Vehicle hill-holding control method, device, new energy vehicle and storage medium

Abstract

The present application relates to a vehicle holding hill control method, device, new energy vehicle and storage medium. The method includes: when the vehicle's motor holding hill function is activated, determining the initial value of the holding hill torque and the dynamic value of the holding hill torque corresponding to the vehicle motor; determining the holding hill torque correction value based on the initial value of the holding hill torque and the dynamic value of the holding hill torque; obtaining the clamping torque recorded for the vehicle during the holding hill process, and determining the holding hill torque target value based on the clamping torque and the holding hill torque correction value; controlling the vehicle motor based on the holding hill torque target value to make the vehicle hold the hill. The use of this method can achieve more accurate vehicle holding hills, avoid holding hill failures due to excessive or too small holding hill torque target values, and thus ensure driving safety.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a vehicle hill-holding control method, device, new energy vehicle, computer-readable storage medium, and computer program product. Background Art

[0002] Vehicles usually hold the vehicle on a hill using the clamping torque of the brakes. With the development of new energy vehicle technology, a method of using the vehicle's motor to hold the vehicle on a hill has emerged, but the corresponding accuracy needs to be improved, and the vehicle may slip. Summary of the invention

[0003] Based on this, it is necessary to provide a vehicle holding hill control method, device, new energy vehicle, computer readable storage medium and computer program product to address the above technical problems, so as to improve the accuracy of using the vehicle motor to hold the hill and ensure driving safety.

[0004] In a first aspect, the present application provides a vehicle hill-holding control method, comprising:

[0005] When the motor holding-hill function of the vehicle is activated, determining an initial holding-hill torque value and a dynamic holding-hill torque value corresponding to the motor of the vehicle;

[0006] Determining a hill-holding torque correction value based on the hill-holding torque initial value and the hill-holding torque dynamic value;

[0007] Obtaining the clamping torque recorded for the vehicle during the hill-holding process, and determining a hill-holding torque target value based on the clamping torque and the hill-holding torque correction value;

[0008] The vehicle motor is controlled based on the hill-holding torque target value to keep the vehicle on the hill.

[0009] In one of the embodiments, a hill-holding torque correction value is determined based on an initial hill-holding torque value and a dynamic hill-holding torque value, including: determining a first confidence level of the dynamic hill-holding torque value based on a degree of fluctuation of the dynamic hill-holding torque value within a preset period; determining a second confidence level corresponding to the initial hill-holding torque value according to the first confidence level; the sum of the first confidence level and the second confidence level is 1; and merging the initial hill-holding torque value and the dynamic hill-holding torque value according to the first confidence level and the second confidence level to obtain a hill-holding torque correction value.

[0010] In one embodiment, determining a first confidence level of the dynamic value of the hill-holding torque based on the degree of fluctuation of the dynamic value of the hill-holding torque within a preset period includes:

[0011] Determine an initial confidence level of the dynamic value of the hill-holding torque; the initial confidence level is determined based on a difference between an actual variance value corresponding to a plurality of dynamic values ​​of the hill-holding torque within a preset period and a preset target variance value;

[0012] Obtaining the speed change rate of the vehicle under the control of the dynamic value of the hill-holding torque with an initial confidence level;

[0013] Based on the vehicle speed change rate, the initial confidence is corrected to obtain the first confidence of the dynamic value of the hill-holding torque; wherein, when the vehicle speed change rate increases, the initial confidence is reduced; when the vehicle speed change rate decreases, the initial confidence is increased.

[0014] In one of the embodiments, based on the clamping torque and the hill-holding torque correction value, a target hill-holding torque required by a vehicle motor is determined, including: obtaining a slope value range corresponding to the hill-holding torque correction value, and obtaining a clamping torque corresponding to the same slope value range; obtaining a first variance of the hill-holding torque correction value and a second variance of the clamping torque; determining weights corresponding to the hill-holding torque correction value and the clamping torque respectively according to the first variance and the second variance; based on the weights, fusing the hill-holding torque correction value and the clamping torque to obtain the target hill-holding torque.

[0015] In one embodiment, the weights corresponding to the hill-holding torque correction value and the clamping torque are determined according to the first variance and the second variance, including: determining the sum of the first variance and the second variance as the total variance; determining the proportion of the first variance to the total variance as the first proportion, and the proportion of the second variance to the total variance as the second proportion; determining the weights corresponding to the hill-holding torque correction value and the clamping torque according to the first proportion and the second proportion; wherein the weight corresponding to the hill-holding torque correction value is negatively correlated with the first proportion, and the weight corresponding to the clamping torque is negatively correlated with the second proportion.

[0016] In one embodiment, determining the dynamic value of the hill-holding torque required by the vehicle's motor includes: obtaining the vehicle's speed change rate and the corresponding driving force when preset vehicle mass estimation conditions are met; determining the vehicle's mass based on a linear regression analysis of the vehicle's speed change rate and the corresponding driving force; determining the slope of the road on which the vehicle is located; and determining the dynamic value of the hill-holding torque based on the vehicle's mass and the road slope.

[0017] In one of the embodiments, the vehicle hill-holding control method also includes: acquiring driving status information of the vehicle; determining that a preset vehicle mass estimation condition is met when the driving status information satisfies the following conditions: the vehicle speed change rate is greater than a preset estimated vehicle speed change rate threshold; the vehicle's lateral acceleration is less than a preset estimated lateral acceleration threshold; the vehicle's steering wheel angle is less than a preset estimated steering wheel angle threshold; and the vehicle is in a non-slip state.

[0018] In one of the embodiments, the vehicle's mass is determined based on a linear regression analysis of the vehicle speed change rate and the corresponding driving force, including: determining the vehicle's current estimated vehicle mass based on a linear regression analysis of the vehicle speed change rate and the corresponding driving force; determining the degree of fluctuation of multiple estimated vehicle masses within a set period; when the degree of fluctuation is less than or equal to a preset threshold, determining the current estimated vehicle mass as the vehicle's mass; when the degree of fluctuation is greater than a preset threshold, determining the preset vehicle mass as the vehicle's mass.

[0019] In one embodiment, determining an initial value of the hill-holding torque corresponding to a motor of a vehicle includes: when the vehicle speed is within a preset hill-holding speed range, determining the slope of a road on which the vehicle is located, and determining an initial value of the hill-holding torque corresponding to the slope of the road based on a preset slope-torque correspondence table.

[0020] In a second aspect, the present application also provides a vehicle hill-holding control device, comprising:

[0021] A first determination module is used to determine an initial value of the hill-holding torque and a dynamic value of the hill-holding torque corresponding to the motor of the vehicle when the hill-holding function of the motor of the vehicle is activated;

[0022] A second determination module is used to determine a hill-holding torque correction value based on the hill-holding torque initial value and the hill-holding torque dynamic value;

[0023] A third determination module is used to obtain the clamping torque recorded for the vehicle during the hill-holding process, and determine the hill-holding torque target value based on the clamping torque and the hill-holding torque correction value;

[0024] The hill-holding control module is used to control the vehicle motor based on the hill-holding torque target value to make the vehicle stay on the hill.

[0025] In a third aspect, the present application further provides a new energy vehicle, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the vehicle hill-holding control method in the aforementioned first aspect when executing the computer program.

[0026] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the vehicle hill-holding control method in the aforementioned first aspect are implemented.

[0027] In a fifth aspect, the present application further provides a computer program product, comprising a computer program, which, when executed by a processor, implements the steps of the vehicle hill-holding control method in the aforementioned first aspect.

