Vehicle driving control method and device

Abstract

The invention provides a vehicle driving control method and device, relates to the technical field of electric vehicle control, and can initiate a position control request and input the current request to control the target driving distance of a vehicle when the vehicle is in a specific driving mode, and control the target driving distance of the vehicle when a vehicle controller responds to the position control request. The method comprises the following steps: directly utilizing a wheel speed sensor and a rotation angle sensor of each wheel configured on a vehicle to obtain corresponding rotation speed information and rotation angle information of each wheel in a current control period, accurately estimating a current driving distance obtained by accumulating the vehicle to the current control period, and if the current driving distance is determined not to be matched with a target driving distance, determining that the vehicle is not matched with the target driving distance. When the vehicle runs in the specific running mode, running control of the next control period needs to be executed continuously, at the moment, the driving motor torque of the vehicle in the next control period is adjusted, minimum stable vehicle speed control is achieved, it is guaranteed that the vehicle in the specific running mode can run continuously, safely and stably, and the comfort of passengers is improved.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicle control, and more specifically to a vehicle driving control method and device. Background Art

[0002] Electric vehicles are vehicles that use an onboard power source as their power source, an electric motor to drive their wheels, and comply with all road traffic and safety regulations. During autonomous driving, parking, or navigation, electric vehicles typically use sensors such as radar or the Global Positioning System (GPS) to estimate their driving position and control the vehicle's position.

[0003] However, in low-speed driving mode, the vehicle's driving position estimated based on radar or GPS sensors is inaccurate and cannot be accurately controlled to ensure safe and stable driving of the low-speed vehicle. Summary of the Invention

[0004] In view of the above problems, this application provides the following solutions:

[0005] In a first aspect, the present application provides a vehicle driving control method, the vehicle driving control method comprising:

[0006] In response to a position control request for a vehicle in a specific driving mode, obtaining a target driving distance of the vehicle; the specific driving mode includes a low-speed driving mode and a starting mode;

[0007] Obtaining a current travel distance of the vehicle based on speed information and rotation angle information corresponding to each wheel of the vehicle; the speed information is obtained based on output changes of wheel speed sensors of corresponding wheels within a current control cycle;

[0008] It is determined that the current driving distance does not match the target driving distance, and by adjusting the driving motor torque of the vehicle in the next control cycle, the driving speed change of the vehicle in the specific driving mode is controlled to be less than a vehicle speed change threshold, and the absolute value of the driving speed is less than a vehicle speed threshold.

[0009] A second aspect of the present application provides a vehicle driving control device, the vehicle driving control device comprising:

[0010] a target driving distance acquisition module, configured to acquire a target driving distance of the vehicle in response to a position control request for a vehicle in a specific driving mode; the specific driving mode includes a low-speed driving mode and a starting mode;

[0011] a current travel distance acquisition module, configured to acquire the current travel distance of the vehicle based on the rotational speed information and rotational angle information corresponding to each wheel of the vehicle; the rotational speed information is obtained based on the output change of the wheel speed sensor of the corresponding wheel within the current control cycle;

[0012] a drive motor torque adjustment module, configured to determine that the current driving distance does not match the target driving distance, and to adjust the drive motor torque of the vehicle in the next control cycle so that a change in the driving speed of the vehicle in the specific driving mode is less than a vehicle speed change threshold, and an absolute value of the driving speed is less than a vehicle speed threshold.

[0013] It can be seen that the present application proposes a vehicle driving control method and device, which relates to the field of control technology of electric vehicles. When the vehicle is in a specific driving mode, a position control request can be initiated, and the target driving distance of the vehicle requested to be controlled this time is input. During the period when the vehicle controller responds to the position control request, there is no need to configure additional sensors. The wheel speed sensors and angle sensors of each wheel already configured on the vehicle are directly used to obtain the corresponding speed information and angle information of each wheel in the current control cycle, and the current driving distance accumulated by the vehicle to the current control cycle is accurately estimated based on this. If it is determined that the current driving distance does not match the target driving distance, it is necessary to continue the driving control of the next control cycle. At this time, the minimum stable vehicle speed control will be achieved by adjusting the driving motor torque of the vehicle in the next control cycle, ensuring that the vehicle in the specific driving mode can continue to drive safely and stably, thereby improving the comfort of the passengers. In this way, the vehicle position is gradually adjusted through multiple control cycles, which better meets the precise positioning requirements in scenarios such as automatic driving, parking or navigation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The above and other features, advantages, and aspects of the various embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and that the originals and elements are not necessarily drawn to scale.

[0015] Figure 1 A flow chart of a vehicle driving control method proposed in Example 1 of the present application;

[0016] Figure 2 A flow chart of a vehicle driving control method proposed in Example 2 of the present application;

[0017] Figure 3 This is a flow chart of a vehicle driving control method proposed in Example 3 of the present application;

[0018] Figure 4A flow chart of a vehicle driving control method provided in an embodiment of the present application;

[0019] Figure 5 A schematic diagram of a signal interface for implementing a vehicle driving control method proposed in an embodiment of the present application;

[0020] Figure 6 This is a flow chart of a vehicle driving control method proposed in Example 4 of the present application;

[0021] Figure 7 A schematic structural diagram of a vehicle driving control device provided in an embodiment of the present application;

[0022] Figure 8 The figure is a schematic structural diagram of an optional embodiment of a vehicle controller suitable for the vehicle driving control method proposed in this application. DETAILED DESCRIPTION

[0023] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application. The terms used in the implementation methods section of this application are only used to explain the specific embodiments of the present application and are not intended to limit this application. The embodiments of the present application are described below in conjunction with the drawings. It is known to those skilled in the art that with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0024] The terms "first", "second" etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, and this is merely a way of distinguishing the objects of identical properties when describing them in the embodiments of the present application. "If" can be interpreted as "at the time of" or "when" or "in response to determining" etc., and can be understood according to the context. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, so that the process, method, product or equipment comprising a series of units need not be limited to those units, but may include other units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0025] To address the technical issues described in the background section and improve vehicle positioning accuracy, the use of Differential GPS (DGPS) technology to obtain more accurate vehicle location information has been proposed. However, this technology is very expensive, including hardware acquisition costs, service fees, and communication costs, making it a poor choice for ordinary users. Furthermore, with the development and application of artificial intelligence (AI) technology, AI can also be used to analyze image data captured by image sensors (such as cameras) to determine the vehicle's driving position. However, this requires a large amount of computation and may not meet real-time control requirements. It also cannot cover all vehicle driving conditions and cannot be directly deployed in the vehicle controller, requiring additional installation by the user, which is quite cumbersome.

[0026] Furthermore, especially in electric vehicles without sensors like those mentioned above, it's possible to estimate distance traveled and achieve precise control of the vehicle's position by integrating the vehicle's engine / motor speed or by estimating vehicle speed using the chassis system. However, the long-term integration of these two methods leads to a gradual accumulation of position estimation errors, which reduces response speed and necessitates regular position calibration to compensate for integration errors and ensure accurate position estimation, which is very cumbersome. Furthermore, the method for estimating position based on motor speed integration cannot estimate the vehicle's position during a slippery start; and integrating the chassis system's estimated speed cannot accurately determine the vehicle's position during low-speed driving conditions.

[0027] To further improve this problem, the present application proposes a vehicle driving control method that uses the signals collected by low-cost wheel speed sensors (such as Hall sensors) and angle sensors installed on each wheel of the vehicle to estimate the vehicle's travel distance. By controlling the vehicle's drive motor torque, the electric vehicle can accurately control the vehicle's travel distance even in specific driving modes such as low-speed driving conditions or starting and sliding conditions, ensuring the driving safety and stability of the electric vehicle, and better suited for application scenarios such as autonomous driving, parking, or various navigation. The following is a detailed description of the variable angle transmission ratio control method of the present application embodiment with reference to the accompanying drawings.

[0028] Reference Figure 1, is a flow chart of a vehicle driving control method proposed in the first embodiment of the present application. The vehicle driving control method can be applied to the vehicle control system configured for electric vehicles (hereinafter referred to as vehicles), and can be executed by one or more vehicle controllers in the vehicle control system, such as the vehicle control unit (VCU), motor control unit (MCU) or all-in-one controller (an integrated circuit of multiple functional modules), central domain controller CCU (Central Control Unit), and power chassis domain controller. This application does not elaborate on the composition structure of the vehicle control system and the connection relationship between the vehicle controller and other components (such as parking brakes, drive motors, etc.). Based on this, Figure 1 As shown, the vehicle driving control method proposed in this embodiment may include but is not limited to the following steps:

[0029] Step S11, in response to a position control request for a vehicle in a specific driving mode, obtaining a target driving distance of the vehicle; the specific driving mode includes a low-speed driving mode and a starting mode;

[0030] In the present application, the position control request can be a trigger instruction for the vehicle to start executing a computer program that implements the vehicle driving control method proposed in the embodiment of the present application. It can be automatically or manually initiated in specific driving modes such as low-speed driving conditions (also known as low-speed driving mode, which can usually be defined in combination with multiple factors such as traffic regulations, vehicle design and driving environment, usually indicating that the vehicle is traveling within a lower speed range. This application does not limit this speed range) or starting conditions (also known as starting mode, that is, the process of the vehicle starting to move from a stationary state). This application does not limit the method of obtaining the position control request.

