Creeping control method and system for electric vehicle

Abstract

The invention provides an electric automobile creeping control method which comprises the following steps: when the driving gear of an electric automobile is a forward gear or a reverse gear, detecting the depth of an accelerator pedal and the rotating speed of a motor; when the crawling function activation condition is met, the basic crawling moment of the electric vehicle is determined according to the motor rotating speed and the motor environment temperature; compensating the basic creeping moment based on the gradient and the rotating speed of the motor to obtain a corrected basic creeping moment; the brake pedal stroke is corrected according to the gradient, and a gradient corrected brake stroke is obtained; and based on the creep torque attenuation coefficient determined by the gradient correction brake stroke and the corrected basic creep torque, determining a final creep torque for performing creep control on the electric vehicle. According to the method and the device, the problems that the preset basic creeping moment of the electric vehicle creeping system is poor in adaptability on different road surfaces, and when the creeping speed is set to achieve creeping speed control, the torque adjusting fluctuation is large, and the creeping speed is overshoot are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle control, and particularly to a creep control method and system for an electric vehicle. Background Art

[0002] As a comfort configuration of traditional fuel vehicles, the creep function can greatly reduce the driving fatigue and provide a better driving experience in the condition of following vehicles in congested traffic. On traditional fuel vehicles, a non-rigid connection is achieved between the engine and the transmission system through a torsional damper or a torque converter, etc., and the connection between the transmission and the engine can be completely disconnected by controlling the transmission, so the creep control is relatively simple. Since the motor and the reducer of an electric vehicle are always rigidly connected, higher requirements are put forward for the creep control system of the electric vehicle. The creep control system of the electric vehicle must have a more perfect control strategy, more accurate torque control accuracy and jitter suppression ability to solve problems such as creep jitter, backward slipping during creep on a slope, unstable creep vehicle speed, uneven D / R shift, torque impact, etc.

[0003] Generally, there are two schemes for the current creep system of electric vehicles. The first scheme is to preset a basic creep torque, and determine the current creep torque by looking up a table based on the vehicle speed or the motor speed, and then send it to the motor to execute the torque. However, its adaptability to different road conditions is not good, and the creep vehicle speed is unstable. On a road with a certain slope, the vehicle cannot creep or even slips backward, which will bring discomfort and even safety risks to the passengers. The second scheme is a speed loop control scheme based on motor speed control. In this scheme, a creep target vehicle speed is set, and the motor output torque is adjusted through a PID controller to achieve creep vehicle speed control. However, there are disadvantages such as large torque adjustment fluctuations and overshoot of the creep vehicle speed. Summary of the Invention

[0004] The present invention provides a creep control method and system for an electric vehicle to solve the problems in the prior art that the adaptability of the preset basic creep torque of the creep system of the electric vehicle to different roads is poor, and there are large torque adjustment fluctuations and overshoot of the creep vehicle speed when setting a creep target vehicle speed to achieve creep vehicle speed control.

[0005] The present invention provides a creep control method for an electric vehicle, and the method includes the following steps: When the driving gear of the electric vehicle is in the forward gear or the reverse gear, detect the depth of the accelerator pedal and the motor speed; When the depth of the accelerator pedal and the motor speed meet the creep function activation condition, determine the basic creep torque of the electric vehicle according to the motor speed and the motor ambient temperature; Determine the slope of the current road, and compensate the basic creep torque based on the slope and the motor speed to obtain a corrected basic creep torque; Correct the braking pedal stroke according to the slope to obtain a slope-corrected braking stroke; Determine the final creep torque of the electric vehicle based on the creep torque attenuation coefficient determined by the slope-corrected braking stroke and the corrected basic creep torque, and the final creep torque is used for creep control of the electric vehicle.

[0006] In some embodiments, the creep function activation conditions include: The depth of the accelerator pedal is less than a preset depth limit value, and the motor speed is less than a preset speed limit value.

[0007] In some embodiments, determining the slope of the current road includes: Determine the longitudinal acceleration and vehicle speed increment of the electric vehicle within a preset time period; Calculate the slope of the current road according to the following formula: where, represents the longitudinal acceleration, represents the vehicle speed increment, represents the preset time period, and g represents the acceleration due to gravity.

[0008] In some embodiments, compensating the basic creep torque based on the slope and the motor speed to obtain a corrected basic creep torque includes: Determine a ramp compensation torque based on the slope and the motor speed; Take the sum of the ramp compensation torque and the basic creep torque as the corrected basic creep torque.

