Method, device, electronic device and storage medium for controlling engine speed of vehicle

Abstract

The present application provides a method, device, electronic device and storage medium for controlling the engine speed of an automobile. The method includes: identifying the current state of the vehicle's power battery; when the current state of the vehicle's power battery meets a preset condition, determining whether the current required power of the vehicle is greater than a preset power threshold; when the current required power of the vehicle is greater than the preset power threshold, obtaining a first speed according to the current required power of the vehicle and the best operating curve of the range extender; obtaining a second speed, where the second speed is the lowest speed corresponding to the engine at the current vehicle speed of the vehicle preset in advance; and determining the target speed of the engine at the current moment according to the first speed and the second speed. It can avoid large fluctuations in the engine speed during driving following the change of the vehicle's required power, reduce the power response time, and improve the power performance.

Description

Technical Field

[0001] This application relates to the technical field of automotive engine control, and particularly to a method, device, electronic device, and storage medium for controlling the engine speed of an automobile. Background Art

[0002] Due to the performance of automotive power batteries being affected by environmental temperature and their own battery levels, it is difficult to maintain the best state. Therefore, how to maintain a stable output of power performance in the full time domain and full geographical area is one of the key technologies in current vehicle development. Summary of the Invention

[0003] The main purpose of the embodiments of this application is to propose a method, device, electronic device, and storage medium for controlling the engine speed of an automobile. When the current state of the automotive power battery deviates from the best state and the current demand power of the automobile is greater than the preset power threshold, it is possible to determine the target speed of the engine according to the extended-range optimal operating curve and the minimum engine speed corresponding to the current vehicle speed set in advance, avoiding large fluctuations in the engine speed following the change of the vehicle demand power during driving, reducing the power response time, and improving the power performance.

[0004] To achieve the above purpose, the first aspect of the embodiments of this application proposes a method for controlling the engine speed of an automobile, the method comprising:

[0005] Identifying the current state of the automotive power battery;

[0006] When the current state of the automotive power battery meets the preset conditions, determining whether the current demand power of the automobile is greater than the preset power threshold;

[0007] When the current demand power of the automobile is greater than the preset power threshold, obtaining a first speed according to the current demand power of the automobile and the extended-range optimal operating curve, where the extended-range optimal operating curve is a curve connecting the lowest fuel consumption points on each equal-power curve of the automobile in the extended-range mode, and the first speed is the speed of the engine at the lowest fuel consumption point;

[0008] Obtaining a second speed, where the second speed is the minimum speed of the engine corresponding to the current vehicle speed of the automobile set in advance;

[0009] Determining the target speed of the engine at the current moment according to the first speed and the second speed.

[0010] In some embodiments, the identifying the current state of the automotive power battery includes:

[0011] Obtaining the current battery level of the automotive power battery;

[0012] When the current battery level does not exceed a preset battery level threshold, it is determined that the current state of the vehicle power battery meets a preset condition.

[0013] In some embodiments, the identifying the current state of the vehicle power battery includes:

[0014] Obtaining the current discharge power of the vehicle power battery;

[0015] When the current discharge power does not exceed a power setting value, it is determined that the current state of the vehicle power battery meets a preset condition.

[0016] In some embodiments, when the current state of the vehicle power battery meets a preset condition, determining whether the current power demand of the vehicle is greater than a preset power threshold includes:

[0017] When the current state of the vehicle power battery meets a preset condition, obtaining the current power demand of the vehicle, where the current power demand of the vehicle includes the wheel-end power demand, the accessory power, and the power generation demand power;

[0018] Comparing the current power demand of the vehicle with the preset power threshold to determine whether the current power demand of the vehicle is greater than the preset power threshold.

[0019] In some embodiments, the obtaining the second rotational speed includes:

[0020] Obtaining the current vehicle speed of the vehicle;

[0021] According to the current vehicle speed and the pre-set correspondence between the vehicle speed and the minimum engine rotational speed in the range extender mode, obtaining the second rotational speed.

[0022] In some embodiments, before obtaining the second rotational speed, the method includes:

[0023] Pre-determining the noise decibel threshold corresponding to different vehicle speeds in the range extender mode;

[0024] According to the noise decibel threshold corresponding to different vehicle speeds, determining the minimum engine rotational speed corresponding to different vehicle speeds.

[0025] In some embodiments, according to the first rotational speed and the second rotational speed, determining the target rotational speed of the engine at the current moment includes:

[0026] If the first rotational speed is greater than the second rotational speed, determining the first rotational speed as the target rotational speed of the engine at the current moment;

[0027] If the first rotational speed is not greater than the second rotational speed, determining the second rotational speed as the target rotational speed of the engine at the current moment.

