Method for suppressing continuous impact during mode switching process of power-split hybrid system

Abstract

The application provides a method for suppressing continuous impact during mode switching of a power-split hybrid system, which comprises an energy management layer and an impact suppression coordination control layer. The energy management layer decides the working mode of the hybrid system according to the actual vehicle speed, the power output end demand torque and the power battery SOC state; and based on the working mode and the power output end demand torque, the target demand torque of a TM driving motor and an ISG motor in the power-split hybrid transmission is decided. The impact suppression coordination control layer adopts a motor torque redistribution control method based on power output end demand torque compensation or TM motor demand torque compensation to optimize the actual transmission torque change slope of the transmission power output end. The application can effectively reduce the vehicle continuous impact phenomenon caused by improper coordination of the power source torque during the mode switching of the power-split hybrid system, and can greatly improve the smoothness of the mode switching process.

Description

Technical Field

[0001] The present invention belongs to the technical field of hybrid vehicle dynamics control, and in particular relates to a method for suppressing continuous impacts during a mode switching process of a power-split hybrid vehicle system. Background Art

[0002] As one of the mainstream technical solutions, hybrid power systems using power-split hybrid transmissions have been industrialized and developed and applied on a large scale.

[0003] The power-split hybrid transmission uses a planetary gear set to couple the power of the engine and the drive motor, and then transmits the power to the output end through a reducer. It has a compact structure and high transmission efficiency.

[0004] However, when using the torque coordination control algorithm to control the smoothness of the mode switching process of a power-split hybrid system, it is often difficult to accurately estimate the torque at the input and output ends of the power-split hybrid transmission and the power source response varies greatly, resulting in great difficulty in coordinating the torque of each power source during the mode switching process, making the transmission system extremely prone to torque fluctuations and torque reversal (or torque zero crossing).

[0005] In addition, the power-split hybrid transmission system will inevitably produce nonlinear characteristics such as inter-tooth backlash due to manufacturing, assembly and long-term wear. When the system's torque passes through zero, it is easy to cause gear rattle and transient impact vibration.

[0006] At the same time, external excitations such as the engine's pulsating drag torque, the drive motor's torque pulsation, and the vehicle load further aggravate the internal excitation vibration of the gear pair meshing transmission, resulting in continuous transient torsional vibration of the powertrain, and in turn causing smoothness issues such as high-frequency vibration and continuous transient impact during mode switching.

[0007] Therefore, it is necessary to suppress the impact of the power split hybrid transmission mode switching process caused by torque zero crossing to improve the smoothness of vehicle driving. Summary of the Invention

[0008] The present invention aims to provide a method for suppressing continuous shock during the mode switching process of a power-split hybrid transmission system. This method suppresses the shock during the mode switching process of a power-split hybrid transmission system caused by torque zero crossing, thereby improving the smoothness of vehicle driving. The technical solution employed is as follows:

[0009] A method for suppressing continuous impact during a mode switching process of a power-split hybrid system comprises the following steps:

[0010] Step S1: Calculate the target required torque T of the TM drive motor at time kTM (k), ISG motor target required torque T IsG (k);

[0011] Step S2, obtaining a curve diagram Q of the actual torque transmitted at the power output end, specifically comprising the following steps:

[0012] Step S21: According to the target torque T TM (k), target required torque T ISG (k) and engine output torque T ENG (k), the power split hybrid control system solves and outputs the actual transmission torque T at the power output end out (k);

[0013] Step S22: According to all T out (k) a curve Q of the actual torque transmitted at the power output end showing the torque changing with time;

[0014] Step S3: dividing the torque zero-crossing region based on Q;

[0015] Among them, the torque zero crossing area is set with a positive torque zero crossing threshold and reverse torque zero-crossing threshold

[0016] Step S4: Determine T in step S21 out (k) Whether motor torque compensation is required, if so, executing step S5, which specifically includes the following steps:

[0017] Step S41: Determine T out (k) Whether it is in the torque zero-crossing region, if so, executing step S42;

[0018] Step S42: Determine T out (k) state, if it is in the rising state and T out (k+n k )<zero torque, in descending state and T out (k+n k )>zero torque, compensation is required;

[0019] Among them, the slope of change When it is in rising state; the slope of change When it is in the descending state; n k is the number of discrete sampling intervals;

[0020] Step S5: Introduce the torque compensation factor to T TM (k) and T ISG (k) Processing to obtain the target required torque T of the TM drive motor after compensation TM_dem, the compensated ISG motor target demand torque T ISG_dem ;

[0021] Step S6, the power-split hybrid control system outputs the torque to the vehicle driveline to drive the vehicle to travel based on the engine output torque at time T TM_dem , T ISG_dem and k.