[0009] In some embodiments, correcting the braking pedal stroke according to the slope to obtain a slope-corrected braking stroke includes: When the slope is not 0 degrees, determine a braking stroke correction amount based on the slope; Take the difference between the braking pedal stroke and the braking stroke correction amount as the slope-corrected braking stroke; When the slope is 0 degrees, take the braking pedal stroke as the slope-corrected braking stroke.

[0010] In some embodiments, determining the final creep torque of the electric vehicle based on the creep torque attenuation system determined by the slope-corrected braking stroke and the corrected basic creep torque includes: Correct the corrected basic creep torque through the creep torque attenuation coefficient to obtain the final creep torque of the electric vehicle; Wherein, the crawling torque attenuation coefficient is determined according to the slope-corrected braking stroke and the motor speed.

[0011] The present invention also provides an electric vehicle crawling control system, which includes the following modules: A gear and motor speed control module, which is used to detect the depth of the accelerator pedal and the motor speed when the driving gear of the electric vehicle is in the forward gear or the reverse gear; A basic crawling control torque calculation module, which is used to determine the basic crawling torque of the electric vehicle according to the motor speed and the motor ambient temperature when the depth of the accelerator pedal and the motor speed meet the crawling function activation conditions; A slope-based crawling torque compensation module, which is used to determine the slope of the current road and compensate the basic crawling torque based on the slope and the motor speed to obtain a corrected basic crawling torque; A slope-based brake pedal stroke correction module, which is used to correct the brake pedal stroke according to the slope to obtain a slope-corrected braking stroke; A final crawling control torque calculation module, which is used to determine the final crawling torque of the electric vehicle based on the crawling torque attenuation coefficient determined by the slope-corrected braking stroke and the corrected basic crawling torque, and the final crawling torque is used to control the crawling of the electric vehicle.

[0012] The present invention also provides an electronic device, which includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements the electric vehicle crawling control method as described in any one of the above.

[0013] The present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the electric vehicle crawling control method as described in any one of the above.

[0014] The present invention also provides a computer program product, which includes a computer program. When the computer program is executed by a processor, it implements the electric vehicle crawling control method as described in any one of the above.

[0015] An electric vehicle creep control method and system provided by the present invention can compensate the basic creep torque of the electric vehicle by calculating the slope of the road where it is located, enabling the vehicle to maintain a stable creep speed during uphill creep and improving the driving safety in the slope congestion following vehicle condition. Secondly, by correcting the brake pedal travel signal according to the slope, it is possible to avoid the situation of vehicle backward slipping caused by the influence of the slope after the vehicle stops when lightly stepping on the brake in the uphill condition, further improving driving safety. In addition, by attenuating and correcting the creep torque based on the brake pedal travel signal corrected by the slope, the overall vehicle energy consumption in the frequent releasing and stepping on the brake condition during creep following can be reduced. The creep torque attenuation coefficient determined according to the brake travel corrected by the slope can also ensure that after the vehicle brakes and stops, the creep torque decays to zero, achieving a smooth gear shift and avoiding torque impact and vehicle jitter phenomena. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art one by one. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a schematic flow chart of the electric vehicle creep control method provided by the present invention.

[0018] Figure 2 It is a schematic architecture diagram of the electric vehicle creep control system provided by the present invention.

[0019] Figure 3 It is a schematic structural diagram of an electronic device provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention in conjunction with the drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0021] The electric vehicle creep control method provided by the present invention can be applied to an electric vehicle creep control system, and the electric vehicle creep control system can be integrated with the creep system of the electric vehicle. By detecting the depth of the accelerator pedal and the motor speed, the basic creep torque of the electric vehicle is first determined, and finally the final creep torque of the electric vehicle is calculated for assisting the creep system to perform creep control on the electric vehicle.

[0022] The electric vehicle creep control method and system of the present invention will be described below in conjunction with the accompanying drawings. Figure 1 It is a schematic flowchart of the electric vehicle creep control method provided by the present invention. As Figure 1 shown, the method includes the following steps 101 to 105.

[0023] Step 101: When the driving gear of the electric vehicle is in the forward gear or reverse gear, detect the depth of the accelerator pedal and the motor speed.

