A method and system for controlling travel of a hybrid vehicle

Abstract

The application discloses a driving control method and system for a hybrid vehicle, wherein the method comprises the following steps: collecting operation parameters of the vehicle; calculating theoretical change values of motor torque and engine torque; obtaining an execution difference ratio of motor target torque and engine target torque; calculating a change coordination value of the engine torque; calculating a change coordination value of the motor torque; calculating a current task period executed target torque of the motor or the engine, which is used for judging an execution state of the control method; if the torque coordination state is judged, regulating the current motor torque or the engine torque based on the change coordination value of the motor torque or the engine torque; otherwise, updating the last task period executed target torque of the motor or the engine as the current task period executed target torque of the motor or the engine, and re-executing the control method after a preset task period. The application can solve the torque jitter problem of the hybrid vehicle when the engine and the driving motor are simultaneously controlled.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, and in particular to a driving control method and system for a hybrid vehicle. Background Technology

[0002] Hybrid electric vehicles (HEVs) are automobiles that add a drive motor to a traditional gasoline-powered vehicle for auxiliary propulsion, improving fuel economy and power. However, HEVs require simultaneous control of both the engine and drive motor for power output, which can easily lead to torque judder and poor vehicle smoothness. Therefore, avoiding torque judder and achieving coordinated control of the engine and drive motor has become a key technical problem that HEVs urgently need to solve. Based on this, this invention proposes a driving control method and system for hybrid vehicles. Summary of the Invention

[0003] The main objective of this invention is to propose a driving control method and system for hybrid vehicles, which solves the torque jitter problem that occurs when controlling both the engine and the drive motor simultaneously in hybrid vehicles.

[0004] The technical solution adopted in this invention is: a driving control method for a hybrid vehicle, comprising:

[0005] Collect vehicle operating parameters;

[0006] Based on the vehicle's operating parameters, the theoretical changes in motor torque and engine torque, the execution difference of motor target torque and engine target torque are calculated respectively, and the execution difference ratio between motor target torque and engine target torque is obtained.

[0007] The engine torque variation coordination value is calculated based on the execution difference ratio between the motor and engine torques, and the theoretical change values ​​of the motor torque and engine torque; the motor torque variation coordination value is calculated based on the engine torque variation coordination value and the execution difference ratio between the motor target torque and the engine target torque.

[0008] Calculate the target torque already executed in the current task cycle of the motor or engine based on the coordination value of the change in motor torque or engine torque;

[0009] The execution status of this control method is determined based on the target torque already achieved by the motor and engine in the current task cycle;

[0010] If the state is determined to be torque coordinated, the current motor torque or engine torque is adjusted based on the coordination value of the change in motor torque or engine torque; if the state is determined to be non-torque coordinated, the target torque executed by the motor or engine in the previous task cycle is updated to the target torque executed by the motor or engine in the current task cycle, and the control method is re-executed after a preset task cycle interval.

[0011] According to the above technical solution, the operating parameters also include: acceleration change rate limit, vehicle unloaded mass, wheel radius, vehicle transmission ratio, maximum allowable change in engine load per unit time, maximum mechanical change capability of motor torque per unit time, maximum mechanical change capability of engine torque per unit time, engine steady-state target torque, and motor steady-state target torque. Furthermore, the above parameters can be obtained based on actual measurements, calibration, or empirical values.

[0012] According to the above technical solution, the method for calculating the theoretical change value of motor torque includes:

[0013] The upper limit of the vehicle's driving torque variation is calculated based on the acceleration rate of change limit, the vehicle's unloaded mass, wheel radius, vehicle transmission ratio, and mission cycle.

[0014] The upper limit of motor torque variation is calculated based on the maximum allowable change in engine load per unit time and the maximum mechanical change capability of motor torque per unit time.

[0015] The vehicle's driving torque variation capability is calculated based on the upper limit of motor torque variation and the maximum mechanical variation capability of engine torque per unit time.

[0016] The percentage of motor torque variation is calculated based on the vehicle's driving torque variation capability and the upper limit of motor torque variation.

[0017] The theoretical change value of motor torque is calculated based on the proportion of motor torque change, the upper limit of vehicle drive torque change, the upper limit of motor torque change, and the task cycle.

[0018] According to the above technical solution, the method for calculating the theoretical change value of engine torque includes:

[0019] The percentage of engine torque change is calculated based on the maximum mechanical change capability of engine torque per unit time and the change capability of the vehicle's drive torque.

[0020] The theoretical value of engine torque change is calculated based on the percentage of engine torque change, the upper limit of the vehicle drive torque change, the maximum mechanical change capability of engine torque per unit time, and the task cycle.