[0028] To achieve the above object, a second aspect of the embodiments of the present application provides an engine speed control device for a vehicle, the device comprising:

[0029] An identification module for identifying the current state of the vehicle's power battery;

[0030] A judgment module for judging whether the current demand power of the vehicle is greater than a preset power threshold when the current state of the vehicle's power battery meets a preset condition;

[0031] A first acquisition module for obtaining a first speed according to the current demand power of the vehicle and an extended-range optimal working curve when the current demand power of the vehicle is greater than the preset power threshold, the extended-range optimal working curve being a curve formed by connecting the lowest fuel consumption points on each constant power curve of the vehicle in the extended-range mode, and the first speed being the speed of the engine at the lowest fuel consumption point;

[0032] A second acquisition module for obtaining a second speed, the second speed being the lowest speed of the engine corresponding to the current vehicle speed of the vehicle preset in advance;

[0033] A determination module for determining the target speed of the engine at the current moment according to the first speed and the second speed.

[0034] To achieve the above object, a third aspect of the embodiments of the present application provides an electronic device, the electronic device comprising a memory and a processor, the memory storing a computer program, and the processor implementing the method described in the first aspect above when executing the computer program.

[0035] To achieve the above object, a fourth aspect of the embodiments of the present application provides a computer-readable storage medium, the storage medium storing a computer program, wherein the computer program implements the method described in the first aspect above when executed by a processor.

[0036] An engine speed control method, device, electronic device and storage medium for an automobile proposed in this application. The method includes: identifying the current state of the vehicle's power battery; when the current state of the vehicle's power battery meets a preset condition, determining whether the current power demand of the vehicle is greater than a preset power threshold; when the current power demand of the vehicle is greater than the preset power threshold, obtaining a first speed according to the current power demand of the vehicle and the best operating curve for range extension. The best operating curve for range extension is a curve formed by connecting the lowest fuel consumption points on each constant power curve of the vehicle in the range-extended mode. The first speed is the speed of the engine at the lowest fuel consumption point; obtaining a second speed, which is the lowest speed preset for the engine corresponding to the current vehicle speed; determining the target speed of the engine at the current moment according to the first speed and the second speed. It can avoid large fluctuations in the engine speed following the vehicle's power demand during driving, reduce the power response time, and improve the power performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a flowchart of the engine speed control method for an automobile provided in an embodiment of this application;

[0038] Figure 2 is a flowchart of the step of identifying the current state of the vehicle's power battery provided in an embodiment of this application;

[0039] Figure 3 is another flowchart of the step of identifying the current state of the vehicle's power battery provided in an embodiment of this application;

[0040] Figure 4 is a schematic diagram of the transmission mechanism of a hybrid vehicle provided in an embodiment of this application;

[0041] Figure 5 is a flowchart of the step of determining whether the current power demand of the vehicle is greater than a preset power threshold when the current state of the vehicle's power battery meets a preset condition provided in an embodiment of this application;

[0042] Figure 6 is a flowchart of the step of obtaining the first speed according to the best operating curve for range extension when the current power demand of the vehicle is greater than the preset power threshold provided in an embodiment of this application;

[0043] Figure 7 is a flowchart of the engine speed control for an automobile provided in an embodiment of this application;

[0044] Figure 8 is a schematic diagram of the structure of the engine speed control device for an automobile provided in an embodiment of this application;

[0045] Figure 9 is a schematic diagram of the hardware structure of the electronic device provided in an embodiment of this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0047] It should be noted that although the functional modules are divided in the device schematic diagram and the logical sequence is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order from the module division in the device or the sequence in the flowchart. The terms "first", "second", etc. in the description, claims and the above-mentioned drawings are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0049] Due to the assistance of the power battery, the strong power performance has become one of the highlight performances of hybrid vehicles. Generally, in order to maintain the stable output of the power performance, it is necessary to keep the power battery in the best state all the time. For example, when the battery temperature is high, the battery needs to be cooled; when the battery temperature is too low, the battery needs to be heated; when the battery power is insufficient, the charging power can be increased; when the battery power is too high, the battery can be discharged partially; through these methods, the battery temperature and power can be controlled within a reasonable range, and the performance of the power battery can be in the best state. However, since the performance of the power battery is affected by the ambient temperature and its own power, it is difficult to always maintain the best state; at the same time, in some cases, it is difficult to improve or recover the battery performance in a short time; therefore, when the performance of the power battery deviates from the best state, it is necessary to control the engine speed to ensure the power performance of the vehicle.

[0050] Currently, during driving, the engine speed is likely to fluctuate significantly following the wheel-end demand. For example, when the accelerator is released at high speed, due to the decrease in the wheel-end demand power, the engine requested speed decreases; when the accelerator is pressed again to accelerate, the engine requested speed needs to increase again, but it takes a certain amount of time to establish the requested speed, and it is easy to have the problem of untimely power response.

[0051] Based on this, an engine speed control method for an automobile is proposed in an embodiment of the present application. When the current state of the vehicle's power battery deviates from the optimal state and the current demand power of the vehicle is greater than a preset power threshold, the target speed of the engine can be determined according to the extended-range optimal working curve and the minimum engine speed corresponding to the preset current vehicle speed, avoiding large fluctuations in the engine speed during driving following the change of the vehicle's demand power, reducing the power response time, and improving the power performance.