[0024] When the electric vehicle is in the state of high-voltage power-on for the whole vehicle, that is, during the startup process of the electric vehicle when the high-voltage system changes from the off state to the working state, detect the current gear of the electric vehicle, and judge whether the current electric vehicle can activate the creep function according to the gear. Here, the gears may be N gear, P gear, D gear, and R gear, which represent neutral gear, parking gear, forward gear, and reverse gear respectively.

[0025] If it is detected that the driving gear of the electric vehicle is in the neutral gear or parking gear (i.e., N gear or P gear), it means that the electric vehicle is in a stationary state of abnormal driving and cannot activate the creep function. When it is detected that the driving gear of the electric vehicle is in the forward gear or reverse gear (i.e., D gear or R gear), it means that the electric vehicle is in a normal driving state and can activate the creep function. At this time, detect the depth of the accelerator pedal and the motor speed to judge whether the activation conditions of the creep function are met.

[0026] Step 102: When the depth of the accelerator pedal and the motor speed meet the activation conditions of the creep function, determine the basic creep torque of the electric vehicle according to the motor speed and the motor ambient temperature.

[0027] In step 101, when the driving gear is in the forward gear or reverse gear, detect the depth of the accelerator pedal and the motor speed to judge whether the activation conditions of the creep function are met. The activation of the creep function generally needs to be judged according to the driving speed and the depth of the accelerator pedal of the electric vehicle. If the driving speed is too fast, creep cannot be performed. And the driving speed of the electric vehicle is generally determined according to the speed of the motor.

[0028] When it is determined that the activation conditions of the creep function are met according to the depth of the accelerator pedal and the motor speed of the electric vehicle, determine the basic creep torque of the electric vehicle according to the motor speed and the motor ambient temperature. Because the basic creep torque of the electric vehicle involves multiple factors, including the motor speed, the motor ambient temperature, and other parameters of the vehicle. There is usually a certain relationship between the torque output of the motor and the speed. At low speeds, the motor can usually provide a large torque. The motor ambient temperature will affect the efficiency, heat dissipation, and magnet performance of the motor, thereby indirectly affecting the torque output of the motor.

[0029] By detecting the motor speed and the motor ambient temperature of the current electric vehicle, the basic creep torque of the electric vehicle can be determined, and the output of the basic creep torque of the electric vehicle can also be detected by torque measuring devices.

[0030] Step 103: Determine the slope of the current road, and compensate the basic creep torque based on the slope and the motor speed to obtain the corrected basic creep torque.

[0031] When the driving gear of the electric vehicle is in the forward gear or the reverse gear, the current road being traveled may have a slope, that is, the electric vehicle may be going uphill or downhill. At this time, it is necessary to determine the slope of the current road. For example, the slope of the electric vehicle can be automatically calculated by using GPS devices, altimeters, wheel speed sensors, steering angle sensors, inertial measurement units installed on the electric vehicle or the chassis system, and combining algorithms such as machine vision.

[0032] Since the slope will affect the basic creep torque of the electric vehicle, in order to overcome the gravity component brought by the slope, it is necessary to increase or decrease the basic creep torque. Here, the basic creep torque is compensated based on the slope and the motor speed to obtain the corrected basic creep torque. For example, the basic creep torque can be updated by calculating the compensation torque based on the slope and the motor speed, or the speed correction coefficient can be calculated to correct the motor speed, and then the corrected basic creep torque can be further calculated.

[0033] Step 104: Correct the brake pedal travel according to the slope to obtain the slope-corrected brake travel.

[0034] After calculating the corrected basic creep torque through Step 103, it is also necessary to consider the overall vehicle energy consumption in the working condition of frequently releasing and stepping on the brake during creep following. Therefore, in the embodiment of the present invention, the brake pedal travel is further corrected according to the slope to obtain the slope-corrected brake travel, so as to further attenuate and correct the corrected basic creep torque by the user.

[0035] Here, the brake pedal travel signal sent by the chassis system of the electric vehicle can be detected by a sensor, and then the correction amount of the brake pedal travel is calculated according to the slope, so as to correct the brake pedal travel signal, thereby obtaining the slope-corrected brake travel.

[0036] Step 105: Determine the final creep torque of the electric vehicle based on the creep torque attenuation system determined by the slope-corrected brake travel and the corrected basic creep torque.

