Hybrid vehicle clutch control method

Abstract

The present disclosure provides a hybrid vehicle clutch control method, which comprises: acquiring current vehicle driving data, judging whether the current driving demand is a power demand, if the current driving demand is a power demand, judging whether the current maximum available driving capacity meets the condition of clutch power disconnection or clutch power connection; if the current maximum available driving capacity meets the condition of clutch power disconnection or clutch power connection, judging the clutch target state; if the clutch target state is clutch connection, performing clutch power connection operation; if the clutch target state is clutch disconnection, performing clutch power disconnection operation. The hybrid vehicle clutch control method provided by the present disclosure distinguishes the power demand and non-power demand of clutch switching by analyzing the driving demand during driving, adjusts the control target of the clutch, and meets the differentiated demand under different driving conditions.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of hybrid electric vehicles, in particular to a clutch control method for hybrid electric vehicles. BACKGROUND

[0002] With the rapid development of the hybrid electric vehicle market, various hybrid products are increasing. In order to improve economy, the general hybrid strategy adopts motor driving at low vehicle speed and engine direct driving at medium-high vehicle speed. This driving mode is usually realized through clutch control. Therefore, whether the clutch engagement and disengagement is timely and smooth directly affects the driving experience.

[0003] The current clutch control method adjusts the speed of the input shaft side of the clutch through torque or speed command when the clutch needs to be engaged, so that it approaches the speed of the output shaft. When the speed difference between the two is less than a certain value, it is considered that synchronization is completed, and the clutch engagement command is issued to control the clutch to be pressed and engaged. When the torque or speed command adjusts the speed of the input shaft side of the clutch, so that it approaches the speed of the output shaft, when the speed difference between the two is less than a certain value, it is considered that synchronization is completed, and the clutch engagement command is issued to control the clutch to be pressed and engaged. This control method has a single control target, and requires a certain execution time when the torque is unloaded, the speed is synchronized, and the torque is loaded. It also cannot meet different driving needs under different driving conditions. SUMMARY

[0004] The purpose of the present disclosure is to provide a clutch control method for hybrid electric vehicles, which can solve one or more of the above-mentioned problems in the prior art.

[0005] The present disclosure provides a clutch control method for hybrid electric vehicles, comprising:

[0006] Obtaining current vehicle driving data, determining whether the current driving demand is a power demand,

[0007] If the current driving demand is a non-power demand, performing a clutch non-power disengagement operation or a clutch non-power engagement operation;

[0008] If the current driving demand is a power demand, determining whether the current maximum available driving capacity meets the conditions for clutch power disengagement or clutch power engagement;

[0009] If the current maximum available driving capacity does not meet the conditions for clutch power disengagement or clutch power engagement, the clutch does not act;

[0010] If the current maximum available driving capacity meets the conditions for clutch power disengagement or clutch power engagement, the clutch target state is determined;

[0011] If the clutch target state is clutch engagement, clutch power engagement operation is performed;

[0012] If the clutch target state is clutch disengagement, clutch power disengagement operation is performed.

[0013] In some embodiments, current vehicle driving data is acquired, and it is determined whether the current driving demand is a power demand, comprising:

[0014] The vehicle gear and vehicle speed are acquired, and it is determined whether the current vehicle is in a driving state and whether the current vehicle speed is greater than a first preset value,

[0015] If the current vehicle is not in a drive gear or the current vehicle speed is not greater than the first preset value, it is determined that the current driving demand is a non-power demand;

[0016] If the current vehicle is in a drive gear and the current vehicle speed is greater than the first preset value, it is determined whether the current vehicle speed is within a preset first vehicle speed range,

[0017] If the current vehicle speed is not within the preset first vehicle speed range, it is determined that the current driving demand is a non-power demand;

[0018] If the current vehicle speed is within the preset first vehicle speed range, the current accelerator pedal opening and the accelerator pedal opening rate of change are acquired, and it is determined whether the current accelerator pedal opening is greater than a second preset value and the accelerator pedal opening rate of change is greater than a third preset value;

[0019] If the current accelerator pedal opening is not greater than the second preset value or the accelerator pedal opening rate of change is not greater than the third preset value, it is determined that the current driving demand is a non-power demand;

[0020] If the current accelerator pedal opening is greater than the second preset value and the accelerator pedal opening rate of change is greater than the third preset value, it is determined that the current driving demand is a power demand.

[0021] In some embodiments, the clutch non-power disengagement operation comprises:

[0022] Unloading the clutch front-end torque,

[0023] Setting the engine target torque to zero torque,

[0024] Setting the generator target torque to zero torque,

[0025] Driving the motor to perform a driving demand torque and dynamically compensating for an engine response delay part;

[0026] Determining whether the clutch front-end torque is unloaded,

[0027] If the clutch front-end torque is unloaded, the clutch is disengaged;

[0028] If the clutch front end torque unloading is not completed, the clutch does not act;

[0029] After the clutch is disconnected, the generator is set to the speed mode, and the target speed of the generator is the target speed after the clutch is disconnected.