[0031] Therefore, when the vehicle controller receives the above-mentioned position control request and determines that the vehicle currently needs to be automatically controlled according to the method proposed in the embodiment of the present application, when responding to the position control request, it can first obtain the target driving distance that the vehicle currently needs to be controlled according to the method. The target driving distance refers to the driving distance starting from the position of the vehicle when responding to the position control request (such as taking the position as the initial driving distance, that is, initialized to 0), which can be expressed as: S d , which can be in meters (m), such as 10m. The target driving distance can be flexibly configured based on the control requirements of the actual scenario, and is usually a shorter distance. This application does not limit the value of the target driving distance obtained in step S11. It can be input by the driver or a default value configured by the vehicle control system for the current control scenario (such as autonomous driving scenario, parking scenario, or low-speed cruising scenario).

[0032] Based on this, step S11 may include but is not limited to any of the following implementations:

[0033] Method 1: In response to an input operation on the vehicle control panel, determine the position control flag and the target driving distance for the vehicle; the position control flag indicates whether to initiate a position control request for the vehicle, such as S f =0 means that the vehicle position control request is not initiated, or the position control request for the response is ended; S f =1 indicates initiating a vehicle position control request. The vehicle's control panel can be displayed on an onboard display device to facilitate the driver to directly complete the aforementioned input operations. Alternatively, it can be displayed on a remote terminal device that is directly or indirectly connected to the vehicle control system to facilitate an operator to remotely control the vehicle through the remote terminal device. For example, using the remote terminal device to log into the vehicle control system, display the vehicle's control panel to perform input operations, and thus remotely control the vehicle.

[0034] Method 2: In an automatic parking scenario, a position control request and a target driving distance sent by the vehicle's parking controller can be received; the target driving distance represents the driving distance of the vehicle in parking mode, which can be determined based on the parking environment information detected by the sensor.

[0035] Method three: In an autonomous driving scenario, a position control request and a target driving distance sent by the vehicle's autonomous driving controller can be received; the target driving distance indicates the driving distance of the vehicle in autonomous driving mode, etc.

[0036] Step S12, obtaining the current travel distance of the vehicle based on the speed information and rotation angle information corresponding to each wheel of the vehicle; the speed information is obtained based on the output change of the wheel speed sensor of the corresponding wheel during the current control cycle;

[0037] In practical applications of this application, to ensure vehicle driving control stability and maneuverability, the vehicle's drive motor torque can be periodically adjusted during the response to position control requests to achieve vehicle driving distance control, such as once every 10ms (milliseconds). This application does not restrict the size of each control cycle or its configuration. These cycles can be determined based on factors such as the acquired target driving distance and driving mode to meet vehicle driving control requirements. Optionally, during this control process, the control cycle size can be dynamically adjusted based on actual changes, so that the next control cycle is executed according to the adjusted control cycle.

[0038] Since the target driving distance obtained when responding to the position control request for the vehicle is the expected distance for the vehicle to be controlled from its current position, the present application can achieve the target driving distance through multiple accumulated driving distance controls. In this implementation process, compared with estimating the vehicle's driving distance by detecting the driving speed of the entire vehicle and the steering wheel angle, the present application takes into account that during the actual driving process of the vehicle, the actual driving conditions of the vehicle are jointly determined by the speed information and steering angle information of each wheel of the vehicle, and that there are often certain differences in information such as the speed and rotation angle of different wheels. Changes in the speed information and / or steering angle information of each wheel may directly affect the accuracy of the estimated driving distance of the entire vehicle. Therefore, the present application proposes to achieve a more accurate estimation of the vehicle's driving distance by detecting the speed information and steering angle information of each wheel in the vehicle.

[0039] Among them, the rotational speed information of each wheel can be obtained by the output change of the wheel speed sensor installed in the vehicle for detecting the rotational speed of the wheel. The wheel speed sensor may include but is not limited to: a magnetoelectric / resistive wheel speed sensor, a Hall-type wheel speed sensor (i.e., a Hall sensor), an eddy current wheel speed sensor or a photoelectric wheel speed sensor, etc. The implementation method of how to obtain the rotational speed information of the corresponding wheel based on the wheel speed sensor can be determined according to the working principle of the wheel speed sensor, and will not be described in detail in this application.

[0040] Regarding the steering angle information of each wheel, in one possible implementation, a steering angle sensor, such as an optical / electromagnetic / piezoelectric steering angle sensor, mounted on or around the corresponding wheel steering mechanism can be used to detect the wheel rotation angle of the corresponding wheel in real time. The implementation process can be determined based on the working principle of the corresponding type of steering angle sensor and is not described in detail in the embodiments of this application. It should be noted that when the wheels do not require four-wheel steering, the steering angles of the two rear wheels are zero, and the steering angle information of these two wheels does not need to be collected. Therefore, the wheels in step S12 refer to the wheels involved in the steering operation.

[0041] Optionally, if the vehicle is not equipped with the wheel angle sensor as described above, the steering wheel angle can be collected through the vehicle's steering wheel angle sensor. Then, based on the steering system parameters and the steering wheel angle, the angle of each wheel involved in the steering operation in the vehicle is calculated. The calculation process is not described in detail in this application.

[0042] It should be noted that this application does not restrict the type and installation location of the wheel speed sensors and rotation angle sensors corresponding to each wheel in the vehicle, and these can be determined based on the specific situation. Thus, for vehicles with different configurations, the wheel speed sensors and rotation angle sensors actually installed in the vehicle can be directly used to implement the method proposed in the embodiments of this application, without the user having to install additional sensors to meet the vehicle speed and steering detection requirements.

[0043] Based on the above analysis, during the response to a position control request, the speed and angle information corresponding to each wheel generated during each control cycle can be read at the end of each control cycle. This information can be used to more accurately estimate the cumulative distance traveled by the vehicle at the end of that control cycle. This distance can be recorded as the vehicle's current distance traveled during that control cycle, i.e., the distance between the vehicle's position at the time of the position control request response and the vehicle's position at the end of that control cycle. Thus, as the control cycles increase, the current distance obtained will continue to increase iteratively (i.e., cumulatively). The present application does not address how to estimate the vehicle's current distance traveled based on the speed and angle information corresponding to each wheel of the vehicle.

[0044] Step S13, determining that the current driving distance does not match the target driving distance, and controlling the vehicle's driving speed change in a specific driving mode to be less than a vehicle speed change threshold, and the absolute value of the driving speed to be less than a vehicle speed threshold by adjusting the driving motor torque of the vehicle in the next control cycle.

[0045] Combined with the above description of the estimated current driving distance of the vehicle in each control cycle, under the control error parameters allowed by the vehicle control system, the current driving distance estimated at the end of the current control cycle can be compared with the target driving distance to determine whether the current vehicle position has reached the expected position, that is, whether the current driving distance matches the target driving distance, and the current position control request can be terminated. It should be noted that this application does not limit the implementation method of this determination. For example, if the difference between the current driving distance and the target driving distance is less than the allowable control error distance, or the ratio between the current driving distance and the target driving distance is less than the allowable control error coefficient, etc., it can be determined that the current driving distance matches the target driving distance, meets the current vehicle driving control requirements, and the current position control request can be terminated.

[0046] Conversely, if the current driving distance is determined to be mismatched with the target driving distance, it indicates that the current vehicle position has not reached the desired position and continued vehicle control is required. In this case, the minimum stable speed control method will be used to control the vehicle's driving speed in the next control cycle to ensure smooth vehicle start-up or stability and safety during low-speed driving, while also improving driving comfort and the vehicle's dynamic response performance. To this end, the present application proposes dynamically adjusting the vehicle's drive motor torque in the next control cycle based on the current vehicle's actual driving conditions to achieve minimum stable speed control. This ensures that the vehicle's driving speed change in a specific driving mode is less than a speed change threshold (which can be the maximum speed fluctuation during system operation, often a very small value that is imperceptible to the driver and does not affect the vehicle's driving control accuracy. This application does not impose any restrictions on this value and may be determined based on the circumstances). The absolute value of the driving speed is also less than a speed threshold (which is generally the minimum speed at which the vehicle maintains stable driving under specific conditions. This application does not impose any restrictions on this value and may be determined based on the circumstances). This application does not impose any restrictions on how to control the drive motor torque to achieve minimum stable vehicle speed control, and according to actual needs, this application can also be combined with other methods (such as fuzzy control, motor speed control, motor running direction control, etc.) to achieve minimum stable vehicle speed control.