[0052] Referring to Figure 1 , Figure 1 is a flowchart of the engine speed control method for an automobile provided in an embodiment of the present application, Figure 1 and the method in

[0053] Step S101, identify the current state of the vehicle's power battery.

[0054] In an embodiment of the present application, since when the vehicle's power battery is in the optimal state, the power response problem can be handled by the motor, and since the motor has a fast processing rate, there is basically no problem of slow power response. Only when the vehicle's power battery deviates from the optimal state, the engine is needed to handle the power response problem. At this time, it is necessary to control the engine speed to reduce the power response time and improve the power performance. Therefore, it is necessary to first identify the current state of the vehicle's power battery. If it is identified that the vehicle's power battery is currently in the optimal state, the control of the engine speed proposed in the present application is not executed. If it is identified that the vehicle's power battery currently deviates from the optimal state, that is, it is identified that the vehicle's power battery meets the preset conditions, then step S102 is continued to be executed.

[0055] Referring to Figure 2 , Figure 2 is a flowchart of the steps for identifying the current state of the vehicle's power battery provided in an embodiment of the present application, including but not limited to steps S201 to S202.

[0056] Step S201, obtain the current power of the vehicle's power battery;

[0057] Step S202, when the current power does not exceed the preset power threshold, determine that the current state of the vehicle's power battery meets the preset conditions.

[0058] In an embodiment of the present application, the current state of the vehicle's power battery can be judged whether it meets the preset conditions, that is, whether the performance of the vehicle's power battery is in the optimal state, through the current power of the vehicle's power battery. If the current power does not exceed the preset power threshold, it is determined that the performance of the vehicle's power battery deviates from the optimal state.

[0059] Exemplarily, the preset power threshold is K0 Ah, and the current power of the vehicle's power battery obtained is K1 Ah. At this time, the current power K1 Ah is compared with the preset power threshold K0 Ah. If K1 ≤ K0, it is determined that the current state of the vehicle's power battery meets the preset conditions, that is, the performance of the vehicle's power battery deviates from the optimal state. If K1 > K0, it is determined that the current state of the vehicle's power battery does not meet the preset conditions, that is, the performance of the vehicle's power battery is in the optimal state.

[0060] It should be noted that the current power of the vehicle's power battery can also be represented by the remaining power of the vehicle's power battery. In the embodiments of the present application, the remaining power (current power) of the power battery can be viewed on the dashboard of the vehicle, or the remaining power (current power) of the vehicle's power battery can be obtained by other means. The embodiments of the present application do not specifically limit the method for obtaining the current power of the vehicle's power battery.

[0061] Refer to Figure 3 , Figure 3 is another flowchart of steps for identifying the current state of the vehicle's power battery provided by the embodiments of the present application, including but not limited to steps S301 to S302.

[0062] Step S301, obtain the current discharge power of the vehicle's power battery;

[0063] Step S302, when the current discharge power does not exceed the power set value, determine that the current state of the vehicle's power battery meets the preset conditions.

[0064] In the embodiments of the present application, the current state of the vehicle's power battery can be judged by the current discharge power of the vehicle's power battery, that is, whether the performance of the vehicle's power battery is in the optimal state. If the current discharge power does not exceed the power set value, it is determined that the performance of the power battery deviates from the optimal state. The discharge power of the power battery affects the performance of the electric vehicle such as acceleration, cruising range, and driving smoothness.

[0065] Exemplarily, the power set value is P0 kw, and the current discharge power of the vehicle's power battery obtained is P1 kw. At this time, the current discharge power P1 kw is compared with the power set value P0 kw. If P1 ≤ P0, it is determined that the current state of the vehicle's power battery meets the preset conditions, that is, the performance of the vehicle's power battery deviates from the optimal state. If P1 > P0, it is determined that the current state of the vehicle's power battery does not meet the preset conditions, that is, the performance of the vehicle's power battery is in the optimal state.

[0066] It should be noted that in the embodiments of the present application, the current discharge power can be calculated from the discharge voltage and current of the power battery, or the current discharge power of the vehicle's power battery can be obtained by other means. The embodiments of the present application do not specifically limit the method for obtaining the current discharge power of the vehicle's power battery.

[0067] Step S102: When the current state of the vehicle's power battery meets the preset conditions, determine whether the current required power of the vehicle is greater than the preset power threshold.

[0068] In the embodiments of the present application, through Figure 2 or Figure 3 After determining that the current state of the vehicle's power battery meets the preset conditions, it is necessary to further determine whether the current required power of the vehicle is greater than the preset power threshold. Only when the current state of the vehicle's power battery meets the preset conditions and the current required power of the vehicle is greater than the preset power threshold, the control of the engine speed is executed. If the current state of the vehicle's power battery meets the preset conditions, but the current required power of the vehicle is not greater than the preset power threshold, the control of the engine speed is not executed.

