Hybrid vehicle mode switching method, device, vehicle, medium and product

Abstract

The present invention relates to the field of vehicle control technology, and discloses a hybrid vehicle mode switching method, device, vehicle, medium and product. The present invention divides the hybrid vehicle from series drive to parallel drive into two stages: before clutch engagement and clutch engagement. The different control targets of the two stages are used as variables, and the state equations are established in stages using the parameters of the power transmission system. By setting the optimization targets of the state equations in different stages and the connection constraints between the state equations, continuous optimization and solution are performed to obtain the optimal torque of the generator in the pre-clutch engagement stage and the optimal positive pressure change rate of the clutch engagement in the clutch engagement stage, thereby realizing staged control of the mode switching. Since the optimization target in the clutch engagement stage is to minimize the angular acceleration of the passive end of the clutch, the NVH performance of the transmission system of the hybrid vehicle is guaranteed to be optimal during the mode switching process, thereby improving the comfort of the entire vehicle and further improving the user experience.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a hybrid vehicle mode switching method, device, vehicle, medium and product. Background Art

[0002] Hybrid vehicles (HEVs) avoid the "range anxiety" faced by pure electric vehicles while offering superior fuel economy compared to gasoline-powered vehicles. They have become a hot topic in automotive research and development. When a HEV switches from series to parallel drive mode, the engine participates in driving the vehicle through clutch engagement. This switching process and clutch engagement control can easily cause noise, vibration, and harshness (NVH) issues in the drivetrain, impacting overall vehicle comfort. Therefore, ensuring NVH performance during HEV drive mode switching has become a pressing issue. Summary of the Invention

[0003] In view of this, the present invention provides a hybrid vehicle mode switching method, device, vehicle, medium and product to solve the problem in the related art that NVH problems are easily caused in the transmission system during the hybrid vehicle drive mode switching process, thereby affecting the comfort of the entire vehicle.

[0004] In a first aspect, the present invention provides a method for switching modes of a hybrid vehicle, the method comprising:

[0005] Obtaining powertrain parameters of a hybrid vehicle;

[0006] The hybrid vehicle switches from series drive to parallel drive in a first phase before clutch engagement and a second phase in which the clutch engages, and based on the powertrain parameters, establishes a first state equation corresponding to the first phase with the generator torque as a variable, and establishes a second state equation corresponding to the second phase with the clutch engagement positive pressure change rate as a variable;

[0007] Minimizing the time consumption in the first stage is used as an optimization objective of the first state equation, minimizing the angular acceleration of the clutch passive end in the second stage is used as an optimization objective of the second state equation, and establishing a connection constraint between the first state equation and the second state equation based on the angular velocity of the clutch active end. The first state equation and the second state equation are jointly solved to obtain the optimal torque of the generator corresponding to the first stage and the optimal positive pressure change rate of the clutch engagement corresponding to the second stage;

[0008] The process of switching the hybrid vehicle from series drive to parallel drive is controlled based on the optimal torque of the generator corresponding to the first stage and the optimal positive pressure change rate of the first clutch engagement corresponding to the second stage.

[0009] The present invention divides the switching of a hybrid vehicle from series drive to parallel drive into two stages: before clutch engagement and clutch engagement. The different control objectives of the two stages are used as variables, and the state equations are established in stages using the parameters of the power transmission system. Then, continuous optimization and solution are performed by setting the optimization objectives of the state equations in different stages and the connection constraints between the state equations, so as to obtain the optimal torque of the generator in the stage before clutch engagement and the optimal positive pressure change rate of the clutch engagement in the clutch engagement stage, thereby realizing the staged control of the hybrid vehicle from series drive to parallel drive. Since the optimization goal in the clutch engagement stage is to minimize the angular acceleration of the passive end of the clutch, the NVH performance of the transmission system of the hybrid vehicle is guaranteed to be optimal during the mode switching process, thereby improving the comfort of the entire vehicle and thus improving the user experience.

[0010] In an optional embodiment, controlling the process of switching the hybrid vehicle from series drive to parallel drive based on the optimal generator torque corresponding to the first stage and the optimal clutch engagement positive pressure change rate corresponding to the second stage includes:

[0011] When the hybrid vehicle switches from series drive to parallel drive and is in a first stage, controlling the generator based on the optimal torque of the generator corresponding to the first stage;

[0012] When the hybrid vehicle switches from series drive to parallel drive in the second stage, the clutch optimal positive pressure is determined based on the clutch engagement optimal positive pressure change rate corresponding to the second stage to control the clutch.

[0013] The present invention controls the generator according to the optimal torque of the generator obtained by optimization in the pre-clutch engagement stage, so that the angular velocity of the active end of the clutch approaches the passive end in the shortest time, thereby shortening the switching time of the entire mode and improving the user experience. The clutch is controlled according to the optimal positive pressure of the clutch obtained by optimization in the clutch engagement stage, so that the angular velocity of the passive end of the clutch is minimized during the mode switching process, thereby ensuring the NVH performance of the transmission system and improving the comfort of the entire vehicle.

[0014] In an optional implementation, the process of jointly solving the first state equation and the second state equation further includes:

[0015] Taking the engagement speed difference as a variable, a constraint of the first state equation is established with the difference between the angular velocity of the clutch active end and the angular velocity of the clutch passive end corresponding to the end of the first stage being no greater than the engagement speed difference, so as to jointly solve and obtain the target engagement speed difference.

