Engine shutdown control method and device of range extender, range extender and automobile

Abstract

The embodiment of the invention provides an engine shutdown control method and device of a range extender, the range extender and an automobile, and relates to the technical field of vehicles. The method comprises the steps that when the rotating speed of an engine is reduced to the preset rotating speed, the first current angle position of a crankshaft is obtained, and the crankshaft is started on the basis of the first current angle position; the target optimal stop position is selected from a plurality of preset optimal stop positions, it is ensured that the stop target of the engine is clear, then the target angle is determined according to the first current angle position and the clear target optimal stop position, the target stop period is determined according to the target angle, and the engine is controlled to stop according to the target stop period. By means of the method, the accuracy of the angle position of the crankshaft when the engine stops is improved, the piston connected with the crankshaft can be close to the optimal stop position as much as possible to stop, the lower the resistance of the piston stop position close to the optimal stop position is, the higher the success rate of next starting of the automobile can be improved, and the NVH performance of the automobile is improved.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to an engine shutdown control method and device for a range extender, a range extender and a vehicle. Background Art

[0002] As a key component of new energy vehicles, the range extender has an important impact on the performance of the vehicle through its engine shutdown control method. At present, the range extender usually controls the engine through a certain reverse torque during the engine shutdown process to reduce the engine speed to complete the shutdown. However, this method is difficult to ensure the accuracy of the crankshaft angle position when the engine is shut down, and the piston connected to the crankshaft cannot stop at the ideal position. When the piston stops at a non-ideal position, the resistance is large, which makes the success rate of the car low when it is started next time, which in turn leads to poor NVH (Noise, Vibration, and Harshness) performance of the car. Summary of the invention

[0003] An object of the present invention is to provide an engine shutdown control method, device, range extender and computer-readable storage medium to solve the problem of poor NVH performance.

[0004] In a first aspect, the present invention provides a method for controlling engine shutdown of a range extender, the method comprising:

[0005] When the engine speed is decelerated to a preset speed, a first current angle position of the crankshaft is obtained; wherein the preset speed is less than the idle speed of the engine;

[0006] Based on the first current angular position, selecting a target optimal stopping position from a plurality of preset optimal stopping positions;

[0007] Determining a target angle based on the first current angle position and the target optimal parking position;

[0008] Based on the target angle and a plurality of preset stop cycle rotation angles, a target stop cycle required for the engine to stop from the preset speed is determined; wherein the stop cycle rotation angle is the angle of rotation of the crankshaft during the process of the engine stopping from the preset speed in the preset stop cycle;

[0009] The engine is controlled to be stopped according to the target stop period.

[0010] In an optional embodiment, determining the target stop cycle required for the engine to stop from the preset speed based on the target angle and a plurality of preset stop cycle rotation angles includes:

[0011] Selecting a stop cycle rotation angle having the smallest difference with the target angle from the plurality of stop cycle rotation angles, and determining the stop cycle rotation angle as the target cycle rotation angle;

[0012] The downtime period corresponding to the target period rotation angle is determined as the target downtime period.

[0013] In an optional embodiment, the engine speed is reduced to a preset speed, comprising:

[0014] The engine speed is controlled to be decelerated from an idle speed to a preset speed.

[0015] In an optional embodiment, if the angle between two adjacent optimal stopping positions among the plurality of optimal stopping positions is greater than the angle threshold, before controlling the engine speed to decelerate from the idle speed to the preset speed, the method further includes:

[0016] At idle speed, obtaining a second current angle position of the crankshaft in real time;

[0017] Comparing the second current angle position with a preset stop start angle range to obtain a comparison result;

[0018] According to the comparison result, it is confirmed that the second current angle position is within a preset angle interval.

[0019] In a second aspect, the present invention provides an engine shutdown control device, comprising:

[0020] A current angle position acquisition module, used to acquire a first current angle position of the crankshaft when the engine speed is decelerated to a preset speed; wherein the preset speed is less than the idle speed of the engine;

[0021] a target angle determination module, configured to select a target optimal stopping position from a plurality of preset optimal stopping positions based on the first current angle position; and determine a target angle based on the first current angle position and the target optimal stopping position;

[0022] A target stop cycle acquisition module is used to determine the target stop cycle required for the engine to stop from the preset speed based on the target angle and a plurality of preset stop cycle rotation angles; wherein the stop cycle rotation angle is the angle of rotation of the crankshaft during the process of the engine stopping from the preset speed with the preset stop cycle;

[0023] A shutdown control module is used to control the engine to shut down according to the target shutdown period.