[0022] Preferably, step S5 specifically comprises the following steps:

[0023] S51, solving the compensated power output end demand torque:

[0024]

[0025] wherein T out_dem - the power output end demand torque before compensation, calculated by the power-split hybrid control system according to the driver's accelerator pedal opening degree;

[0026] ε - torque compensation factor;

[0027] comp - the abbreviation of Compensation;

[0028] out - the abbreviation of Output;

[0029] dem - the abbreviation of Demand;

[0030] When the actual transmission torque at the power output end is in a descending state, ε is greater than 0;

[0031] When the actual transmission torque at the power output end is in an ascending state, ε is less than 0;

[0032] S52, solving the compensated TM drive motor target drive torque the target drive torque of the compensated ISG motor

[0033] wherein TM - the initial letter abbreviation of Traction Motor;

[0034] ISG - the initial letter abbreviation of Integrated Starter Generator;

[0035] Dr - the abbreviation of Drive;

[0036] S521, calculating the gearbox input end estimated torque T in ;

[0037]

[0038] Among them, k in - Torsional stiffness of the transmission input in a power-split hybrid control system;

[0039] b in - Transmission input damping in power-split hybrid control systems;

[0040] θ C - The planetary carrier rotation angle of the planetary coupler in a power-split hybrid control system is measured by a rotation angle sensor at the input end of the transmission; the rotation angle sensor is installed on the planetary carrier;

[0041] θ ENG -In a power-split hybrid control system, the engine angle is obtained from the crankshaft angle signal fed back by the engine controller;

[0042] in-input end; k-torque stiffness; b-damping;

[0043] θ-rotation angle; C-planet carrier of planetary coupler;

[0044] ENG-engine;

[0045] -θ ENG The first derivative of ;

[0046] -θ C The first derivative of ;

[0047] S522: The target driving torque of the TM driving motor after compensation and the target driving torque of the ISG motor after compensation are:

[0048]

[0049] Where ρ1 is the front planetary gear ratio of the planetary coupler in the power split hybrid control system;

[0050] ρ2 - rear planetary gear ratio of the planetary coupler in a power-split hybrid control system;

[0051] i dif - Final drive ratio of the transmission in a power-split hybrid control system;

[0052] dif- is the abbreviation of Differential, the final reducer in the gearbox;

[0053] i- represents the main reduction ratio;

[0054] J TM -The moment of inertia of the TM drive motor;

[0055] J ISG-The moment of inertia of the ISG motor;

[0056] θ R -Planetary coupler ring gear angle in power-split hybrid control systems;

[0057] R-planetary coupler ring gear;

[0058] -θ R The second derivative of

[0059] S53, solve the active damping torque of the TM drive motor after compensation Active damping torque of the compensated ISG motor for:

[0060]

[0061] Among them, J ENG - The engine's moment of inertia;

[0062] θ L -gearbox output angle; L-gearbox output;

[0063] θ ENG -engine crankshaft angle;

[0064] -θ ENG The second derivative of

[0065] -θ L The second derivative of

[0066] Cr- is the abbreviation for active damping that compensates the engine crankshaft Crank;

[0067] S54, obtaining the target required torque T of the TM drive motor after compensation at time k TM_dem , ISG motor target torque after compensation T ISG_dem :

[0068]

[0069] Preferably, step S5 specifically includes the following steps:

[0070] S5A. Calculate the target driving torque of the TM drive motor before compensation and the target driving torque of the ISG motor before compensation as follows:

[0071]

[0072] ISG motor target driving torque before moment compensation;

[0073] TM drive motor target drive torque before time compensation;

[0074] ρ1 - front planetary gear ratio of the planetary coupling in the power split hybrid control system;

[0075] ρ2 - rear planetary gear ratio of the planetary coupling in the power split hybrid control system;

[0076] i dif main reduction ratio of the gearbox in the power split hybrid control system;

[0077] T out_dem power output end demand torque before compensation;

[0078] T in gearbox input end estimated torque;

[0079] J TM moment of inertia of the TM drive motor;

[0080] J ISG moment of inertia of the ISG motor;

[0081] θ R planetary coupling ring gear angle in the power split hybrid control system;

