Control method and device of hybrid electric vehicle and hybrid electric vehicle with control method and device

Abstract

The invention relates to the technical field of hybrid electric vehicle control, in particular to a hybrid electric vehicle control method and device and a hybrid electric vehicle with the hybrid electric vehicle. The method comprises the steps that a first operation working condition line with the highest efficiency of an engine is determined according to the characteristics of the engine; determining a second operation condition line of direct-drive steady-speed running of the engine according to the resistance line; the charging and discharging power of the power battery is determined according to the charging and discharging efficiency of the power battery and the battery temperature rise condition; determining a third operation condition line directly driven by the engine according to the first operation condition line, the second operation condition line and the charging and discharging power; and determining the required torque of the driving motor according to the third operation condition line and the required torque of the whole vehicle. Therefore, the problems that in the related technology, only the engine and the power battery are controlled to achieve the corresponding effect, collaborative optimization cannot be carried out according to the characteristics of the engine and the power battery to improve the economical efficiency, the drivability and the durability of the whole vehicle, and therefore all the performances of the whole vehicle are balanced are solved.

Description

Technical Field

[0001] The present application relates to the technical field of hybrid vehicle control, and in particular to a control method and device for a hybrid vehicle and a hybrid vehicle having the same. Background Art

[0002] Hybrid vehicles have two power sources: engine and power motor. One is driven by electric energy and motor; the other is driven by fuel and engine. Electric energy and motor drive have high energy conversion efficiency and fast power response speed, but less energy reserve; fuel and engine drive have low energy conversion efficiency and slow power response, but more energy reserve. When electric energy and fuel energy are converted to each other, there is energy loss on the one hand, and heat is generated on the other hand, which affects the reliability of the hybrid system. Therefore, how to reasonably use the engine and power battery to achieve a balance in the performance of hybrid vehicles has always been the focus and difficulty of hybrid vehicle research.

[0003] In the relevant technologies, the control of the engine is mainly focused on the engine starting process and the engine speed control, with the aim of improving the engine starting reliability and speed safety; the management of hybrid energy is mainly focused on the reasonable planning of the power battery SOC (State of Charge) and the power distribution of the power system, and also involves the specific power distribution of the engine, with the aim of improving the economy of the entire vehicle.

[0004] In summary, the relevant technology only controls the engine and the power battery separately to achieve the corresponding effects, but cannot synergistically optimize the characteristics of the engine and the power battery to improve the economy, drivability and durability of the whole vehicle, thereby achieving the purpose of balancing the performance of the whole vehicle, which urgently needs to be improved. Summary of the invention

[0005] The present application provides a control method and device for a hybrid vehicle and a hybrid vehicle having the same, so as to solve the problem in the related art that only the engine and the power battery are controlled separately to achieve the corresponding effects, but the engine and the power battery characteristics cannot be coordinated and optimized to improve the economy, drivability and durability of the whole vehicle, so as to achieve a balance in the performance of the whole vehicle.

[0006] A first aspect of the present application provides a control method for a hybrid vehicle, comprising the following steps: determining a first operating condition line in which the engine has the highest efficiency according to the characteristics of the hybrid vehicle's engine; determining a second operating condition line in which the engine is directly driven and travels at a steady speed according to the resistance line of the hybrid vehicle; determining the charge and discharge power of the power battery according to the charge and discharge efficiency of the power battery and the temperature rise of the battery; determining a third operating condition line in which the engine is directly driven according to the first operating condition line, the second operating condition line and the charge and discharge power; and determining the required torque of the drive motor according to the third operating condition line and the required torque of the entire vehicle of the hybrid vehicle.

[0007] Through the above technical scheme, the embodiment of the present application can ensure that the engine works in the most efficient state by determining the first operating condition line with the highest engine efficiency, reduce unnecessary energy loss, and improve energy utilization efficiency; in combination with the resistance line of the hybrid vehicle, determine the second operating condition line of direct drive steady speed driving, so that the output of the engine is more matched with the actual driving demand of the vehicle, avoid excessive output or insufficient output, and further improve energy efficiency; consider the charging and discharging efficiency of the power battery and the temperature rise of the battery to determine the charging and discharging power, which not only extends the service life of the battery, but also ensures that the battery works within a safe temperature range, avoiding safety hazards caused by battery overheating; through comprehensive analysis of the engine, power battery and vehicle requirements, determine the third operating condition line of engine direct drive, achieve efficient coordination between the various components of the power system, and improve the working efficiency of the overall system; dynamically adjust the required torque of the drive motor based on the required torque of the vehicle, so that the vehicle can quickly respond to the driver's operation, provide a smooth driving experience, and at the same time ensure the stability and reliability of the power system.

[0008] Optionally, in one embodiment of the present application, the first operating condition line with the highest efficiency of the engine is determined according to the characteristics of the engine of the hybrid vehicle, including: calculating the corresponding engine speed and engine torque based on the output torque of any wheel end at the target vehicle speed; determining the thermal efficiency of the engine according to the engine speed and the engine torque, and replacing the output torque to calculate the engine specific fuel consumption of the engine, and determining the engine torque corresponding to the high engine thermal efficiency as the optimal engine torque at the engine speed corresponding to the target vehicle speed, and replacing the target vehicle speed until a preset iteration stop condition is reached to generate the first operating condition line.

[0009] Through the above technical scheme, the embodiment of the present application can ensure that the engine is always in the area of ​​highest thermal efficiency by calculating the optimal torque and speed of the engine at different vehicle speeds, thereby improving fuel economy. It can also obtain the first operating condition line with the highest efficiency of the engine through iterative calculation, and comprehensively consider the efficiency and speed ratio of the engine direct drive, not only limited to the engine itself, but also more comprehensive in dimensions, thereby improving the accuracy of determining the first operating condition line.