[0021] According to the above technical solution, the calculation method of the upper limit of the vehicle driving torque variation includes: the upper limit of the vehicle driving torque variation is equal to the acceleration change rate limit multiplied by the vehicle's unloaded mass multiplied by the wheel radius multiplied by the mission cycle and then divided by the vehicle's transmission ratio.

[0022] The calculation method for the upper limit of motor torque variation includes: the upper limit of motor torque variation is equal to the smaller of the maximum allowable change in engine load and the maximum mechanical change capability of motor torque;

[0023] The calculation method for the vehicle's driving torque variation capability includes: the vehicle's driving torque variation capability is equal to the upper limit of the motor torque variation plus the maximum mechanical variation capability of the engine torque per unit time.

[0024] According to the above technical solution, the calculation method for the percentage of motor torque change includes: the percentage of motor torque change is equal to the upper limit of motor torque change divided by the overall vehicle driving torque change capability.

[0025] The calculation method for the theoretical change value of motor torque includes: the theoretical change value of motor torque is equal to the smaller of the value obtained by multiplying the upper limit of motor torque change by the task cycle and the value obtained by multiplying the percentage of motor torque change by the upper limit of vehicle drive torque change.

[0026] According to the above technical solution, the method for calculating the percentage of engine torque variation includes:

[0027] The percentage of engine torque variation is equal to the maximum mechanical change capability of engine torque per unit time divided by the change capability of the vehicle's driving torque.

[0028] The calculation method for the theoretical change value of engine torque includes: the theoretical change value of engine torque is equal to the smaller value between the maximum mechanical change capability of engine torque per unit time multiplied by the task cycle and the value obtained by multiplying the proportion of engine torque change by the upper limit of the change value of the whole vehicle drive torque.

[0029] According to the above technical solution, the calculation method of the target torque execution difference of the motor includes: the target torque execution difference of the motor is equal to the steady-state target torque of the motor minus the target torque already executed by the motor in the previous task cycle;

[0030] The calculation method for the target torque execution difference of the engine includes: the target torque execution difference of the engine is equal to the steady-state target torque of the engine minus the target torque already executed by the engine in the previous task cycle.

[0031] According to the above technical solution, the calculation method for the execution difference ratio of the motor torque and the engine torque includes: the execution difference ratio of the motor torque and the engine torque is equal to the absolute value of the execution difference of the motor target torque divided by the execution difference of the engine target torque.

[0032] According to the above technical solution, the calculation method of the engine torque change coordination value includes: the engine torque change coordination value is equal to the smaller value obtained by dividing the theoretical change value of the motor torque by the ratio of the execution difference between the motor torque and the engine torque and the theoretical change value of the engine torque, multiplied by the sign of the engine's target torque execution difference.

[0033] When the target torque execution difference of the engine is not less than 0, the sign of the target torque execution difference of the engine is equal to 1; when the target torque execution difference of the engine is less than 0, the sign of the target torque execution difference of the engine is equal to -1.

[0034] According to the above technical solution, the calculation method of the motor torque change coordination value includes: the motor torque change coordination value is equal to the absolute value of the engine torque change coordination value multiplied by the ratio of the execution difference between the motor and engine torques, and then multiplied by the target torque execution difference sign of the motor.

[0035] When the target torque execution difference of the motor is not less than 0, the sign of the target torque execution difference of the motor is equal to 1; when the target torque execution difference of the motor is less than 0, the sign of the target torque execution difference of the motor is equal to -1.

[0036] According to the above technical solution, the calculation method of the target torque already executed by the motor in the current task cycle includes: the target torque already executed by the motor in the current task cycle is equal to the target torque already executed by the motor in the previous task cycle plus the motor torque change coordination value;

[0037] The calculation method for the target torque already executed by the engine in the current mission cycle includes: the target torque already executed by the engine in the current mission cycle is equal to the target torque already executed by the engine in the previous mission cycle plus the engine torque change coordination value.

[0038] According to the above technical solution, the method for determining the execution status of this control method includes:

[0039] Compare the target torque already executed by the engine and the steady-state target torque of the engine in the current mission cycle, and the target torque already executed by the motor and the steady-state target torque of the motor in the current mission cycle, respectively.

[0040] If both are the same, it is judged to be a torque-coordinated state; if either is different, it is judged to be a non-torque-coordinated state.

[0041] Another aspect of the present invention provides a driving control system for a hybrid vehicle, which executes the driving control method for the hybrid vehicle described above.

