Method, device, vehicle and storage medium for starting an engine

Abstract

This application provides a method, apparatus, vehicle, and storage medium for starting an engine. The target motor drives the engine to rotate via a target belt, thereby starting the engine. Typically, when the target belt is in operation, the acceleration of the target motor and the acceleration of the engine have a fixed numerical relationship (target transmission ratio). Therefore, during actual engine starting, the slippage rate of the target belt can be accurately calculated based on the acceleration of the target motor, the acceleration of the engine, and the target transmission ratio. Thus, even with a high slippage rate, the engine can be started using a starter motor, allowing the vehicle to run. Furthermore, this avoids the problems in related technologies where the engine cannot be started by belt when the slippage is severe; or where the input current of the target motor is too high when the slippage is severe, damaging some electrical components in the vehicle.

Description

Technical Field

[0001] This application relates to the field of vehicles, and more specifically, to methods, apparatus, vehicles, and storage media for starting an engine in the field of vehicles. Background Technology

[0002] To protect the environment in which people live, various vehicle manufacturers have introduced new energy vehicles. For example, plug-in hybrid electric vehicles (PHEVs) are a type of new energy vehicle that falls between pure electric vehicles and gasoline-powered vehicles. These vehicles start the engine by controlling the rotation of a belt-driven starter generator (BSG) motor mounted at the front of the engine, which in turn causes the BSG motor's belt to drive the crankshaft pulley of the engine.

[0003] However, during normal vehicle use, cars may frequently travel on gravel roads. This can cause sand and gravel to become embedded in the belt grooves, loosening the belt and reducing its friction, leading to belt slippage. In cases of severe belt slippage, the car may experience the following problems: when the BSG motor is rotating at a high speed, the engine speed increases very slowly or remains stationary, preventing the engine from starting; the BSG motor speed increases rapidly, causing a rapid increase in its input current, which poses a risk of damaging electrical components in the car. Therefore, how to measure the degree of belt slippage and control the engine starting method accordingly is a pressing issue that needs to be addressed. Summary of the Invention

[0004] This application provides a method, apparatus, vehicle, and storage medium for starting an engine. The method accurately calculates the slippage rate of a target belt. When the slippage rate is high, the engine is started using a starter motor, enabling the vehicle to run. Furthermore, it avoids the problems in related technologies where severe belt slippage prevents engine starting or damages electrical components in the vehicle.

[0005] In a first aspect, a method for starting an engine is provided, the method comprising: in response to a vehicle being powered on and the engine in the vehicle being started, determining a first acceleration of a target motor in the vehicle and a second acceleration of the engine within a preset time period, the target motor driving the engine to rotate via a target belt; determining a slip rate of a target belt based on the first acceleration, the second acceleration, and a target transmission ratio, the target transmission ratio being the transmission ratio between the target motor and the engine when the target belt is driven; and, if the slip rate is greater than a preset slip rate, controlling the target motor to stop driving the engine, and controlling a starter motor in the vehicle to start the engine.

[0006] In the above technical solution, the target motor drives the engine to rotate via a target belt, thereby starting the engine. Typically, when the target belt is in operation, the acceleration of the target motor and the acceleration of the engine have a fixed numerical relationship (target transmission ratio). Therefore, during the actual engine starting process, the slippage rate of the target belt can be accurately calculated based on the acceleration of the target motor, the acceleration of the engine, and the target transmission ratio. Thus, even with a high slippage rate, the engine can be started using the starter motor, allowing the vehicle to run. Furthermore, this solution avoids the problems in related technologies where the engine cannot be started via the target belt when the belt slippage is severe; or where the input current of the target motor is too high when the belt slippage is severe, damaging some electrical components in the vehicle.

[0007] In conjunction with the first aspect, in some possible implementations, the preset time period is the time from the start of the engine to the time corresponding to the first duration of rotation of the target motor. Determining the first acceleration of the target motor and the second acceleration of the engine in the vehicle within the preset time period includes: acquiring the change in rotational speed of the target motor within the preset time period, and acquiring the change in rotational speed of the engine within the preset time period; determining the first acceleration based on the change in rotational speed of the target motor and the preset time period, and determining the second acceleration based on the change in rotational speed of the engine and the preset time period.

[0008] The above technical solution describes the process of acquiring the acceleration (first acceleration) of the target motor during rotation and the acceleration (second acceleration) of the engine during rotation. During engine startup, the target motor rotates, causing the target belt drive to rotate, thereby driving the engine. Therefore, within a preset time period during engine startup, the first acceleration of the target motor can be accurately determined based on the change in its rotational speed; and within a preset time period during engine startup, the second acceleration of the engine can be accurately determined based on the change in its rotational speed.

[0009] In conjunction with the first aspect and the above implementation, in some possible implementations, before determining the slip rate of the target belt based on the first acceleration, the second acceleration, and the target transmission ratio, the method further includes: determining whether the second acceleration is less than a preset acceleration, the preset acceleration being obtained based on the first acceleration and the target transmission ratio; and if the second acceleration is less than the preset acceleration, performing the step of determining the slip rate based on the first acceleration, the second acceleration, and the target transmission ratio.

