Clutch control method, system and electronic device of a hybrid power system

Abstract

The application discloses a clutch control method and system of a hybrid power system and electronic equipment, and belongs to the technical field of hybrid power vehicle control. The method comprises the following steps: obtaining the Nernst voltage value of a front oxygen sensor output and performing filtering processing to obtain a filtered voltage value; determining the Nernst voltage change rate according to the filtered voltage value; when the filtered voltage value and the Nernst voltage change rate do not exceed the preset threshold value, determining engine misfire and outputting a misfire flag bit; calculating the impact stress borne by each shaft system based on the rotational inertia, angular velocity change and structural parameters of each shaft system; when the impact stress of all shaft systems does not exceed the corresponding maximum allowable stress, outputting a pressure building signal to control the clutch to maintain the engagement state; otherwise, outputting a pressure reducing signal to control the clutch to separate. The application can accurately identify the engine misfire condition, and actively cut off the power transmission path under the impact overload risk, thereby protecting the shaft system of the hybrid power system from damage.

Description

Technical Field

[0001] This invention relates to the field of hybrid vehicle control technology, specifically to a clutch control method, system, and electronic equipment for a hybrid power system. Background Technology

[0002] With global sales growth of pure electric vehicles falling short of expectations, major automakers are increasingly focusing on hybrid models to meet customer demand and facilitate the transition to electrification. Hybrid vehicles, by combining a traditional engine system with an electric drive system, can help reduce fuel consumption and emissions in the short term, while also offering significant advantages in terms of adapting to consumer driving habits and alleviating range anxiety.

[0003] However, hybrid systems inevitably have some problems. When the engine is running, misfires may occur due to various reasons such as ignition system malfunction, abnormal fuel supply, or insufficient air intake. Engine misfires cause a sharp change in output torque, which severely impacts the transmission system. The impact torque may far exceed the transmission system's limit torque, causing damage to the transmission system shafts and seriously affecting the vehicle's reliability and safety.

[0004] Several methods for monitoring engine misfires and clutch control schemes exist in the prior art. For example, Chinese patent CN115182813A provides a method for monitoring engine misfires in hybrid vehicles, which determines whether the engine is in a misfire condition by acquiring the actual misfire signal value corresponding to each preset time period window. However, this patent only involves misfire monitoring and does not provide a protection and control scheme for the transmission system after a misfire. Chinese patent CN119062752A provides a hydraulic control system and method for a transmission, which connects the clutch control circuit with the transmission cooling and lubrication circuit through a first pressure regulating valve to achieve adaptive control. However, this patent does not involve the determination of engine misfires, nor does it provide a specific clutch control method for when the engine misfires. Chinese patent CN119196300A provides a hydraulic control system and control method for a hybrid transmission, which controls an electric pump to supply oil to the clutch control subsystem through an oil replenishment subsystem to quickly adjust the clutch working state. However, it also lacks a method for determining engine misfires and a specific clutch control strategy for when the engine misfires.

[0005] Therefore, accurately identifying engine misfire conditions and effectively controlling clutch action when a misfire occurs to avoid impact overload on the hybrid power system shaft system are technical problems that still need to be solved. Summary of the Invention

[0006] To overcome the deficiencies in the prior art, this invention proposes a clutch control method, system, and electronic equipment for a hybrid power system, which can actively control clutch disengagement and interrupt torque transmission path after engine misfire, thereby avoiding shaft impact failure.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a clutch control method for a hybrid power system, comprising:

[0009] The Nernst voltage value output by the pre-oxygen sensor is obtained, and the Nernst voltage value is filtered to obtain the filtered voltage value.

[0010] The Nernst voltage change rate is determined based on the filtered voltage value, and when the filtered voltage value is less than or equal to a first threshold and the Nernst voltage change rate is less than or equal to a second threshold, it is determined that the engine has misfired and a misfire flag is output.

[0011] In response to the misfire flag, the impact stress on each shaft system is calculated based on the rotational inertia of each shaft system in the hybrid power system, the change in angular velocity of each shaft system before and after engine misfire, and the structural parameters of each shaft system.

[0012] The impact stress on each shaft system is compared with the maximum allowable stress of the corresponding shaft system, and the working state of the clutch is controlled according to the comparison results. When the impact stress on each shaft system is less than or equal to the corresponding maximum allowable stress, a pressure build-up signal is output to control the clutch to maintain the engagement state. When the impact stress on at least one shaft system is greater than the corresponding maximum allowable stress, a pressure reduction signal is output to control the clutch to disengage.

