Cooperative control method for glow plug and in-cylinder oil injection quantity in cold starting process of diesel engine

Abstract

The invention discloses a cooperative control method for a glow plug and a fuel injection quantity in a cylinder in a cold starting process of a diesel engine, which relates to the technical field of cold starting of diesel engines and comprises the following steps: firstly, judging a cold starting condition, and calculating the fuel injection quantity required by the glow plug according to a starting stage (an injection starting period / Ramp period); secondly, through iterative calculation, the final oil injection quantity of the glow plug and the air inlet oxygen content decline value caused by the final oil injection quantity are synchronously determined, and then the effective oxygen mass capable of being used for in-cylinder combustion is obtained; and finally, accurately calculating and executing the in-cylinder fuel injection quantity after collaborative correction according to the effective oxygen mass. According to the method, dynamic accurate matching of the preheating process and the oil injection process is achieved, the first-time starting success rate and the starting speed of the low-compression-ratio and high-supercharge-ratio diesel engine in the low-temperature environment are remarkably increased, and smoking and pollutant emission in the cold starting stage are effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of diesel engine cold start technology, specifically to a method for coordinated control of the glow plug and in-cylinder fuel injection quantity during the cold start process of a diesel engine, which is particularly suitable for the cold start process of a low compression ratio, high boost ratio diesel engine in a low temperature environment. Background Technology

[0002] Diesel engines rely on compression ignition, and their cold-start performance is heavily dependent on the cylinder temperature and pressure at the end of compression. For modern high-performance diesel engines with low compression ratios designed to achieve higher thermal efficiency and lower friction losses, as well as diesel engines with high boost ratio turbochargers, the end-of-compression temperature is difficult to reach the auto-ignition temperature of diesel fuel during cold starts in low-temperature environments. This results in difficulty starting, white smoke, incomplete combustion, or even failure to start.

[0003] Currently, intake preheating devices (such as glow plugs) are widely used to increase intake air temperature, thereby raising the in-cylinder temperature at the end of compression. Traditional glow plug control strategies typically rely on coolant or intake air temperature, using fixed or simple lookup table methods for on / off control. However, this strategy has significant shortcomings: the glow plug is essentially a small burner located in the intake manifold or cylinder preheating chamber, injecting and igniting a small amount of diesel fuel during operation. This means that the working fluid flowing through the glow plug into the cylinder is not pure air, but a mixture of air and the combustion products of the diesel fuel injected by the glow plug. The oxygen concentration, specific heat capacity, and other thermophysical properties of this mixture differ from those of fresh air.

[0004] Current technology ignores the aforementioned key changes and still calculates and controls the in-cylinder fuel injection quantity based on the assumption of pure air. This results in the actual amount of oxygen entering the cylinder when the glow plug is working potentially being lower than the preset value. If the original fuel injection quantity is still applied, the in-cylinder mixture will be too rich, combustion will be poor, and the generation of soot and unburned hydrocarbons will be increased. This not only reduces the success rate of cold starts but also exacerbates emissions pollution during the start-up phase. Therefore, there is an urgent need for a control method that can comprehensively consider the working state of the glow plug and dynamically adjust the in-cylinder fuel injection quantity accordingly. Summary of the Invention

[0005] This invention aims to provide a method for coordinated control of the glow plug and in-cylinder fuel injection quantity during the cold start process of a diesel engine, in order to overcome the problem of disconnect between the operation of the glow plug and the control of the in-cylinder fuel injection quantity in the existing cold start preheating control of diesel engines. It provides a method that can accurately coordinate and control the in-cylinder fuel injection quantity according to the combustion state of the glow plug, so as to optimize the cold start performance of low compression ratio and high boost ratio diesel engines, improve the start success rate, and reduce smoke and emissions.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for coordinated control of glow plug and in-cylinder fuel injection quantity during the cold start process of a diesel engine includes the following steps:

[0008] S1. Cold Start Judgment and Stage Division: When the engine temperature is below the threshold, the system enters cold start mode, dividing the cold start process into two stages with different physical characteristics:

[0009] Initiation phase: The stage where the engine is towed until it successfully ignites for the first time, establishing initial ignition conditions;

[0010] Ramp phase: The stage from initial ignition until the engine speed stabilizes at idle, maintaining stable combustion;

[0011] S2: Preheating demand calculation and fuel injection: Based on the current stage, ambient temperature and engine speed, calculate the minimum required intake air temperature and fuel injection quantity of the glow plug based on the preset physical model, and control the operation of the glow plug.