[0082] R - planetary coupling ring gear;

[0083] second derivative of θ R ;

[0084] S5B, calculating compensation amount of TM drive motor target drive torque before compensation

[0085]

[0086] wherein, TM drive motor target drive torque before time compensation, calculated by the power split hybrid control system;

[0087] ε is greater than 0 when the power output end actual transmission torque is in a descending state;

[0088] ε is less than 0 when the power output end actual transmission torque is in an ascending state;

[0089] S5C, based on calculating ISG motor target drive torque compensation amount at time k Specifically,

[0090]

[0091] S5D, solve the active damping torque of the TM drive motor before compensation Active damping torque of ISG motor before compensation for:

[0092]

[0093]

[0094] Among them, J ENG - The engine's moment of inertia;

[0095] θ L -gearbox output angle; L-output end;

[0096] θ ENG -engine crankshaft angle;

[0097] -θ ENG The second derivative of

[0098] S5E, get T after compensation at time k TM_dem 、T ISG_dem ;

[0099]

[0100] in, The active damping torque of the TM drive motor at the moment;

[0101] The active damping torque of the ISG motor at the moment;

[0102] Preferably, in step S42, the change slope is:

[0103]

[0104] Among them, T out (k) is the actual torque transmitted by the power output end at time k; n k is the number of discrete sampling intervals;

[0105] T out (k+n k ) is k+n k The actual torque transmitted by the power output end at the moment.

[0106] Preferably, in step S21, T out The calculation model of (k) is:

[0107]

[0108] Among them, k out- Torsional stiffness of the power take-off end of a power-split hybrid system;

[0109] b out -Power take-off damping in power-split hybrid systems;

[0110] θ out -In a power-split hybrid system, the power output angle is measured by a power output angle sensor, which is installed at the power output end.

[0111] Compared with the prior art, the advantages of the present invention are:

[0112] 1. This shock suppression method can effectively reduce the continuous transient shock phenomenon caused by the torque fluctuation at the power output end of the transmission due to improper coordination of the power source torque during the mode switching process of the power-split hybrid system, and can significantly improve the smoothness of the vehicle's mode switching process.

[0113] 2. This method can reduce gear rattling, knocking noise and wear during mode switching, thereby increasing the service life of the power split hybrid transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0114] Figure 1 A flow chart of a method for suppressing impact of a power-split hybrid system;

[0115] Figure 2 This is a structural diagram of a power split hybrid system;

[0116] Figure 3 Schematic diagram of the torque zero-crossing region division during the mode switching process of the power-split hybrid system;

[0117] Figure 4 A flow chart for determining the zero-crossing region of torque at the power output end of a power-split hybrid transmission;

[0118] Figure 5 The flowchart of the motor torque redistribution control method based on the power output end required torque compensation;

[0119] Figure 6 Flowchart of the motor torque redistribution control method based on TM motor demand torque compensation;

[0120] Figure 7 This is the optimization effect diagram of the actual torque slope at the power output end of the power split hybrid transmission;

[0121] Figure 8 This is a diagram showing the effect of continuous transient impact suppression during the mode switching process of the power-split hybrid system. DETAILED DESCRIPTION

[0122] The following, with reference to a schematic diagram, describes in more detail the method for suppressing continuous shock during mode switching in a power-split hybrid system of the present invention. This schematic diagram illustrates a preferred embodiment of the present invention. It should be understood that those skilled in the art may modify the invention described herein while still achieving the beneficial effects of the present invention. Therefore, the following description should be understood as a general guide for those skilled in the art and not as a limitation of the present invention.

[0123] like Figures 1 to 8 A continuous shock suppression method for the mode switching process of a power-split hybrid system is proposed, based on an energy management layer and a shock suppression coordination control layer, to improve the vehicle driving smoothness during the switching process from pure electric mode to power-split hybrid mode.

[0124] "Pure electric mode" means only Figure 2 The TM drive motor in the work. Figure 2 , which is the structural diagram of the actual power split hybrid system.

[0125] "Power Split Hybrid Mode" means Figure 2 The engine, TM drive motor and ISG motor are all working.

[0126] "TM drive motor" refers to a motor that is mainly used for driving function in power-split hybrid mode; ISG motor refers to a motor that is mainly used for power generation function in power-split hybrid mode.

