Torque determination method and device, storage medium and vehicle

Abstract

The invention provides a torque determination method, device and equipment and a vehicle, relates to the technical field of hybrid electric vehicles, and aims to realize intelligence and self-adaption of torque distribution in a parallel mode and remarkably improve the comprehensive performance of the hybrid electric vehicle. The method comprises the steps that under the condition that a vehicle is in a parallel mode, the current torque control mode of an engine is determined as a target control mode; under the target control mode, determining a first target torque of the engine based on the torque required by the driver and a universal characteristic curve of the engine; under the condition that the driving torque of the driving motor is limited and / or the charging and discharging power of the battery pack is limited, the current torque control mode of the engine is switched from the target control mode to the following control mode; and in the following control mode, based on the torque required by the driver, determining a second target torque of the engine.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of hybrid electric vehicles, in particular, to a torque determination method and device, a storage medium and a vehicle. BACKGROUND

[0002] In parallel mode, the hybrid electric vehicle needs to consider both the vehicle power and economy. Usually, the engine is controlled in the optimal working interval to ensure the economy of the vehicle; but in parallel mode, the power source of the vehicle comes from the engine and the battery pack, and is limited by the external characteristics of the engine, the driving motor, the generator and the charging and discharging power of the battery pack; when the external characteristics of the driving motor are limited or the charging and discharging power of the battery pack is limited, timely adjustment of the power output of the engine will cause insufficient power of the vehicle or increase fuel consumption. SUMMARY

[0003] Embodiments of the present application provide a torque determination method and device, a storage medium and a vehicle, which are designed to overcome the above problems or at least partially solve the above problems.

[0004] The first aspect of the embodiments of the present application provides a torque determination method, which comprises: In the case that the vehicle is in parallel mode, determining that the current torque control mode of the engine is a target control mode; In the target control mode, determining a first target torque of the engine based on the driver demand torque and the universal characteristic curve of the engine; In the case that the driving torque of the driving motor is limited and / or the charging and discharging power of the battery pack is limited, switching the current torque control mode of the engine from the target control mode to a follow-up control mode; In the follow-up control mode, determining a second target torque of the engine based on the driver demand torque.

[0005] In an optional implementation, in the target control mode, determining a first target torque of the engine based on the driver demand torque and the universal characteristic curve of the engine comprises: obtaining a basic torque of the engine working in the optimal fuel economy interval according to the actual speed of the engine, the driver demand torque and the universal characteristic curve of the engine; obtaining a current residual power difference value according to the actual residual power of the vehicle and the current target residual power, the current target residual power being associated with the current oil-electricity use strategy of the vehicle in parallel mode; querying a corresponding relationship among the residual power difference value, the oil-electricity use strategy and the torque correction coefficient to obtain a current torque correction coefficient according to the current residual power difference value and the current oil-electricity use strategy. correct the base torque according to the current torque correction coefficient and the actual rotating speed of the engine in the engine economic zone torque upper and lower limits to obtain the first target torque.

[0006] In an optional implementation, in the following control mode, the second target torque of the engine is determined based on the driver demand torque, comprising: determining the smaller one of the driver demand torque and the engine torque limit value as the second target torque.

[0007] In an optional implementation, the method further comprises: querying a corresponding relationship among the current accelerator pedal change rate, the current vehicle speed and the gradient correction coefficient according to the current accelerator pedal change rate and the current vehicle speed to obtain the current gradient correction coefficient; obtaining the target torque gradient in the following control mode according to the engine maximum torque gradient, the engine economic zone torque gradient and the current gradient correction coefficient.

[0008] In an optional implementation, after obtaining the target torque gradient in the following control mode, the method further comprises: detecting whether a duration, in which the fluctuation amplitude of the current accelerator pedal change rate is less than a target fluctuation amplitude, reaches a target duration in the following control mode; in a case where the duration reaches the target duration, gradually reducing the current gradient correction coefficient to zero within the target duration; updating the target torque gradient in the following control mode based on the reduced current gradient correction coefficient; wherein, in a case where the reduced current gradient correction coefficient is equal to zero, the target torque gradient in the following control mode is the smaller one of the engine maximum torque gradient and the engine economic zone torque gradient.

[0009] In an optional implementation, the method further comprises: in a case where the driving torque of the driving motor is not limited and the charging and discharging power of the battery pack is not limited, maintaining the current torque control mode of the engine as the target control mode.

[0010] In an optional implementation, the method further comprises: in a case where the driving torque of the driving motor is not limited and the charging and discharging power of the battery pack is not limited, detecting whether the vehicle enters a coasting state according to the driver demand torque, the accelerator pedal state and the actual rotating speed of the engine; In a case where the vehicle enters the coasting state, a fuel cut control instruction is sent to the engine, and the first target torque of the engine is determined as a friction torque. After the vehicle exits the coasting state, the first target torque of the engine is determined based on the driver demand torque and the universal characteristic curve of the engine.