[0013] Optionally, the Nernst voltage value is obtained according to a preset sampling period, the filtered voltage value is obtained based on the real-time acquired Nernst voltage value, and the Nernst voltage change rate is obtained based on the filtered voltage value within adjacent sampling times or a preset time window.

[0014] Optionally, the calculation of the impact stress on each shaft system includes calculating the impact stress on each shaft system using the following formula: ;

[0015] In the formula: Let be the torsional section modulus of shaft system 1. Let be the moment of inertia of shaft system 1. This represents the change in angular velocity of shaft system 1 before and after the engine misfire. Let be the shear modulus of shaft system 1. Let be the polar moment of inertia of axis system 1. The bearing span of shaft system 1.

[0016] Optionally, the calculation of the impact stress on each shaft system further includes calculating the impact stress on shaft system n according to the following formula: ;

[0017] In the formula: Let n be the torsional section modulus of shaft system n. This represents the transmission ratio between shaft system 1 and shaft system n. Let be the outer diameter of the cross-section of shaft system 1. Let n be the outer diameter of the cross-section of shaft system n. The inner diameter ratio of shaft system 1, Let n be the ratio of the inner diameter of the shaft system n.

[0018] Optionally, the polar moment of inertia of the shaft system 1 is calculated according to the following formula:

[0019] ;

[0020] The torsional section modulus of shaft system 1 is calculated according to the following formula:

[0021]

[0022] In the formula: Let be the outer diameter of the cross-section of shaft system 1. The inner diameter ratio of shaft system 1 is the ratio of the inner diameter to the outer diameter of the shaft system.

[0023] Optionally, the polar moment of inertia of the axis system n is calculated according to the following formula: ;

[0024] The torsional section modulus of the shaft system n is calculated according to the following formula: ;

[0025] In the formula: Let n be the outer diameter of the cross-section of shaft system n. Let be the ratio of the inner diameter of shaft system n, which is the ratio of the inner diameter to the outer diameter of the shaft system.

[0026] Optionally, controlling the clutch to maintain engagement includes: controlling the target pressure of the clutch to be equal to the torque transmission pressure; controlling the clutch to disengage includes: controlling the target pressure of the clutch to decrease to less than the torque transmission pressure.

[0027] Optionally, controlling the working state of the clutch based on the comparison result includes: determining the target pressure of the clutch based on the comparison result, determining the pressure valve core displacement corresponding to the target pressure using a hydraulic chamber pressure-displacement curve, and adjusting the pressure valve core displacement based on the clutch pressure feedback signal so that the oil pressure in the piston chamber approaches the target pressure.

[0028] In a second aspect, the present invention provides a clutch control system for a hybrid power system, comprising:

[0029] The filtering module is used to obtain the Nernst voltage value output by the pre-oxygen sensor and to filter the Nernst voltage value to obtain the filtered voltage value.

[0030] The misfire condition identification module is used to determine the Nernst voltage change rate based on the filtered voltage value, and to determine that the engine has misfired and output a misfire flag bit when the filtered voltage value is less than or equal to a first threshold and the Nernst voltage change rate is less than or equal to a second threshold.

[0031] The system impact calculation module is used to calculate the impact stress on each shaft system in response to the misfire flag, based on the rotational inertia of each shaft system in the hybrid power system, the change in angular velocity of each shaft system before and after engine misfire, and the structural parameters of each shaft system.

[0032] The clutch control module is used to compare the impact stress on each shaft system with the maximum allowable stress of the corresponding shaft system, and control the working state of the clutch according to the comparison result. Specifically, when the impact stress on each shaft system is less than or equal to the corresponding maximum allowable stress, a pressure build-up signal is output to control the clutch to maintain the engagement state; when the impact stress on at least one shaft system is greater than the corresponding maximum allowable stress, a pressure reduction signal is output to control the clutch to disengage.

[0033] Thirdly, the present invention provides an electronic device, the electronic device comprising:

[0034] At least one processor; and a memory communicatively connected to said at least one processor; wherein,

[0035] The memory stores a computer program that can be executed by the at least one processor to enable the at least one processor to perform the method described in any one of the first aspects.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The present invention provides a clutch control method, system and electronic equipment for a hybrid power system. By using the Nernst voltage value and Nernst voltage change rate of the front oxygen sensor as dual indicators for determining engine misfire, it can effectively avoid the misjudgment problem caused by single threshold judgment and improve the accuracy and reliability of misfire condition identification.

[0038] In the process of system impact calculation, the calculation formula of impact stress of each shaft system is derived based on the law of conservation of energy. The formula fully considers the rotational inertia, angular velocity change and structural parameters (including shear modulus, polar moment of inertia, bearing span, torsional section modulus, cross-sectional outer diameter and inner diameter ratio, etc.) of each shaft system. It can accurately calculate the actual impact stress of each shaft system when the engine misfires, and provide a reliable decision basis for clutch control.