[0028] The above-mentioned vehicle holding hill control method, device, new energy vehicle, computer-readable storage medium and computer program product, by determining the initial value and dynamic value of the holding hill torque corresponding to the vehicle motor when the holding hill function of the vehicle motor is activated, and comprehensively determining the holding hill torque correction value according to the initial value and dynamic value of the holding hill torque, which can make timely response when the vehicle needs to hold the hill, and obtain a more accurate holding hill torque correction value. At the same time, the holding hill torque target value is comprehensively determined according to the clamping torque and the holding hill torque correction value of the vehicle's recorded holding hill process, so that the obtained holding hill torque target value is more matched with the current vehicle situation, so that the vehicle motor is controlled according to the holding hill torque target value, which can achieve more accurate holding hill of the current vehicle and avoid holding hill failure due to excessive or too small holding hill torque target value. At the same time, it can achieve holding hill of the vehicle in the case of vehicle brake failure, thereby ensuring driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A schematic diagram of a first flow chart of a vehicle hill-holding control method in one embodiment;

[0031] Figure 2 A second flow chart of a vehicle holding hill control method in one embodiment;

[0032] Figure 3 A third flow chart of a vehicle hill-holding control method in one embodiment;

[0033] Figure 4 A fourth flow chart of a vehicle hill-holding control method in one embodiment;

[0034] Figure 5 is a structural block diagram of a vehicle hill-holding control device in one embodiment;

[0035] Figure 6 Schematic diagram of the internal structure of a new energy vehicle in one embodiment. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is 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.

[0037] Before describing the technical solution of this application in detail, the terms / nouns involved are explained as follows:

[0038] Traditional braking systems, including traditional brake systems, mainly control the deceleration and stopping process of the vehicle by adjusting the clamping torque.

[0039] The motor and motor controller, where the motor is the core component that converts electrical energy into mechanical energy and provides power when the vehicle is driving. The motor controller is responsible for controlling the motor's speed and torque output. It receives instructions from the vehicle control system and adjusts the motor's working state so that the motor can achieve the functions of acceleration, deceleration and braking. Specifically, the motor controller can change the motor's working state by adjusting the current and voltage, and decide whether the motor drives the vehicle forward or recovers energy.

[0040] Stalled rotor is a situation where the motor still outputs torque when the speed is 0 rpm.

[0041] D gear (Drive gear) is the vehicle's forward gear. Normally, the motor should rotate forward at this time and the motor speed should be a positive value. If the motor rotates backward at this time, it indicates that the motor is reversed.

[0042] R gear (Reverse gear) is the reverse gear of the vehicle. Under normal circumstances, the motor should rotate backward at this time and the motor speed should be a negative value; if the motor rotates forward at this time, it indicates that the motor is reversed.

[0043] Among them, the motor and the motor controller can also constitute an electric braking system. The electric braking system can be understood as adjusting the reverse torque of the motor through the motor controller to achieve vehicle deceleration or parking. In this process, the vehicle is braked by converting electrical energy into mechanical energy. The principles involved include energy recovery and braking control. Energy recovery can be understood as when the vehicle decelerates or stops, the motor controller controls the motor to generate reverse torque, converts the vehicle's kinetic energy into electrical energy, and stores it back in the battery, thereby extending the cruising range. This control method can reduce dependence on traditional mechanical brakes. Correspondingly, the electric braking process can be understood as the process of controlling vehicle braking mainly through the electric braking system.

[0044] As mentioned above, for vehicles equipped with motors, they can hold the vehicle on a slope by using the motors, but there are technical problems such as poor accuracy in holding the vehicle on a slope by using the motors. At the same time, from the perspective of vehicle driving safety, if there is a problem with the vehicle's brakes, such as failure, then holding the vehicle on a slope by using the motors provides another braking capability to achieve emergency braking and keep the vehicle on the slope as much as possible. Therefore, how to use the motors to hold the vehicle on a slope to ensure driving safety in the event of brake failure is another interpretation of the aforementioned technical problem.

[0045] To solve the above problems, the present application proposes that, when the motor hill-holding function of the vehicle is activated, the dynamic value of the hill-holding torque required to control the vehicle's deceleration and the initial value of the hill-holding torque required to stop at a hill can be determined, and the initial value of the hill-holding torque and the dynamic value of the hill-holding torque are comprehensively considered to re-determine a hill-holding torque correction value, and then the clamping torque recorded during the hill-holding process of the vehicle is comprehensively considered to determine the hill-holding torque target value, and the motor is controlled based on the hill-holding torque target value, which can improve the accuracy of the vehicle when stopping at a hill based on the motor.

[0046] In one embodiment, Figure 1 As shown, a vehicle holding hill control method is provided. This embodiment takes the method applied to a new energy vehicle as an example. It can be understood that the method can also be applied to other types of vehicles, as long as the vehicle is equipped with a motor and a motor controller, the motor and the motor controller can provide driving force for the vehicle.

[0047] In this embodiment, the method includes steps S101 to S104:

[0048] Step S101: when the hill-holding function of the motor of the vehicle is activated, determining the initial value of the hill-holding torque and the dynamic value of the hill-holding torque corresponding to the motor of the vehicle.

[0049] Among them, the motor or vehicle motor can be a motor that provides driving force when the vehicle is driving normally, that is, a driving motor. When it is necessary to hold the vehicle on a hill, the motor is locked to provide the torque required for holding the hill. Of course, it can also be other motors in the vehicle, as long as the motor can provide the torque required for the vehicle to hold the hill by locking the motor.

[0050] Among them, the motor holding hill function can be a function for controlling the motor in the vehicle to hold the hill. In some cases, it is also called a motor braking function or an electric braking function. Exemplarily, the activation of the motor holding hill function can be like other functions in the vehicle, such as reversing images, which can be automatically activated when the preset conditions are met, and of course, it can also be automatically turned off when the preset conditions are met. Exemplarily, the preset conditions may include automatic activation conditions, for example, the driver's voice commands can be captured, and when the voice commands indicate that the hill holding function needs to be held, the motor holding hill function can be automatically activated; of course, specific function buttons, keys, etc. can also be set, just like the vehicle's turn signal lever, emergency light button, etc., when it is pressed by the driver, it indicates that the hill holding function needs to be held, and the motor holding hill function can be automatically activated.

[0051] The initial value of the holding torque may be the initial torque required by the vehicle motor to hold the vehicle on a hill, and the dynamic value of the holding torque may be the dynamic torque required by the vehicle motor to hold the vehicle on a hill.

[0052] Exemplarily, the initial value of the hill-holding torque corresponding to the motor of the vehicle can be determined by looking up a table. For example, a relationship table corresponding to the slope of the vehicle and the initial value of the hill-holding torque. Exemplarily, the table here can be preset, for example, obtained by preliminary experimental statistics. At the same time, the dynamic value of the hill-holding torque required for the vehicle to stay on the hill can be calculated by vehicle dynamics. In this way, the initial value of the hill-holding torque and the dynamic value of the hill-holding torque can be determined more quickly, and at the same time, the determined initial value of the hill-holding torque and the dynamic value of the hill-holding torque are more accurate.

[0053] Step S102: determining a hill-holding torque correction value based on the hill-holding torque initial value and the hill-holding torque dynamic value.

[0054] Among them, the initial value of the hill-holding torque and the dynamic value of the hill-holding torque can be used to characterize the torque required for hill-holding control by the vehicle motor from two different stages. The torque value of a single stage may have poor accuracy due to factors such as one-sidedness. Therefore, the two can be combined to obtain the hill-holding torque correction value.

[0055] In some embodiments, the hill-holding torque correction value may be understood as a torque value obtained by correcting the hill-holding torque initial value through the hill-holding torque dynamics.