[0012] S3: Cooperative Iterative Calculation Based on Oxygen Balance: Initiate an iterative calculation process to simultaneously determine the final glow plug injection quantity and the oxygen content of the preheated intake air. The iterative calculation logic includes:

[0013] a. Input: Initial oxygen content (21%), target ignition conditions, engine parameters;

[0014] b. Calculation: Under the current assumed oxygen content, calculate the preheating power required to meet the ignition conditions and the corresponding preheating plug fuel injection quantity;

[0015] c. Update: Based on the calculated fuel injection quantity of the glow plug, the oxygen consumed by the glow plug combustion is deduced, thereby updating the predicted intake oxygen content value;

[0016] d. Iteration: Using the updated oxygen content as the new input, repeat the above calculation steps a~c until the change in oxygen content converges to a stable value, and output the final glow plug injection quantity and the final intake oxygen content after convergence.

[0017] S4: Cooperative in-cylinder injection quantity calculation and execution: Based on the final intake oxygen content obtained in step S3, calculate the effective oxygen mass available for in-cylinder combustion, and then combine it with the cold start target air-fuel ratio to calculate the cooperative in-cylinder injection quantity that is precisely matched with the current preheating state, and execute the injection operation.

[0018] Step 5: Result Judgment and Adaptive Processing: Monitor the starting result; if successful, switch to or exit the cold start mode according to the stage; if unsuccessful, within the safety limits, adaptively increase the fuel injection quantity of the glow plug and recalculate, and try again.

[0019] Furthermore, the temperature threshold satisfies one of the following conditions:

[0020] (1) Coolant temperature is below 10℃;

[0021] (2) The external temperature of the engine is below 5°C.

[0022] Furthermore, the conditions for the stage division are as follows:

[0023] If engine speed If there are no signs of ignition, it is determined to be the initial spraying stage; if there is intermittent ignition but the rotation speed is not stable, it is determined to be the Ramp stage.

[0024] Furthermore, different minimum intake temperature calculation models were established for the initial spraying period and the ramp period to more accurately reflect the thermodynamic state at different stages.

[0025] Furthermore, the calculation models for the minimum intake air temperature during the initial spray and ramp phases include:

[0026]

[0027] in, This is the minimum intake air temperature during the initial spraying period. This is the lowest intake temperature during the Ramp phase. This is the base value for calculating the initial spraying period. For fuels with low calorific value, take .

[0028] Furthermore, the engine's minimum intake air temperature The calculations based on the model that satisfies the target ignition delay condition include:

[0029]

[0030] in:

[0031]

[0032]

[0033]

[0034]

[0035] in, The stroke of a diesel engine is measured in millimeters (mm). Engine speed, in rpm; To account for the energy loss coefficient after air leakage and heat dissipation; Intake pressure, unit: bar; Intake air temperature, in Kelvin (K). This refers to the compression ratio; The adiabatic coefficient is taken as 1.4; The universal gas constant is taken as 8.314;

[0036] By solving (generally )get .

[0037] Furthermore, the change in oxygen content after the glow plug starts working is calculated using oxygen balance, including:

[0038]

[0039] in, For the combustion efficiency of the glow plug, The intake air mass flow rate is expressed in kg / s. This refers to the fuel injection rate for the glow plug, expressed in kg / s.

[0040] Furthermore, the calculation and execution of the in-cylinder fuel injection quantity includes the following steps:

[0041] 1) Estimate the intake mass flow rate of air for each cycle. ;

[0042] 2) Obtain the target air-fuel ratio ;

[0043] 3) Calculate the corrected air-fuel ratio: ;

[0044] 4) Calculate the target equivalent ratio: ;

[0045] 5) Calculate the in-cylinder fuel injection quantity: ;

[0046] 6) Convert it into an injector pulse width signal to control the injector actuator to perform the injection operation.