[0039] When a risk of impact failure is detected, the clutch is actively disengaged to interrupt the torque transmission path, which can effectively protect the shafts of the hybrid system from torsional impact damage and improve the reliability and safety of hybrid vehicles.

[0040] This invention employs a closed-loop pressure control method based on the hydraulic chamber pressure-displacement curve, which enables precise adjustment of clutch pressure and ensures the response speed and control accuracy of the clutch during engagement and disengagement. Attached Figure Description

[0041] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0042] Figure 1 This is a flowchart of a clutch control method for a hybrid power system provided by the present invention;

[0043] Figure 2 A schematic diagram illustrating the principle of the fire condition identification process provided in an embodiment of the present invention;

[0044] Figure 3 This is a block diagram of the clutch control system architecture of a hybrid power system provided in an embodiment of the present invention;

[0045] Figure 4 A schematic diagram illustrating the principle of the clutch control process provided in an embodiment of the present invention;

[0046] Figure 5 This is a schematic diagram of the pressure-displacement curve of the clutch hydraulic chamber provided in an embodiment of the present invention;

[0047] Figure 6 This is a schematic diagram of the hydraulic closed-loop control principle provided in an embodiment of the present invention;

[0048] Figure 7 This is a schematic diagram of a six-parallel-axis hybrid power system provided in an embodiment of the present invention.

[0049] Figure 8This is an internal structure diagram of the electronic device provided in an embodiment of the present invention. Detailed Implementation

[0050] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of the present invention and are therefore merely examples, and should not be construed as limiting the scope of protection of the present invention.

[0051] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0052] This invention provides a clutch control method, system, and electronic device for a hybrid power system. Embodiments of this invention are described below with reference to the accompanying drawings.

[0053] Example 1: As Figure 1 As shown, the clutch control method for a hybrid power system provided by the present invention includes the following steps:

[0054] Step S101: Obtain the Nernst voltage value output by the pre-oxygen sensor, and filter the Nernst voltage value to obtain the filtered voltage value;

[0055] Step S102: Determine the Nernst voltage change rate based on the filtered voltage value, and when the filtered voltage value is less than or equal to the first threshold and the Nernst voltage change rate is less than or equal to the second threshold, determine that the engine has misfired and output a misfire flag bit.

[0056] Step S103: In response to the misfire flag, calculate the impact stress on each shaft system based on the moment of inertia of each shaft system in the hybrid power system, the change in angular velocity of each shaft system before and after engine misfire, and the structural parameters of each shaft system.

[0057] Step S104: Compare the impact stress on each shaft system with the maximum allowable stress of the corresponding shaft system, and control the working state of the clutch according to the comparison result; wherein, when the impact stress on each shaft system is less than or equal to the corresponding maximum allowable stress, output a pressure build-up signal to control the clutch to maintain the engagement state; when the impact stress on at least one shaft system is greater than the corresponding maximum allowable stress, output a pressure reduction signal to control the clutch to disengage.

[0058] The specific implementation methods for each step are described in detail below with reference to the accompanying drawings.

[0059] In step S101, during the acquisition and filtering of the pre-oxygen sensor signal, the pre-oxygen sensor is an oxygen concentration sensor installed in the engine exhaust pipe. Its output Nernst voltage value reflects the engine combustion status. When the engine is operating normally, the Nernst voltage value of the pre-oxygen sensor fluctuates within a certain range; when the engine misfires, the oxygen concentration in the exhaust changes abruptly, and the Nernst voltage value changes accordingly. Since the sensor signal may be affected by measurement noise, the original Nernst voltage value needs to be filtered to extract an effective signal that truly reflects the combustion status. Filtering can employ low-pass filtering, mean filtering, or other conventional filtering methods.

[0060] like Figure 2 As shown, the fire condition identification process involves processing the Nernst voltage signal output by the front oxygen sensor.

[0061] The front oxygen sensor is installed in the engine exhaust pipe, and its output Nernst voltage value reflects the oxygen concentration in the exhaust. When the engine is working normally, the air-fuel mixture burns completely, the oxygen concentration in the exhaust is within the normal range, and the Nernst voltage value is also maintained within the corresponding normal range. When the engine misfires, unburned air-fuel mixture enters the exhaust pipe, causing a sudden change in the oxygen concentration in the exhaust, and the Nernst voltage value also changes significantly.

[0062] In this embodiment, the pre-oxygen sensor continuously outputs Nernst voltage values ​​according to a preset sampling period. The Nernst voltage values ​​are acquired according to the preset sampling period, and the filtered voltage value is obtained based on the real-time acquired Nernst voltage values.