[0010] Optionally, in one embodiment of the present application, determining the second operating condition line of the engine direct-drive steady-speed driving according to the resistance line of the hybrid vehicle includes: determining the wheel-end resistance of the hybrid vehicle according to the resistance line; calculating the corresponding engine torque according to the wheel-end resistance to generate the second operating condition line.

[0011] Through the above technical solution, the embodiment of the present application can ensure that the engine output is accurately matched with the actual demand by directly linking the wheel-end resistance with the engine torque, avoid energy waste, ensure that in the direct drive mode, the engine operates in a condition that matches the vehicle resistance, and improve the stability and economy of direct drive driving.

[0012] Optionally, in one embodiment of the present application, determining the charge and discharge power of the power battery based on the charge and discharge efficiency and battery temperature rise of the power battery includes: calculating the battery discharge power of the power battery of the hybrid vehicle under pure electric driving conditions; and determining the charging power of the power battery based on the battery discharge power.

[0013] Through the above technical scheme, the embodiment of the present application can calculate the battery discharge power under pure electric driving conditions and determine the charging power accordingly, thereby realizing refined management of the charging and discharging process of the power battery, ensuring that the battery operates within a safe and efficient range. Based on considerations of charging and discharging efficiency, the scheme ensures minimal loss during the energy conversion process and improves overall energy utilization efficiency.

[0014] Optionally, in one embodiment of the present application, determining the third operating condition line of the engine direct drive based on the first operating condition line, the second operating condition line and the charge and discharge power includes: converting the charge and discharge power into a first engine charging torque; converting the first operating condition line and the second operating condition line into a second engine charging torque; determining the third operating condition line based on the first engine charging torque and the second engine charging torque.

[0015] Through the above technical solution, the embodiment of the present application can combine the charging and discharging requirements of the power battery with the operating condition line of the engine, realize efficient coordination of energy among different components, ensure maximization of the overall energy utilization of the system, and improve the overall energy utilization efficiency.

[0016] A second aspect of the present application provides a control device for a hybrid vehicle, comprising: a first acquisition module, for determining a first operating condition line with the highest efficiency of the engine according to the characteristics of the engine of the hybrid vehicle; a second acquisition module, for determining a second operating condition line of the engine driving at a steady speed directly according to the resistance line of the hybrid vehicle; a third acquisition module, for determining the charging and discharging power of the power battery according to the charging and discharging efficiency and the temperature rise of the power battery; a fourth acquisition module, for determining a third operating condition line of direct drive of the engine according to the first operating condition line, the second operating condition line and the charging and discharging power; a control module, for determining the required torque of the drive motor according to the third operating condition line and the required torque of the whole vehicle of the hybrid vehicle.

[0017] Through the above technical scheme, the embodiment of the present application can ensure that the engine works in the most efficient state by determining the first operating condition line with the highest engine efficiency, reduce unnecessary energy loss, and improve energy utilization efficiency; in combination with the resistance line of the hybrid vehicle, determine the second operating condition line of direct drive steady speed driving, so that the output of the engine is more matched with the actual driving demand of the vehicle, avoid excessive output or insufficient output, and further improve energy efficiency; consider the charging and discharging efficiency of the power battery and the temperature rise of the battery to determine the charging and discharging power, which not only extends the service life of the battery, but also ensures that the battery works within a safe temperature range, avoiding safety hazards caused by battery overheating; through comprehensive analysis of the engine, power battery and vehicle requirements, determine the third operating condition line of engine direct drive, achieve efficient coordination between the various components of the power system, and improve the working efficiency of the overall system; dynamically adjust the required torque of the drive motor based on the required torque of the vehicle, so that the vehicle can quickly respond to the driver's operation, provide a smooth driving experience, and at the same time ensure the stability and reliability of the power system. Optionally, in one embodiment of the present application, the first acquisition module includes: a first calculation unit, used to calculate the corresponding engine speed and engine torque based on the output torque of any wheel end at the target vehicle speed; a second calculation unit, used to determine the thermal efficiency of the engine according to the engine speed and the engine torque, and replace the output torque to calculate the engine specific fuel consumption of the engine, and determine the engine torque corresponding to the high engine thermal efficiency as the optimal engine torque at the engine speed corresponding to the target vehicle speed, and replace the target vehicle speed until the preset iteration stop condition is reached to generate the first operating condition line.

[0018] Through the above technical scheme, the embodiment of the present application can ensure that the engine is always in the area of ​​highest thermal efficiency by calculating the optimal torque and speed of the engine at different vehicle speeds, thereby improving fuel economy. It can also obtain the first operating condition line with the highest efficiency of the engine through iterative calculation, and comprehensively consider the efficiency and speed ratio of the engine direct drive, not only limited to the engine itself, but also more comprehensive in dimensions, thereby improving the accuracy of determining the first operating condition line.

[0019] Optionally, in one embodiment of the present application, the second acquisition module includes: a third calculation unit, used to determine the wheel end resistance of the hybrid vehicle according to the resistance line; and a fourth calculation unit, used to calculate the corresponding engine torque according to the wheel end resistance to generate the second operating condition line.

[0020] Through the above technical solution, the embodiment of the present application can ensure that the engine output is accurately matched with the actual demand by directly linking the wheel-end resistance with the engine torque, avoid energy waste, ensure that in the direct drive mode, the engine operates in a condition that matches the vehicle resistance, and improve the stability and economy of direct drive driving.

[0021] Optionally, in one embodiment of the present application, the third acquisition module includes: a fifth calculation unit, used to calculate the battery discharge power of the power battery of the hybrid vehicle under pure electric driving conditions; and a matching unit, used to determine the charging power of the power battery based on the battery discharge power.

