Hybrid vehicle, engine starting control method thereof, medium, and controller

Abstract

A hybrid vehicle, an engine starting control method thereof, a medium, and a controller, relating to the technical field of hybrid vehicles. The method comprises: after satisfying an engine starting condition, acquiring the engine oil temperature and the cooling liquid temperature of the engine; according to the engine oil temperature and the cooling liquid temperature, looking up in a preset corresponding relationship to obtain the working loss torque of the engine; and, according to the working loss torque, controlling an ISG motor of a hybrid vehicle so as to start the engine.

Description

Hybrid vehicle and engine start control method, medium, and controller thereof

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese patent application number 202211504126.3, filed on November 28, 2022, entitled “Hybrid vehicle, engine start control method thereof, medium, and controller,” the entire contents of which are incorporated by reference into this disclosure. Technical Field

[0003] The present disclosure relates to the technical field of hybrid vehicles, and in particular to a hybrid vehicle and an engine start control method, medium, and controller thereof. Background Art

[0004] In hybrid vehicles, the engine's participation in power generation involves operating conditions such as engine starting, power generation, and shutdown. This requires collaboration between the engine and the integrated starter generator (ISG) motor. This collaborative process involves torque control, and under actual operating conditions, the engine experiences torque loss. In related technologies, the engine torque loss used can differ significantly from the actual torque loss, resulting in inaccurate engine starting control and affecting the smooth operation of the ISG motor.

[0005] Summary of the Invention

[0006] The purpose of the present disclosure is to provide a hybrid vehicle and its engine starting control method, medium, and controller to improve the accuracy of engine starting control and ensure the smooth operation of the ISG motor.

[0007] In a first aspect, the present disclosure proposes an engine starting control method for a hybrid vehicle, the method comprising: obtaining the engine oil temperature and coolant temperature after the engine starting conditions are met; searching for a preset corresponding relationship based on the oil temperature and the coolant temperature to obtain the working loss torque of the engine; and controlling the ISG motor of the hybrid vehicle based on the working loss torque to start the engine.

[0008] In a second aspect, the present disclosure proposes a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the above-mentioned engine start control method of a hybrid vehicle is implemented.

[0009] In a third aspect, the present disclosure proposes a controller, characterized in that it includes a memory, a processor, and a computer program stored in the memory, and when the computer program is executed by the processor, it implements the above-mentioned hybrid vehicle engine start control method.

[0010] In a fourth aspect, the present disclosure proposes a hybrid vehicle, characterized in that it includes: an engine, an ISG motor and the above-mentioned controller.

[0011] The hybrid vehicle and its engine starting control method, medium, and controller of the disclosed embodiment, during engine starting control, obtain the engine loss torque according to the engine coolant temperature and oil temperature by looking up the table, and inversely calculate the working torque of the ISG motor (i.e., the target torque) through the torque balance formula to perform engine starting control, so that the engine loss torque used in the engine starting control process is more accurate, the ISG motor torque control is more precise, the ISG motor and the engine work together better, and the engine speed change quality is improved.

[0012] Additional aspects and advantages of the present disclosure will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG1 is a schematic diagram of a power frame of a hybrid vehicle according to an embodiment of the present disclosure;

[0014] FIG2 is a schematic diagram showing engine start control performance of a hybrid vehicle in the related art;

[0015] FIG3 is a flow chart of an engine start control method for a hybrid vehicle according to an embodiment of the present disclosure;

[0016] FIG4 is a flow chart of an engine start control method for a hybrid vehicle according to another embodiment of the present disclosure;

[0017] FIG5 is a flow chart of calculation of combustion torque according to one embodiment of the present disclosure;

[0018] FIG6 is a flowchart of calculating the rotational torque according to an embodiment of the present disclosure;

[0019] FIG7 is a flowchart of torque loss correction according to an embodiment of the present disclosure;

[0020] FIG8 is a schematic diagram illustrating engine start control performance of a hybrid vehicle according to the present disclosure;

[0021] FIG9 is a structural block diagram of a controller according to an embodiment of the present disclosure;

[0022] FIG10 is a structural block diagram of a hybrid vehicle according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0023] The following describes in detail embodiments of the present disclosure, examples of which 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 disclosure, and should not be construed as limiting the present disclosure.