[0010] In the aforementioned technical solution, under normal circumstances, the preset acceleration (the acceleration that should be achieved) of the engine during rotation can be accurately determined based on the acceleration of the target motor during rotation and the target transmission ratio. When the actual acceleration of the engine (the second acceleration) is less than the preset acceleration, it indicates that the target belt may be slipping. Therefore, after determining that the target belt may be slipping based on the second acceleration and the preset acceleration, the slippage rate is then specifically determined based on the first acceleration, the second acceleration, and the target transmission ratio. Relatively speaking, this application avoids the process of determining the slippage rate multiple times through this solution, reducing the consumption of computational resources.

[0011] In combination with the first aspect and the above-described implementation methods, in some possible implementation methods, the slippage rate of the target belt is determined based on the first acceleration, the second acceleration, and the target transmission ratio, including:

[0012] The slippage rate of the target belt is determined based on the following formula;

[0013] ρ=(a1 / a2-σ) / σ;

[0014] Where ρ is the slip ratio, a1 is the first acceleration, a2 is the second acceleration, and σ is the target transmission ratio.

[0015] In combination with the first aspect and the above implementation methods, in some possible implementation methods, the method further includes: obtaining the rotational speed of the target motor and the operating current of the target motor at the moment corresponding to the first rotational duration; if the rotational speed of the target motor is greater than the preset rotational speed or the operating current is greater than the preset current, controlling the target motor to stop driving the engine, and controlling the starter to start the engine.

[0016] In the above technical solution, under normal conditions, the target motor rotates, causing the target belt to drive the engine. Because the target motor needs to drive both the target belt and the engine, its rotational speed will not drastically increase to a certain value (preset speed), nor will its operating current drastically increase to a certain value (preset current). Therefore, during actual engine starting, if the target motor's rotational speed exceeds the preset speed or its operating current exceeds the preset current, it indicates a problem with the engine starting process, and the target belt may be severely slipping. To avoid potential problems with starting the engine using the target motor, such as failure to start the engine or damage to some electrical components in the vehicle, the engine can be started using a starter motor.

[0017] In combination with the first aspect and the above implementation methods, in some possible implementation methods, the method for determining the preset slip rate includes: obtaining the current-limiting speed of the target motor when it is running at maximum current and the idle speed of the engine; determining the target slip rate based on the current-limiting speed, the idle speed and the target gear ratio; determining the target slip rate as the preset slip rate; or, determining the difference between the target slip rate and a first slip rate as the preset slip rate, wherein the first slip rate is any slip rate less than the target slip rate.

[0018] In the above technical solution, while the target motor rotates at a current-limited speed, causing the target belt to drive the engine to start, the engine can rotate at idle speed. This is equivalent to the target motor starting the engine with maximum current, causing the engine to reach idle speed, at which point the slippage rate of the target belt is at a critical point, i.e., the maximum allowable slippage rate for the vehicle. As long as the vehicle's slippage rate does not exceed this maximum slippage rate, the vehicle can start the engine via the target motor. Furthermore, typically, when the target belt is in operation, the acceleration of the target motor and the acceleration of the engine have a fixed numerical relationship (target transmission ratio). Therefore, this application can accurately determine the target slippage rate using the current-limited speed, the idle speed, and the target transmission ratio. After determining the target slippage rate, it can be directly set as the preset slippage rate; or, to allow for a safety margin, a slippage rate less than the target slippage rate can be set as the preset slippage rate. Finally, this preset slippage rate is used as the basis for determining the actual engine starting method.

[0019] Combining the first aspect and the above implementation methods, in some possible implementation methods, the target slip ratio is determined based on the current-limiting speed, the idle speed, and the target gear ratio, including:

[0020] The target slip ratio is determined based on the following formula;

[0021] ρ * = (n1 / σ-n2) / n2;

[0022] Where, ρ * Let n1 be the target slip ratio, n1 be the current-limiting speed, σ be the target transmission ratio, and n2 be the idle speed.

[0023] In a second aspect, an engine starting device is provided, comprising: a determining module, configured to: in response to a vehicle being powered on and an engine in the vehicle being started, determine a first acceleration of a target motor in the vehicle and a second acceleration of the engine within a preset time period, wherein the target motor drives the engine to rotate via a target belt; determine a slip rate of a target belt based on the first acceleration, the second acceleration, and a target transmission ratio, wherein the target transmission ratio is the transmission ratio between the target motor and the engine when the target belt is driven; and a control module, configured to, if the slip rate is greater than a preset slip rate, control the target motor to stop driving the engine and control a starter motor in the vehicle to start the engine.

[0024] In conjunction with the second aspect, in some possible implementations, the preset time period is the time from the start of the engine to the time corresponding to the first rotation duration of the target motor. The determining module is specifically used to: obtain the change in the rotational speed of the target motor within the preset time period, and obtain the change in the rotational speed of the engine within the preset time period; determine the first acceleration based on the change in the rotational speed of the target motor and the preset time period, and determine the second acceleration based on the change in the rotational speed of the engine and the preset time period.

[0025] In conjunction with the second aspect and the above implementation, in some possible implementations, before determining the slip rate of the target belt based on the first acceleration, the second acceleration, and the target transmission ratio, the determining module is further configured to determine whether the second acceleration is less than a preset acceleration, the preset acceleration being obtained based on the first acceleration and the target transmission ratio; if the second acceleration is less than the preset acceleration, the step of determining the slip rate based on the first acceleration, the second acceleration, and the target transmission ratio is performed.

[0026] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the determining module is specifically used to: determine the slippage rate of the target belt based on the following formula;

[0027] ρ=(a1 / a2-σ) / σ;

[0028] Where ρ is the slip ratio, a1 is the first acceleration, a2 is the second acceleration, and σ is the target transmission ratio.