[0056] In some embodiments, the dynamic value of the hill-holding torque can be dynamically changed. As the actual hill-holding progress of the vehicle is different, different dynamic values ​​of the hill-holding torque may correspond, so that the initial value of the hill-holding torque can be corrected multiple times, that is, different hill-holding torque correction values ​​can be obtained, so that the hill-holding torque correction value can be synchronized with the actual hill-holding progress of the vehicle, and the latest determined hill-holding torque correction value can be used in subsequent calculations to ensure the accuracy of the hill-holding torque target value.

[0057] Step S103: obtaining the clamping torque recorded for the vehicle during the hill-holding process, and determining the hill-holding torque target value based on the clamping torque and the hill-holding torque correction value.

[0058] The clamping torque may be a torque corresponding to the vehicle holding a hill by a conventional braking system, for example, the clamping torque of a brake caliper of a car.

[0059] For example, for a vehicle to hold a hill, it is sufficient to slow down and stabilize the vehicle on the slope. As mentioned above, holding a hill can also be achieved through the vehicle's braking system. Therefore, in the process of holding a hill using a motor, you can refer to the relevant content of holding a hill using brakes to improve the accuracy of holding a hill using a motor.

[0060] Exemplarily, as described above, since the vehicle hill-holding control method provided in the present application can cope with hill-holding when the vehicle brakes fail, the reference to hill-holding by braking here can be a reference to hill-holding by braking that occurred in a past time period when the vehicle brakes had not failed.

[0061] For example, the clamping torque recorded by the vehicle during the hill-holding process may be the relevant torque data automatically recorded by the vehicle in the past time period when the vehicle brakes have not failed, which is achieved by braking to hold the hill, or it may be obtained and recorded by the vehicle through the cloud, factory pre-settings, vehicle system updates, etc.

[0062] In some embodiments, after comprehensively considering the initial value of the hill-holding torque and the dynamic value of the hill-holding torque to determine a hill-holding torque correction value, the clamping torque and the hill-holding torque correction value can also be comprehensively considered to obtain a more accurate torque value - the hill-holding torque target value.

[0063] Step S104: Controlling the vehicle motor based on the hill-holding torque target value to make the vehicle hold the hill.

[0064] In this embodiment, when the vehicle's motor holding function is activated, the initial value of the holding torque and the dynamic value of the holding torque corresponding to the vehicle motor are determined, and the holding torque correction value is comprehensively determined based on the initial value of the holding torque and the dynamic value of the holding torque, which can make timely responses when the vehicle needs to hold the hill and obtain a more accurate holding torque correction value. At the same time, the holding torque target value is comprehensively determined based on the clamping torque and the holding torque correction value of the vehicle's recorded holding process, which makes the obtained holding torque target value more compatible with the current vehicle's situation. Therefore, the vehicle motor is controlled according to the holding torque target value, which can achieve more accurate holding of the current vehicle and avoid holding failure due to excessive or too small holding torque target value. At the same time, it can achieve holding the vehicle on the hill when the vehicle brake fails, thereby ensuring driving safety.

[0065] In one embodiment, if Figure 2 As shown, the “determining the hill-holding torque correction value based on the hill-holding torque initial value and the hill-holding torque dynamic value” in the above embodiment may include steps S201 to S203:

[0066] Step S201: determining a first confidence level of the dynamic value of the hill-holding torque based on the degree of fluctuation of the dynamic value of the hill-holding torque within a preset period.

[0067] The degree of fluctuation may be a representation of the difference in dynamic values ​​of the hill-holding torque at different times. If the difference is large, the degree of fluctuation is large.

[0068] Step S202: Determine a second confidence level corresponding to the initial value of the hill-holding torque according to the first confidence level; the sum of the first confidence level and the second confidence level is 1.

[0069] Step S203: According to the first confidence level and the second confidence level, the initial value of the hill-holding torque and the dynamic value of the hill-holding torque are merged to obtain a hill-holding torque correction value.

[0070] For example, the dynamic value of the holding torque on a hill may be estimated, dynamic, and subject to fluctuations, and thus may be corrected. For example, different weights may be given according to the different degrees of stability of the dynamic value of the holding torque on a hill.

[0071] For example, the first confidence level of the dynamic value of the holding torque can be determined by the degree of fluctuation of the dynamic value of the holding torque within a preset period, such as the variance. For example, if the variance is small, the first confidence level can be high, such as 80%. Accordingly, the initial value of the holding torque can also have a corresponding confidence level, namely, the second confidence level, which can be equal to 1 minus the first confidence level.

[0072] In this embodiment, considering the volatility of the dynamic value of the hill-holding torque, the corresponding accuracy may be poor. Therefore, the confidence level is used for adjustment. Specifically, the first confidence level is determined according to the degree of fluctuation of the dynamic value of the hill-holding torque within a preset period, so as to derive the second confidence level corresponding to the initial value of the hill-holding torque. The initial value of the hill-holding torque and the dynamic value of the hill-holding torque are merged according to the first confidence level and the second confidence level, so as to obtain a more accurate hill-holding torque correction value.

[0073] In one of the embodiments, the "determining a first confidence level of the dynamic value of the hill-holding torque based on the degree of fluctuation of the dynamic value of the hill-holding torque within a preset period" in the aforementioned embodiment may include: determining an initial confidence level of the dynamic value of the hill-holding torque; determining the initial confidence level based on the difference between actual variance values ​​corresponding to multiple dynamic values ​​of the hill-holding torque within a preset period and a preset target variance value; obtaining the speed change rate of the vehicle under the control of the dynamic value of the hill-holding torque with the initial confidence level; correcting the initial confidence level based on the speed change rate to obtain a first confidence level of the dynamic value of the hill-holding torque; wherein, when the speed change rate increases, the initial confidence level is reduced; and when the speed change rate decreases, the initial confidence level is increased.

[0074] Exemplarily, regarding the confidence of the dynamic value of the hill-holding torque, an initial value, namely the initial confidence, can be determined first, and the vehicle can be held on the hill based on the initial confidence. At the same time, the corresponding hill-holding effect can be observed. If the hill-holding effect is good, it means that the corresponding hill-holding torque dynamic value has good credibility, and the initial confidence can be improved; otherwise, the initial confidence can be reduced.

[0075] For example, the corresponding hill-holding effect can be observed by the vehicle speed change rate. If the speed change rate decreases, it means that the initial confidence has a positive effect on the vehicle hill-holding, and the initial confidence can be increased. On the contrary, if the speed change rate increases, it means that the initial confidence has a negative effect on the vehicle hill-holding, and the initial confidence can be reduced.

[0076] In this embodiment, regarding the confidence level of the dynamic value of the hill-holding torque, an initial confidence level is first determined, and then the initial confidence level is adjusted based on the vehicle speed change rate corresponding to the initial confidence level. A feedback adjustment mechanism between the vehicle speed change rate and the confidence level of the dynamic value of the hill-holding torque is established, so that the first confidence level of the dynamic value of the hill-holding torque can be adjusted in time according to changes in the actual hill-holding state of the vehicle, thereby obtaining a more accurate first confidence level.

[0077] In one of the embodiments, the "determining the target hill-holding torque value required by the vehicle motor based on the clamping torque and the hill-holding torque correction value" in the aforementioned embodiment may include: obtaining the slope value range corresponding to the hill-holding torque correction value, and obtaining the clamping torque corresponding to the same slope value range; obtaining the first variance of the hill-holding torque correction values ​​obtained multiple times and the second variance of multiple clamping torques; determining the weights corresponding to the hill-holding torque correction value and the clamping torque respectively according to the first variance and the second variance; based on the weight, fusing the currently obtained hill-holding torque correction value with the clamping torque to obtain the target hill-holding torque value.