[0047] In one possible implementation, the driving motor torque expected to be executed in the next control cycle can be calculated using a speed control algorithm, such as based on the vehicle's current driving speed and the target driving speed in the specific driving mode. The target driving speed can be determined through calibration experiments and can be the minimum driving speed for stable and safe driving of the vehicle, in the expectation that the vehicle will reach and maintain the target driving speed in the next control cycle. The implementation process is not described in detail in this application.

[0048] In summary, in order to address the issue of inaccurate position estimation by the vehicle's position sensors, which can affect vehicle safety and stability and reduce passenger comfort, when an electric vehicle is in a specific driving mode, embodiments of the present application can initiate a position control request and input a target driving distance for the vehicle in the specific driving mode. During the vehicle controller's response to the position control request, no additional sensors are required. Instead, the vehicle controller directly utilizes the wheel speed sensors and rotation angle sensors already configured for each wheel to obtain the corresponding speed and rotation angle information for each wheel within the current control cycle. Based on this information, the current driving distance accumulated by the vehicle up to the current control cycle is accurately estimated. If it is determined that the current driving distance does not match the target driving distance, it is necessary to continue driving control for the next control cycle. In this case, the minimum stable vehicle speed control is achieved by adjusting the vehicle's drive motor torque in the next control cycle, ensuring that the vehicle in the specific driving mode can continue to travel safely and stably, while improving passenger comfort. In this manner, the vehicle position is gradually adjusted over multiple control cycles, better meeting the precise positioning requirements in scenarios such as autonomous driving, parking, or navigation.

[0049] Reference Figure 2 , is a flow chart of a vehicle driving control method proposed in the second embodiment of the present application. In order to improve control safety, the embodiment of the present application can first perform a rationality check on the input target driving distance before estimating the driving distance. Based on this, on the basis of the vehicle driving control method described in the above embodiment, as Figure 2 As shown, the vehicle driving control method proposed in this embodiment may further include the following steps:

[0050] Step S21, obtaining the attribute parameters of the wheel speed sensor corresponding to each wheel of the vehicle and the upper limit value of the driving distance calibrated for the vehicle;

[0051] In the embodiment of the present application, the upper limit of the driving distance is within the permissible error range of the target driving distance for controlling the vehicle's driving, and can be obtained by performing a calibration test on the vehicle. Since there is an estimation error in the driving distance estimation process, the estimation error will also accumulate and increase as the vehicle's driving displacement increases. In order to ensure that the cumulative estimation error does not exceed the maximum allowable estimation error, during the calibration test process, the vehicle driving control can be started from a smaller test driving distance, and the estimated error between the test driving distance and the actual driving distance is recorded; then the test driving distance is gradually increased to control the vehicle driving. Multiple tests can be performed for each test driving distance to determine the estimation error corresponding to the test driving distance until the obtained estimation error reaches the maximum allowable estimation error. The corresponding test driving distance is determined as the upper limit of the driving distance, that is, the maximum value of the target driving distance allowed to be input, such as 10m, etc. This application does not impose any restrictions on its value.

[0052] It should be understood that the upper limit of driving distance corresponding to vehicles with different configurations may be different, and can be configured to the vehicle controller or a memory connected to it after calibration testing before leaving the factory, so that after initiating a vehicle position control request, the vehicle controller can implement the rationality check of the target driving distance described in this embodiment based on this, but it is not limited to the configuration implementation method described in this embodiment.

[0053] In practical applications, the attributes of various speed sensors influence the detection accuracy of the corresponding wheel speed information, and thus the accuracy of travel distance estimation. This is particularly true of the minimum resolution of the wheel speed sensor, which refers to the smallest change in wheel speed that the wheel speed sensor can detect, and is referred to herein as the minimum travel distance unit. The smaller the wheel speed sensor's resolution, the more subtle changes it can detect, providing more accurate travel distance estimation. It should be understood that speed sensor attribute information may also include other attributes that influence wheel speed information detection accuracy, including but not limited to resolution. Furthermore, there are no restrictions on the configuration information that characterizes / defines the minimum resolution of a wheel speed sensor; it can be determined based on the wheel speed detection principle of the wheel speed sensor.

[0054] Step S22: determining a lower limit value of a travel distance of the vehicle based on the attribute parameters of the wheel speed sensor;

[0055] Following the above analysis, we take the Hall sensor as an example to illustrate the number of teeth K of the Hall sensor. n To determine its minimum resolution, when the wheel size of the vehicle (which can be represented by the radius R, but is not limited to this) is determined, the change of one tooth, that is, the minimum driving distance, can be determined as the lower limit of the driving distance, which can be expressed as: πR / K n It can be seen that in this embodiment, the lower limit of the driving distance of the corresponding vehicle can be determined based on the number of teeth of the Hall sensor and the wheel radius. The lower limit is usually the driving distance corresponding to a rising edge or falling edge of the Hall sensor output signal wave (Pulse Width Modulation Wave), such as 0.1m.

[0056] Because smaller Hall sensor resolution increases system complexity and power consumption, the lower limit of driving distance can be adaptively increased based on a comprehensive consideration of various factors. This application does not impose any numerical restrictions on the lower limit of driving distance. It should be understood that for other types of wheel speed sensors, the reference attribute is resolution or other attributes, and the lower limit of driving distance is directly determined based on this. Depending on the detection requirements, the lower limit of driving distance can be determined in combination with other parameters (which may be one or more parameters of the wheel speed sensor or the vehicle). This application does not provide detailed examples of this implementation process.

[0057] Step S23, determining whether the target driving distance is greater than or equal to the lower limit of the driving distance and less than or equal to the upper limit of the driving distance; if not, proceed to step S24; if yes, proceed to step S25;

[0058] In the embodiment of the present application, if the target driving distance is recorded as S d According to the method described above, the lower limit of the vehicle's driving distance is determined and recorded as S dl , the upper limit of the driving distance is recorded as S du , this application can obtain the target driving distance S d Then, directly determine the target driving distance S obtained this time according to the verification conditions expressed in the following formula d Is it reasonable?

[0059] ; (1)

[0060] Based on this, the target driving distance S input this time can be d and the lower limit of driving distance S dl , and the upper limit of driving distance S du Compare and determine whether the target driving distance meets the verification condition expressed by formula (1) to determine whether the target driving distance input this time is reasonable.

[0061] Step S24, continuing to control the vehicle operation according to the current drive motor torque and the current parking brake enable parameter of the vehicle, and ending the response to the position control request;

[0062] After the above judgment, it is determined that the target driving distance does not meet the verification condition expressed by formula (1), that is, it is determined that the target driving distance is less than the lower limit of the driving distance, or the target driving distance is greater than the upper limit of the driving distance, both of which indicate that the target driving distance is unreasonable. If the vehicle driving control is continued, the former verification result will lead to an inability to accurately estimate the driving distance, and the latter verification result will lead to an estimation error that is too large, reducing the control accuracy, and the algorithm will enter step S24 to end, such as executing the driving distance estimation algorithm in the vehicle driving control method proposed in the embodiment of the present application.

[0063] Based on this, and taking into account the safety of vehicle driving control, the vehicle's current driving motor torque and the current parking brake enable parameter (which indicates whether the vehicle's parking brake is currently being executed) can be left unchanged. That is, the vehicle's operation can be continued to be controlled based on the vehicle's current driving motor torque and the current parking brake enable parameter. In other words, without changing the vehicle's current control state, the position control request initiated for the vehicle is terminated, and the position control request is waited for to be initiated again. After the target driving distance is re-entered, the vehicle driving control method proposed in this application is executed.

[0064] In one possible implementation, the present application can output corresponding target driving distance prompt information based on the verification result that the target driving distance input this time is less than the lower limit of the driving distance, or the target driving distance is greater than the upper limit of the driving distance, so as to prompt the operator to input a reasonable target driving distance, such as how many meters the target driving distance should be increased / decreased at least, or output a target driving distance range consisting of the lower limit of the driving distance and the upper limit of the driving distance for the operator's reference to input a reasonable target driving distance, etc. The present application does not impose any restrictions on the content and output method of the target driving distance prompt information, which can be determined according to actual conditions, such as output through voice broadcast, display output on the vehicle terminal display screen, etc.

[0065] Among them, for the embodiment to determine the rationality verification result of the target driving distance, the corresponding rationality verification result can be represented by adjusting the status value of the position control status (which can be a flag bit, etc.), especially when the verification target driving distance is unreasonable, the status value of the position control status is adjusted to a status value indicating that the target driving distance is unreasonable, and it is displayed in the corresponding vehicle-mounted equipment, such as displaying the corresponding status value on the display screen, or controlling the indicator light indicating the position control status to adjust to the corresponding prompt color, or directly lighting up the indicator light indicating that the target driving distance is unreasonable, etc. This application does not limit the output method of each status value of the position control status, and can be flexibly configured according to actual conditions.