[0030] In some embodiments, the clutch non-powerful combination operation includes:

[0031] The generator connected to the engine is set to the speed mode, and the target speed of the generator is set to the target speed after the clutch is connected;

[0032] The engine target torque is set to zero torque,

[0033] It is judged whether the absolute value of the difference between the real-time speed of the generator and the target speed after the clutch is connected is less than a fourth preset value and the change rate of the generator speed is less than a fifth preset value;

[0034] If the absolute value of the difference between the real-time speed of the generator and the target speed after the clutch is connected is not less than the fourth preset value or the change rate of the generator speed is not less than the fifth preset value, the clutch does not act;

[0035] If the absolute value of the difference between the real-time speed of the generator and the target speed after the clutch is connected is less than the fourth preset value and the change rate of the generator speed is less than the fifth preset value, the clutch is connected.

[0036] After the clutch is connected, the generator is set to the torque mode, and the engine target torque is the target torque after the clutch is connected.

[0037] In some embodiments, judging whether the current maximum available driving capacity meets the condition of the clutch powerful disconnection or the clutch powerful connection includes:

[0038] The maximum available driving capacity Pms when the clutch is disconnected and the maximum available driving capacity Pmp when the clutch is connected are calculated respectively;

[0039] The maximum available driving capacity Pms when the clutch is disconnected and the maximum available driving capacity Pmp when the clutch is connected are compared;

[0040] If the difference between the maximum available driving capacity Pms when the clutch is disconnected and the maximum available driving capacity Pmp when the clutch is connected is a positive number and the difference is greater than a sixth preset value, it is determined that the driving capacity of the clutch disconnection is greater than the driving capacity of the clutch connection, and the condition of the clutch powerful disconnection or the clutch powerful connection is met;

[0041] If the difference between the maximum available driving capability Pms when the clutch is disconnected and the maximum available driving capability Pmp when the clutch is connected is negative and the absolute value of the difference is greater than a seventh preset value, it is determined that the driving capability when the clutch is disconnected is less than the driving capability when the clutch is connected, satisfying the condition of clutch power disconnection or clutch power connection.

[0042] If the difference between the maximum available driving capability Pms when the clutch is disconnected and the maximum available driving capability Pmp when the clutch is connected is positive and the difference is not greater than a sixth preset value, or the difference between the maximum available driving capability Pms when the clutch is disconnected and the maximum available driving capability Pmp when the clutch is connected is negative and the absolute value of the difference is not greater than a seventh preset value, it is determined that the driving capability when the clutch is disconnected is equal to the driving capability when the clutch is connected, not satisfying the condition of clutch power disconnection or clutch power connection.

[0043] In some embodiments, calculating the maximum available driving capability Pms when the clutch is disconnected comprises:

[0044] The maximum torque at the input end of the generator at different engine speeds is obtained by multiplying the maximum net output torque of the engine at different speeds by the generator transmission ratio and the generator transmission efficiency;

[0045] The maximum torque at the input end of the generator at different speeds is taken as the minimum of the maximum torque at the input end of the generator at different speeds and the absolute value of the generator external characteristic, to obtain the maximum available torque for series generation at different speeds,

[0046] The maximum available torque for series generation, the speed corresponding to the maximum available torque for series generation, and the generator system efficiency are calculated to obtain the maximum available power for series generation at different speeds;

[0047] The maximum value of the calculated maximum available power for series generation is selected as the maximum available power for generation;

[0048] The maximum available driving electrical power Pes when the clutch is disconnected can be obtained by adding the available discharging power of the battery to the maximum available power for generation and subtracting the accessory consumption power;

[0049] The input electrical power of the drive motor at different torques is calculated by discretizing the available torque corresponding to the current speed of the drive motor and the corresponding drive motor system efficiency;

[0050] The value closest to the maximum available driving electrical power Pes when the clutch is disconnected is selected from the input electrical power of the drive motor at different torques, and the mechanical power Pms of the drive motor, i.e. the maximum available driving capability Pms when the clutch is disconnected, is calculated according to the torque point corresponding to the selected input electrical power of the drive motor.