[0029] In conjunction with the second aspect and the above implementation methods, in some possible implementation methods, the device further includes: an acquisition module, used to acquire the rotational speed of the target motor and the operating current of the target motor when it rotates for a first time duration; the control module is further used to control the target motor to stop driving the engine and control the starter to start the engine when the rotational speed of the target motor is greater than a preset speed or the operating current is greater than a preset current.

[0030] In conjunction with the second aspect and the above implementation methods, in some possible implementation methods, the acquisition module is further configured to acquire the current-limiting speed of the target motor when it is running at maximum current and the idle speed of the engine; the determination module is further configured to: determine a target slip ratio based on the current-limiting speed, the idle speed and the target gear ratio; determine the target slip ratio as the preset slip ratio; or, determine the difference between the target slip ratio and a first slip ratio as the preset slip ratio, wherein the first slip ratio is any slip ratio less than the target slip ratio.

[0031] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the determining module is specifically used to: determine the target slip rate based on the following formula;

[0032] ρ * = (n1 / σ-n2) / n2;

[0033] Where, ρ * Let n1 be the target slip ratio, n1 be the current-limiting speed, σ be the target transmission ratio, and n2 be the idle speed.

[0034] Thirdly, a vehicle is provided, including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein when the processor executes the computer program, the vehicle performs the method described in the first aspect or any possible implementation thereof.

[0035] Fourthly, a computer-readable storage medium is provided that stores instructions which, when executed on a computer or processor, cause the computer or processor to perform the methods described in the first aspect or any possible implementation thereof. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of a BSG motor power system provided in an embodiment of this application;

[0037] Figure 2 This is a schematic flowchart illustrating a method for starting an engine provided in an embodiment of this application;

[0038] Figure 3 This is a flowchart illustrating an engine starting procedure provided in an embodiment of this application;

[0039] Figure 4 This is a schematic diagram of the structure of an engine starting device provided in an embodiment of this application;

[0040] Figure 5 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application. Detailed Implementation

[0041] The technical solutions of this application will now be described clearly and in detail with reference to the accompanying drawings. In the description of the embodiments of this application, "multiple" refers to two or more. The terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Therefore, features defined as "first," "second," "third," "fourth," "fifth," and "sixth" may explicitly or implicitly include one or more of that feature.

[0042] Figure 1 This is a schematic diagram of the structure of a BSG motor power system provided in an embodiment of this application.

[0043] It should be understood that the BSG (Belt-Driven Starter Generator) motor mentioned above is specifically an integrated unit that combines belt drive for starting and generating electricity. On one hand, the BSG motor acts as a starter in the vehicle (i.e., to start the engine). Specifically, the BSG motor increases the engine speed from zero to above idle speed in a short time through belt drive, thus achieving the purpose of starting the engine. On the other hand, the BSG motor acts as a generator in the vehicle (to supply power to the vehicle's battery). Specifically, the rotating engine drives the BSG motor through the belt, thereby converting mechanical energy into electrical energy to power the vehicle's battery (which may be a storage battery).

[0044] Optionally, the vehicle is a hybrid vehicle, which is a plug-in hybrid electric vehicle (PHEV) or a range-extended electric vehicle (REEV).

[0045] This application primarily discusses the process of a BSG motor acting as a starter in a vehicle. For example, such as... Figure 1 As shown, the BSG motor power system 100 includes a battery 101, a BSG motor 102, a belt 103, an engine 104, a clutch 105, a transmission 106, and a starter 107. The battery 101 is connected to the BSG motor 102. The pulley of the BSG motor 102 is connected to the crankshaft pulley at the front end of the engine 104 via the belt 103. The clutch 105 is connected to the engine 104, the transmission 106 is connected to the clutch 105, and the starter 107 is connected to the engine 104.

[0046] It should be understood that, under normal circumstances, the vehicle starts the engine 104 via the BSG motor 102, while starting the engine 104 via the starter motor 107 is an alternative.

[0047] In some embodiments, the vehicle controller controls the battery 101 to supply electrical energy to the BSG motor 102, causing the BSG motor 102 to rotate, which in turn causes the pulley of the BSG motor 102 to rotate. With the pulley rotating, the belt 103 is driven. With the belt 103 driving, the crankshaft pulley at the front end of the engine 104 is driven to rotate, causing the engine 104 to rotate. When the engine speed of the engine 104 equals its idle speed, the engine 104 starts successfully. After the engine 104 starts, when the clutch 105 engages, the clutch 105 transmits the power of the engine 104 to the transmission 106. The transmission 106 matches the power of the engine 104 to the wheels of the vehicle, causing the wheels to rotate and thus driving the vehicle forward.

[0048] In other embodiments, if the vehicle does not use the BSG motor 102 to start the engine 104 during the current engine starting process, the vehicle controller can control the drive gear of the starter 107 to rotate and pop out. When the drive wheel pops out, the controller controls the drive gear to mesh with the flywheel of the engine 104, so that the engine 104 rotates when the drive gear rotates. When the speed of the engine 104 is equal to the idle speed of the engine 104, the engine 104 starts successfully. After the engine 104 starts, when the clutch 105 engages, the clutch 105 transmits the power of the engine 104 to the transmission 106. The transmission 106 matches the power of the engine 104 to the wheels in the vehicle, so that the wheels rotate, thereby driving the vehicle. It should also be understood that if the vehicle needs to switch the engine starting method of the engine 104 to start with the starter 107 during the current engine starting process, the vehicle controller in the vehicle also needs to first control the battery 101 not to supply power to the BSG motor 102, so that the BSG motor 102 does not drive the belt 103. The vehicle controller then starts the engine 104 via the starter motor 107.