[0042] The beneficial effects of this invention are: the driving control method and system for hybrid vehicles provided by this invention coordinate the difference in torque execution between the motor and the engine by setting engine torque change coordination values ​​and motor torque change coordination values, thereby enabling the engine and motor to simultaneously reach their set target torque, avoiding torque jitter and improving vehicle smoothness.

[0043] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a flowchart of a hybrid vehicle driving control method according to an embodiment of the present invention;

[0046] Figure 2 This is a step diagram of the driving control method for a hybrid vehicle according to an embodiment of the present invention. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0048] It should be noted that the illustrations provided in the embodiments of the present invention are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0049] In this invention, it should also be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used only for descriptive and distinguishing purposes and should not be construed as indicating or implying relative importance.

[0050] Example 1

[0051] This embodiment provides a driving control method for a hybrid vehicle, the process of which is as follows: Figure 1 As shown, the steps include:

[0052] S1. Collect vehicle operating parameters, including the target torque T1(k-1) already executed by the motor in the previous task cycle. motor The target torque T1(k-1) already achieved by the engine in the previous mission cycle. engine.

[0053] Specifically, the operating parameters also include: acceleration rate of change limit. Vehicle unloaded mass m, wheel radius r, vehicle transmission ratio i, maximum allowable change in engine load ΔT per unit time engineallowmax The maximum mechanical change capacity of motor torque per unit time ΔT1 motormax The maximum mechanical change capability of engine torque per unit time ΔT enginemax The steady-state target torque T of the engine engine The steady-state target torque T of the motor motor Among them, ΔT engineallowmax ΔT1 motormax ΔT enginemax These parameters can be obtained through bench testing or empirical values. All of the parameters mentioned above can be obtained based on actual measurements, calibrations, or empirical values.

[0054] S2. Calculate the theoretical change value ΔT1 of the motor torque. motor The theoretical change in engine torque ΔT1 engine The execution difference ΔT of the motor target torque motor The execution difference ΔT between the engine target torque and the target torque engine The execution difference ratio β between the target torque of the motor and the target torque of the engine is obtained. motoengine .

[0055] S201. Calculate the theoretical change in motor torque ΔT1 motor The theoretical change in engine torque ΔT1 engine .

[0056] Specifically, the theoretical change in motor torque ΔT1 is calculated. motor The process includes:

[0057] Based on the rate of change of acceleration Calculate the upper limit of the vehicle's driving torque variation ΔT based on the vehicle's unloaded mass m, wheel radius r, vehicle transmission ratio i, and mission cycle Δt. all ,

[0058]

[0059] That is, the upper limit of the change in the driving torque of the whole vehicle ΔT all Equal to the limit of the rate of change of acceleration Multiply by the vehicle's unloaded mass m, multiply by the wheel radius r, multiply by the mission cycle Δt, and then divide by the vehicle's transmission ratio i.

[0060] Based on the maximum allowable change in engine load ΔT per unit time engineallowmax The maximum mechanical change capacity of motor torque per unit time ΔT1motormax Calculate the upper limit of motor torque variation ΔT motormax ,

[0061] ΔT motormax =min(ΔT) engineallowmax , ΔT1 motormax )

[0062] That is, the upper limit of the motor torque variation ΔT motormax Equal to the maximum allowable change in engine load ΔT engineallowmax With respect to the maximum mechanical variation capability ΔT1 of motor torque motormax The smaller value.

[0063] Based on the upper limit of motor torque variation ΔT motormax The maximum mechanical change capability of engine torque per unit time ΔT enginemax Calculate the vehicle's ability to change drive torque ΔT max ,

[0064] ΔT max =ΔT motormnax +ΔT enginemax

[0065] That is, the vehicle's driving torque variation capability ΔT max Equal to the upper limit of the motor torque variation ΔT motormax Adding the maximum mechanical change capability of engine torque per unit time ΔT enginemax .

[0066] Based on the vehicle's driving torque variation capability ΔT max Upper limit of motor torque variation ΔT motormax Calculate the percentage of motor torque variation γ motormax ,

[0067]

[0068] That is, the percentage change in motor torque γ motormax Equal to the upper limit of motor torque variation ΔT motormax Divide by the vehicle's driving torque variation capability ΔT max .

[0069] Based on the proportion of motor torque change γ motormax Upper limit of vehicle drive torque variation ΔT all Upper limit of motor torque variation ΔT motormax Calculate the theoretical change value ΔT1 of motor torque during the task cycle Δt. motor ,

[0070] ΔT1 motor =min(γ) motormax *ΔT all ΔTmotormax *Δt)

[0071] That is, the theoretical change in motor torque ΔT1 motor Equal to the upper limit of motor torque variation ΔT all The value obtained by multiplying by the task period Δt and the percentage of motor torque change γ motormax Multiply by the upper limit of the change in the vehicle's driving torque ΔT all The smaller of the obtained values.