[0051] In some embodiments, calculating the maximum available driving capability Pmp when the clutch is connected comprises:

[0052] The current engine maximum available power is calculated by using the engine speed corresponding to the current vehicle speed and the maximum net output torque of the engine at the speed;

[0053] The maximum engine driving capacity Pmp1 when the clutch is engaged is obtained by multiplying the current engine maximum available power by the transmission efficiency driven by the engine;

[0054] The maximum available driving electric power Pep when the clutch is engaged is obtained by subtracting the accessory power consumption from the available discharging power of the battery;

[0055] The driving electric motor input electric power at different torques is calculated by discretizing the available torque corresponding to the current driving electric motor speed and the corresponding driving electric motor system efficiency;

[0056] The value closest to the maximum available driving electric power Pep when the clutch is engaged is selected from the driving electric motor input electric power at different torques, and the maximum available driving capacity Pmp2 of the driving electric motor at the current working condition when the clutch is engaged is calculated according to the torque point corresponding to the selected driving electric motor input electric power;

[0057] The maximum available driving capacity Pmp of the clutch when the clutch is engaged is Pmp1+Pmp2.

[0058] In some embodiments, determining the clutch target state comprises:

[0059] The current vehicle speed and vehicle demand torque are obtained, and the driver driving demand power Pd is calculated;

[0060] The current clutch state is obtained,

[0061] If the current clutch state is disengaged, it is determined whether the driver driving demand power Pd plus a first offset is greater than the maximum available driving capacity Pms when the clutch is disengaged,

[0062] If the driver driving demand power Pd plus the first offset is greater than the maximum available driving capacity Pms when the clutch is disengaged, the clutch target state is clutch engagement;

[0063] If the driver driving demand power Pd plus the first offset is not greater than the maximum available driving capacity Pms when the clutch is disengaged, the clutch target state is clutch disengagement;

[0064] If the current clutch state is engaged, it is determined whether the driver driving demand power Pd plus a second offset is greater than the maximum available driving capacity Pmp when the clutch is engaged,

[0065] If the driver driving demand power Pd plus the second offset is greater than the maximum available driving capacity Pmp when the clutch is engaged, the clutch target state is clutch disengagement;

[0066] If the driver demand power Pd plus the second offset is not greater than the maximum available drive capability Pmp when the clutch is engaged, the clutch target state is clutch engaged.

[0067] In some embodiments, the clutch power-off operation includes:

[0068] Setting the engine torque target to the target torque after the clutch is disengaged;

[0069] The generator generates negative torque corresponding to the positive torque of the engine, and the motor executes the drive demand torque;

[0070] Determining the size relationship between the absolute value of the engine torque plus the generator torque and the eighth preset value, if the absolute value of the engine torque plus the generator torque is not less than the eighth preset value, the clutch does not act, if the absolute value of the engine torque plus the generator torque is less than the eighth preset value, the clutch is disengaged;

[0071] After the clutch is disengaged, the generator is set to the speed mode, and the target speed of the generator is the target speed when the clutch is disengaged.

[0072] In some embodiments, the clutch power-off operation includes:

[0073] Setting the generator connected to the engine to the speed mode, and the target speed of the generator is the target generator speed after the clutch is engaged;

[0074] Obtaining the current engine speed, and determining the size relationship between the target engine speed after the clutch is engaged and the current engine speed;

[0075] If the target engine speed when the clutch is engaged is greater than the current engine speed, and the target engine speed when the clutch is engaged minus the actual generator speed is not less than the ninth preset value, the engine torque target is controlled to the target torque after the clutch is engaged;

[0076] If the target engine speed when the clutch is engaged is less than the current engine speed, and the actual generator speed minus the target engine speed when the clutch is engaged is not less than the ninth preset value, the current engine power is calculated using the engine speed and torque, if the calculated current engine power is greater than the peak power of the generator connected to the engine minus the third offset, the engine target torque is controlled to the first target torque;

[0077] If the absolute value of the current engine speed minus the target engine speed when the clutch is engaged is less than the ninth preset value, the clutch is engaged;

[0078] After the clutch is engaged, the generator is set to the torque mode.

[0079] The hybrid vehicle clutch control method provided by the present disclosure distinguishes power demand and non-power demand of clutch switching by analyzing driving demand during driving, adjusts the control target of the clutch, and is fast when the clutch is switched under power demand and stable and reliable when the clutch is switched under non-power demand, thereby meeting differentiated demand under different driving conditions. BRIEF DESCRIPTION OF DRAWINGS

[0080] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without creative labor.

[0081] Figure 1 The flowchart of the hybrid vehicle clutch control method provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0082] In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be described clearly and completely in combination with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are some embodiments of the present disclosure, not all embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present disclosure.

[0083] Embodiment:

[0084] In the present embodiment, referring to the drawings in the specification Figure 1 , a hybrid vehicle clutch control method is provided, which specifically includes the following steps:

[0085] Obtain current vehicle driving data, and determine whether the current driving demand is power demand,

[0086] If the current driving demand is non-power demand, perform clutch non-power disconnection operation or clutch non-power connection operation;

[0087] If the current driving demand is power demand, determine whether the current maximum available driving capacity meets the condition of clutch power disconnection or clutch power connection;

[0088] If the current maximum available driving capacity does not meet the condition of clutch power disconnection or clutch power connection, the clutch does not act;

[0089] If the current maximum available driving capacity meets the condition of the clutch power disengagement or the clutch power engagement, the clutch target state is determined;

[0090] If the clutch target state is the clutch engagement, the clutch power engagement operation is performed.