[0024] In an optional embodiment, determining the target stop cycle required for the engine to stop from the preset speed based on the target angle and a plurality of preset stop cycle rotation angles includes:

[0025] Selecting a stop cycle rotation angle having the smallest difference with the target angle from the plurality of stop cycle rotation angles, and determining the stop cycle rotation angle as the target cycle rotation angle;

[0026] The downtime period corresponding to the target period rotation angle is determined as the target downtime period. In an optional embodiment, the engine speed is decelerated to a preset speed, including:

[0027] The engine speed is controlled to be decelerated from an idle speed to a preset speed.

[0028] In an optional embodiment, the device further includes an initial stop position determination module;

[0029] The initial stop position determination module is used to:

[0030] If the angle between two adjacent optimal stopping positions among the multiple optimal stopping positions is greater than the angle threshold, at the idle speed, the second current angle position of the crankshaft is obtained in real time; the second current angle position is compared with the preset stopping starting angle range to obtain a comparison result; and based on the comparison result, it is confirmed that the second current angle position is within the preset angle range.

[0031] In a third aspect, the present invention provides a range extender, comprising a processor and a memory, wherein the memory stores a computer program executable by the processor, and the computer program executable by the processor is used to implement the engine shutdown control method described in any of the aforementioned embodiments.

[0032] In a fourth aspect, the present invention provides an automobile, comprising the above-mentioned range extender.

[0033] The engine shutdown control method and device of the range extender provided by the embodiment of the present invention, the range extender and the automobile, the method comprising: when the engine speed is decelerated to a preset speed, obtaining a first current angle position of the crankshaft, selecting a target optimal stop position from a plurality of preset optimal stop positions based on the first current angle position, ensuring that the engine shutdown target is clear, and then determining a target angle according to the first current angle position and the clear target optimal stop position, determining a target stop cycle according to the target angle, and controlling the engine shutdown according to the target stop cycle. Implementation of the method improves the accuracy of the angular position of the crankshaft when the engine is shut down, so that the piston connected to the crankshaft can also be shut down as close to the optimal stop position as possible, the closer the piston stop position is to the optimal stop position, the smaller the resistance is, the higher the success rate of the next start of the automobile can be improved, and the NVH performance of the automobile can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 A schematic diagram showing an application environment of the engine shutdown control method provided by an embodiment of the present invention is shown;

[0036] Figure 2 A schematic flow chart of an engine shutdown control method provided by an embodiment of the present invention is shown;

[0037] Figure 3 Another schematic flow chart of an engine shutdown control method provided by an embodiment of the present invention is shown;

[0038] Figure 4 Another schematic flow chart of an engine shutdown control method provided by an embodiment of the present invention is shown;

[0039] Figure 5 Another schematic flow chart of an engine shutdown control method provided by an embodiment of the present invention is shown;

[0040] Figure 6 A module block diagram of an engine shutdown control device provided by an embodiment of the present invention is shown;

[0041] Figure 7 A block diagram of a range extender provided in an embodiment of the present invention is shown.

[0042] Icons: 100 - range extender controller; 200 - generator; 300 - engine; 310 - crankshaft; 400 - engine shutdown control device; 410 - current angle position acquisition module; 420 - target angle determination module; 430 - target shutdown cycle acquisition module; 440 - shutdown control module; 500 - range extender; 510 - memory; 520 - processor; 530 - communication module. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0046] See also Figure 1 , Figure 1 The present invention provides an engine shutdown control method according to an embodiment of the present invention. The engine shutdown control method can be applied to a range extender of an automobile. The range extender includes a range extender controller 100 , a generator 200 and an engine 300 .

[0047] The range extender controller 100 is electrically connected to the generator 200 and the engine 300 respectively. The range extender controller 100 can monitor and adjust the working status of the generator 200 and the engine 300 in real time.

[0048] The engine 300 drives the generator 200 to rotate via the crankshaft 310 so that the generator 200 generates electricity.