[0049] During normal vehicle use, users may frequently drive in environments with a lot of sand and gravel. This can cause sand and gravel to become embedded in the grooves of the belt 103, making the belt 103 loose and reducing its friction. When the pulley of the BSG motor 102 is rotating, insufficient friction on the belt 103 can cause slippage between the pulley or crankshaft pulley and the belt 103, preventing the pulley from effectively driving the crankshaft pulley at the front of the engine 104. In severe cases, this can lead to the inability to start the engine 104, or, if the BSG motor is operating at high speeds, the high current can damage some electrical components in the vehicle. See the explanation below for details.

[0050] The work done by the BSG motor in a vehicle per unit time (i.e., output power P) can be measured by the following formula: P = n * M / 9550 = UIτ, where P is the output power of the BSG motor, n is the speed of the BSG motor, M is the output torque of the BSG motor, 9550 is a fixed coefficient, U is the operating voltage of the BSG motor, I is the operating current of the BSG motor, and Σ is the conversion efficiency, which is a fixed value. From this formula, it can be seen that the speed of the BSG motor is directly proportional to its operating current. During vehicle startup, if the belt driven by the BSG motor slips, the speed of the BSG motor will quickly exceed a certain threshold, causing the operating current of the BSG motor to exceed its limit (e.g., 300A; under normal starting conditions, the operating current of the BSG motor is less than 200A), triggering the current limiting protection. Therefore, the vehicle controller stops sending a stop signal to the BSG motor, resulting in the engine failing to start. Alternatively, if the current limiting protection is not activated in time, it may directly damage the battery.

[0051] In view of the problems existing in the prior art, this application proposes a method for starting an engine, as shown in the following embodiment.

[0052] Figure 2 This is a schematic flowchart of a method for starting an engine provided in an embodiment of this application.

[0053] It should be understood that the method for starting an engine provided in this application embodiment can be applied to, including, Figure 1 The vehicle shown is equipped with the BSG motor power system 100. Specifically, this method of starting the engine can be applied to the vehicle's overall controller.

[0054] For example, such as Figure 2 As shown, the method 200 includes:

[0055] Step 201: In response to the vehicle being powered on and the engine in the vehicle being started, the vehicle controller determines the first acceleration of the target motor and the second acceleration of the engine in the vehicle within a preset time period. The target motor drives the engine to rotate through the target belt.

[0056] It should be understood that "the vehicle is powered on and the engine in the vehicle is started" in step 201 above specifically means that the vehicle receives the instruction from the car key to start the engine, the vehicle's power supply switches from the disconnected state to the connected state, and the brake pedal in the vehicle receives external pressure, thereby putting the engine in the starting condition.

[0057] It should also be understood that the preset time period is a certain period of time during the engine's startup process, which is from the moment the engine starts to the moment corresponding to the first duration of the target motor's rotation.

[0058] It should also be understood that the "engine" in step 201 can be considered as Figure 1 The engine 104 in the middle, and the "target motor" in step 201 can be regarded as Figure 1 The BSG motor 103 in the middle, and the "target belt" in step 201 can be regarded as Figure 1 The belt 103 in the middle.

[0059] In one possible implementation, the preset time period is from the moment the engine starts to the moment corresponding to the first duration of rotation of the target motor. The vehicle controller determines the first acceleration of the target motor and the second acceleration of the engine in the vehicle within the preset time period, including: the vehicle controller acquiring the change in rotational speed of the target motor and the change in rotational speed of the engine within the preset time period; the vehicle controller determining the first acceleration based on the change in rotational speed of the target motor and the preset time period, and determining the second acceleration based on the change in rotational speed of the engine and the preset time period.

[0060] The above technical solution describes the process of acquiring the acceleration (first acceleration) of the target motor during rotation and the acceleration (second acceleration) of the engine during rotation. During engine startup, the target motor rotates, causing the target belt drive to rotate, thereby driving the engine. Therefore, within a preset time period during engine startup, the first acceleration of the target motor can be accurately determined based on the change in its rotational speed; and within a preset time period during engine startup, the second acceleration of the engine can be accurately determined based on the change in its rotational speed.

[0061] In some embodiments, the vehicle controller acquires the change in rotational speed of the target motor and the change in rotational speed of the engine within the preset time period, including: the vehicle controller acquires a first rotational speed of the target motor and a second rotational speed of the engine at the moment the engine starts; the vehicle controller acquires a third rotational speed of the target motor and a fourth rotational speed of the engine at a moment corresponding to a first rotational duration of the target motor; the vehicle controller determines the speed difference between the third rotational speed and the first rotational speed as the change in rotational speed of the target motor; and the vehicle controller determines the speed difference between the fourth rotational speed and the second rotational speed as the change in rotational speed of the engine.

[0062] It should be understood that since the preset time period is from the moment the engine starts to the moment corresponding to the first rotation duration of the target motor, the first rotational speed of the target motor is 0, and the second rotational speed of the engine is 0. That is to say, the change in rotational speed of the target motor is the third rotational speed of the target motor, and the change in rotational speed of the engine is the fourth rotational speed of the engine.