[0016] The present invention uses the engagement speed difference as a variable and utilizes the relationship between the difference between the angular velocity of the clutch active end and the angular velocity of the clutch passive end and the engagement speed difference as a constraint condition for solving the first state equation. This can achieve automatic setting of the engagement speed difference, avoid the problem of low efficiency or poor stability of hybrid vehicle mode switching caused by unreasonable setting of the engagement speed difference due to insufficient human experience, and further improve the user experience.

[0017] In an optional embodiment, the method further includes:

[0018] Obtaining a current clutch active end angular velocity and a current clutch passive end angular velocity during a process in which the hybrid vehicle switches from series drive to parallel drive;

[0019] determining whether a difference between the current clutch active end angular velocity and the current clutch passive end angular velocity is greater than the target engagement speed difference;

[0020] When the difference between the current clutch active end angular velocity and the current clutch passive end angular velocity is greater than the target engagement speed difference, it is determined that the hybrid vehicle is in the first stage of switching from series drive to parallel drive.

[0021] The present invention uses the target engagement speed difference, obtained through continuous optimization, as a distinguishing criterion between the pre-clutch engagement phase and the clutch engagement phase, achieving precise demarcation between the pre-clutch engagement phase and the clutch engagement phase. When the difference between the angular velocities of the clutch active and passive ends is greater than the target engagement speed difference, the pre-clutch engagement phase is determined. This allows the clutch engagement phase to be quickly reached by controlling engine torque, shortening mode switching time and improving the user experience.

[0022] In an optional embodiment, the method further includes:

[0023] When the difference between the current clutch active end angular velocity and the current clutch passive end angular velocity is not greater than the target engagement speed difference, it is determined that the hybrid vehicle is in the second stage of switching from series drive to parallel drive.

[0024] The present invention determines that the clutch is in the clutch engagement stage when the difference between the angular velocity of the clutch active end and the angular velocity of the passive end is not greater than the target engagement speed difference, so as to ensure the NVH performance of the transmission system during the clutch engagement process by controlling the clutch engagement positive pressure change rate, thereby improving the comfort of the entire vehicle.

[0025] In an optional embodiment, establishing a connection constraint between the first state equation and the second state equation based on the angular velocity of the clutch active end includes:

[0026] A connection constraint is established between the first state equation and the second state equation by making the angular velocity of the clutch active end at the end of the first phase equal to the angular velocity of the clutch active end at the beginning of the second phase.

[0027] The present invention uses the equality of the angular velocity of the clutch active end at the end of the first stage and the angular velocity of the clutch active end at the beginning of the second stage as the connection constraint of the two state equations, thereby avoiding the discontinuity of the angular velocity of the clutch active end during the solution of the state equation, making the entire optimization solution consistent with the actual vehicle operation condition, and improving the practicality of the final mode switching strategy.

[0028] In an optional implementation, the process of jointly solving the first state equation and the second state equation further includes:

[0029] Establishing a constraint on the first state equation by taking the generator torque corresponding to the beginning and the end of the first stage as zero;

[0030] The constraints of the second state equation are established by the clutch engagement positive pressure change rate corresponding to zero at the beginning and end of the second stage, and the angular velocity of the clutch active end is equal to the angular velocity of the clutch passive end at the end of the second stage.

[0031] By establishing separate constraints for each state equation, the present invention further improves the consistency between the entire optimization solution and the actual vehicle operation conditions, thereby enhancing the practicality of the final mode switching strategy and the user experience.

[0032] In an optional embodiment, the first state equation corresponding to the first stage is established based on the power transmission system parameters with the generator torque as a variable, and the second state equation corresponding to the second stage is established with the clutch engagement positive pressure change rate as a variable, including:

[0033] establishing a first vehicle dynamics model corresponding to the first stage and a second vehicle dynamics model corresponding to the second stage based on the powertrain parameters;

[0034] Based on the first vehicle dynamics model, a first state equation corresponding to the first stage is established with the generator torque as a variable, and based on the second vehicle dynamics model, a second state equation corresponding to the second stage is established with the clutch engagement positive pressure change rate as a variable.

[0035] The present invention uses the powertrain system parameters to establish a vehicle dynamics model corresponding to different stages of clutch engagement, and then uses the vehicle dynamics model to establish state equations for different stages, further ensuring that the solution results of the state equations meet the vehicle dynamics requirements and ensure the practicality of the overall switching control scheme.

[0036] In a second aspect, the present invention provides a hybrid vehicle mode switching device, the device comprising:

[0037] an acquisition module, for acquiring parameters of a power transmission system of a hybrid vehicle;

[0038] a first processing module configured to divide the hybrid vehicle switching from series drive to parallel drive into a first stage before clutch engagement and a second stage when the clutch is engaged, and to establish, based on the powertrain parameters, a first state equation corresponding to the first stage using the generator torque as a variable, and to establish a second state equation corresponding to the second stage using the clutch engagement positive pressure change rate as a variable;

[0039] a second processing module, configured to use minimization of the time consumption in the first stage as an optimization objective of the first state equation, and minimization of the angular acceleration of the passive end of the clutch in the second stage as an optimization objective of the second state equation, establish a connection constraint between the first state equation and the second state equation based on the angular velocity of the active end of the clutch, and jointly solve the first state equation and the second state equation to obtain an optimal torque of the generator corresponding to the first stage and an optimal positive pressure change rate of the clutch engagement corresponding to the second stage;

[0040] The third processing module is used to control the process of switching the hybrid vehicle from series drive to parallel drive based on the optimal torque of the generator corresponding to the first stage and the optimal positive pressure change rate of the first clutch engagement corresponding to the second stage.