[0063] Because sensor signals may be affected by electromagnetic interference, measurement noise, and other factors during acquisition and transmission, the raw Nernst voltage value needs to be filtered to eliminate noise interference and extract the effective signal. Filtering can be implemented in various ways, such as low-pass filtering—allowing low-frequency signals to pass while attenuating high-frequency noise; or mean filtering—taking the arithmetic average of multiple sampled values ​​within a preset time window. After filtering, the filtered voltage value u′ is obtained.

[0064] The Nernst voltage change rate Δu′ is obtained based on the filtered voltage value within adjacent sampling times or a preset time window. Specifically, the voltage change rate can be calculated as the difference between the filtered voltage value at the current sampling time and the filtered voltage value at the previous sampling time; alternatively, the voltage change rate can be calculated as the difference between the filtered voltage values ​​at the start and end times of a preset time window (e.g., 100 milliseconds) divided by the time window length.

[0065] When the filtered voltage value u′ is less than or equal to the first threshold u min And the rate of change of Nernst voltage Δu′ is less than or equal to the second threshold Δu. minWhen the engine misfires, a misfire flag is output.

[0066] The reason for using both voltage value and voltage change rate as two criteria is to improve the reliability of identification. Under certain operating conditions, the Nernst voltage value may temporarily decrease due to sensor drift, but the voltage change rate will not simultaneously become abnormal; conversely, the voltage change rate may briefly increase due to transient signal fluctuations, but the voltage value will not simultaneously drop below the threshold. A fire is only determined when both criteria are met simultaneously, effectively avoiding false alarms.

[0067] After a fire is detected, a fire alarm flag is output (e.g., a high-level signal or a specific identifier).

[0068] In step S102, the Nernst voltage change rate reflects the rate of change of the Nernst voltage value over time. This can be obtained by differentiating the filtered voltage value or by calculating the difference between adjacent sampling times. When the engine is operating normally, both the Nernst voltage value and its change rate remain within a relatively stable range. When an engine misfire occurs, the Nernst voltage value drops significantly, and the voltage change rate also shows corresponding abnormal changes. Therefore, the filtered voltage value is compared with a first threshold, and the Nernst voltage change rate is compared with a second threshold. When both exceed the normal range (i.e., the filtered voltage value is lower than or equal to the first threshold, and the Nernst voltage change rate is lower than or equal to the second threshold), an engine misfire can be determined. Using both voltage value and voltage change rate as dual determination indicators effectively avoids misjudgments that may occur with single-threshold judgments, improving the accuracy and reliability of misfire identification. After determining a misfire, a misfire flag is output.

[0069] In step S103, the system impact stress is calculated through the following specific implementation method:

[0070] In response to the misfire flag, the impact stress on each shaft system is calculated based on the rotational inertia of each shaft system in the hybrid power system, the change in angular velocity of each shaft system before and after engine misfire, and the structural parameters of each shaft system.

[0071] When the engine misfires, the output torque drops sharply, causing a sudden change in the rotational speed of the various transmission shafts connected to the engine crankshaft. Due to the inertia of the transmission system, this sudden change in speed will cause torsional impact loads on the shafts. The magnitude of this impact load depends on the moment of inertia of the shafts, the change in rotational speed, and the structural characteristics of the shafts themselves.

[0072] According to the law of conservation of energy, during an impact, the decrease in kinetic energy T and potential energy V of the impacting object should be equal to the increase in elastic deformation energy of the impacted object. ,Right now:

[0073]

[0074] After the engine misfires, the rotational speed of shaft 1 in the transmission system will suddenly decrease, and the amount of kinetic energy loss is:

[0075]

[0076] In the formula: Let be the moment of inertia of shaft system 1. The change in angular velocity of shaft system 1 before and after engine misfire;

[0077] Before and after the engine misfire, the potential energy of shaft 1 did not change significantly, that is, the change in potential energy V=0.

[0078] The increased torsional elastic deformation energy of shaft system 1 is:

[0079]

[0080] In the formula: The impact torque experienced by shaft system 1 This represents the angular displacement of axis 1.

[0081] During the torsion process of the shaft system, the angular displacement is:

[0082]

[0083] In the formula: The impact torque experienced by shaft system 1 Let be the angular displacement of axis system 1. Shearing mold for shaft system 1

[0084] quantity, Let be the polar inertia of axis 1.