[0066] Step 25 : Obtain the current travel distance of the vehicle based on the stored rotation speed information and rotation angle information corresponding to each wheel of the vehicle.

[0067] After the above judgment, it is determined that the target driving distance meets the verification condition expressed by formula (1), that is, it is determined that the target driving distance is greater than or equal to the lower limit of the driving distance and less than or equal to the upper limit of the driving distance, which means that the target driving distance is reasonable and the driving distance estimation step can be continued. The estimation step can refer to the description of the corresponding part of the context embodiment, and this embodiment will not be described in detail here.

[0068] It can be seen that the embodiment of the present application can first determine whether the input target driving distance is reasonable before executing the vehicle driving distance estimation operation, effectively avoiding the input target driving distance being too large or too small, resulting in the estimated error accumulated over multiple control cycles exceeding the maximum allowable error value, thereby reducing the vehicle driving control safety and stability.

[0069] Reference Figure 3, is a flow chart of a vehicle driving control method proposed in the third embodiment of the present application. This embodiment proposes that before reading / storing the wheel speed information of each wheel in the current control cycle, the corresponding wheel speed sensor can be checked for faults to ensure that the speed information used to estimate the driving distance is reliable, thereby improving control reliability. Based on this, on the basis of the vehicle driving control method described in the above embodiment, Figure 3 As shown, the vehicle driving control method proposed in this embodiment may also include but is not limited to the following steps:

[0070] Step S31, performing fault detection on the wheel speed sensor corresponding to each wheel of the vehicle;

[0071] Step S32: If the wheel speed sensors corresponding to at least the wheels on the same side of the vehicle are all in a faulty state, then the response to the vehicle position control request is terminated.

[0072] During actual vehicle driving, if the wheel speed sensors corresponding to all wheels on the same side malfunction, accurate wheel speed information for each wheel on that side cannot be obtained. This incorrect wheel speed information for each wheel on that side will lead to inaccurate estimates of the distance traveled for those wheels. Consequently, the combined estimated distance traveled for all wheels will result in an inaccurate total vehicle distance traveled. However, if the wheel speed information for only one wheel on that side is inaccurate or missing, the total vehicle distance traveled can still be calculated using the rotation angle information of that wheel, the speed and rotation angle information of other wheels, the positional relationship between the wheels, the wheel radius, and the properties of the wheel speed sensors, and mathematical operations.

[0073] Therefore, the present application can determine whether the wheel speed sensors corresponding to at least the wheels on the same side of the vehicle are all in a faulty state. If the stored wheel speed information of the wheels on the first side of the vehicle is inaccurate or missing, or the wheel speed sensors corresponding to the wheels on the first side of the vehicle and some / all of the wheels on the second side of the vehicle are all in a faulty state, it is considered that the wheel speed sensors deployed on the vehicle are completely faulty and the vehicle driving control can no longer be achieved based on them. In this case, the operation after determining that the obtained target driving distance is unreasonable as in the above embodiment can be performed, that is, the vehicle controller will not output control of the current drive motor torque and the current parking brake enable parameter, and the algorithm ends, that is, the response to the position control request initiated this time ends. After determining that the wheel speed sensor in the faulty state has switched to the valid state, the operator can be prompted to re-initiate the position control request for the vehicle.

[0074] Step S33: If the wheel speed sensors corresponding to at least three wheels of the vehicle are in a valid state, the wheel speed information corresponding to each wheel speed sensor in a valid state generated in the current control cycle and the steering angle information of the corresponding wheel are read to obtain the current travel distance of the vehicle.

[0075] Following the above analysis, with respect to the fault detection results of each wheel speed sensor, if it is determined that there is no wheel speed sensor corresponding to a wheel on the same side that is in a faulty state, such as for a vehicle with four wheels, or two vehicles on the same side, if the wheel speed sensors corresponding to at least three wheels are in a valid state, the vehicle's travel distance can still be estimated. In this case, the travel distance estimation step of step S12 can be executed for each wheel whose wheel speed sensor is in a valid state, that is, the current travel distance of the vehicle is obtained based on the stored wheel speed information corresponding to each wheel speed sensor in a valid state generated during the current control cycle, as well as the steering angle information of the corresponding wheel. The implementation process will not be described in detail in this application.

[0076] In one possible implementation, during the operation of the vehicle control system, each wheel speed sensor may automatically report its operating status, or the vehicle controller may determine whether the corresponding wheel speed sensor is faulty based on the communication between the wheel speed sensor and the vehicle controller. Alternatively, a fault detection device may perform fault detection on each wheel speed sensor. Alternatively, the vehicle controller may obtain the operating parameters of each wheel speed sensor and perform fault diagnosis on the corresponding wheel speed sensor using an appropriate fault diagnosis algorithm. This application does not limit the fault detection method for each wheel sensor. Subsequently, based on the fault detection result, the status value of the fault flag of the corresponding wheel speed sensor may be configured so that the status value of the fault flag can be read later to directly determine whether the corresponding wheel speed sensor is faulty.

[0077] Thus, during the aforementioned process of detecting faults in each wheel speed sensor, the fault flag of the wheel speed sensor corresponding to each wheel of the vehicle can be read. If the fault flag of any wheel speed sensor is at a first state value, the wheel speed sensor is determined to be in a faulty state; if the fault flag of any wheel speed sensor is at a second state value, the wheel speed sensor is determined to be in a valid state. Based on this, it is possible to quickly and accurately determine whether the wheel speed sensor corresponding to each wheel of the vehicle is faulty, and then proceed according to the method described in step S32 or step S33.

[0078] It should be understood that, during the fault detection process of each wheel sensor, if it is determined that any wheel speed sensor has switched from a faulty state to a valid state, the fault flag of the wheel speed sensor can be promptly updated to the second state value; similarly, if it is determined that any wheel speed sensor has switched from a valid state to a faulty state, the fault flag of the wheel speed sensor can be promptly updated to the first state value to ensure the reliability of subsequent operations performed based on the fault flag.

[0079] For example, a vehicle includes four wheels, namely the left front wheel, the left rear wheel, the right front wheel, and the right rear wheel. The fault flags of the corresponding wheel speed sensors (such as Hall sensors) can be recorded as follows: N dl1 、N dl2 、N dr1 、N dr2 According to the wheel speed sensor fault detection and processing method described above, after reading the status value of the fault flag bit of each wheel speed sensor, if the fault judgment condition expressed by the following formula is met, each wheel speed sensor is considered to be completely faulty and the response to the position control request initiated this time is terminated; otherwise, the driving distance estimation can continue.

[0080] ; (2)

[0081] In formula (2), ∧ is a conjunction symbol, which indicates an “and” (that is, “and”) relationship, and both the relational expressions on both sides of ∧ must be satisfied; ∨ is a disjunction symbol, which indicates an “or” relationship, and any one of the relational expressions in the brackets on both sides of ∨ must be satisfied.

[0082] Therefore, when the first state value is 0 and the second state value is 1, This means that the wheel speed sensors corresponding to the two wheels on the right side of the vehicle are in a faulty state. This means that the wheel speed sensors corresponding to the two wheels on the left side of the vehicle are both in a faulty state. , or satisfy If one or two of the sub-conditions are satisfied, formula (2) is satisfied, and step S32 is executed; otherwise, if , that is, the wheel speed sensors corresponding to the three wheels are in a valid state, or , that is, the wheel speed sensors corresponding to all wheels are in a valid state, it can be assumed that the wheel speed sensors corresponding to each wheel are not completely faulty, and step S33 can be continued to estimate the traveled distance. It should be understood that for vehicles with a larger number of wheels, the implementation method of wheel speed sensor fault detection is similar, and this application does not provide detailed examples one by one.

[0083] In summary, in the present application, when responding to a position control request for the vehicle, before executing distance estimation, the method described above can be used to detect whether the wheel speed sensor (such as a Hall effect sensor) corresponding to each wheel is faulty. This can determine whether the subsequent distance estimation step can be continued. This avoids the situation where the distance estimation step is continued even if each wheel speed sensor is considered to be completely faulty. This would result in inaccurate or missing speed information being read, making it impossible to accurately estimate the current distance traveled by the vehicle, thereby affecting the safety and stability of the vehicle's driving control. If it is determined that each wheel speed sensor is not completely faulty, the subsequent distance estimation step can be allowed to proceed, thereby ensuring the safety and stability of vehicle driving control.