[0024] In the present disclosure, the power architecture of a hybrid vehicle is shown in FIG1 , and is composed of an integrated starter and generator motor (ISG motor), an engine (ENG), a clutch (C), a power battery (Battery), and drive motors (M1 and M2). The connection to the power battery is a high-voltage cable connection, and the other connections are mechanical connections. W represents the wheels of the hybrid vehicle. When the engine needs to start running, the ISG motor drags the engine to rotate. At this time, the ISG motor is the power source and the engine is the load. When the engine needs to replenish electrical energy for the power battery, the running engine drives the ISG motor to rotate, and the ISG motor generates electricity to replenish electrical energy for the power battery. At this time, the engine is the power source and the ISG motor is the load. When the engine needs to directly participate in driving, the clutch is engaged, and the engine directly transmits power to the wheel end.

[0025] In related technologies, regardless of ambient temperature, the ISG motor uses the same loss torque when starting the engine. This results in inaccurate engine loss torque, and the ISG motor loads and unloads torque at a fixed slope. This causes an uneven speed transition during startup, which can also lead to problems such as jitter and abnormal noise, resulting in poor startup quality. Analysis of the marked points in Figure 2 shows that related technologies have at least the following six problems during startup:

[0026] ① The ISG motor's drag torque is too large, the engine speed and ISG motor synchronization time is long, and the torsional damper has a large workload, which may cause problems such as abnormal noise when starting;

[0027] ②The engine loss torque is inaccurate and the engine torque control accuracy is not high;

[0028] ③ The engine speed has a drop, and the speed fluctuation will cause vibration;

[0029] ④ The engine's overshoot speed is too high, usually about 300 rpm higher than the idle speed;

[0030] ⑤The unloading torque slope of the ISG motor is fixed, usually a fixed value, and cannot adapt to various ambient temperatures;

[0031] ⑥The ISG motor torque is not completely unloaded, and the force on the drive shaft is uneven, resulting in a secondary overshoot in the speed.

[0032] To this end, the present disclosure proposes a hybrid vehicle, an engine start control method, a medium, and a controller therefor. These methods utilize different loss torques at different ambient temperatures to control the ISG motor to start the engine, thereby improving the accuracy of engine start control and ensuring smooth operation of the ISG motor. The hybrid vehicle, an engine start control method, a medium, and a controller therefor, according to embodiments of the present disclosure, are described below with reference to the accompanying drawings.

[0033] FIG3 is a flow chart of an engine start control method for a hybrid vehicle according to an embodiment of the present disclosure. As shown in FIG3 , the engine start control method includes:

[0034] S31: After the engine start condition is met, the engine oil temperature and coolant temperature are obtained.

[0035] The engine start condition may be that the hybrid vehicle starts an HEV (Hybrid Electric Vehicle) mode, or that the hybrid vehicle needs to be charged.

[0036] In some examples, a HEV switch button is provided in the hybrid vehicle. When the user presses the button, the vehicle controller of the hybrid vehicle obtains a hybrid electric vehicle mode switch instruction. At this time, it can be determined that the hybrid vehicle currently meets the engine start conditions.

[0037] In other examples, when the current remaining power of the power battery in the hybrid vehicle is less than a first power threshold, it is determined that the engine start condition is currently met. The first power threshold can be preset, for example, 10%.

[0038] In some other examples, if the hybrid vehicle is in a parked state, it is determined that the engine start conditions are currently met when it is monitored that the accelerator pedal depth of the hybrid vehicle is greater than the opening threshold and the remaining power of the power battery is less than the second power threshold and greater than the first power threshold.