[0041] In a third aspect, the present invention provides a vehicle, wherein the vehicle is a hybrid vehicle, and the vehicle includes: a controller, wherein the controller includes:

[0042] The memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method described in the first aspect and any one of its optional embodiments by executing the computer instructions.

[0043] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the method provided in the first aspect or any corresponding embodiment thereof.

[0044] In a fifth aspect, the present invention provides a computer program product comprising computer instructions for causing a computer to execute the method provided in the first aspect or any corresponding embodiment thereof.

[0045] Beneficial effects of the present invention:

[0046] The present invention divides the switching of a hybrid vehicle from series drive to parallel drive into two stages: before clutch engagement and clutch engagement. The different control objectives of the two stages are used as variables, and the state equations are established in stages using the parameters of the power transmission system. Then, continuous optimization and solution are performed by setting the optimization objectives of the state equations in different stages and the connection constraints between the state equations, so as to obtain the optimal torque of the generator in the stage before clutch engagement and the optimal positive pressure change rate of the clutch engagement in the clutch engagement stage, thereby realizing the staged control of the hybrid vehicle from series drive to parallel drive. Since the optimization goal in the clutch engagement stage is to minimize the angular acceleration of the passive end of the clutch, the NVH performance of the transmission system of the hybrid vehicle is guaranteed to be optimal during the mode switching process, thereby improving the comfort of the entire vehicle and thus improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0048] Figure 1 is a flow chart of a hybrid vehicle mode switching method according to an embodiment of the present invention;

[0049] Figure 2 is a schematic diagram of a plug-in hybrid system according to an embodiment of the present invention;

[0050] Figure 3 is a flow chart of another hybrid vehicle mode switching method according to an embodiment of the present invention;

[0051] Figure 4 is a schematic diagram of the main working process of hybrid vehicle mode switching according to an embodiment of the present invention;

[0052] Figure 5 is a schematic diagram of an optimal torque of the first motor and an optimal positive pressure of the clutch according to an embodiment of the present invention;

[0053] Figure 6 2. It is a schematic diagram comparing the angular acceleration of the passive end of the clutch before and after optimizing the mode switching of a hybrid vehicle using an embodiment of the present invention;

[0054] Figure 7 is a schematic structural diagram of a hybrid vehicle mode switching device according to an embodiment of the present invention;

[0055] Figure 8 2 is a schematic structural diagram of a vehicle controller according to an embodiment of the present invention. DETAILED DESCRIPTION

[0056] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0057] In related art, when a hybrid vehicle switches from series drive mode to parallel drive mode, the primary consideration is ride comfort during the transition, without considering the NVH performance during the transition from series drive to parallel drive. It should be noted that the hybrid vehicles referred to in the embodiments of the present invention are all plug-in hybrid vehicles, i.e., a hybrid power system consisting of an engine, a generator (also known as a first motor), and a drive motor (also known as a second motor).

[0058] Based on this, an embodiment of the present invention provides a hybrid vehicle mode switching solution. For the specific process of switching from series drive to parallel drive of a plug-in hybrid vehicle, the NVH performance of the transmission system is optimized by continuously optimizing the speed regulation process before clutch engagement and the clutch engagement process in segments.

[0059] According to an embodiment of the present invention, an embodiment of a hybrid vehicle mode switching method is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0060] In this embodiment, a hybrid vehicle mode switching method is provided, which can be applied to a controller of a hybrid vehicle, such as a single chip microcomputer, an MCU, or other control chip. Figure 1 FIG. 1 is a flow chart of a hybrid vehicle mode switching method according to an embodiment of the present invention. Figure 1 As shown, the process includes the following steps:

[0061] Step S101 : Acquire parameters of a power transmission system of a hybrid vehicle.

[0062] Specifically, the power transmission system parameters refer to the hardware parameters of the power transmission system involved in the driving process of the hybrid vehicle, which can be obtained from the vehicle parameters of the hybrid vehicle. Figure 2 As shown, the power transmission system parameters include at least: the total inertia of the engine and the first motor , clutch active end inertia , clutch passive end inertia , first gear inertia and radius , the second gear inertia and radius , the inertia of the third gear and radius , the fourth gear inertia and radius , the second motor inertia , vehicle equivalent inertia , the equivalent stiffness of the first motor shaft and equivalent damping , equivalent stiffness of the first gear shaft and equivalent damping , the meshing stiffness between the first gear and the second gear and meshing damping , equivalent stiffness of the second gear shaft and equivalent damping , equivalent stiffness of the third gear shaft and equivalent damping , the meshing stiffness between the third gear and the fourth gear and meshing damping , equivalent stiffness of the fourth gear shaft and equivalent damping The present invention is only taken as an example and is not limited thereto.

[0063] In step S102, the hybrid vehicle is switched from series drive to parallel drive into a first stage before the clutch engages and a second stage when the clutch engages. Based on the power transmission system parameters, a first state equation corresponding to the first stage is established with the generator torque as a variable, and a second state equation corresponding to the second stage is established with the clutch engagement positive pressure change rate as a variable.