[0084] In some embodiments, the vehicle driving control method proposed in Example 1 can be optimized by combining the aforementioned Example 2 and Example 3. Specifically, the vehicle driving distance can be estimated after determining that the target driving distance obtained this time is reasonable and that the wheel speed sensors corresponding to each wheel are not completely faulty (i.e., the wheel speed sensors on the same wheel do not fail simultaneously, as described in step S33). Otherwise, the driving distance estimation algorithm can be terminated directly, and no further response to the current position control request can be made. It should be noted that, to improve vehicle control reliability and safety, other verifications can be combined as needed, but this implementation process is not described in detail in this application.

[0085] In one possible implementation, taking the scenario where the wheel speed sensor is a Hall sensor as an example to illustrate the driving distance estimation process, the stored speed information and angle information corresponding to each wheel of the vehicle generated during the current control cycle can be read. Based on the speed information, angle information, rolling radius and number of Hall sensor teeth corresponding to each wheel, the wheel driving distance of the corresponding wheel during the current control cycle can be determined. Therefore, based on the driving distance of each wheel and the driving distance obtained by the vehicle in the previous control cycle, the current driving distance of the vehicle, that is, the driving distance accumulated to the end time of the current control cycle, is obtained.

[0086] As can be seen, compared to directly measuring the distance traveled by the entire vehicle, this application takes into account the differences in speed and angle information of different wheels during vehicle travel, thereby improving the accuracy of vehicle distance estimation. It should be noted that the wheel speed information of each wheel includes, but is not limited to, the changes in the output signal wave of the Hall effect sensor. Other types of wheel speed sensors can also be used as needed to calculate the distance traveled by each wheel using appropriate mathematical formulas in combination with their detection principles. This implementation process is not detailed in this application.

[0087] Reference Figure 4, a flowchart of a vehicle driving control method proposed in the fourth embodiment of the present application, in the vehicle driving control method implemented in each of the above embodiments or combinations, this embodiment can provide a detailed description of an optional implementation method for how to achieve driving distance estimation. Combined with the above analysis, this application takes the scenario where the wheel speed sensor is a Hall sensor as an example to illustrate the driving distance estimation process. Figure 4 As shown, the method may include:

[0088] Step S41, respectively obtaining the number of rising edges and falling edges of the Hall sensor output signal wave of each wheel of the vehicle generated in the current control cycle, and the rotation angle information collected by the rotation angle sensor of each wheel;

[0089] In this embodiment of the present application, if it is determined that the vehicle's current travel distance can be estimated, such as if the target travel distance is verified to be reasonable and the wheel speed sensors are not completely faulty, and if the Hall effect sensors corresponding to each wheel are operating normally (i.e., all are in an active state), the corresponding cached speed information can be read. That is, the stored speed information corresponding to each wheel of the vehicle generated during the current control cycle can be read. Simultaneously, the rotation angle information corresponding to each wheel can also be read. If one wheel speed sensor is faulty, the speed information and rotation angle information corresponding to the wheel corresponding to each active wheel speed sensor are read.

[0090] It should be noted that the end time of the current control cycle is the current reading time. For example, if the control cycle is 10ms, distance estimation and position control are performed every 10ms. From 0 to 10ms, the wheel speed and steering angle information of each wheel are synchronously detected and stored. To facilitate subsequent reading, the corresponding timestamp (such as the detection time) can be recorded. In this way, when the time from the start time of the position control request response reaches 10ms, the wheel speed and steering angle information of each wheel within 10ms can be read, and the vehicle's distance traveled in this 10ms can be estimated. From 10ms to 20ms, the wheel speed and steering angle information of each wheel in this time period can still be stored in this manner. When 20ms is reached, the current distance traveled by the vehicle up to 20ms can be estimated. This is the accumulated distance traveled from 0ms to 20ms, which is also the sum of the actual distances traveled during these two control cycles. This periodic control cycle is repeated until the accumulated current distance matches the target distance input for this time.

[0091] In one possible implementation, in a scenario where the wheel speed information of the corresponding wheel is determined based on the change in the output signal wave of the Hall sensor, during the wheel speed information detection process of each wheel, the number of rising edges and the number of falling edges generated by the Hall sensor output signal wave corresponding to each wheel of the vehicle in the current control cycle can be obtained respectively, and the rotational speed of the corresponding wheel is represented by the number of rising edges and the number of falling edges. Thereafter, the rotational speed information of the corresponding wheel is constituted by the number of rising edges and the number of falling edges generated by the same Hall sensor output signal wave in the current control cycle.

[0092] Still taking the vehicle as an example with four wheels, namely the left front wheel, the left rear wheel, the right front wheel, and the right rear wheel, the number of rising edges of each wheel can be recorded as: N r =[ N rl1 N rl2 N rr1 N rr2 ], the number of falling edges of each wheel can be recorded as: N f =[ N fl1 N fl2 N fr1 N fr2 ]. In this way, the application can record the number of rising edges N of the Hall sensor output signal wave (such as PWM wave) corresponding to the left front wheel, left rear wheel, right front wheel, and right rear wheel detected in each control cycle. r and the number of falling edges N f , this application is for the number of rising edges N r and the number of falling edges N f The detection implementation method is not described in detail.

[0093] Similarly, the steering angle information of the corresponding wheel can be obtained based on the output signal of the steering angle sensor of each wheel, which can be expressed as θ=[θ l1 θ l2 θ r1 θ r2 ], θ l1 ,θ l2 ,θ r1 ,θ r2 The left front wheel, the left rear wheel, the right front wheel, and the right rear wheel respectively represent the steering angle information corresponding to each of the wheels. The steering angle information is a steering angle vector and the unit can be: ° (degree).

[0094] Step S42, determining the rolling radius and the number of Hall sensor teeth corresponding to each wheel of the vehicle;

[0095] Step S43, determining a wheel travel distance of each wheel in the current control cycle based on the rotation angle information of each wheel, the number of rising edges and falling edges of the corresponding Hall sensor output signal wave generated in the current control cycle, the rolling radius of the wheel, and the number of Hall sensor teeth;

[0096] In this embodiment of the present application, the wheel distance traveled by each wheel within the current control cycle can be determined based on the corresponding wheel's speed information, rotation angle information, rolling radius, and number of Hall sensor teeth, and the vehicle's total distance traveled can then be estimated. Therefore, when estimating the distance traveled by a single wheel, combined with the above description of distance estimation based on Hall sensor output signals, differences in wheel radius, speed, rotation angle, or one or more of these information for different wheels during the same time period can result in different estimated distances.

[0097] Therefore, in the process of estimating the wheel travel distance of each wheel in the current control cycle, the rolling radius of the corresponding wheel (i.e., the wheel radius R mentioned above) can be obtained. The unit can be m, which is usually determined by the tire model used for the wheel. In the scenario where the wheel speed information is determined based on the output signal wave change of the Hall sensor, the number of Hall sensor teeth corresponding to each wheel (i.e., the number of gears K mentioned above) can be obtained. n ), which can be determined by the type of Hall sensor. These can be recorded as vehicle constant parameters in the storage device of the vehicle control system so that they can be directly read when needed. Afterwards, the wheel speed of each wheel (such as the above N r 、N f ), the minimum driving distance of each gear of the Hall sensor is calculated by mathematical operation to obtain the accumulated driving distance of the corresponding wheel in the current control cycle.

[0098] In a possible implementation, it is assumed that the wheel travel distances corresponding to the left front wheel, left rear wheel, right front wheel, and right rear wheel of the vehicle are expressed as follows: S l1 、S l2 、S r1 、S r2 , can be calculated according to the following formula:

[0099] ; (3)

[0100] ; (4)

[0101] ; (5)

[0102] ; (6)

[0103] Combined with the meaning of each letter in the formula above, the wheel distance traveled by each wheel in the current control cycle is calculated according to each formula. It should be noted that when other types of wheel speed sensors are used to detect the wheel speed information of the corresponding wheels, the corresponding calculation method can be combined with the detection principle and the relationship between wheel speeds to calculate the wheel distance traveled by the corresponding wheel in the current control cycle based on the rotational speed information and rotation angle information of each wheel, as well as appropriate vehicle constant parameters. This implementation process is not described in detail in this application.

[0104] Step S44, performing a mean calculation on the travel distances of the various wheels in the current control cycle to obtain an average travel distance of the wheels of the vehicle in the current control cycle;

[0105] Step S45 , summing the average travel distance of the wheel and the travel distance of the vehicle in the previous control cycle to obtain the current travel distance of the vehicle.