[0011] The second aspect of the embodiment of the present application provides a torque distribution device, and the device comprises: The first determination module is configured to determine, in a case where the vehicle is in a parallel mode, that a current torque control mode of the engine is a target control mode. The second determination module is configured to determine, in the target control mode, the first target torque of the engine based on a driver demand torque and a universal characteristic curve of the engine. The switching module is configured to switch, in a case where a driving torque of the driving motor is limited and / or a charging and discharging power of the battery pack is limited, the current torque control mode of the engine from the target control mode to a follow-up control mode. The third determination module is configured to determine, in the follow-up control mode, the second target torque of the engine based on the driver demand torque.

[0012] The third aspect of the embodiment of the present application provides an electronic device, which comprises a processor, a memory, and a computer program stored in the memory and executable on the processor, and the processor implements the torque determination method of the first aspect of the embodiment of the present application when executing the computer program.

[0013] The fourth aspect of the embodiment of the present application provides a vehicle, which comprises an engine, a generator, a driving motor, and a vehicle controller, and the vehicle controller is configured to execute the torque determination method of the first aspect of the embodiment of the present application.

[0014] The fifth aspect of the embodiment of the present application provides a computer readable storage medium, and the computer readable storage medium stores a computer program, and the computer program is executable on a processor to implement the torque determination method of the first aspect of the embodiment of the present application.

[0015] In the torque determination method provided in the application, when the vehicle is in the parallel mode, the current torque control mode of the engine is first determined as the target control mode, and a first target torque is determined based on the driver demand torque and the universal characteristic curve of the engine, and the engine is controlled in the optimal working interval to ensure the economy of the vehicle. When the driving torque of the driving motor is limited and / or the charging and discharging power of the battery pack is limited, the current torque control mode of the engine is switched to the follow-up control mode, and a second target torque of the engine is determined based on the driver demand torque. When a special working condition is identified, the engine torque output can be adjusted in time to avoid power shortage, and the power performance and safety of the vehicle under different vehicle states and different power are improved. The application realizes the intelligentization and self-adaptation of torque distribution in the parallel mode, and significantly improves the comprehensive performance of the hybrid vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed to be used in the description of the embodiments of the application will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0017] Figure 1 is a schematic diagram of a mechanical and electrical architecture of a power system of a hybrid electric vehicle according to the application; Figure 2 is a step flowchart of the torque determination method according to an embodiment of the application; Figure 3 is a step flowchart of the torque determination method according to an embodiment of the application; Figure 4 is a structural schematic diagram of the torque determination device according to an embodiment of the application; Figure 5 is a schematic diagram of an electronic device according to an embodiment of the application. DETAILED DESCRIPTION

[0018] The technical solutions of the embodiments of the application will be described clearly and completely in the following description with reference to the drawings of the embodiments of the application. Obviously, the described embodiments are only some embodiments of the application, not all embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0019] In the drawings, the size, the thickness of a layer, or a region of a constituent element shown in some cases can be exaggerated for the purpose of making the present disclosure clear. Therefore, the present disclosure is not necessarily limited to the size, the shape of a component shown in the drawings and the actual scale. Further, the drawings schematically show ideal examples, and the present disclosure is not limited to the shape or numerical value shown in the drawings.

[0020] In the parallel mode, the engine and the drive motor directly drive the wheels, and the power sources work together. Figure 1 is a schematic diagram of a mechanical and electrical architecture of a power system of a hybrid vehicle according to the present application, as Figure 1 indicated, the vehicle dynamics controller VDC can obtain signals such as vehicle speed, engine torque and speed, drive motor torque and speed, battery pack SOC (State of Charge), battery pack peak charge and discharge power limit, and vehicle mode through the local network control buses EVCAN1 and EVCAN2. The internal diagnostic module can monitor clutch fault status, solenoid fault status, and pressure sensor fault status in real time. The engine, clutch, generator, and drive motor are mechanically connected through gears and shafts. The generator, drive motor, and battery pack are electrically connected. The torque transmission path is the engine, clutch, differential, wheels, and drive motor, differential, and wheels. In the parallel mode, the engine and the drive motor drive the vehicle together.

[0021] Referring to Figure 2 , Figure 2 is a step flowchart of a torque determination method according to an embodiment of the present application. As Figure 2 indicated, the method includes the following steps S21-S24: Step S21: In the case where the vehicle is in the parallel mode, the current torque control mode of the engine is determined to be the target control mode.

[0022] In this embodiment, when the vehicle enters the parallel mode (such as high-speed cruising, sudden acceleration, etc.), for example, when the torque distribution mode of the vehicle is in the parallel mode, the vehicle controller or the powertrain control module automatically sets the current torque control mode of the engine to the target control mode, and the target control mode is the vehicle economy priority mode, which controls the engine in the optimal working interval to ensure the economy of the vehicle.

[0023] Step S22: In the target control mode, based on the driver demand torque and the universal characteristic curve of the engine, the first target torque of the engine is determined.

