A method, device, electronic device and storage medium for controlling vehicle speed on a bend

Abstract

The present application provides a curve vehicle speed control method, device, electronic device and storage medium, relating to the field of adaptive cruise. The method includes: when a current preview point is extracted in a lane curve, determining an initial curvature corresponding to the current preview point, and determining an initial curvature change rate according to a historical curvature corresponding to a previous preview point and the initial curvature; correcting the initial curvature change rate by using a change rate limit range to obtain a target curvature change rate, and correcting the initial curvature by using the target curvature change rate to obtain a target curvature, wherein the change rate limit range is generated according to the initial curvature and a preset basic change rate limit range, and the size of the change rate limit range is negatively correlated with the initial curvature; determining a target acceleration corresponding to the current preview point by using the target curvature so as to control the vehicle; and adaptively limiting and correcting the curve curvature calculated from the current preview point, thereby ensuring that the vehicle can smoothly accelerate and decelerate in the curve.

Description

Technical Field

[0001] The present application relates to the field of adaptive cruise control, and particularly to a method and device for controlling vehicle speed in a curve, an electronic device, and a computer-readable storage medium. Background Art

[0002] Adaptive Cruise Control (ACC) is a technology that can control a vehicle to drive automatically. When the driver turns on the adaptive cruise control function and the vehicle enters a curve, the adaptive cruise control module can actively adjust the vehicle speed according to the curve curvature determined from the data collected by the vehicle sensors to ensure that the vehicle can pass through the curve at a safe and comfortable speed. However, the curve curvature calculated based on the vehicle sensor data is prone to jump, which may easily lead to uneven acceleration and deceleration of the vehicle in the curve and may easily cause a sense of panic to the driver. Summary of the Invention

[0003] The purpose of the present application is to provide a method and device for controlling vehicle speed in a curve, an electronic device, and a computer-readable storage medium, which can adaptively limit and correct the curve curvature calculated from the current preview point, avoid the jump of the curve curvature, and thus ensure that the vehicle can smoothly accelerate and decelerate in the curve.

[0004] To solve the above technical problems, the present application provides a method for controlling vehicle speed in a curve, including:

[0005] When a current preview point is extracted in a lane curve, determine the initial curvature corresponding to the current preview point, and determine the initial curvature change rate according to the historical curvature corresponding to the previous preview point and the initial curvature;

[0006] Use the change rate limit range to correct the initial curvature change rate to obtain a target curvature change rate, and use the target curvature change rate to correct the initial curvature to obtain a target curvature, where the change rate limit range is generated according to the initial curvature and a preset basic change rate limit range, and the size of the change rate limit range is negatively correlated with the initial curvature;

[0007] Use the target curvature to determine the target acceleration corresponding to the current preview point to control the vehicle.

[0008] Preferably, the determining the initial curvature corresponding to the current preview point includes:

[0009] Obtain the current parameter values corresponding to the fitting parameters of each lane line, and construct a lane line equation using the current parameter values;

[0010] Determine the distance between the current preview point and the vehicle in the driving direction of the vehicle, and determine the initial curvature using the distance and the lane line equation.

[0011] Preferably, obtaining the current parameter values corresponding to the lane line fitting parameters includes:

[0012] Obtaining the current raw parameter values of each of the lane line fitting parameters from a vehicle sensor;

[0013] Performing a filtering process on the current raw parameter values to obtain the current parameter values.

[0014] Preferably, using the target curvature to determine the target acceleration corresponding to the current preview point includes:

[0015] Determining a corresponding maximum lateral target acceleration based on the target curvature, and using the maximum lateral target acceleration and the target curvature to determine the maximum speed of the vehicle at the current preview point;

[0016] Obtaining the current speed of the vehicle, and using the maximum speed, the current speed, and a preset time to determine the target acceleration.

[0017] Preferably, using the maximum speed, the current speed, and the preset time to determine the target acceleration includes:

[0018] When it is determined that the maximum speed is greater than the current speed, determining a corresponding speed correction coefficient based on the current speed; the magnitude of the speed correction coefficient is positively correlated with the current speed;

[0019] Using the maximum speed, the current speed, the speed correction coefficient, and the preset time to determine the target acceleration.

[0020] Preferably, after using the target curvature to determine the target acceleration corresponding to the current preview point, it further includes:

[0021] Determining a corresponding acceleration change rate according to the vehicle speed control action corresponding to the target acceleration, and sending the target acceleration and the acceleration change rate to an electronic stability control device of the vehicle, so that the electronic stability control device of the vehicle gradually adjusts the current acceleration of the vehicle to the target acceleration according to the acceleration change rate.

[0022] Preferably, determining the corresponding acceleration change rate according to the vehicle speed control action corresponding to the target acceleration includes:

[0023] When the vehicle speed control action is an acceleration action, determining a corresponding acceleration increase change rate based on the target curvature; the magnitude of the acceleration increase change rate is negatively correlated with the target curvature.

[0024] Preferably, after obtaining the target curvature by correcting the initial curvature using the target curvature change rate, the method further includes:

[0025] Determining a corresponding preview time based on the target curvature; the magnitude of the preview time is negatively correlated with the target curvature;

[0026] Extracting the next preview point in the lane curve based on the preview time.