[0078] The slope value range may be a numerical range of the slope of the road on which the vehicle is located. The range here may be understood in a broad sense, and may be either a specific slope value, such as 10 degrees, or a slope range, such as 10 degrees to 12 degrees.

[0079] For example, the slope value range corresponding to the clamping torque and the slope value range corresponding to the slope holding torque correction value may be the same, and the same here can be understood in a broad sense, and can be completely the same or partially the same. For example, the slope value range corresponding to the clamping torque is 11 degrees to 12 degrees, and the slope value range corresponding to the slope holding torque correction value is 10 degrees to 12 degrees, which can be considered to be the same.

[0080] For example, the slope value range corresponding to the clamping torque and the slope value range corresponding to the slope holding torque correction value can adopt the same slope range division standard. For example, with 0 degrees as the origin and every 2 degrees as a slope range, the corresponding slope range can be [0, +2), [+2, +4), [+4, +6), etc., and [-2, 0), [-4, -2), [-6, -4), etc. By adopting the same slope range division standard, the clamping torque and the slope holding torque correction value with the same slope value range can be obtained.

[0081] For example, the determination of the target value of the hill-holding torque required by the vehicle motor can refer to the clamping torque. The road slope corresponding to the clamping torque referred to here can be the same as the actual road slope of the vehicle, or the difference between the two can be small, so as to obtain a more accurate reference. For example, a threshold can be set to measure whether it is "small difference". For example, the threshold can be set to 2 degrees. The road slope corresponding to the clamping torque is 10 degrees, and the actual road slope of the vehicle is 11 degrees. The difference is only 1 degree, which means that the difference is small.

[0082] For example, the clamping torque and the hill-holding torque correction value may be weighted to achieve integration of the two, thereby obtaining the hill-holding torque target value. The weights here may be determined based on their corresponding variances.

[0083] In some possible embodiments, during the vehicle holding a hill, since the dynamic value of the holding torque may be dynamic, a plurality of holding torque correction values ​​may be calculated multiple times during the holding hill process, and thus a corresponding first variance may be determined for the plurality of holding torque correction values.

[0084] In some possible embodiments, the clamping torques and their corresponding slopes during the vehicle's previous multiple hill-holding processes may be recorded, from which multiple clamping torques within the same slope range as the slope of the current hill-holding road surface are screened out, and the corresponding variances are determined as the second variance of the clamping torque above.

[0085] In this embodiment, since the vehicle holding effect achieved by the clamping torque is usually better when the vehicle braking system is normal, the holding torque target value obtained by fusing the clamping torque with the holding torque correction value is more accurate and can achieve more accurate holding. At the same time, the holding torque correction value is the same as the slope value range corresponding to the clamping torque, which helps to ensure that the actual holding conditions corresponding to the clamping torque and the holding torque correction value are the same, so that the two can be matched and merged. In addition, the weights of the clamping torque and the holding torque correction value are determined by the variance, and the two are merged based on the weights, which can obtain a more accurate holding torque target value.

[0086] In one of the embodiments, the "determining the weights corresponding to the hill-holding torque correction value and the clamping torque respectively according to the first variance and the second variance" in the aforementioned embodiment may include: determining the sum of the first variance and the second variance as the total variance; determining the proportion of the first variance to the total variance as the first proportion, and the proportion of the second variance to the total variance as the second proportion, and determining the weights corresponding to the hill-holding torque correction value and the clamping torque respectively according to the first proportion and the second proportion; wherein the weight corresponding to the hill-holding torque correction value is negatively correlated with the first proportion, and the weight corresponding to the clamping torque is negatively correlated with the second proportion.

[0087] Exemplarily, since the first variance can reflect the fluctuation degree of the hill-holding torque correction value, the second variance can reflect the fluctuation degree of the clamping torque. If the fluctuation degree is greater, it means that the data is more unstable, and thus the corresponding weight can be reduced; otherwise, the corresponding weight can be increased.

[0088] For example, the sum of the first proportion and the second proportion is 1; the weight corresponding to the slope-holding torque correction value is determined according to the difference between 1 and the first proportion; the weight corresponding to the clamping torque is determined according to the difference between 1 and the second proportion. For example, if the first variance is A1 and the second variance is B1, then the first proportion is A1 / (A1+B1), the second proportion is B1 / (A1+B1), and the sum of A1 / (A1+B1) and B1 / (A1+B1) is equal to 1.

[0089] Exemplarily, the difference between 1 and the first proportion can be used as the weight corresponding to the hill-holding torque correction value, thereby achieving the following: when the first variance increases, the first proportion increases, and the weight corresponding to the hill-holding torque correction value decreases, and vice versa; similarly, the difference between 1 and the second proportion can be used as the weight corresponding to the clamping torque, thereby achieving the following: when the second variance increases, the second proportion increases, and the weight corresponding to the clamping torque decreases, and vice versa.

[0090] In this embodiment, the weight corresponding to the hill-holding torque correction value and the weight corresponding to the clamping torque are determined by utilizing the proportion of the first variance corresponding to the hill-holding torque correction value in the total variance and the proportion of the second variance corresponding to the clamping torque in the total variance; by subtracting the first proportion from 1 and the second proportion from 1, it is ensured that the weight decreases and increases as the data fluctuation degree increases, thereby ensuring that the determined hill-holding torque target value is more accurate.

[0091] In one embodiment, the “determining the dynamic value of the hill-holding torque required by the motor of the vehicle” in the above embodiment may include steps S301 to S304:

[0092] Step S301: When the preset vehicle mass estimation conditions are met, the vehicle speed change rate and the corresponding driving force are obtained.

[0093] Among them, the preset vehicle mass estimation condition can be a condition that represents that the current vehicle is in a stable state to meet the conditions for estimating the vehicle mass. For example, the vehicle should be in a non-slipping state. If the vehicle slips, it will affect the estimation of the vehicle mass. For example, if the vehicle slips, the corresponding driving force is high, but the vehicle speed change rate is 0. At this time, the vehicle mass cannot be estimated based on the vehicle speed change rate and the corresponding driving force.

[0094] Step S302: Determine the vehicle mass based on the linear regression analysis of the vehicle speed change rate and the corresponding driving force.

[0095] Step S303: Determine the slope of the road on which the vehicle is located.

[0096] Step S304: Determine the dynamic value of the hill-holding torque according to the vehicle mass and the road slope.

[0097] For example, the target value of the holding torque can be determined from the perspective of vehicle dynamics. Specifically, the dynamic value of the holding torque can be determined based on the vehicle mass and the road slope, taking the vehicle mass into consideration.

[0098] For example, in actual driving, the number of passengers and cargo carried by the vehicle varies, so the vehicle mass also varies. For this, the vehicle mass can be estimated. For example, the vehicle mass can be estimated by the vehicle speed change rate and the corresponding driving force, such as using the formula F=ma, where F is the driving force, a is the vehicle speed change rate, and m is the vehicle mass.

[0099] For example, since the rate of change of vehicle speed may not be a fixed value in actual driving, correspondingly, the driving force may not be a fixed value. Therefore, linear regression analysis can be used to determine the vehicle mass.

[0100] In this embodiment, the vehicle mass is estimated by linear regression analysis of the vehicle speed change rate and the corresponding driving force, which can improve the accuracy of the estimated vehicle mass; the dynamic value of the hill-holding torque is determined according to the vehicle mass and the road slope, thereby realizing the determination of the dynamic value of the hill-holding torque from the perspective of vehicle dynamics, and also helps to improve the accuracy of the dynamic value of the hill-holding torque.

