A detection and control system for automobile engine idling speed

Abstract

This invention relates to the field of idling speed control, and more particularly to a detection and control system for automotive engine idling speed. The invention comprises a power unit, a detection device, and a central control processor. The central control processor generates an idling speed variation curve based on the engine speed value, determines the vehicle's idling state based on the curve, and adjusts the valve opening of the intake unit in real time based on the air flow rate in the first idling state. In the second idling state, it calculates intake characteristic parameters based on intake parameters, adjusts the valve opening of the intake unit based on these parameters, and determines whether to adjust the fuel injector's injection flow rate based on the change in oxygen concentration after adjusting the valve opening. This invention can automatically and adaptively adjust the valve opening of the intake unit or the injection flow rate of the fuel injector, improving the control of engine-related operating parameters when the engine idling speed is abnormal, and enhancing the reliability and efficiency of suppressing abnormal engine idling speed.

Description

Technical Field

[0001] This invention relates to the field of idling speed control, and more particularly to a detection and control system for the idling speed of an automobile engine. Background Technology

[0002] Automotive engine idling speed refers to the state in which the engine speed remains within a certain range when the vehicle is stopped or moving at a slow speed. The detection and control of automotive engine idling speed is of great significance to ensure normal engine operation, reduce emissions, improve fuel economy, and enhance driving comfort.

[0003] Chinese Patent Publication No. CN112343722A discloses the following: This invention provides a method for controlling automotive idling speed, belonging to the field of automotive technology. It solves the problem that existing idling speed control methods still require frequent accelerator pedal input during creeping, resulting in insufficient driving comfort. The automotive idling speed control method includes the following steps: The TCU determines whether the conditions for entering idling speed control are met based on the vehicle's current gear, brake signal, and accelerator opening. When the conditions are met, the TCU enters idle speed request control, calculates the vehicle's current gradient value based on the longitudinal acceleration signal and vehicle speed signal, obtains the corresponding engine target idle speed value based on the calculated gradient value and current vehicle speed, and outputs an idle speed request signal to the ECU. The ECU responds to the idle speed request signal and adjusts the engine idle speed to the engine target idle speed value. When the conditions for entering idle speed control are not met, the TCU exits idle speed request control, and the ECU controls the engine idle speed value to return to the initial idle speed value. This automotive idling speed control method can improve driving comfort.

[0004] However, the following problems still exist in the existing technology:

[0005] In the existing technology, there is no consideration to adaptively adjust and correct the various operating units of the car engine according to the different changes in engine speed when the car engine is idling, so as to improve the idling speed control effect of the engine. Summary of the Invention

[0006] To solve the above problems, the present invention provides a detection and control system for automobile engine idling speed, comprising:

[0007] A power unit includes a cylinder block, an intake unit disposed at the top of the cylinder block for introducing air into the cylinder block, an exhaust unit disposed at the bottom of the cylinder block for discharging exhaust gases after combustion, and a rotating unit disposed inside the cylinder block for outputting power.

[0008] The detection device includes an oxygen concentration acquisition unit disposed on the exhaust unit for detecting the oxygen concentration value in the exhaust gas discharged from the cylinder block, a rotation speed acquisition unit disposed on the rotating unit for detecting the rotation speed value of the rotating unit, and a gas pressure acquisition unit, an air temperature acquisition unit, and a gas flow acquisition unit disposed on the intake unit for detecting the air pressure value, the air temperature value, and the air flow rate value, respectively.

[0009] The central control processor includes an analysis unit, a first control unit, and a second control unit that are interconnected.

[0010] The analysis unit is connected to the detection device to generate an idle speed change curve based on the rotational speed value, and to determine the vehicle's idle speed state based on the idle speed change curve. The idle speed state includes a first idle speed state and a second idle speed state.

[0011] The first control unit is connected to the power unit and the detection device, and is used to adjust the valve opening of the intake unit in real time based on the air flow value when the analysis unit determines that the idling state of the vehicle is the first idling state, until the air flow value is within a preset reasonable flow range.

[0012] The second control unit is connected to the power unit and the detection device, and is used to calculate the intake characteristic parameters based on the intake parameters when the analysis unit determines that the idling state of the vehicle is the second idling state, adjust the valve opening of the intake unit based on the intake characteristic parameters, and determine whether the injection flow of the fuel injector needs to be adjusted based on the change in the oxygen concentration value after adjusting the valve opening. The intake parameters include air pressure value, air temperature value and air flow value.