[0064] Specifically, a hybrid vehicle has two states in series drive mode. The first state is when the vehicle is driven by the second motor, with the engine driving the first motor to generate electricity, and the generated speed is higher than the speed of the clutch's passive end. The engine, first motor, and clutch active end are coaxially connected, so the clutch's active end speed is higher than the passive end speed. The second state is when the vehicle is driven by the second motor, while the engine is stopped, so the clutch's active end speed is lower than the passive end speed. When switching from series drive to parallel drive, regardless of the first or second state, the control principle for the switch is the same: in the pre-clutch engagement phase, the first motor controls the clutch's active end speed to approach the passive end speed. Once the clutch's speeds are close, the clutch is engaged, i.e., the clutch engagement phase. Therefore, the hybrid vehicle's switch from series drive to parallel drive can be divided into a first phase before clutch engagement and a second phase of clutch engagement. In the first phase, the generator torque (i.e., the first motor's torque) controls the clutch's active end speed, while in the second phase, the clutch's optimal positive pressure change rate controls the clutch's engagement. It should be noted that the angular velocity referred to in the embodiments of the present invention is also referred to as the speed. This is common knowledge among those skilled in the art and will not be further elaborated below.

[0065] In step S103, the optimization target of the first state equation is to minimize the time consumption in the first stage, and the optimization target of the second state equation is to minimize the angular acceleration of the passive end of the clutch in the second stage. A connection constraint is established between the first state equation and the second state equation based on the angular velocity of the active end of the clutch. The first state equation and the second state equation are jointly solved to obtain the optimal torque of the generator corresponding to the first stage and the optimal positive pressure change rate of the clutch engagement corresponding to the second stage.

[0066] Specifically, in order to shorten the time taken for hybrid vehicles to switch from series drive to parallel drive, the time taken for the clutch engagement stage is taken as the optimization target of this stage. At the same time, in order to ensure the NVH performance of the transmission system during the mode switching process, the angular acceleration of the clutch passive end is taken as the optimization target of the clutch engagement stage. The continuity of the segmented process is ensured by establishing a connection constraint between the two state equations, and the NVH performance optimization problem is converted into a state equation solving problem. Thus, by continuously optimizing and solving the state equation, automatic and precise control is achieved during the drive mode switching process to ensure the NVH performance of the transmission system.

[0067] Step S104 , controlling the process of switching the hybrid vehicle from series drive to parallel drive based on the optimal torque of the generator corresponding to the first stage and the optimal positive pressure change rate of the first clutch engagement corresponding to the second stage.

[0068] Specifically, by optimizing and solving the control parameters in the above steps, corresponding control is performed on different stages of the entire process of switching the hybrid vehicle from series drive to parallel drive.

[0069] The present invention divides the switching of a hybrid vehicle from series drive to parallel drive into two stages: before clutch engagement and clutch engagement. The different control objectives of the two stages are used as variables, and the state equations are established in stages using the parameters of the power transmission system. Then, continuous optimization and solution are performed by setting the optimization objectives of the state equations in different stages and the connection constraints between the state equations, so as to obtain the optimal torque of the generator in the stage before clutch engagement and the optimal positive pressure change rate of the clutch engagement in the clutch engagement stage, thereby realizing the staged control of the hybrid vehicle from series drive to parallel drive. Since the optimization goal in the clutch engagement stage is to minimize the angular acceleration of the passive end of the clutch, the NVH performance of the transmission system of the hybrid vehicle is guaranteed to be optimal during the mode switching process, thereby improving the comfort of the entire vehicle and thus improving the user experience.

[0070] In this embodiment, a hybrid vehicle mode switching method is provided, which can be applied to a controller of a hybrid vehicle, such as a single chip microcomputer, an MCU, or other control chip. Figure 3 FIG. 1 is a flow chart of a hybrid vehicle mode switching method according to an embodiment of the present invention. Figure 3 As shown, the process includes the following steps:

[0071] Step S301, obtain the power transmission system parameters of the hybrid vehicle. Figure 1 The description of step S101 is omitted here.

[0072] In step S302, the hybrid vehicle is switched from series drive to parallel drive into a first stage before the clutch engages and a second stage when the clutch engages. Based on the power transmission system parameters, a first state equation corresponding to the first stage is established with the generator torque as a variable, and a second state equation corresponding to the second stage is established with the clutch engagement positive pressure change rate as a variable.

[0073] Specifically, the above step S302 includes:

[0074] Step S3021 : establishing a first vehicle dynamics model corresponding to the first stage and a second vehicle dynamics model corresponding to the second stage based on the powertrain parameters.

[0075] The first vehicle dynamics model is shown in formula (1):

[0076] (1)

[0077] in, 、 、 Inertia The corresponding angular displacement, angular velocity, and angular acceleration are: and They are the generator output torque and the drive motor output torque respectively.

[0078] The second vehicle dynamics model is shown in formula (2):

[0079] (2)

[0080] in, The torque transmitted by the clutch, 、 、 They represent the clutch friction coefficient, the effective radius of the clutch pressure plate, and the positive pressure acting on the clutch plate respectively.

[0081] Step S3022: Based on the first vehicle dynamics model, a first state equation corresponding to the first stage is established with the generator torque as a variable, and based on the second vehicle dynamics model, a second state equation corresponding to the second stage is established with the clutch engagement positive pressure change rate as a variable.

[0082] Specifically, the first state equation is shown in formula (3):

[0083] (3)

[0084] Where T represents the generator torque, , , , .

[0085] The above second state equation is shown in formula (4):

[0086] (4)

[0087] in, , , , , , , , , , , , , , , , , , , , , Indicates the clutch engagement positive pressure change rate.

[0088] It should be noted that the process of optimizing and solving the above formulas (3) and (4) is an existing technology and can be implemented by using the optimization solution algorithm in the existing technology, which will not be described in detail here.

[0089] The embodiment of the present invention uses the powertrain system parameters to establish a vehicle dynamics model corresponding to different stages of clutch engagement, and then uses the vehicle dynamics model to establish state equations for different stages, further ensuring that the solution results of the state equations meet the vehicle dynamics requirements and ensuring the practicality of the overall switching control scheme.