[0063] In some embodiments, the vehicle controller determines the first acceleration based on the change in the rotational speed of the target motor and the preset time period, and determines the second acceleration based on the change in the rotational speed of the engine and the preset time period, including: the vehicle controller determining the ratio between the change in the rotational speed of the target motor and the preset time period as the first acceleration; and the vehicle controller determining the ratio between the change in the rotational speed of the engine and the preset time period as the second acceleration.

[0064] For example, taking a target motor speed change of 1200 rpm (the third speed is 1200 rpm) and an engine speed change of 430 rpm (the fourth speed is 430 rpm), with a preset time period of 200 ms, the process of the vehicle controller determining the first and second accelerations is described. Based on the first formula: 1200 rpm / (200 ms / 1000 / 60), the vehicle controller obtains the first acceleration as 360000 rpm / min. 2 The vehicle controller, based on the second formula: 430rpm / (200ms / 1000 / 60), obtains the second acceleration as 129000rpm / min. 2 .

[0065] It should be understood that the vehicle controller divides the preset time period of 200ms by 1000 and then by 60 in order to convert the preset time period from the millisecond level to the minute level.

[0066] Step 202: The vehicle controller determines the slip rate of the target belt based on the first acceleration, the second acceleration, and the target transmission ratio. The target transmission ratio is the transmission ratio between the target motor and the engine when the target belt is driven.

[0067] It should be understood that the "slippage rate" in step 202 above can be simply understood as the reciprocal of the frictional force between the target motor pulley or the engine crankshaft pulley and the target belt. In other words, the lower the frictional force between the pulley and the crankshaft pulley, the higher the slippage rate of the target belt. Conversely, the higher the frictional force between the pulley and the crankshaft pulley, the lower the slippage rate of the target belt. When the slippage rate of the target belt is high, the rotation of the pulley may not effectively drive the crankshaft pulley at the front of the engine, potentially causing the engine to fail to start.

[0068] In one possible implementation, before step 202, the method 200 further includes: the vehicle controller determining whether the second acceleration is less than a preset acceleration, the preset acceleration being obtained based on the first acceleration and the target gear ratio; if the second acceleration is less than the preset acceleration, the vehicle controller performs the step of determining the slip rate based on the first acceleration, the second acceleration, and the target gear ratio.

[0069] In the aforementioned technical solution, under normal circumstances, the preset acceleration (the acceleration that should be achieved) of the engine during rotation can be accurately determined based on the acceleration of the target motor during rotation and the target transmission ratio. When the actual acceleration of the engine (the second acceleration) is less than the preset acceleration, it indicates that the target belt may be slipping. Therefore, after determining that the target belt may be slipping based on the second acceleration and the preset acceleration, the slippage rate is then specifically determined based on the first acceleration, the second acceleration, and the target transmission ratio. Relatively speaking, this application avoids the process of determining the slippage rate multiple times through this solution, reducing the consumption of computational resources.

[0070] In some embodiments, the method for determining the preset acceleration includes: the vehicle controller determining a target acceleration based on the following formula (1); the vehicle controller determining the target acceleration as the preset acceleration; or, the vehicle controller determining the difference between the target acceleration and a third acceleration as the preset acceleration;

[0071] σ= a1 / a0 (1)

[0072] Where σ is the target transmission ratio, a1 is the first acceleration, and a0 is the target acceleration.

[0073] In the above technical solution, the preset acceleration is determined in two ways, which can meet different requirements for preset acceleration. In particular, the vehicle controller determines the difference between the target acceleration and the third acceleration as the preset acceleration in order to reserve a certain safety margin.

[0074] In one possible implementation, step 202 includes: the vehicle controller determining the slip rate of the target belt based on the following formula (2);

[0075] ρ=(a1 / a2-σ) / σ (2)

[0076] Where ρ is the slip ratio, a1 is the first acceleration, a2 is the second acceleration, and σ is the target transmission ratio.

[0077] Step 203: If the slip rate is greater than the preset slip rate, the vehicle controller controls the target motor to stop driving the engine and controls the starter motor in the vehicle to start the engine.

[0078] In some embodiments, the "preset slip rate" in step 203 above can be the maximum allowable slip rate of the target belt during the process of starting the engine using the target motor. Alternatively, the preset slip rate can be a slip rate that is slightly lower than the maximum slip rate, in order to reserve a safety margin to prevent certain unforeseen circumstances from occurring.

[0079] It should be understood that if the actual slip rate when starting the engine is greater than the preset slip rate, continuing to use the target motor to start the engine may lead to some accidents: 1) failure to start the engine successfully; 2) during the engine starting process, the speed of the target motor exceeds the current-limiting speed of the target motor at the maximum operating current, damaging some electrical components in the vehicle, such as the battery 101.

[0080] In one possible implementation, the method for determining the preset slip ratio in step 203 includes: the vehicle controller acquiring the current-limited speed of the target motor when it rotates at maximum current and the idle speed of the engine; the vehicle controller determining the target slip ratio based on the current-limited speed, the idle speed, and the target gear ratio; and determining the target slip ratio as the preset slip ratio; or, the vehicle controller determining the difference between the target slip ratio and a first slip ratio as the preset slip ratio, wherein the first slip ratio is any slip ratio less than the target slip ratio.

[0081] It should be understood that the "current-limiting speed of the target motor" in the above scheme can be simply understood as the maximum speed that the target motor can achieve. The "idle speed of the engine" in the above scheme can be understood as the engine speed when the engine is in idle condition (the state when the engine is running without load), that is, the speed when the engine is running at idle.