[0101] In one of the embodiments, the vehicle hill-holding control method may further include: acquiring driving status information of the vehicle; determining that a preset vehicle mass estimation condition is met when the driving status information simultaneously satisfies the following conditions: the vehicle speed change rate is greater than a preset estimated vehicle speed change rate threshold; the vehicle's lateral acceleration is less than a preset estimated lateral acceleration threshold; the vehicle's steering wheel angle is less than a preset estimated steering wheel angle threshold; and the vehicle is in a non-slip state.

[0102] Among them, the preset estimated speed change rate threshold can be a value used to estimate the vehicle mass to measure whether the speed change rate meets the standard. It can be a specific value or a range. If the vehicle's speed change rate is too small, such as 0.001m / s², it means that the speed change is very small, and the corresponding actual situation of the vehicle may be that the vehicle is already stationary on the slope, so there is no need to perform the relevant steps; of course, the vehicle's speed change rate is too small, it may also correspond to the vehicle actually maintaining a certain speed, such as 20km / h. At this time, there is no need to stationary on the slope, and there is no need to perform the relevant steps. In addition, if the speed change rate is too small, it may not be possible to apply the aforementioned F=ma calculation formula, such as a=0m / s², and thus the vehicle mass cannot be estimated.

[0103] The lateral acceleration may be compared with the longitudinal acceleration, and the longitudinal acceleration may be determined based on the vehicle body orientation.

[0104] For example, if the vehicle has a large lateral acceleration, it may indicate that the vehicle has lateral movement, such as side slipping, etc. At this time, if the vehicle mass is estimated, there may be a large error, so the corresponding situation may not meet the preset vehicle mass estimation conditions. For example, with respect to the vehicle's steering wheel angle, similar to the aforementioned lateral acceleration, if the steering wheel angle is large, it may also be considered that the preset vehicle mass estimation conditions are not met.

[0105] Among them, the vehicle being in a non-skidding state can represent that the state of the vehicle is stable, and there is no reduction in friction between the vehicle tires and the road surface, which causes the vehicle to lose control of the driving direction.

[0106] For example, to ensure the validity and accuracy of the vehicle mass estimation, the preset vehicle mass estimation conditions may be determined to be met only when the above-mentioned multiple conditions are met at the same time, that is, the vehicle's current longitudinal speed is stable, the lateral acceleration is small, and the vehicle is not slipping.

[0107] In this embodiment, multiple aspects such as the vehicle speed change rate, lateral acceleration, steering wheel angle, non-slip state, etc. are used to determine whether the preset vehicle mass estimation conditions are met, thereby avoiding the situation where the vehicle mass estimation is performed when the above conditions are not met and the vehicle mass cannot be obtained or the vehicle mass is obtained with a large error, which helps to determine a more accurate target value of the hill-holding torque.

[0108] In one of the embodiments, the "determining the vehicle's overall mass based on a linear regression analysis of the vehicle speed change rate and the corresponding driving force" in the aforementioned embodiment may include: determining the vehicle's current estimated overall mass based on a linear regression analysis of the vehicle speed change rate and the corresponding driving force; determining the degree of fluctuation of multiple estimated vehicle masses within a set period; when the degree of fluctuation is less than or equal to a preset threshold, determining the current estimated vehicle mass as the vehicle's overall mass; when the degree of fluctuation is greater than a preset threshold, determining the preset vehicle mass as the vehicle's overall mass.

[0109] The preset threshold value can be broadly understood, and can be a specific value, such as 0.5, or a specific range, such as (0.5, 1). For example, the degree of fluctuation can be measured by setting a threshold value.

[0110] For example, the vehicle mass can be estimated by linear regression analysis of the vehicle speed change rate and the corresponding driving force to obtain the current estimated vehicle mass of the vehicle. Since the estimated vehicle mass may differ from the actual vehicle mass, the estimated vehicle mass can be corrected or reliability evaluated to further improve accuracy.

[0111] Exemplarily, the fluctuation degree of multiple estimated vehicle masses within a set period can be used to implement the reliability assessment of the estimated vehicle mass. For example, when the fluctuation degree of multiple estimated vehicle masses is large, from a data perspective, it means that the multiple estimated vehicle masses within the set period show instability, while the actual vehicle mass generally does not change, so the estimated vehicle mass reliability may be poor; conversely, it means that its reliability is good. Exemplarily, for poor reliability, the estimated vehicle mass can be not used, and the preset vehicle mass can be selected as the vehicle mass; for good reliability, the current estimated vehicle mass can be determined as the vehicle mass.

[0112] Exemplarily, the preset vehicle mass can be obtained from a pre-stored vehicle mass related database. For example, the vehicle mass under different conditions (such as slope, speed change rate) is obtained through experimental statistics to form a related database. Then, according to the current actual situation of the vehicle, the matching vehicle mass can be found in the database as the preset vehicle mass.

[0113] In this embodiment, the current estimated vehicle mass is determined based on the linear regression analysis of the vehicle speed change rate and the corresponding driving force, and the accuracy of the estimated vehicle mass is ensured by using the fluctuation degree of multiple estimated vehicle masses within a set period. If the fluctuation degree is small, the current estimated vehicle mass is determined as the vehicle mass; otherwise, the preset vehicle mass is determined as the vehicle mass. In this way, the final determined vehicle mass can be guaranteed to have good accuracy and avoid using the estimated vehicle mass with large errors.

[0114] In one of the embodiments, "determining the initial value of the hill-holding torque corresponding to the vehicle motor" in the aforementioned embodiment may include: when the vehicle speed is within a preset hill-holding speed range, determining the slope of the road on which the vehicle is located, and determining the initial value of the hill-holding torque corresponding to the road slope based on a preset slope-torque correspondence table.

[0115] The hill-holding speed range may be a speed range corresponding to the vehicle entering a hill-holding state. For example, when the vehicle's ground speed is within the range of [2, -2] kph, it can be considered that the vehicle speed is within the preset hill-holding speed range. Exemplarily, the hill-holding speed range corresponds to a relatively low speed, which is a low speed.

[0116] The slope torque correspondence table may be a table representing different torques required by the motor of the vehicle to make the vehicle stop on different road slopes. The slope torque correspondence table may be understood in a broad sense, and its form of expression is not limited to a table, but may also be other forms of expression, such as a database, etc. The slope torque correspondence table may be pre-stored in the vehicle, or stored in the cloud and acquired and updated by the vehicle communicating with the cloud.

[0117] For example, when it is detected that the vehicle speed is within the preset hill-holding speed range, it indicates that the vehicle needs to hold the hill. To this end, the road slope of the vehicle can be determined, and then the corresponding initial value of the hill-holding torque can be obtained from the slope torque correspondence table according to the road slope.

[0118] In the present embodiment, when the vehicle speed is within a preset hill-holding speed range, the corresponding hill-holding torque initial value is determined from the slope-torque correspondence table according to the road slope on which the vehicle is located, thereby enabling the hill-holding torque initial value to be quickly determined; at the same time, compared with the aforementioned determination of the hill-holding torque dynamic value (formula value) from the perspective of vehicle dynamics, the present embodiment determines the hill-holding torque initial value (table lookup value) from another perspective, thereby serving the subsequent steps of fusing the hill-holding torque dynamic value (formula value) with the hill-holding torque initial value (table lookup value) to obtain the hill-holding torque correction value, and helping to improve the accuracy of the determined hill-holding torque correction.

[0119] In an exemplary embodiment, Figure 4As shown, a vehicle holding hill control method is provided, and the method may include steps S401 to S409, which are specifically as follows:

[0120] Step S401: The vehicle controller VCU monitors the vehicle motor speed n, gear position, longitudinal acceleration a, vehicle mass m, and the maximum recovery torque available from the motor in real time.