[0127] A method for suppressing continuous impact during a mode switching process of a power-split hybrid system comprises the following steps:

[0128] Step S1: The energy management layer calculates the target torque T of the TM drive motor at time k based on the torque required at the power output end of the transmission at time k. TM (k) and ISG motor target torque T ISG (k), which is the target required torque before compensation.

[0129] Specifically: The energy management layer determines the operating mode of the hybrid system based on the actual vehicle speed, the required torque at the power output end, and the SOC status of the power battery.

[0130] Then, based on the working mode and the required torque at the power output end, the energy management layer of the vehicle controller of the vehicle equipped with the power split hybrid system decides the target required torque T of the TM drive motor in the power split hybrid transmission. TM (k) and the target required torque T of the ISG motor ISG (k).

[0131] The power-split hybrid system includes an engine, a transmission input, a power-split hybrid transmission, a transmission power output, and a vehicle transmission system connected in sequence.

[0132] The power split hybrid transmission includes TM motor, ISG motor, brake B1, brake B2 and planetary coupler, etc. Figure 2 shown.

[0133] Step S2: Obtain a curve diagram Q of the actual torque transmitted at the power output end.

[0134] In the impact suppression coordination control layer, the target required torques of the TM drive motor and the ISG motor calculated by the energy management layer in step S1 are sent to the corresponding motor controllers.

[0135] Each motor controller controls the actual torque output by the corresponding motor. The two torques are coupled with the engine output torque through the planetary coupler to achieve power coupling, and the power output torque is transmitted to the vehicle transmission system through the power output end of the power split hybrid transmission, and the vehicle transmission system drives the wheels to move.

[0136] The actual transmission torque at the power output end of the gearbox is estimated based on the planetary coupler ring gear angle and the power output end angle, as follows:

[0137]

[0138] Planetary coupler ring gear rotation angle θ R The feedback signal θ from the gearbox input angle sensor C and ISG motor angle signal θ ISG It is calculated based on the dynamic relationship of the planetary coupler, namely:

[0139] θ ISG +ρ1·θ R =(1+ρ1)·θ C

[0140] Among them, θ ISG -The rotation angle of the ISG motor is measured by the rotation angle sensor installed inside the motor;

[0141] Step S3: Based on Q, the torque zero-crossing region and the non-torque zero-crossing region are divided.

[0142] The torque zero crossing area is respectively provided with a positive torque zero crossing threshold and reverse torque zero-crossing threshold in greater than 0, Less than 0, such as Figure 3 shown.

[0143] The torque zero-crossing region includes a positive torque region and a negative torque region.

[0144] When the actual torque T out satisfy When the conditions are met, it is determined that the actual transmitted torque at the power output end is in the positive torque area.

[0145] When the actual torque T out satisfy When the conditions are met, it is determined that the actual transmitted torque at the power output end is in the reverse torque area.

[0146] Power split hybrid transmission power output torque T out The zero-crossing region determination flow chart is as follows: Figure 4 shown.

[0147] First, the hybrid system calculates the working mode flag and the pre-calibrated zero-crossing region judgment threshold according to the energy management layer control strategy, and judges whether the system is in the pure electric to power split hybrid mode switching stage according to whether the working mode flag meets the mode switching trigger condition. If it is recognized that the hybrid system is in the mode switching process, the actual torque T at the power output end of the transmission obtained in step S2 is used. out , further determine whether it meets the zero-crossing area judgment conditions

[0148] If the condition is not met, the power output terminal required torque or TM drive motor required torque compensation in step S5 is not performed.

[0149] If the condition is met, it is determined that the gearbox power output torque T out Located in the torque zero crossing area.

[0150] In the torque zero-crossing region, when the power output end actually transmits torque T out satisfy When the conditions are met, determine the actual transmission torque T at the power output end. out Located in the positive torque area, when the power output end actually transmits torque T out satisfy When the conditions are met, determine the actual transmission torque T at the power output end. out Located in the reverse torque region.

[0151] Step S4: Determine T in step S21 out (k) Whether motor torque compensation is required, if so, proceed to step S5.

[0152] like Figure 3 As shown, the actual torque transmitted at the power output end is discretized and its change slope is obtained as:

[0153]

[0154] Actual torque transmitted at the power output end T out The rising and falling states in the torque zero-crossing area need to be judged based on their changing slope.

[0155] If the slope of change When it is greater than 0, it is determined that the actual torque transmitted by the power output end is in an increasing state; if the slope of the change When it is less than 0, it is determined that the actual transmission torque of the power output end is in a decreasing state.