[0090] In step S303, the optimization target of the first state equation is to minimize the time consumption in the first stage, and the optimization target of the second state equation is to minimize the angular acceleration of the passive end of the clutch in the second stage. A connection constraint is established between the first state equation and the second state equation based on the angular velocity of the active end of the clutch. The first state equation and the second state equation are jointly solved to obtain the optimal torque of the generator corresponding to the first stage and the optimal positive pressure change rate of the clutch engagement corresponding to the second stage.

[0091] Specifically, in the first stage, the time is expected to be as short as possible to reduce the time of the entire switching process. Therefore, the performance functional of this stage, that is, the optimization target of the first state equation mentioned above, is shown in formula (5):

[0092] (5)

[0093] in, is the optimization objective of the first state equation, The end time of the first phase.

[0094] During the second stage of clutch engagement, the transmission system will be subjected to transient shock, which will cause poor NVH performance during the switching process. The NVH performance of the transmission system is mostly indicated by the angular acceleration of the shaft, so in order to reduce the angular acceleration of the clutch passive end during the switching process, To construct the performance functional and optimize the optimal positive pressure change rate of the clutch engagement process , thereby controlling the NVH performance of the joining process. This performance functional, i.e., the optimization target of the second state equation mentioned above, is shown in formula (6):

[0095]

[0096] in, is the optimization objective of the second state equation, The time when the first phase ends is also the time when the second phase begins. The end time of the second phase.

[0097] Furthermore, the process of jointly solving the first state equation and the second state equation in the above step S303 also includes: using the engagement speed difference as a variable, establishing a constraint on the first state equation with the difference between the angular velocity of the clutch active end and the angular velocity of the clutch passive end corresponding to the end of the first stage being no greater than the engagement speed difference, as shown in formula (7), and obtaining the target engagement speed difference by jointly solving.

[0098] (7)

[0099] in, To engage the speed difference, The end time of the first phase, is the clutch active end angular velocity corresponding to the end of the first stage, i.e. the clutch active end inertia The corresponding angular velocity.

[0100] The embodiment of the present invention takes the engagement speed difference as a variable and utilizes the relationship between the difference between the angular velocity of the clutch active end and the angular velocity of the clutch passive end and the engagement speed difference as a constraint condition for solving the first state equation. This can achieve automatic setting of the engagement speed difference, avoid the problem of low efficiency or poor stability of hybrid vehicle mode switching caused by unreasonable setting of the engagement speed difference due to insufficient human experience, and further improve the user experience.

[0101] Furthermore, in step S303, establishing a connection constraint between the first state equation and the second state equation based on the clutch active end angular velocity includes establishing a connection constraint between the first state equation and the second state equation based on the clutch active end angular velocity at the end of the first phase being equal to the clutch active end angular velocity at the beginning of the second phase. The connection constraint is shown in formula (8).

[0102] (8)

[0103] in, is the angular velocity of the clutch active end corresponding to the end of the first stage, is the angular velocity of the passive end of the clutch corresponding to the beginning of the second stage, that is, the inertia of the passive end of the clutch The corresponding angular velocity should be noted that since the first and second phases are continuous in time, the end of the first phase and the beginning of the second phase are at the same moment. By ensuring that the clutch active end speed at the end of the first phase is the same as the speed at the beginning of the second phase, discontinuities in the two-phase optimization are avoided.

[0104] The present invention uses the equality of the angular velocity of the clutch active end at the end of the first stage and the angular velocity of the clutch active end at the beginning of the second stage as the connection constraint of the two state equations, thereby avoiding the discontinuity of the angular velocity of the clutch active end during the solution of the state equation, making the entire optimization solution consistent with the actual vehicle operation condition, and improving the practicality of the final mode switching strategy.

[0105] In addition, in practical applications, the process of jointly solving the first state equation and the second state equation in step S303 further includes:

[0106] In step a1, the constraints of the first state equation are established with the generator torque corresponding to zero at the beginning and end of the first stage. Specifically, they are shown in formulas (9) and (10).

[0107] (9)

[0108] (10)

[0109] in, represents the generator torque corresponding to the beginning of the first stage, Indicates the generator torque corresponding to the end of the first stage.

[0110] In step a2, the constraints for the second state equation are established, with the corresponding clutch engagement positive pressure change rate being zero at the beginning and end of the second phase, and the clutch active end angular velocity being equal to the clutch passive end angular velocity at the end of the second phase. Specifically, these constraints are shown in Formulas (11), (12), and (13).

[0111] (11)

[0112] (12)

[0113] (13)

[0114] in, and They represent the clutch engagement positive pressure change rate corresponding to the beginning and end of the second stage, and They represent the angular velocity of the clutch active end and the angular velocity of the clutch passive end at the end of the second stage respectively.

[0115] The embodiment of the present invention further improves the consistency of the entire optimization solution with the actual vehicle operation conditions by establishing separate constraints for each state equation, thereby improving the practicality of the final mode switching strategy and the user experience.

[0116] Step S304 , controlling the process of switching the hybrid vehicle from series drive to parallel drive based on the optimal torque of the generator corresponding to the first stage and the optimal positive pressure change rate of the first clutch engagement corresponding to the second stage.

[0117] Specifically, the above step S304 includes:

[0118] Step S3041 : When the hybrid vehicle switches from series drive to parallel drive and is in the first stage, the generator is controlled based on the optimal torque of the generator corresponding to the first stage.

