Vehicle braking distance detection method and device, electronic equipment and storage medium

Abstract

The invention provides a vehicle braking distance detection method and device, electronic equipment and a storage medium, and relates to the technical field of automatic driving and unmanned vehicles. The method comprises the steps that braking data information of a target vehicle in the braking process is obtained; based on the braking data information, the actual braking effect of the target vehicle is evaluated, and braking effect evaluation parameters are obtained; on the basis of the braking effect evaluation parameters, a braking distance model of the target vehicle is updated, an updated braking distance model is obtained, and the braking distance model represents the function relation between the current vehicle speed of the target vehicle and the braking distance; and the braking distance of the target vehicle is determined based on the updated braking distance model, so that the accuracy of vehicle braking distance detection is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical fields of automatic driving and unmanned vehicles, and in particular to a method and device for detecting a braking distance of a vehicle, an electronic device and a storage medium. Background Art

[0002] For unmanned mining vehicles, accurate vehicle braking distance is a key indicator to ensure the safety and efficiency of unmanned mining vehicle production and operation. At present, the braking distance model of the vehicle is often established using the offline data of some vehicles during the new vehicle adaptation stage, and the braking distance model used by all vehicles of the same model is the same.

[0003] However, due to the large manufacturing process deviation of unmanned mining vehicles, the braking system response characteristics of different vehicles of the same model also vary to a certain extent. Therefore, for some vehicles, the braking distance model used is inaccurate. In addition, as the vehicle is used, the performance of the vehicle's braking system will decay, and the vehicle's braking distance model is inaccurate for mining vehicles with decayed braking performance. Summary of the invention

[0004] In view of this, the present disclosure provides a method and device for detecting a braking distance of a vehicle, an electronic device, and a storage medium.

[0005] In a first aspect, a method for detecting a braking distance of a vehicle is provided, comprising: obtaining braking data information of a target vehicle during a braking process; evaluating an actual braking effect of the target vehicle based on the braking data information to obtain a braking effect evaluation parameter; updating a braking distance model of the target vehicle based on the braking effect evaluation parameter to obtain an updated braking distance model, wherein the braking distance model represents a functional relationship between a current vehicle speed and a braking distance of the target vehicle; and determining a braking distance of the target vehicle based on the updated braking distance model.

[0006] In some embodiments, the braking effect evaluation parameter includes a maximum braking force evaluation parameter and / or a braking response delay evaluation parameter. Based on the braking data information, the actual braking effect of the target vehicle is evaluated to obtain the braking effect evaluation parameter, including: determining the actual braking deceleration information of the target vehicle during the braking process based on the braking data information; determining the maximum braking force evaluation parameter based on the actual braking deceleration information and the braking command information of the target vehicle during the braking process; and / or determining the braking response delay evaluation parameter based on the braking data information.

[0007] In some embodiments, based on the actual braking deceleration information and the braking command information of the target vehicle during braking, the maximum braking force evaluation parameter is determined, including: obtaining a braking performance model of the target vehicle, the braking performance model characterizing the functional relationship between the braking command value corresponding to the braking command information and the expected braking deceleration; determining the expected braking deceleration information based on the braking performance model and the braking command information; determining the maximum braking force evaluation parameter based on the expected braking deceleration information and the actual braking deceleration information. Optionally, the method for constructing the braking performance model includes: when the target vehicle is traveling at the highest speed, requesting multiple braking commands respectively, each of which corresponds to a different braking command value; for each braking command, determining the actual deceleration value of the target vehicle under the braking command; constructing the braking performance model based on the braking command values ​​corresponding to each of the multiple braking commands and the actual deceleration values ​​corresponding to each of the multiple braking commands.

[0008] In some embodiments, the braking distance model includes a maximum braking force parameter. After the braking distance model of the target vehicle is updated based on the braking effect evaluation parameter to obtain an updated braking distance model, the vehicle braking distance detection method further includes: respectively obtaining the maximum braking force parameter and the updated maximum braking force parameter, wherein the updated maximum braking force parameter is obtained by updating the maximum braking force parameter based on the maximum braking force evaluation parameter; and updating the braking performance model based on the maximum braking force parameter and the updated maximum braking force parameter.