[0156] When the actual torque transmitted at the power output end is in the rising state, T out (k+n k ) is less than 0 and is in the reverse torque area, then motor torque compensation is required; if T out (k+n k ) is greater than 0 and is in the positive torque area, so motor torque compensation is not required.

[0157] When the actual torque transmitted at the power output end is in a decreasing state, T out (k+n k ) is greater than 0 and is in the positive torque area, then motor torque compensation is required; if T out (k+n k ) is less than 0 and is in the reverse torque area, so motor torque compensation is not required.

[0158] Among them, k is the time (number of calculation time steps), n k is the number of discrete sampling intervals.

[0159] In the above formula for solving the slope of change, n k Small enough.

[0160] Step S5: Introduce a compensation factor to T TM (k) and T ISG (k) Processing to obtain the target required torque T of the TM drive motor after compensation TM_dem , ISG motor target torque after compensation T ISG_dem .

[0161] Motor torque compensation: Based on the two controllable variables of the power output end demand torque and the TM drive motor demand torque in the energy management layer, the power output end demand torque is determined by the driver's accelerator pedal opening signal (the accelerator pedal in the vehicle transmission system actually operated by the driver), and the TM drive motor target torque is determined by the torque distribution module (software module, belonging to the existing technology) of the power split hybrid control system. Therefore, a motor torque redistribution control method based on the power output end demand torque compensation or a motor torque redistribution control method based on the TM motor demand torque compensation can be adopted to optimize the slope of the actual transmission torque of the power output end in the zero-crossing state.

[0162] The specific motor torque compensation method is as follows:

[0163] 1. Motor torque redistribution control method based on torque compensation required at the power output end.

[0164] This method is explained using the descending state as an example. Figure 5 As shown, based on steps S3 and S4, the driver's accelerator pedal signal in the energy management layer is input to the required torque decision module to obtain the required torque at the transmission power output end, and the compensated torque is the required (actual) torque at the transmission power output end. for:

[0165]

[0166] Among them, T out_dem is the required torque at the power output before compensation, and ε is the torque compensation factor.

[0167] Based on the compensated power output torque, the required torque can be calculated according to the dynamic torque relationship of the planetary coupler and the estimated torque at the transmission input:

[0168] TM drive motor target driving torque after compensation and the target driving torque of the ISG motor after compensation Calculated by the shock suppression coordination control layer.

[0169] Among them, calculation The specific process is:

[0170]

[0171] calculate The specific process is:

[0172]

[0173] TM drive motor driving torque after compensation and compensated ISG motor drive torque The target torques of the compensated TM drive motor and the compensated ISG motor are calculated to be superimposed on the active damping torques of the two motors to suppress the torque pulsation of the engine during mode switching.

[0174]

[0175] in, To estimate the torque T at the transmission input in and the required torque at the power output after compensation The calculated active damping torque of the TM drive motor used to compensate for the engine torque pulsation is calculated by the shock suppression coordination control layer.

[0176] To estimate the torque T at the transmission input in and the required torque at the power output after compensation The calculated active damping torque of the ISG motor used to compensate for the engine torque pulsation is calculated by the shock suppression coordination control layer.

[0177] Among them, calculation The specific process is:

[0178]

[0179] calculate The specific process is:

[0180]

[0181] The target torque requirements of the compensated TM drive motor and the compensated ISG motor are sent to their respective controllers to control the actual torque output of the motors. The actual torque delivered at the power output end after compensation is calculated using the following calculation model:

[0182]

[0183] Also changes over time, according to all Draw a curve Q1 of the actual torque transmitted at the power output end showing the change of torque over time;

[0184] The slope of the actual torque transmitted at the power output end of the gearbox after compensation The solution method is the same as that in step S42, that is:

[0185]

[0186] When the actual torque transmitted by the power output end of the compensated gearbox the changing slope (rate of change over time) of the power output end actual transmitted torque meets the following optimization control constraint condition

[0187] The optimization control constraint condition in the falling state is:

[0188]

[0189] The torque compensation factor ε is greater than 0 when the power output end actual transmitted torque is in a falling state.

[0190] If the torque compensation factor ε is less than 0 when the power output end actual transmitted torque is in a rising state.

[0191] That is, the torque compensation factor ε is a constant with an absolute value greater than or equal to 0. The optimization method of grid search is used to update the torque compensation factor ε iteratively.