[0085] Substituting equations (2), (3), and (4) into equation (1), we derive:

[0086]

[0087] The impact torque on shaft 1 is:

[0088]

[0089] In the formula: Let be the moment of inertia of shaft system 1. This represents the change in angular velocity of shaft system 1 before and after the engine misfire. Let be the shear modulus of shaft system 1. Let be the polar moment of inertia of axis system 1. The bearing span of shaft system 1;

[0090] Impact stress of shaft 1:

[0091]

[0092] In the formula: Let be the torsional section modulus of shaft system 1. Let be the moment of inertia of shaft system 1. This represents the change in angular velocity of shaft system 1 before and after the engine misfire. Let be the shear modulus of shaft system 1. Let be the polar moment of inertia of axis system 1. The bearing span of shaft system 1.

[0093] For hollow circular shafts (i.e., shaft systems with a central through hole), the polar moment of inertia and torsional section modulus are calculated according to the following formulas:

[0094]

[0095]

[0096] In the formula, Let be the outer diameter of the cross-section of the shaft system. The inner diameter ratio of the shaft system is the ratio of the inner diameter to the outer diameter of the shaft system.

[0097] For shaft system 1, substituting equations (8) and (9) into equation (7) yields:

[0098]

[0099] In the formula: Let be the outer diameter of the cross-section of shaft system 1. The inner diameter ratio of shaft system 1 is the ratio of the inner diameter to the outer diameter of the shaft system. This represents the change in rotational speed of shaft 1 before and after an engine misfire. Let be the shear modulus of shaft system 1. Let be the moment of inertia of shaft system 1. Let be the outer diameter of the cross-section of shaft system 1. The bearing span of shaft system 1. It is the inner diameter ratio of shaft system 1.

[0100] Similarly, the impact stress of shaft 2 is:

[0101]

[0102] In the formula: The section modulus of shaft system 2 is the torsional section modulus. This is the transmission ratio between shaft system 1 and shaft system 2. Let be the outer diameter of the cross-section of shaft system 1. The outer diameter of the cross-section of shaft system 2 is... The inner diameter ratio of shaft system 1, The inner diameter ratio of shaft system 2.

[0103] Following this logic, the impact stress of shaft system (n-1) is:

[0104]

[0105] In the formula: Let be the torsional section modulus of shaft system (n-1). Let be the transmission ratio between shaft system 1 and shaft system (n-1). Let be the outer diameter of the cross-section of shaft system 1. Let be the outer diameter of the cross-section of shaft system (n-1). The inner diameter ratio of shaft system 1, The inner diameter ratio of the shaft system (n-1);

[0106] The impact stress of shaft n is:

[0107]

[0108] In the formula: Let be the torsional section modulus of shaft system n, and be the transmission ratio between shaft system 1 and shaft system n. Let be the outer diameter of the cross-section of shaft system 1. Let n be the outer diameter of the cross-section of shaft system n. The inner diameter ratio of shaft system 1, Let n be the ratio of the inner diameter of the shaft system n.

[0109] Through the above calculations, the impact stress values ​​borne by each shaft system in the hybrid power system when the engine misfires can be obtained.

[0110] In step S104 above, the impact stress on each shaft system is compared with the maximum allowable stress of the corresponding shaft system, and the working state of the clutch is controlled according to the comparison result.

[0111] The maximum allowable stress [τ] is the maximum stress value that each shaft system is allowed to withstand in the design, which depends on the mechanical properties of the shaft system material and the design requirements. When the actual impact stress τ on the shaft system is less than or equal to its maximum allowable stress [τ], it indicates that the structural strength of the shaft system is sufficient to withstand the impact load, and there is no risk of impact failure. When the actual impact stress τ is greater than the maximum allowable stress [τ], it indicates that the shaft system has a risk of impact failure and protective measures need to be taken.

[0112] Specifically, when the impact stress on each shaft system is less than or equal to the corresponding maximum allowable stress, i.e., τ≤[τ] for each shaft system, there is no risk of impact failure. A pressure build-up signal is output to control the clutch to maintain engagement, ensuring normal torque transmission of the transmission system. Maintaining engagement specifically includes controlling the clutch's target pressure to equal the torque transmission pressure. Torque transmission pressure refers to the minimum hydraulic pressure required for the clutch to transmit the engine's current output torque.

[0113] When the impact stress on at least one shaft system exceeds the corresponding maximum allowable stress (i.e., τ>[τ] for one or more shaft systems), there is a risk of impact failure. A pressure reduction signal is output to control clutch disengagement. Controlling clutch disengagement specifically involves reducing the target clutch pressure to below the torque transmission pressure. When the clutch pressure is lower than the torque transmission pressure, the normal pressure between the clutch driving and driven discs decreases, making it impossible to transmit sufficient frictional torque. The clutch slips or completely disengages, interrupting torque transmission in the transmission system, thereby preventing the impact load from being transmitted along the shaft system and protecting each shaft system from damage.