[0039] S32: According to the engine oil temperature and the coolant temperature, a preset corresponding relationship is searched to obtain the engine's working loss torque.

[0040] Specifically, when the engine start conditions are met, the ISG motor and the engine need to cooperate to achieve engine start. In order to ensure the accuracy of the engine loss torque (including pumping loss, ventilation loss, accessory friction loss, etc.) during engine start control, the present disclosure takes into account that at different oil temperatures and different coolant temperatures, the oil viscosity is different and the engine's own friction is also different, resulting in different engine loss torque, and establishes a correspondence between the engine's oil temperature, coolant temperature and loss torque (i.e., the above-mentioned preset correspondence, which can be stored in a table). Then, when the engine start conditions are met, the engine's oil temperature and coolant temperature are first obtained, and then the preset correspondence is searched to obtain the corresponding loss torque (i.e., the above-mentioned engine working loss torque). Among them, the oil temperature and coolant temperature can be detected by setting corresponding temperature sensors.

[0041] S33: Control the ISG motor of the hybrid vehicle according to the working loss torque to start the engine.

[0042] Specifically, after obtaining the working loss torque of the engine, the target torque of the ISG motor can be obtained based on the working loss torque (for example, a correspondence between the loss torque and the target torque can be established, and then the target torque of the ISG motor can be obtained by searching the correspondence based on the working loss torque). Then, the ISG motor can be loaded and unloaded according to the target torque. Among them, the loading control can be to control the ISG motor to load the torque to the target torque and drag the engine to rotate with the target torque; the unloading control can be to control the ISG motor to unload the torque when the engine speed reaches the speed threshold N1. It should be noted that while controlling the ISG motor to unload the torque, the engine fuel injection and ignition are controlled. When the engine speed reaches the speed threshold N2, the EMS (Engine Management System) determines that the engine start is complete. Thereafter, the engine transitions to the VCU (Vehicle Control Unit) target torque control in response to the VCU target torque.

[0043] The engine starting control method of a hybrid vehicle in an embodiment of the present disclosure first obtains the engine oil temperature and coolant temperature when the engine starting conditions are met, and then searches for a preset corresponding relationship to obtain the engine's working loss torque. Based on the working loss torque, the ISG motor is controlled to achieve engine starting, which can improve the accuracy of engine starting control and ensure the smooth operation of the ISG motor.

[0044] In some embodiments of the present disclosure, as shown in FIG4 , the engine start control method further includes:

[0045] S41, during the engine startup process, obtaining the engine crank angle and crankshaft angular velocity.

[0046] Specifically, as shown in Figure 5, a sampling frequency identical to the engine speed sampling frequency can be used. During engine startup, the crankshaft position sensor can be used to obtain the crankshaft position at that moment. The engine crank angle α can then be derived from this crankshaft position. Crank angle α is the crank angle corresponding to the engine cylinder undergoing expansion and power generation, ranging from 0-180°. It represents the crankshaft angle during the expansion and power generation stroke. Simultaneously, as shown in Figure 6, an angular velocity sensor can be used to obtain the crankshaft angular velocity, using the same sampling frequency as the engine speed sampling frequency.

[0047] S42: Obtain the combustion torque generated by the combustion gas in the engine cylinder on the engine crankshaft according to the crank angle, and obtain the rotational torque of the transmission shaft according to the crankshaft angular velocity.

[0048] In some examples, combustion torque is given by: 燃烧 =p i ×s×cosβ×r×sin(α+β),

[0049] Among them, T 燃烧 is the combustion torque, β=arcsin(r×sinα÷l), is the crankshaft connecting rod swing angle, l is the crankshaft connecting rod length, r is the crank radius, s is the surface area of ​​the piston head in the cylinder, α is the crank angle, p i is the combustion explosion pressure in the cylinder.