[0022] Through the above technical solution, the embodiment of the present application can calculate the battery discharge power under pure electric driving conditions and determine the charging power accordingly, thereby achieving refined management of the charging and discharging process of the power battery and ensuring that the battery operates within a safe and efficient range. Based on considerations of charging and discharging efficiency, the solution ensures minimal losses during the energy conversion process and improves overall energy utilization efficiency.

[0023] Optionally, in one embodiment of the present application, the fourth acquisition module includes: a first conversion unit, used to convert the charging and discharging power into a first engine charging torque; a second conversion unit, used to convert the first operating condition line and the second operating condition line into a second engine charging torque; a generation unit, used to determine the third operating condition line based on the first engine charging torque and the second engine charging torque.

[0024] Through the above technical solution, the embodiment of the present application can combine the charging and discharging requirements of the power battery with the operating condition line of the engine, realize efficient coordination of energy among different components, ensure maximization of the overall energy utilization of the system, and improve the overall energy utilization efficiency.

[0025] A third aspect of the present application provides a hybrid vehicle, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the control method of the hybrid vehicle as described in the above embodiment.

[0026] A fourth aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, which, when executed by a processor, implements the above-mentioned control method for a hybrid vehicle.

[0027] A fifth aspect of the present application provides a computer program product, including a computer program, which, when executed, is used to implement the above hybrid vehicle control method.

[0028] The embodiments of the present application can accurately determine and optimize the operating conditions of the engine and drive motor and the charging and discharging power of the power battery by analyzing and integrating the relevant parameters of the key components of the hybrid vehicle, and determine the first operating condition line with the highest efficiency of the engine, the second operating condition line of the engine direct drive at a steady speed, and the third operating condition line of the engine direct drive in turn based on multi-dimensional data such as engine characteristics, vehicle resistance line, power battery status, and vehicle required torque, and finally derive the required torque of the drive motor, fully considering the actual conditions of the key parts of the hybrid vehicle, achieving efficient and coordinated operation of the system, improving energy utilization efficiency, enhancing the power performance and driving stability of the vehicle, and at the same time effectively extending the service life of the power battery and reducing energy consumption, thereby improving the economy of the vehicle.

[0029] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0031] Figure 1 A schematic diagram of the structure of a hybrid vehicle power system of a dual-motor P13 hybrid configuration according to an embodiment of the present application;

[0032] Figure 2 A schematic diagram of the structure of a P2 hybrid electric vehicle power system according to an embodiment of the present application;

[0033] Figure 3 A flow chart of a control method for a hybrid vehicle provided according to an embodiment of the present application;

[0034] Figure 4is a schematic diagram of an optimal engine torque at an engine speed corresponding to a selected vehicle speed according to an embodiment of the present application;

[0035] Figure 5 A schematic diagram of a first operating condition line with the highest efficiency of an engine according to an embodiment of the present application;

[0036] Figure 6 A schematic diagram of a second operating condition line of an engine directly driven at a steady speed according to an embodiment of the present application;

[0037] Figure 7 It is a schematic diagram of a third operating condition line of a direct-drive engine according to an embodiment of the present application;

[0038] Figure 8 is a torque schematic diagram of a driving motor according to an embodiment of the present application;

[0039] Fig. 9 A flow chart of a control method for a hybrid vehicle according to an embodiment of the present application;

[0040] Fig.10 A schematic diagram of the structure of a control device for a hybrid vehicle provided according to an embodiment of the present application;

[0041] Fig.11 It is a schematic diagram of the structure of a vehicle provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0042] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0043] The following describes the control method and device of the hybrid vehicle of the embodiment of the present application with reference to the accompanying drawings. In view of the above-mentioned related technologies mentioned in the background technology center, only the engine and the power battery are controlled separately to achieve the corresponding effect, but the engine and the power battery characteristics cannot be coordinated and optimized to improve the economy, drivability and durability of the whole vehicle, so as to achieve a balance of the performance of the whole vehicle. The present application provides a control method of a hybrid vehicle, in which the embodiment of the present application can accurately determine and optimize the operating conditions of the engine and the drive motor and the charging and discharging power of the power battery by analyzing and integrating the relevant parameters of each key component of the hybrid vehicle, and according to the multi-dimensional data such as the engine characteristics, the vehicle resistance line, the power battery state and the required torque of the whole vehicle, the first operating condition line with the highest efficiency of the engine, the second operating condition line of the engine direct drive steady speed driving, and the third operating condition line of the engine direct drive are determined in sequence, and the required torque of the drive motor is finally obtained, which fully considers the actual situation of each key part of the hybrid vehicle, realizes the efficient coordinated operation of the system, improves the energy utilization efficiency, enhances the power performance and driving stability of the whole vehicle, and can effectively extend the service life of the power battery and reduce energy consumption, and improve the economy of the whole vehicle. This solves the problem in related technologies that only the engine and power battery are controlled separately to achieve corresponding effects, but the engine and power battery characteristics cannot be coordinated and optimized to improve the economy, drivability and durability of the whole vehicle, thereby achieving a balance in the performance of the whole vehicle.

[0044] Before explaining the control method of the hybrid vehicle according to the embodiment of the present application, the application scope of the embodiment of the present application is first explained.

[0045] The embodiment of the present application is applicable to a hybrid vehicle with an engine direct drive mode (i.e., the engine can directly participate in the drive). It includes but is not limited to a dual-motor P13 hybrid configuration and a P2 hybrid configuration. Figure 1 As shown, its structure includes: a transmission shaft 1, a coupler 2, an engine 3, a generator 4, an electric motor 5, a power battery 6, a differential 7, an inverter 8, and a separation clutch 9.