[0013] Furthermore, the analysis unit generates an idle speed variation curve based on the rotational speed value, wherein,

[0014] The analysis unit constructs a rectangular coordinate system with time as the X-axis and the rotational speed as the Y-axis, and constructs the idle speed change curve in the rectangular coordinate system.

[0015] Furthermore, the analysis unit determines the fluctuation parameters of the idle speed variation curve, wherein,

[0016] The analysis unit constructs several straight lines parallel to the Y-axis and with equal spacing in the rectangular coordinate system to divide the idle speed change curve into several idle speed change curve segments, determines the slope K of the midpoint of each idle speed change curve segment, and calculates the fluctuation parameter ΔK of the idle speed change curve according to formula (1).

[0017] (1)

[0018] In formula (1), K i+1 K represents the slope of the midpoint of the (i+1)th idle speed change curve segment. i The slope of the midpoint of the i-th idle speed change curve segment is represented by , n represents the number of idle speed change curve segments, and i represents an integer greater than 0.

[0019] Furthermore, the analysis unit determines the vehicle's idling state based on the idling speed change curve, wherein,

[0020] The analysis unit compares the fluctuation parameter with a preset slope comparison interval, where the midpoint of the slope comparison interval is 0.

[0021] Under the first slope comparison condition, the analysis unit determines the vehicle's idling state as the first idling state;

[0022] Under the second slope comparison condition, the analysis unit determines that the vehicle's idling state is the second idling state;

[0023] The first slope comparison condition is that the fluctuation parameter is within the preset slope comparison interval and the absolute value of the fluctuation parameter is greater than the preset stability index threshold. The second slope comparison condition is that the fluctuation parameter is not within the preset slope comparison interval. The stability index threshold is determined based on the upper limit of the slope comparison interval.

[0024] Furthermore, the first control unit adjusts the valve opening of the intake unit in real time based on the airflow value until the airflow value is within a preset reasonable flow range, wherein...

[0025] The first control unit compares the airflow value with a preset reasonable flow range in real time.

[0026] Under the first flow rate comparison condition, the first control unit reduces the valve opening of the intake unit;

[0027] Under the second flow comparison condition, the first control unit increases the valve opening of the intake unit;

[0028] Wherein, the first flow comparison condition is that the air flow value is greater than the upper limit of the reasonable flow range, and the second flow comparison condition is that the air flow value is less than the lower limit of the reasonable flow range.

[0029] Furthermore, the second control unit calculates intake characteristic parameters based on the intake parameters, wherein,

[0030] The second control unit determines the intake parameters and calculates the intake characteristic parameter E according to formula (2).

[0031] (2)

[0032] In formula (2), P represents the air pressure value, T represents the air temperature value, Q represents the air flow rate value, P0 represents the preset pressure comparison parameter, T0 represents the preset temperature comparison parameter, and Q0 represents the preset flow rate comparison parameter.

[0033] Furthermore, the second control unit adjusts the valve opening of the intake unit based on the intake characteristic parameters, wherein,

[0034] Under a first preset condition, the valve opening is reduced, and the reduction amount is positively correlated with the intake characteristic parameter.

[0035] Under the second preset condition, increasing the valve opening increases the amount of increase, which is negatively correlated with the intake characteristic parameter.

[0036] The first preset condition is that the fluctuation parameter of the idle speed change curve is positive, and the second preset condition is that the fluctuation parameter of the idle speed change curve is negative.

[0037] Furthermore, the second control unit determines whether the fuel injector injection flow rate needs to be adjusted based on the change in oxygen concentration after adjusting the valve opening.

[0038] The oxygen concentration value is compared with a preset oxygen concentration comparison range;

[0039] If the oxygen concentration value does not fall within the oxygen concentration comparison range, it is determined that the injection flow rate of the fuel injector needs to be adjusted, including increasing or decreasing the injection flow rate of the fuel injector.

[0040] Furthermore, when the second control unit determines that the injection flow rate of the fuel injector is being adjusted, it controls the valve opening to return to the initial opening.

[0041] Furthermore, the intake unit includes an intake pipe, a valve disposed within the intake pipe, and a fuel injector. The valve has an adjustable opening, and the fuel injector has an adjustable injection flow rate.