[0091] If the clutch target state is the clutch disengagement, the clutch power disengagement operation is performed.

[0092] In an optional embodiment, if the current driving demand is the non-power demand, whether the clutch target state is the engagement or the disengagement can be determined according to the current vehicle speed and the vehicle demand power by table lookup.

[0093] Specifically, the determination method of the two-dimensional table used in the table lookup includes the following steps:

[0094] The vehicle demand power is divided into a plurality of discrete power points according to a predetermined interval;

[0095] The vehicle speed is divided into a plurality of discrete vehicle speed points according to a predetermined interval;

[0096] When the vehicle speed exceeds the vehicle speed range of the clutch parallel connection, i.e., the vehicle speed is lower than the minimum vehicle speed at which the engine can work stably or the vehicle speed is higher than the critical vehicle speed at which the engine is overspeed, the clutch target state is the disengagement;

[0097] When the vehicle speed does not exceed the vehicle speed range of the clutch parallel connection, the clutch target state can be any one of the disengagement or the engagement, i.e., the current clutch can be in the series mode or the parallel mode, then the fuel consumption of the clutch disengagement state and the clutch engagement state is calculated for each discrete vehicle demand power point and each discrete vehicle speed point, and the state with lower fuel consumption is selected as the clutch target state in the calculation results;

[0098] The power point, the vehicle speed point and the clutch target state are integrated into a two-dimensional table related to the vehicle demand power, the vehicle speed and the clutch target state.

[0099] Among them, the clutch engagement state corresponds to the clutch parallel mode, and the clutch disengagement state corresponds to the clutch series mode.

[0100] In an optional embodiment, obtaining the current vehicle driving data and determining whether the current driving demand is the power demand can include:

[0101] Obtaining the vehicle gear and the vehicle speed, and determining whether the current vehicle is in the driving state and whether the current vehicle speed is greater than a first preset value,

[0102] If the current vehicle is not in the drive gear or the current vehicle speed is not greater than the first preset value, it is determined that the current driving demand is the non-power demand;

[0103] if the current vehicle is in the drive gear and the current vehicle speed is greater than the first preset value, determining whether the current vehicle speed is in a preset first vehicle speed range,

[0104] if the current vehicle speed is not in the preset first vehicle speed range, determining that the current driving demand is a non-power demand;

[0105] if the current vehicle speed is in the preset first vehicle speed range, obtaining the current accelerator pedal opening degree and the accelerator pedal opening degree change rate, and determining whether the current accelerator pedal opening degree is greater than a second preset value and the accelerator pedal opening degree change rate is greater than a third preset value;

[0106] if the current accelerator pedal opening degree is not greater than the second preset value or the accelerator pedal opening degree change rate is not greater than the third preset value, determining that the current driving demand is a non-power demand;

[0107] if the current accelerator pedal opening degree is greater than the second preset value and the accelerator pedal opening degree change rate is greater than the third preset value, determining that the current driving demand is a power demand.

[0108] In an optional embodiment, the clutch non-power disengagement operation can include:

[0109] unloading the clutch front end torque,

[0110] setting the engine target torque to zero torque,

[0111] setting the generator target torque to zero torque,

[0112] driving the motor to execute a driving demand torque and dynamically compensating for an engine response delay part;

[0113] determining whether the clutch front end torque unloading is completed,

[0114] if the clutch front end torque unloading is completed, disengaging the clutch;

[0115] if the clutch front end torque unloading is not completed, the clutch is not actuated;

[0116] after the clutch is disengaged, setting the generator to a speed mode, and the target speed of the generator is the target speed after the clutch is disengaged.

[0117] In an optional embodiment, the clutch non-power engagement operation can include:

[0118] setting the generator connected to the engine to a speed mode, and the target speed of the generator is set to the target speed after the clutch is engaged;

[0119] setting the engine target torque to zero torque,

[0120] determining whether the absolute value of the difference between the real-time speed of the generator and the target speed of the clutch after being combined is less than a fourth preset value and whether the change rate of the generator speed is less than a fifth preset value;

[0121] if the absolute value of the difference between the real-time speed of the generator and the target speed of the clutch after being combined is not less than the fourth preset value or the change rate of the generator speed is not less than the fifth preset value, the clutch does not actuate;

[0122] if the absolute value of the difference between the real-time speed of the generator and the target speed of the clutch after being combined is less than the fourth preset value and the change rate of the generator speed is less than the fifth preset value, the clutch is combined;

[0123] after the clutch is combined, the generator is set to a torque mode, and the target torque of the engine is the target torque after the clutch is combined.