[0072] Calculate the theoretical change in engine torque ΔT1 engine The process includes:

[0073] The vehicle's driving torque variation capability ΔT is obtained from the above calculation process. max .

[0074] Based on the maximum mechanical change capability of engine torque per unit time ΔT enginemax The vehicle's driving torque variation capability ΔT max Calculate the percentage of engine torque variation γ enginemax ,

[0075]

[0076] That is, the percentage change in engine torque γ enginemax Equal to the maximum mechanical change capacity of engine torque per unit time ΔT enginemax Divide by the vehicle's driving torque variation capability ΔT max .

[0077] Based on the proportion of engine torque change γ enginemax The upper limit of the change in the vehicle's driving torque, ΔT max The maximum mechanical change capability of engine torque per unit time ΔT enginemax Calculate the theoretical change value ΔT1 of engine torque based on the task cycle Δt. engine ,

[0078] ΔT1 engine =min(γ) enginemax *ΔT all ΔT enginemax *Δt)

[0079] That is, the theoretical change in engine torque ΔT1 engine Equal to the maximum mechanical change capacity of engine torque per unit time ΔT enginemax The value obtained by multiplying by the mission period Δt is the proportion of the engine torque change γ. enginemax Multiply by the upper limit of the change in the vehicle's driving torque ΔT max The smaller of the obtained values.

[0080] S202. Calculate the execution difference ΔT of the motor target torque. motor The execution difference ΔT between the engine target torque and the target torque engine .

[0081] Specifically, the execution difference ΔT of the motor target torque is calculated. motor The process includes:

[0082] Based on the steady-state target torque T of the motor motor The target torque T1(k-1) already achieved by the motor in the previous task cycle. motor Calculate the execution difference ΔT of the target torque of the motor motor ,

[0083] ΔT motor =T motor -T1(k-1) motor

[0084] That is, the target torque execution difference ΔT of the motor motor Equal to the steady-state target torque T of the motor motor Subtract the target torque T1(k-1) already executed by the motor in the previous task cycle. motor .

[0085] Calculate the execution difference ΔT for the engine target torque engine The process includes:

[0086] Based on the engine's steady-state target torque T engine The target torque T1(k-1) already achieved by the engine in the previous mission cycle. engine Calculate the execution difference ΔT for the engine target torque engine ,

[0087] ΔT engine =T engine -T1(k-1) engine

[0088] That is, the execution difference ΔT of the engine target torque. engine Equal to the engine's steady-state target torque T engine Subtract the target torque T1(k-1) already executed by the engine in the previous mission cycle. engine .

[0089] S203. Calculate the execution difference ratio β between the target torque of the motor and the target torque of the engine. motoengine .

[0090] Specifically, based on the target torque execution difference ΔT of the motor motor The execution difference ΔT between the engine target torque and the target torque engine Calculate the execution difference ratio β between the target torque of the electric motor and the target torque of the engine. motoengine ,

[0091]

[0092] That is, the difference in execution torque between the motor and the engine is equal to the difference ΔT between the target torque of the motor and the target torque of the engine. motor Divide by the execution difference ΔT of the engine target torque engine Take the absolute value.

[0093] S3, Based on the execution difference ratio β between the target torque of the motor and the target torque of the engine. motoengine The theoretical change in motor torque ΔT1 motor The theoretical change in engine torque ΔT1 engine Calculate the engine torque variation coordination value ΔT2 engine Based on the engine torque variation coordination value ΔT2 engine The execution difference ratio β between the target torque of the electric motor and the target torque of the engine motoengine Calculate the coordinated value ΔT2 of motor torque variation motor .

[0094] Specifically, S301, calculate the engine torque variation coordination value ΔT2. engine The specific method is as follows:

[0095]

[0096] That is, the coordinated value of engine torque variation ΔT2 engine Equal to the theoretical change in motor torque ΔT1 motor Divide by the execution difference ratio β between the target torque of the electric motor and the target torque of the engine. motoengine The obtained value is compared with the theoretical change in engine torque ΔT1 engine The smaller value is then multiplied by the sign of the engine's target torque execution difference, s(ΔT). engine ).

[0097] Furthermore, the sign of the engine's target torque execution difference is denoted by s(ΔT). engine Specifically,

[0098]

[0099] That is, when the execution difference ΔT of the engine target torque engine When the difference is not less than 0, the sign of the target torque execution difference of the engine is s(ΔT). engine The target torque difference ΔT of the engine is equal to 1. engine When less than 0, the sign of the target torque execution difference of the engine is s(ΔT). engine ) equals -1.