[0114] Furthermore, the specific implementation method for controlling the clutch's operating state based on the comparison results includes: First, determining the clutch's target pressure based on the comparison results—when the comparison result indicates no risk of impact failure, the target pressure is set to the torque transmission pressure; when there is a risk of impact failure, the target pressure is set to a separation pressure value lower than the torque transmission pressure. Then, the hydraulic chamber pressure-displacement curve is used to determine the pressure valve spool displacement corresponding to the target pressure. The hydraulic chamber pressure-displacement curve is a pre-calibrated characteristic curve reflecting the correspondence between the piston chamber oil pressure and the pressure valve spool displacement; different spool displacements correspond to different oil pressure values. Finally, the pressure valve spool displacement is adjusted based on the clutch pressure feedback signal to make the oil pressure in the piston chamber approach the target pressure. Specifically, the oil pressure in the clutch piston chamber is collected in real time by a pressure sensor as a feedback signal, and a closed-loop control algorithm (such as PID control) is used to calculate the pressure valve spool displacement adjustment, driving the pressure valve to actuate, so that the actual oil pressure gradually approaches and stabilizes at the target pressure value, thereby achieving precise engagement and disengagement control of the clutch.

[0115] Example 2: Based on the same technical concept, Example 2 of the present invention also provides a clutch control system for a hybrid power system, such as... Figure 3 As shown, it includes: a filtering module 201, a fire condition identification module 202, a system impact calculation module 203, and a clutch control module 204, wherein:

[0116] The filtering module 201 is used to acquire the Nernst voltage value output by the pre-oxygen sensor and filter the Nernst voltage value to obtain the filtered voltage value.

[0117] The misfire condition identification module 202 is used to determine the Nernst voltage change rate based on the filtered voltage value, and to determine that the engine has misfired and output a misfire flag bit when the filtered voltage value is less than or equal to a first threshold and the Nernst voltage change rate is less than or equal to a second threshold.

[0118] The system impact calculation module 203 is used to respond to the misfire flag position and calculate the impact stress on each shaft system based on the rotational inertia of each shaft system in the hybrid power system, the change in angular velocity of each shaft system before and after engine misfire, and the structural parameters of each shaft system.

[0119] The clutch control module 204 is used to compare the impact stress on each shaft system with the maximum allowable stress of the corresponding shaft system, and control the working state of the clutch according to the comparison result. When the impact stress on each shaft system is less than or equal to the corresponding maximum allowable stress, a pressure build-up signal is output to control the clutch to maintain the engagement state. When the impact stress on at least one shaft system is greater than the corresponding maximum allowable stress, a pressure reduction signal is output to control the clutch to disengage.

[0120] In another preferred embodiment of the invention, such as Figure 4 As shown, the clutch control process involves controlling the clutch's operating state based on the comparison results.

[0121] (I) Pressure signal acquisition and control decision

[0122] When the system impact calculation module determines that the impact stress of each shaft system is less than or equal to the corresponding maximum allowable stress, it outputs a pressure build-up signal. Upon receiving this signal, the clutch control module maintains the clutch in engagement, meaning it controls the clutch's target pressure to equal the torque transmission pressure. Torque transmission pressure refers to the minimum oil pressure required for the clutch to reliably transmit power under the current engine output torque; this value can be calculated in real-time based on the engine torque and clutch parameters.

[0123] When the system impact calculation module determines that the impact stress of at least one shaft system is greater than the corresponding maximum allowable stress, it outputs a pressure reduction signal. Upon receiving the pressure reduction signal, the clutch control module controls the clutch to disengage, i.e., reduces the target pressure of the clutch to below the torque transmission pressure. When the actual clutch pressure is lower than the torque transmission pressure, the clutch cannot transmit the full torque of the engine, and relative slippage or complete disengagement occurs between the driving and driven discs, thus interrupting the torque transmission path from the engine to the transmission system.

[0124] (ii) Hydraulic pressure control

[0125] After determining the target pressure of the clutch based on the comparison results, the actual hydraulic pressure of the clutch needs to be adjusted to the target pressure. In this embodiment, a combination of hydraulic chamber pressure-displacement curve and closed-loop feedback control is used to achieve precise pressure regulation.

[0126] like Figure 5 As shown, the hydraulic chamber pressure-displacement curve is a characteristic curve calibrated beforehand through bench testing. Its horizontal axis represents the valve spool displacement, and its vertical axis represents the oil pressure within the piston chamber. Different target pressure values ​​correspond to different valve spool displacement positions. For example, the target pressure is the torque transmission pressure P. trans When, the corresponding valve core displacement is S trans The target pressure is the separation pressure P. sep When the torque is less than the transmission pressure, the corresponding valve core displacement is S. sep This curve can be stored in the memory of the electronic control unit for lookup during real-time control.