[0046] Specifically, "P13" refers to the position and function of the two motors. Generally speaking, in this configuration, the motor in the P1 position is connected to the internal combustion engine and is usually used to start the engine and recover braking energy, while the motor in the P3 position is directly connected to the transmission and is mainly responsible for providing driving torque. This configuration allows the vehicle to switch flexibly between different driving modes to achieve efficient energy management and power output.

[0047] P2 hybrid configuration Figure 2As shown, its structure includes: engine 1, separation clutch 2, motor 3, transmission 4. Generally speaking, in the P2 configuration, the motor is located between the engine and the transmission, and is separated from the engine by the clutch, so that various modes of pure electric drive, internal combustion engine drive and hybrid drive can be realized.

[0048] Specifically, Figure 3 A flow chart of a control method for a hybrid vehicle provided in an embodiment of the present application.

[0049] like Figure 3 As shown, the control method of the hybrid vehicle includes the following steps:

[0050] In step S301, a first operating condition line with the highest efficiency of the engine is determined according to the characteristics of the engine of the hybrid vehicle.

[0051] It is understandable that the engine characteristics of a hybrid vehicle include but are not limited to the changes in thermal efficiency of the engine at different speeds, the relationship between engine torque and speed, the emission level and fuel consumption of the engine under different operating conditions, etc.

[0052] Optionally, in one embodiment of the present application, a first operating condition line with the highest engine efficiency is determined based on the characteristics of the engine of a hybrid vehicle, including: calculating the corresponding engine speed and engine torque based on the output torque of any wheel end at the target vehicle speed; determining the thermal efficiency of the engine based on the engine speed and the engine torque, and changing the output torque to calculate the engine specific fuel consumption of the engine, and determining the engine torque corresponding to the high thermal efficiency of the engine as the optimal engine torque at the engine speed corresponding to the target vehicle speed, and changing the target vehicle speed until a preset iteration stop condition is reached to generate the first operating condition line.

[0053] In the actual implementation process, a certain vehicle speed is selected as the target speed (hereinafter referred to as the selected speed), and the output torque of any wheel end is selected. The corresponding engine speed and torque are calculated according to the speed ratio and transmission efficiency of the engine direct drive. The calculation formula can be:

[0054] Speed_engine_sel=VehicleSpeed_sel÷(2πR_tire)÷60×100×i_ratio

[0055] Among them, Speed_engine_sel is the engine speed corresponding to the selected vehicle speed, VehicleSpeed_sel is the selected vehicle speed, R_tire is the tire radius, and i_ratio is the engine direct drive speed ratio.

[0056] After calculating the corresponding engine speed and torque, the engine torque corresponding to the selected wheel-end output torque is calculated, and the calculation formula can be:

[0057] Torque_engine_sel=Torque_wheel_sel÷i_ratio×η_trans

[0058] Among them, Torque_engine_sel is the engine torque corresponding to the selected wheel-end output torque, Torque_wheel_sel is the selected wheel-end output torque, i_ratio is the engine direct drive speed ratio, and η_trans is the transmission efficiency of the engine direct drive.

[0059] The embodiment of the present application determines the thermal efficiency of the engine based on the engine speed corresponding to the selected vehicle speed and the engine torque corresponding to the selected wheel-end output torque calculated above, and based on the characteristics of the engine itself. The thermal efficiency of the engine refers to the ratio of the heat content of the engine's effective power to the heat content of the fuel consumed per unit time, and is an important indicator for measuring the economy of the engine. The higher the thermal efficiency, the more complete the fuel consumption and the higher the economy.

[0060] Furthermore, the vehicle speed selected above is fixed, different wheel-end output torques are set, the engine specific fuel consumption corresponding to different wheel-end output torques at the same vehicle speed is calculated, and the engine torque corresponding to the highest engine thermal efficiency is selected, such as Figure 4 As shown, Figure 4 The mark point at the mid-peak value is taken as the optimal engine torque (Torque_engine_best) at the engine speed corresponding to the selected vehicle speed.

[0061] In the embodiment of the present application, by selecting different vehicle speeds and repeating the above steps of determining the optimal engine torque, the optimal engine torque at different engine speeds can be obtained, thereby forming a first operating condition line with the highest engine efficiency, such as Figure 5 As shown, the red line portion is the first operating condition line of the engine.

[0062] The embodiment of the present application can comprehensively consider the efficiency and speed ratio of the engine direct drive to determine the first operating condition line of the engine. It is not limited to the engine body, but has a more comprehensive dimension, thereby improving the accuracy of determining the first operating condition line of the engine, thereby improving the economy of the entire vehicle.

[0063] In step S302, a second operating condition line of the engine direct-drive steady-speed driving is determined according to the resistance line of the hybrid vehicle.

[0064] It is understood that the resistance line usually refers to the relationship curve between the various resistances encountered by a hybrid vehicle during driving and the vehicle speed. These resistances include air resistance, rolling resistance, internal mechanical resistance, etc. The resistance line describes how the total resistance that the car needs to overcome changes as the speed increases. In the energy management and performance analysis of hybrid vehicles, the resistance line is an important reference because it directly affects the energy consumption and power requirements of the vehicle. The direct drive steady speed driving of the engine usually refers to the condition where the engine directly drives the wheels and the vehicle travels at a stable speed.

[0065] Optionally, in one embodiment of the present application, a second operating condition line for engine direct drive steady speed driving is determined according to the resistance line of the hybrid vehicle, including: determining the wheel end resistance of the hybrid vehicle according to the resistance line; calculating the corresponding engine torque according to the wheel end resistance to generate the second operating condition line.