[0024] In this embodiment, the driver demand torque can be calculated through the accelerator pedal opening degree, vehicle speed, driving mode, etc. Specifically, the pedal position can be converted into initial torque demand through a pre-established accelerator pedal opening degree-initial torque demand curve, and the initial torque demand can be adjusted according to the actual vehicle speed and driving mode, and finally the driver demand torque is obtained, wherein the initial torque demand can be adjusted according to the pre-established corresponding relationship between the vehicle speed and the first adjustment coefficient, and according to the pre-established corresponding relationship between the driving mode and the second adjustment coefficient. Generally speaking, the higher the vehicle speed, the greater the driving resistance, so the initial torque demand can be adjusted according to the vehicle speed to ensure that the vehicle can overcome the resistance and maintain stable driving; different driving modes (here referring to the pure electric priority, fuel priority, automatic mode in parallel mode) have different power output characteristics and driving feelings, so the initial torque demand can be further adjusted according to the driving mode. The universal characteristic curve of the engine is a comprehensive embodiment of the engine performance, which shows the fuel consumption rate, efficiency and other parameters of the engine under different speeds and torques. In the target control mode, the corresponding best torque point is found on the universal characteristic curve of the engine according to the actual speed of the engine combined with the driver demand torque, and then the best torque point is corrected to obtain the first target torque of the engine, which can control the engine to run in the best working interval and ensure the economy of the vehicle.

[0025] Step S23: In the case where the driving torque of the driving motor is limited and / or the charging and discharging power of the battery pack is limited, the current torque control mode of the engine is switched from the target control mode to the follow-up control mode. In this embodiment, the low-temperature environment or the fault of the battery pack causes the charging and discharging power (charging power and discharging power) of the battery pack to be limited, and the overheating or fault of the electric drive system causes the driving torque of the motor to be limited. The vehicle controller can compare the obtained driving torque limit value of the driving motor and the charging and discharging power limit value of the battery pack with the respective pre-set threshold values, to determine whether the driving torque of the driving motor is limited and / or the charging and discharging power of the battery pack is limited, and if so, the current torque control mode of the engine is immediately switched from the target control mode to the follow-up control mode, in which the driver torque demand is followed, the maximum torque output capability of the engine is exerted, and the vehicle power and safety are improved.

[0026] Step S24: In the follow-up control mode, the second target torque of the engine is determined based on the driver demand torque.

[0027] In the follow-up control mode, the second target torque of the engine is determined directly according to the driver demand torque. The engine torque output can be adjusted in time in the limiting working condition, power deficiency is avoided, and the power performance and safety of the whole vehicle in response to different vehicle states and different electric quantities are improved.

[0028] In the torque determination method provided in the application, when the vehicle is in the parallel mode, the current torque control mode of the engine is determined as the target control mode, and the first target torque is determined based on the driver demand torque and the universal characteristic curve of the engine, so that the engine is controlled in the optimal working interval to ensure the economy of the whole vehicle. When the driving torque of the driving motor is limited or the charging and discharging power of the battery pack is limited, the current torque control mode of the engine is switched to the follow-up control mode, and the second target torque of the engine is determined based on the driver demand torque, so that the engine torque output can be adjusted in time to avoid power deficiency, and the power performance and safety of the whole vehicle in response to different vehicle states and different electric quantities are improved. The application realizes the intelligentization and self-adaptation of torque distribution in the parallel mode, and significantly improves the comprehensive performance of the hybrid vehicle.

[0029] In an embodiment, the application further provides a torque determination method, in which the above-mentioned step S22 “determining the first target torque of the engine in the target control mode based on the driver demand torque and the universal characteristic curve of the engine” can specifically include the following steps S31-S34: Step S31: obtaining the basic torque of the engine working in the optimal fuel economy interval according to the actual speed of the engine, the driver demand torque and the universal characteristic curve of the engine.

[0030] In the embodiment, the basic torque of the engine working in the optimal fuel economy interval is obtained by querying the engine basic torque request table according to the actual speed of the engine and the driver demand torque (expected torque). The engine basic torque request table is determined by the universal characteristic curve of the engine and three-high calibration. The three-high calibration refers to engine performance testing and parameter calibration in three extreme environments of high temperature, high altitude and high cold; the optimal economy torque points at each speed are determined through the universal characteristic curve, and the deviation caused by the environment (such as torque degradation in high-altitude areas) is corrected through three-high test verification of the theoretical data to form the final engine basic torque request table, as shown in Table 1.

[0031] Table 1. Engine basic torque request table

[0032] Step S32: Obtain a current remaining electric quantity difference value according to the actual remaining electric quantity of the vehicle and a current target remaining electric quantity, the current target remaining electric quantity being associated with a current oil-electricity use strategy of the vehicle in the parallel mode.