[0049] The crankshaft 310 is a key component of the engine 300. When the crankshaft 310 rotates, it drives the rotor of the generator 200 to rotate, so that the generator 200 can generate electricity. The angular position of the crankshaft refers to the rotation angle of the crankshaft relative to a certain reference point. In the engine, the top dead center of a cylinder is usually used as the reference point. At this time, the angular position of the crankshaft is 0 degrees. As the crankshaft rotates, the angle gradually increases. For example, assuming that the current position of the crankshaft 310 is 40 degrees from the top dead center of a cylinder, the current angular position of the crankshaft 310 is 40 degrees.

[0050] See also Figure 2 , Figure 2A schematic diagram of a flow chart of an engine shutdown control method for a range extender provided in an embodiment of the present invention is shown. The engine shutdown control method can be applied to a range extender controller. The specific flow of this embodiment is described below using a range extender controller as an example. Figure 2 The process shown in FIG. 1 is described in detail, and the engine shutdown control method may specifically include the following steps:

[0051] Step 110: When the engine speed is decelerated to a preset speed, a first current angle position of the crankshaft is obtained.

[0052] The preset speed is less than the idle speed of the engine.

[0053] In some embodiments, a preset speed is pre-configured and stored in the range extender controller 100, and the range extender controller 100 controls the engine 300 to decelerate to the preset speed. The operation cycle of the range extender controller 100 is at the microsecond level. In this embodiment, the operation time of the range extender controller 100 to process data can be ignored.

[0054] Through a large number of tests, it is found that the controllability of the engine is higher at the preset speed. If the engine speed is too high, it is not conducive to the angle adjustment of the crankshaft, and there will be more interference; if the engine speed is too low, the engine will be shut down before the angle position of the crankshaft can be adjusted. For example, in this embodiment, the preset speed can be set to 200prm (revolutions per minute). It can be understood that this embodiment does not limit the specific value of the preset speed, and setting it to 200prm is only for the convenience of illustrative description of the method of this application.

[0055] In some embodiments, the engine is provided with a crankshaft position sensor, which can monitor the angular position of the crankshaft in real time. The range extender controller 100 can obtain the first current angular position of the crankshaft at the moment when the speed of the engine 300 is decelerated to a preset speed through the crankshaft position sensor in real time. For example, the speed of the engine 300 is decelerated to 200prm at the i-th moment, and the range extender controller 100 obtains the angular position α of the crankshaft at the i-th moment through the crankshaft position sensor, and the angular position α is the first current angular position.

[0056] Step 120: Based on the first current angular position, a target optimal stopping position is selected from a plurality of preset optimal stopping positions.

[0057] In some implementations, based on the current rotation direction of the crankshaft, an optimal stop position closest to the first current angular position is selected from a plurality of preset optimal stop positions and determined as the target optimal stop position.

[0058] For example, the range extender controller 100 stores multiple optimal stop positions of the crankshaft, namely, optimal stop position A (30 degrees), optimal stop position B (120 degrees), and optimal stop position C (220 degrees). Assuming that the first current angular position is 45 degrees and the current rotation direction of the crankshaft is clockwise, the distance between the first current angular position and the optimal stop position A (30 degrees) is 345 degrees (360-(45-30)=345 degrees), the distance between the first current angular position and the optimal stop position B (120 degrees) is 45 degrees (120-45=75 degrees), and the distance between the first current angular position and the optimal stop position C (220 degrees) is 175 degrees (220-45=175 degrees). The first current angular position is closest to the optimal stop position B (120 degrees), and the optimal stop position B (120 degrees) is determined as the target optimal stop position.