[0066] In the actual implementation process, the wheel end resistance of the hybrid vehicle is determined according to the resistance line, and the calculation formula can be:

[0067] Torque_wheel_drag=(a×Vehiclespeed 2 +c)×R_tire

[0068] Among them, Torque_wheel_drag is the wheel end resistance, Vehiclespeed is the current vehicle speed, R_tire is the tire radius, and a, b, and c are the vehicle resistance coefficients.

[0069] After determining the wheel end resistance of the hybrid vehicle, the corresponding engine torque (i.e., the second operating condition line of the engine direct drive steady speed, hereinafter referred to as the second operating condition line) is calculated according to the wheel end resistance calculated above. The calculation formula can be:

[0070] Torque_Engine_drag=Torque_wheel_drag÷i_ratio×η_trans

[0071] Among them, Torque_Engine_drag is the engine torque corresponding to the wheel end resistance, Torque_wheel_drag is the wheel end resistance, i_ratio is the engine direct drive speed ratio, and η_trans is the transmission efficiency of the engine direct drive. This calculation formula calculates the corresponding engine torque according to the wheel end resistance to generate the second operating condition line as follows Figure 6 As shown. Figure 6 The corresponding engine torque can be determined at different engine speeds to make the engine run efficiently.

[0072] The embodiments of the present application can ensure that the engine operates in the most efficient manner in the direct drive mode by accurately calculating the wheel end resistance and the corresponding engine torque, thereby reducing unnecessary energy consumption and improving fuel economy.

[0073] In step S303, the charge and discharge power of the power battery is determined according to the charge and discharge efficiency of the power battery and the temperature rise of the battery.

[0074] It is understandable that the charge and discharge efficiency of a power battery refers to the conversion efficiency between input energy and output energy during the charge and discharge process of the battery, usually expressed as a percentage. High efficiency means that less energy is lost in the form of heat energy during the charge and discharge process, thereby improving energy utilization efficiency and endurance. The performance of the battery is very sensitive to temperature. Within a certain range, an increase in temperature can increase the activity of the battery and increase the charge and discharge power; but too high a temperature can cause the internal chemical reaction rate of the battery to be too fast, aggravating battery aging and even causing safety problems. In summary, the charge and discharge efficiency of the power battery and the temperature rise of the battery need to be taken into account to determine the charge and discharge power of the power battery.

[0075] Optionally, in one embodiment of the present application, the charge and discharge power of the power battery is determined according to the charge and discharge efficiency and battery temperature rise of the power battery, including: calculating the battery discharge power of the power battery of the hybrid vehicle under pure electric driving conditions; determining the charging power of the power battery according to the battery discharge power.

[0076] In the actual implementation process, the battery discharge power of the power battery of the hybrid vehicle under pure electric driving conditions is calculated using the following calculation formula:

[0077] Power_Battery_discharge

[0078] =(a×Vehiclespeed 2 +b×Vehiclespeed+c)×vehiclespeed÷3.6÷1000÷η_trans_2÷η_TM÷η_batdis

[0079] Among them, Power_Battery_discharge is the battery discharge power of the power battery, a, b, c are the vehicle resistance coefficients, η_trans_2 is the pure electric drive mechanical efficiency, η_TM is the drive motor efficiency, and η_batdis is the battery discharge efficiency of the power battery.

[0080] Furthermore, according to the battery discharge power of the power battery calculated above, the charging power of the power battery (i.e., Power_Battery_charge) is determined with the goal of achieving thermal balance of the battery of the whole vehicle under natural heat dissipation conditions. The charging power of the power battery can be obtained by an experimental method, and the principle is as follows: Under a standard environment, the temperature change of the power battery under pure electric driving and engine charging at different vehicle speeds is tested, and the thermal balance of the power battery is achieved by adjusting the charging power of the power battery. When driving at a steady speed, the vehicle speed remains unchanged, the natural heat dissipation of the power battery is a stable value, and the heat generation of the power battery is determined by the charging and discharging power of the power battery; when driving purely electric, the discharge power of the power battery is the power calculated in the above formula; when the engine is charged, the charging power of the power battery is increased by gradually increasing the engine load, and the charging power Power_Battery_charge of the power battery at each vehicle speed is determined with the engine load reaching the maximum or the power battery reaching thermal balance as the boundary.

[0081] The embodiment of the present application can determine the charging power boundary of the power battery through an experimental method, ensure that the battery can achieve thermal balance under different driving conditions, avoid overheating of the battery due to excessive charging power, and require additional energy to dissipate heat for the battery, thereby improving the charging efficiency of the entire vehicle.

[0082] In step S304, a third operating condition line of the engine direct drive is determined according to the first operating condition line, the second operating condition line and the charge and discharge power.

[0083] It is understandable that the third operating condition line of engine direct drive refers to a specific operating condition in which the engine directly drives the wheels and meets the power requirements of the power battery charge and discharge. It comprehensively considers the first and second operating condition lines, as well as the power requirements of the power battery charge and discharge, to determine the most efficient and economical operating point of the engine in direct drive mode.

[0084] Optionally, in one embodiment of the present application, a third operating condition line of direct engine drive is determined based on the first operating condition line, the second operating condition line and the charge and discharge power, including: converting the charge and discharge power into a first engine charging torque; converting the first operating condition line and the second operating condition line into a second engine charging torque; determining the third operating condition line based on the first engine charging torque and the second engine charging torque.