[0033] In this embodiment, after the basic torque of the engine operating in the optimal fuel economy interval is obtained, the basic torque needs to be corrected in order to maintain the SOC balance of the system, to ensure that the vehicle has sufficient backup power in the parallel mode, and to ensure that the battery pack has sufficient recovery capability when braking energy is recovered. Specifically, based on the current oil-electricity use strategy of the vehicle in the parallel mode, a current target remaining electric quantity is determined, and the oil-electricity use strategy includes: pure electricity priority, fuel priority, automatic, and forced pure electricity. Different oil-electricity use strategies correspond to different target remaining electric quantities. Pure electricity priority: in the parallel mode, the drive motor is still required to bear more torque as much as possible, and the engine only supplements the insufficient part. Fuel priority: the engine is the main power source, and the drive motor is auxiliary. Automatic: the system dynamically allocates the torque of the engine and the drive motor. Forced pure electricity: even if the parallel mode is entered, the engine intervention will be limited (only in extreme cases). According to the current target remaining electric quantity and the monitored actual remaining electric quantity of the vehicle, a current remaining electric quantity difference value is calculated: ΔSOC = target SOC - actual SOC.

[0034] Step S32: According to the current remaining electric quantity difference value and the current oil-electricity use strategy, the correspondence among the remaining electric quantity difference value, the oil-electricity use strategy, and the torque correction coefficient is queried to obtain a current torque correction coefficient.

[0035] In this embodiment, according to the current remaining electric quantity difference value and the current oil-electricity use strategy, the correspondence among the remaining electric quantity difference value, the oil-electricity use strategy, and the torque correction coefficient is queried to obtain a current torque correction coefficient , wherein the correction coefficient value range is [0.8, 1.2].

[0036] Table 2. Engine basic torque correction coefficient table

[0037] Step S33: According to the current torque correction coefficient and the actual speed of the engine in the upper and lower limits of the engine economic interval torque, the basic torque is corrected to obtain the first target torque of the engine.

[0038] In this embodiment, the basic torque of the engine is corrected according to the current torque correction coefficient, and is limited within the optimal economic interval to obtain the first target torque of the engine (target control mode engine torque request):

[0039]

[0040] wherein, is the engine torque request; is the base torque of the engine; is the current torque correction factor of the base torque of the engine; is the lower limit of the engine economy band torque at the actual engine speed; is the upper limit of the engine economy band torque at the actual engine speed, determined by the engine's universal characteristic curve.

[0041] drive motor torque request: ; generator torque request: ; wherein, is the drive motor torque request; is the driver demand torque; is the actual engine torque, which is the actual torque generated by the engine according to the corrected first target torque; is the drive motor torque limit; is the generator torque request.

[0042] After obtaining the first target torque of the engine under the target control mode, the drive motor torque request of the drive motor and the generator torque request can be further determined. Since the total output torque of the system is provided by the engine and the drive motor in the parallel mode, the generator torque request is zero. Then, the torque distribution of the generator and the drive motor of the vehicle can be performed according to the determined first target torque and the drive motor torque request, so as to realize the torque distribution of the target control mode in the parallel mode, and maximize the fuel economy of the whole vehicle under the premise of ensuring the power performance.

[0043] Engine torque follow control is activated: in a low-temperature environment or when a battery pack malfunctions to limit the discharge power of the battery, the electric drive system overheats or malfunctions to limit the driving torque of the motor, the driver demand torque is greater than the maximum torque in the economic zone of the engine, and the engine torque output is still limited in the optimal economic zone, while the electric drive system cannot provide additional driving power compensation, which may cause insufficient power of the vehicle and bring certain driving risks. Further, in a low-temperature environment or when a battery pack malfunctions to limit the charging power of the battery pack, if the engine output torque is still limited in the optimal economic zone, the battery pack may be overcharged, reducing the service life of the battery pack. The vehicle controller identifies the following working conditions and selects the engine torque control mode in time when driving in parallel mode to activate the engine torque follow control, so that the engine jumps out of the optimal economic working zone to follow the driver torque demand, the maximum torque output of the engine is used to improve the power performance of the vehicle, or the engine torque output is reduced to ensure sufficient energy recovery capacity of the battery pack and prevent the battery pack from being overcharged, further improving the power performance and safety of the vehicle.

[0044] Driving torque limited working condition of the drive motor: the vehicle is in parallel mode driving; the driver demand torque is greater than the maximum torque in the economic zone of the engine, wherein is the maximum torque limit in the economic zone of the engine; the driving torque of the drive motor is limited, <first limited threshold (such as 20 Nm), wherein is the driving torque limit of the drive motor.

[0045] Discharge power limited working condition of the battery pack: the vehicle is in parallel mode driving; the driver demand torque is greater than the maximum torque in the economic zone of the engine, wherein is the maximum torque limit in the economic zone of the engine; the discharge power of the battery pack is limited, <second limited threshold (such as 10 kw), wherein is the discharge power limit of the battery pack.

[0046] Charging power limited working condition of the battery pack: the vehicle is in parallel mode driving; the charging power of the battery pack is limited, <third limited threshold, wherein is the charging power limit of the battery pack.