[0059] It should be noted that, from the preset multiple optimal stop positions, the optimal stop position closest to the first current angle position is selected according to the current rotation direction of the crankshaft, and determined as the target optimal stop position. That is, the current rotation direction of the crankshaft needs to be referred to when determining the target optimal stop position. For example, assuming that the current rotation direction of the crankshaft is clockwise and the first current angle position is 45 degrees, if the crankshaft is to reach the optimal stop position B (120 degrees), the crankshaft needs to rotate 75 degrees clockwise (120-45=75 degrees) to reach the optimal stop position B (120 degrees). If the crankshaft is to reach the optimal stop position A (30 degrees), the crankshaft needs to rotate 345 degrees clockwise (360-(45-30)=34 5 degrees), therefore, when the crankshaft rotates clockwise, the optimal stopping position B (120 degrees) is closest to the first current angle position; assuming that the current rotation direction of the crankshaft is counterclockwise, the first current angle position is 45 degrees. If the crankshaft wants to reach the optimal stopping position B (120 degrees), the crankshaft needs to rotate 285 degrees counterclockwise (360-120+45=285 degrees) to reach the optimal stopping position B (120 degrees). If the crankshaft wants to reach the optimal stopping position A (30 degrees), the crankshaft needs to rotate 15 degrees counterclockwise (45-30=15 degrees) to reach the optimal stopping position A (30 degrees). Therefore, when the crankshaft rotates counterclockwise, the optimal stopping position A (30 degrees) is closest to the first current angle position.

[0060] Step 130: Determine a target angle based on the first current angle position and the target optimal parking position.

[0061] In some implementations, the range extender controller 100 may calculate the difference between the first current angle position and the target optimal parking position to obtain the target angle.

[0062] For example, assuming that the first current angle position is 95 degrees and the target optimal parking position is 105 degrees, the target angle is 10 degrees (105-95=10 degrees).

[0063] Step 140: Determine a target stop cycle required for the engine to stop from a preset speed based on the target angle and a plurality of preset stop cycle rotation angles.

[0064] The stop cycle rotation angle is the angle of rotation of the crankshaft of the engine 300 during the process from a preset speed to shutdown in a preset stop cycle.

[0065] In some embodiments, preset speed control gradients corresponding to different shutdown cycles are pre-configured and stored in the range extender controller 100. The range extender controller 100 can pre-calculate and store the periodic rotation angle that the crankshaft needs to experience when the engine 300 goes from a preset speed to shutdown with the preset speed control gradients corresponding to different shutdown cycles.

[0066] As an implementation manner, the range extender controller 100 may calculate, by integration, the periodic rotation angle that the crankshaft needs to experience when the engine 300 is controlled at a preset speed corresponding to different shutdown cycles from a preset speed to shutdown.

[0067] As another embodiment, the range extender controller 100 can also calculate the angle change within the shutdown cycle by the following formula, and then accumulate the angle changes of the crankshaft within multiple shutdown cycles to obtain the periodic rotation angle that the crankshaft needs to experience when the engine 300 goes from a preset speed to shutdown with a preset speed control gradient corresponding to different shutdown cycles.

[0068]

[0069] Among them, N n represents the initial speed of the nth shutdown cycle, T represents the shutdown cycle, θ n Indicates the rotation angle that the crankshaft needs to experience during the nth shutdown cycle.

[0070] For example, assuming that the preset speed is 200 revolutions per minute, a stop cycle is 10 ms.

[0071] ① Calculate the periodic rotation angle that the crankshaft needs to experience from 200prm to shutdown within one shutdown cycle (10ms, the preset speed control gradient corresponding to one shutdown cycle is -20prm / ms): 200 / 60×360×0.01=12 degrees.

[0072] ② Calculate the periodic rotation angle that the crankshaft needs to experience from 200prm to shutdown within 2 shutdown cycles (20ms, the preset speed control gradient corresponding to the 2 shutdown cycles is -10prm / ms): First calculate the angle that the crankshaft needs to experience from 200prm to 100prm within 10ms: 200 / 60×360×0.01=12 degrees;

[0073] Then calculate the angle that the crankshaft needs to go through from 100prm to 0 degrees / second in 10ms: 100 / 60×360×0.01=6 degrees;

[0074] The angles that the crankshaft needs to go through in the two stages are added together to obtain the periodic rotation angle that the crankshaft needs to go through: 12 degrees + 6 degrees = 18 degrees.