[0050] Specifically, referring to FIG5 , for a hybrid vehicle engine, the crankshaft connecting rod length l, crank radius r, and piston head surface area s are constant values, and the corresponding relationship between the crankshaft connecting rod swing angle β and the crank angle α satisfies β = arcsin (r × sin α ÷ l), that is, the crankshaft connecting rod swing angle β and the crank angle α have a one-to-one correspondence. Under the conditions of crankshaft connecting rod length l, crank radius r, piston head surface area s, connecting rod swing angle β, crank angle α, and combustion explosion pressure p in the cylinder, the crankshaft connecting rod swing angle β and the crank angle α are constant values. i When all are known, the combustion torque T generated by the high-temperature and high-pressure combustion gas in the cylinder on the crankshaft can be obtained by analyzing the force on the piston crankshaft. 燃烧 =p i ×s×cosβ×r×sin(α+β).

[0051] In some examples, the rotational torque is given by: 转矩 =J×a i ,

[0052] Among them, T 转矩 is the rotational torque, J is the moment of inertia of the transmission shaft, a i =(w i -w i-1) / t, is the crankshaft angular acceleration at the i-th moment, w i is the crankshaft angular velocity at the i-th moment, and t is the time difference between the i-th moment and the i-1-th moment.

[0053] Specifically, when the engine speed is non-uniform, rotational acceleration generates torque on the engine and the entire drive shaft. Referring to Figure 6 , the moment of inertia of the engine crankshaft, flywheel, torsional vibration damper, and rotating components connected to the ISG can be integrated and accumulated. It should be noted that for a given ISG motor and engine combination, the moment of inertia J is a fixed value that can be pre-stored and directly read when needed.

[0054] The crankshaft angular velocity w at the current sampling moment is collected i and the crankshaft angular velocity w at the previous sampling moment i-1 After that, according to the formula (w i -w i-1 ) / tCalculate the angular acceleration a at this moment i , and then according to the formula J×a i Get the rotational torque T of the transmission shaft at time i 转矩 .

[0055] S43, obtaining the initial torque of the ISG motor, and obtaining the actual loss torque of the engine at the oil temperature and the coolant temperature according to the combustion torque, the rotation torque and the initial torque.

[0056] In some examples, the actual loss torque of the engine at oil temperature and coolant temperature is obtained based on the combustion torque, rotational torque and initial torque, which may include: calculating the difference between the combustion torque and the rotational torque, and calculating the sum of the difference and the initial torque, and using the sum as the actual loss torque.

[0057] Specifically, as shown in FIG7 , torque analysis of the transmission shaft shows that at any time, there is a force balance T 燃烧 +T ISG =T 损失 +T 转矩 , where T ISG It is a positive torque when the engine starts and a negative torque when the engine participates in power generation. When the engine rotates at a constant speed, T 转矩 is 0, T 燃烧 +T ISG =T 损失 ; When the engine rotates at a non-uniform speed, T 转矩 Not 0, T 燃烧 +T ISG =T 损失 +T 转矩 .

[0058] Referring to Figure 7, the equation T燃烧 +T ISG =T 损失 +T 转矩 Transformation can be obtained T 损失 =T 燃烧 +T ISG -T 转矩 , where T 燃烧 、T 转 矩 and T ISG When all are known, the actual loss torque T of the engine 损失 According to the formula T 损失 =T 燃烧 +T ISG -T 转矩 Calculated.

[0059] It should be noted that the initial torque of the ISG motor used to calculate the actual loss torque is a constant value, which can be the target torque of the ISG motor used when the hybrid vehicle starts the engine for the first time after leaving the factory, and is a factory-set value. During the engine start control process of the hybrid vehicle, the actual loss torque can be continuously calculated based on the combustion torque and the rotation torque to obtain a stable difference between the combustion torque and the rotation torque, and then according to the formula T 损失 =T 燃烧 +T ISG -T 转矩 Get a stable T 损 失 .

[0060] S44: updating the preset corresponding relationship according to the actual torque loss.