[0069] It should be noted that in the embodiments of the present application, when the current state of the vehicle's power battery meets the preset conditions and the current required power of the vehicle is greater than the preset power threshold, the vehicle will automatically enter the range extender mode.

[0070] Refer to Figure 4 , Figure 4 is a schematic diagram of the transmission mechanism of the hybrid vehicle provided by the embodiments of the present application. As shown by Figure 4 , when the brake B is closed (the sun gear is combined with the housing), or the clutch C1 is closed (the ring gear is combined with the sun gear), the engine can achieve two different direct drive modes with different transmission ratios to drive the wheel ends. When both the brake B and the clutch C1 are open, the engine drives the wheel ends based on the range extender mode. Since the range extender mode has the advantages of adjustable speed and greater reserve power, the range extender mode has become the preferred drive mode for the vehicle's power performance. The embodiments of the present application improve the vehicle's power performance from the perspective of optimizing the control mode.

[0071] Refer to Figure 5 , Figure 5 is a flowchart of the steps for determining whether the current required power of the vehicle is greater than the preset power threshold when the current state of the vehicle's power battery meets the preset conditions provided by the embodiments of the present application, including but not limited to steps S501 to S502.

[0072] Step S501: When the current state of the vehicle's power battery meets the preset conditions, obtain the current required power of the vehicle. The current required power of the vehicle includes the wheel end required power, the accessory power, and the power generation required power;

[0073] Step S502: Compare the current required power of the vehicle with the preset power threshold to determine whether the current required power of the vehicle is greater than the preset power threshold.

[0074] In the embodiments of the present application, when through Figure 2 or Figure 3When it is determined that the current state of the vehicle power battery meets the preset conditions, that is, when the performance of the vehicle power battery deviates from the optimal state, it is necessary to further obtain the current demand power of the vehicle, including obtaining the current wheel-end demand power, accessory power, power generation demand power, etc. of the vehicle. Then, compare the current demand power of the vehicle with the preset power threshold to determine whether the current demand power of the vehicle is greater than the preset power threshold.

[0075] Exemplarily, the preset power threshold is Pkw, and the currently obtained demand power of the vehicle is P1kw. If P1 ≤ P, it is determined that the current demand power of the vehicle is not greater than the preset power threshold, and step S103 is not entered. If P1 > P, it is determined that the current demand power of the vehicle is greater than the preset power threshold, and step S103 is entered.

[0076] Step S103, when the current demand power of the vehicle is greater than the preset power threshold, obtain the first rotational speed according to the current demand power of the vehicle and the optimal operating curve of the range extender. The optimal operating curve of the range extender is a curve formed by connecting the lowest fuel consumption points on each constant power curve of the vehicle in the range extender mode. The first rotational speed is the rotational speed of the engine at the lowest fuel consumption point.

[0077] In the embodiment of the present application, when the current state of the vehicle power battery meets the preset conditions and the current demand power of the vehicle is greater than the preset power threshold, the vehicle will automatically enter the range extender mode. At this time, the first rotational speed can be obtained according to the optimal operating curve of the range extender and the current demand power of the vehicle. Among them, the optimal operating curve of the range extender is a curve formed by connecting the lowest fuel consumption points on each constant power curve of the vehicle in the range extender mode. The abscissa of the optimal operating curve of the range extender is the engine rotational speed, and the ordinate is the engine torque. According to the engine power formula P = n * M / 9550, it can be known that under the condition of constant power, the engine rotational speed and the engine torque are inversely proportional, that is, the greater the engine rotational speed, the smaller the engine torque. In the embodiment of the present application, through the optimal operating curve of the range extender, the rotational speed of the engine at the current demand power of the vehicle, that is, the first rotational speed, can be obtained.

[0078] In the embodiment of the present application, when the current state of the vehicle power battery meets the preset conditions and the current demand power of the vehicle is greater than the preset power threshold, the optimal operating curve of the range extender can be determined according to the universal characteristics of the engine, and then the first rotational speed can be determined according to the current demand power of the vehicle and the optimal operating curve of the range extender.

[0079] Exemplarily, for the extended-range optimal operating curve, on the constant-power curve in the extended-range mode, the lowest fuel consumption point on this curve is taken, these lowest fuel consumption points are connected, and the optimal operating route is determined based on the analysis of the final result. Before finding the extended-range optimal operating curve, it is necessary to project the engine's universal characteristic data onto the engine efficiency map through the speed increaser and calculate the universal characteristic data in the extended-range mode. After passing through the speed increaser, the engine's universal characteristics increase in speed and decrease in torque. The engine's brake-specific fuel consumption (BSFC) is divided by the speed increaser efficiency η to obtain the engine's universal characteristic data at the output end of the speed increaser. The external characteristic in the extended-range mode is jointly restricted by the external characteristic at the output end of the speed increaser and the engine's external characteristic. The intersection data of the two external characteristics is taken as the external characteristic in the extended-range mode. After obtaining the external characteristic data in the extended-range mode, the engine operating speed range and output torque range in the extended-range mode can be determined. According to the power calculation formula: P = n * M / 9550, calculate the maximum power and minimum power that can be provided in the extended-range mode, and vectorize and reserve the power according to the calculation accuracy requirements. Then, the brake-specific fuel consumption (BSFC) at the output end of the speed increaser and the engine's efficiency data are respectively interpolated two-dimensionally according to the external characteristic grid in the extended-range mode to obtain a new brake-specific fuel consumption (BSFC) matrix at the speed increaser end and an engine efficiency matrix. After that, the brake-specific fuel consumption at the same coordinates is divided by the engine efficiency respectively, and the brake-specific fuel consumption APU_BSFC matrix at the corresponding coordinates in the extended-range mode can be obtained. So far, the universal characteristic data in the extended-range mode has been calculated.