[0075] ③ Calculate the periodic rotation angle that the crankshaft needs to experience from 200prm to shutdown within 3 shutdown cycles (30ms, the preset speed control gradient corresponding to 3 shutdown cycles is -6.7prm / ms): First calculate the angle that the crankshaft needs to experience from 200prm to 133prm within 10ms: 200 / 60×360×0.01=12 degrees;

[0076] Then calculate the angle that the crankshaft needs to go through from 133prm to 66prm in 10ms: 133 / 60×360×0.01≈8 degrees;

[0077] Then calculate the angle that the crankshaft needs to go through from 133prm to 66prm within 10ms: 66 / 60×360×0.01≈4 degrees;

[0078] The angles that the crankshaft needs to go through in the three stages are added together to obtain the periodic rotation angle that the crankshaft needs to go through: 12 degrees + 8 degrees + 4 degrees = 24 degrees.

[0079] By analogy, the periodic rotation angle that the crankshaft needs to experience in the process of the engine 300 going from the preset speed to shutdown with the preset speed control gradient corresponding to different shutdown cycles is determined, as shown in Table 1.

[0080] Table 1

[0081]

[0082]

[0083] In some embodiments, Figure 3 As shown, step 140 specifically includes the following steps:

[0084] Step 141: Selecting a stop cycle rotation angle with the smallest difference from a target angle from among multiple stop cycle rotation angles, and determining it as the target cycle rotation angle.

[0085] Step 142: Determine the downtime period corresponding to the target period rotation angle as the target downtime period.

[0086] For example, as shown in Table 1, assuming that the target angle is 25 degrees, the difference between the target angle and the periodic rotation angle corresponding to one downtime cycle is 13 degrees (25-12=13), the difference between the target angle and the periodic rotation angle corresponding to two downtime cycles is 7 degrees (25-18=7), the difference between the target angle and the periodic rotation angle corresponding to three downtime cycles is 1 degree (25-24=1), the difference between the target angle and the periodic rotation angle corresponding to four downtime cycles is 5 degrees (25-30=5), and the periodic rotation angle with the smallest difference from the target angle is 24 degrees. Then, 24 degrees is determined as the target periodic rotation angle, and the three downtime cycles corresponding to 24 degrees are determined as the target downtime cycles.

[0087] Please continue reading Figure 2 , step 150: controlling the engine to shut down according to the target shutdown period.

[0088] In some embodiments, the range extender controller 100 controls the shutdown of the engine 300 according to the target shutdown cycle and the preset speed control gradient corresponding to the target shutdown cycle, that is, the range extender controller 100 gradually reduces the engine speed from the preset speed within the target shutdown cycle according to the preset speed control gradient corresponding to the target shutdown cycle, ensuring that the engine 300 is shut down smoothly and safely.

[0089] For example, assuming that each shutdown cycle is 10ms, the determined target shutdown cycle is 1 shutdown cycle, and the preset speed control gradient corresponding to the target shutdown cycle is -20prm / ms, the range extender controller 100 will reduce the engine speed according to the speed control gradient of -20prm / ms within the target shutdown cycle (10ms) until the engine stops.

[0090] It should be noted that the engine shutdown control is performed according to the determined target shutdown cycle, so that the angle position of the crankshaft when the engine is shut down can be closer to the target optimal shutdown position, and the piston connected to the crankshaft will also be closer to the optimal shutdown position. The closer the piston shutdown position is to the optimal shutdown position, the smaller the resistance is, which is conducive to improving the success rate of the next engine start-up, and can also improve the NVH (Noise, Vibration, and Harshness) performance of the vehicle.

[0091] In summary, the engine shutdown control method of the range extender provided by the embodiment of the present invention, when the engine speed is decelerated to a preset speed, obtains the first current angular position of the crankshaft, and based on the first current angular position, selects the target optimal stop position from the preset multiple optimal stop positions to ensure that the engine shutdown target is clear, and then determines the target angle according to the first current angular position and the clear target optimal stop position, determines the target stop cycle according to the target angle, and controls the engine shutdown according to the target stop cycle. Implementation of this method improves the accuracy of the angular position of the crankshaft when the engine is shut down, so that the piston connected to the crankshaft can also stop as close to the optimal stop position as possible. The closer the piston stop position is to the optimal stop position, the smaller the resistance is, which can improve the success rate of the next start of the vehicle and improve the NVH performance of the vehicle.

[0092] In order to avoid errors caused by unstable engine speed, such as Figure 4 As shown, step 110 specifically includes the following steps:

[0093] Step 111: When controlling the engine speed to decelerate from the idle speed to the preset speed, obtaining a first current angle position of the crankshaft.