[0061] Specifically, in actual engineering applications, engine torque loss is interpolated from a preset table stored in the EMS chip. This torque loss table is typically measured on an engine test bench using the cylinder-killing method, the fuel consumption line method, or the reverse drag method. Most gasoline engines use the reverse drag method for measurement. Because the reverse drag method typically measures engine torque loss at engine coolant temperatures of 85°C or above and engine oil temperatures of 85°C or above, the engine torque loss measured by the reverse drag method does not take into account the rotational torque of the drive shaft. It also does not account for differences in engine torque loss at different engine coolant and oil temperatures. This results in a significant discrepancy between the engine torque loss obtained from the table and the actual torque loss under actual vehicle operating conditions.

[0062] From the above formula T 损失 =T 燃烧 +T ISG -T 转矩The actual loss torque value of the engine at any time during the actual use of the vehicle can be obtained. At the same time, considering that the oil viscosity and the engine friction are different at different oil temperatures and engine coolant temperatures, the loss torque of the engine is also different. Therefore, the engine loss torque T at each oil temperature and each engine coolant temperature is calculated. 损失-t It is very necessary to calculate it.

[0063] 7, the present disclosure records the oil temperature, the engine coolant temperature, and the formula T in each engine start control. 损失 =T 燃烧 +T ISG -T 转矩 Calculate the engine loss torque T 损失-t , and the T 损失-t As the engine loss torque measured by the reverse drag method, the self-learning value based on environmental adaptability is used to update the preset correspondence between the current oil temperature, engine coolant and loss torque. In the actual use of the vehicle afterwards, if the engine is at a certain oil temperature or a certain engine coolant temperature, the EMS will look up the table to obtain the corresponding T 损失-t This is sent to the vehicle bus and other controllers as engine loss torque. The update can be as follows: if the currently recorded oil temperature or engine coolant temperature does not exist in the current preset correspondence, the oil temperature, engine coolant temperature, and their corresponding actual loss torque are directly added to the current preset correspondence; if the currently recorded oil temperature, engine coolant temperature, and their corresponding actual loss torque do exist in the current preset correspondence, the oil temperature, engine coolant temperature, and their corresponding actual loss torque replace the oil temperature, engine coolant temperature, and their corresponding actual loss torque in the current preset correspondence. This ensures the accuracy of the engine loss torque used by hybrid vehicles.

[0064] In some embodiments, controlling the ISG motor of a hybrid vehicle based on the working loss torque may include: obtaining a target torque of the ISG motor based on the working loss torque, the rotational torque, and the combustion torque; and performing loading control and unloading control on the ISG motor based on the target torque.

[0065] Specifically, the engine loss torque T 损失-t After being sent to the vehicle bus, the ISG motor can be ISG '=T 损失-t +T 转矩 -T 燃烧 To determine the target torque of the ISG motor to perform loading control and unloading control of the ISG motor.

[0066] In some embodiments, the engine start control method also includes: judging whether the engine is in a uniform rotation process based on the crankshaft angular velocity; if the engine is in a uniform rotation process, adjusting the engine's fuel injection, ignition and intake to make the ISG motor work smoothly; if the engine is in a non-uniform rotation process, determining the loading slope and unloading slope of the ISG motor based on the change in the rotational torque, and controlling the loading of the ISG motor based on the loading slope, and controlling the unloading of the ISG motor based on the unloading slope.

[0067] Specifically, during the engine's uniform rotation, T 转矩 When the engine is 0, the engine fuel injection, ignition and air intake can be adjusted to achieve further steady-state operation, making the ISG motor work smoothly and reducing the load impact caused by voltage and current fluctuations. 转矩 If the value is not zero, the loading and unloading slopes of the ISG motor can be determined by the dynamic changes in the transmission shaft torque, thereby enabling the ISG motor and engine to work more effectively together and improving the quality of the engine's speed change process. The loading and unloading slopes of the ISG motor can be determined by the dynamic changes in the transmission shaft torque: during the loading process, when the torque is 0, the loading slope is constant, and when the torque is greater than 0, the loading slope decreases; during the unloading process, when the torque is 0, the unloading slope is constant, and when the torque is greater than 0, the unloading slope increases.