[0100] S302, Based on the engine torque change coordination value ΔT2 obtained in step S301 engine Calculate the coordinated value ΔT2 of motor torque variation motor The specific method is as follows:

[0101] &ΔT2 motor =|ΔT2 engine |*β motoengine *s(ΔT motor )

[0102] That is, the coordinated value of motor torque variation ΔT2 motor Equal to the engine torque change coordination value ΔT2 engine The absolute value multiplied by the difference in torque between the motor and the engine, β motoengine Then multiply by the target torque of the motor, the difference in torque, denoted as s(ΔT). motor ).

[0103] Furthermore, the target torque execution difference of the motor is indicated by the symbol s(ΔT). motor Specifically,

[0104]

[0105] That is, when the target torque execution difference ΔT of the motor motor When the difference between the target torque and the actual torque of the motor is not less than 0, the sign of the difference is s(ΔT). motor The target torque difference ΔT of the motor is equal to 1. motor When less than 0, the sign of the target torque execution difference of the motor is s(ΔT). motor ) equals -1.

[0106] S4, Coordination value ΔT2 based on the change in motor torque motor The executed target torque T1(k-1) of the motor in the previous task cycle. motor Calculate the executed target torque T1(k) of the motor in the current task cycle. motor Based on the engine torque variation coordination value ΔT2 engine The executed target torque T1(k-1) of the motor in the previous task cycle. motor Calculate the executed target torque T1(k) of the engine in the current mission cycle. engine And determine the execution status of this control method.

[0107] S401. Calculate the executed target torque T1(k) of the motor in the current task cycle. motor And the executed target torque T1(k) of the engine in the current mission cycle. engine .

[0108] Specifically, calculate the executed target torque T1(k) of the motor in the current task cycle.motor The method is as follows:

[0109] T1(k) motor =T1(k-1) motor +ΔT2 motor

[0110] That is, the target torque T1(k) already executed by the motor in the current task cycle. motor This is equal to the target torque T1(k-1) already executed by the motor in the previous task cycle. motor Add the coordination value ΔT2 of the change in motor torque motor .

[0111] Calculate the executed target torque T1(k) of the engine in the current mission cycle. engine The method is as follows:

[0112] T1(k) engine =T1(k-1) engine +ΔT2 engine

[0113] That is, the target torque T1(k) already executed by the engine in the current mission cycle. engine This is equal to the target torque T1(k-1) already executed by the engine in the previous mission cycle. engine Add the engine torque variation coordination value ΔT2 engine .

[0114] S402, Executed target torque T1(k) of the engine based on the current mission cycle. engine The executed target torque T1(k) of the motor in the current task cycle. motor The steady-state target torque T of the engine engine and the steady-state target torque T of the motor motor Determine the execution status of this control method.

[0115] Specifically, if the engine's executed target torque T1(k) in the current mission cycle... engine Equal to the engine's steady-state target torque T engine Furthermore, the executed target torque T1(k) of the motor in the current task cycle. motor Equal to the steady-state target torque T of the motor motor If so, it is determined that the engine is in a torque coordination state. If the engine's executed target torque T1(k) for the current task cycle... engine Not equal to the engine's steady-state target torque T engine Or the executed target torque T1(k) of the motor in the current task cycle. motor Not equal to the steady-state target torque T of the motor motorIf the torque is not in a coordinated state, it is determined that the engine and motor are not in a torque-coordinated state. The torque-coordinated state refers to the operating state in which the engine and motor can simultaneously achieve their set target torque.

[0116] S5. If the torque is determined to be in a coordinated state, the current motor torque or engine torque is adjusted based on the coordination value of the change in motor torque or engine torque. If the torque is not determined to be in a coordinated state, the target torque executed by the motor or engine in the previous task cycle is updated to the target torque executed by the motor or engine in the current task cycle, and this control method is re-executed after a preset task cycle interval.

[0117] The purpose of this step is to verify whether the engine and motor coordinate torque, and to cycle through this control method if the engine and motor fail to coordinate torque until torque synchronization is achieved.

[0118] Example 2

[0119] This embodiment provides another method for driving control of a hybrid vehicle, the steps of which are as follows: Figure 2 As shown.

[0120] T1. Calculate the upper limit of the vehicle's driving torque variation ΔT all .

[0121] Specifically, based on the acceleration rate of change limit Calculate the upper limit of the change in the vehicle's drive torque ΔT all .