[0037] The slope-corrected braking stroke calculated through step 104 can be combined with the motor speed to calculate the creep torque attenuation coefficient. The creep torque attenuation coefficient is mainly related to the braking stroke and the motor speed. In addition, parameters such as vehicle weight, tire friction coefficient, and motor output power may also affect the creep torque attenuation coefficient. Therefore, these factors need to be considered when calculating the creep torque attenuation coefficient. Finally, based on the creep torque attenuation coefficient, the final creep torque of the electric vehicle is determined for the corrected basic creep torque. This final creep torque is used to perform creep control on the electric vehicle. Through the braking system of the electric vehicle, this final creep torque is output to form the driving force for the electric vehicle to creep, enabling the electric vehicle to creep on a sloped road or a horizontal ground.

[0038] In the embodiments of the present invention, by calculating the slope of the road where the vehicle is located to compensate the basic creep torque of the electric vehicle, it is possible to ensure that the vehicle can maintain a stable creep speed when creeping uphill, improving the driving safety in the slope congestion following scenario. Secondly, by correcting the brake pedal stroke signal according to the slope, it is possible to avoid the situation of the vehicle rolling backward due to the influence of the slope after gently stepping on the vehicle and it stops on an uphill condition, further improving the driving safety. In addition, based on the slope-corrected brake pedal stroke signal, the creep torque is attenuated and corrected, which can reduce the overall vehicle energy consumption in the frequent brake releasing and stepping conditions during creep following. And the creep torque attenuation coefficient determined according to the slope-corrected braking stroke can also ensure that after the vehicle brakes and stops, the creep torque decays to zero, realizing a smooth gear shift and avoiding torque shock.

[0039] In some embodiments, to ensure that the electric vehicle can successfully activate the creep function, it is necessary to determine that the electric vehicle meets the creep function activation conditions. The creep function activation conditions include: the depth of the accelerator pedal is less than a preset depth limit value, and the motor speed is less than a preset speed limit value.

[0040] Since the prerequisite for the electric vehicle to creep must ensure that the driving speed of the vehicle is small enough, and the driving speed of the electric vehicle is generally determined according to the depth of the accelerator pedal of the electric vehicle and the speed of the motor. Therefore, in the embodiments of the present invention, the creep function activation conditions are formulated based on the depth of the accelerator pedal and the motor speed of the electric vehicle. The corresponding depth limit value is set for the depth of the accelerator pedal, and the corresponding speed limit value is set for the motor speed to control the driving speed of the electric vehicle.

[0041] When the depth of the accelerator pedal is less than the preset depth limit value and the motor speed is less than the preset speed limit value, it indicates that the current driving speed of the electric vehicle meets the creep function activation conditions. On the contrary, it indicates that the current driving speed does not meet the creep function activation conditions and cannot creep, and the creep control process ends.

[0042] In an embodiment of the present invention, by setting corresponding limits for the accelerator pedal depth and the motor speed, it is determined whether an electric vehicle meets the creep function activation condition, so as to ensure the successful activation of the creep function of the electric vehicle from a safety perspective and ensure driving safety.

[0043] In some embodiments, it is necessary to calculate the slope of the road where the electric vehicle is currently driving to correct the basic creep torque of the electric vehicle. The slope can be calculated from parameters such as the longitudinal acceleration and the vehicle speed increment of the electric vehicle. The following is a specific description.

[0044] First, within a preset time period determine the longitudinal acceleration and the vehicle speed increment of the electric vehicle. These can be obtained by installing vehicle sensors such as speedometers on the electric vehicle or the chassis system, and then calculate the slope of the current road through the following formula (1) : (1) where, represents the longitudinal acceleration, represents the vehicle speed increment, represents the preset time period, and g represents the acceleration due to gravity.

[0045] According to formula (1), the slope can be deduced as: (2) Of course, the time period here is preset. During the calculation process, N (N≥2) time periods can be preset as N cycles according to the actual scenario. A slope is calculated within each cycle, and then these slopes are subjected to average filtering processing. The result of the filtering processing can be determined as the final slope. In the average filtering processing, filtering processing methods such as simple moving average, weighted moving average, or exponentially weighted moving average can be selected. The basic principle of these methods is to perform weighted averaging on the data points within the window to reduce noise and sudden fluctuations and improve the accuracy of the results.

[0046] In an embodiment of the present invention, by presetting a time period as a cycle, within each cycle, by accurately obtaining parameters such as the longitudinal acceleration and the vehicle speed increment of the electric vehicle, the slope is calculated. Finally, the slope data of each cycle is subjected to average filtering processing, and the current road slope signal required for the creep function can be calculated more accurately.