[0192] 2. Motor torque redistribution control method based on TM motor demand torque compensation.

[0193] The method is described below taking the falling state as an example.

[0194] As shown in Figure 6 , based on steps S3 and S4, the gearbox power output end demand torque T out_dem is obtained by inputting the driver's accelerator pedal signal in the energy management layer to the demand torque decision module, and after power source torque distribution (which belongs to the prior art), the TM drive motor target drive torque T TM and the ISG motor target drive torque T ISG before compensation are obtained:

[0195]

[0196] T in Gearbox input end estimated torque, calculation method is the same as step S521.

[0197] In this method, the same letters as in the aforementioned method (motor torque redistribution control method based on power output end demand torque compensation) also apply to this method.

[0198] Thus, the compensation amount of the TM drive motor torque can be obtained as:

[0199]

[0200] Wherein, is the TM drive motor target drive torque compensation amount, is the TM drive motor target drive torque before compensation calculated by the energy management layer in step S1, i.e. the TM drive motor target drive torque at time k.

[0201]

[0202] Based on the target driving torque compensation of TM drive motor The target driving torque compensation of the ISG motor can be calculated based on the dynamic torque relationship of the planetary coupler.

[0203] calculate The specific process is:

[0204]

[0205] The motor torque redistribution control method based on the TM motor demand torque compensation in the impact suppression coordinated control layer calculates the target demand torque of the two motors after compensation as follows:

[0206]

[0207] Among them, the active damping torque of the TM drive motor Active damping torque of ISG motor for:

[0208]

[0209] It is the target driving torque of the ISG motor before compensation calculated by the energy management layer in step S1, that is, the target driving torque of the ISG motor at time k.

[0210] It is the active damping torque of the TM drive motor calculated by the energy management layer in step S1 for compensating the engine torque pulsation, that is, the active damping torque of the TM drive motor at time k.

[0211] It is the ISG motor active damping torque calculated by the energy management layer in step S1 for compensating the engine torque pulsation, that is, the ISG motor active damping torque at time k.

[0212] The target torque requirements of the compensated TM drive motor and the compensated ISG motor are sent to their respective controllers to control the actual torque output of the motors. The actual torque delivered at the power output end after compensation is calculated using the following calculation model:

[0213]

[0214] Also changes over time, according to all Draw a curve Q2 of the actual torque transmitted at the power output end showing the change of torque over time;

[0215] The slope of the actual torque transmitted at the power output end of the gearbox after compensation The solution method is the same as that in step S42, that is:

[0216]

[0217] When the actual torque transmitted by the power output end of the compensated gearbox When the slope of change (rate of change over time) satisfies the following optimization control constraints in the descending state, the output

[0218] The optimal control constraints satisfied in the descending state are:

[0219]

[0220] The torque compensation factor ε is greater than 0 when the actual torque transmitted at the power output end is in a decreasing state;

[0221] If the torque compensation factor ε is in a rising state when the actual torque transmitted at the power output end is in a rising state, its value is less than 0.

[0222] That is, the torque compensation factor ε is a constant whose absolute value is greater than or equal to 0. The torque compensation factor ε is iteratively updated using a grid search optimization method.

[0223] The control method in the above-mentioned impact suppression coordination control layer will be triggered only during the switching process from the pure electric mode to the power split hybrid mode determined by the energy management layer.

[0224] The motor torque redistribution control method based on the power output end demand torque compensation and the motor torque redistribution control method based on the TM motor demand torque compensation can be integrated into the impact suppression coordination control layer separately or in a redundant relationship to prevent the control algorithm from failing in the controller. The optimization effect of the actual torque slope at the power output end of the power split hybrid transmission is as follows: Figure 7 As shown in FIG, the above two compensation methods can reduce the actual torque slope transmitted by the power output end of the transmission during the torque zero-crossing process.

[0225] Step S6: The power split hybrid power transmission system is based on T TM_dem 、T ISG_dem At time k, the engine outputs torque to the wheels to drive the vehicle.

[0226] That is, T calculated by the motor torque compensation method in the impact suppression coordination control layer TM_dem 、T ISG_demThe power is distributed to the motor controller corresponding to the motor, which is coupled to the engine output torque through the planetary coupler, and the power output torque is transmitted to the vehicle transmission system through the power output end of the power split hybrid transmission. The vehicle transmission system drives the wheels to drive the vehicle together. The continuous transient impact suppression effect of the power split hybrid system mode switching process is as follows: Figure 8 As shown, it can be seen that by adopting the above two compensation methods, the continuous impact degree at the output end of the transmission is reduced, thereby improving the smoothness of the mode switching process of the power split hybrid system.