[0027] Preferably, before obtaining the target curvature change rate by correcting the initial curvature change rate using the change rate limit range, the method further includes:

[0028] Determining a corresponding curvature correction coefficient based on the initial curvature; the magnitude of the curvature correction coefficient is negatively correlated with the initial curvature;

[0029] Multiplying the upper limit value and the lower limit value of the preset change rate base limit range by the curvature correction coefficient to obtain the change rate limit range.

[0030] Preferably, the step of obtaining the target curvature change rate by correcting the initial curvature change rate using the change rate limit range includes:

[0031] When it is determined that the initial curvature change rate is greater than or equal to zero, setting the target curvature change rate to the minimum value between the upper limit value in the change rate limit range and the initial curvature change rate;

[0032] When it is determined that the initial curvature change rate is less than zero, setting the target curvature change rate to the maximum value between the lower limit value in the change rate limit range and the initial curvature change rate.

[0033] The present application further provides a curve vehicle speed control device, including:

[0034] A curvature and curvature change rate determination module, configured to determine the initial curvature corresponding to the current preview point when a current preview point is extracted in a lane curve, and determine the initial curvature change rate according to the historical curvature corresponding to the previous preview point and the initial curvature;

[0035] A correction module, configured to correct the initial curvature change rate using the change rate limit range to obtain the target curvature change rate, and correct the initial curvature using the target curvature change rate to obtain the target curvature, wherein the change rate limit range is generated according to the initial curvature and a preset change rate base limit range, and the magnitude of the change rate limit range is negatively correlated with the initial curvature;

[0036] A target acceleration generation module, configured to determine the target acceleration corresponding to the current preview point using the target curvature to control the vehicle.

[0037] The present application also provides an electronic device, including:

[0038] a memory for storing a computer program;

[0039] a processor for implementing the curve vehicle speed control method as described above when executing the computer program.

[0040] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are loaded and executed by a processor, the curve vehicle speed control method as described above is implemented.

[0041] The present application provides a curve vehicle speed control method, including: when a current preview point is extracted in a lane curve, determining an initial curvature corresponding to the current preview point, and determining an initial curvature change rate according to a historical curvature corresponding to a previous preview point and the initial curvature; correcting the initial curvature change rate by using a change rate limit range to obtain a target curvature change rate, and correcting the initial curvature by using the target curvature change rate to obtain a target curvature, where the change rate limit range is generated according to the initial curvature and a preset basic change rate limit range, and the size of the change rate limit range is negatively correlated with the initial curvature; determining a target acceleration corresponding to the current preview point by using the target curvature to control the vehicle.

[0042] It can be seen that when the present application extracts a current preview point from a lane curve, it can first determine the initial curvature corresponding to the preview point and calculate the initial curvature change rate between the curvature and the historical curvature corresponding to the previous preview point; subsequently, the present application will correct the initial curvature change rate by using the change rate limit range to obtain a target curvature change rate, where the size of the change rate limit range is negatively correlated with the initial curvature, that is, the larger the initial curvature, the smaller the change rate limit range, and the smaller the initial curvature, the larger the change rate limit range. Considering that the curve curvature is larger closer to the center of the curve, the present application can gradually increase the limit degree of the curvature change rate during the process of the vehicle gradually approaching the center of the curve, so as to avoid the jump of the curve curvature; further, after re-correcting the initial curvature by using the above target curvature change rate to obtain the target curvature, the present application can generate a target acceleration corresponding to the current preview point by using the target curvature and control the vehicle speed by using the target acceleration, which can ensure that the target acceleration does not jump, and further ensure that the vehicle smoothly performs acceleration and deceleration actions in the curve to improve the driving experience of the driver. The present application also provides a curve vehicle speed control device, an electronic device and a storage medium, which have the above beneficial effects. Description of the Drawings

[0043] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the provided drawings.

[0044] Figure 1 A flowchart of a curve vehicle speed control method provided by an embodiment of the present application;

[0045] Figure 2 A schematic diagram of a lane curve provided by an embodiment of the present application;

[0046] Figure 3 A structural block diagram of a curve vehicle speed control device provided by an embodiment of the present application;

[0047] Figure 4 A structural block diagram of an electronic device provided by an embodiment of the present application. Detailed implementation manners

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0049] It can be understood that to provide a good driving experience for the driver and avoid causing a sense of panic to the driver, a vehicle with the adaptive cruise function enabled should be able to drive smoothly in a curve. For example, it should smoothly decelerate to a safe entry speed before entering the curve, slowly adjust the vehicle speed while driving in the curve, and smoothly accelerate when exiting the curve. That is, simply put, during the process of driving in a curve, the acceleration of the vehicle should change smoothly. However, the acceleration data used for adaptive cruise is usually calculated based on the curve curvature, and the curve curvature is calculated using vehicle sensor data. Affected by factors such as light and obstacle occlusion, the vehicle sensor data is prone to jump, which in turn easily causes the curve curvature and acceleration data to jump. This ultimately easily leads to the situation that a vehicle with the adaptive cruise function enabled suddenly accelerates or decelerates in a curve, that is, the vehicle's acceleration and deceleration are not smooth during curve driving, and it is easy to cause a sense of panic to the driver. In view of this, the present application can provide a curve vehicle speed control method, which can adaptively limit and correct the curve curvature calculated from vehicle sensor data, thereby avoiding the jump of the curve curvature and ensuring that the vehicle can accelerate and decelerate smoothly in the curve.