[0127] like Figure 6 As shown, the hydraulic pressure control adopts a closed-loop feedback control method. The specific process is as follows:

[0128] First, based on the target pressure value, the initial target value of the valve core displacement of the corresponding pressure valve is determined using the hydraulic chamber pressure-displacement curve.

[0129] Secondly, the actual oil pressure value is collected in real time by a pressure sensor installed in the clutch piston chamber, which serves as a feedback signal.

[0130] Then, the actual pressure value is compared with the target pressure value to calculate the deviation. The controller (e.g., a PID controller) calculates the adjustment amount of the valve core displacement based on the deviation, and controls the electromagnet or stepper motor of the pressure valve to adjust the actual displacement of the valve core through the drive circuit.

[0131] Finally, continue the above feedback adjustment process until the actual oil pressure approaches and stabilizes at the target pressure value.

[0132] The closed-loop control method described above can effectively overcome the influence of disturbances such as oil temperature changes, valve core friction, and system leakage, ensuring precise control and rapid response of clutch pressure.

[0133] When the target pressure is the torque transmission pressure, the clutch remains engaged, and the engine power is transmitted normally to the transmission system.

[0134] When the target pressure drops below the torque transmission pressure, the clutch disengages, the torque transmission of the transmission system is interrupted, and the impact load generated by engine misfire cannot be transmitted to the downstream shaft system, thus effectively protecting each shaft system from torsional impact damage.

[0135] Example 3: The technical effects of the clutch control method for a hybrid power system of the present invention will be further explained below with reference to two examples applied to real-world scenarios.

[0136] by Figure 7 Taking the six-parallel-shaft hybrid system shown as an example, when the vehicle is cruising at high speed, the engine is working normally and the Nernst voltage value of the front oxygen sensor is stable within the normal range.

[0137] When the engine suddenly misfires due to fuel quality issues, the Nernst voltage value u′ drops rapidly to the first threshold u. min Below this threshold, the rate of change of Nernst voltage Δu′ also decreases to the second threshold Δu. min The following applies. Upon detecting that both of the above conditions are met simultaneously, the fire condition identification module immediately outputs a fire flag.

[0138] After receiving the fire alarm, the system impact calculation module reads the rotational speed signal of each shaft system within a few milliseconds, calculates the change in angular velocity, and combines the pre-stored structural parameters of each shaft system (moment of inertia, shear modulus, polar moment of inertia, bearing span, torsional section modulus, cross-sectional outer diameter, inner diameter ratio, etc.) and the transmission ratio between each shaft system to calculate the impact stress of shaft system 1 to shaft system 6 according to formula (7) and formula (13).

[0139] Upon comparison, the impact stress τ4 of shaft 4 exceeded its maximum allowable stress [τ4], posing a risk of failure. The clutch control module immediately outputs a pressure reduction signal, reducing the clutch target pressure from the current torque transmission pressure to the separation pressure (e.g., reducing it by more than 50%), and quickly adjusts the actual oil pressure to the target value through closed-loop pressure control.

[0140] After the clutch disengages, the torque transmission path from the engine to the transmission system is cut off, and the impact load cannot be transmitted to shaft 4 and other shaft systems, thus effectively avoiding torsional fatigue damage or fracture failure of the shaft system. Once the engine resumes normal operation, the clutch can re-engage to restore power transmission.

[0141] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0142] In one embodiment, the present invention also provides an electronic device, which may be a terminal, and its internal structure diagram may be as follows. Figure 8As shown. The electronic device includes a processor, memory, communication interface, display screen, and input device connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When the computer program is executed by the processor, it implements the clutch control method for a hybrid power system as described in any one of steps S101 to S104. The display screen can be a liquid crystal display (LCD) or an e-ink display. The input device can be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the device's casing, or an external keyboard, touchpad, or mouse.