[0124] In an optional embodiment, determining whether the current maximum available driving capability meets the condition for power-off disconnection or power-on combination of the clutch includes:

[0125] respectively calculating the maximum available driving capability Pms when the clutch is disconnected and the maximum available driving capability Pmp when the clutch is combined;

[0126] comparing the maximum available driving capability Pms when the clutch is disconnected and the maximum available driving capability Pmp when the clutch is combined;

[0127] if the difference between the maximum available driving capability Pms when the clutch is disconnected and the maximum available driving capability Pmp when the clutch is combined is a positive number and the difference is greater than a sixth preset value, it is determined that the driving capability when the clutch is disconnected is greater than the driving capability when the clutch is combined, and the condition for power-off disconnection or power-on combination of the clutch is met;

[0128] if the difference between the maximum available driving capability Pms when the clutch is disconnected and the maximum available driving capability Pmp when the clutch is combined is a negative number and the absolute value of the difference is greater than a seventh preset value, it is determined that the driving capability when the clutch is disconnected is less than the driving capability when the clutch is combined, and the condition for power-off disconnection or power-on combination of the clutch is met;

[0129] if the difference between the maximum available driving capability Pms when the clutch is disconnected and the maximum available driving capability Pmp when the clutch is combined is a positive number and the difference is not greater than the sixth preset value, or the difference between the maximum available driving capability Pms when the clutch is disconnected and the maximum available driving capability Pmp when the clutch is combined is a negative number and the absolute value of the difference is not greater than the seventh preset value, it is determined that the driving capability when the clutch is disconnected is equal to the driving capability when the clutch is combined, and the condition for power-off disconnection or power-on combination of the clutch is not met.

[0130] Specifically, calculating the maximum available driving capability Pms when the clutch is disconnected includes:

[0131] The maximum torque of the engine at different speeds is multiplied by the power generation transmission ratio and the power generation transmission efficiency to obtain the maximum torque of the generator input end at different speeds;

[0132] The maximum torque of the generator input end at different speeds is compared with the absolute value of the generator external characteristic, and the smaller one is taken as the maximum available torque of the series power generation at different speeds,

[0133] The maximum available torque of the series power generation, the corresponding speed of the maximum available torque of the series power generation, and the generator system efficiency are calculated to obtain the maximum available power of the series power generation at different speeds;

[0134] The maximum value of the calculated maximum available power of the series power generation is selected as the maximum available power of the power generation;

[0135] The maximum available power of the power generation is added to the available discharge power of the battery and then subtracted by the accessory consumption power to obtain the maximum available drive electric power Pes when the clutch is disconnected;

[0136] The available torque corresponding to the current speed of the drive motor is discretized, and the drive motor input electric power at different torques is calculated according to the corresponding drive motor system efficiency;

[0137] The value closest to the maximum available drive electric power Pes when the clutch is disconnected is selected from the drive motor input electric power at different torques, and the mechanical power Pms of the drive motor is calculated according to the torque point corresponding to the selected drive motor input electric power, that is, the maximum available drive capacity Pms when the clutch is disconnected.

[0138] Specifically, calculating the maximum available drive capacity Pmp when the clutch is engaged includes:

[0139] The maximum available power of the current engine is calculated according to the corresponding engine speed at the current speed and the maximum net output torque of the engine at this speed;

[0140] The maximum available power of the current engine is multiplied by the transmission efficiency of the engine drive to obtain the maximum drive capacity Pmp1 of the engine when the clutch is engaged;

[0141] The maximum available drive electric power Pep when the clutch is engaged is obtained by subtracting the accessory consumption power from the available discharge power of the battery;

[0142] The available torque corresponding to the current speed of the drive motor is discretized, and the drive motor input electric power at different torques is calculated according to the corresponding drive motor system efficiency;

[0143] selecting a value closest to the maximum available driving electric power Pep when the clutch is engaged from the driving electric motor input electric power at different torques, and calculating the driving electric motor mechanical power Pmp2 according to the torque point corresponding to the selected driving electric motor input electric power, that is, the maximum available driving capability of the driving electric motor when the clutch is engaged in the current working condition;

[0144] The maximum available driving capability Pmp of the clutch is Pmp1+Pmp2.