[0042] Compared with existing technologies, this invention, by setting up a power unit, a detection device, and a central control processor, generates an idle speed change curve based on the engine speed value, determines the vehicle's idle speed state based on the idle speed change curve, and adjusts the valve opening of the intake unit in real time based on the air flow value in the first idle speed state. In the second idle speed state, it calculates the intake characteristic parameters based on the intake parameters, adjusts the valve opening of the intake unit based on the intake characteristic parameters, and determines whether the injection flow of the fuel injector needs to be adjusted based on the change in the oxygen concentration value after adjusting the valve opening. This invention can automatically and adaptively adjust the valve opening of the intake unit or the injection flow of the fuel injector, improving the control of engine-related operating parameters when the engine idles abnormally, and improving the reliability and efficiency of suppressing engine idle abnormalities.

[0043] In particular, in this invention, the analysis unit generates an idle speed variation curve based on the engine speed value and determines the vehicle's idle speed state based on the idle speed variation curve. The idle speed variation curve is a curve formed by the change of the engine speed value over time. In actual situations, the idle speed of a vehicle engine is within the normal range but there are unstable situations with fluctuations. Often, the fluctuation parameter of the idle speed variation curve is within a stable range. Under abnormal conditions, the speed fluctuation will have large fluctuations within a certain period. Under different fluctuation conditions, the main factors affecting the idle speed also differ to some extent. This invention characterizes the speed fluctuation by calculating the fluctuation parameter of the idle speed variation curve, which facilitates subsequent automatic adjustment of the intake unit valve opening or the injection flow of the fuel injector according to different situations. This improves the control of engine-related operating parameters when the engine idle speed is abnormal, and improves the reliability and efficiency of suppressing engine idle speed abnormalities.

[0044] In particular, in this invention, the first control unit adjusts the valve opening of the intake unit in real time based on the air flow value during the first idle state until the air flow value is within a preset reasonable flow range. In actual situations, when the idle speed of the car engine fluctuates but the fluctuation is small during the first idle state, the valve opening of the intake unit can be adjusted appropriately based solely on the air flow to reduce vibration and improve ride comfort.

[0045] In particular, in this invention, the second control unit calculates intake characteristic parameters based on intake parameters during the second idle state, adjusts the valve opening of the intake unit based on the intake characteristic parameters, and determines whether the injection flow of the fuel injector needs to be adjusted based on the change in the oxygen concentration value after adjusting the valve opening. The main factor affecting the idling stability of a car engine is the air flow entering the engine block, although other factors include air flow, air pressure, and air temperature. When these parameters are abnormal, the engine will experience a "suffocation" phenomenon because the engine control system needs to maintain an appropriate air-fuel ratio (the ratio of air to fuel). Abnormal intake characteristic parameters will lead to a higher air-fuel ratio, resulting in unstable combustion in the engine and subsequent speed fluctuations, causing the aforementioned abnormalities. The main issues are abnormal valves and abnormal fuel injection. Firstly, based on intake characteristic parameters, the adjustment amount of the intake unit's valve opening is adaptively determined. Then, an oxygen concentration comparison range is determined based on the adjustment amount. If the change in oxygen concentration after adjusting the valve does not meet the preset standard, it indicates that the fuel injection is insufficient or excessive. If the fuel injection is insufficient, the change in oxygen concentration after adjusting the valve opening will be larger than the oxygen concentration comparison range. If the fuel injection is excessive, combustion will be more complete after adjusting the valve opening, and the change in oxygen concentration will be smaller than the oxygen concentration comparison range. Correspondingly, the intake unit's valve opening or the fuel injector's injection flow rate can be adaptively adjusted, improving the control of relevant engine operating parameters when the engine idles abnormally, and enhancing the reliability and efficiency of suppressing abnormal engine idling. Attached Figure Description

[0046] Figure 1 A schematic diagram of the structure of the automobile engine idling speed detection and control system according to an embodiment of the invention;

[0047] Figure 2 This is a simplified structural diagram of the central control processor in an embodiment of the invention. Detailed Implementation

[0048] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0049] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0050] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0051] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0052] Please see Figure 1 as well as Figure 2 As shown, this is a schematic diagram of the automotive engine idling speed detection and control system and a simplified diagram of the central control processor structure according to an embodiment of the present invention. The automotive engine idling speed detection and control system of the present invention includes:

[0053] A power unit includes a cylinder block, an intake unit disposed at the top of the cylinder block for introducing air into the cylinder block, an exhaust unit disposed at the bottom of the cylinder block for discharging exhaust gases after combustion, and a rotating unit disposed inside the cylinder block for outputting power.