[0080] To avoid calculation null values when finding the minimum fuel consumption point, it can be considered to calculate the corresponding torque according to each integer speed in the extended-range mode, reconstitute the new matrix dimension, and interpolate and expand the brake-specific fuel consumption (BSFC) in the extended-range mode according to the integer speed and the corresponding torque. Then, iterate according to the output power vector in the extended-range mode to find the minimum fuel consumption value at each power point and mark the coordinates of each fuel consumption point.

[0081] After the selection of the minimum fuel consumption points is completed, it is also necessary to select a suitable operating range in the extended-range mode according to the actual vehicle requirements. Plot the brake-specific fuel consumption (g / kwh) in the extended-range mode and the output power (kw) on one graph. After multiplying the brake-specific fuel consumption (g / kwh) in the extended-range mode by the output power (kw), the hourly fuel consumption rate (g / h) in the extended-range mode is obtained, and it is plotted with the output power on one graph. In this way, the extended-range optimal operating curve can be plotted, and then based on the current required power of the vehicle, the engine speed at the current required power of the vehicle is found from the extended-range optimal operating curve, that is, the first speed.

[0082] Step S104, obtain the second speed, where the second speed is the lowest speed preset for the engine corresponding to the current vehicle speed.

[0083] In the embodiments of the present application, considering that during the driving of an automobile, for example, when the accelerator pedal is released at high speed, the required power at the wheel end decreases, resulting in a decrease in the engine speed request. When the accelerator pedal is pressed again to accelerate, it will cause an increase in the engine speed request. That is, if only the required power is considered, the engine speed request will change relatively frequently, and it takes a long time for the response to change from a lower speed to a higher speed or from a higher speed to a lower speed. Therefore, in the embodiments of the present application, the minimum engine speed corresponding to different vehicle speeds in the extended-range mode of the automobile is also preset in advance. For example, in the extended-range mode of the automobile, when the vehicle speed is V1, the corresponding minimum engine speed is N1; when the vehicle speed is V2, the corresponding minimum engine speed is N2. In this way, the minimum engine speed corresponding to different vehicle speeds in the extended-range mode of the automobile is set.

[0084] Refer to Figure 6 , Figure 6 is a flowchart of the steps for obtaining the second speed provided by the embodiments of the present application, including but not limited to steps S601 to S602.

[0085] Step S601, obtain the current vehicle speed of the automobile;

[0086] Step S602, obtain the second speed according to the current vehicle speed and the corresponding relationship between the vehicle speed and the minimum engine speed of the automobile in the extended-range mode preset in advance.

[0087] In the embodiments of the present application, after determining the first speed according to the current required power of the automobile and the extended-range optimal working curve, the minimum engine speed corresponding to the current vehicle speed of the automobile preset in advance can be further obtained as the second speed according to the current vehicle speed. Then, a larger speed is selected from the first speed and the second speed as the final target speed.

[0088] Specifically, in the embodiments of the present application, the noise decibel thresholds corresponding to different vehicle speeds in the extended - range mode can be determined in advance, and then, according to the noise decibel thresholds corresponding to different vehicle speeds, the minimum engine speed corresponding to different vehicle speeds can be determined. For example, it is determined in advance that the noise decibel threshold is AdB when the vehicle speed is V1 in the extended - range mode, and the noise decibel threshold is BdB when the vehicle speed is V2. At this time, when the vehicle speed is V1, the engine speed is slowly increased. Since the noise decibel of the vehicle will increase as the engine speed increases, when it is detected that the noise decibel increases to the pre - set noise decibel threshold A, the increase in the engine speed is stopped. The engine speed at the current moment is obtained, and the engine speed at the current moment is determined as the minimum engine speed under the condition of the vehicle speed V1. Similarly, when the vehicle speed is V2, the engine speed is slowly increased. When it is detected that the noise decibel increases to the pre - set noise decibel threshold B, the increase in the engine speed is stopped, the engine speed at the current moment is obtained, and the engine speed at the current moment is determined as the minimum engine speed under the condition of the vehicle speed V2. In this way, the minimum engine speeds corresponding to different vehicle speeds in the extended - range mode can be determined.