[0009] In some embodiments, the braking command information includes a braking command value, and the braking data information includes the speed information of the target vehicle. Based on the braking data information, the actual braking deceleration information of the target vehicle during the braking process is determined, including: during the braking process of the target vehicle, the timing starts when the current braking deceleration of the target vehicle is greater than the preset deceleration, and ends when the current speed of the target vehicle is less than the preset speed, or the current braking deceleration of the target vehicle is less than the preset deceleration; based on the speed information, the first speed of the target vehicle at the start of the timing and the second speed of the target vehicle at the end of the timing are determined respectively; based on the first speed, the second speed, and the timing duration, the actual braking deceleration information is determined; and / or, based on the braking performance model and the braking command information, the expected braking deceleration information is determined, including: based on the braking command information, at least one braking command value of the target vehicle during the timing process is determined; the average braking command value corresponding to the at least one braking command value is calculated; based on the average braking command value and the braking performance model, the expected braking deceleration information is determined.

[0010] In some embodiments, the braking distance model includes a maximum braking force parameter and a braking response delay parameter, and the braking effect evaluation parameter includes a maximum braking force evaluation parameter and / or a braking response delay evaluation parameter. Based on the braking effect evaluation parameter, the braking distance model of the target vehicle is updated to obtain an updated braking distance model, including: obtaining a learning rate parameter of the braking distance model; determining an updated maximum braking force parameter based on the learning rate parameter, the maximum braking force evaluation parameter, and the maximum braking force parameter; determining an updated braking distance model based on the updated maximum braking force parameter; and / or, determining an updated braking response delay parameter based on the learning rate parameter, the braking response delay evaluation parameter, and the braking response delay parameter; determining an updated braking distance model based on the updated braking response delay parameter. Optionally, determining an updated maximum braking force parameter based on the learning rate parameter, the maximum braking force evaluation parameter, and the maximum braking force parameter includes: determining a first maximum braking force parameter based on the maximum braking force evaluation parameter and the maximum braking force parameter; determining an updated maximum braking force parameter based on the first maximum braking force parameter, the learning rate parameter, and the maximum braking force parameter. Optionally, the braking distance model also includes at least one of the following: a vehicle mass parameter, a road surface slope parameter and a road surface rolling resistance coefficient parameter, and the braking distance is negatively correlated with the road surface rolling resistance coefficient parameter, and positively correlated with the road surface slope parameter and the vehicle mass parameter.

[0011] In some embodiments, the braking effect evaluation parameter includes a braking response delay evaluation parameter, and the braking data information includes the braking command information of the target vehicle during the braking process. Based on the braking data information, the actual braking effect of the target vehicle is evaluated to obtain the braking effect evaluation parameter, including: when the braking command information meets the slow deceleration condition, based on the braking distance model, the braking response delay parameter is obtained, and the braking response delay parameter is used as the braking response delay evaluation parameter, wherein the slow deceleration condition includes: the braking command value corresponding to the braking command information is greater than the first deceleration and less than the second deceleration, and the duration corresponding to the braking command information is greater than the preset duration; or, when the braking command information meets the non-slow deceleration condition, the braking response delay evaluation parameter is determined based on the braking data information, wherein the non-slow deceleration condition includes: at the beginning of the braking process, the braking command value corresponding to the braking command information is greater than the second deceleration. Optionally, when the braking command information meets the non-slow deceleration condition, a braking response delay evaluation parameter is determined based on the braking data information, including: determining the request time corresponding to the braking command information and the time when the target vehicle starts to decelerate based on the braking data information; and using the difference between the request time corresponding to the braking command information and the time when the target vehicle starts to decelerate as the braking response delay evaluation parameter.

[0012] In some embodiments, obtaining braking data information of a target vehicle during a braking process includes: obtaining first braking data information of the target vehicle, the first braking data information including first braking command information; when the first braking data information satisfies an update condition, determining that the first braking data information is braking data information; wherein the update condition includes at least one of the following: the target vehicle is in an unloaded state, the initial vehicle speed of the target vehicle is greater than a vehicle speed threshold, the braking command value corresponding to the first braking command information is greater than a deceleration threshold, the duration corresponding to the first braking command information is greater than a duration threshold, the absolute value of the slip rate of the target vehicle during braking is less than a slip rate threshold, and the slope of the road surface on which the target vehicle is located is within a preset slope range.