[0121] The longitudinal acceleration a may be different from the aforementioned vehicle speed change rate. For example, the longitudinal acceleration a may be measured by a sensor of the vehicle, and the vehicle speed change rate may be determined by calculating the vehicle speed relative to the ground.

[0122] Step S402: Calculate the vehicle speed based on the motor speed. The basic principle can be reflected by the following calculation formula:

[0123] , where V is the vehicle speed, r is the tire radius, and i is the speed ratio. is the conversion factor from rotational speed to vehicle speed.

[0124] Step S403: Determine the vehicle driving direction V based on the motor speed Direction The basic principle is as follows:

[0125] The vehicle's driving direction is determined when any of the following conditions are met:

[0126] ① The vehicle speed is less than 5km / h; ② The vehicle's driving direction changes;

[0127] The specific vehicle driving direction is divided into forward and reverse. In some possible embodiments, the driving direction of the vehicle can be determined by the positive and negative of the motor speed, that is, forward and reverse. For example, a positive motor speed can correspond to a forward driving direction, and a negative motor speed can correspond to a reverse driving direction. For example, when the motor speed is less than -50rpm and the driving direction is reverse, V Direction Equal to -1, when the motor speed is greater than 50rpm, the driving direction is forward, V Direction Equal to 1. Of course, the motor speed threshold here can also take other values, such as -10rpm, 100rpm, etc. There is no restriction here. To ensure the accuracy of the judgment, the threshold is generally not close to 0.

[0128] Step S404: Calculate the vehicle speed relative to the ground based on the driving direction and the motor speed, which is used to subsequently determine whether the vehicle is driving in the reverse direction.

[0129] The basic principle can be reflected by the following calculation formula:

[0130] V Ground =V×V Direction , where V Ground is the vehicle speed over the ground, V DirectionThe direction of vehicle travel.

[0131] Step S405: Determine whether the function flag is activated based on the button, throttle, and vehicle speed relative to the ground.

[0132] Among them, the button can be a physical button, for example, it can be similar to the emergency light button of the vehicle, or it can be a virtual button, such as a virtual button displayed on the vehicle display screen. In an embodiment of the present application, the button can be associated with the opening and closing of the motor hill-holding function. For example, when the driver presses the button, it indicates that the motor needs to be used for hill-holding, so the function flag corresponding to the motor hill-holding function is activated. Exemplarily, the button can also be the existing buttons of the vehicle, such as the wiper button, the emergency light button, etc.

[0133] This step corresponds to the "activation of the vehicle's motor hill-holding function" and other related contents in the aforementioned embodiment. The basic principle is as follows:

[0134] Function activation condition: If the driver frequently presses the button for more than the set time threshold of 1 second, it means that there is a need to decelerate. Of course, the activation condition can also be other conditions. For example, when the driver presses the button multiple times in a short period of time, such as pressing the emergency light button three times in a row, the flag of the motor holding function is activated.

[0135] Function exit conditions: The driver's accelerator opening is greater than 20% or the vehicle speed relative to the ground is less than -5km / h. When the driver steps on the accelerator, it means that there is a need for acceleration. When the vehicle speed relative to the ground is less than -5km / h, it means that the vehicle has accelerated in the reverse direction. In order to avoid unexpected movement, this function needs to be forcibly exited.

[0136] Step S406: Calculate the initial value of the hill-holding torque based on the function flag, the vehicle speed relative to the ground, and the slope.

[0137] When the function flag is activated and the driver requires the vehicle to remain stationary, the initial value of the hill-holding torque needs to be calculated:

[0138] When the vehicle speed relative to the ground is within the set range threshold [2,-2] kph, it is in the hill-holding state. The hill-holding torque is calculated as follows:

[0139] When in the stationary slope state, the initial value is calculated by looking up the table with the slope as the horizontal coordinate.

[0140] Step S407: Calculate the dynamic value of the hill-holding torque based on the load and the slope.

[0141] When all of the following conditions are met, the value can be estimated by kinetics. A possible specific calculation formula is provided below:

[0142] T dynamic =m×g×sinθ, where m is the load of the vehicle, θ is the slope of the vehicle, g is the gravity coefficient, and Tdynamic It is the dynamic value of the hill-holding torque.

[0143] To improve the accuracy of load estimation, the following conditions can be set to estimate the load. If the following conditions are met, load estimation is allowed:

[0144] 1. The absolute value of the vehicle speed change rate is greater than the set threshold;

[0145] 2. The absolute value of the lateral acceleration is less than the threshold;

[0146] 3. The absolute value of the steering wheel angle is less than the threshold;

[0147] 4. The vehicle is in a stable state, i.e. not slipping.

[0148] When all the above conditions are met, the load is estimated by the least square method based on m=F / a in combination with the vehicle driving equation. This corresponds to "determining the vehicle's mass based on the linear regression analysis of the vehicle speed change rate and the corresponding driving force" and other related content. The load can correspond to the vehicle's mass.

[0149] In order to improve the accuracy of the dynamic value of the hill-holding torque, it is possible to determine whether to update the dynamic value of the hill-holding torque based on the variance value of the estimated load. If the variance value of the load is greater than the set threshold, it is considered that the estimated load is inaccurate and no subsequent calculations are performed. Otherwise, the value (estimated load) is used as a subsequent control to calculate the corresponding dynamic value of the hill-holding torque based on multiple estimated loads, and calculate the average value of multiple dynamic values ​​of the hill-holding torque within a set period to obtain the dynamic average value of the hill-holding torque. The variance value of multiple dynamic values ​​of the hill-holding torque can also be calculated.

[0150] Step S408: Calculate the hill-holding torque 1, i.e., the "hill-holding torque correction value", based on the initial value, the dynamic average value of the hill-holding torque, and the vehicle speed change rate. This corresponds to "determining the hill-holding torque correction value based on the initial value of the hill-holding torque and the dynamic value of the hill-holding torque" and other related contents.

[0151] The basic principle is as follows: when the variance of the dynamic value of the holding torque is less than the threshold, the confidence of the dynamic average value of the holding torque is considered to be higher. Set the target variance value, and calculate the confidence based on the current actual variance value and the target variance value of the dynamic value of the holding torque. The corresponding calculation formula is as follows:

[0152] n=1-(XX target ) / X, where n represents the confidence level, X represents the current actual variance value of the dynamic value of the ramp-holding torque, and X target Represents the target variance value.

[0153] After determining the confidence level, the initial value and the dynamic average value of the on-hill torque can be weighted based on the confidence level to calculate the on-hill torque 1. This value is equal to the confidence level multiplied by the dynamic average value of the on-hill torque plus 1-confidence level multiplied by the initial value. Exemplarily, the initial value is calculated based on the slope lookup table, and the dynamic average value of the on-hill torque is calculated based on the formula. If the variance of the dynamic value of the on-hill torque is small, it means that the dynamic average value of the on-hill torque is more accurate. Here 1 represents 100%. For example, if the confidence level is 60%, it is equal to 60%×dynamic average of the on-hill torque+(1-60%)×initial value. This value is on-hill torque 1.

[0154] At the same time, the confidence level can also be corrected in combination with the vehicle speed change rate. If the vehicle speed change rate increases under this confidence level, the dynamic average ratio of the hill-holding torque should be reduced to reduce the confidence level. If the vehicle speed change rate decreases under this confidence level, the dynamic average ratio of the hill-holding torque should be increased to increase the confidence level.

[0155] Step S409: Calculate the hill-holding torque based on the clamping torque. When the hill-holding function is activated by the braking system, the final hill-holding torque, i.e., the hill-holding torque target value, is calculated by observing the clamping torque. Fusion is achieved by comparing the hill-holding torque 1 and the clamping torque variance value under the same slope. This corresponds to "determining the hill-holding torque target value required by the vehicle motor based on the clamping torque and the hill-holding torque correction value" and other related content.