[0068] As shown in Figure 8, after adjusting the ISG motor's unloading torque using the disclosed method, the engine speed rises smoothly at position ①, the engine torque loss is accurate at position ②, the engine speed does not drop at position ③, and the engine's overshoot speed is controlled within 150 rpm at position ④. The ISG motor and engine work together well, improving starting quality.

[0069] Based on the above-mentioned engine start control method for a hybrid vehicle, the present disclosure further proposes a computer-readable storage medium.

[0070] In this embodiment, a computer program is stored on a computer-readable storage medium. When the computer program is executed by a processor, the above-mentioned engine start control method for a hybrid vehicle is implemented.

[0071] The present disclosure also provides a controller.

[0072] FIG9 is a structural block diagram of a controller according to an embodiment of the present disclosure.

[0073] As shown in Figure 9, controller 900 includes a processor 901 and a memory 903. Processor 901 and memory 903 are connected, for example, via a bus 902. Optionally, controller 900 may also include a transceiver 904. It should be noted that in practical applications, the number of transceivers 904 is not limited to one, and the structure of controller 900 does not constitute a limitation on the embodiments of the present disclosure.

[0074] The processor 901 may be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It may implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the present disclosure. The processor 901 may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and the like.

[0075] Bus 902 may include a path for transmitting information between the aforementioned components. Bus 902 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, for example. Bus 902 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, FIG5 shows only one thick line, but this does not indicate that there is only one bus or only one type of bus.

[0076] Memory 903 is used to store a computer program corresponding to the engine start control method for a hybrid vehicle according to the above-mentioned embodiment of the present disclosure, and the computer program is controlled and executed by processor 901. Processor 901 is used to execute the computer program stored in memory 903 to implement the contents of the above-mentioned method embodiment.

[0077] It should be noted that the controller 900 shown in FIG9 is merely an example and should not impose any limitations on the functions and scope of use of the embodiments of the present disclosure.

[0078] The present disclosure also proposes a hybrid vehicle.

[0079] FIG10 is a block diagram of the hybrid vehicle of the present disclosure.

[0080] As shown in FIG. 10 , a hybrid vehicle 1000 includes an engine 100 , an ISG motor 200 , and the controller 900 of the above embodiment.

[0081] In summary, the hybrid vehicle and its engine starting control method, medium, and controller of the disclosed embodiment calculate the actual loss torque during the engine rotation process through the initial torque of the ISG motor, the combustion torque of the engine, and the rotational torque of the transmission shaft; at the same time, the engine coolant temperature and oil temperature under the working condition are obtained, and the temperature and the corresponding actual loss torque are used as self-learning values ​​based on environmental adaptability to update the preset correspondence stored in the EMS; and then in the subsequent (next or next few) engine starting control, the engine loss torque is obtained by looking up the table based on the engine coolant temperature and oil temperature, and the working torque of the ISG motor (i.e., the target torque) is calculated by reverse calculation through the torque balance formula to perform engine starting control. As a result, the engine loss torque used in the engine starting control process is more accurate, the ISG motor torque control is more precise, the ISG motor and the engine work better together, and the engine speed change quality is improved.

[0082] It should be noted that the logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device), or in conjunction with such instruction execution system, apparatus, or device. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transmit a program for use by an instruction execution system, apparatus, or device, or in conjunction with such instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection portion having one or more wires (electronic device), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable compact disc read-only memory (CDROM). Furthermore, 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, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0083] It should be understood that various parts of the present disclosure can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0084] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0085] In the description of the present disclosure, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present disclosure.

[0086] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. Throughout the present disclosure, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0087] In this disclosure, unless otherwise expressly specified or limited, terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components, unless otherwise expressly limited. Those skilled in the art will understand the specific meanings of the above terms in this disclosure based on specific circumstances.