[0047] In some embodiments, since the slope will affect the basic creep torque of the electric vehicle, it is necessary to calculate the corresponding compensation torque according to the slope and correct the basic creep torque of the electric vehicle Compensation is carried out to eliminate this influence. Therefore, here, the ramp compensation torque is first determined based on the slope and the motor speed. .

[0048] First, the influence of the slope on the vehicle resistance needs to be considered. When the vehicle is going uphill, due to the component force of gravity, the vehicle needs a greater driving force to overcome the gravity component. Therefore, this driving force can be calculated first, and then combined with the motor speed to calculate the total driving force required for the vehicle to go uphill. Combining with the wheel radius and the motor transmission efficiency, the corresponding required torque is calculated as the ramp compensation torque.

[0049] It should be noted that if the driving gear of the electric vehicle is the forward gear (D gear) and the slope is greater than 0 degrees, the ramp compensation torque is generally greater than 0 Nm. In other cases, the ramp compensation torque is generally equal to 0 Nm. At this time, it can be considered that the slope has no influence on the basic creep torque.

[0050] If the driving gear of the electric vehicle is the reverse gear (R gear) and the slope is less than 0 degrees, the ramp compensation torque is generally not less than 0 Nm. In other cases, the ramp compensation torque is equal to 0 Nm. At this time, it can be considered that the slope has no influence on the basic creep torque.

[0051] Generally, under normal circumstances, the sum of the ramp compensation torque and the basic creep torque is used as the corrected basic creep torque, denoted as .

[0052] In the embodiments of the present invention, by determining the current road slope signal and then performing ramp compensation on the creep torque based on the slope, it is possible to ensure that the vehicle can still maintain a stable creep vehicle speed when creeping uphill, improving the driving safety in the vehicle-following condition during slope congestion.

[0053] In some embodiments, in order to reduce the overall vehicle energy consumption in the frequent brake release and depression conditions during creep vehicle-following, it is necessary to correct the brake pedal stroke according to the slope to obtain the slope-corrected brake stroke, so as to calculate the corresponding creep torque attenuation coefficient and further correct the corrected basic creep torque.

[0054] When correcting the brake pedal stroke according to the slope, it needs to be determined according to different situations, because the slope will also affect the brake pedal stroke. First, it is necessary to judge whether the specific situation of the slope is 0. When the slope is not 0 degrees, it means that the electric vehicle is going uphill or downhill normally. At this time, the brake pedal stroke of the electric vehicle is obtained , which can be monitored and read by sensor devices such as a travel meter installed on the electric vehicle or the chassis system. Then, the brake stroke correction amount based on the slope is determined according to the slope. 。

[0055] Finally, the difference between the brake pedal stroke and the brake stroke correction amount is used as the slope correction brake stroke L, that is 。 。

[0056] When the slope is 0 degrees, it means that the electric vehicle is driving normally on a horizontal ground. At this time, there is no error in the braking distance of the electric vehicle, so the brake pedal stroke is directly used as the slope correction brake stroke L, that is 。

[0057] In the embodiment of the present invention, by correcting the brake pedal stroke signal of the electric vehicle according to the slope, it is possible to avoid the situation of the vehicle slipping backward due to the influence of the slope after gently stepping on the vehicle to stop in the uphill working condition, thereby improving the driving safety.

[0058] In some embodiments, the slope correction brake stroke under the influence of the slope is calculated, and then based on the slope correction brake stroke, the creep torque attenuation system and the corrected basic creep torque are determined to obtain the final creep torque of the electric vehicle. Because during the uphill creep process, the required creep torque changes dynamically with the brake stroke, and there is a certain attenuation relationship between the two, it is necessary to determine the creep torque attenuation coefficient according to the corrected brake stroke to further correct the basic creep torque after slope correction. Among them, the creep torque attenuation coefficient used to characterize this attenuation relationship is determined based on the slope correction brake stroke and the motor speed.

[0059] Specifically, first, the creep torque attenuation coefficient is determined according to the slope correction brake stroke. The creep torque attenuation coefficient is mainly related to the brake stroke and the motor speed. In addition, vehicle weight, tire friction coefficient, motor output power, etc. These parameters may also affect the creep torque attenuation coefficient. An empirical formula of the creep torque attenuation coefficient can be fitted through these parameters. After calculating the slope correction brake stroke L, the motor speed and other parameters are then substituted into the empirical formula to calculate the creep torque attenuation coefficient 。

[0060] Finally, through the creep torque attenuation coefficient , the corrected basic creep torque is corrected to obtain the final creep torque T of the electric vehicle, expressed as: (3) After determining the final creep torque of the electric vehicle, the braking system of the electric vehicle outputs this final creep torque to form the driving force for the electric vehicle to creep, enabling the electric vehicle to creep on a sloped road.