[0047] When the vehicle controller identifies the above limited working conditions, the current torque control mode of the engine is immediately switched from the target control mode to the follow control mode, the engine torque follow control is activated, the engine torque request follows the driver demand torque, and the safe driving of the vehicle is ensured.

[0048] In one embodiment, this application also provides a torque determination method, in which step S24, "under the following control mode, determining the second target torque of the engine based on the driver's required torque," specifically includes the following step S41: Step S41: Determine the smaller of the driver's required torque and the engine torque limit as the second target torque.

[0049] In this embodiment, under the follow control mode, the smaller of the driver's required torque and the engine torque limit is determined as the second target torque (engine torque request under the follow control mode): ; Drive motor torque request: ; Generator torque request: .

[0050] in, For engine torque request; Torque required by the driver; This is the engine torque limit; For the torque request of the drive motor; This refers to the actual torque of the engine. This is the torque limit for the drive motor; For generator torque request.

[0051] After obtaining the second target torque of the engine under the follow control mode, this application can further determine the torque request of the drive motor and the torque request of the generator. Then, based on the determined second target torque and drive motor torque request, torque is distributed to the generator and drive motor of the vehicle, realizing torque distribution in the follow control mode under parallel operation, ensuring the vehicle's power and safety under special operating conditions.

[0052] In one embodiment, this application also provides a torque determination method, which further includes the following steps S51-S52: Step S51: Based on the current accelerator pedal change rate and the current vehicle speed, query the correspondence between the accelerator pedal change rate, vehicle speed, and gradient correction coefficient to obtain the current gradient correction coefficient.

[0053] In this embodiment, when the current torque control mode of the engine is switched from the target control mode to the follow-up control mode, that is, from the economic zone to the torque follow-up control, the engine torque gradient needs to be corrected by the accelerator pedal change rate and the current vehicle speed to ensure smooth torque transition and improve vehicle power. The corresponding relationship among the accelerator pedal change rate, the vehicle speed and the gradient correction coefficient can be obtained according to the current accelerator pedal change rate and the current vehicle speed, as shown in Table 3, to obtain the current gradient correction coefficient.

[0054] Table 3. Torque gradient correction coefficient table

[0055] Step S52: obtaining the target torque gradient in the follow-up control mode according to the engine maximum torque gradient, the engine economic zone torque gradient and the current gradient correction coefficient.

[0056] In this embodiment, the torque gradient refers to the change rate of the engine output torque of the vehicle with time. The engine torque gradient is corrected according to the engine maximum torque gradient, the engine economic zone torque gradient and the current gradient correction coefficient to obtain the target torque gradient in the follow-up control mode:

[0057] wherein, is the engine maximum torque gradient; is the engine torque gradient in the economic zone; is the current gradient correction coefficient. When switching from the economic zone to the torque follow-up control, the torque gradient is corrected to make the change of the engine torque more smooth, avoid affecting the vehicle smoothness and ensure the driving performance and stability of the vehicle.

[0058] In one embodiment, the application further provides a torque determination method, after obtaining the target torque gradient in the follow-up control mode, the method further includes the following steps S61-S63: Step S61: detecting whether the duration that the fluctuation amplitude of the current accelerator pedal change rate is less than the target fluctuation amplitude reaches a target duration in the follow-up control mode; Step S62: gradually reducing the current gradient correction coefficient to zero within the target duration in the case that the duration reaches the target duration; Step S63: updating the target torque gradient in the follow-up control mode based on the reduced current gradient correction coefficient; wherein, in the case that the reduced current gradient correction coefficient is equal to zero, the target torque gradient in the follow-up control mode is the smaller one of the engine maximum torque gradient and the engine economic zone torque gradient.

[0059] In the embodiment, to avoid that the long-time torque change rate is too large after the torque gradient is corrected and affects the vehicle smoothness, in the follow-up control mode, it is detected whether the duration that the fluctuation amplitude of the current accelerator pedal change rate is less than the target fluctuation amplitude reaches a target duration, that is, whether the current accelerator pedal change rate is basically unchanged within the target duration T, and if so, the correction coefficient is lowered: ; the correction coefficient is gradually lowered to 0 within the target duration, and the target torque gradient in the follow-up control mode is updated based on the current gradient correction coefficient after being lowered. When the current gradient correction coefficient after being lowered is equal to 0, the target torque gradient in the follow-up control mode is the smaller one of the engine maximum torque gradient and the engine economic interval torque gradient, further improving the stability and economy of vehicle driving.

[0060] In an embodiment, the application further provides a torque determination method, which further comprises the following step S71: Step S71: maintaining the current torque control mode of the engine as the target control mode in the case that the driving torque of the driving motor is not limited and the charge-discharge power of the battery pack is not limited.