[0085] In the actual implementation process, the charging power of the power battery determined in step S303 is converted into the first engine charging torque, and the calculation formula thereof may be:

[0086] Torque_Engine_Delta1

[0087] =(Power_Battery_charge÷η_batchg÷η_GM÷η_trans_3)×9549.5÷(VehicleSpeed_sel÷(2πR_tire)÷60×1000×i_ratio)

[0088] Among them, Torque_Engine_Delta1 is the first engine charging torque, Power_Battery_charge is the charging power of the power battery, η_batchg is the power battery charging efficiency, η_GM is the charger efficiency, η_trans_3 is the generator mechanical efficiency, η_batdis is the power battery discharge efficiency, VehicleSpeed_sel is the selected vehicle speed, R_tire is the tire radius, and i_ratio is the engine direct drive speed ratio.

[0089] Further, the second engine charging torque is determined according to the first operating condition line determined in step S301 and the second operating condition line determined in step S302, and the calculation formula thereof may be:

[0090] Torque_Engine_Delta2=Torque_engine_best-Torque_Engine_drag

[0091] Wherein, Torque_Engine_Delta2 is the second engine charging torque, Torque_engine_best is the optimal engine torque determined in step S301, and Torque_Engine_drag is the engine torque corresponding to the wheel end resistance determined in step S302.

[0092] After determining the first engine charging torque and the second engine charging torque, the third engine operating condition line is calculated according to the first engine charging torque, the second engine charging torque and the second engine operating condition line determined in step S302. The calculation formula may be:

[0093] Torque_engine_final

[0094] =Torque_Engine_drag+min(Torque_Engine_Delta1,Torque_Engine_Delta2)

[0095] Among them, Torque_engine_final is the engine direct drive running torque, Torque_Engine_drag is the engine torque corresponding to the wheel end resistance determined in step S302, Torque_Engine_Delta1 is the first engine charging torque, Torque_Engine_Delta2 is the second engine charging torque, and min(Torque_Engine_Delta1, Torque_Engine_Delta2) is the smaller value selected between Torque_Engine_Delta1 and Torque_Engine_Delta2. The third engine operating condition line thus calculated is as follows: Figure 7 As shown by the red line in Figure 7 It can be seen that the corresponding optimal engine torque can be obtained from the engine speed.

[0096] The embodiment of the present application can improve energy utilization efficiency by converting the power battery charging and discharging power into the first engine charging torque, ensuring the precise match between the engine output and the power battery demand, and converting the first operating condition line and the second operating condition line into the second engine charging torque, and determining the third operating condition line based on the first engine charging torque and the second engine charging torque, ensuring that the engine operates in the most efficient area while meeting the charging demand, thereby reducing energy waste and improving economy.

[0097] In step S305 , the required torque of the drive motor is determined according to the third operating condition line and the vehicle required torque of the hybrid vehicle.

[0098] It is understood that the vehicle demand torque refers to the total torque that the drive system (including but not limited to the engine and drive motor) needs to provide to meet the driving requirements of the hybrid vehicle such as acceleration, climbing or maintaining a stable speed under the current driving conditions. It is determined by many factors such as the driving state of the hybrid vehicle (including but not limited to vehicle speed, road conditions), the driver's operation (including but not limited to the depth of the accelerator or accelerator pedal) and the vehicle load. In order to ensure that the vehicle can drive in the desired manner, such as including but not limited to acceleration, maintaining a stable speed or climbing, the output torque of the drive motor must match the vehicle demand torque.

[0099] In the actual execution process, the required torque of the drive motor is determined according to the third operating condition line of the engine calculated in step S304 and the required torque of the whole vehicle, and the calculation formula thereof can be:

[0100] Torque_TM_final=Torque_driver_request-Torque_engine_final

[0101] Among them, Torque_TM_final is the drive motor torque, Torque_dirver_request is the driver's demand torque, and Torque_engine_final is the engine direct drive torque. The drive motor torque obtained by this calculation method is Figure 8 As shown by the green line in the middle, it can be seen that the drive motor torque is obtained by translating the engine torque in the negative direction of the Y axis, and this translation distance is the engine torque.

[0102] The purpose of the embodiment of the present application is to keep the torque of the engine stable, and the working condition of the engine will not change even if the driver steps on the accelerator or releases the accelerator. In the engine direct drive mode, the engine speed is coupled with the vehicle speed, and the vehicle speed will not change rapidly. The engine speed and torque are kept in a relatively stable state, so that the engine operation is stable, thereby improving the economy of the whole vehicle. At the same time, the required torque is responded to by the driving motor torque. Since the motor torque has a fast response speed and high precision, it can well respond to the driver's needs and control the vehicle's drivability, which is conducive to improving the power and drivability of the whole vehicle.

[0103] Specifically, combined Fig. 9 As shown, the working principle of the control method of the hybrid vehicle of the present application embodiment is described in detail with an embodiment. Fig. 9 As shown, the control method steps of the hybrid vehicle are as follows:

[0104] Step S901: Determine the optimal operating line of the engine.

[0105] The operating condition line with the highest engine efficiency, that is, the first operating condition line of the engine, is determined according to the characteristics of the engine.

[0106] Step S902: Determine the engine direct drive steady speed operating line.

[0107] The operating condition of the engine's direct-drive steady-speed driving is determined based on the resistance line of the entire vehicle, that is, the second operating condition line of the engine is determined.

[0108] Step S903: Determine the charging and discharging power of the power battery.

[0109] The charging and discharging power of the power battery is determined based on the charging and discharging efficiency of the power battery and the temperature rise of the battery.

[0110] Step S904: The engine direct drive operation line is determined.

[0111] The engine direct drive operating line, that is, the engine third operating line, is determined based on the first operating line of the engine calculated in step S901, the second operating line of the engine calculated in step S902, and the power battery charge and discharge power calculated in step S903.

[0112] Step S905: Determine the operating condition of the drive motor.