[0122] T2. Calculate the upper limit of motor torque variation ΔT motormax .

[0123] Specifically, based on the maximum allowable change in engine load ΔT per unit time. engineallowmax The maximum mechanical change capacity of motor torque per unit time ΔT1 motormax Calculate the upper limit of motor torque variation ΔT motormax .

[0124] T3. Calculate the vehicle's driving torque variation capability ΔT max .

[0125] Specifically, based on the upper limit of the motor torque variation ΔT motormax The maximum mechanical change capability of engine torque per unit time ΔT1 motormax Calculate the vehicle's ability to change drive torque ΔT max .

[0126] T4. Calculate the percentage change in motor torque γ motormax and the proportion of engine torque change γ enginemax .

[0127] Specifically, based on the vehicle's driving torque variation capability ΔT max Upper limit of motor torque variation ΔT motormax The maximum mechanical change capability of engine torque per unit time ΔT enginemax Calculate the percentage of motor torque variation γ motormax and the proportion of engine torque change γ enginemax .

[0128] T5. Calculate the theoretical change in motor torque ΔT1 motor and the theoretical change in engine torque ΔT1 engine .

[0129] Specifically, based on the proportion of motor torque change γ motormax Engine torque variation ratio γ enginemax Upper limit of vehicle drive torque variation ΔT all Upper limit of motor torque variation ΔT motormax The maximum mechanical change capability of engine torque per unit time ΔT1 motormax Calculate the theoretical change value ΔT1 of motor torque based on the task period Δt. motor and the theoretical change in engine torque ΔT1 engine .

[0130] T6. Calculate the engine's target torque execution difference ΔT engine The difference ΔT between the target torque of the motor and the actual torque. motor .

[0131] Specifically, based on the engine's steady-state target torque ΔT engine The steady-state target torque T of the motor motor The target torque T1(k-1) already achieved by the engine in the previous mission cycle. engine The target torque T1(k-1) already achieved by the motor in the previous task cycle. motor Calculate the target torque execution difference ΔT of the engine engine The difference ΔT between the target torque of the motor and the actual torque. motor .

[0132] T7. Calculate the execution difference ratio β between the motor and engine torque. motoengine .

[0133] Specifically, based on the engine's target torque execution difference ΔT engine The difference ΔT between the target torque of the motor and the actual torque. motor Calculate the execution difference ratio β between the motor and engine torques. motoengine .

[0134] T8. Calculate the engine torque variation coordination value ΔT2 engine Coordination value ΔT2 of motor torque variationmotor .

[0135] Specifically, based on the execution difference ratio β between the motor and engine torques. motoengine Theoretical change in motor torque ΔT1 motor and the theoretical change in engine torque ΔT1 engine The sign of the target torque execution difference of the engine is s(ΔT). engine The sign of the difference between the target torque of the motor and the execution torque is s(ΔT). motor Calculate the engine torque variation coordination value ΔT2 engine Coordination value ΔT2 of motor torque variation motor .

[0136] T9. Calculate the target torque T1(k-1) already executed by the engine in the current mission cycle. engine And the target torque T1(k-1) already executed by the motor in the current task cycle. motor .

[0137] Specifically, based on the target torque T1(k-1) already executed by the engine in the previous mission cycle. engine The target torque T1(k-1) already achieved by the motor in the previous task cycle. motor Engine torque variation coordination value ΔT2 engine Coordination value ΔT2 of motor torque variation motor Calculate the target torque T1(k) already executed by the engine in the current mission cycle. engine And the target torque T1(k) already executed by the motor in the current task cycle. motor .

[0138] T10, Determine the program execution status.

[0139] Specifically, based on the target torque T1(k) already executed by the engine in the current mission cycle. engine The target torque T1(k) already achieved by the motor in the current task cycle. motor The steady-state target torque ΔT of the engine engine and the steady-state target torque T of the motor motor Determine the program execution status.

[0140] If the engine has already achieved the target torque T1(k) in the current task cycle engine Equal to the engine's steady-state target torque ΔT engine Furthermore, the target torque T1(k) already executed by the motor in the current task cycle motor Equal to the steady-state target torque T of the motor motor Then the execution ends; if the engine has already executed the target torque T1(k) in the current task cycle. engine Not equal to the engine's steady-state target torque ΔTengine Or the target torque T1(k) already executed by the motor in the current task cycle. motor Not equal to the steady-state target torque T of the motor motor Then update the target torque T1(k-1) that the motor has already executed in the previous task cycle. motor The target torque T1(k) already achieved by the motor in the current task cycle. motor The target torque T1(k-1) already achieved by the engine in the previous mission cycle. engine The target torque T1(k) already executed by the engine in the current mission cycle. engine After another task cycle Δt, the process jumps to step T6 and starts executing again.