[0054] The detection device includes an oxygen concentration acquisition unit disposed on the exhaust unit for detecting the oxygen concentration value in the exhaust gas discharged from the cylinder block, a rotation speed acquisition unit disposed on the rotating unit for detecting the rotation speed value of the rotating unit, and a gas pressure acquisition unit, an air temperature acquisition unit, and a gas flow acquisition unit disposed on the intake unit for detecting the air pressure value, the air temperature value, and the air flow rate value, respectively.

[0055] The central control processor includes an analysis unit, a first control unit, and a second control unit that are interconnected.

[0056] The analysis unit is connected to the detection device to generate an idle speed change curve based on the rotational speed value, and to determine the vehicle's idle speed state based on the idle speed change curve. The idle speed state includes a first idle speed state and a second idle speed state.

[0057] The first control unit is connected to the power unit and the detection device, and is used to adjust the valve opening of the intake unit in real time based on the air flow value when the analysis unit determines that the idling state of the vehicle is the first idling state, until the air flow value is within a preset reasonable flow range.

[0058] The second control unit is connected to the power unit and the detection device, and is used to calculate the intake characteristic parameters based on the intake parameters when the analysis unit determines that the idling state of the vehicle is the second idling state, adjust the valve opening of the intake unit based on the intake characteristic parameters, and determine whether the injection flow of the fuel injector needs to be adjusted based on the change in the oxygen concentration value after adjusting the valve opening. The intake parameters include air pressure value, air temperature value and air flow value.

[0059] Specifically, the power unit also includes a cooling unit located outside the cylinder block and connected to the cylinder block via pipes for dissipating heat from inside the cylinder block.

[0060] Specifically, the present invention does not limit the specific structure of the cylinder block. It can be a sealed structure made of cast iron or aluminum alloy. It only needs to be able to accommodate components such as pistons, valves, and crankshafts, form the combustion chamber of the engine, and ultimately convert chemical energy into mechanical energy to drive the car forward. Further details are not required.

[0061] Specifically, the present invention does not limit the specific structure of the exhaust unit, as long as it can perform the function of expelling the exhaust gas generated after combustion from the engine. This is existing technology and will not be described in detail.

[0062] Specifically, the present invention does not limit the specific structure of the detection device. It can be a combination of a sensor and a data transmission module. The data transmission module transmits the data detected by the sensor to the central control processor. It only needs to be able to complete the function of detecting the corresponding data and sending it to the central control processor. This is the prior art and will not be described in detail here.

[0063] Specifically, the present invention does not limit the specific form of the central control processor. It can be an external computer, in which each unit is a different functional program in the computer. It only needs to be able to complete the functions of data processing and data exchange. This is a mature existing technology and will not be described in detail.

[0064] Specifically, this invention does not limit the specific connection method between each unit in the central control processor and the power unit and the detection device. It only needs to complete the communication connection between each unit and each acquisition unit set in the detection device and the control system of the power unit, so as to realize the function of acquiring the data detected by each acquisition unit and controlling the valve opening of the intake unit. This is an existing mature technology and will not be described in detail.

[0065] Specifically, the analysis unit generates an idle speed variation curve based on the rotational speed value, wherein,

[0066] The analysis unit constructs a rectangular coordinate system with time as the X-axis and the rotational speed as the Y-axis, and constructs the idle speed change curve in the rectangular coordinate system.

[0067] Specifically, the analysis unit determines the fluctuation parameters of the idle speed variation curve, wherein,

[0068] The analysis unit constructs several straight lines parallel to the Y-axis and with equal spacing in the rectangular coordinate system to divide the idle speed change curve into several idle speed change curve segments, determines the slope K of the midpoint of each idle speed change curve segment, and calculates the fluctuation parameter ΔK of the idle speed change curve according to formula (1).

[0069] (1)

[0070] In formula (1), K i+1 K represents the slope of the midpoint of the (i+1)th idle speed change curve segment. i The slope of the midpoint of the i-th idle speed change curve segment is represented by , n represents the number of idle speed change curve segments, and i represents an integer greater than 0.