[0061] In the embodiment, when the vehicle enters the parallel mode, it is determined that the current torque control mode of the engine is the target control mode, and the current torque control mode of the engine is maintained as the target control mode in the case that the driving torque of the driving motor is not limited and the charge-discharge power of the battery pack is not limited. In addition, after the current torque control mode of the vehicle is switched from the target control mode to the follow-up control mode, the current torque control mode can be switched from the follow-up control mode to the target control mode after the case that the driving torque of the driving motor is limited or the charge-discharge power of the battery pack is limited is solved. Thus, in the normal working condition of the vehicle in the parallel mode, the generator is controlled in the optimal working interval through the target control mode, ensuring the continuity of fuel economy optimization, so as to improve the economy of the vehicle.

[0062] In an embodiment, the application further provides a torque determination method, which further comprises the following steps S81-S83: Step S81: detecting whether the vehicle enters a coasting state according to the driver demand torque, the accelerator pedal state and the actual speed of the engine in the case that the driving torque of the driving motor is not limited and the charge-discharge power of the battery pack is not limited; Step S82: sending a fuel cut control instruction to the engine in the case that the vehicle enters the coasting state, and determining the first target torque as a friction torque; Step S83: After the vehicle exits the coasting state, determine the first target torque of the engine based on the driver's required torque and the universal characteristic curve of the engine.

[0063] In this embodiment, when there is no limitation on the drive motor's driving torque or the battery pack's charging and discharging power, i.e., the vehicle's current torque control mode remains the target control mode, the system detects whether the vehicle has entered a coasting state based on the driver's required torque, the accelerator pedal position, and the engine's actual speed. When the driver's required torque is less than zero, the accelerator pedal is not depressed, and the engine speed is greater than a first threshold (e.g., 1300 rpm), the vehicle enters a coasting state. At this time, to prevent frequent shifts between series and parallel modes, a fuel cut-off control command is sent to the engine, requesting fuel cut-off control. The first target torque is determined to be equal to the friction torque, further improving the vehicle's fuel economy. Here, friction torque refers to the internal friction torque of the engine (i.e., the mechanical resistance torque of the engine itself during operation). When the vehicle exits the coasting state, i.e., the driver's required torque is again greater than a second threshold (e.g., 3 Nm), and the accelerator pedal is depressed (e.g., accelerator pedal opening greater than 2%), the engine is controlled to inject fuel to achieve torque output. The current torque control mode is the target control mode, and the engine's first target torque is determined based on the driver's required torque and the engine's universal characteristic curve.

[0064] In one embodiment, such as Figure 3 As shown, Figure 3 This is a flowchart illustrating the overall steps of a torque determination method according to an embodiment of this application. First, vehicle signals are acquired and analyzed to obtain the actual engine speed, driver-demanded torque, target SOC, etc. Then, the engine's basic torque request is calculated and corrected. Based on the driver-demanded torque and the actual engine speed, the engine's basic torque request is calculated and corrected based on the ΔSOC under the current hybrid powertrain strategy, yielding the first target torque under the target control mode. Next, an engine torque following activation judgment is performed: when the drive motor's driving torque is limited and / or the battery pack's charging / discharging power is limited, engine torque following is activated, and engine torque following control (following control mode) is implemented: engine torque request = driver-demanded torque. When the drive motor's driving torque is limited and the battery pack's charging / discharging power is not limited, an engine fuel cut-off control judgment is performed. If engine fuel cut-off control is required, the engine torque (first target torque) equals the friction torque. If engine fuel cut-off control is not required, the engine's basic torque request is calculated and corrected to obtain the first target torque under the target control mode.

[0065] Based on the same inventive concept, one embodiment of this application provides a torque determining device. Figure 4 This is a schematic diagram of the structure of a torque determining device provided in an embodiment of this application, as shown below. Figure 4As shown, the device comprises: The first determining module is configured to determine that the current torque control mode of the engine is the target control mode when the vehicle is in the parallel mode. The second determining module is configured to determine the first target torque of the engine based on the driver demand torque and the engine characteristic curve when in the target control mode. The switching module is configured to switch the current torque control mode of the engine from the target control mode to the follow-up control mode when the drive torque of the drive motor is limited and / or the charge-discharge power of the battery pack is limited. The third determining module is configured to determine the second target torque of the engine based on the driver demand torque when in the follow-up control mode.

[0066] In an optional embodiment, the second determining module comprises: The first calculating module is configured to obtain the basic torque of the engine operating in the optimal fuel economy interval according to the actual speed of the engine, the driver demand torque, and the engine characteristic curve. The second calculating module is configured to obtain the current remaining power difference according to the actual remaining power and the current target remaining power of the vehicle, the current target remaining power being associated with the current oil-electricity use strategy of the vehicle in the parallel mode. The first querying module is configured to query the corresponding relationship among the remaining power difference, the oil-electricity use strategy, and the torque correction coefficient according to the current remaining power difference and the current oil-electricity use strategy, and obtain the current torque correction coefficient. The first correcting module is configured to correct the basic torque according to the current torque correction coefficient and the upper and lower limits of the engine economy interval torque of the actual speed of the engine, and obtain the first target torque.

[0067] In an optional embodiment, the third determining module comprises: The third calculating module is configured to determine the smaller one of the driver demand torque and the engine torque limit value as the second target torque.