[0061] In the embodiment of the present invention, based on the brake pedal stroke signal after slope correction, the creep torque of the electric vehicle after slope correction is attenuated and corrected, which can reduce the overall vehicle energy consumption under the condition of frequently releasing and stepping on the brake during creep following, and at the same time, it can also ensure that after the vehicle brakes to a standstill, the creep torque decays to zero, realizing a smooth gear shift and avoiding torque impact.

[0062] The embodiment of the present invention also provides an electric vehicle creep control system, as Figure 2 shown. This system includes the following modules: a gear and motor speed control module 201, a creep basic control torque calculation module 202, a creep torque compensation module 203 based on slope, a brake pedal stroke correction module 204 based on slope, and a final creep control torque calculation module 205.

[0063] Specifically, the gear and motor speed control module 201 is used to detect the depth of the accelerator pedal and the motor speed when the driving gear of the electric vehicle is in the forward gear or reverse gear; the creep basic control torque calculation module 202 is used to determine the basic creep torque of the electric vehicle according to the motor speed and the motor ambient temperature when the depth of the accelerator pedal and the motor speed meet the creep function activation conditions; the creep torque compensation module 203 based on slope is used to determine the slope of the current road and compensate the basic creep torque based on the slope and the motor speed to obtain the corrected basic creep torque; the brake pedal stroke correction module 204 based on slope is used to correct the brake pedal stroke according to the slope to obtain the slope-corrected brake stroke; the final creep control torque calculation module 205 is used to determine the final creep torque of the electric vehicle based on the creep torque attenuation system determined by the slope-corrected brake stroke and the corrected basic creep torque, and the final creep torque is used to control the creep of the electric vehicle.

[0064] It should be noted that the beneficial effects of the electric vehicle creep control system here correspond to those of the electric vehicle creep control method in the above text, so the beneficial effects of the electric vehicle creep control system are not elaborated here.

[0065] Figure 3 Illustrates a schematic physical structure diagram of an electronic device, as Figure 3As shown in the figure, the electronic device may include: a processor 310, a communications interface 320, a memory 330, and a communication bus 340. Among them, the processor 310, the communications interface 320, and the memory 330 complete communication with each other through the communication bus 340. The processor 310 may call the logic instructions in the memory 330 to execute the electric vehicle creep control method, which includes: when the driving gear of the electric vehicle is in the forward gear or reverse gear, detecting the depth of the accelerator pedal and the motor speed; when the depth of the accelerator pedal and the motor speed meet the creep function activation condition, determining the basic creep torque of the electric vehicle according to the motor speed and the motor ambient temperature; determining the slope of the current road, and compensating the basic creep torque based on the slope and the motor speed to obtain a corrected basic creep torque; correcting the brake pedal stroke according to the slope to obtain a slope-corrected brake stroke; determining the final creep torque of the electric vehicle based on the creep torque attenuation system determined by the slope-corrected brake stroke and the corrected basic creep torque, and the final creep torque is used to perform creep control on the electric vehicle.

[0066] In addition, when the logic instructions in the above-mentioned memory 330 can be implemented in the form of software functional units and sold or used as an independent product, they can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs that can store program codes.

[0067] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the electric vehicle creep control method provided by each of the above methods. The method includes: when the driving gear of the electric vehicle is in the forward gear or the reverse gear, detecting the depth of the accelerator pedal and the motor speed; when the depth of the accelerator pedal and the motor speed meet the creep function activation condition, determining the basic creep torque of the electric vehicle according to the motor speed and the motor ambient temperature; determining the slope of the current road, and compensating the basic creep torque based on the slope and the motor speed to obtain a corrected basic creep torque; correcting the brake pedal stroke according to the slope to obtain a slope-corrected brake stroke; determining the final creep torque of the electric vehicle based on the creep torque attenuation system determined by the slope-corrected brake stroke and the corrected basic creep torque, and the final creep torque is used to control the creep of the electric vehicle.