[0106] In the actual application of this application, in one possible implementation, such as the implementation described in steps S44 and S45, the current travel distance of the entire vehicle can be estimated by averaging the travel distances of each wheel. Following the above analysis, the current travel distance can be expressed as:

[0107] ; (7)

[0108] In formula (7), S on the right side of the equal sign is x Indicates the current driving distance of the vehicle obtained in the previous control cycle (i.e., the previous historical control cycle adjacent to the current control cycle). S on the left side of the equal sign x represents the current driving distance of the vehicle obtained in the current control cycle. It can be seen that the current driving distance obtained in each control cycle is a cumulative value. It should be noted that if the Hall sensor of a wheel fails, the speed and angle information of that wheel are not included in the calculation, and the wheel driving distance of that wheel is not calculated. In formula (7), the wheel driving distance of that wheel is not included in the distance, for example, the status value of its fault flag is configured to 0.

[0109] To summarize, in the embodiments of the present application, the rotation speed information of the corresponding wheel is accurately measured by detecting the number of rising edges and falling edges of the Hall sensor output signal wave corresponding to each wheel, and the rotation angle information of the corresponding wheel is detected in real time through the rotation angle sensor of each wheel. In this way, when initiating a vehicle position control request and controlling the vehicle in a specific driving mode to safely and smoothly drive the desired target driving distance, the number of rising edges, the number of falling edges, the rotation angle information, the rolling radius of the wheel and the number of Hall sensor teeth corresponding to each wheel can be used to accurately calculate the wheel driving distance of the corresponding wheel itself in the current control cycle. Thereafter, the vehicle driving distance in the current control cycle can be accurately obtained by using the mean calculation method, thereby ensuring the reliability and accuracy of the current driving distance accumulated thereby.

[0110] Combining the driving distance estimation methods described in the various embodiments above, after each accumulation to obtain the current driving distance of the vehicle at the end of the current control cycle, it is possible to determine whether the current driving distance matches the target driving distance. In combination with the description of the corresponding part of the first embodiment above, it is possible to combine the allowable driving distance error coefficient (which is usually a value from 0 to 1, that is, the value range is [0,1], and its value can be determined by calibration experiments, such as starting from 1 and gradually decreasing, testing the corresponding driving distance estimation error, and selecting the value corresponding to the minimum error as the driving distance error coefficient, such as 0.99, etc., and this application does not impose any restrictions on its value) to determine whether the current driving distance reaches the desired target driving distance. Assume that the driving distance error coefficient is expressed as K x 、The current driving distance is S x 、The target driving distance is S d If the parking condition expressed by the following formula is met, the vehicle can stop directly, ending the current position control request, that is, ending the driving distance estimation algorithm:

[0111] ; (8)

[0112] As can be seen, if the current driving distance multiplied by the driving distance error coefficient is less than the target driving distance, the stopping condition is not yet met and driving control can still be executed in the next control cycle. This can be achieved by using the minimum stable vehicle speed control method. Conversely, if the multiplied driving distance is greater than or equal to the target driving distance, the position has reached the expected driving distance and the stopping condition is met. Typically, when the driving distance equals the target driving distance, the vehicle stops and the algorithm ends.

[0113] According to the method described above, if the current driving distance is determined to be inconsistent with the target driving distance, that is, if formula (8) is satisfied, it is necessary to enter the next control cycle to continue the vehicle driving control; if the current driving distance is determined to be consistent with the target driving distance, the parking brake enable parameter of the vehicle can be controlled to be at the first parameter (such as 1), indicating that the parking brake operation is performed on the vehicle, and the target drive motor torque of the vehicle is controlled to be zero (if the drive motor torque is represented by T d , can control T d = 0, discontinuing the motor drive), and setting the vehicle's position control state to a value indicating completion of control for the target driving distance. Thus, by estimating driving distance over several control cycles and controlling the drive motor torque and parking brake, it is possible to precisely control vehicle driving distance in specific driving modes, such as low-speed driving mode or starting mode, ensuring vehicle driving safety and stability and meeting the driving requirements of the specific driving mode.

[0114] In one possible implementation, when the current driving distance does not match the target driving distance, a speed control algorithm can be used to dynamically adjust the drive motor torque to achieve minimum stable vehicle speed control in the next control cycle, that is, to ensure that the vehicle's driving speed change in a specific driving mode is less than the speed change threshold, that is, the vehicle can travel at a stable speed, thereby improving the safety and stability of the vehicle's driving in this mode, ensuring the comfort of passengers, and better meeting the control requirements in scenarios such as automatic parking.

[0115] Optionally, the speed control algorithm can be an integral control algorithm. Thus, when the vehicle is in low-speed driving mode, integral control can be used to determine the target drive motor torque, and this target drive motor torque can be used as the total drive torque to control vehicle operation. In one possible implementation, the target drive motor torque can be calculated using a PID (Proportional-Integral-Derivative) algorithm as shown in the following formula:

[0116] ; (9)

[0117] In formula (9), K p , K i , K d represents the proportional control coefficient, integral control coefficient and differential control coefficient respectively, which can be determined by calibration experiments. It should be understood that since K p The larger the parameter, the faster the response time, but it is prone to overshoot; K i The larger the value, the smaller the speed control error, but it is also prone to overshoot; K d Is to increase the response speed, K d The larger the Kp It can be increased accordingly, but the impact on noise will be greater. This application can reasonably determine the various control coefficients of the test during the calibration test according to this change relationship. V represents the actual speed of the vehicle, that is, the current driving speed, v d It can represent the target driving speed of the vehicle in a specific driving mode, which can be the minimum stable speed that meets the minimum stable speed control. It can be determined through calibration experiments and is usually a small value. It can be expressed as (v d -v) difference.

[0118] In another possible implementation, the present application may also adopt a feedforward plus feedback method to calculate the target drive motor torque, and the formula is as follows:

[0119] ; (10)

[0120] In formula (10), T i The feedforward torque can be expressed using T i = (MgRsinα) / k, where M represents the mass of the entire vehicle, R represents the rolling radius of the wheel, k represents the motor reduction ratio, and α represents the slope, which can be acquired by sensors or calculated using a slope estimation algorithm. The meanings of the other letters in formula (10) are consistent with those of the same letters in formula (9) and are not detailed in this application.

[0121] It should be noted that the calculation method of the vehicle's drive motor torque includes but is not limited to the two methods exemplified above. You can choose a suitable formula for calculation according to the specific application scenario and requirements. This application does not give detailed examples one by one. c Can be used as the target driving motor torque T d After the output, that is, T d =T c , and controls the parking brake enabling parameter to be at the second parameter (such as 0), controlling the vehicle to run safely and smoothly.

[0122] If the vehicle is a multi-motor vehicle, the driving motor torque T in this application is d Refers to the total torque of all the vehicle's drive motors. If the vehicle is a single-motor model, the calculated T c Is the only driving motor torque. In addition, when the vehicle controller is of different types, after the target driving motor torque is output, the corresponding control logic can be used to control the vehicle operation. d Send it directly to the vehicle controller for execution; if the vehicle controller is a motor controller or an all-in-one controller, T dAfter conversion into corresponding current, the vehicle operation is controlled according to the current. This application does not elaborate on the implementation process of how to control the vehicle operation based on the driving motor torque.

[0123] In summary, the vehicle driving control method described in each embodiment above can be applied to the method according to Figure 5 The signal interface diagram shown is configured for the various input signals and output signals of the vehicle driving control method proposed in this application. The input signals for implementing the method may include the number of rising edges N of the Hall sensor output signals corresponding to the left front wheel, left rear wheel, right front wheel, and right rear wheel of the vehicle. r , Number of falling edges N f And the fault flag N d (For example, the state value 0 indicates a fault state, and the state value 1 indicates a valid state), the angle information θ detected by the corresponding angle sensor of each wheel, the position control request S of the vehicle is initiated f (i.e., the position control flag indicating whether a vehicle control request is initiated, 0 indicates not to start / end, 1 indicates to start), target driving distance S d , these input signals are sent to the vehicle controller to execute the vehicle driving control method proposed in this application.

[0124] The vehicle controller executes the above method and can output the driving motor torque T d , parking brake enable parameter P d (0 means no parking brake, 1 means parking brake, stop), and the position control status can also be output as needed, that is, the flag C indicating whether the position control request for the target driving distance is completed. d , such as the status value indicating that no position control request has been initiated (C d =0), indicating the status value in the position control request response (C d =1), indicating that the control for the target driving distance is completed (C d =2), a status value indicating that the response to the position control request is terminated due to a fault in the Hall sensor (C d =3, and a status value indicating that the target driving distance is unreasonable (C d =4) one or more.

[0125] Combine Figure 5 As shown in the signal interface diagram, preferably, the present application can combine the vehicle driving control methods described in the above embodiments to obtain the following Figure 6 The flow chart of the vehicle driving control method shown in FIG. 1 shows that in the initialization phase, the position control flag is S while waiting for the position control request in the manner described above. f=0, initiate a position control request, and update the position control flag to 1, that is, S f =1, then the current driving distance of the vehicle is initialized to zero, that is, S x =0, the vehicle controller can read the position control flag bit. If S f =0, output C d =0, incorrect T d and P d Perform output control and continue to wait for position control request.