[0089] Exemplarily, in the extended - range mode, when the vehicle speed of the vehicle is 80 km / h, the corresponding noise decibel is set to 65 dB; therefore, when the vehicle speed of the vehicle is 80 km / h, the engine speed is slowly increased until the noise decibel reaches 65 dB. The engine speed at the current moment is obtained as N1, and the engine speed N1 at the current moment is determined as the minimum engine speed corresponding to the vehicle speed of 80 km / h. Similarly, when the vehicle speed of the vehicle is 100 km / h, the corresponding noise decibel is set to 68 dB; therefore, when the vehicle speed of the vehicle is 100 km / h, the engine speed is slowly increased until the noise decibel reaches 68 dB. The engine speed at the current moment is obtained as N2, and the engine speed N2 at the current moment is determined as the minimum engine speed corresponding to the vehicle speed of 100 km / h. Similarly, when the vehicle speed of the vehicle is 120 km / h, the corresponding noise decibel is set to 70 dB; therefore, when the vehicle speed of the vehicle is 120 km / h, the engine speed is slowly increased until the noise decibel reaches 70 dB. The engine speed at the current moment is obtained as N3, and the engine speed N3 at the current moment is determined as the minimum engine speed corresponding to the vehicle speed of 120 km / h.

[0090] It can be understood that by presetting the noise decibel thresholds corresponding to different vehicle speeds in the extended - range mode to determine the minimum engine speeds corresponding to different vehicle speeds, the embodiments of the present application can ensure that the set minimum engine speeds do not affect the NVH performance of the vehicle.

[0091] Step S105, determine the target engine speed at the current moment according to the first speed and the second speed.

[0092] In the embodiment of the present application, after obtaining the first rotational speed and the second rotational speed, the first rotational speed and the second rotational speed are compared. If the first rotational speed is greater than the second rotational speed, the first rotational speed is determined as the target rotational speed of the engine at the current moment; if the first rotational speed is not greater than the second rotational speed, the second rotational speed is determined as the target rotational speed of the engine at the current moment. That is, a larger rotational speed is selected from the first rotational speed and the second rotational speed as the target rotational speed, thereby reducing the power response time. For example, the current rotational speed of the engine is V0. When the accelerator pedal is released quickly at high speed, since the required power at the wheel end decreases, the rotational speed request of the engine will decrease. According to the current required power of the vehicle and the best operating curve of the range extender, the first rotational speed is determined as V1, and according to the current vehicle speed, the lowest rotational speed corresponding to the current vehicle speed of the vehicle is obtained as V2. At this time, since V2 > V1, the time taken to reduce the engine rotational speed from V0 to V2 is shorter than the time taken to reduce the engine rotational speed from V0 to V1. Therefore, by determining the target rotational speed of the engine as V2, the power response time can be shortened and the power performance can be improved. Similarly, after reducing the engine rotational speed from V0 to V2, if the accelerator pedal is pressed again to accelerate, at this time, since the required power at the wheel end increases, the rotational speed request of the engine will increase. For example, according to the current required power of the vehicle and the best operating curve of the range extender, the first rotational speed is determined as V3, that is, the engine rotational speed needs to be increased from V2 to V3. At this time, since the engine rotational speed was not reduced to V1 but to V2 during the previous response, the time taken to increase the engine rotational speed from V2 to V3 is shorter than the time taken to increase the engine rotational speed from V1 to V3. Therefore, the power response time can also be shortened and the power performance can be improved.

[0093] It can be understood that in the embodiment of the present application, the lowest engine rotational speed corresponding to different vehicle speeds is set when the vehicle is in the range extender mode so that when the current required power of the vehicle decreases, the engine rotational speed will not decrease too much. That is, when it is found that the first rotational speed determined according to the current required power of the vehicle and the best operating curve of the range extender is too small, in order not to let the engine rotational speed decrease to too small a value, a lowest engine rotational speed corresponding to the current vehicle speed is set, so that when the engine rotational speed request decreases, it does not need to decrease too much, which can shorten the decrease time. At the same time, when the engine rotational speed request increases, it does not need to start increasing from too small a value, which can also shorten the increase time, thereby shortening the power response time and improving the power performance.

[0094] It can be understood that the preset power threshold, power setting value, preset power threshold, noise decibel threshold corresponding to different vehicle speeds, and lowest engine rotational speed corresponding to different vehicle speeds in the embodiment of the present application can all be determined according to different vehicle models and prior knowledge, and the embodiment of the present application does not specifically limit these values.

[0095] Refer to Figure 7 , Figure 7It is the flowchart of the engine speed control of the vehicle provided by the embodiment of the present application, including the following steps:

[0096] Step S701: Obtain the current power of the vehicle's power battery.

[0097] Step S702: Determine whether the current power exceeds the preset power threshold.

[0098] Step S703: Obtain the current discharge power of the vehicle's power battery.

[0099] Step S704: Determine whether the current discharge power exceeds the power setting value.

[0100] Step S705: If the current power does not exceed the preset power threshold and the current discharge power does not exceed the power setting value, obtain the current required power of the vehicle.