[0050] It should be noted that the execution subject of the method in the embodiments of the present application is not limited. It can be a vehicle computer or other terminal devices that can process vehicle sensor data and interact with the vehicle controller, such as a personal computer, a mobile terminal, etc.

[0051] Please refer to Figure 1 , Figure 1 , which is a flowchart of a curve speed control method provided by the embodiments of the present application. The method may include:

[0052] S100. When the current preview point is extracted in the lane curve, determine the initial curvature corresponding to the current preview point, and determine the initial curvature change rate according to the historical curvature corresponding to the previous preview point and the initial curvature.

[0053] In the embodiments of the present application, the preview point is a point pre-aimed on the vehicle driving path. The vehicle sensor can sense the curve change situation corresponding to this point and generate sensor data, so as to calculate the curve curvature corresponding to this preview point by using these data, and control the vehicle to accelerate or decelerate according to the curvature. It can be understood that the curve curvature is constantly changing. Therefore, in the actual application process, the preview point will be continuously determined to continuously sense the change situation of the curve curvature. It should be noted that in the existing solution, after calculating the curve curvature corresponding to the current preview point by using the sensor data, the acceleration data will be immediately calculated by using this curve curvature. However, as described above, the sensor data is prone to jump, which is likely to affect the reliability of the curve curvature. If the unreliable curve curvature is directly used to calculate the acceleration data, it is likely to affect the driving smoothness of the vehicle in the process of entering the curve, driving in the curve and exiting the curve, and is likely to reduce the driving experience of the driver. Therefore, in the embodiments of the present application, the curve curvature corresponding to the current preview point calculated by using the sensor data can only be used as the "initial curvature" and cannot be directly used for acceleration data calculation. The embodiments of the present application will default that the "initial curvature" has a large jump risk and is unreliable, and needs to be corrected before it can be used for acceleration data calculation. After determining the initial curvature, the embodiments of the present application also determine the initial curvature change rate between it and the historical curvature corresponding to the previous preview point. This change rate can reflect the jump situation between the initial curvature and the historical curvature, and then the initial curvature can be corrected by correcting the initial curvature change rate, where the historical curvature is the curvature data obtained after correcting the previous preview point. The initial curvature change rate can be specifically calculated by the following formula:

[0054] kapDt = (kap – kapK1) / tDtSys.

[0055] Among them, kapDt represents the initial curvature change rate, kap represents the initial curvature, kapK1 represents the historical curvature, and tDtSys represents the system time constant.

[0056] It should be noted that the embodiments of the present application do not limit the method for determining the preview point. Please refer to the related technologies of adaptive cruise. The embodiments of the present application also do not limit the specific method for determining the initial curvature corresponding to the current preview point. Generally, the lane line equation can be constructed using the current parameter values corresponding to the fitting parameters of each lane line collected by the vehicle sensor. In addition, the separation distance between the current preview point and the vehicle in the driving direction of the vehicle can be determined, and then the initial curvature corresponding to the current preview point can be determined through the separation distance and the lane line equation.

[0057] In a possible case, determining the initial curvature corresponding to the current preview point may include:

[0058] S110: Obtain the current parameter values corresponding to the fitting parameters of each lane line, and construct a lane line equation using the current parameter values;

[0059] S120: Determine the separation distance between the current preview point and the vehicle in the driving direction of the vehicle, and determine the initial curvature using the separation distance and the lane line equation.

[0060] It should be particularly noted that the driving direction refers to the direction pointed by the current vehicle head. Please refer to Figure 2 , Figure 2 is a schematic diagram of a lane curve provided by the embodiments of the present application. Among them, 10 represents the vehicle, 11 represents the current preview point, and the length corresponding to the arrow 12 is the separation distance between the current preview point and the vehicle in the driving direction of the vehicle. The above separation distance can be calculated by the following formula:

[0061]

[0062] where x represents the separation distance, v ref represents the current speed of the vehicle, a ref represents the current acceleration of the vehicle, and t predict represents the preset time.

[0063] It should be noted that the embodiments of the present application do not limit the specific lane line fitting parameters. The related technologies of lane line fitting can be referred to. For example, it may include parameters such as road curvature C0, road curvature change rate C1, heading angle ψ, dy0, etc. The embodiments of the present application also do not limit the specific lane line equation. For example, it can be:

[0064]

[0065] Taking the first derivative and the second derivative of the above equation, the first derivative and the second derivative are obtained as follows:

[0066]

[0067] y” = c1x + c0;

[0068] Subsequently, the initial curvature kap corresponding to the current preview point can be calculated according to the curvature calculation formula:

[0069]

[0070] Of course, the parameter values provided by vehicle sensors are prone to large fluctuations, which will significantly affect the accuracy of the initial curvature. Therefore, in the embodiments of the present application, the original parameter values output by vehicle sensors will not be directly used to calculate the initial curvature. Instead, after filtering them to obtain high-quality current parameter values, the initial curvature will be calculated using these values, so as to reduce the fluctuations of the fitting parameters of each lane line.

[0071] In a possible case, obtaining the current parameter values corresponding to the fitting parameters of each lane line may include:

[0072] S111: Obtain the current original parameter values of the fitting parameters of each lane line from the vehicle sensor;

[0073] S112: Filter the current original parameter values to obtain the current parameter values.