[0047] Furthermore, when implementing the control method, a full-condition range of basic values ​​based on a MATLAB physical model is generated through offline calculation. The data is then stored in the ROM of the electronic control unit (ECU) in the form of a two-dimensional or three-dimensional table. When the system is under actual control, the accurate value of the current condition is obtained through bilinear interpolation.

[0048] The principles and beneficial effects of this technical solution include at least the following:

[0049] Achieving precise and coordinated control at the physical level: For the first time, the glow plug system is modeled as a "pre-burner" that consumes both oxygen and fuel. By calculating the key variable of "effective oxygen mass" in real time, the in-cylinder fuel injection quantity is dynamically and accurately adjusted. This method fundamentally solves the problem of overly rich air-fuel mixture caused by the disconnect between preheating and fuel injection control.

[0050] For the cold start phase, precise control is implemented: the cold start process is divided into the spraying period and the ramp period. Based on the physical characteristics and control objectives of different stages, corresponding calculation models and control parameters are adopted, thereby significantly improving the accuracy of control and adaptability to operating conditions.

[0051] Significantly improves cold start performance and system robustness: By combining the optimal target air-fuel ratio calibrated on the bench with real-time estimated in-cylinder oxygen content, the system ensures that the in-cylinder mixture is always within the optimal ignition concentration range, greatly improving the first-start success rate and start-up speed under extreme conditions. The system's built-in adaptive failure handling mechanism further enhances fault tolerance and operational robustness.

[0052] Effectively reduces cold start emissions: By avoiding incomplete combustion caused by oxygen estimation errors, it can significantly reduce white smoke, soot, and unburned hydrocarbons generated during the cold start phase, resulting in outstanding environmental benefits.

[0053] Balancing theoretical completeness with engineering practicality: This scheme indirectly encompasses the influence of exhaust gas on complex coupled factors such as ignition temperature through calibrated MAP diagrams. The core algorithm is simple, reliable, and easy to implement. Simultaneously, the system retains interfaces for further optimization based on the model, balancing real-time control requirements with the potential for continuous improvement in control accuracy. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of a method for coordinated control of the glow plug and in-cylinder fuel injection quantity during the cold start process of a diesel engine.

[0055] Figure 2 A MAP plot showing the effect of engine speed and ambient temperature on minimum intake air temperature;

[0056] Figure 3 A MAP plot showing the effect of engine speed and ambient temperature on minimum preheating power;

[0057] Figure 4 A MAP plot showing the effect of engine speed and ambient temperature on the final oxygen content entering the engine cylinder.

[0058] Figure 5 A MAP plot showing the effect of engine speed and ambient temperature on the fuel injection quantity of the glow plug.

[0059] Figure 6 This is a MAP diagram showing the effect of engine speed and ambient temperature on the amount of fuel injected into the cylinder. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. Here, the illustrative embodiments and descriptions of this invention are used to explain the invention, but are not intended to limit the invention.

[0061] It should also be noted that, in order to avoid obscuring the invention with unnecessary details, only the structures and / or processing steps closely related to the solution according to the invention are shown in the accompanying drawings, while other details that are not closely related to the invention are omitted.

[0062] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, element, step, or component, but does not exclude the presence or addition of one or more other features, elements, steps, or components.

[0063] In the following description, embodiments of the invention will be illustrated with reference to the accompanying drawings. In the drawings, the same reference numerals represent the same or similar parts, or the same or similar steps.

[0064] It should be emphasized here that the step markers mentioned below are not a limitation on the order of the steps, but should be understood as meaning that the steps can be executed in the order mentioned in the embodiments, or in a different order than in the embodiments, or several steps can be executed simultaneously.

[0065] Example 1

[0066] I. System Composition and Working Principle

[0067] The hardware system required for implementing this invention includes:

[0068] - Diesel engine, equipped with intake glow plug;

[0069] - Electronic control unit (ECU), which has data processing and control output functions;

[0070] - Temperature sensor group: including coolant temperature sensor, intake air temperature sensor, and ambient temperature sensor;

[0071] - Pressure sensor: Intake pressure sensor;

[0072] - Speed ​​and position sensors: crankshaft position sensor, camshaft position sensor;

[0073] - Actuators: preheating plug fuel supply valve, in-cylinder fuel injector.