[0156] The basic principle is as follows: the final torque is equal to the ramp torque 1×[1-slope torque 1 variance value ÷ (slope torque 1 variance value + clamping torque variance value)]+clamping torque×[1-clamping torque variance value ÷ (slope torque 1 variance value + clamping torque variance value)]. For example, the ramp torque 1 is A, the ramp torque 1 variance value is A1, the clamping torque is B, the clamping torque variance value is B1, and the final torque is C, then C=A·(1-A1 / (A1+B1))+B·(1-B1 / (A1+B1))=A·(B1 / (A1+B1))+B·(A1 / (A1+B1)).

[0157] The implementation of the above technical solution can be based on the principle of motor stalling. Motor stalling is a situation where the motor still outputs torque when the speed is 0. There is a corresponding relationship between the motor speed and the vehicle speed. The vehicle speed can be calculated by the wheel speed or the motor speed. The deceleration is generated by electric braking to slow down the vehicle or even stop it.

[0158] In this embodiment, when the vehicle's hill-holding function is activated, the basic value of the stall torque is calculated in two ways: by looking up the slope table at low speed, that is, determining the initial value of the hill-holding torque; by calculating the dynamic formula, and establishing a calculation and update mechanism for the quality factor in the formula, that is, determining the dynamic value of the hill-holding torque. The weight is calculated by combining the variance of the dynamically calculated value to achieve the fusion of the table lookup value and the formula value. At the same time, the technical solution of this embodiment can compare the braking torque under different slopes in the past, record the braking torque, and compare it with the hill-holding torque after the function is activated, so as to obtain a more accurate hill-holding torque target value, which in turn helps to ensure that the vehicle can hold the hill more accurately by controlling the motor. The above technical solution combines dynamics and kinematics to solve the shortcomings of kinematic pitch angle error and poor dynamic real-time performance, and at the same time requires external torque, such as clamping torque, to ensure accuracy.

[0159] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0160] Based on the same inventive concept, the embodiment of the present application also provides a vehicle holding hill control device for implementing the vehicle holding hill control method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more embodiments of the vehicle holding hill control device provided below can refer to the limitations of the vehicle holding hill control method above, and will not be repeated here.

[0161] In an exemplary embodiment, Figure 5 As shown, a vehicle hill-holding control device 500 is provided, comprising:

[0162] The first determination module 501 is used to determine the initial value of the hill-holding torque and the dynamic value of the hill-holding torque corresponding to the motor of the vehicle when the hill-holding function of the motor of the vehicle is activated;

[0163] A second determination module 502 is used to determine a hill-holding torque correction value based on the hill-holding torque initial value and the hill-holding torque dynamic value;

[0164] The third determination module 503 is used to obtain the clamping torque recorded for the vehicle during the hill-holding process, and determine the hill-holding torque target value based on the clamping torque and the hill-holding torque correction value;

[0165] The hill-holding control module 504 is used to control the vehicle motor based on the hill-holding torque target value to make the vehicle hold the hill.

[0166] In this embodiment, the first determination module of the vehicle hill-holding control device determines the initial value of the hill-holding torque and the dynamic value of the hill-holding torque corresponding to the vehicle motor when the motor hill-holding function is activated, and the second determination module of the vehicle hill-holding control device determines the hill-holding torque correction value according to the initial value of the hill-holding torque and the dynamic value of the hill-holding torque. This can make a timely response in the hill-holding process and obtain a more accurate hill-holding torque correction value. In addition, the third determination module of the vehicle hill-holding control device comprehensively determines the hill-holding torque target value according to the clamping torque and the hill-holding torque correction value of the hill-holding process recorded by the vehicle, which makes the obtained hill-holding torque target value more matched with the current vehicle situation. Therefore, the hill-holding control module of the vehicle hill-holding control device controls the vehicle motor according to the hill-holding torque target value, which can achieve more accurate hill-holding of the current vehicle and avoid hill-holding failure caused by excessive or too small hill-holding torque target value. At the same time, it can achieve the vehicle hill-holding in the case of vehicle brake failure, thereby ensuring driving safety.

[0167] In one embodiment, the second determination module 502 is further used to determine the hill-holding torque correction value based on the hill-holding torque initial value and the hill-holding torque dynamic value, including: determining a first confidence level of the hill-holding torque dynamic value based on the degree of fluctuation of the hill-holding torque dynamic value within a preset period; determining a second confidence level corresponding to the hill-holding torque initial value according to the first confidence level; the sum of the first confidence level and the second confidence level is 1; and merging the hill-holding torque initial value and the hill-holding torque dynamic value according to the first confidence level and the second confidence level to obtain the hill-holding torque correction value.

[0168] In one embodiment, the second determination module 502 is further used to determine a first confidence level of the dynamic value of the hill-holding torque based on the degree of fluctuation of the dynamic value of the hill-holding torque within a preset period, including: determining an initial confidence level of the dynamic value of the hill-holding torque; determining the initial confidence level based on the difference between actual variance values ​​corresponding to multiple dynamic values ​​of the hill-holding torque within a preset period and a preset target variance value; obtaining a speed change rate of the vehicle under the control of the dynamic value of the hill-holding torque with the initial confidence level; based on the speed change rate, correcting the initial confidence level to obtain a first confidence level of the dynamic value of the hill-holding torque; wherein, when the speed change rate increases, the initial confidence level is reduced; when the speed change rate decreases, the initial confidence level is increased.

[0169] In one embodiment, the third determination module 503 is also used to determine the target hill-holding torque required by the vehicle motor based on the clamping torque and the hill-holding torque correction value, including: obtaining the slope value range corresponding to the hill-holding torque correction value, and obtaining the clamping torque corresponding to the same slope value range; obtaining the first variance of the hill-holding torque correction value and the second variance of the clamping torque; determining the weights corresponding to the hill-holding torque correction value and the clamping torque respectively according to the first variance and the second variance; based on the weight, fusing the hill-holding torque correction value and the clamping torque to obtain the target hill-holding torque.

[0170] In one embodiment, the third determination module 503 is also used to determine the weights corresponding to the hill-holding torque correction value and the clamping torque respectively according to the first variance and the second variance, including: determining the sum of the first variance and the second variance as the total variance; determining the proportion of the first variance to the total variance as the first proportion, and the proportion of the second variance to the total variance as the second proportion; determining the weights corresponding to the hill-holding torque correction value and the clamping torque respectively according to the first proportion and the second proportion; wherein the weight corresponding to the hill-holding torque correction value is negatively correlated with the first proportion, and the weight corresponding to the clamping torque is negatively correlated with the second proportion.

[0171] In one embodiment, the first determination module 501 is also used to determine the dynamic value of the hill-holding torque required by the vehicle's motor, including: obtaining the vehicle speed change rate and the corresponding driving force of the vehicle when the preset vehicle mass estimation conditions are met; determining the vehicle mass based on a linear regression analysis of the vehicle speed change rate and the corresponding driving force; determining the slope of the road on which the vehicle is located; and determining the dynamic value of the hill-holding torque based on the vehicle mass and the road slope.

[0172] In one of the embodiments, the first determination module 501 is also used to obtain driving state information of the vehicle; when the driving state information satisfies the following conditions, it is determined that the preset vehicle mass estimation conditions are met: the vehicle speed change rate is greater than a preset estimated vehicle speed change rate threshold; the vehicle's lateral acceleration is less than a preset estimated lateral acceleration threshold; the vehicle's steering wheel angle is less than a preset estimated steering wheel angle threshold; and the vehicle is in a non-slip state.