[0143] Those skilled in the art will understand that Figure 8 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0144] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0145] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0146] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0147] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions that, when performed on the computer or other programmable apparatus, provide for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0148] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. A clutch control method for a hybrid power system, characterized in that, include: The Nernst voltage value output by the pre-oxygen sensor is obtained, and the Nernst voltage value is filtered to obtain the filtered voltage value. The Nernst voltage change rate is determined based on the filtered voltage value, and when the filtered voltage value is less than or equal to a first threshold and the Nernst voltage change rate is less than or equal to a second threshold, it is determined that the engine has misfired and a misfire flag is output. In response to the misfire flag, the impact stress on each shaft system is calculated based on the rotational inertia of each shaft system in the hybrid power system, the change in angular velocity of each shaft system before and after engine misfire, and the structural parameters of each shaft system. The impact stress on each shaft system is compared with the maximum allowable stress of the corresponding shaft system, and the working state of the clutch is controlled according to the comparison results. When the impact stress on each shaft system is less than or equal to the corresponding maximum allowable stress, a pressure build-up signal is output to control the clutch to maintain the engagement state. When the impact stress on at least one shaft system is greater than the corresponding maximum allowable stress, a pressure reduction signal is output to control the clutch to disengage.

2. The method according to claim 1, characterized in that, The Nernst voltage value is obtained according to a preset sampling period, the filtered voltage value is obtained based on the real-time acquired Nernst voltage value, and the Nernst voltage change rate is obtained based on the filtered voltage value within adjacent sampling times or a preset time window.

3. The method according to claim 1, characterized in that, The calculation of the impact stress on each shaft system includes calculating the impact stress on each shaft system using the following formula: In the formula: Let be the torsional section modulus of shaft system 1. Let be the moment of inertia of shaft system 1. This represents the change in angular velocity of shaft system 1 before and after the engine misfire. Let be the shear modulus of shaft system 1. Let be the polar moment of inertia of axis system 1. The bearing span of shaft system 1.

4. The method according to claim 3, characterized in that, The calculation of the impact stress on each shaft system also includes calculating the impact stress on shaft system n according to the following formula: ; In the formula: Let n be the torsional section modulus of shaft system n. This represents the transmission ratio between shaft system 1 and shaft system n. Let be the outer diameter of the cross-section of shaft system 1. Let n be the outer diameter of the cross-section of shaft system n. The inner diameter ratio of shaft system 1, Let n be the ratio of the inner diameter of the shaft system n.

5. The method according to claim 4, characterized in that, The polar moment of inertia of the shaft system 1 is calculated according to the following formula: ； The torsional section modulus of shaft system 1 is calculated according to the following formula: In the formula: Let be the outer diameter of the cross-section of shaft system 1. The inner diameter ratio of shaft system 1 is the ratio of the inner diameter to the outer diameter of the shaft system.

6. The method according to claim 4, characterized in that, The polar moment of inertia of the axis system n is calculated according to the following formula: ; The torsional section modulus of the shaft system n is calculated according to the following formula: ; In the formula: Let n be the outer diameter of the cross-section of shaft system n. Let be the ratio of the inner diameter of shaft system n, which is the ratio of the inner diameter to the outer diameter of the shaft system.

7. The method according to claim 1, characterized in that, The control of the clutch to maintain engagement includes: controlling the target pressure of the clutch to be equal to the torque transmission pressure; the control of the clutch to disengage includes: controlling the target pressure of the clutch to decrease to less than the torque transmission pressure.

8. The method according to claim 1, characterized in that, The step of controlling the working state of the clutch based on the comparison result includes: determining the target pressure of the clutch based on the comparison result, determining the pressure valve core displacement corresponding to the target pressure using the hydraulic chamber pressure-displacement curve, and adjusting the pressure valve core displacement based on the clutch pressure feedback signal so that the oil pressure in the piston chamber approaches the target pressure.

9. A clutch control system for a hybrid power system, characterized in that, include: The filtering module is used to obtain the Nernst voltage value output by the pre-oxygen sensor and to filter the Nernst voltage value to obtain the filtered voltage value. The misfire condition identification module is used to determine the Nernst voltage change rate based on the filtered voltage value, and to determine that the engine has misfired and output a misfire flag bit when the filtered voltage value is less than or equal to a first threshold and the Nernst voltage change rate is less than or equal to a second threshold. The system impact calculation module is used to calculate the impact stress on each shaft system in response to the misfire flag, based on the rotational inertia of each shaft system in the hybrid power system, the change in angular velocity of each shaft system before and after engine misfire, and the structural parameters of each shaft system. The clutch control module is used to compare the impact stress on each shaft system with the maximum allowable stress of the corresponding shaft system, and control the working state of the clutch according to the comparison result. Specifically, when the impact stress on each shaft system is less than or equal to the corresponding maximum allowable stress, a pressure build-up signal is output to control the clutch to maintain the engagement state; when the impact stress on at least one shaft system is greater than the corresponding maximum allowable stress, a pressure reduction signal is output to control the clutch to disengage.

10. An electronic device, characterized in that, The electronic device includes: At least one processor; and a memory communicatively connected to said at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor to enable the at least one processor to perform the method of any one of claims 1 to 8.

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