[0074] II. Implementation Details of Control Methods

[0075] Please see Figure 1 The cooperative control method of the present invention is implemented in the ECU according to the following process:

[0076] S1. Cold start condition monitoring and stage judgment

[0077] After the engine is powered on, the ECU continuously monitors the signals from various temperature sensors. When the coolant temperature... or ambient temperature When the engine enters cold start mode, the current stage is determined based on the engine's current speed and ignition status.

[0078] - If engine speed And there were no signs of fire, so it was determined to be the initial spraying stage;

[0079] - If there is intermittent ignition but the engine speed is not stable, it is determined to be the Ramp period.

[0080] S2. Calculation of basic parameters based on physical model

[0081] The ECU calls the corresponding calculation model based on the current stage:

[0082] 1) Based on the current ambient temperature and engine speed Query Figure 2 The minimum intake air temperature MAP shown provides the basic data. ;

[0083] 2) Based on engine speed n and Query Figure 5 The initial fuel injection quantity (MAP) of the glow plug is shown below. ;

[0084] S3, Preheat plug activation and iterative collaborative calculation

[0085] The ECU controls the glow plug to be energized and injects the initial amount of fuel, while simultaneously initiating iterative calculations:

[0086] 1) Let the iteration number k=0, and the initial oxygen content be... ;

[0087] 2) Enter the iterative loop:

[0088] a. According to the current situation Based on engine parameters, calculate the minimum intake air temperature under the current oxygen content. ;

[0089] b. Calculate the corresponding preheating power and the updated glow plug injection volume ;

[0090] c. Based on air mass flow estimation and Calculate the new oxygen content ;

[0091] d. If or The iteration ends;

[0092] e. Otherwise, , Return to step a;

[0093] 3) Output the final value: , ;

[0094] 4) The ECU adjusts the fuel injection quantity of the glow plug to .

[0095] S4, Calculation of Cooperative In-Cylinder Injection Quantity

[0096] 1) Estimate the intake mass flow rate of air for each cycle. ;

[0097] 2) Obtain the target air-fuel ratio Based on the current stage and temperature, consult the relevant MAP. The determination of the target air-fuel ratio can be found in the existing literature: Study on non-monotonic variation of a HDE cold-start withcycle fuel injection quantity in the critical ambient temperature of compression ignition.

[0098] In P8, it shows the relationship between different cyclic injection quantities and cold start success rate and cold start time determined by experiments. Based on its research, the equivalent ratio (1.2) corresponding to its optimal injection quantity is selected as the target equivalent ratio.

[0099] 3) Calculate the corrected air-fuel ratio: ;

[0100] 4) Calculate the target equivalent ratio: ;

[0101] 5) Calculate the in-cylinder fuel injection quantity: ;

[0102] 6) Convert to injector pulse width signal.

[0103] S5. Fuel Injection Execution and Result Monitoring

[0104] When the engine speed reaches the injection threshold (injection period: 200 rpm, ramp period: 400 rpm) and the crankshaft position is appropriate, the ECU triggers the injector of the target cylinder to inject fuel. Then monitor the speed change:

[0105] If the engine speed continues to rise above the success threshold (initial spray phase: 400 rpm, Ramp phase: 800 rpm), the stage is considered successful.

[0106] If the rotational speed does not respond or decreases, it is considered a failure and enters adaptive processing.

[0107] S6, Adaptive Failure Handling

[0108] 1) Increment the failure counter by 1: ;

[0109] 2) If :

[0110] a. Increase the fuel injection quantity of the glow plug based on the number of failures:

[0111] ;

[0112] b. Fine-tune the target air-fuel ratio: ;

[0113] c. Return to step 203 and recalculate;

[0114] 3) If :

[0115] a. Stop all operations;

[0116] b. Record the fault code "P0F20 - Cold start failure";

[0117] c. Prompt the user via the instrument;

[0118] d. Wait for the ignition switch to reset.