[0126] If the position control flag read by the vehicle controller is 1, that is, S f =1, the input target driving distance S d Perform rationality check, if it is unreasonable, you can output C d =4, indicating that the target driving distance entered this time is unreasonable, and T is not changed. d and P d The current state value of the position control request ends and the S f Update from 1 to 0 and continue waiting for the next position control request.

[0127] If the target driving distance S is determined d Reasonable, you can further check whether the Hall sensor of each vehicle is faulty, according to the fault flag status value N corresponding to the left front wheel, left rear wheel, right front wheel and right rear wheel of the vehicle d , determine whether to continue to perform the subsequent control steps, according to the fault detection method described in the corresponding embodiment above, if it is determined that each Hall sensor is not completely faulty, the driving distance estimation can continue; otherwise, output C d =3, which indicates that the fault detection result of the Hall sensor failure is still not necessary. d and P d Perform output control, end the algorithm, and set S f Update from 1 to 0 and continue waiting for the next position control request.

[0128] The current driving distance S of the vehicle is obtained by estimating the cumulative value. x After that, the parking judgment condition shown in formula (8) can be used to determine whether to park. If it is satisfied, it means that the control is not completed. The vehicle is controlled to the minimum stable speed, the target drive motor torque Tc is calculated, and C is output. d =1, indicating that during the current position control request response process, the output drive motor torque is the target drive motor torque, that is, T d =Tc, the parking brake enable parameter is 0, that is, P d=0, no parking brake, control the vehicle to run smoothly in the next control cycle. If the parking judgment condition is met, it means that the position control request is completed and the output drive motor torque can be 0, that is, T d =0, the parking brake enable parameter is 1, that is, P d =1, apply parking brake and stop control.

[0129] The above describes a vehicle driving control method provided by an embodiment of the present application. The following describes a device for executing the above vehicle driving control method.

[0130] Reference Figure 7 , is a schematic diagram of the structure of the vehicle driving control device proposed in the embodiment of the present application, such as Figure 7 As shown, the device may include:

[0131] a target driving distance acquisition module 71 for acquiring a target driving distance of the vehicle in response to a position control request for a vehicle in a specific driving mode; the specific driving mode includes a low-speed driving mode and a starting mode;

[0132] a current travel distance acquisition module 72 for acquiring the current travel distance of the vehicle based on the rotational speed information and rotation angle information corresponding to each wheel of the vehicle; the rotational speed information is obtained based on the output change of the wheel speed sensor of the corresponding wheel during the current control cycle;

[0133] The drive motor torque adjustment module 73 is used to determine that the current driving distance does not match the target driving distance, and to control the vehicle's driving motor torque in the next control cycle to ensure that the change in the vehicle's driving speed in the specific driving mode is less than a vehicle speed change threshold, and the absolute value of the driving speed is less than a vehicle speed threshold.

[0134] In some embodiments, the vehicle driving control device may further include:

[0135] a first acquisition module, configured to acquire attribute parameters of the wheel speed sensor and an upper limit value of a target distance calibrated for the vehicle; wherein the upper limit value of the target distance is within an allowable error range of a target travel distance for controlling the vehicle;

[0136] a first determining module, configured to determine a lower limit value of a target distance for the vehicle based on attribute parameters of the wheel speed sensor;

[0137] a first control module, configured to determine whether the target driving distance is less than the target distance lower limit or greater than the target distance upper limit, continue controlling the vehicle operation based on a current drive motor torque and a current parking brake enable parameter of the vehicle, and terminate responding to the position control request;

[0138] The second determination module is used to determine that the target driving distance is greater than or equal to the lower limit of the target distance and less than or equal to the upper limit of the target distance, triggering the current driving distance acquisition module 72 to execute the step of acquiring the current driving distance of the vehicle based on the stored speed information and angle information corresponding to each wheel of the vehicle.

[0139] In some embodiments, the vehicle driving control device may further include:

[0140] a fault detection module, configured to perform fault detection on the wheel speed sensor corresponding to each wheel of the vehicle;

[0141] a second control module, configured to terminate the response to the position control request if the wheel speed sensors corresponding to at least the wheels on the same side of the vehicle are all in a fault state;

[0142] The third determination module is used to trigger the current travel distance acquisition module 72 to execute the step of acquiring the current travel distance of the vehicle based on the stored rotation speed information and rotation angle information corresponding to each wheel of the vehicle if the wheel speed sensors corresponding to at least three wheels of the vehicle are in a valid state.

[0143] In a possible implementation, if the wheel speed sensor is a Hall sensor, the current travel distance acquisition module 72 may include:

[0144] A first reading unit is configured to read the stored rotation speed information and rotation angle information corresponding to each wheel of the vehicle generated during a current control cycle; the end time of the current control cycle is the current reading time;

[0145] a wheel travel distance determination unit, configured to determine the wheel travel distance of the corresponding wheel in the current control cycle based on the rotation speed information, the rotation angle information, the rolling radius, and the number of Hall sensor teeth corresponding to each wheel;

[0146] The first acquisition unit is configured to acquire the current driving distance of the vehicle based on the driving distance of each wheel and the driving distance obtained by the vehicle in the previous control cycle.

[0147] In some embodiments, the speed information acquiring unit for obtaining the speed information of the corresponding wheel based on the output change of the wheel speed sensor of the wheel in the current control cycle may include:

[0148] a second acquiring unit, configured to respectively acquire the number of rising edges and the number of falling edges of the output signal wave of the Hall sensor of each wheel of the vehicle generated in a current control cycle;

[0149] The number of rising edges and the number of falling edges represent the rotational speed of the corresponding wheel;

[0150] The number of rising edges and the number of falling edges generated by the same Hall sensor output signal wave in the current control cycle constitute the speed information of the corresponding wheel.

[0151] Those skilled in the art will understand that the functions and technical effects of each module in the above-mentioned device embodiment, as well as the units for implementing the functions, are equivalent to the corresponding steps described in the above-mentioned method embodiment. For specific implementation details, please refer to the description of the method part, and the device embodiment does not elaborate on them one by one.

[0152] An embodiment of the present application also provides a computer program product including computer-readable instructions. When the computer-readable instructions are executed on a vehicle controller, the vehicle controller implements any variable angle transmission ratio control method provided in the embodiment of the present application.

[0153] A computer-readable storage medium is also provided in an embodiment of the present application. The storage medium carries one or more computer programs. When one or more computer programs are executed by an electronic device, the vehicle controller / on-board terminal can implement any vehicle driving control method provided in an embodiment of the present application.

[0154] The computer-readable storage medium can be any available medium capable of storing data on a computer, or a data storage device such as a training device or data center that includes one or more available media. Available media can include magnetic media (e.g., floppy disks, hard disks, or magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives (SSDs)).

[0155] Reference Figure 8 , is a structural diagram of an optional embodiment of a vehicle controller applicable to the vehicle driving control method proposed in this application, wherein the vehicle controller is configured in a vehicle, such as Figure 8 As shown, the vehicle controller may include at least one memory 810 and at least one processor 820, and the at least one memory 810 and the at least one processor 820 may communicate via a bus 830. The bus 830 may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 8 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0156] The memory 810 is used to store multiple computer instructions, which are loaded and executed by the processor 820 to implement the various steps of the vehicle driving control method proposed in the embodiment of the present application. It can also call other components in the vehicle (such as sensors or steering mechanisms, etc.) to implement corresponding functions. The implementation process can refer to the description of the corresponding part of the method embodiment above.

[0157] In the embodiment of the present application, the memory 810 includes at least one volatile memory (volatile memory), and may also include at least one non-volatile memory (non-volatile memory) and other storage media. The processor 820 may include any one or more of a central processing unit (CPU), a graphics processing unit (GPU), a microprocessor (MP), a digital signal processor (DSP), an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA). The present application does not limit the types of the memory 810 and the processor 820 and their working principles, and they can be flexibly configured according to actual needs.

[0158] In practical applications, the memory 810 can be used to store computer instructions and data, and can include an instruction storage area and a data storage area. The data storage area can store various data, such as the speed information and the angle information corresponding to each wheel detected by each sensor, and Figure 5 The memory 810 can store input and output signals, as well as intermediate data generated during vehicle driving control. The instruction storage area can store software units such as an operating system, applications, and computer instructions required for at least one function. As analyzed above, the memory 810 can provide the processor 820 with multiple computer instructions for implementing the vehicle driving control method according to the embodiment of the present application, as well as data or other software and hardware resources required during the execution of the vehicle driving control method.

[0159] It should be understood that Figure 8 The structure of the vehicle controller shown does not constitute a limitation on the vehicle controller in the embodiment of the present application. In actual applications, the vehicle controller may include Figure 8 More components shown, or combinations of certain components, etc., are not listed one by one in this application.