[0082] In the above technical solution, while the target motor rotates at a current-limited speed, causing the target belt to drive the engine to start, the engine can rotate at idle speed. This is equivalent to the target motor starting the engine with maximum current, causing the engine to reach idle speed, at which point the slippage rate of the target belt is at a critical point, i.e., the maximum allowable slippage rate for the vehicle. As long as the vehicle's slippage rate does not exceed this maximum slippage rate, the vehicle can start the engine via the target motor. Furthermore, typically, when the target belt is in operation, the acceleration of the target motor and the acceleration of the engine have a fixed numerical relationship (target transmission ratio). Therefore, this application can accurately determine the target slippage rate using the current-limited speed, the idle speed, and the target transmission ratio. After determining the target slippage rate, it can be directly set as the preset slippage rate; or, to allow for a safety margin, a slippage rate less than the target slippage rate can be set as the preset slippage rate. Finally, this preset slippage rate is used as the basis for determining the actual engine starting method.

[0083] For example, taking a target slip rate of 0.5 and a first slip rate of 0.05 as an example, the process of determining the preset slip rate is described. The vehicle controller determines 0.5 as the preset slip rate; or, the vehicle controller determines the difference between the target slip rate and the first slip rate (0.5-0.05=0.45) as the preset slip rate.

[0084] Optionally, the vehicle controller determines the target slip ratio based on the current-limiting speed, the idle speed and the target gear ratio, including: the vehicle controller determines the target slip ratio based on the following formula (3);

[0085] ρ * =(n1 / σ-n2) / n2 (3)

[0086] Where, ρ * Here, n1 is the target slip ratio, σ is the target gear ratio, and n2 is the idle speed. It should be understood that the "target slip ratio" in the above scheme is the maximum allowable slip ratio of the target belt under theoretical conditions. It should also be understood that this target slip ratio is the maximum slip ratio in the aforementioned scheme.

[0087] For example, taking the target motor's current-limiting speed as 3400 rpm, the engine's idle speed as 730 rpm, and the target gear ratio as 2.73, the process of determining the target slip ratio is described. The vehicle controller substitutes the above parameters into formula (3) to obtain: ρ * = (3400 / 2.73-730) / 730 = 0.706. The vehicle controller determines this 0.706 as the target slip rate.

[0088] In some embodiments, the vehicle controller controls the starter motor in the vehicle to start the engine, including: the vehicle controller controls the drive gear of the starter motor to rotate and eject; when the drive wheel is ejected, the vehicle controller controls the drive gear to mesh with the flywheel of the engine so as to drive the engine to rotate when the drive gear rotates.

[0089] It should be understood that the "starter motor" in the above scheme can be regarded as Figure 1 The starter motor 107 is located in the middle.

[0090] In the above technical solution, starting the engine through a primitive mechanical method can avoid the problem of being unable to start the engine due to severe slippage of the target belt.

[0091] In some embodiments, after step 203, the method 200 further includes: if the slip rate is less than or equal to the preset slip rate, the vehicle controller continues to control the target motor to drive the engine to rotate via the target belt drive.

[0092] In the above technical solution, when the slippage rate is small, the engine continues to be started through the target motor. This allows the engine to directly bypass the low-speed vibration zone during the start-up process, achieving a fast and smooth start.

[0093] In one possible implementation, after step 203, the method 200 further includes: the vehicle controller acquiring the rotational speed of the target motor and the operating current of the target motor at the moment corresponding to the first rotational duration; if the rotational speed of the target motor is greater than a preset speed or the operating current is greater than a preset current, the vehicle controller controls the target motor to stop driving the engine and controls the starter to start the engine.

[0094] It should be understood that "the rotational speed of the target motor at the moment corresponding to the first rotational duration" in the above scheme refers to the third rotational speed of the target motor in the aforementioned scheme.

[0095] In the above technical solution, under normal conditions, the target motor rotates, causing the target belt to drive the engine. Because the target motor needs to drive both the target belt and the engine, its rotational speed will not drastically increase to a certain value (preset speed), nor will its operating current drastically increase to a certain value (preset current). Therefore, during actual engine starting, if the target motor's rotational speed exceeds the preset speed or its operating current exceeds the preset current, it indicates a problem with the engine starting process, and the target belt may be severely slipping. To avoid potential problems with starting the engine using the target motor, such as failure to start the engine or damage to some electrical components in the vehicle, the engine can be started using a starter motor.

[0096] In this application, other methods can also be used to determine whether to start the engine using a starter motor. The specific implementation process is as follows.

[0097] In some embodiments, in response to the vehicle being powered on and the engine in the vehicle being started, the vehicle controller acquires the rotational speed of the target motor and the rotational speed of the engine at a first moment; the vehicle controller determines whether the rotational speed of the engine is less than a fifth rotational speed, which is obtained based on the rotational speed of the target motor and the target gear ratio; if the rotational speed of the engine is less than the fifth rotational speed, the vehicle controller controls the target motor to stop driving the engine and controls the starter motor to start the engine.

[0098] It should be understood that in the above scheme, "first moment" refers to a certain moment during the engine's startup process, and "target transmission ratio" has the same meaning as the target transmission ratio in step 202. "Fifth speed" is the minimum engine speed allowed by the vehicle when the target belt slips; this fifth speed is related to the target motor speed and the target transmission ratio at the current moment. Taking the above scheme as an example, this fifth speed is related to the target transmission ratio and the target motor speed at the first moment. In another example, the vehicle controller obtains the target motor speed and engine speed at the second moment; the vehicle controller determines whether the engine speed is less than the fifth speed, then the fifth speed is related to the target transmission ratio and the target motor speed at the second moment.