[0119] III. Detailed Explanation of Key Parameter Calculation Model

[0120] 3.1 Calculation Model for Diesel Ignition Delay Angle

[0121] Minimum intake air temperature of the engine Calculations were performed using a model that satisfies the target ignition delay condition:

[0122]

[0123] in:

[0124]

[0125]

[0126]

[0127]

[0128] The stroke of a diesel engine is measured in millimeters (mm). Engine speed, in rpm; To account for the energy loss coefficient after air leakage and heat dissipation; Intake pressure, unit: bar; Intake air temperature, in Kelvin (K). This refers to the compression ratio; The adiabatic coefficient is taken as 1.4; The universal gas constant is taken as 8.314.

[0129] By solving (usually) To obtain the lowest intake air temperature .

[0130] 3.2 Calculation model for minimum inlet air temperature during the initial spray and ramp phases

[0131]

[0132] in, This is the minimum intake air temperature during the initial spraying period. This is the lowest intake temperature during the Ramp phase. This is the base value for calculating the initial spraying period. For fuels with low calorific value, take .

[0133] 3.3 Iterative Calculation Model for Oxygen Content

[0134] The change in oxygen content after the glow plug starts working is calculated using oxygen balance:

[0135]

[0136] in, For the combustion efficiency of the glow plug, The intake air mass flow rate is expressed in kg / s. This refers to the fuel injection rate for the glow plug, expressed in kg / s.

[0137] IV. Generation and Application of Calibration MAP

[0138] The various MAP diagrams described in this invention (please refer to the specific ones) Figures 2 to 6 Generated through offline calculation:

[0139] 1) Calculate the basic values ​​for the entire operating condition range based on the MATLAB physical model;

[0140] 2) Store the data in the ECU's ROM in the form of a two-dimensional or three-dimensional table;

[0141] 3) In actual control, the accurate value of the current operating condition is obtained through bilinear interpolation.

[0142] Figures 2 to 6 The MAP diagrams shown illustrate the various parameters (minimum intake air temperature, minimum preheating power, final oxygen content, glow plug injection quantity, and in-cylinder injection quantity) required to ensure reliable cold starts at different ambient temperatures (-40°C to 20°C) and engine speeds (200-800 rpm). These diagrams provide a basic reference for control strategies, which are then dynamically corrected through iterative calculations in actual control.

[0143] Those skilled in the art will understand that the exemplary components, systems, and methods described in conjunction with the embodiments disclosed herein can be implemented in hardware, software, or a combination of both. Whether implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this invention. When implemented in hardware, it can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this invention are programs or code segments used to perform the desired tasks. The programs or code segments can be stored in a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried in a carrier wave.

[0144] It should be clarified that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of the present invention.

[0145] In this invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or in place of features of other embodiments.

[0146] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, various modifications and variations of the embodiments of the present invention are possible. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for coordinated control of the glow plug and in-cylinder fuel injection quantity during the cold start process of a diesel engine, characterized in that, Includes the following steps: S1. Cold Start Judgment and Stage Division: When the engine temperature is below the threshold, the system enters cold start mode, dividing the cold start process into two stages with different physical characteristics: Initiation phase: The stage where the engine is towed until it successfully ignites for the first time, establishing initial ignition conditions; Ramp phase: The stage from initial ignition until the engine speed stabilizes at idle, maintaining stable combustion; S2: Preheating demand calculation and fuel injection: Based on the current stage, ambient temperature and engine speed, calculate the minimum required intake air temperature and fuel injection quantity of the glow plug based on the preset physical model, and control the operation of the glow plug. S3: Cooperative Iterative Calculation Based on Oxygen Balance: Initiate an iterative calculation process to simultaneously determine the final glow plug injection quantity and the oxygen content of the preheated intake air. The iterative calculation logic includes: a. Input: Initial oxygen content (21%), target ignition conditions, engine parameters; b. Calculation: Under the current assumed oxygen content, calculate the preheating power required to meet the ignition conditions and the corresponding preheating plug fuel injection quantity; c. Update: Based on the calculated fuel injection quantity of the glow plug, the oxygen consumed by the glow plug combustion is deduced, thereby updating the predicted intake oxygen content value; d. Iteration: Using the updated oxygen content as the new input, repeat the calculation steps a~c above until the change in oxygen content converges to a stable value, and output the final glow plug injection quantity and the final intake oxygen content after convergence. S4: Cooperative in-cylinder injection quantity calculation and execution: Based on the final intake oxygen content obtained in step S3, calculate the effective oxygen mass available for in-cylinder combustion, and then combine it with the cold start target air-fuel ratio to calculate the cooperative in-cylinder injection quantity that is precisely matched with the current preheating state, and execute the injection operation. Step 5: Result Judgment and Adaptive Processing: Monitor the starting result; if successful, switch to or exit the cold start mode according to the stage; if unsuccessful, within the safety limits, adaptively increase the fuel injection quantity of the glow plug and recalculate, and try again.