[0094] In some embodiments, after receiving the shutdown command, the range extender controller controls the engine to perform power unloading, that is, controls the engine speed to decrease, and controls the engine torque to decrease. If the engine speed is less than the preset power unloading completion speed, and the engine torque is less than the preset power unloading completion torque, it is determined that the engine has completed power unloading, and at this time, the crankshaft speed is the idle speed. It should be noted that the idle speed refers to the lowest speed at which the engine can operate stably when there is no load.

[0095] It is understandable that before controlling the engine to stop, the engine must be controlled to unload power first, which can reduce the impact and vibration of the engine at the moment of stopping, which helps to protect the internal parts of the engine and avoid wear or damage to the engine parts caused by sudden stopping. And by reducing the power of the engine, the deceleration process of the engine can be controlled more finely, ensuring that the engine maintains a smooth speed change when it stops, thereby improving the controllability and reliability of the engine shutdown process.

[0096] In some embodiments, the range extender controller may control the engine speed to decelerate from the idle speed to a preset speed in the following two ways.

[0097] The first type: the range extender controller 100 can control the torque of the generator to reduce the engine speed from the idle speed to the preset speed. Specifically, the following steps may be included: obtaining the current speed of the engine in real time; obtaining the generator braking torque value corresponding to the current speed of the engine from a preset comparison table; and regulating the torque of the generator in real time according to the generator braking torque value to reduce the engine speed from the idle speed to the preset speed.

[0098] Among them, the preset comparison table includes multiple groups of generator braking torques corresponding to the crankshaft speeds, as shown in Table 2.

[0099] Table 2

[0100] Speed Generator braking torque 800prm -20N·m 700prm -18N·m 600prm -16N·m 500prm -14N·m 400prm -12N·m 300prm -10N·m

[0101] The second type: the range extender controller 100 can control the generator to reduce speed at a generator speed reduction gradient value corresponding to a preset speed so as to reduce the engine speed from the idle speed to the preset speed.

[0102] In order to avoid the situation where the accuracy of the crankshaft angle position reaching the target optimal stop position is still low when the engine is stopped according to the target stop cycle due to the existence of two optimal stop positions that are far apart, such as Figure 5 As shown, if the angle between two adjacent optimal stopping positions among the multiple optimal stopping positions is greater than the angle threshold, the following steps are specifically included before step 111:

[0103] Step 160: At idle speed, obtain a second current angle position of the crankshaft in real time.

[0104] Step 170: Compare the second current angle position with the preset shutdown starting angle range to obtain a comparison result.

[0105] Step 180: According to the comparison result, confirm that the second current angle position is within a preset angle range.

[0106] In a feasible implementation, one or more preset stop start angle ranges are stored in the range extender controller 100. When the angle position of the crankshaft at the idle speed rotates to one of the stop start angle ranges, it can be confirmed that the second current angle position of the crankshaft is within the preset angle range. The preset angle range can be obtained by reverse calculation based on the optimal stop position.

[0107] It is understandable that the angle change experienced by the crankshaft during the deceleration from the idle speed to the preset speed is determined based on the shutdown torque curve or the shutdown speed curve. Therefore, when the shutdown torque curve or the shutdown speed curve is determined, the angle of the crankshaft during the deceleration from the idle speed to the preset speed can be known. If the shutdown angle range of the crankshaft during shutdown is known, the angle interval range that the second current angle position of the crankshaft should be at the idle speed can be reversely calculated.

[0108] Assume that when the engine decelerates from idle speed to the preset speed, the angle position of the crankshaft is required to be within the range of 0 to 45 degrees, the idle speed of the crankshaft is 800prm, and the preset speed is 200prm. According to the shutdown torque curve or the shutdown speed curve, it is calculated that the total angle change that the crankshaft needs to experience when decelerating from 800prm to 200prm is 360 degrees. In order to make the angle position of the crankshaft within the range of 0 to 45 degrees when the engine decelerates to the preset speed, it is necessary to control the engine to decelerate from the idle speed when the engine is at idle speed and the angle position of the crankshaft is within the range of 0 to 45 degrees.