[0145] In an optional embodiment, determining the target state of the clutch comprises:

[0146] obtaining the current vehicle speed and the vehicle demand torque, and calculating the driver driving demand power Pd;

[0147] obtaining the current clutch state,

[0148] if the current clutch state is disengaged, determining whether the driver driving demand power Pd plus a first offset is greater than the maximum available driving capability Pms when the clutch is disengaged,

[0149] if the driver driving demand power Pd plus the first offset is greater than the maximum available driving capability Pms when the clutch is disengaged, the target state of the clutch is that the clutch is engaged;

[0150] if the driver driving demand power Pd plus the first offset is not greater than the maximum available driving capability Pms when the clutch is disengaged, the target state of the clutch is that the clutch is disengaged;

[0151] if the current clutch state is engaged, determining whether the driver driving demand power Pd plus a second offset is greater than the maximum available driving capability Pmp when the clutch is engaged,

[0152] if the driver driving demand power Pd plus the second offset is greater than the maximum available driving capability Pmp when the clutch is engaged, the target state of the clutch is that the clutch is disengaged;

[0153] if the driver driving demand power Pd plus the second offset is not greater than the maximum available driving capability Pmp when the clutch is engaged, the target state of the clutch is that the clutch is engaged.

[0154] In an optional embodiment, the clutch power-off operation comprises:

[0155] setting the engine torque target to the target torque after the clutch is disengaged;

[0156] the generator generates electricity to offset the positive torque of the engine so that the action of the clutch does not transmit excess torque to the drive shaft, and the driving electric motor executes the driving demand torque;

[0157] determining the absolute value of the engine torque plus the generator torque and the eighth preset value, if the absolute value of the engine torque plus the generator torque is not less than the eighth preset value, the clutch is not operated, if the absolute value of the engine torque plus the generator torque is less than the eighth preset value, the clutch is disconnected;

[0158] setting the generator to the speed mode after the clutch is disconnected, and the target speed of the generator is the target speed of the clutch when the clutch is disconnected.

[0159] In an optional embodiment, the clutch power combination operation comprises:

[0160] setting the generator connected to the engine to the speed mode, and the target speed of the generator is the target generator speed after the clutch is combined;

[0161] obtaining the current engine speed, and determining the size relationship between the target engine speed after the clutch is combined and the current engine speed;

[0162] if the target engine speed when the clutch is combined is greater than the current engine speed, and the target engine speed when the clutch is combined minus the actual generator speed is not less than the ninth preset value, the engine torque target is controlled to be the target torque after the clutch is combined;

[0163] if the target engine speed when the clutch is combined is less than the current engine speed, and the actual generator speed minus the target engine speed when the clutch is combined is not less than the ninth preset value, the current engine power is calculated using the current engine speed and torque, if the calculated current engine power is greater than the peak power of the generator connected to the engine minus the third offset, the engine target torque is controlled to be the first target torque;

[0164] if the absolute value of the current engine speed minus the target engine speed when the clutch is combined is less than the ninth preset value, the clutch is combined;

[0165] setting the generator to the torque mode after the clutch is combined.

[0166] Specifically, the first target torque is equal to the peak power of the generator minus the third offset, multiplied by 9550, divided by the current engine speed.

[0167] The hybrid vehicle clutch control method provided by the present disclosure distinguishes between power switching demand and non-power switching demand of the clutch by analyzing driving demand during driving, adjusts the control target of the clutch, and is fast when the clutch is switched under power demand, and is smooth and reliable when the clutch is switched under non-power demand, thereby meeting the differentiated demand under different driving conditions.

[0168] The sequence of the above-described embodiments of the present specification is only for description, and does not represent the advantages and disadvantages of the embodiments. And the above-described embodiments of the present specification are described. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in a different order than the order in which they are recited in the embodiments and still achieve desirable results. In addition, the processes depicted in the figures do not necessarily require the particular order shown, or sequential order, to achieve the desired results. In some implementations, multitasking and parallel processing can be advantageous or possible.

[0169] Each of the embodiments in the present specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the difference from other embodiments. In particular, for the system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the part of the method embodiments.

[0170] A person of ordinary skill in the art can understand that all or part of the steps of the above-described embodiments can be completed by hardware, or by program instructing relevant hardware to complete, and the program can be stored in a computer readable storage medium. The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0171] The above is only a preferred embodiment of the present disclosure, and is not intended to limit the present disclosure. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A clutch control method for hybrid electric vehicles, characterized in that, include: Obtain current vehicle driving data to determine if the current driving demand is a power-related demand. If the current driving requirement is non-power requirement, then perform a non-power disengagement or non-power engagement of the clutch. If the current driving demand is a power demand, then determine whether the current maximum available driving capacity meets the conditions for clutch power disengagement or clutch power engagement. If the current maximum available driving capacity does not meet the conditions for the clutch to be dynamically disengaged or dynamically engaged, the clutch will not operate. If the current maximum available driving capacity meets the conditions for the clutch to be either dynamically disengaged or dynamically engaged, then the clutch target state is determined. If the target state of the clutch is clutch engagement, then perform the clutch power engagement operation; If the target state of the clutch is clutch disengagement, then perform a clutch power disengagement operation; The step of obtaining current vehicle driving data and determining whether the current driving demand is a power demand includes: Obtain the vehicle's gear and speed, determine whether the vehicle is currently in motion and whether the current speed exceeds a first preset value. If the vehicle is not in drive mode or the current speed is not greater than the first preset value, the current driving demand is determined to be a non-power demand. If the vehicle is currently in drive mode and the current speed is greater than a first preset value, determine whether the current speed is within the preset first speed range. If the current vehicle speed is not within the preset first speed range, the current driving demand is determined to be a non-power demand; If the current vehicle speed is within the preset first vehicle speed range, then obtain the current accelerator pedal opening and the accelerator pedal opening change rate, and determine whether the current accelerator pedal opening is greater than the second preset value and whether the accelerator pedal opening change rate is greater than the third preset value. If the current accelerator pedal opening is not greater than the second preset value or the accelerator pedal opening change rate is not greater than the third preset value, the current driving demand is determined to be a non-power demand. If the current accelerator pedal opening is greater than the second preset value and the rate of change of the accelerator pedal opening is greater than the third preset value, the current driving demand is determined to be a power demand.