[0113] The required torque of the drive motor is determined according to the third operating condition line of the engine calculated in step S904 and the required torque of the entire vehicle.

[0114] In some embodiments, the first operating condition line is first determined according to the engine characteristics, the second operating condition line is determined based on the vehicle resistance line, and the charging and discharging power of the power battery is obtained in combination with the charging and discharging efficiency and temperature rise of the power battery. Then, the third operating condition line of the engine is determined by combining the calculation results of the first three items. Finally, the required torque of the drive motor is determined based on the third operating condition line of the engine and the required torque of the vehicle. The relevant factors of the key components of the hybrid vehicle are fully considered. Through precise calculation and comprehensive analysis, the optimal matching of the operating conditions of each component is achieved, the energy utilization efficiency is improved, the power performance and driving stability of the vehicle are enhanced, the energy consumption is reduced, the service life of the key components of the vehicle is extended, and the overall performance and user experience of the vehicle are improved.

[0115] According to the control method of the hybrid vehicle proposed in the embodiment of the present application, the operating conditions of the engine and the drive motor and the charging and discharging power of the power battery can be accurately determined and optimized by analyzing and integrating the relevant parameters of the key components of the hybrid vehicle, and based on multi-dimensional data such as the engine characteristics, the vehicle resistance line, the power battery status and the required torque of the whole vehicle, the first operating condition line with the highest efficiency of the engine, the second operating condition line of the engine direct drive at a steady speed, and the third operating condition line of the engine direct drive are determined in turn, and finally the required torque of the drive motor is obtained, which fully considers the actual conditions of the key parts of the hybrid vehicle, realizes efficient and coordinated operation of the system, improves energy utilization efficiency, enhances the power performance and driving stability of the whole vehicle, and can effectively extend the service life of the power battery and reduce energy consumption, thereby improving the economy of the whole vehicle.

[0116] Next, the control device for a hybrid vehicle according to an embodiment of the present application will be described with reference to the accompanying drawings.

[0117] Fig.10 It is a block diagram of a control device for a hybrid vehicle according to an embodiment of the present application.

[0118] like Fig.10 As shown, the control device 10 of the hybrid vehicle includes: a first acquisition module 100 , a second acquisition module 200 , a third acquisition module 300 , a fourth acquisition module 400 and a control module 500 .

[0119] Specifically, the first acquisition module 100 is used to determine a first operating condition line with the highest efficiency of the engine according to the characteristics of the engine of the hybrid vehicle.

[0120] The second acquisition module 200 is used to determine a second operating condition line of the engine direct-drive steady-speed driving according to the resistance line of the hybrid vehicle.

[0121] The third acquisition module 300 is used to determine the charge and discharge power of the power battery according to the charge and discharge efficiency of the power battery and the temperature rise of the battery.

[0122] The fourth acquisition module 400 is used to determine a third operating condition line of the engine direct drive according to the first operating condition line, the second operating condition line and the charge and discharge power.

[0123] The control module 500 is used to determine the required torque of the drive motor according to the third operating condition line and the vehicle required torque of the hybrid vehicle.

[0124] Optionally, in one embodiment of the present application, the first acquisition module 100 includes: a first calculation unit and a second calculation unit.

[0125] The first calculation unit is used to calculate the corresponding engine speed and engine torque based on the output torque of any wheel end at the target vehicle speed.

[0126] The second calculation unit is used to determine the thermal efficiency of the engine according to the engine speed and the engine torque, and change the output torque to calculate the engine specific fuel consumption of the engine, and determine the engine torque corresponding to the high thermal efficiency of the engine as the optimal engine torque at the engine speed corresponding to the target vehicle speed, and change the target vehicle speed until the preset iteration stop condition is reached to generate a first operating condition line.

[0127] Optionally, in one embodiment of the present application, the second acquisition module 200 includes: a third calculation unit and a fourth calculation unit.

[0128] The third calculation unit is used to determine the wheel end resistance of the hybrid vehicle according to the resistance line.

[0129] The fourth calculation unit is used to calculate the corresponding engine torque according to the wheel end resistance to generate a second operating condition line.

[0130] Optionally, in one embodiment of the present application, the third acquisition module 300 includes: a fifth calculation unit and a matching unit.

[0131] Among them, the fifth calculation unit is used to calculate the battery discharge power of the power battery of the hybrid vehicle under pure electric driving conditions.

[0132] The matching unit is used to determine the charging power of the power battery according to the battery discharge power.

[0133] Optionally, in one embodiment of the present application, the fourth acquisition module 400 includes: a first conversion unit, a second conversion unit and a generation unit.

[0134] Among them, the first conversion unit is used to convert the charging and discharging power into the first engine charging torque.

[0135] The second conversion unit is used to convert the first operating condition line and the second operating condition line into a second engine charging torque.

[0136] A generating unit is used to determine a third operating condition line according to the first engine charging torque and the second engine charging torque.

[0137] It should be noted that the above explanation of the embodiment of the control method for a hybrid vehicle is also applicable to the control device for the hybrid vehicle of this embodiment, and will not be repeated here.

[0138] According to the control device of the hybrid vehicle proposed in the embodiment of the present application, the operating conditions of the engine and the drive motor and the charging and discharging power of the power battery can be accurately determined and optimized by analyzing and integrating the relevant parameters of the key components of the hybrid vehicle, and based on multi-dimensional data such as the engine characteristics, the vehicle resistance line, the power battery status and the required torque of the whole vehicle, the first operating condition line with the highest efficiency of the engine, the second operating condition line of the engine direct drive at a steady speed, and the third operating condition line of the engine direct drive are determined in turn, and finally the required torque of the drive motor is obtained, which fully considers the actual conditions of the key parts of the hybrid vehicle, realizes efficient and coordinated operation of the system, improves energy utilization efficiency, enhances the power performance and driving stability of the whole vehicle, and can effectively extend the service life of the power battery and reduce energy consumption, thereby improving the economy of the whole vehicle.