[0101] Step S706: Determine whether the current required power of the vehicle is greater than the preset power threshold.

[0102] Step S707: If the current required power of the vehicle is greater than the preset power threshold, obtain the first speed according to the current required power of the vehicle and the best working curve of the range extender.

[0103] Step S708: Obtain the second speed, which is the lowest speed corresponding to the engine at the current vehicle speed of the vehicle preset in advance.

[0104] Step S709: Determine whether the first speed is greater than the second speed.

[0105] Step S710: If the first speed is greater than the second speed, determine the first speed as the target speed of the engine at the current moment.

[0106] Step S711: If the first speed is not greater than the second speed, determine the second speed as the target speed of the engine at the current moment.

[0107] Please refer to Figure 8 , the embodiment of the present application also provides an engine speed control device 80 for a vehicle, which can implement the above engine speed control method for the vehicle. The device includes:

[0108] An identification module 801, configured to identify the current state of the vehicle's power battery.

[0109] A judgment module 802, configured to judge whether the current required power of the vehicle is greater than the preset power threshold when the current state of the vehicle's power battery meets the preset conditions.

[0110] The first acquisition module 803 is configured to, when the current required power of the vehicle is greater than the preset power threshold, acquire a first rotational speed according to the current required power of the vehicle and the optimal operating curve of the range extender. The optimal operating curve of the range extender is a curve formed by connecting the lowest fuel consumption points on the equal-power curves of the vehicle in the range-extended mode. The first rotational speed is the rotational speed of the engine at the lowest fuel consumption point.

[0111] The second acquisition module 804 is configured to acquire a second rotational speed, where the second rotational speed is the lowest rotational speed preset for the engine corresponding to the current vehicle speed of the vehicle.

[0112] The determination module 805 is configured to determine the target rotational speed of the engine at the current moment according to the first rotational speed and the second rotational speed.

[0113] The specific implementation manner of the engine speed control device of the vehicle is basically the same as the specific embodiments of the above-mentioned engine speed control method of the vehicle, and will not be elaborated here.

[0114] An embodiment of the present application further provides an electronic device. The electronic device includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the above-mentioned engine speed control method of the vehicle is implemented. The electronic device may be any intelligent terminal including a tablet computer, an in-vehicle computer, etc.

[0115] Please refer to Figure 9 , Figure 9 which schematically shows the hardware structure of an electronic device according to another embodiment. The electronic device includes:

[0116] The processor 901 may be implemented in a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, etc., and is configured to execute relevant programs to implement the technical solutions provided by the embodiments of the present application;

[0117] The memory 902 may be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM), etc. The memory 902 may store an operating system and other application programs. When implementing the technical solutions provided by the embodiments of the present specification through software or firmware, the relevant program codes are stored in the memory 902 and are called by the processor 901 to execute the engine speed control method of the vehicle in the embodiments of the present application;

[0118] The input / output interface 903 is configured to implement information input and output.

[0119] A communication interface 904, which is used to implement the communication interaction between this device and other devices. It can achieve communication through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WI-FI, Bluetooth, etc.);

[0120] A bus 905 that transmits information between various components of the device (such as the processor 901, the memory 902, the input / output interface 903, and the communication interface 904);

[0121] Among them, the processor 901, the memory 902, the input / output interface 903, and the communication interface 904 achieve communication connections with each other inside the device through the bus 905.

[0122] The embodiment of the present application also provides a storage medium, which is a computer-readable storage medium. This storage medium stores a computer program, and when the computer program is executed by a processor, it implements the above-mentioned engine speed control method of the vehicle.

[0123] As a non-transitory computer-readable storage medium, the memory can be used to store non-transitory software programs and non-transitory computer-executable programs. In addition, the memory can include high-speed random access memory, and can also include non-transitory memory, such as at least one disk storage device, a flash memory device, or other non-transitory solid-state storage devices. In some embodiments, the memory may optionally include a memory remotely set relative to the processor, and these remote memories can be connected to the processor through a network. Examples of the above-mentioned network include but are not limited to the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.

[0124] The embodiments described in the embodiments of the present application are for more clearly illustrating the technical solutions of the embodiments of the present application, and do not constitute a limitation to the technical solutions provided by the embodiments of the present application. Those skilled in the art can know that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0125] Those skilled in the art can understand that the technical solutions shown in the figure do not constitute a limitation to the embodiments of the present application, and may include more or fewer steps than those shown in the figure, or combine some steps, or different steps.

[0126] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0127] Those of ordinary skill in the art will understand that all or some of the steps in the methods disclosed above, and the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or a suitable combination thereof.