[0074] It should be noted that the embodiments of the present application do not limit the specific filtering method. For example, it can be a low-pass filter (PT1 filter).

[0075] S200. Modify the initial curvature change rate using the change rate limit range to obtain the target curvature change rate, and modify the initial curvature using the target curvature change rate to obtain the target curvature, where the change rate limit range is generated according to the initial curvature and the preset basic change rate limit range, and the size of the change rate limit range is negatively correlated with the initial curvature.

[0076] In the embodiments of the present application, the intensity for restricting and correcting the change rate of the initial curvature is determined according to the magnitude of the initial curvature, and the change rate of the initial curvature is corrected according to this intensity. It can be understood that when the vehicle gradually approaches the center of the curve, the curvature corresponding to the curve will gradually increase. At this time, the vehicle should further stabilize the vehicle speed control to avoid unstable cornering of the vehicle. In addition, for a suddenly increased curvature, a stronger intensity should also be taken to restrict and correct it. Therefore, as the curvature increases, the intensity of restricting and correcting the change rate of the initial curvature should be further strengthened to avoid generating a suddenly increased curvature and prevent the vehicle from running unstably in the curve. Therefore, there is a positive correlation between the magnitude of the initial curvature and the restriction intensity. Specifically, in the embodiments of the present application, the change rate limit range is used to restrict and correct the change rate of the initial curvature, where the change rate limit range is constructed based on a preset change rate basic limit range, and its range size is negatively correlated with the initial curvature, that is, the larger the initial curvature, the smaller the change rate limit range, and the smaller the initial curvature, the larger the change rate limit range. It should be noted that the change rate limit range is used to limit the value of the change rate of the initial curvature. For example, when the change rate of the initial curvature is greater than the upper limit value of the change rate limit range, the embodiments of the present application will update the change rate of the initial curvature with the upper limit value; when the change rate of the initial curvature is less than the lower limit value of the change rate limit range, the embodiments of the present application will update the change rate of the initial curvature with the lower limit value. In this way, it can be ensured that the change rate of the initial curvature does not exceed the limit range, and thus a jumping curvature can be avoided. In addition, since the size of the change rate limit range is negatively correlated with the magnitude of the initial curvature, when the vehicle gradually approaches the center of the curve and the curve curvature gradually increases, the embodiments of the present application can gradually increase the degree of restriction on the curvature change rate to enhance the smoothness of the vehicle running in the curve. Specifically, the change rate limit range can be generated based on a preset change rate basic limit range. For example, the upper limit value and the lower limit value of the preset change rate basic limit range can be multiplied by corresponding curvature correction coefficients, where the magnitude of the curvature correction coefficient is negatively correlated with the initial curvature. It should be noted that the embodiments of the present application do not limit the specific manner of determining the curvature correction coefficient based on the initial curvature. For example, a conversion relationship between the initial curvature and the curvature correction coefficient can be set, and the curvature correction coefficient can be calculated using the initial curvature and this conversion relationship. Multiple curvature intervals can also be set, and corresponding curvature correction coefficients are set for each curvature interval according to the negative correlation relationship. Then, the target curvature correction coefficient corresponding to the initial curvature can be determined according to the interval where the initial curvature is located. That is, the curvature correction coefficient can be calculated using the initial curvature or obtained by looking up a table using the initial curvature, and can be set according to actual application requirements. In the embodiments of the present application, for the convenience of setting, the curvature correction coefficient can be obtained by looking up a table using the initial curvature.Furthermore, the embodiments of the present application do not limit the specific upper and lower limit values of the preset change rate base limit range, nor do they limit whether the curvature correction coefficients corresponding to the upper and lower limit values are the same. For example, to enhance the setting flexibility, two different sets of curvature correction coefficients can be separately set for the upper and lower limit values. Or, for the convenience of setting, the same curvature correction coefficient can also be set for the upper and lower limit values, and the selection can be made according to actual application requirements. In the embodiments of the present application, to improve the convenience of setting, the same curvature correction coefficient can be set for the upper and lower limit values of the preset change rate base limit range.

[0077] In a possible case, before using the change rate limit range to correct the initial curvature change rate to obtain the target curvature change rate, it may further include:

[0078] S211. Determine the corresponding curvature correction coefficient based on the initial curvature; the magnitude of the curvature correction coefficient is negatively correlated with the initial curvature;

[0079] S212. Multiply the upper limit value and the lower limit value of the preset change rate base limit range by the curvature correction coefficient to obtain the change rate limit range.

[0080] The following uses an actual example to introduce the generation process and usage method of the change rate limit range. The upper limit value of the change rate limit range kapDt = min(kapDt, CSCDeltaKapMax * kapFactor), and the lower limit value of this range kapDt = max(kapDt, CSCDeltaKapMin * kapFactor), where CSCDeltaKapMax and CSCDeltaKapMin are both calibratable upper limit base value and lower limit base value. CSCDeltaKapMax and CSCDeltaKapMin together constitute the preset change rate base limit range, and KapFactor represents the curvature correction coefficient. The curvature correction coefficient is obtained by looking up a table based on the initial curvature. When the curvature of the curve is large, the curvature correction coefficient should be a little smaller; when the curvature of the curve is small, the curvature correction coefficient should be a little larger. In this way, when the radius of the curve increases inside the curve, the curvature change can be made slower to prevent excessive acceleration. At the same time, it can also ensure that when exiting the curve (the radius of the curve decreases and the curvature correction coefficient is adjusted larger), the acceleration will not be too slow.