[0068] In an optional embodiment, the device further comprises: The second querying module is configured to query the corresponding relationship among the current accelerator pedal change rate, the current vehicle speed, and the gradient correction coefficient according to the current accelerator pedal change rate and the current vehicle speed, and obtain the current gradient correction coefficient. The second correcting module is configured to obtain the target torque gradient in the follow-up control mode according to the maximum engine torque gradient, the engine economy interval torque gradient, and the current gradient correction coefficient.

[0069] In an optional implementation, the apparatus further includes: The first detection module is configured to, in the follow-up control mode, detect whether a duration, during which the fluctuation amplitude of the current accelerator pedal change rate is less than the target fluctuation amplitude, reaches a target duration. The adjustment module is configured to, in a case where the duration reaches the target duration, gradually reduce the current gradient correction coefficient to zero within the target duration. The update module is configured to update the target torque gradient in the follow-up control mode based on the reduced current gradient correction coefficient. In a case where the reduced current gradient correction coefficient is equal to zero, the target torque gradient in the follow-up control mode is the smaller one of the maximum engine torque gradient and the engine economic interval torque gradient.

[0070] In an optional implementation, the apparatus further includes: The fourth determination module is configured to, in a case where the drive torque of the drive motor is not limited and the charge-discharge power of the battery pack is not limited, maintain the current torque control mode of the engine as the target control mode.

[0071] In an optional implementation, the apparatus further includes: The second detection module is configured to, in a case where the drive torque of the drive motor is not limited and the charge-discharge power of the battery pack is not limited, detect whether the vehicle enters a coasting state according to the driver demand torque, the accelerator pedal state, and the actual speed of the engine. The processing module is configured to, in a case where the vehicle enters the coasting state, send a fuel cut-off control instruction to the engine, and determine the first target torque as a friction torque. The fifth determination module is configured to, after the vehicle exits the coasting state, determine the first target torque of the engine based on the driver demand torque and the universal characteristic curve of the engine.

[0072] Based on the same inventive concept, an embodiment of the present application provides an electronic device, which refers to Figure 5 , Figure 5 is a schematic diagram of an electronic device according to an embodiment of the present application. As shown in Figure 5 The electronic device 100 includes a memory 110 and a processor 120, the memory 110 and the processor 120 are communicatively connected through a bus, and the memory 110 stores a computer program which can run on the processor 120, thereby implementing the steps in the torque determination method according to any of the above embodiments of the present application.

[0073] Based on the same inventive concept, the embodiments of the present disclosure further provide a computer-readable storage medium, when instructions in the computer-readable storage medium are executed by a processor of a computer device, the computer device is enabled to perform the steps in the torque determination method according to any one of the embodiments of the present application.

[0074] Based on the same inventive concept, the embodiments of the present application further provide a vehicle, comprising: an engine, a generator, a drive motor and a vehicle controller, the vehicle controller is capable of performing the steps in the torque determination method according to any one of the embodiments of the present application.

[0075] Based on the same inventive concept, the embodiments of the present disclosure further provide a computer program product, comprising a computer program, when the computer program is executed by a processor of a computer device, the computer program is capable of performing the steps in the torque determination method according to any one of the embodiments of the present application.

[0076] Each of the embodiments in the present specification is described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between the embodiments can be referred to each other.

[0077] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, device or computer program product. Therefore, the embodiments of the present application can be in the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Moreover, the embodiments of the present application can be in the form of a computer program product implemented on one or more computer usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

[0078] The embodiments of the present application are described with reference to flowcharts and / or block diagrams according to the method, terminal device (system) and computer program product of the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be realized by computer program instructions. These computer program instructions can be provided to a general purpose computer, a special purpose computer, an embedded processor or other programmable data processing terminal device to produce a machine, so that the instructions executed by the computer or other programmable data processing terminal device produce a device for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 The device for implementing the functions specified in one flow or multiple flows and / or blocks Figure 1 The device for implementing the functions specified in one flow or multiple flows and / or blocks

[0079] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the flow Figure 1 one or more flow or block Figure 1 one or more blocks or blocks specified in the flow.

[0080] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the flow Figure 1 one or more flow or block Figure 1 one or more blocks or blocks specified in the flow.

[0081] Although preferred embodiments of the application have been described, those skilled in the art will recognize that additional modifications and changes can be made thereto without departing from the scope of the application. Accordingly, the appended claims are intended to cover all such modifications and changes as fall within the scope of the application.

[0082] Finally, it should be noted that the terms "first", "second", and the like, herein do not denote any order, quantity, combination, or importance, but rather are used to distinguish one element from another, and are not intended to denote a particular order, quantity, combination, or importance of, or between, the elements so designated. Also, the use of the terms "including", "containing", or "comprising" and variations thereof, is meant to encompass the inclusion of zero or more elements, steps, or components, and is not meant to exclude the addition of other elements, steps, or components, or the performance of further steps, unless otherwise indicated or inferred by context. The use of the term "comprising" is not intended to exclude the addition of further elements, steps, or components, or the performance of further steps, to those described herein.