[0119] Step S3042: When the hybrid vehicle switches from series drive to parallel drive and is in the second stage, the optimal positive pressure of the clutch is determined based on the clutch engagement optimal positive pressure change rate corresponding to the second stage to control the clutch.

[0120] The embodiment of the present invention controls the generator according to the optimal torque of the generator obtained by optimization solution in the pre-clutch engagement stage, so that the angular velocity of the active end of the clutch approaches the passive end in the shortest time, thereby shortening the switching time of the entire mode and improving the user experience. In addition, the clutch is controlled according to the optimal positive pressure of the clutch obtained by optimization solution in the clutch engagement stage, so that the angular velocity of the passive end of the clutch is minimized during the mode switching process, thereby ensuring the NVH performance of the transmission system and improving the comfort of the entire vehicle.

[0121] Furthermore, the embodiment of the present invention further includes the following steps:

[0122] Step b1, obtaining the current clutch active end angular velocity and the current clutch passive end angular velocity during the process of the hybrid vehicle switching from series drive to parallel drive.

[0123] Step b2: determine whether the difference between the current angular velocity of the clutch active end and the current angular velocity of the clutch passive end is greater than the target engagement speed difference.

[0124] Step b3: When the difference between the current clutch active end angular velocity and the current clutch passive end angular velocity is greater than the target engagement speed difference, it is determined that the hybrid vehicle is in the first stage of switching from series drive to parallel drive.

[0125] This embodiment of the present invention utilizes the target engagement speed difference, obtained through continuous optimization, as a distinguishing criterion between the pre-clutch engagement phase and the clutch engagement phase, achieving precise demarcation between the pre-clutch engagement phase and the clutch engagement phase. When the difference between the angular velocities of the clutch active and passive ends is greater than the target engagement speed difference, the pre-clutch engagement phase is determined. This allows the clutch engagement phase to be quickly reached by controlling engine torque, shortening mode switching time and improving the user experience.

[0126] Step b4: when the difference between the current clutch active end angular velocity and the current clutch passive end angular velocity is not greater than the target engagement speed difference, it is determined that the hybrid vehicle is in the second stage of switching from series drive to parallel drive.

[0127] In an embodiment of the present invention, when the difference between the angular velocity of the clutch active end and the angular velocity of the passive end is not greater than the target engagement speed difference, it is determined that the clutch is in the clutch engagement stage, so as to ensure the NVH performance of the transmission system during the clutch engagement process by controlling the clutch engagement positive pressure change rate, thereby improving the comfort of the entire vehicle.

[0128] For example, when the scheme provided by the embodiment of the present invention is used to control the mode switching of a hybrid vehicle, the main working process is as follows: Figure 4 As shown, it mainly includes:

[0129] S1: Collect vehicle parameters, i.e. the above-mentioned powertrain system parameters.

[0130] S2: The switching from series drive to parallel drive is divided into two stages: "before clutch engagement" and "clutch engagement", and the vehicle dynamics models of different stages are established respectively.

[0131] S3: Based on the characteristics of different stages and the vehicle dynamics model, establish the state equations of different stages and determine the optimization objectives and constraints of different stages.

[0132] S4: Add connection constraints between the two phases to avoid discontinuity when switching between the two phases.

[0133] S5: Perform segmented continuous optimization.

[0134] S6: Based on the optimization results, the motor and clutch control strategies during the drive mode switching process are changed to improve the NVH performance of the transmission system.

[0135] The above-mentioned transmission system NVH control scheme proposed in the embodiment of the present invention during the switching process from series drive to parallel drive is obtained by optimizing the optimal torque of the generator, that is, the optimal torque T of the first motor, the engagement speed difference σ, and the optimal positive pressure change rate U of the clutch engagement, as shown in FIG. Figure 5 As shown, by using the optimal torque T of the first motor to control the clutch active end speed in the "clutch engagement pre-stage" to approach the passive end, and then using the optimal positive pressure of the clutch To control the clutch engagement process in the "clutch engagement phase" so that the angular velocity of the passive end of the clutch during the switching process is minimized, thereby ensuring the NVH performance of the transmission system.

[0136] For example, the comparison results of the angular acceleration change of the clutch passive end when the hybrid vehicle switches from series drive to parallel drive by using the above step S6 and the comparison results before optimization are as follows: Figure 6 As shown by Figure 6 It can be seen that when the solution provided by the embodiment of the present invention is used to control the mode switching of a hybrid vehicle, the variation amplitude of the angular acceleration of the passive end of the clutch is significantly smaller, thereby significantly improving the NVH performance of the transmission system.

[0137] This embodiment also provides a hybrid vehicle mode switching device for implementing the aforementioned embodiments and preferred implementations. Details already described will not be repeated. As used below, the term "module" may refer to a combination of software and / or hardware that implements a predetermined function. While the devices described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and contemplated.

[0138] The embodiment of the present invention provides a hybrid vehicle mode switching device, such as Figure 7 As shown, the device includes:

[0139] An acquisition module 701 is used to acquire parameters of a power transmission system of a hybrid vehicle;

[0140] A first processing module 702 is configured to divide the switching of the hybrid vehicle from series drive to parallel drive into a first stage before clutch engagement and a second stage when the clutch is engaged, and establish a first state equation corresponding to the first stage with the generator torque as a variable based on the powertrain parameters, and establish a second state equation corresponding to the second stage with the clutch engagement positive pressure change rate as a variable;

[0141] The second processing module 703 is configured to optimize the first state equation by minimizing the time consumption in the first stage and the second state equation by minimizing the angular acceleration of the clutch passive end in the second stage, establish a connection constraint between the first state equation and the second state equation based on the angular velocity of the clutch active end, and jointly solve the first state equation and the second state equation to obtain the optimal torque of the generator corresponding to the first stage and the optimal positive pressure change rate of the clutch engagement corresponding to the second stage;

[0142] The third processing module 704 is configured to control a process of switching the hybrid vehicle from series drive to parallel drive based on the optimal torque of the generator corresponding to the first stage and the optimal positive pressure change rate of the first clutch engagement corresponding to the second stage.