2. The hybrid vehicle clutch control method according to claim 1, characterized in that, Non-powered clutch disengagement operations include: Unload the clutch front torque. Set the engine target torque to zero torque. Set the generator target torque to zero torque. The drive motor executes the required torque and dynamically compensates for the engine's response delay. Determine if the torque at the front end of the clutch has been completely unloaded. Once the torque at the front end of the clutch has been completely unloaded, the clutch disengages. If the torque at the front end of the clutch is not completely unloaded, the clutch will not engage; After the clutch is disengaged, the generator is set to speed mode, and the target speed of the generator is the target speed after the clutch is disengaged.

3. The hybrid vehicle clutch control method according to claim 1, characterized in that, Non-powered clutch engagement operations include: Set the generator connected to the engine to speed mode, and set the generator's target speed to the target speed after the clutch is engaged; Set the engine target torque to zero torque. Determine whether the absolute value of the difference between the real-time generator speed and the target speed after the clutch is engaged is less than the fourth preset value and whether the rate of change of the generator speed is less than the fifth preset value. If the absolute value of the difference between the real-time generator speed and the target speed after the clutch is engaged is not less than the fourth preset value or the rate of change of the generator speed is not less than the fifth preset value, the clutch will not engage. If the absolute value of the difference between the real-time generator speed and the target speed after the clutch is engaged is less than the fourth preset value and the rate of change of the generator speed is less than the fifth preset value, the clutch is engaged. After the clutch is engaged, the generator is set to torque mode, and the engine target torque is the target torque after the clutch is engaged.

4. The hybrid electric vehicle clutch control method according to claim 1, characterized in that, Determining whether the current maximum available driving capacity meets the conditions for clutch dynamic disengagement or clutch dynamic engagement includes: Calculate the maximum available driving capacity Pms when the clutch is disengaged and the maximum available driving capacity Pmp when the clutch is engaged, respectively. Compare the maximum available driving capacity Pms when the clutch is disengaged and the maximum available driving capacity Pmp when the clutch is engaged. If the difference between the maximum available driving capacity Pms when the clutch is disengaged and the maximum available driving capacity Pmp when the clutch is engaged is positive and the difference is greater than the sixth preset value, then it is determined that the driving capacity when the clutch is disengaged is greater than the driving capacity when the clutch is engaged, thus satisfying the conditions for the clutch to be either dynamically disengaged or dynamically engaged. If the difference between the maximum available driving capacity Pms when the clutch is disengaged and the maximum available driving capacity Pmp when the clutch is engaged is negative and the absolute value of the difference is greater than the seventh preset value, then it is determined that the driving capacity when the clutch is disengaged is less than the driving capacity when the clutch is engaged, thus satisfying the conditions for the clutch to be either dynamically disengaged or dynamically engaged. If the difference between the maximum available driving capacity Pms when the clutch is disengaged and the maximum available driving capacity Pmp when the clutch is engaged is positive and the difference is not greater than the sixth preset value, or if the difference between the maximum available driving capacity Pms when the clutch is disengaged and the maximum available driving capacity Pmp when the clutch is engaged is negative and the absolute value of the difference is not greater than the seventh preset value, then it is determined that the driving capacity when the clutch is disengaged is equal to the driving capacity when the clutch is engaged, and the conditions for clutch power disengagement or clutch power engagement are not met.