[0081] As described above, the change rate limit range is used to limit the value of the initial curvature change rate. Therefore, when the initial curvature change rate is greater than the upper limit value of the change rate limit range, the embodiments of the present application will use the upper limit value to update the initial curvature change rate; when the initial curvature change rate is less than the lower limit value of the change rate limit range, the embodiments of the present application will use the lower limit value to update the initial curvature change rate.

[0082] In a possible scenario, correcting the initial curvature change rate using the rate-of-change limit range to obtain the target curvature change rate may include:

[0083] S221. When it is determined that the initial curvature change rate is greater than or equal to zero, set the target curvature change rate to the minimum value between the upper limit value in the rate-of-change limit range and the initial curvature change rate;

[0084] S222. When it is determined that the initial curvature change rate is less than zero, set the target curvature change rate to the maximum value between the lower limit value in the rate-of-change limit range and the initial curvature change rate.

[0085] Furthermore, the target curvature obtained after correction can be calculated by the following formula:

[0086] kap = kap + kapDt * tDtSys;

[0087] Where, kap on the left side of the equation represents the target curvature, and kap on the right side of the equation represents the initial curvature.

[0088] S300. Use the target curvature to determine the target acceleration corresponding to the current preview point to control the vehicle.

[0089] When the driver turns on the adaptive cruise control function and enters a curve from a straight road, the vehicle controller will first calculate the interval distance in the driving direction between the current preview point and the vehicle and the target curvature of the current preview point; Subsequently, the maximum lateral acceleration a of the vehicle at the target curvature can be determined y , and according to the relationship between the highest vehicle speed corresponding to the current preview point, the lateral acceleration, and the curve curvature Calculate the highest vehicle speed, and then the target acceleration a for speed reduction in the curve can be obtained according to (v csc - v display ) / T. Where, v csc is the current speed of the vehicle, and T is the time required to reach v display . a csc represents the target acceleration. It should be noted that between the target curvature and the maximum lateral acceleration, either a conversion relation can be preset and implemented through calculation, or a conversion table can be set and conversion can be performed by looking up the table, which can be set according to actual application requirements. csc

[0090] In a possible scenario, using the target curvature to determine the target acceleration corresponding to the current preview point may include:

[0091] S310. Determine the corresponding maximum lateral target acceleration based on the target curvature, and use the maximum lateral target acceleration and the target curvature to determine the maximum speed of the vehicle at the current preview point;

[0092] S320. Obtain the current speed of the vehicle, and determine the target acceleration using the maximum speed, the current speed, and a preset time.

[0093] Of course, to avoid too rapid speed adjustment of the vehicle in a curve, a speed correction coefficient corresponding to the current vehicle speed can also be added when calculating the target acceleration. Specifically, the magnitude of the speed correction coefficient is positively correlated with the current speed. The target acceleration calculated using this coefficient can be expressed as:

[0094]

[0095] Where factor represents the speed correction coefficient. When the vehicle speed is higher, factor is larger, and thus the acceleration can be made smaller. Of course, this correction can also be performed only when it is determined that the maximum speed is greater than the current speed, that is, when the vehicle needs to accelerate, and no processing is done for the deceleration condition. It should be noted that the conversion relationship between the vehicle speed and the speed correction coefficient can either be preset and implemented through calculation, or a conversion table can be set up and the conversion can be performed by looking up the table, which can be set according to actual application requirements.

[0096] In a possible case, determining the target acceleration using the maximum speed, the current speed, and a preset time may include:

[0097] S321. When it is determined that the maximum speed is greater than the current speed, determine the corresponding speed correction coefficient based on the current speed; the magnitude of the speed correction coefficient is positively correlated with the current speed;

[0098] S322. Determine the target acceleration using the maximum speed, the current speed, the speed correction coefficient, and the preset time.

[0099] Furthermore, to ensure smooth acceleration or deceleration of the vehicle and avoid the sense of fear that may be brought to the driver when the vehicle suddenly adjusts the acceleration to the target acceleration, the embodiment of the present application can also control the vehicle to smoothly adjust the current acceleration to the target acceleration. Specifically, the corresponding acceleration change rate can be determined according to the vehicle speed control action corresponding to the target acceleration. For example, the corresponding acceleration increase change rate is determined for the acceleration action, and the corresponding deceleration acceleration change rate is determined for the deceleration action. Subsequently, the target acceleration and the above preset change rate are sent to the Electronic Stability Controller (ESC) of the vehicle, so that the Electronic Stability Controller of the vehicle gradually adjusts the current acceleration of the vehicle to the target acceleration according to the preset acceleration change rate.

[0100] In a possible case, controlling the speed of the vehicle using the target acceleration may include:

[0101] S330. Determine the corresponding acceleration change rate according to the vehicle speed control action corresponding to the target acceleration, and send the target acceleration and the acceleration change rate to the vehicle's electronic stability control device of the vehicle, so that the electronic stability control device of the vehicle gradually adjusts the current acceleration of the vehicle to the target acceleration according to the acceleration change rate.