[0139] Fig.11 A schematic diagram of the structure of a hybrid vehicle provided in an embodiment of the present application. The hybrid vehicle may include:

[0140] A memory 1101 , a processor 1102 , and a computer program stored in the memory 1101 and executable on the processor 1102 .

[0141] When the processor 1102 executes the program, the control method of the hybrid vehicle provided in the above embodiment is implemented.

[0142] Furthermore, the hybrid vehicle further comprises:

[0143] The communication interface 1103 is used for communication between the memory 1101 and the processor 1102 .

[0144] The memory 1101 is used to store computer programs that can be executed on the processor 1102 .

[0145] The memory 1101 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0146] If the memory 1101, the processor 1102 and the communication interface 1103 are implemented independently, the communication interface 1103, the memory 1101 and the processor 1102 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig.11 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0147] Optionally, in a specific implementation, if the memory 1101, the processor 1102 and the communication interface 1103 are integrated on a chip, the memory 1101, the processor 1102 and the communication interface 1103 can communicate with each other through an internal interface.

[0148] The processor 1102 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0149] The embodiment of the present application also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the control method of the hybrid vehicle as described above is implemented.

[0150] An embodiment of the present application also provides a computer program product, including a computer program, which, when executed, is used to implement the above hybrid vehicle control method.

[0151] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0152] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0153] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0154] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways as necessary and then storing it in a computer memory.

[0155] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. If implemented by hardware, as in another embodiment, it can be implemented by any one or a combination of multiple of the following technologies known in the art: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0156] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0157] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0158] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A control method for a hybrid vehicle, characterized in that: The following steps are involved: Determining a first operating condition line at which the engine has the highest efficiency according to the characteristics of the engine of the hybrid vehicle; Determining a second operating condition line of the engine direct-drive steady-speed running according to the resistance line of the hybrid vehicle; Determining the charge and discharge power of the power battery according to the charge and discharge efficiency of the power battery and the temperature rise of the battery; Determine a third operating condition line of the engine direct drive according to the first operating condition line, the second operating condition line and the charge and discharge power; The required torque of the drive motor is determined according to the third operating condition line and the whole vehicle required torque of the hybrid vehicle.

2. The method according to claim 1, characterized in that: The method of determining the first operating condition line with the highest efficiency of the engine according to the characteristics of the engine of the hybrid vehicle comprises: Based on the output torque of any wheel end at the target vehicle speed, the corresponding engine speed and engine torque are calculated; The thermal efficiency of the engine is determined according to the engine speed and the engine torque, and the output torque is replaced to calculate the engine specific fuel consumption of the engine, and the engine torque corresponding to the high engine thermal efficiency is determined as the optimal engine torque at the engine speed corresponding to the target vehicle speed, and the target vehicle speed is replaced until a preset iteration stop condition is reached to generate the first operating condition line.

3. The method according to claim 1, characterized in that The method of determining the second operating condition line of the engine direct-drive steady-speed driving according to the resistance line of the hybrid vehicle comprises: determining the wheel end resistance of the hybrid vehicle according to the resistance line; The corresponding engine torque is calculated according to the wheel end resistance to generate the second operating condition line.

4. The method according to claim 1, characterized in that: The determining the charge and discharge power of the power battery according to the charge and discharge efficiency of the power battery and the temperature rise of the battery includes: Calculating the battery discharge power of the power battery of the hybrid electric vehicle under pure electric driving conditions; The charging power of the power battery is determined according to the battery discharging power.

5. The method according to claim 1, characterized in that The determining of the third operating condition line of the engine direct drive according to the first operating condition line, the second operating condition line and the charge and discharge power comprises: converting the charge and discharge power into a first engine charging torque; converting the first operating condition line and the second operating condition line into a second engine charging torque; The third operating condition line is determined according to the first engine charging torque and the second engine charging torque.

6. A control device for a hybrid vehicle, characterized in that: include: A first acquisition module, configured to determine a first operating condition line with the highest efficiency of the engine according to the characteristics of the engine of the hybrid vehicle; A second acquisition module is used to determine a second operating condition line of the engine direct-drive steady-speed driving according to the resistance line of the hybrid vehicle; A third acquisition module, used to determine the charge and discharge power of the power battery according to the charge and discharge efficiency and battery temperature rise of the power battery; a fourth acquisition module, configured to determine a third operating condition line of the engine direct drive according to the first operating condition line, the second operating condition line and the charge and discharge power; The control module is used to determine the required torque of the drive motor according to the third operating condition line and the vehicle required torque of the hybrid vehicle.

7. The device according to claim 6, characterized in that The engine high-efficiency operating condition determination module comprises: A first calculation unit, configured to calculate the corresponding engine speed and engine torque based on the output torque of any wheel end at the target vehicle speed; A second calculation unit is used to determine the thermal efficiency of the engine according to the engine speed and the engine torque, and to change the output torque to calculate the engine specific fuel consumption of the engine, and to determine the engine torque corresponding to the high engine thermal efficiency as the optimal engine torque at the engine speed corresponding to the target vehicle speed, and to change the target vehicle speed until a preset iteration stop condition is reached to generate the first operating condition line.

8. A hybrid vehicle, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the control method for a hybrid electric vehicle as claimed in any one of claims 1 to 5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the control method of the hybrid vehicle as described in any one of claims 1 to 5.

10. A computer program product, comprising a computer program, characterized in that The computer program is executed to implement the control method of the hybrid vehicle according to any one of claims 1 to 5.

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