[0068] In another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it is implemented to execute the electric vehicle creep control method provided by each of the above methods. The method includes: when the driving gear of the electric vehicle is in the forward gear or the reverse gear, detecting the depth of the accelerator pedal and the motor speed; when the depth of the accelerator pedal and the motor speed meet the creep function activation condition, determining the basic creep torque of the electric vehicle according to the motor speed and the motor ambient temperature; determining the slope of the current road, and compensating the basic creep torque based on the slope and the motor speed to obtain a corrected basic creep torque; correcting the brake pedal stroke according to the slope to obtain a slope-corrected brake stroke; determining the final creep torque of the electric vehicle based on the creep torque attenuation system determined by the slope-corrected brake stroke and the corrected basic creep torque, and the final creep torque is used to control the creep of the electric vehicle.

[0069] The device embodiments described above are merely illustrative. The units described 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 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. Those of ordinary skill in the art can understand and implement it without creative labor.

[0070] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on such an understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A creep control method for an electric vehicle, characterized in that: The method comprises: When the electric vehicle is in the forward gear or reverse gear, the accelerator pedal depth and the motor speed are detected; When the accelerator pedal depth and the motor speed meet the creep function activation condition, determining the basic creep torque of the electric vehicle according to the motor speed and the motor ambient temperature; Determining the slope of the current road, and compensating the basic creep torque based on the slope and the motor speed to obtain a corrected basic creep torque; Correcting the brake pedal stroke according to the slope to obtain a slope-corrected braking stroke; Based on the creep torque attenuation coefficient determined by the slope correction braking stroke and the corrected basic creep torque, a final creep torque of the electric vehicle is determined, and the final creep torque is used to perform creep control on the electric vehicle.

2. The electric vehicle creep control method according to claim 1, characterized in that: The creeping function activation conditions include: The accelerator pedal depth is less than a preset depth limit, and the motor speed is less than a preset speed limit.

3. The electric vehicle creep control method according to claim 1, characterized in that: Determining the slope of the current road includes: Determining the longitudinal acceleration and the speed increment of the electric vehicle within a preset time period; The slope of the current road is calculated according to the following formula: in, represents the longitudinal acceleration, represents the vehicle speed increment, represents the preset time period, and g represents the gravitational acceleration.

4. The electric vehicle creep control method according to claim 1, characterized in that: The compensating the basic creep torque based on the slope and the motor speed to obtain a corrected basic creep torque includes: Determining a slope compensation torque based on the slope and the motor speed; The sum of the ramp compensation torque and the basic creep torque is used as the corrected basic creep torque.

5. The electric vehicle creep control method according to claim 1, characterized in that: The step of correcting the brake pedal stroke according to the slope to obtain a slope-corrected braking stroke includes: When the slope is not 0 degrees, determining a slope-based brake stroke correction amount according to the slope; Using the difference between the brake pedal stroke and the brake stroke correction amount as the slope correction brake stroke; When the slope is 0 degrees, the brake pedal stroke is used as the slope-corrected braking stroke.

6. The electric vehicle creep control method according to claim 1, characterized in that: Said The method comprises: determining a final creep torque of the electric vehicle based on a creep torque attenuation system determined by the slope correction braking stroke and the corrected basic creep torque, comprising: The corrected basic creep torque is corrected by the creep torque attenuation coefficient to obtain the final creep torque of the electric vehicle; The creep torque attenuation coefficient is determined based on the slope-corrected braking stroke and the motor speed.

7. An electric vehicle creep control system, characterized in that: The system comprises: The gear position and motor speed control module is used to detect the accelerator pedal depth and motor speed when the electric vehicle is in the forward gear or reverse gear; A creep basic control torque calculation module, used to determine the basic creep torque of the electric vehicle according to the motor speed and the motor ambient temperature when the accelerator pedal depth and the motor speed meet the creep function activation condition; A creep torque compensation module based on a slope, used to determine the slope of a current road, and to compensate the basic creep torque based on the slope and the motor speed to obtain a corrected basic creep torque; A brake pedal stroke correction module based on the slope, used to correct the brake pedal stroke according to the slope to obtain a slope-corrected brake stroke; The final creep control torque calculation module is used to determine the final creep torque of the electric vehicle based on the creep torque attenuation coefficient determined by the slope correction braking stroke and the corrected basic creep torque, and the final creep torque is used to perform creep control on the electric vehicle.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the electric vehicle creep control method according to any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the electric vehicle creep control method according to any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the electric vehicle creep control method according to any one of claims 1 to 6 is implemented.

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