[0227] The above description is merely a preferred embodiment of the present invention and does not limit the present invention in any way. Any person skilled in the art who, without departing from the scope of the present invention, makes any equivalent substitution, modification, or other changes to the technical solution and technical content disclosed in the present invention shall be deemed to be within the scope of the present invention and still fall within the scope of protection of the present invention.

Claims

1. A method for suppressing continuous impact during mode switching of a power-split hybrid system, characterized in that: The following steps are involved: Step S1: Calculate the target required torque T of the TM drive motor at time k TM (k), ISG motor target required torque T ISG (k); Step S2, obtaining a curve diagram Q of the actual torque transmitted at the power output end, specifically comprising the following steps: Step S21: According to the target torque T TM (k), target required torque T ISG (k) and engine output torque T ENG (k), the power split hybrid control system solves and outputs the actual transmission torque T at the power output end out (k); Step S22: According to all T out (k) a curve Q of the actual torque transmitted at the power output end showing the torque changing with time; Step S3: dividing the torque zero-crossing region based on the actual torque transmission curve Q of the power output end; Among them, the torque zero crossing area is set with a positive torque zero crossing threshold and reverse torque zero-crossing threshold Step S4: Determine T in step S21 out (k) Whether motor torque compensation is required, if so, executing step S5, which specifically includes the following steps: Step S41: Determine T out (k) Whether it is in the torque zero-crossing region, if so, executing step S42; Step S42: Determine T out (k) state, if it is in the rising state and T out (k+n k )<zero torque, in descending state and T out (k+n k )>zero torque, compensation is required; Among them, the slope of change When it is in rising state; the slope of change When it is in the descending state; n k is the number of discrete sampling intervals; Step S5: Introduce the torque compensation factor to T TM (k) and T ISG (k) Processing to obtain the target required torque T of the TM drive motor after compensation TM_dem , ISG motor target torque after compensation T ISG_dem ; Step S6: The power split hybrid control system is based on T TM_dem 、T ISG_dem and the engine output torque T at time k ENG (k) outputting torque to the vehicle transmission system to drive the vehicle; Step S5 specifically includes the following steps: S51. Calculate the required torque at the power output end after compensation: Among them, T out_dem -Required torque at the power output before compensation; ε-torque compensation factor; comp-abbreviation of Compensation; out-output; dem-abbreviation for demand; When the actual transmitted torque at the power output end is in a decreasing state, ε is greater than 0; When the actual transmitted torque at the power output end is in an increasing state, ε is less than 0; S52, solving the target driving torque of the TM driving motor after compensation Target driving torque of the ISG motor after compensation Among them, TM-the abbreviation of Traction Motor; ISG-The acronym for Integrated Starter Generator; Dr- is the abbreviation of Drive; S521, calculating the estimated torque T at the transmission input end in ; Among them, k in - Torsional stiffness of the transmission input in a power-split hybrid control system; b in - Transmission input damping in power-split hybrid control systems; θ C - The planetary carrier rotation angle of the planetary coupler in a power-split hybrid control system is measured by a rotation angle sensor at the input end of the transmission; the rotation angle sensor is installed on the planetary carrier; θ ENG -In a power-split hybrid control system, the engine angle is obtained from the crankshaft angle signal fed back by the engine controller; in-input end; k-torque stiffness; b-damping; θ-rotation angle; C-planet carrier of planetary coupler; ENG-engine; The first derivative of ; The first derivative of ; S522: The target driving torque of the TM driving motor after compensation and the target driving torque of the ISG motor after compensation are: Where ρ1 is the front planetary gear ratio of the planetary coupler in the power split hybrid control system; ρ2 - rear planetary gear ratio of the planetary coupler in a power-split hybrid control system; i dif - Final drive ratio of the transmission in a power-split hybrid control system; dif- is the abbreviation of Differential, the final reducer in the gearbox; i- represents the main reduction ratio; J TM -The moment of inertia of the TM drive motor; J ISG -The moment of inertia of the ISG motor; θ R -Planetary coupler ring gear angle in power-split hybrid control systems; R-planetary coupler ring gear; The second derivative of S53, solve the active damping torque of the TM drive motor after compensation Active damping torque of the compensated ISG motor for: Among them, J ENG - The engine's moment of inertia; θ L -gearbox output angle; L-gearbox output; θ ENG -engine crankshaft angle; The second derivative of The second derivative of Cr- is the abbreviation for active damping that compensates the engine crankshaft Crank; S54, obtaining the target required torque T of the TM drive motor after compensation at time k TM_dem , ISG motor target torque after compensation T ISG_dem :