[0109] It should be noted that a dual Hall sensor may be provided in the engine to detect the angular position signal of the crankshaft, and the dual Hall sensor generates two rising or falling edge signals to enable accurate signal detection in each cycle. When the engine is running at idle speed (usually the idle speed is between 900-1000rpm), the rotation angle of the crankshaft in each shutdown cycle is within a range (approximately 54-60 degrees).

[0110] Through the above steps 160-180, it can be ensured that the angle position of the crankshaft is controlled within a certain range when the engine speed decelerates to the preset speed. That is, by controlling the initial stop position of the crankshaft in the idle state to be within the preset angle range, it can be ensured that when the engine decelerates to the preset speed, the angle position of the crankshaft is within a reasonable range and bypasses the farthest optimal stop position, ensuring that the engine is subsequently controlled to stop according to the determined target stop cycle, so that the engine crankshaft stops at the ideal stop position.

[0111] In order to execute the corresponding steps in the above embodiments and various possible methods, a method for implementing an engine shutdown control device is provided below. Figure 6, is a functional module diagram of an engine shutdown control device provided by an embodiment of the present invention. It should be noted that the basic principle and technical effects of the engine shutdown control device provided by this embodiment are the same as those of the above-mentioned embodiments. For the sake of brief description, for parts not mentioned in this embodiment, reference can be made to the corresponding contents in the above-mentioned embodiments. The engine shutdown control device 400 includes a current angle position acquisition module 410, a target angle determination module 420, a target shutdown cycle acquisition module 430 and a shutdown control module 440, wherein:

[0112] The current angle position acquisition module 410 is used to acquire a first current angle position of the crankshaft when the engine speed is decelerated to a preset speed; wherein the preset speed is less than the idle speed of the engine.

[0113] The target angle determination module 420 is used to select a target optimal parking position from a plurality of preset optimal parking positions based on the first current angle position; and determine a target angle based on the first current angle position and the target optimal parking position.

[0114] The target shutdown cycle acquisition module 430 is used to determine the target shutdown cycle required for the engine to stop from a preset speed based on the target angle and multiple preset shutdown cycle rotation angles; wherein the shutdown cycle rotation angle is the angle of rotation of the crankshaft during the process of the engine from a preset speed to shutdown in a preset shutdown cycle.

[0115] The shutdown control module 440 is used to control the engine shutdown according to the target shutdown period.

[0116] Optionally, the shutdown control module 430 is specifically configured to select a shutdown cycle rotation angle with the smallest difference from a target angle from multiple shutdown cycle rotation angles, and determine it as the target cycle rotation angle; and determine the shutdown cycle corresponding to the target cycle rotation angle as the target shutdown cycle.

[0117] Optionally, the current angle position acquisition module 410 is specifically used to control the engine speed to decelerate from an idle speed to a preset speed.

[0118] Optionally, the engine stop control device 400 further includes an initial stop position determination module, wherein:

[0119] The initial stopping position determination module is used to: if the angle between two adjacent optimal stopping positions among multiple optimal stopping positions is greater than the angle threshold, at idle speed, obtain the second current angle position of the crankshaft in real time; compare the second current angle position with the preset stopping starting angle range to obtain a comparison result; and confirm, based on the comparison result, that the second current angle position is within the preset angle range.

[0120] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices and modules can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here.

[0121] In several embodiments provided by the present invention, the coupling between modules may be electrical, mechanical or other forms of coupling.

[0122] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of software functional modules.

[0123] Please refer to Figure 7 , is a block diagram of a range extender 500 provided in an embodiment of the present invention. The range extender 500 includes a memory 510, a processor 520, and a communication module 530. The memory 510, the processor 520, and the communication module 530 are electrically connected to each other directly or indirectly to achieve data transmission or interaction. For example, these components can be electrically connected to each other through one or more communication buses or signal lines.

[0124] The memory 510 is used to store programs or data. The memory 510 may be, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), etc.

[0125] The processor 520 is used to read / write data or programs stored in the memory and execute corresponding functions. For example, when the computer program stored in the memory 510 is executed by the processor 520, the engine shutdown control method disclosed in the above embodiments can be implemented.

[0126] The communication module 530 is used to establish a communication connection between the range extender 500 and the vehicle controller through the network, and is used to send and receive data through the network.