[0071] Specifically, the analysis unit determines the vehicle's idling state based on the idling speed change curve, wherein,

[0072] The analysis unit determines the vehicle's idling state based on the idling speed change curve, wherein...

[0073] The analysis unit compares the fluctuation parameter with a preset slope comparison interval, where the midpoint of the slope comparison interval is 0.

[0074] Under the first slope comparison condition, the analysis unit determines the vehicle's idling state as the first idling state;

[0075] Under the second slope comparison condition, the analysis unit determines that the vehicle's idling state is the second idling state;

[0076] The first slope comparison condition is that the fluctuation parameter is within the preset slope comparison interval and the absolute value of the fluctuation parameter is greater than the preset stability index threshold. The second slope comparison condition is that the fluctuation parameter is not within the preset slope comparison interval. The stability index threshold is determined based on the upper limit of the slope comparison interval, and the stability index threshold is set to 0.2 times the upper limit of the interval.

[0077] Specifically, in this embodiment, the upper and lower limits of the preset slope comparison interval are determined based on the fluctuation parameter △K of the idle speed change curve measured by the engine under experimental conditions for a certain period of time. The lower limit of the interval is set to △K1=-1.2|△K0|, and the upper limit of the interval is set to △K2=1.2|△K0|.

[0078] Specifically, in this invention, the analysis unit generates an idle speed variation curve based on the engine speed value and determines the vehicle's idle speed state based on the idle speed variation curve. The idle speed variation curve is a curve formed by the change of the engine speed value over time. In actual situations, the idle speed of a vehicle engine is within the normal range but exhibits unstable fluctuations. Often, the fluctuation parameter of the idle speed variation curve is within a stable range. Under abnormal conditions, the speed fluctuation will have large fluctuations within a certain period. Under different fluctuation conditions, the main factors affecting the idle speed also differ to some extent. This invention characterizes the speed fluctuation by calculating the fluctuation parameter of the idle speed variation curve, which facilitates subsequent automatic adjustment of the intake unit valve opening or the injection flow of the fuel injector according to different conditions. This improves the control of engine-related operating parameters when the engine idle speed is abnormal, and enhances the reliability and efficiency of suppressing abnormal engine idle speed.

[0079] Specifically, the first control unit adjusts the valve opening of the intake unit in real time based on the airflow value until the airflow value is within a preset reasonable flow range, wherein...

[0080] The first control unit compares the airflow value Q with a preset reasonable flow range [Q1, Q2] in real time, where 0 < Q1 < Q2.

[0081] Under the first flow rate comparison condition, the first control unit reduces the valve opening of the intake unit;

[0082] Under the second flow comparison condition, the first control unit increases the valve opening of the intake unit;

[0083] The first traffic comparison condition is Q > Q2, and the second traffic comparison condition is Q < Q1.

[0084] Specifically, the lower limit Q1 and the upper limit Q2 of the reasonable flow range are determined based on the average air flow value Q0 of the engine under stable operation in the experimental environment, with Q1=0.8Q0 and Q2=1.2Q0.

[0085] In this invention, the first control unit adjusts the valve opening of the intake unit in real time based on the air flow value during the first idle state until the air flow value is within a preset reasonable flow range. In actual situations, when the car engine idle speed fluctuates but the fluctuation is small during the first idle state, the valve opening of the intake unit can be adjusted appropriately based solely on the air flow to reduce vibration and improve ride comfort.

[0086] Specifically, in this invention, the first control unit adjusts the valve opening of the intake unit in real time based on the air flow value during the first idle state until the air flow value is within a preset reasonable flow range. In actual situations, during the first idle state where the car engine idle speed is within the normal range but fluctuates, the main factor affecting the stability of the car engine idle speed is the air flow entering the cylinder block. If the air flow entering the cylinder block is insufficient, the engine will experience a "suffocation" phenomenon, resulting in incomplete combustion, leading to unstable idle speed or even stalling. In this case, the valve opening should be increased to increase the air flow. If the air flow is too excessive, the engine will experience a "flooding" phenomenon, resulting in excessive combustion, which will also lead to unstable idle speed. In this case, the valve opening should be decreased to reduce the air flow. Therefore, during the first idle state, the valve opening of the intake unit can be reliably adjusted based on the air flow value, improving the efficiency and effectiveness of adjusting the car engine idle speed.