[0083] The above provides a torque determination method, device, storage medium and vehicle, and the principle and implementation manner of the application are described by using specific examples. The above description of the embodiments is only used to help understand the method and core idea of the application. Meanwhile, for those skilled in the art, according to the idea of the application, the specific implementation manner and application range can be changed, and the above description of the application should not be understood as a limitation.

Claims

1. A torque determination method characterized by, The method comprises: In the case that the vehicle is in parallel mode, determining that the current torque control mode of the engine is a target control mode; In the target control mode, determining a first target torque of the engine based on a driver demand torque and a universal characteristic curve of the engine; In the case that driving torque of the driving motor is limited and / or charging and discharging power of the battery pack is limited, switching the current torque control mode of the engine from the target control mode to a follow-up control mode; In the follow-up control mode, determining a second target torque of the engine based on the driver demand torque.

2. The torque determination method according to claim 1, characterized in that, In the target control mode, determining a first target torque of the engine based on a driver demand torque and a universal characteristic curve of the engine, comprises: obtaining a basic torque in which the engine works in an optimal fuel economy interval according to an actual speed of the engine, the driver demand torque and the universal characteristic curve of the engine; obtaining a current residual power difference value according to an actual residual power of the vehicle and a current target residual power, the current target residual power being associated with a current oil-electricity use strategy of the vehicle in parallel mode; obtaining a current torque correction coefficient by querying a corresponding relationship among residual power difference values, oil-electricity use strategies and torque correction coefficients according to the current residual power difference value and the current oil-electricity use strategy; correcting the basic torque according to the current torque correction coefficient and an upper limit and a lower limit of engine economy interval torque in which the actual speed of the engine is located, to obtain the first target torque.

3. The torque determination method according to claim 1, characterized in that, In the follow-up control mode, determining a second target torque of the engine based on the driver demand torque, comprises: determining the smaller one of the driver demand torque and an engine torque limit value as the second target torque.

4. The torque determination method according to claim 1, characterized by, The method further comprises: obtaining a current gradient correction coefficient by querying a corresponding relationship among accelerator pedal change rates, vehicle speeds and gradient correction coefficients according to a current accelerator pedal change rate and a current vehicle speed; obtaining a target torque gradient in the follow-up control mode according to a maximum engine torque gradient, an engine economy interval torque gradient and the current gradient correction coefficient.

5. The torque determination method according to claim 4, characterized by, After obtaining the target torque gradient in the follow-up control mode, the method further comprises: detecting whether a duration in which the fluctuation amplitude of the current accelerator pedal change rate is less than a target fluctuation amplitude reaches a target duration in the follow-up control mode; gradually lowering the current gradient correction coefficient to zero within the target duration in the case that the duration reaches the target duration; updating the target torque gradient in the follow-up control mode based on the lowered current gradient correction coefficient; wherein, in the case that the lowered current gradient correction coefficient is equal to zero, the target torque gradient in the follow-up control mode is the smaller one of the maximum engine torque gradient and the engine economy interval torque gradient.

6. The torque determination method according to claim 1, characterized by, The method further comprises: In a case where the driving torque of the driving motor is not limited and the charge-discharge power of the battery pack is not limited, the current torque control mode of the engine is kept as the target control mode.

7. The torque determination method according to claim 6, characterized in that, The method further comprises: In a case where the driving torque of the driving motor is not limited and the charge-discharge power of the battery pack is not limited, it is detected whether the vehicle enters a coasting state according to the driver demand torque, the accelerator pedal state and the actual speed of the engine; In a case where the vehicle enters the coasting state, a fuel cut control instruction is sent to the engine, and the first target torque is determined as a friction torque; After the vehicle exits the coasting state, the first target torque of the engine is determined based on the driver demand torque and the universal characteristic curve of the engine.

8. A torque determination device, characterized by The device comprises: A first determining module configured to determine, in a case where the vehicle is in a parallel mode, that the current torque control mode of the engine is a target control mode; A second determining module configured to determine, in the target control mode, the first target torque of the engine based on the driver demand torque and the universal characteristic curve of the engine; A switching module configured to switch, in a case where the driving torque of the driving motor is limited and / or the charge-discharge power of the battery pack is limited, the current torque control mode of the engine from the target control mode to a follow-up control mode; A third determining module configured to determine, in the follow-up control mode, the second target torque of the engine based on the driver demand torque.

9. An electronic device, comprising: A processor, a memory and a computer program stored on the memory and executable on the processor, the processor implementing the torque determination method of any one of claims 1 to 7 when executing the computer program. An engine, a generator, a driving motor and a vehicle controller, the vehicle controller being configured to implement the torque determination method of any one of claims 1 to 7.

10. A vehicle comprising: An engine, a generator, a driving motor and a vehicle controller, the vehicle controller being configured to implement the torque determination method of any one of claims 1 to 7.

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