[0102] It should be noted that the embodiments of the present application do not limit the specific setting methods of the acceleration change rate during acceleration and the acceleration change rate during deceleration. For example, considering that the speed reduction in a curve is a scenario mainly dominated by deceleration, the acceleration change rate during acceleration can be set to a relatively small value, such as 0.2 m / s 3 , so as to avoid jerks when the vehicle switches from deceleration to acceleration within the curve; in addition, the acceleration change rate during acceleration can also be corrected based on the curve curvature. When the curvature is larger, the acceleration change rate during acceleration is smaller, and the acceleration is slower, so as to improve the smoothness of acceleration. It should be noted that a conversion relationship formula can be preset between the target curvature and the acceleration change rate during acceleration, and the conversion can be achieved through calculation, or a conversion table can be set, and the conversion can be performed by looking up the table, which can be set according to actual application requirements.

[0103] In a possible case, determining the corresponding preset change rate according to the vehicle speed control action corresponding to the target acceleration may include:

[0104] S331. When the vehicle speed control action is an acceleration action, determine the corresponding acceleration change rate during acceleration based on the target curvature; the magnitude of the acceleration change rate during acceleration is negatively correlated with the target curvature.

[0105] Finally, considering that after the vehicle enters the curve, the accuracy of the lane line fitting parameters extracted by the vehicle sensor in the curve will decrease, which will easily lead to fluctuations in the curve curvature. Therefore, a logic for correcting the preview time based on the curve curvature can be added, that is, the larger the curve curvature, the smaller the preview time, and the smaller the curve curvature, the larger the preview time. Thus, the fluctuations of the lane line fitting parameters can be reduced by appropriately reducing the preview time within a large curve, so as to ensure more accurate prediction of the preview point curvature and weaken the curvature fluctuations caused by inaccurate preview. It should be noted that a conversion relationship formula can be preset between the target curvature and the preview time, and the conversion can be achieved through calculation, or a conversion table can be set, and the conversion can be performed by looking up the table, which can be set according to actual application requirements.

[0106] In a possible case, after obtaining the target curvature by correcting the initial curvature using the target curvature change rate, it may further include:

[0107] S400. Determine the corresponding preview time based on the target curvature; the magnitude of the preview time is negatively correlated with the target curvature;

[0108] S500. Extract the next preview point in the lane curve based on the preview time.

[0109] It should be noted that the specific correspondence between the target curvature and the preview time in the embodiments of the present application is not limited and can be set according to actual application requirements.

[0110] Based on the above embodiments, when the current preview point is extracted from the lane curve, the present application can first determine the initial curvature corresponding to the preview point and calculate the initial curvature change rate between the curvature and the historical curvature corresponding to the previous preview point. Subsequently, the present application will use the change rate limit range to correct the initial curvature change rate to obtain the target curvature change rate, where the size of the change rate limit range is negatively correlated with the initial curvature, that is, the larger the initial curvature, the smaller the change rate limit range, and the smaller the initial curvature, the larger the change rate limit range. Considering that the curvature of the curve is larger the closer it is to the center of the curve, the present application can gradually increase the degree of restriction on the curvature change rate as the vehicle gradually approaches the center of the curve, so as to avoid jumps in the curve curvature. Further, after using the above target curvature change rate to correct the initial curvature to obtain the target curvature, the present application can generate the target acceleration corresponding to the current preview point using the target curvature and use the target acceleration to control the speed of the vehicle, which can ensure that the target acceleration does not jump, and further ensure that the vehicle smoothly performs acceleration and deceleration actions in the curve to improve the driving experience of the driver.

[0111] Next, the lane curve speed control device, electronic device, and computer-readable storage medium provided by the embodiments of the present application will be introduced. The lane curve speed control device, electronic device, and computer-readable storage medium described below can be mutually corresponding and referred to the lane curve speed control method described above.

[0112] Please refer to Figure 3 , Figure 3 which is a structural block diagram of a lane curve speed control device provided by an embodiment of the present application. The device may include:

[0113] A curvature and curvature change rate determination module 301, configured to determine the initial curvature corresponding to the current preview point when the current preview point is extracted from the lane curve, and determine the initial curvature change rate according to the historical curvature corresponding to the previous preview point and the initial curvature;

[0114] A correction module 302, configured to correct the initial curvature change rate using the change rate limit range to obtain the target curvature change rate, and correct the initial curvature using the target curvature change rate to obtain the target curvature, where the change rate limit range is generated according to the initial curvature and a preset change rate basic limit range, and the size of the change rate limit range is negatively correlated with the initial curvature;

[0115] The target acceleration generation module 303 is configured to determine the target acceleration corresponding to the current preview point by using the target curvature, so as to control the vehicle.

[0116] Optionally, the curvature and curvature change rate determination module 301 may include:

[0117] The equation constructor sub-module is configured to obtain the current parameter values corresponding to the fitting parameters of each lane line, and construct a lane line equation by using the current parameter values;

[0118] The curvature determination sub-module is configured to determine the separation distance between the current preview point and the vehicle in the driving direction of the vehicle, and determine the initial curvature by using the separation distance and the lane line equation.

[0119] Optionally, the equation constructor sub-module may include:

[0120] The acquisition unit is configured to acquire the current raw parameter values of the fitting parameters of each lane line from the vehicle sensor;

[0121] The filtering unit is configured to perform filtering processing on the current raw parameter values to obtain the current parameter values.