[0087] Specifically, the second control unit calculates intake characteristic parameters based on intake parameters, wherein,

[0088] The second control unit determines the intake parameters and calculates the intake characteristic parameter E according to formula (2).

[0089] (2)

[0090] In formula (2), P represents the air pressure value, T represents the air temperature value, Q represents the air flow rate value, P0 represents the preset pressure comparison parameter, P0>0, T0 represents the preset temperature comparison parameter, T0>0, and Q0 represents the preset flow rate comparison parameter, Q0>0.

[0091] Specifically, in this embodiment, P0, T0, and Q0 are the average values ​​of air pressure, air temperature, and air flow rate measured when the engine is operating stably under experimental conditions, respectively.

[0092] Specifically, the second control unit adjusts the valve opening of the intake unit based on the intake characteristic parameters, wherein,

[0093] Under a first preset condition, the valve opening is reduced, and the reduction amount is positively correlated with the intake characteristic parameter.

[0094] Under the second preset condition, increasing the valve opening increases the amount of increase, which is negatively correlated with the intake characteristic parameter.

[0095] The first preset condition is that the fluctuation parameter of the idle speed change curve is positive, and the second preset condition is that the fluctuation parameter of the idle speed change curve is negative.

[0096] Specifically, the second control unit reduces the valve opening, and the reduction amount is positively correlated with the intake characteristic parameter, wherein...

[0097] The second control unit compares the intake characteristic parameter E with preset first parameter comparison threshold E1 and second parameter comparison threshold E2, where 0 < E1 < E2.

[0098] Based on the first parameter comparison result, the second control unit determines that the reduction in the valve opening of the intake unit is the preset first valve opening reduction parameter. 11 ;

[0099] Based on the second parameter comparison result, the second control unit determines that the reduction in the valve opening of the intake unit is the preset second valve opening reduction parameter. 12 ;

[0100] Based on the comparison result of the third parameter, the second control unit determines that the reduction in the valve opening of the intake unit is the preset third valve opening reduction parameter. 13 ;

[0101] Wherein, the first parameter comparison result is E≥E2, the second parameter comparison result is E1≤E<E2, and the third parameter comparison result is E<E1, 10%>o. 11 >o 12 >o 13 .

[0102] Specifically, the second control unit increases the valve opening, and the increase is negatively correlated with the intake characteristic parameter.

[0103] The third control unit compares the intake characteristic parameter E with preset third parameter comparison threshold E3 and fourth parameter comparison threshold E4, where 0 < E3 < E4 < E1.

[0104] Based on the fourth parameter comparison result, the second control unit determines that the increase in the valve opening of the intake unit is a preset first valve opening increase parameter. 21 ;

[0105] Based on the comparison result of the fifth parameter, the second control unit determines that the decrease in the valve opening of the intake unit is equal to the preset second valve opening increase parameter. 22;

[0106] Based on the comparison result of the sixth parameter, the second control unit determines that the decrease in the valve opening of the intake unit is equal to the preset third valve opening increase parameter. 23 ;

[0107] Among them, the comparison result of the fourth parameter is E≥E4, the comparison result of the fifth parameter is E3≤E<E4, and the comparison result of the sixth parameter is E<E3. 21 <o 22 <o 23 <10%.

[0108] Specifically, the first parameter comparison threshold E1, the second parameter comparison threshold E2, the third parameter comparison threshold E3, and the fourth parameter comparison threshold E4 are calculated based on the average value E0 of the intake characteristic parameters over a certain period of time under stable operating conditions of the engine in the experiment. E1=1.2E0, E2=1.4E0, E3=0.6E0, and E4=0.8E0.

[0109] Specifically, those skilled in the art can set o11~o13 and o21~o23 within a limited range. When setting these ranges, the difference ratio F needs to be controlled within 0.3 to ensure differentiation while avoiding excessive differences. F is set as follows: 1，i+1 -o 1，i ) / o 1，i F = (o 2，i+1 -o 2，i ) / o 2，i , where o 1，i This indicates the parameter for decreasing the opening of the i-th valve, o 1，i+1 This indicates the parameter for decreasing the valve opening at the (i+1)th valve, o 2，i This indicates the parameter for increasing the opening of the i-th valve, o 2，i+1 This represents the parameter for increasing the opening of the (i+1)th valve.