[0127] It should be understood that Figure 7 The structure shown is only a schematic diagram of the range extender. The range extender may also include Figure 7 More or fewer components may be shown. Figure 7 Each component shown in the figure can be implemented by hardware, software or a combination thereof.

[0128] An embodiment of the present invention further provides a car, which includes the above-mentioned range extender.

[0129] In several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present invention. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and a module, a program segment or a part of the code contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0130] If the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0131] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for controlling engine shutdown of a range extender, characterized in that: include: When the engine speed is decelerated to a preset speed, a first current angle position of the crankshaft is obtained; wherein the preset speed is less than the idle speed of the engine; Based on the first current angular position, selecting a target optimal stopping position from a plurality of preset optimal stopping positions; Determining a target angle based on the first current angle position and the target optimal parking position; Based on the target angle and a plurality of preset stop cycle rotation angles, a target stop cycle required for the engine to stop from the preset speed is determined; wherein the stop cycle rotation angle is the angle of rotation of the crankshaft during the process of the engine stopping from the preset speed in the preset stop cycle; The engine is controlled to be stopped according to the target stop period.

2. The method according to claim 1, characterized in that The step of determining a target stop cycle required for the engine to stop from the preset speed based on the target angle and a plurality of preset stop cycle rotation angles includes: Selecting a stop cycle rotation angle having the smallest difference with the target angle from the plurality of stop cycle rotation angles, and determining the stop cycle rotation angle as the target cycle rotation angle; The downtime period corresponding to the target period rotation angle is determined as the target downtime period.

3. The method according to claim 1, characterized in that The engine speed is reduced to a preset speed, comprising: The engine speed is controlled to be decelerated from an idle speed to a preset speed.

4. The method according to claim 3, characterized in that If the angle between two adjacent optimal stopping positions among the plurality of optimal stopping positions is greater than the angle threshold, before controlling the engine speed to decelerate from the idle speed to the preset speed, the method further includes: At idle speed, obtaining a second current angle position of the crankshaft in real time; Comparing the second current angle position with a preset stop start angle range to obtain a comparison result; According to the comparison result, it is confirmed that the second current angle position is within a preset angle interval.

5. An engine shutdown control device, characterized in that: include: A current angle position acquisition module, used to acquire a first current angle position of the crankshaft when the engine speed is decelerated to a preset speed; wherein the preset speed is less than the idle speed of the engine; a target angle determination module, configured to select a target optimal stopping position from a plurality of preset optimal stopping positions based on the first current angle position; and determine a target angle based on the first current angle position and the target optimal stopping position; A target stop cycle acquisition module is used to determine the target stop cycle required for the engine to stop from the preset speed based on the target angle and a plurality of preset stop cycle rotation angles; wherein the stop cycle rotation angle is the angle of rotation of the crankshaft during the process of the engine stopping from the preset speed with the preset stop cycle; A shutdown control module is used to control the engine to shut down according to the target shutdown period.

6. The device according to claim 5, characterized in that The step of determining a target stop cycle required for the engine to stop from the preset speed based on the target angle and a plurality of preset stop cycle rotation angles includes: Selecting a stop cycle rotation angle having the smallest difference with the target angle from the plurality of stop cycle rotation angles, and determining the stop cycle rotation angle as the target cycle rotation angle; The downtime period corresponding to the target period rotation angle is determined as the target downtime period.

7. The device according to claim 5, characterized in that The engine speed is reduced to a preset speed, comprising: The engine speed is controlled to be decelerated from an idle speed to a preset speed.

8. The device according to claim 7, characterized in that The device also includes an initial stop position determination module; The initial stop position determination module is used to: If the angle between two adjacent optimal stopping positions among the plurality of optimal stopping positions is greater than the angle threshold, At idle speed, obtaining a second current angle position of the crankshaft in real time; Comparing the second current angle position with a preset stop start angle range to obtain a comparison result; According to the comparison result, it is confirmed that the second current angle position is within a preset angle interval.

9. A range extender, characterized in that: The invention comprises a processor and a memory, wherein the memory stores a computer program executable by the processor, and when the computer program is executed by the processor, the engine shutdown control method according to any one of claims 1 to 4 is implemented.

10. An automobile, characterized in that: Comprising the range extender as claimed in claim 9.

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