[0122] Optionally, the target acceleration generation module 303 includes:

[0123] The maximum speed determination sub-module is configured to determine the corresponding maximum lateral target acceleration based on the target curvature, and determine the maximum speed of the vehicle at the current preview point by using the maximum lateral target acceleration and the target curvature;

[0124] The target acceleration sub-generation sub-module is configured to acquire the current speed of the vehicle, and determine the target acceleration by using the maximum speed, the current speed, and the preset time.

[0125] Optionally, the target acceleration sub-generation sub-module includes:

[0126] The speed correction coefficient determination unit is configured to, when it is determined that the maximum speed is greater than the current speed, determine the corresponding speed correction coefficient based on the current speed; the magnitude of the speed correction coefficient is positively correlated with the current speed;

[0127] The target acceleration sub-generation unit is configured to determine the target acceleration by using the maximum speed, the current speed, the speed correction coefficient, and the preset time.

[0128] Optionally, the target acceleration generation module 303 may include:

[0129] A control sub-module, configured to determine a corresponding acceleration change rate according to the vehicle speed control action corresponding to the target acceleration, and send the target acceleration and the acceleration change rate to the vehicle's electronic stability control device, so that the vehicle's electronic stability control device gradually adjusts the current acceleration of the vehicle to the target acceleration according to the acceleration change rate.

[0130] Optionally, the control sub-module includes:

[0131] An acceleration change rate extraction and determination unit, configured to, when the vehicle speed control action is an acceleration action, determine a corresponding extracted acceleration change rate based on the target curvature; the magnitude of the extracted acceleration change rate is negatively correlated with the target curvature.

[0132] Optionally, the device may further include:

[0133] A preview time determination module, configured to determine a corresponding preview time based on the target curvature; the magnitude of the preview time is negatively correlated with the target curvature;

[0134] A preview point extraction module, configured to extract the next preview point in the lane curve based on the preview time.

[0135] Optionally, the device may further include:

[0136] A curvature correction coefficient determination module, configured to determine a corresponding curvature correction coefficient based on the initial curvature; the magnitude of the curvature correction coefficient is negatively correlated with the initial curvature;

[0137] A change rate limit range generation module, configured to multiply the upper limit value and the lower limit value of the preset change rate basic limit range by the curvature correction coefficient to obtain the change rate limit range.

[0138] Optionally, the correction module 302 may include:

[0139] A first correction sub-module, configured to, when it is determined that the initial curvature change rate is greater than or equal to zero, set the target curvature change rate to the minimum value between the upper limit value in the change rate limit range and the initial curvature change rate;

[0140] A second correction sub-module, configured to, when it is determined that the initial curvature change rate is less than zero, set the target curvature change rate to the maximum value between the lower limit value in the change rate limit range and the initial curvature change rate.

[0141] Please refer to Figure 4 , Figure 4 , which is a structural block diagram of an electronic device provided by an embodiment of the present application. An embodiment of the present application provides an electronic device 20, including a processor 21 and a memory 22; wherein, the memory 22 is used to store a computer program; the processor 21 is used to execute the curve vehicle speed control method provided by the foregoing embodiment when executing the computer program.

[0142] For the specific process of the above-mentioned curved road vehicle speed control method, reference can be made to the corresponding content provided in the foregoing embodiments, and details will not be repeated here.

[0143] Moreover, as a carrier for resource storage, the memory 22 can be a read-only memory, a random access memory, a magnetic disk, an optical disc, etc., and the storage method can be temporary storage or permanent storage.

[0144] In addition, the electronic device 20 further includes a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. Among them, the power supply 23 is used to provide operating voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and external devices, and the communication protocol it follows is any communication protocol applicable to the technical solution of this application, and specific limitations are not imposed here; the input / output interface 25 is used to obtain external input data or output data to the outside, and its specific interface type can be selected according to specific application requirements, and specific limitations are not imposed here.

[0145] Furthermore, an embodiment of the present application also provides a computer-readable storage medium for storing a computer program, where the computer program, when executed by a processor, implements the curved road vehicle speed control method provided in the foregoing embodiments.

[0146] For the specific process of the above-mentioned curved road vehicle speed control method, reference can be made to the corresponding content provided in the foregoing embodiments, and details will not be repeated here.

[0147] The various embodiments in the specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts among the various embodiments can be referred to each other. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0148] Those skilled in the art can further realize that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the components and steps of the examples have been generally described according to their functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0149] The steps of the methods or algorithms described in connection with the embodiments disclosed herein may be implemented directly in hardware, in software modules executed by a processor, or in a combination thereof. The software modules may be located in random access memory (RAM), memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium well known in the art.