[0099] In some embodiments, the method for determining the fifth rotational speed includes: the vehicle controller determining the sixth rotational speed based on the following formula (4); the vehicle controller determining the difference between the sixth rotational speed and the target rotational speed as the fifth rotational speed;

[0100] σ= a * / a6 (4)

[0101] Where σ is the target transmission ratio, a * a6 represents the target motor speed, and a6 represents the fifth speed.

[0102] In other embodiments, the vehicle controller responds to the vehicle being powered on and the engine in the vehicle being started, and obtains the engine speed at a third moment; if the engine speed is 0 at the third moment, the vehicle controller controls the target motor to stop driving the engine and controls the starter motor to start the engine.

[0103] It should be understood that the above scheme can be interpreted as the target motors rotating at a relatively high speed, but the engine speed is still 0, indicating that the target belt has a high slippage rate and the target belt cannot drive the engine crankshaft pulley to rotate, thus making it impossible to start the engine.

[0104] Figure 3 This is a flowchart illustrating an engine starting process provided in an embodiment of this application.

[0105] For example, in step 301, in response to the vehicle being powered on and the engine starting, the vehicle controller determines a first acceleration of the target motor and a second acceleration of the engine within a preset time period. The target motor drives the engine to rotate via a target belt. In step 302, based on the first acceleration, the second acceleration, and a target transmission ratio, the vehicle controller determines the slippage rate of the target belt. The target transmission ratio is the transmission ratio between the target motor and the engine when the target belt is in operation. In step 303, if the slippage rate is greater than a preset slippage rate, the vehicle controller controls the target motor to stop driving the engine and controls the starter motor in the vehicle to start the engine. In step 304, if the slippage rate is less than or equal to the preset slippage rate, the vehicle controller continues to control the target motor to drive the engine to rotate via the target belt.

[0106] Figure 4 This is a schematic diagram of a device for starting an engine provided in an embodiment of this application.

[0107] For example, such as Figure 4 As shown, the device 400 includes:

[0108] The determining module 401 is configured to: in response to the vehicle being powered on and the engine in the vehicle being started, determine a first acceleration of a target motor and a second acceleration of the engine in the vehicle within a preset time period, wherein the target motor drives the engine to rotate via a target belt; and determine the slip rate of the target belt based on the first acceleration, the second acceleration, and a target transmission ratio, wherein the target transmission ratio is the transmission ratio between the target motor and the engine when the target belt is driven.

[0109] The control module 402 is used to control the target motor to stop driving the engine and control the starter motor in the vehicle to start the engine when the slip rate is greater than the preset slip rate.

[0110] Optionally, the preset time period is from the moment the engine starts to the moment corresponding to the first rotation duration of the target motor. The determining module 401 is specifically used to: obtain the change in the rotational speed of the target motor within the preset time period, and obtain the change in the rotational speed of the engine within the preset time period; determine the first acceleration based on the change in the rotational speed of the target motor and the preset time period, and determine the second acceleration based on the change in the rotational speed of the engine and the preset time period.

[0111] Optionally, before determining the slip rate of the target belt based on the first acceleration, the second acceleration, and the target transmission ratio, the determining module 401 is further configured to determine whether the second acceleration is less than a preset acceleration, the preset acceleration being obtained based on the first acceleration and the target transmission ratio; if the second acceleration is less than the preset acceleration, the step of determining the slip rate based on the first acceleration, the second acceleration, and the target transmission ratio is performed.

[0112] Optionally, the determining module 401 is further configured to: determine the slippage rate of the target belt based on the following formula;

[0113] ρ=(a1 / a2-σ) / σ;

[0114] Where ρ is the slip ratio, a1 is the first acceleration, a2 is the second acceleration, and σ is the target transmission ratio.

[0115] Optionally, the device 400 further includes: an acquisition module, used to acquire the rotational speed of the target motor and the operating current of the target motor at the moment corresponding to the first rotational duration; the control module 402 is further used to control the target motor to stop driving the engine and control the starter to start the engine when the rotational speed of the target motor is greater than a preset speed or the operating current is greater than a preset current.

[0116] Optionally, the acquisition module is further configured to acquire the current-limited speed of the target motor and the idle speed of the engine when the target motor is running at maximum current; the determination module 401 is further configured to: determine a target slip ratio based on the current-limited speed, the idle speed and the target gear ratio; determine the target slip ratio as the preset slip ratio; or, determine the difference between the target slip ratio and a first slip ratio as the preset slip ratio, wherein the first slip ratio is any slip ratio less than the target slip ratio.

[0117] Optionally, the determining module 401 is further configured to: determine the target slip rate based on the following formula;

[0118] ρ * = (n1 / σ-n2) / n2;

[0119] Where, ρ * Let n1 be the target slip ratio, n1 be the current-limiting speed, σ be the target transmission ratio, and n2 be the idle speed.

[0120] Figure 5 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application.

[0121] For example, such as Figure 5As shown, the vehicle 500 includes: a memory 501, a processor 502, and a computer program 503 stored in the memory 501 and running on the processor 502, wherein when the processor 502 executes the computer program 503, the vehicle can perform any of the aforementioned methods for starting the engine.