[0110] In this invention, the second control unit calculates intake characteristic parameters based on intake parameters during the second idle state. Based on these intake characteristic parameters, it adjusts the valve opening of the intake unit and determines whether to adjust the fuel injector's injection flow rate based on the change in oxygen concentration after adjusting the valve opening. The main factor affecting the stable idle speed of a car engine is the airflow entering the engine block, although other factors include airflow, air pressure, and air temperature. When these parameters are abnormal, the engine will experience a "suffocation" phenomenon because the engine control system needs to maintain an appropriate air-fuel ratio (the ratio of air to fuel). Abnormal intake characteristic parameters will lead to a higher air-fuel ratio, resulting in unstable combustion in the engine and subsequent speed fluctuations, causing the aforementioned abnormal situation. The main issues are abnormal valves and abnormal fuel injection. Firstly, based on intake characteristic parameters, the adjustment amount of the intake unit's valve opening is adaptively determined. Then, an oxygen concentration comparison range is determined based on this adjustment. If the change in oxygen concentration after valve adjustment does not meet the preset standard, it indicates insufficient or excessive fuel injection. If the fuel injection is insufficient, the change in oxygen concentration after adjusting the valve opening will be larger than the oxygen concentration comparison range. If the fuel injection is excessive, combustion will be more complete after adjusting the valve opening, and the change in oxygen concentration will be smaller than the oxygen concentration comparison range. Correspondingly, the intake unit's valve opening or the fuel injector's injection flow rate can be adaptively adjusted, improving the control of relevant engine operating parameters when the engine idles abnormally, and enhancing the reliability and efficiency of suppressing abnormal engine idling.

[0111] Specifically, the second control unit determines whether the fuel injector's injection flow rate needs adjustment based on the change in oxygen concentration after adjusting the valve opening.

[0112] The oxygen concentration value is compared with a preset oxygen concentration comparison range;

[0113] If the oxygen concentration value does not fall within the oxygen concentration comparison range, it is determined that the injection flow rate of the fuel injector needs to be adjusted, including increasing or decreasing the injection flow rate of the fuel injector.

[0114] When increasing or decreasing the injection flow rate of a fuel injector, the amount of increase or decrease can be determined by those skilled in the art according to specific needs, and will not be elaborated here.

[0115] In this embodiment, the oxygen concentration comparison range is determined based on the valve opening adjustment amount. The central control processor stores the oxygen concentration comparison range corresponding to different valve opening adjustment amounts under normal engine operation. The above data is measured under experimental conditions and stored in the central control processor.

[0116] Specifically, when the second control unit determines that the injection flow rate of the fuel injector is to be adjusted, it controls the valve opening to return to the initial opening.

[0117] Specifically, the intake unit includes an intake pipe, a valve disposed in the intake pipe, and a fuel injector. The valve can adjust the opening degree, and the fuel injector can adjust the injection flow rate.