5. The hybrid vehicle clutch control method according to claim 4, characterized in that, The calculation of the maximum available drive capability Pms when the clutch is disengaged includes: The maximum torque at the generator input at different speeds is obtained by multiplying the maximum net output torque of the engine at different speeds by the generator transmission ratio and the generator transmission efficiency. By taking the smaller of the absolute values ​​of the generator's input torque and the generator's external characteristics at different speeds, we can obtain the maximum usable torque for series generation at different speeds. The maximum available torque of series power generation, the speed corresponding to the maximum available torque of series power generation, and the efficiency of the generator system are calculated to obtain the maximum available power of series power generation at different speeds. The maximum value among the calculated maximum available power of series power generation is selected as the maximum available power of power generation. The maximum available drive power Pes when the clutch is disengaged can be obtained by adding the maximum available power of the generator to the available discharge power of the battery and subtracting the power consumed by the accessories. Discretize the available torque corresponding to the current speed of the drive motor and calculate the input power of the drive motor under different torques by combining it with the corresponding drive motor system efficiency. The value closest to the maximum available drive power Pes when the clutch is disengaged is selected from the input power of the drive motor under different torques. The mechanical power Pms of the drive motor is calculated based on the torque point corresponding to the selected input power of the drive motor, which is the maximum available drive capacity Pms when the clutch is disengaged.

6. The hybrid vehicle clutch control method according to claim 4, characterized in that, The calculation of the maximum available drive capacity Pmp when the clutch is engaged includes: The maximum available power of the engine at the current vehicle speed is calculated using the engine speed corresponding to the current vehicle speed and the maximum net output torque of the engine at this speed. The maximum available power of the engine is multiplied by the transmission efficiency of the engine drive to obtain the maximum driving capacity of the engine when the clutch is engaged, Pmp1. The maximum available drive power Pep when the clutch is engaged is obtained by subtracting the power consumed by the accessory from the available discharge power of the battery. The input power of the drive motor under different torques is obtained by discretizing the available torque corresponding to the current speed of the drive motor and calculating the corresponding drive motor system efficiency. Select the value closest to the maximum available drive power Pep when the clutch is engaged from the input power of the drive motor under different torque conditions. Calculate the mechanical power Pmp2 of the drive motor based on the torque point corresponding to the selected input power of the drive motor, which is the maximum available drive capacity of the drive motor when the clutch is engaged under the current operating conditions. When the clutch is engaged, the maximum available driving capacity Pmp = Pmp1 + Pmp2.

7. The hybrid electric vehicle clutch control method according to claim 4, characterized in that, The determination of the clutch target state includes: Obtain the current vehicle speed and required torque, and calculate the driver's required driving power Pd; Get the current clutch status. If the current clutch state is disengaged, determine whether the driver's drive demand power Pd plus the first offset is greater than the maximum available drive capacity Pms when the clutch is disengaged. If the driver's driving power demand Pd plus the first offset is greater than the maximum available driving capacity Pms when the clutch is disengaged, then the clutch target state is clutch engagement. If the driver's driving power demand Pd plus the first offset is not greater than the maximum available driving capacity Pms when the clutch is disengaged, then the clutch target state is clutch disengagement. If the current clutch state is engaged, determine whether the driver's drive demand power Pd plus the second offset is greater than the maximum available drive capacity Pmp when the clutch is engaged. If the driver's driving power demand Pd plus the second offset is greater than the maximum available driving capacity Pmp when the clutch is engaged, then the clutch target state is clutch disengagement. If the driver's driving power demand Pd plus the second offset is not greater than the maximum available driving capacity Pmp when the clutch is engaged, then the clutch target state is clutch engagement.

8. The hybrid vehicle clutch control method according to claim 1, characterized in that, The clutch power disengagement operation includes: Set the engine torque target to the target torque after the clutch is disengaged; The generator generates electricity using the negative torque corresponding to the positive torque of the engine, which drives the motor to execute the required torque. Determine the relationship between the absolute value of the engine torque plus the generator torque and the eighth preset value. If the absolute value of the engine torque plus the generator torque is not less than the eighth preset value, the clutch does not engage; if the absolute value of the engine torque plus the generator torque is less than the eighth preset value, the clutch disengages. After the clutch is disengaged, the generator is set to speed mode, and the target speed of the generator is the target speed when the clutch is disengaged.

9. The hybrid vehicle clutch control method according to claim 1, characterized in that, The clutch power engagement operation includes: Set the generator connected to the engine to speed mode, and the target speed of the generator is the target generator speed after the clutch is engaged; Obtain the current engine speed and determine the relationship between the target engine speed after clutch engagement and the current engine speed. If the target engine speed when the clutch is engaged is greater than the current engine speed, and the difference between the target engine speed when the clutch is engaged and the actual generator speed is not less than the ninth preset value, then the engine torque target is the target torque after the clutch is engaged. If the target engine speed when the clutch is engaged is less than the current engine speed, and the actual speed of the generator minus the target engine speed when the clutch is engaged is not less than the ninth preset value, the current engine power is calculated using the engine speed and torque. If the calculated current engine power is greater than the peak power of the generator connected to the engine minus the third offset, the engine target torque is controlled to be the first target torque. If the absolute value of the current engine speed minus the target engine speed when the clutch is engaged is less than the ninth preset value, control the clutch to engage; After the clutch is engaged, the generator is set to torque mode.

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