[0128] As used in the description of the present application and the above-mentioned drawings, the terms "first", "second", "third", "fourth", etc. (if any) are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order different from those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0129] It should be understood that in the present application, "at least one (item)" means one or more, and "a plurality" means two or more. "And / or" is used to describe the association relationship of associated objects and indicates that there can be three relationships. For example, "A and / or B" can mean: only A exists, only B exists, and both A and B exist at the same time. Among them, A and B can be singular or plural. The character " / " generally means that the associated objects before and after are in an "or" relationship. "At least one (one) of the following" or a similar expression means any combination of these items, including any combination of single items (ones) or plural items (ones). For example, at least one (one) of a, b, or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0130] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the above-mentioned unit division is only a logical function division, and there can be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be in electrical, mechanical, or other forms.

[0131] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0132] In addition, in each embodiment of the present application, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0133] If the integrated unit is implemented in the form of a software functional unit 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 application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present application. The foregoing storage medium includes: various media that can store programs such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs.

[0134] The preferred embodiments of the embodiments of the present application have been described above with reference to the accompanying drawings. However, this does not limit the scope of the rights of the embodiments of the present application. Any modifications, equivalent replacements, and improvements made by those skilled in the art without departing from the scope and essence of the embodiments of the present application shall fall within the scope of the rights of the embodiments of the present application.

Claims

1. A method for controlling the engine speed of an automobile, characterized in that, The method includes: Identifying the current state of the automotive power battery; When the current state of the automotive power battery meets a preset condition, determining whether the current demand power of the vehicle is greater than a preset power threshold; When the current demand power of the vehicle is greater than the preset power threshold, obtaining a first rotational speed according to the current demand power of the vehicle and an extended-range optimal operating curve, where the extended-range optimal operating curve is a curve formed by connecting the lowest fuel consumption points on each constant-power curve in the extended-range mode of the vehicle, and the first rotational speed is the rotational speed of the engine at the lowest fuel consumption point; Obtaining a second rotational speed, where the second rotational speed is the lowest rotational speed of the engine corresponding to the current vehicle speed of the vehicle preset in advance; Determining the target rotational speed of the engine at the current moment according to the first rotational speed and the second rotational speed; Wherein, when the current battery level of the automotive power battery does not exceed a preset battery level threshold, it is determined that the current state of the automotive power battery meets the preset condition; Or, when the current discharge power of the automotive power battery does not exceed a power setting value, it is determined that the current state of the automotive power battery meets the preset condition.

2. The method according to claim 1, wherein The step of when the current state of the automotive power battery meets the preset condition and determining whether the current demand power of the vehicle is greater than the preset power threshold includes: When the current state of the automotive power battery meets the preset condition, obtaining the current demand power of the vehicle, where the current demand power of the vehicle includes the wheel-end demand power, the accessory power, and the power generation demand power; Comparing the current demand power of the vehicle with the preset power threshold to determine whether the current demand power of the vehicle is greater than the preset power threshold.

3. The method according to claim 1, characterized in that, The step of obtaining the second rotational speed includes: Obtaining the current vehicle speed of the vehicle; Obtaining the second rotational speed according to the current vehicle speed and the corresponding relationship between the vehicle speed and the lowest rotational speed of the engine preset in the extended-range mode of the vehicle.

4. The method according to claim 1, wherein Before obtaining the second rotational speed, the method includes: Pre-determining the noise decibel thresholds corresponding to different vehicle speeds in the extended-range mode; Determining the lowest rotational speed of the engine corresponding to different vehicle speeds according to the noise decibel thresholds corresponding to different vehicle speeds.

5. The method according to claim 1, wherein Determining the target rotational speed of the engine at the current moment according to the first rotational speed and the second rotational speed includes: If the first rotational speed is greater than the second rotational speed, determining the first rotational speed as the target rotational speed of the engine at the current moment; If the first rotational speed is not greater than the second rotational speed, determining the second rotational speed as the target rotational speed of the engine at the current moment.

6. An engine speed control device for an automobile, characterized in that, The device includes: An identification module for identifying the current state of the automotive power battery; A judgment module for determining whether the current demand power of the vehicle is greater than a preset power threshold when the current state of the automotive power battery meets the preset condition; A first acquisition module for, when the current demand power of the vehicle is greater than the preset power threshold, obtaining a first rotational speed according to the current demand power of the vehicle and an extended-range optimal operating curve, where the extended-range optimal operating curve is a curve formed by connecting the lowest fuel consumption points on each constant-power curve in the extended-range mode of the vehicle, and the first rotational speed is the rotational speed of the engine at the lowest fuel consumption point; A second acquisition module, configured to acquire a second rotational speed, where the second rotational speed is the lowest rotational speed corresponding to the engine at the current vehicle speed of the automobile preset in advance; A determination module, configured to determine a target rotational speed of the engine at the current moment according to the first rotational speed and the second rotational speed; Wherein, when the current power of the vehicle power battery does not exceed a preset power threshold, it is determined that the current state of the vehicle power battery meets a preset condition; Alternatively, when the current discharge power of the vehicle power battery does not exceed a power setting value, it is determined that the current state of the vehicle power battery meets a preset condition.

7. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the method according to any one of claims 1 to 5 is implemented.

8. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, the method according to any one of claims 1 to 5 is implemented.

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