[0118] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A detection and control system for automobile engine idling speed, characterized in that, include: A power unit includes a cylinder block, an intake unit disposed at the top of the cylinder block for introducing air into the cylinder block, an exhaust unit disposed at the bottom of the cylinder block for discharging exhaust gases after combustion, and a rotating unit disposed inside the cylinder block for outputting power. The detection device includes an oxygen concentration acquisition unit disposed on the exhaust unit for detecting the oxygen concentration value in the exhaust gas discharged from the cylinder block, a rotation speed acquisition unit disposed on the rotating unit for detecting the rotation speed value of the rotating unit, and a gas pressure acquisition unit, an air temperature acquisition unit, and a gas flow acquisition unit disposed on the intake unit for detecting the air pressure value, the air temperature value, and the air flow rate value, respectively. The central control processor includes an analysis unit, a first control unit, and a second control unit that are interconnected. The analysis unit is connected to the detection device to generate an idle speed change curve based on the rotational speed value, and to determine the vehicle's idle speed state based on the idle speed change curve. The idle speed state includes a first idle speed state and a second idle speed state. The first control unit is connected to the power unit and the detection device, and is used to adjust the valve opening of the intake unit in real time based on the air flow value when the analysis unit determines that the idling state of the vehicle is the first idling state, until the air flow value is within a preset reasonable flow range. The second control unit is connected to the power unit and the detection device, and is used to calculate the intake characteristic parameters based on the intake parameters when the analysis unit determines that the idling state of the vehicle is the second idling state, adjust the valve opening of the intake unit based on the intake characteristic parameters, and determine whether the injection flow of the fuel injector needs to be adjusted based on the change of the oxygen concentration value after adjusting the valve opening. The intake parameters include air pressure value, air temperature value and air flow value. The analysis unit generates an idle speed change curve based on the rotational speed value. The analysis unit constructs a rectangular coordinate system with time as the X-axis and the rotational speed value as the Y-axis, and constructs the idle speed change curve in the rectangular coordinate system. The analysis unit determines the fluctuation parameters of the idle speed variation curve, wherein, The analysis unit constructs several straight lines parallel to the Y-axis and with equal spacing in the rectangular coordinate system to divide the idle speed change curve into several idle speed change curve segments, determines the slope K of the midpoint of each idle speed change curve segment, and calculates the fluctuation parameter ΔK of the idle speed change curve according to formula (1). (1) In formula (1), K i+1 K represents the slope of the midpoint of the (i+1)th idle speed change curve segment. i The slope of the midpoint of the i-th idle speed change curve segment is represented by n, where n represents the number of idle speed change curve segments and i represents an integer greater than 0. The analysis unit determines the vehicle's idling state based on the idling speed change curve. The analysis unit compares the fluctuation parameter with a preset slope comparison interval, where the midpoint of the slope comparison interval is 0. Under a first slope comparison condition, the analysis unit determines the vehicle's idling state as a first idling state; under a second slope comparison condition, the analysis unit determines the vehicle's idling state as a second idling state. The first slope comparison condition is that the fluctuation parameter is within the preset slope comparison interval, and the absolute value of the fluctuation parameter is greater than a preset stability index threshold. The second slope comparison condition is that the fluctuation parameter is not within the preset slope comparison interval. The stability index threshold is determined based on the upper limit of the slope comparison interval. The second control unit calculates the intake characteristic parameters based on the intake parameters, wherein the second control unit determines the intake parameters and calculates the intake characteristic parameter E according to formula (2). （2） In formula (2), P represents the air pressure value, T represents the air temperature value, Q represents the air flow rate value, P0 represents the preset pressure comparison parameter, T0 represents the preset temperature comparison parameter, and Q0 represents the preset flow rate comparison parameter. The second control unit adjusts the valve opening of the intake unit based on the intake characteristic parameters. Under a first preset condition, the valve opening is reduced, and the reduction amount is positively correlated with the intake characteristic parameters. Under a second preset condition, the valve opening is increased, and the increase amount is negatively correlated with the intake characteristic parameters. The first preset condition is that the fluctuation parameter of the idle speed change curve is positive, and the second preset condition is that the fluctuation parameter of the idle speed change curve is negative.

2. The detection and control system for automobile engine idling speed according to claim 1, characterized in that, The first control unit adjusts the valve opening of the intake unit in real time based on the airflow value until the airflow value is within a preset reasonable flow range, wherein... The first control unit compares the airflow value with a preset reasonable flow range in real time. Under the first flow rate comparison condition, the first control unit reduces the valve opening of the intake unit; Under the second flow comparison condition, the first control unit increases the valve opening of the intake unit; Wherein, the first flow comparison condition is that the air flow value is greater than the upper limit of the reasonable flow range, and the second flow comparison condition is that the air flow value is less than the lower limit of the reasonable flow range.

3. The detection and control system for automobile engine idling speed according to claim 1, characterized in that, The second control unit determines whether the fuel injector injection flow rate needs to be adjusted based on the change in oxygen concentration after adjusting the valve opening. The oxygen concentration value is compared with a preset oxygen concentration comparison range; If the oxygen concentration value does not fall within the oxygen concentration comparison range, it is determined that the injection flow rate of the fuel injector needs to be adjusted, including increasing or decreasing the injection flow rate of the fuel injector.

4. The detection and control system for automobile engine idling speed according to claim 3, characterized in that, When the second control unit determines that the injection flow rate of the fuel injector is to be adjusted, it controls the valve opening to return to the initial opening.

5. The detection and control system for automobile engine idling speed according to claim 1, characterized in that, The intake unit includes an intake pipe, a valve disposed in the intake pipe, and a fuel injector. The valve can adjust the opening degree, and the fuel injector can adjust the injection flow rate.

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