2. A method for suppressing continuous impact during mode switching of a power-split hybrid system, characterized in that: The following steps are included: Step S1: Calculate the target required torque T of the TM drive motor at time k TM (k), ISG motor target required torque T ISG (k); Step S2, obtaining a curve diagram Q of the actual torque transmitted at the power output end, specifically comprising the following steps: Step S21: According to the target torque T TM (k), target required torque T ISG (k) and engine output torque T ENG (k), the power split hybrid control system solves and outputs the actual transmission torque T at the power output end out (k); Step S22: According to all T out (k) a curve Q of the actual torque transmitted at the power output end showing the torque changing with time; Step S3: dividing the torque zero-crossing region based on the actual torque transmission curve Q of the power output end; Among them, the torque zero crossing area is set with a positive torque zero crossing threshold and reverse torque zero-crossing threshold Step S4: Determine T in step S21 out (k) Whether motor torque compensation is required, if so, executing step S5, which specifically includes the following steps: Step S41: Determine T out (k) Whether it is in the torque zero-crossing region, if so, executing step S42; Step S42: Determine T out (k) state, if it is in the rising state and T out (k+n k )<zero torque, in descending state and T out (k+n k )>zero torque, compensation is required; Among them, the slope of change When it is in rising state; the slope of change When it is in the descending state; n k is the number of discrete sampling intervals; Step S5: Introduce the torque compensation factor to T TM (k) and T ISG (k) Processing to obtain the target required torque T of the TM drive motor after compensation TM_dem , ISG motor target torque after compensation T ISG_dem ; Step S6: The power split hybrid control system is based on T TM_dem 、T ISG_dem and the engine output torque T at time k ENG (k) outputting torque to the vehicle transmission system to drive the vehicle; Step S5 specifically includes the following steps: S5A. Calculate the target driving torque of the TM drive motor before compensation and the target driving torque of the ISG motor before compensation as follows: ISG motor target driving torque before moment compensation; TM drive motor target driving torque before time compensation; ρ1 - front planetary gear ratio of the planetary coupler in the power-split hybrid control system; ρ2 - rear planetary gear ratio of the planetary coupler in a power-split hybrid control system; i dif - Final drive ratio of the transmission in a power-split hybrid control system; T out_dem -Required torque at the power output before compensation; T in -Estimated torque at the transmission input; J TM -The moment of inertia of the TM drive motor; J ISG -The moment of inertia of the ISG motor; θ R -Planetary coupler ring gear angle in power-split hybrid control systems; R-planetary coupler ring gear; The second derivative of S5B, calculate the compensation amount of the target driving torque of the TM drive motor before compensation in, TM drive motor target driving torque before time compensation; When the actual transmitted torque at the power output end is in a decreasing state, ε is greater than 0; When the actual transmitted torque at the power output end is in an increasing state, ε is less than 0; ε-torque compensation factor; S5C, based on Calculate the target driving torque compensation of the ISG motor at time k Specifically: S5D, solve the active damping torque of the TM drive motor before compensation Active damping torque of ISG motor before compensation for: Among them, J ENG - The engine's moment of inertia; θ L -gearbox output angle; L-output end; θ ENG -engine crankshaft angle; The second derivative of S5E, get T after compensation at time k TM_dem 、T ISG_dem ; 3. The method for suppressing continuous impact during mode switching of a power-split hybrid system according to claim 1 or 2, characterized in that: In step S42, the change slope is: Among them, T out (k) is the actual torque transmitted by the power output end at time k; n k is the number of discrete sampling intervals; T out (k+n k ) is k+n k The actual torque transmitted by the power output end at the moment.

4. The method for suppressing continuous impact during mode switching of a power-split hybrid system according to claim 1 or 2, characterized in that: In step S21, T out The calculation model of (k) is: Among them, k out - Torsional stiffness of the power take-off end of a power-split hybrid system; b out -Power take-off damping in power-split hybrid systems; θ out -In a power-split hybrid system, the power output angle is measured by a power output angle sensor, which is installed at the power output end.

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