[0143] In some optional implementations, the third processing module 704 includes:

[0144] a first processing unit for controlling the generator based on an optimal torque of the generator corresponding to the first stage when the hybrid vehicle switches from series drive to parallel drive in the first stage;

[0145] The second processing unit is used to determine the optimal positive pressure of the clutch to control the clutch based on the clutch engagement optimal positive pressure change rate corresponding to the second stage when the hybrid vehicle switches from series drive to parallel drive and is in the second stage.

[0146] In some optional implementations, the second processing module 703 further includes:

[0147] The third processing unit is used to establish the constraint of the first state equation with the engagement speed difference as the variable, and the difference between the angular velocity of the clutch active end and the angular velocity of the clutch passive end corresponding to the end of the first stage is not greater than the engagement speed difference, so as to jointly solve and obtain the target engagement speed difference.

[0148] In some optional embodiments, the device further comprises:

[0149] A fourth processing module is used to obtain the current clutch active end angular velocity and the current clutch passive end angular velocity during the process of the hybrid vehicle switching from series drive to parallel drive;

[0150] a fifth processing module, configured to determine whether a difference between a current clutch active end angular velocity and a current clutch passive end angular velocity is greater than a target engagement speed difference;

[0151] The sixth processing module is configured to determine that the hybrid vehicle is in the first stage of switching from series drive to parallel drive when the difference between the current angular velocity of the clutch active end and the current angular velocity of the clutch passive end is greater than the target engagement speed difference.

[0152] In some optional embodiments, the device further comprises:

[0153] The seventh processing module is used to determine that the hybrid vehicle is in the second stage of switching from series drive to parallel drive when the difference between the current angular velocity of the clutch active end and the current angular velocity of the clutch passive end is not greater than the target engagement speed difference.

[0154] In some optional embodiments, the second processing module 703 is specifically used to establish a connection constraint between the first state equation and the second state equation by making the angular velocity of the clutch active end at the end of the first stage equal to the angular velocity of the clutch active end at the beginning of the second stage.

[0155] In some optional implementations, the second processing module 703 further includes:

[0156] a fourth processing unit, configured to establish a constraint of the first state equation with the generator torque corresponding to the start of the first stage and the end of the first stage being zero;

[0157] The fifth processing unit is used to establish the constraints of the second state equation with the corresponding clutch engagement positive pressure change rate being zero at the beginning of the second stage and at the end of the second stage, and the angular velocity of the clutch active end being equal to the angular velocity of the clutch passive end at the end of the second stage.

[0158] In some optional implementations, the first processing module 702 includes:

[0159] a sixth processing unit, configured to establish a first vehicle dynamics model corresponding to the first stage and a second vehicle dynamics model corresponding to the second stage based on the powertrain parameters;

[0160] The seventh processing unit is used to establish a first state equation corresponding to the first stage based on the first vehicle dynamics model with the generator torque as the variable, and to establish a second state equation corresponding to the second stage based on the second vehicle dynamics model with the clutch engagement positive pressure change rate as the variable.

[0161] The further functional description of each of the above modules and units is the same as that of the above corresponding method embodiments and will not be repeated here.

[0162] The embodiment of the present invention further provides a vehicle, which is a hybrid vehicle and includes a controller, such as Figure 8 As shown, the controller includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. The various components utilize different buses to communicate with each other and can be installed on a common mainboard or installed in other ways as needed. The processor can process instructions executed in the computer device, including instructions stored in or on the memory to display graphical information of a GUI on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 8 A processor 10 is taken as an example.

[0163] The processor 10 may be a central processing unit, a network processor, or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit, a programmable logic device, or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic, or any combination thereof.

[0164] The memory 20 stores instructions that can be executed by at least one processor 10, so as to enable at least one processor 10 to execute the method shown in the above embodiment.

[0165] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created based on the use of a computer device for displaying a small program landing page, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0166] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0167] The controller further includes a communication interface 30 for the vehicle to communicate with other devices or a communication network.

[0168] The embodiment of the present invention also provides a computer-readable storage medium. The above-mentioned method according to the embodiment of the present invention can be implemented in hardware, firmware, or implemented as a computer code that can be recorded in a storage medium, or implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and downloaded through a network and will be stored in a local storage medium, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state drive, etc.; further, the storage medium can also include a combination of the above-mentioned types of memory. It can be understood that a computer, a processor, a microprocessor controller or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor or hardware, the method shown in the above embodiment is implemented.

[0169] A portion of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the form in which the computer program instruction exists in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc. Accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium that can be accessed by the computer.