[0088] In the present disclosure, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0089] Although the embodiments of the present disclosure have been shown and described above, it is understood that the above embodiments are illustrative and are not to be construed as limitations on the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

Claims

1. An engine starting control method for a hybrid vehicle, characterized in that, the method includes: After the engine starting condition is satisfied, obtain the engine oil temperature and coolant temperature; According to the engine oil temperature and the coolant temperature, look up the preset corresponding relationship to obtain the working loss torque of the engine; Control the ISG motor of the hybrid vehicle according to the working loss torque to realize the starting of the engine.

2. The engine starting control method for a hybrid vehicle according to claim 1, characterized in that, the method further includes: During the engine starting process, obtain the crank angle and crankshaft angular velocity of the engine; Obtain the combustion torque generated by the combustion gas in the engine cylinder on the engine crankshaft according to the crank angle, and obtain the rotational torque of the transmission shaft according to the crankshaft angular velocity; Obtain the initial torque of the ISG motor, and according to the combustion torque, the rotational torque and the initial torque, obtain the actual loss torque of the engine at the engine oil temperature and the coolant temperature; Update the preset corresponding relationship according to the actual loss torque.

3. The engine starting control method for a hybrid vehicle according to claim 2, characterized in that, The obtaining the actual loss torque of the engine at the engine oil temperature and the coolant temperature according to the combustion torque, the rotational torque and the initial torque includes: Calculate the difference between the combustion torque and the rotational torque, calculate the sum of the difference and the initial torque, and use the sum as the actual loss torque.

4. The engine starting control method for a hybrid vehicle according to claim 2 or 3, characterized in that, The combustion torque is obtained by the following formula: T 燃烧 = p i × s × cosβ × r × sin(α + β), Among them, T 燃烧 is the combustion torque, β = arcsin(r×sinα÷l), which is the crankshaft connecting rod swing angle, l is the crankshaft connecting rod length, r is the crank radius, s is the surface area of the piston head in the cylinder, α is the crank angle, p i is the combustion explosion pressure in the cylinder.

5. The engine starting control method for a hybrid vehicle according to any one of claims 2-4, characterized in that, The rotational torque is obtained by the following formula: T 转矩 = J × a i , Among them, T 转矩 is the rotational torque, J is the moment of inertia of the transmission shaft, and a i =(w i -w i-1 ) / t, which is the angular acceleration of the crankshaft at the i-th moment, w i is the angular velocity of the crankshaft at the i-th moment, and t is the time difference between the i-th moment and the (i - 1)-th moment.

6. The engine starting control method for a hybrid vehicle according to any one of claims 2-5, characterized in that, The controlling the ISG motor of the hybrid vehicle according to the working loss torque includes: Obtain the target torque of the ISG motor according to the working loss torque, the rotational torque and the combustion torque; Perform load control and unloading control on the ISG motor according to the target torque.

7. The engine starting control method for a hybrid vehicle according to claim 6, characterized in that, the method further includes: Judge whether the engine is in a uniform rotation process according to the crankshaft angular velocity; If the engine is in a uniform rotation process, adjust the fuel injection, ignition and intake of the engine to make the ISG motor work smoothly; If the engine is in a non-uniform rotation process, determine the load slope and unloading slope of the ISG motor according to the change of the rotational torque, and perform load control on the ISG motor according to the load slope, and perform unloading control on the ISG motor according to the unloading slope.

8. A computer-readable storage medium, on which a computer program is stored, characterized in that, When the computer program is executed by a processor, it implements the engine starting control method for a hybrid vehicle according to any one of claims 1-7.

9. A controller, characterized in that it includes a memory, a processor, and a computer program stored on the memory, and when the computer program is executed by the processor, it implements the engine starting control method for a hybrid vehicle according to any one of claims 1-7.

10. A hybrid vehicle, characterized in that it includes: an engine, an ISG motor, and a controller according to claim 9.

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