[0141] Among them, the upper limit of the change in the vehicle's driving torque ΔT all Upper limit of motor torque variation ΔT motormax Vehicle drive torque variation capability ΔT enginemax γ, the percentage of change in motor torque motormax Engine torque variation ratio γ enginemax Theoretical change in motor torque ΔT1 motor Theoretical change in engine torque ΔT1 engine The target torque execution difference ΔT of the engine engine The target torque execution difference ΔT of the motor motor The difference in torque execution between the electric motor and the engine, β motoengine Engine torque variation coordination value ΔT2 engine Motor torque variation coordination value ΔT2 motor The target torque T1(k) already achieved by the engine during the current mission cycle. engine The target torque T1(k) already achieved by the motor in the current task cycle. motor The specific calculation method is the same as in Example 1.

[0142] Example 3

[0143] This embodiment proposes a driving control system for a hybrid vehicle, which executes the driving control method for a hybrid vehicle in Embodiment 1 or Embodiment 2.

[0144] In summary, the present invention provides a driving control method and system for a hybrid vehicle, which obtains the execution difference ratio of the motor torque and the engine torque, sets the engine torque change coordination value and the motor torque change coordination value according to the execution difference ratio, and adjusts the executed target torque of the motor in the current task cycle and the executed target torque of the engine in the task cycle so that they simultaneously reach the set steady-state target torque, thereby avoiding torque jitter and improving the smoothness of the vehicle.

[0145] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0146] The sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0147] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A driving control method for a hybrid vehicle, characterized in that, include: Collect vehicle operating parameters, including the target torque achieved by the motor or engine in the previous task cycle; Based on the vehicle's operating parameters, the theoretical changes in motor torque and engine torque, the execution difference of motor target torque and engine target torque are calculated respectively, and the execution difference ratio between motor target torque and engine target torque is obtained. The engine torque variation coordination value is calculated based on the execution difference ratio between the motor target torque and the engine target torque, and the theoretical change values ​​of the motor torque and engine torque; the motor torque variation coordination value is calculated based on the engine torque variation coordination value and the execution difference ratio between the motor target torque and the engine target torque. The target torque already executed in the current task cycle of the motor or engine is calculated based on the coordination value of the change in motor torque or engine torque, which is used to determine the execution status of this control method. If the torque is determined to be in a coordinated state, the motor torque or engine torque is adjusted based on the target torque already executed by the motor or engine in the current task cycle; if the torque is determined to be in a non-coordinated state, the target torque already executed by the motor or engine in the previous task cycle is updated to the target torque already executed by the motor or engine in the current task cycle, and this control method is re-executed after a preset task cycle interval.

2. The driving control method for a hybrid vehicle according to claim 1, characterized in that, The operating parameters also include: acceleration change rate limit, vehicle unloaded mass, wheel radius, vehicle transmission ratio, maximum allowable change in engine load per unit time, maximum mechanical change capability of motor torque per unit time, maximum mechanical change capability of engine torque per unit time, engine steady-state target torque, and motor steady-state target torque.

3. The driving control method for a hybrid vehicle according to claim 2, characterized in that, The method for calculating the theoretical change in motor torque includes: The upper limit of the vehicle's driving torque variation is calculated based on the acceleration rate of change limit, the vehicle's unloaded mass, wheel radius, vehicle transmission ratio, and mission cycle. The upper limit of motor torque variation is calculated based on the maximum allowable change in engine load per unit time and the maximum mechanical change capability of motor torque per unit time. The vehicle's driving torque variation capability is calculated based on the upper limit of motor torque variation and the maximum mechanical variation capability of engine torque per unit time. The percentage of motor torque variation is calculated based on the vehicle's driving torque variation capability and the upper limit of motor torque variation. The theoretical change value of motor torque is calculated based on the proportion of motor torque change, the upper limit of vehicle drive torque change, the upper limit of motor torque change, and the task cycle.

4. The driving control method for a hybrid vehicle according to claim 3, characterized in that, The method for calculating the theoretical change in engine torque includes: The percentage of engine torque change is calculated based on the maximum mechanical change capability of engine torque per unit time and the change capability of the vehicle's drive torque. The theoretical value of engine torque change is calculated based on the percentage of engine torque change, the upper limit of the vehicle drive torque change, the maximum mechanical change capability of engine torque per unit time, and the task cycle.