[0122] This embodiment can divide the vehicle into functional modules according to the above method example. For example, each function can be assigned to a separate module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0123] When each functional module is divided according to its corresponding function, the vehicle may include: a determination module, a control module, and an acquisition module, etc. It should be noted that all relevant content of each step involved in the above method embodiments can be referenced from the functional descriptions of the corresponding functional modules, and will not be repeated here.

[0124] The vehicle provided in this embodiment is used to execute the above-described method for starting an engine, and therefore can achieve the same effect as the above-described implementation method.

[0125] When using integrated units, the vehicle may include a processing module and a storage module. The processing module is used to control and manage the vehicle's actions. The storage module is used for the vehicle to execute program code and store data.

[0126] The processing module may be a processor or a controller, which can implement or execute various exemplary logic blocks, modules, and circuits as disclosed in this application. The processor may also be a combination of computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and microprocessors, etc., and the storage module may be a memory.

[0127] This embodiment provides a computer-readable storage medium storing instructions that, when executed on a computer or processor, cause the computer or processor to perform any of the aforementioned methods for starting an engine.

[0128] This embodiment also provides a computer program product containing instructions that, when run on a computer or processor, causes the computer or processor to perform the aforementioned steps to implement any of the methods for starting an engine described above.

[0129] In this embodiment, the vehicle, computer-readable storage medium, computer program product containing instructions, or chip are all used to execute the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can be referred to the beneficial effects in the corresponding methods provided above, and will not be repeated here.

[0130] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0131] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0132] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for starting an engine, characterized in that, The method includes: In response to the vehicle being powered on and the engine in the vehicle being started, a first acceleration of a target motor in the vehicle and a second acceleration of the engine in the vehicle are determined within a preset time period, wherein the target motor drives the engine to rotate via a target belt; Based on the first acceleration, the second acceleration, and the target transmission ratio, the slippage rate of the target belt is determined, wherein the target transmission ratio is the transmission ratio between the target motor and the engine when the target belt is driven. If the slip rate is greater than the preset slip rate, the target motor is controlled to stop driving the engine, and the starter motor in the vehicle is controlled to start the engine.

2. The method according to claim 1, characterized in that, The preset time period is from the moment the engine starts to the moment corresponding to the first duration of rotation of the target motor. Determining the first acceleration of the target motor and the second acceleration of the engine within the preset time period includes: The change in the rotational speed of the target motor and the change in the rotational speed of the engine are obtained within the preset time period. The first acceleration is determined based on the change in the target motor's rotational speed and the preset time period, and the second acceleration is determined based on the change in the engine's rotational speed and the preset time period.

3. The method according to claim 1, characterized in that, Before determining the slippage rate of the target belt based on the first acceleration, the second acceleration, and the target transmission ratio, the method further includes: Determine whether the second acceleration is less than a preset acceleration, the preset acceleration being obtained based on the first acceleration and the target transmission ratio; If the second acceleration is less than the preset acceleration, the step of determining the slip rate based on the first acceleration, the second acceleration, and the target transmission ratio is performed.

4. The method according to claim 1, characterized in that, Determining the slippage rate of the target belt based on the first acceleration, the second acceleration, and the target transmission ratio includes: The slippage rate of the target belt is determined based on the following formula; ρ=(a1 / a2-σ) / σ; Wherein, ρ is the slip ratio, a1 is the first acceleration, a2 is the second acceleration, and σ is the target transmission ratio.

5. The method according to any one of claims 1-4, characterized in that, The method further includes: The rotational speed of the target motor and the operating current of the target motor during rotation are obtained at the time corresponding to the first rotation duration. If the target motor's rotational speed is greater than a preset speed or the operating current is greater than a preset current, the target motor is controlled to stop driving the engine, and the starter is controlled to start the engine.

6. The method according to claim 1, characterized in that, The method for determining the preset slip rate includes: Obtain the current-limited speed of the target motor when it is running at maximum current and the idle speed of the engine; The target slip rate is determined based on the current-limiting speed, the idle speed, and the target gear ratio; The target slip rate is determined as the preset slip rate; or, The difference between the target slip rate and the first slip rate is determined as the preset slip rate, wherein the first slip rate is any slip rate less than the target slip rate.

7. The method according to claim 6, characterized in that, Determining the target slip ratio based on the current-limiting speed, the idle speed, and the target gear ratio includes: The target slip ratio is determined based on the following formula; r * =(n1 / σ-n2) / n2; Where, ρ * The target slip ratio is n1, the current-limiting speed is n1, the target transmission ratio is σ, and the idle speed is n2.

8. A device for starting an engine, characterized in that, The device includes: The determination module is used for: In response to the vehicle being powered on and the engine in the vehicle being started, a first acceleration of a target motor in the vehicle and a second acceleration of the engine in the vehicle are determined within a preset time period, wherein the target motor drives the engine to rotate via a target belt; Based on the first acceleration, the second acceleration, and the target transmission ratio, the slippage rate of the target belt is determined, wherein the target transmission ratio is the transmission ratio between the target motor and the engine when the target belt is driven. The control module is used to control the target motor to stop driving the engine and control the starter motor in the vehicle to start the engine when the slip rate is greater than a preset slip rate.

9. A vehicle, characterized in that, The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it causes the vehicle to perform the method of starting the engine as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a computer or processor, cause the computer or processor to perform the method of starting an engine as described in any one of claims 1 to 7.

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