[0173] In one of the embodiments, the first determination module 501 is also used to determine the vehicle mass based on a linear regression analysis of the vehicle speed change rate and the corresponding driving force, including: determining the current estimated vehicle mass based on a linear regression analysis of the vehicle speed change rate and the corresponding driving force; determining the degree of fluctuation of multiple estimated vehicle masses within a set period; when the degree of fluctuation is less than or equal to a preset threshold, determining the current estimated vehicle mass as the vehicle mass; when the degree of fluctuation is greater than a preset threshold, determining the preset vehicle mass as the vehicle mass.

[0174] In one embodiment, the first determination module 501 is also used to determine the initial value of the hill-holding torque corresponding to the vehicle motor, including: when the vehicle speed is within a preset hill-holding speed range, determining the slope of the road on which the vehicle is located, and determining the initial value of the hill-holding torque corresponding to the road slope based on a preset slope-torque correspondence table.

[0175] Each module in the above-mentioned vehicle hill-holding control device 500 can be implemented in whole or in part by software, hardware, or a combination thereof. Each of the above-mentioned modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each of the above modules.

[0176] In an exemplary embodiment, a new energy vehicle is provided, and its internal structure diagram can be as follows: Figure 6 As shown. The new energy vehicle includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the new energy vehicle is used to provide computing and control capabilities. The memory of the new energy vehicle includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the new energy vehicle is used to store data required for vehicle hill-holding control, for example, the clamping torque and other related data recorded by the vehicle during the hill-holding process. The input / output interface of the new energy vehicle is used to exchange information between the processor and the external device. The communication interface of the new energy vehicle is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a vehicle hill-holding control method is implemented.

[0177] Those skilled in the art will understand that Figure 6 The structure shown in the figure is only a block diagram of a part of the structure related to the scheme of the present application, and does not constitute a limitation on the new energy vehicle to which the scheme of the present application is applied. A specific new energy vehicle may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0178] In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0179] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0180] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0181] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0182] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0183] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A vehicle holding hill control method, characterized in that: The method comprises: When the motor holding hill function of the vehicle is activated, determining an initial holding hill torque value and a dynamic holding hill torque value corresponding to the motor of the vehicle; Determining a hill-holding torque correction value based on the hill-holding torque initial value and the hill-holding torque dynamic value; Obtaining a recorded clamping torque during the hill-holding process of the vehicle; Obtaining a slope value range corresponding to the hill-holding torque correction value, and obtaining the clamping torque corresponding to the same slope value range; Obtaining a first variance of the hill-holding torque correction value and a second variance of the clamping torque; Determining weights corresponding to the hill-holding torque correction value and the clamping torque, respectively, according to the first variance and the second variance; Based on the weight, the hill-holding torque correction value is integrated with the clamping torque to obtain the hill-holding torque target value; The vehicle motor is controlled based on the hill-holding torque target value to make the vehicle hold the hill.

2. The method according to claim 1, characterized in that The determining of the hill-holding torque correction value based on the hill-holding torque initial value and the hill-holding torque dynamic value comprises: Determining a first confidence level of the dynamic value of the hill-holding torque based on a fluctuation degree of the dynamic value of the hill-holding torque within a preset period; Determining a second confidence level corresponding to the initial value of the hill-holding torque according to the first confidence level; the sum of the first confidence level and the second confidence level is 1; The hill-holding torque initial value and the hill-holding torque dynamic value are merged according to the first confidence level and the second confidence level to obtain the hill-holding torque correction value.

3. The method according to claim 2, characterized in that The determining of the first confidence level of the dynamic value of the hill-holding torque based on the fluctuation degree of the dynamic value of the hill-holding torque within a preset period includes: Determining an initial confidence level of the dynamic value of the hill-holding torque; the initial confidence level is determined based on a difference between actual variance values ​​corresponding to a plurality of the dynamic values ​​of the hill-holding torque within a preset period and a preset target variance value; Acquiring a speed change rate of the vehicle under control of the dynamic value of the hill-holding torque at the initial confidence level; Based on the vehicle speed change rate, the initial confidence is corrected to obtain a first confidence of the dynamic value of the hill-holding torque; wherein, when the vehicle speed change rate increases, the initial confidence is reduced; and when the vehicle speed change rate decreases, the initial confidence is increased.

4. The method according to claim 1, characterized in that The step of determining the weights corresponding to the hill-holding torque correction value and the clamping torque according to the first variance and the second variance includes: determining a sum of the first variance and the second variance as a total variance; Determine a first proportion of the first variance relative to the total variance and a second proportion of the second variance relative to the total variance; According to the first proportion and the second proportion, the weights corresponding to the hill-holding torque correction value and the clamping torque are determined respectively; wherein the weight corresponding to the hill-holding torque correction value is negatively correlated with the first proportion, and the weight corresponding to the clamping torque is negatively correlated with the second proportion.

5. The method according to claim 1, characterized in that The step of determining the dynamic value of the hill-staying torque required by the motor of the vehicle comprises: When a preset vehicle mass estimation condition is met, obtaining a vehicle speed change rate and a corresponding driving force of the vehicle; Determining the vehicle mass of the vehicle based on a linear regression analysis of the vehicle speed change rate and the corresponding driving force; determining the slope of the road on which the vehicle is located; The dynamic value of the hill-holding torque is determined according to the vehicle mass and the road slope.

6. The method according to claim 5, characterized in that The method further comprises: Acquiring driving status information of the vehicle; When the driving state information satisfies the following conditions at the same time, it is determined that the preset vehicle mass estimation condition is met: The vehicle speed change rate is greater than a preset estimated vehicle speed change rate threshold; The lateral acceleration of the vehicle is less than a preset estimated lateral acceleration threshold; The steering wheel angle of the vehicle is less than a preset estimated steering wheel angle threshold; The vehicle is in a non-slip state.

7. The method according to claim 5, characterized in that The determining the vehicle mass of the vehicle based on the linear regression analysis of the vehicle speed change rate and the corresponding driving force includes: Determining a current estimated vehicle mass of the vehicle based on a linear regression analysis of the vehicle speed change rate and the corresponding driving force; Determining a degree of fluctuation of a plurality of the estimated vehicle masses within a set period; When the fluctuation degree is less than or equal to a preset threshold, determining the current estimated vehicle mass as the vehicle mass; When the fluctuation degree is greater than the preset threshold, the preset vehicle mass is determined as the vehicle mass.

8. The method according to any one of claims 1 to 7, characterized in that: The step of determining an initial value of the hill-holding torque corresponding to the motor of the vehicle includes: When the vehicle speed is within a preset hill-holding speed range, the road slope of the vehicle is determined, and based on a preset slope-torque correspondence table, an initial hill-holding torque value corresponding to the road slope is determined.

9. A vehicle holding hill control device, characterized in that: The device comprises: A first determination module is used to determine an initial value of the hill-holding torque and a dynamic value of the hill-holding torque corresponding to the motor of the vehicle when the hill-holding function of the motor of the vehicle is activated; A second determination module is used to determine a hill-holding torque correction value based on the hill-holding torque initial value and the hill-holding torque dynamic value; A third determination module is used to obtain the clamping torque recorded for the vehicle during the hill-holding process; obtain the slope value range corresponding to the hill-holding torque correction value, and obtain the clamping torque corresponding to the same slope value range; obtain the first variance of the hill-holding torque correction value and the second variance of the clamping torque; determine the weights corresponding to the hill-holding torque correction value and the clamping torque respectively according to the first variance and the second variance; based on the weights, merge the hill-holding torque correction value and the clamping torque to obtain the hill-holding torque target value; The hill-holding control module is used to control the vehicle motor based on the hill-holding torque target value to make the vehicle stay on the hill.

10. A new energy vehicle, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.

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