5. The driving control method for a hybrid vehicle according to claim 4, characterized in that, The calculation method for the upper limit of the vehicle drive torque variation includes: the upper limit of the vehicle drive torque variation is equal to the acceleration change rate limit multiplied by the vehicle's unloaded mass multiplied by the wheel radius multiplied by the mission cycle and then divided by the vehicle's transmission ratio. The calculation method for the upper limit of motor torque variation includes: the upper limit of motor torque variation is equal to the smaller of the maximum allowable change in engine load and the maximum mechanical change capability of motor torque; The calculation method for the vehicle's driving torque variation capability includes: the vehicle's driving torque variation capability is equal to the upper limit of the motor torque variation plus the maximum mechanical variation capability of the engine torque per unit time.

6. The driving control method for a hybrid vehicle according to claim 3, characterized in that, The calculation method for the percentage of motor torque change includes: the percentage of motor torque change is equal to the upper limit of motor torque change divided by the overall vehicle driving torque change capability; The calculation method for the theoretical change value of motor torque includes: the theoretical change value of motor torque is equal to the smaller of the value obtained by multiplying the upper limit of motor torque change by the task cycle and the value obtained by multiplying the percentage of motor torque change by the upper limit of vehicle drive torque change.

7. The driving control method for a hybrid vehicle according to claim 4, characterized in that, The calculation method for the percentage of engine torque variation includes: The percentage of engine torque variation is equal to the maximum mechanical change capability of engine torque per unit time divided by the change capability of the vehicle's driving torque. The calculation method for the theoretical change value of engine torque includes: the theoretical change value of engine torque is equal to the smaller value between the maximum mechanical change capability of engine torque per unit time multiplied by the task cycle and the value obtained by multiplying the proportion of engine torque change by the upper limit of the change value of the whole vehicle drive torque.

8. The driving control method for a hybrid vehicle according to claim 2, characterized in that, The calculation method for the target torque execution difference of the motor includes: the target torque execution difference of the motor is equal to the steady-state target torque of the motor minus the target torque already executed by the motor in the previous task cycle; The calculation method for the target torque execution difference of the engine includes: the target torque execution difference of the engine is equal to the steady-state target torque of the engine minus the target torque already executed by the engine in the previous task cycle.

9. The driving control method for a hybrid vehicle according to claim 1, characterized in that, The method for calculating the execution difference ratio between the motor and engine torques includes: the execution difference ratio between the motor and engine torques is equal to the absolute value of the execution difference of the motor target torque divided by the execution difference of the engine target torque.

10. The driving control method for a hybrid vehicle according to claim 2, characterized in that, The calculation method for the engine torque variation coordination value includes: the engine torque variation coordination value is equal to the smaller of the theoretical change value of the motor torque divided by the ratio of the execution difference between the motor torque and the engine torque, and the theoretical change value of the engine torque, multiplied by the sign of the engine's target torque execution difference. When the target torque execution difference of the engine is not less than 0, the sign of the target torque execution difference of the engine is equal to 1; when the target torque execution difference of the engine is less than 0, the sign of the target torque execution difference of the engine is equal to -1.

11. The driving control method for a hybrid vehicle according to claim 2, characterized in that, The calculation method for the motor torque variation coordination value includes: the motor torque variation coordination value is equal to the absolute value of the engine torque variation coordination value multiplied by the ratio of the execution difference between the motor and engine torques, and then multiplied by the target torque execution difference of the motor. When the target torque execution difference of the motor is not less than 0, the sign of the target torque execution difference of the motor is equal to 1; when the target torque execution difference of the motor is less than 0, the sign of the target torque execution difference of the motor is equal to -1.

12. The driving control method for a hybrid vehicle according to claim 2, characterized in that, The calculation method for the target torque already executed by the motor in the current task cycle includes: the target torque already executed by the motor in the current task cycle is equal to the target torque already executed by the motor in the previous task cycle plus the motor torque change coordination value; The calculation method for the target torque already executed by the engine in the current mission cycle includes: the target torque already executed by the engine in the current mission cycle is equal to the target torque already executed by the engine in the previous mission cycle plus the engine torque change coordination value.

13. The driving control method for a hybrid vehicle according to claim 2, characterized in that, The method for determining the execution status of this control method includes: Compare the target torque already executed by the engine and the steady-state target torque of the engine in the current mission cycle, and the target torque already executed by the motor and the steady-state target torque of the motor in the current mission cycle, respectively. If both are the same, it is judged to be a torque-coordinated state; if either is different, it is judged to be a non-torque-coordinated state.

14. A driving control system for a hybrid vehicle, characterized in that, The system performs the driving control method for a hybrid vehicle as described in any one of claims 1-13.

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