[0150] The above has introduced in detail a method, apparatus, electronic device and storage medium for controlling vehicle speed on a curve provided by the present application. Specific examples are used herein to illustrate the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A method for controlling vehicle speed on a curve, characterized in that, Including: When a current preview point is extracted in a lane curve, determining an initial curvature corresponding to the current preview point, and determining an initial curvature change rate according to a historical curvature corresponding to a previous preview point and the initial curvature; Determining a corresponding curvature correction coefficient based on the initial curvature; the magnitude of the curvature correction coefficient is negatively correlated with the initial curvature; Multiplying an upper limit value and a lower limit value of a preset change rate base limit range by the curvature correction coefficient to obtain a change rate limit range; Using the change rate limit range to correct the initial curvature change rate to obtain a target curvature change rate, and using the target curvature change rate to correct the initial curvature to obtain a target curvature; wherein the change rate limit range is generated according to the initial curvature and a preset change rate base limit range, and the magnitude of the change rate limit range is negatively correlated with the initial curvature; Using the target curvature to determine a target acceleration corresponding to the current preview point to control the vehicle; The using the change rate limit range to correct the initial curvature change rate to obtain a target curvature change rate includes: When it is determined that the initial curvature change rate is greater than or equal to zero, setting the target curvature change rate to the minimum value between the upper limit value in the change rate limit range and the initial curvature change rate; When it is determined that the initial curvature change rate is less than zero, setting the target curvature change rate to the maximum value between the lower limit value in the change rate limit range and the initial curvature change rate.

2. The curve vehicle speed control method according to claim 1, wherein The determining the initial curvature corresponding to the current preview point includes: Obtaining current parameter values corresponding to respective lane line fitting parameters, and constructing a lane line equation using the current parameter values; Determining a separation distance between the current preview point and the vehicle in the driving direction of the vehicle, and determining the initial curvature using the separation distance and the lane line equation.

3. The curve vehicle speed control method according to claim 2, characterized in that The obtaining the current parameter values corresponding to respective lane line fitting parameters includes: Obtaining current raw parameter values of respective lane line fitting parameters from a vehicle sensor; Performing a filtering process on the current raw parameter values to obtain the current parameter values.

4. The bend vehicle speed control method according to claim 1, characterized in that, The using the target curvature to determine a target acceleration corresponding to the current preview point includes: Determining a maximum lateral target acceleration corresponding to the target curvature, and determining a maximum speed of the vehicle at the current preview point using the maximum lateral target acceleration and the target curvature; Obtaining a current speed of the vehicle, and determining the target acceleration using the maximum speed, the current speed, and a preset time.

5. The curve vehicle speed control method according to claim 4, characterized in that, The using the maximum speed, the current speed, and the preset time to determine the target acceleration includes: When it is determined that the maximum speed is greater than the current speed, determining a corresponding speed correction coefficient based on the current speed; the magnitude of the speed correction coefficient is positively correlated with the current speed; Determining the target acceleration using the maximum speed, the current speed, the speed correction coefficient, and the preset time.

6. The bend vehicle speed control method according to claim 1, characterized in that, After using the target curvature to determine a target acceleration corresponding to the current preview point, further including: Determine the corresponding acceleration change rate according to the vehicle speed control action corresponding to the target acceleration, and send the target acceleration and the acceleration change rate to the electronic stability control device of the vehicle, so that the electronic stability control device of the vehicle gradually adjusts the current acceleration of the vehicle to the target acceleration according to the acceleration change rate.

7. The curve vehicle speed control method according to claim 6, wherein The determining the corresponding acceleration change rate according to the vehicle speed control action corresponding to the target acceleration includes: When the vehicle speed control action is an acceleration action, determine the corresponding acceleration change rate for speed increase based on the target curvature; the magnitude of the acceleration change rate for speed increase is negatively correlated with the target curvature.

8. The bend vehicle speed control method according to claim 1, wherein After obtaining the target curvature by correcting the initial curvature with the target curvature change rate, it further includes: Determine the corresponding preview time based on the target curvature; the magnitude of the preview time is negatively correlated with the target curvature; Extract the next preview point in the lane curve based on the preview time.

9. A bend vehicle speed control device, characterized in that, It includes: A curvature and curvature change rate determination module, configured to determine the initial curvature corresponding to the current preview point when the current preview point is extracted in the lane curve, and determine the initial curvature change rate according to the historical curvature corresponding to the previous preview point and the initial curvature; A correction module, configured to correct the initial curvature change rate with the change rate limit range to obtain the target curvature change rate, and correct the initial curvature with the target curvature change rate to obtain the target curvature, where the change rate limit range is generated according to the initial curvature and the preset change rate basic limit range, and the magnitude of the change rate limit range is negatively correlated with the initial curvature; A target acceleration generation module, configured to determine the target acceleration corresponding to the current preview point using the target curvature to control the vehicle; A curvature correction coefficient determination module, configured to determine the corresponding curvature correction coefficient based on the initial curvature; the magnitude of the curvature correction coefficient is negatively correlated with the initial curvature; A change rate limit range generation module, configured to multiply the upper limit value and the lower limit value of the preset change rate basic limit range by the curvature correction coefficient to obtain the change rate limit range; A first correction sub-module, configured to set the target curvature change rate to the minimum value between the upper limit value in the change rate limit range and the initial curvature change rate when it is determined that the initial curvature change rate is greater than or equal to zero; A second correction sub-module, configured to set the target curvature change rate to the maximum value between the lower limit value in the change rate limit range and the initial curvature change rate when it is determined that the initial curvature change rate is less than zero.

10. An electronic device, characterized in that, It includes: A memory, configured to store a computer program; A processor, configured to implement the curve vehicle speed control method according to any one of claims 1 to 8 when executing the computer program.

11. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are loaded and executed by the processor, the curve vehicle speed control method according to any one of claims 1 to 8 is implemented.

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