2. The method for coordinated control of the glow plug and in-cylinder fuel injection quantity during the cold start process of a diesel engine according to claim 1, characterized in that, The temperature threshold is subject to one of the following conditions: (1) Coolant temperature is below 10℃; (2) The external temperature of the engine is below 5°C.

3. The method for coordinated control of the glow plug and in-cylinder fuel injection quantity during the cold start process of a diesel engine according to claim 1, characterized in that, The conditions for the stage division are as follows: If engine speed If there are no signs of ignition, it is determined to be the initial spraying stage; if there is intermittent ignition but the rotation speed is not stable, it is determined to be the Ramp stage.

4. The method for coordinated control of the glow plug and in-cylinder fuel injection quantity during the cold start process of a diesel engine according to claim 1, characterized in that, In step S2, different minimum intake temperature calculation models were established for the spray initiation period and the ramp period to more accurately reflect the thermodynamic state at different stages.

5. The method for coordinated control of the glow plug and in-cylinder fuel injection quantity during the cold start process of a diesel engine according to claim 4, characterized in that, The calculation models for the minimum intake air temperature during the initial spray and ramp phases include: in, This is the minimum intake air temperature during the initial spraying period. This is the lowest intake temperature during the Ramp phase. This is the base value for calculating the initial spraying period. For fuels with low calorific value, take .

6. The method for coordinated control of the glow plug and in-cylinder fuel injection quantity during the cold start process of a diesel engine according to claim 1, characterized in that, Minimum intake air temperature of the engine The calculations based on the model that satisfies the target ignition delay condition include: in: in, The stroke of a diesel engine is measured in millimeters (mm). Engine speed, in rpm; To account for the energy loss coefficient after air leakage and heat dissipation; Intake pressure, unit: bar; Intake air temperature, in Kelvin (K). This refers to the compression ratio; The adiabatic coefficient is taken as 1.4; The universal gas constant is taken as 8.314; By solving (generally )get .

7. The method for coordinated control of the glow plug and in-cylinder fuel injection quantity during the cold start process of a diesel engine according to claim 1, characterized in that, The change in oxygen content after the glow plug starts working is calculated using oxygen balance, including: in, For the combustion efficiency of the glow plug, The intake air mass flow rate is expressed in kg / s. This refers to the fuel injection rate for the glow plug, expressed in kg / s.

8. The method for coordinated control of the glow plug and in-cylinder fuel injection quantity during the cold start process of a diesel engine according to claim 1, characterized in that, The calculation and execution of the in-cylinder fuel injection quantity includes the following steps: 1) Estimate the intake mass flow rate of air for each cycle. ; 2) Obtain the target air-fuel ratio ; 3) Calculate the corrected air-fuel ratio: ; 4) Calculate the target equivalent ratio: ; 5) Calculate the in-cylinder fuel injection quantity: ; 6) Convert to injector pulse width signal to control the injector actuator to perform injection operation.

9. The method for coordinated control of the glow plug and in-cylinder fuel injection quantity during the cold start process of a diesel engine according to any one of claims 1-7, characterized in that, When implementing the control method, the basic values ​​for the entire operating condition range are generated offline based on the MATLAB physical model. The data is then stored in the memory (ROM) of the electronic control unit (ECU) in the form of a two-dimensional or three-dimensional table. When the system is under actual control, the accurate value of the current operating condition is obtained through bilinear interpolation.

Images