according to the characteristics of the natural gas engine to obtain the throttle opening degree formula. For different target control modes, the throttle opening degree formula calculates the throttle opening degree by using different target parameters, so that the torque corresponding to the throttle opening degree can adapt to the target control mode, thereby improving the controllability of the natural gas engine.

[0045] ​​​In the above-mentioned embodiments, a torque control method of a natural gas engine is provided, and correspondingly, a torque control device of a natural gas engine is also provided, which can be implemented by software, hardware or a combination of software and hardware. For example, the torque control device of the natural gas engine can include integrated or separate functional modules or units to perform the corresponding steps in the above-mentioned methods. Please refer to Figure 3 FIG. 1 shows a schematic diagram of a torque control device of a natural gas engine according to some embodiments of the present application. Since the device embodiments are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the part of the description of the method embodiments. The device embodiments described below are only schematic.

[0046] As shown in Figure 3 , the torque control device 10 of the natural gas engine can include: a determination module 101 configured to determine a target control mode required by a current natural gas engine; an acquisition module 102 configured to acquire a target parameter corresponding to the target control mode; a calculation module 103 configured to input the target parameter into a preset throttle opening degree formula to obtain a target throttle opening degree; a control module 104 configured to control the torque of the natural gas engine according to the target throttle opening degree; wherein the throttle opening degree formula is obtained by combining a throttle equation for throttle control and a speed-density method equation.

[0047] In a possible implementation, the throttle opening degree formula is obtained by combining a throttle equation for throttle control and a speed-density method equation, including: S1, the throttle equation for throttle control is as follows: ; wherein TPS is the throttle opening degree; k 0 is a correction coefficient based on air temperature, map Pth is the pressure after the throttle, ptp Pth is the pressure before the throttle, f ( map / ptp ) is a correction coefficient based on the ratio of the pressure before and after the throttle, q m1 Q is the air flow through the throttle; S2, the speed-density method equation for throttle control is as follows: ; wherein, q m2is the air flow rate flowing into the engine cylinder, b is the EGR partial pressure and the fuel gas partial pressure, and a is the pressure-flow conversion coefficient; S3. According to the characteristics of natural gas engines, the air flow through the throttle valve q m1 Equivalent to the air flow into the engine cylinder q m2 , combining the throttle control equation with the speed density method equation to obtain the following throttle opening formula: .

[0048] In a possible implementation, the target control mode is a torque control mode, and the target parameters corresponding to the torque control mode include: actual pre-throttle pressure ptp and set throttle valve pressure map_set .

[0049] In a possible implementation, the target control mode is a speed control mode, and the target parameters corresponding to the speed control mode include: the set pre-throttle pressure ptp_set and set throttle valve pressure map_set .

[0050] In a possible implementation, the apparatus further includes: The adaptive adjustment module is used to determine whether the absolute value of the difference between the actual value of the pressure in the manifold and the preset value is greater than a first limit after the pressure in the manifold is stabilized; if it is not greater than the first limit, no adjustment is required; if it is greater than the first limit, adjust a or b in the throttle opening formula according to the set pressure ratio before and after the throttle until the absolute value of the difference between the actual value of the pressure in the manifold and the preset value is no greater than the first limit.

[0051] In a possible implementation, the adaptive adjustment module is specifically configured to: According to the set pressure ratio before and after the throttle valve is greater than the second limit, a is reduced according to the first preset step size; According to the set pressure ratio before and after the throttle valve is not greater than the second limit value, b is increased according to the second preset step size.

[0052] The torque control device of the natural gas engine provided by the embodiment of the present application determines a target control mode required by the current natural gas engine, acquires a target parameter corresponding to the target control mode, inputs the target parameter into a preset throttle opening formula to obtain a target throttle opening, and controls the torque of the natural gas engine according to the target throttle opening. The throttle opening formula is obtained by combining a throttle equation for throttle control and a speed-density method equation according to the characteristics of the natural gas engine. Compared with the prior art, the throttle opening formula is obtained by combining the throttle equation for throttle control and the speed-density method equation according to the characteristics of the natural gas engine. For different target control modes, the throttle opening formula calculates the throttle opening by using different target parameters, so that the torque corresponding to the throttle opening can adapt to the target control mode, thereby improving the controllability of the natural gas engine.

[0053] The embodiment of the present application also provides an electronic device corresponding to the torque control method of the natural gas engine provided in the foregoing embodiments. The electronic device can be a gearbox electronic control unit, a mobile phone, a notebook computer, a tablet computer, a desktop computer, or the like, to execute the torque control method of the natural gas engine.

[0054] The electronic device provided by the embodiment of the present application and the torque control method of the natural gas engine provided by the embodiment of the present application are based on the same inventive concept and have the same beneficial effects as the method adopted, run or implemented by the electronic device and the torque control method of the natural gas engine.

[0055] The embodiment of the present application also provides a computer readable storage medium corresponding to the torque control method of the natural gas engine provided in the foregoing embodiments, which stores a computer program (i.e., a program product). When the computer program is run by a processor, the torque control method of the natural gas engine provided by any of the foregoing embodiments is executed.

[0056] It should be noted that examples of the computer readable storage medium can also include, but are not limited to, a phase change memory (PRAM), a static random access memory (SRAM), a dynamic random access memory (DRAM), other types of random access memory (RAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory or other optical or magnetic storage medium, which will not be described one by one here.