[0160] The present application also provides a vehicle that may include a vehicle controller as described in the above embodiments. The vehicle may be any type of electric vehicle, such as a personal car, bus, truck, or new energy vehicle (such as a hybrid vehicle or a pure electric vehicle). The vehicle can use its configured vehicle controller to execute the vehicle driving control method proposed in the present application embodiment to solve the problem of inaccurate driving position estimation under low-speed driving conditions, which leads to the inability to perform precise position control. Without the need for additional configuration components, the method uses the changes in the Hall sensor output signal waves corresponding to each wheel, combined with the vehicle's constant parameters, to accurately estimate the vehicle's driving distance. By controlling the drive motor torque and the parking brake, the vehicle's safe and stable driving distance control is achieved, thereby improving the driving experience.

[0161] In addition, it should be noted that the device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed across multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment. In addition, in the drawings of the device embodiments provided in this application, the connection relationship between the modules indicates that there is a communication connection between them, which can be specifically implemented as one or more communication buses or signal lines.

[0162] Through the description of the above embodiments, in the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part.

Claims

1. A vehicle driving control method, characterized in that: The vehicle driving control method comprises: In response to a position control request for a vehicle in a specific driving mode, obtaining a target driving distance of the vehicle; the specific driving mode includes a low-speed driving mode and a starting mode; Obtaining a current travel distance of the vehicle based on speed information and rotation angle information corresponding to each wheel of the vehicle; the speed information is obtained based on output changes of wheel speed sensors of corresponding wheels within a current control cycle; It is determined that the current driving distance does not match the target driving distance, and by adjusting the driving motor torque of the vehicle in the next control cycle, the driving speed change of the vehicle in the specific driving mode is controlled to be less than a vehicle speed change threshold, and the absolute value of the driving speed is less than a vehicle speed threshold.

2. The vehicle driving control method according to claim 1, characterized in that: The vehicle driving control method further includes: Acquiring attribute parameters of the wheel speed sensor and a target distance upper limit value calibrated for the vehicle; wherein the target distance upper limit value is within an allowable error range of a target travel distance for controlling travel of the vehicle; determining a lower limit value of a target distance for the vehicle based on attribute parameters of the wheel speed sensor; determining that the target driving distance is less than the target distance lower limit or greater than the target distance upper limit, continuing to control the vehicle operation based on the current drive motor torque of the vehicle and the current parking brake enable parameter, and ending the response to the position control request; Determine that the target driving distance is greater than or equal to the target distance lower limit and less than or equal to the target distance upper limit, and execute the step of obtaining the current driving distance of the vehicle based on the speed information and the turning angle information corresponding to each wheel of the vehicle.

3. The vehicle driving control method according to claim 1, characterized in that: The vehicle driving control method further includes: Performing fault detection on the wheel speed sensor corresponding to each wheel of the vehicle; If the wheel speed sensors corresponding to at least the wheels on the same side of the vehicle are both in a fault state, ending the response to the position control request; If the wheel speed sensors corresponding to at least three wheels of the vehicle are in a valid state, for each wheel whose wheel speed sensor is in the valid state, execute the step of obtaining the current travel distance of the vehicle based on the rotation speed information and rotation angle information corresponding to each wheel of the vehicle.

4. The vehicle driving control method according to any one of claims 1 to 3, characterized in that: If the wheel speed sensor is a Hall sensor, obtaining the current travel distance of the vehicle based on the rotation speed information and the rotation angle information corresponding to each wheel of the vehicle includes: Reading the stored rotation speed information and rotation angle information corresponding to each wheel of the vehicle generated in the current control cycle; the end time of the current control cycle is the current reading time; Determining a wheel travel distance of the corresponding wheel in the current control cycle according to the rotation speed information, the rotation angle information, the rolling radius, and the number of Hall sensor teeth corresponding to each wheel; The current driving distance of the vehicle is obtained according to the driving distance of each wheel and the driving distance obtained by the vehicle in the previous control cycle.

5. The vehicle driving control method according to claim 4, characterized in that: The obtaining of the rotational speed information of the corresponding wheel based on the output change of the wheel speed sensor of the wheel in the current control cycle includes: Respectively obtaining the number of rising edges and falling edges of the Hall sensor output signal wave of each wheel of the vehicle generated in the current control cycle; The number of rising edges and the number of falling edges represent the rotational speed of the corresponding wheel; The number of rising edges and the number of falling edges generated by the same Hall sensor output signal wave in the current control cycle constitute the speed information of the corresponding wheel.

6. The vehicle driving control method according to claim 5, characterized in that: The determining, based on the rotational speed information, the rotation angle information, the rolling radius, and the number of Hall sensor teeth corresponding to each wheel, of the wheel travel distance in the current control cycle, and obtaining the current travel distance of the vehicle based on the travel distance of each wheel and the travel distance obtained by the vehicle in the previous control cycle, includes: Determining a rolling radius and a number of Hall sensor teeth corresponding to each wheel of the vehicle; determining a wheel travel distance of each wheel in the current control cycle based on the rotation angle information of each wheel, the number of rising edges and the number of falling edges of the corresponding Hall sensor output signal wave generated in the current control cycle, the rolling radius of the wheel, and the number of Hall sensor teeth; Performing a mean calculation on the travel distances of the wheels within the current control period to obtain an average travel distance of the wheels of the vehicle within the current control period; The average wheel travel distance and the travel distance of the vehicle obtained in the previous control cycle are summed to obtain the current travel distance of the vehicle.

7. The vehicle driving control method according to claim 3, characterized in that: The performing fault detection on the wheel speed sensor corresponding to each wheel of the vehicle includes: Reading the fault flag of the wheel speed sensor corresponding to each wheel of the vehicle; If the fault flag of any of the wheel speed sensors is in a first state value, determining that the wheel speed sensor is in a fault state; If the fault flag of any of the wheel speed sensors is in the second state value, determining that the wheel speed sensor is in the valid state; Wherein, the fault flag of any of the wheel speed sensors is determined by performing fault diagnosis on the wheel speed sensor; If any of the wheel speed sensors switches from the fault state to the valid state, the fault flag of the wheel speed sensor is updated to the second state value; If any of the wheel speed sensors switches from the valid state to the fault state, the fault flag of the wheel speed sensor is updated to the first state value.

8. The vehicle driving control method according to any one of claims 1 to 3, characterized in that: The step of obtaining a target driving distance of the vehicle in response to a position control request for the vehicle includes any one of the following: In response to an input operation on a control panel of a vehicle, determining a position control flag and a target driving distance for the vehicle; the position control flag indicates whether a position control request for the vehicle is initiated; receiving a position control request and a target driving distance sent by a parking controller of the vehicle, wherein the target driving distance represents a driving distance of the vehicle in a parking mode; Receive a position control request and a target driving distance sent by the automatic driving controller of the vehicle; the target driving distance represents the driving distance of the vehicle in the automatic driving mode.

9. The vehicle driving control method according to claim 4, characterized in that: If the vehicle is a multi-motor vehicle, the drive motor torque refers to the sum of the torques of all the drive motors of the vehicle; If the current driving distance matches the target driving distance, controlling a parking brake enable parameter of the vehicle to be at a first parameter, a target drive motor torque of the vehicle to be zero, and setting a position control state of the vehicle to a state value indicating completion of control for the target driving distance; Wherein, the parking brake enabling parameter being at the first parameter indicates that the vehicle is parked; The position control status further includes one or more of a status value indicating that a position control request has not been initiated, a status value indicating a position control request response, a status value indicating that the response to the position control request has been terminated due to a fault in the Hall sensor, and a status value indicating that the obtained target driving distance is unreasonable; The acquired target driving distance being unreasonable indicates that the acquired target driving distance is smaller than a lower limit value of a driving distance for the vehicle, or is larger than an upper limit value of a driving distance for the vehicle.

10. A vehicle driving control device, characterized in that: The vehicle driving control device includes: a target driving distance acquisition module, configured to acquire a target driving distance of the vehicle in response to a position control request for a vehicle in a specific driving mode; the specific driving mode includes a low-speed driving mode and a starting mode; a current travel distance acquisition module, configured to acquire the current travel distance of the vehicle based on the rotational speed information and rotational angle information corresponding to each wheel of the vehicle; the rotational speed information is obtained based on the output change of the wheel speed sensor of the corresponding wheel within the current control cycle; a drive motor torque adjustment module, configured to determine that the current driving distance does not match the target driving distance, and to adjust the drive motor torque of the vehicle in the next control cycle so that a change in the driving speed of the vehicle in the specific driving mode is less than a vehicle speed change threshold, and an absolute value of the driving speed is less than a vehicle speed threshold.

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