[0170] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A hybrid vehicle mode switching method, characterized in that: The method comprises: Obtaining powertrain parameters of a hybrid vehicle; The hybrid vehicle switches from series drive to parallel drive in a first phase before clutch engagement and a second phase in which the clutch engages, and based on the powertrain parameters, establishes a first state equation corresponding to the first phase with the generator torque as a variable, and establishes a second state equation corresponding to the second phase with the clutch engagement positive pressure change rate as a variable; Minimizing the time consumption in the first stage is used as an optimization objective of the first state equation, minimizing the angular acceleration of the clutch passive end in the second stage is used as an optimization objective of the second state equation, and establishing a connection constraint between the first state equation and the second state equation based on the angular velocity of the clutch active end. The first state equation and the second state equation are jointly solved to obtain the optimal torque of the generator corresponding to the first stage and the optimal positive pressure change rate of the clutch engagement corresponding to the second stage; controlling a process of switching the hybrid vehicle from series drive to parallel drive based on the optimal torque of the generator corresponding to the first stage and the optimal positive pressure change rate of the first clutch engagement corresponding to the second stage; The establishing of a connection constraint between the first state equation and the second state equation based on the clutch active end angular velocity includes: A connection constraint is established between the first state equation and the second state equation by making the angular velocity of the clutch active end at the end of the first phase equal to the angular velocity of the clutch active end at the beginning of the second phase.

2. The method according to claim 1, characterized in that The process of controlling the hybrid vehicle to switch from series drive to parallel drive based on the optimal torque of the generator corresponding to the first stage and the optimal positive pressure change rate of the clutch engagement corresponding to the second stage includes: When the hybrid vehicle switches from series drive to parallel drive and is in a first stage, controlling the generator based on the optimal torque of the generator corresponding to the first stage; When the hybrid vehicle switches from series drive to parallel drive in the second stage, the clutch optimal positive pressure is determined based on the clutch engagement optimal positive pressure change rate corresponding to the second stage to control the clutch.

3. The method according to claim 2, characterized in that The process of jointly solving the first state equation and the second state equation further includes: Taking the engagement speed difference as a variable, a constraint of the first state equation is established with the difference between the angular velocity of the clutch active end and the angular velocity of the clutch passive end corresponding to the end of the first stage being no greater than the engagement speed difference, so as to jointly solve and obtain the target engagement speed difference.

4. The method according to claim 3, characterized in that The method further comprises: Obtaining a current clutch active end angular velocity and a current clutch passive end angular velocity during a process in which the hybrid vehicle switches from series drive to parallel drive; determining whether a difference between the current clutch active end angular velocity and the current clutch passive end angular velocity is greater than the target engagement speed difference; When the difference between the current clutch active end angular velocity and the current clutch passive end angular velocity is greater than the target engagement speed difference, it is determined that the hybrid vehicle is in the first stage of switching from series drive to parallel drive.

5. The method according to claim 4, characterized in that The method further comprises: When the difference between the current clutch active end angular velocity and the current clutch passive end angular velocity is not greater than the target engagement speed difference, it is determined that the hybrid vehicle is in the second stage of switching from series drive to parallel drive.

6. The method according to claim 1, characterized in that The process of jointly solving the first state equation and the second state equation further includes: Establishing a constraint on the first state equation by taking the generator torque corresponding to the beginning and the end of the first stage as zero; The constraints of the second state equation are established by the clutch engagement positive pressure change rate corresponding to zero at the beginning and end of the second stage, and the angular velocity of the clutch active end is equal to the angular velocity of the clutch passive end at the end of the second stage.

7. The method according to any one of claims 1 to 6, characterized in that The first state equation corresponding to the first stage is established based on the power transmission system parameters with the generator torque as a variable, and the second state equation corresponding to the second stage is established with the clutch engagement positive pressure change rate as a variable, including: establishing a first vehicle dynamics model corresponding to the first stage and a second vehicle dynamics model corresponding to the second stage based on the powertrain parameters; Based on the first vehicle dynamics model, a first state equation corresponding to the first stage is established with the generator torque as a variable, and based on the second vehicle dynamics model, a second state equation corresponding to the second stage is established with the clutch engagement positive pressure change rate as a variable.

8. A hybrid vehicle mode switching device, characterized in that: The device comprises: an acquisition module, for acquiring parameters of a power transmission system of a hybrid vehicle; a first processing module configured to divide the hybrid vehicle switching from series drive to parallel drive into a first stage before clutch engagement and a second stage when the clutch is engaged, and to establish, based on the powertrain parameters, a first state equation corresponding to the first stage using the generator torque as a variable, and to establish a second state equation corresponding to the second stage using the clutch engagement positive pressure change rate as a variable; A second processing module is configured to take the minimum time consumption of the first stage as the optimization target of the first state equation, take the minimum angular acceleration of the clutch passive end in the second stage as the optimization target of the second state equation, establish a connection constraint between the first state equation and the second state equation based on the angular velocity of the clutch active end, and jointly solve the first state equation and the second state equation to obtain the optimal torque of the generator corresponding to the first stage and the optimal positive pressure change rate of the clutch engagement corresponding to the second stage; the establishing of the connection constraint between the first state equation and the second state equation based on the angular velocity of the clutch active end includes: establishing the connection constraint between the first state equation and the second state equation based on the angular velocity of the clutch active end at the end of the first stage being equal to the angular velocity of the clutch active end at the beginning of the second stage; The third processing module is used to control the process of switching the hybrid vehicle from series drive to parallel drive based on the optimal torque of the generator corresponding to the first stage and the optimal positive pressure change rate of the first clutch engagement corresponding to the second stage.

9. A vehicle, said vehicle being a hybrid vehicle, characterized in that: The vehicle includes a controller, the controller including: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method according to any one of claims 1 to 7 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the method according to any one of claims 1 to 7.

11. A computer program product, characterized in that The method comprises computer instructions for causing a computer to execute the method according to any one of claims 1 to 7.

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