[0057] The computer readable storage medium provided by the above embodiments of the present application and the torque control method of the natural gas engine provided by the embodiments of the present application are based on the same inventive concept and have the same beneficial effects as the method adopted, run or implemented by the application program stored in the computer readable storage medium.

[0058] It should be noted that the flowchart and block diagrams in the drawings show architectural, functional and chronological arrangement of systems, methods and computer program products according to the embodiments of the present application. In this regard, each block in the flowchart or block diagrams can represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the flowchart or block diagrams can occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently or the blocks can sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and / or flowchart illustrations, and combinations thereof, can be implemented by a dedicated hardware-based system that performs the specified functions or acts or combinations of special-purpose hardware and computer instructions.

[0059] Finally, it should be noted that the above-described embodiments are merely intended to illustrate the technical solutions of the present application, but not to limit the same; even though the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features thereof can be replaced by equivalent replacements; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and should be included in the scope of the claims and the specification of the present application.

Claims

1. A torque control method for a natural gas engine, characterized in that: include: Determine the target control mode for current natural gas engine requirements; Obtaining target parameters corresponding to the target control mode; Inputting the target parameter into a preset throttle opening formula to obtain a target throttle opening; controlling the torque of the natural gas engine according to the target throttle opening; The throttle opening formula is obtained by combining the throttle equation for throttle control with the speed density method equation.

2. The torque control method of a natural gas engine according to claim 1, characterized in that: The throttle opening formula is obtained by combining the throttle equation for throttle control with the speed density method equation, and includes: S1. The throttle equation for throttle control is as follows: ； Among them, TPS is the throttle opening; k 0 is the correction factor based on air temperature, map is the pressure after the throttle valve, ptp is the pressure before the throttle valve, f ( map / ptp ) is the correction coefficient based on the pressure ratio before and after the throttle valve, q m1 is the air flow through the throttle valve; S2. The speed density method equation for throttle control is as follows: ； in, q m2 is the air flow rate flowing into the engine cylinder, b is the EGR partial pressure and the fuel gas partial pressure, and a is the pressure-flow conversion coefficient; S3. According to the characteristics of natural gas engines, the air flow through the throttle valve q m1 Equivalent to the air flow into the engine cylinder q m2 , combining the throttle control equation with the speed density method equation to obtain the following throttle opening formula: 。 3. The torque control method of a natural gas engine according to claim 2, characterized in that: The target control mode is the torque control mode. The target parameters corresponding to the torque control mode include: the actual pre-throttle pressure ptp and set throttle valve pressure map_set .

4. The torque control method of a natural gas engine according to claim 2, characterized in that: The target control mode is the speed control mode, and the target parameters corresponding to the speed control mode include: the set pre-throttle pressure ptp_set and set throttle valve pressure map_set .

5. The torque control method of a natural gas engine according to claim 2, characterized in that: The method further comprises: After the pressure in the manifold is stable, determining whether the absolute value of the difference between the actual value of the pressure in the manifold and the preset value is greater than a first limit; If it is not greater than the first limit, no adjustment is required; If it is greater than the first limit, adjust a or b in the throttle opening formula according to the set pressure ratio before and after the throttle until the absolute value of the difference between the actual value of the pressure in the manifold and the preset value is no greater than the first limit.

6. The torque control method of a natural gas engine according to claim 5, characterized in that: The method of adjusting a or b in the throttle opening formula according to the set pressure ratio before and after the throttle includes: According to the set pressure ratio before and after the throttle valve is greater than the second limit, a is reduced according to the first preset step size; According to the set pressure ratio before and after the throttle valve is not greater than the second limit value, b is increased according to the second preset step size.

7. A torque control device for a natural gas engine, characterized in that: include: a determination module, for determining a target control mode currently required by the natural gas engine; An acquisition module, configured to acquire target parameters corresponding to the target control mode; a calculation module, configured to input the target parameter into a preset throttle opening formula to obtain a target throttle opening; a control module, configured to control the torque of the natural gas engine according to the target throttle opening; The throttle opening formula is obtained by combining the throttle equation for throttle control with the speed density method equation.

8. The torque control device for a natural gas engine according to claim 7, characterized in that: The throttle opening formula is obtained by combining the throttle equation for throttle control with the speed density method equation, and includes: S1. The throttle equation for throttle control is as follows: ； Among them, TPS is the throttle opening; k 0 is the correction factor based on air temperature, map is the pressure after the throttle valve, ptp is the pressure before the throttle valve, f ( map / ptp ) is the correction coefficient based on the pressure ratio before and after the throttle valve, q m1 is the air flow through the throttle valve; S2. The speed density method equation for throttle control is as follows: ； in, q m2 is the air flow rate flowing into the engine cylinder, b is the EGR partial pressure and the fuel gas partial pressure, and a is the pressure-flow conversion coefficient; S3. According to the characteristics of natural gas engines, the air flow through the throttle valve q m1 Equivalent to the air flow into the engine cylinder q m2 , combining the throttle control equation with the speed density method equation to obtain the following throttle opening formula: 。 9. An electronic device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method according to any one of claims 1 to 6 when executing the computer program.

10. A computer-readable storage medium, characterized in that Computer-readable instructions are stored thereon, and the computer-readable instructions can be executed by a processor to implement the method according to any one of claims 1 to 6.

Images