[0013] In a second aspect, a vehicle braking distance detection device is provided, comprising: an acquisition module, configured to acquire braking data information of a target vehicle during a braking process; an evaluation module, configured to evaluate an actual braking effect of the target vehicle based on the braking data information, and obtain a braking effect evaluation parameter; an update module, configured to update a braking distance model of the target vehicle based on the braking effect evaluation parameter, and obtain an updated braking distance model, wherein the braking distance model represents a functional relationship between a current vehicle speed and a braking distance of the target vehicle; and a determination module, configured to determine the braking distance of the target vehicle based on the updated braking distance model.

[0014] According to a third aspect, an electronic device is provided, comprising: a processor; and a memory for storing executable instructions of the processor; wherein the processor is configured to execute the method provided in the first aspect by executing the executable instructions.

[0015] According to a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the method provided in the first aspect is implemented.

[0016] The vehicle braking distance detection method provided by the present disclosure evaluates the actual braking effect of the braking system through the braking data information of the target vehicle during the braking process, and updates the braking distance model based on the evaluation result to correct the braking distance error caused by the attenuation of the braking performance. At the same time, since the braking data information is obtained based on the response characteristics of the target vehicle itself, the error caused by the different response characteristics between different vehicles of the same model can also be corrected. The accuracy of the braking distance detection can be improved through the updated braking distance model. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Shown is a schematic diagram of a scenario applicable to an embodiment of the present disclosure.

[0018] Figure 2The figure is a schematic flow chart of a method for detecting a vehicle braking distance provided in one embodiment of the present disclosure.

[0019] Figure 3 The figure is a flow chart of steps for evaluating the actual braking effect of a target vehicle based on braking data information and obtaining braking effect evaluation parameter information provided by an embodiment of the present disclosure.

[0020] Figure 4 The figure is a flow chart of the steps of determining the maximum braking force evaluation parameter based on the actual braking deceleration information and the braking command information of the target vehicle during the braking process provided by an embodiment of the present disclosure.

[0021] Figure 5 The figure is a flow chart of a method for constructing a braking performance model provided in one embodiment of the present disclosure.

[0022] Figure 6 Shown is a flow chart of a method for detecting a vehicle braking distance provided in another embodiment of the present disclosure.

[0023] Figure 7 The figure is a flow chart of the steps of determining the actual braking deceleration information of the target vehicle during the braking process based on the braking data information provided by an embodiment of the present disclosure.

[0024] Figure 8a The figure is a flow chart of the steps of updating the braking distance model of the target vehicle based on the braking effect evaluation parameters to obtain the updated braking distance model provided by an embodiment of the present disclosure.

[0025] Figure 8b The figure is a flowchart of the steps of updating the braking distance model of the target vehicle based on the braking effect evaluation parameters to obtain the updated braking distance model provided by another embodiment of the present disclosure.

[0026] Fig. 9 The figure is a flow chart of the steps of obtaining the braking data information of the target vehicle during the braking process provided by an embodiment of the present disclosure.

[0027] Fig.10 Shown is a schematic structural diagram of a vehicle braking distance detection device provided in an embodiment of the present disclosure.

[0028] Fig.11 Shown is a schematic structural diagram of an electronic device provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0030] Unmanned mining vehicles are an important part of smart mine construction. They use autonomous driving technology to achieve unmanned operation of mine transportation. Unmanned mining vehicles usually have a high degree of automation and can operate autonomously without human intervention in most environments.

[0031] In autonomous driving technology, braking distance refers to the distance a vehicle travels from the start of braking to when the vehicle comes to a complete stop when the vehicle is at a certain speed. It is one of the key parameters for measuring the braking performance of a vehicle. During the autonomous driving process, the vehicle needs to adjust its speed according to the speed and distance of the vehicle in front, which requires accurate calculation of the braking distance to maintain a sufficient safe distance. It can be seen that accurate vehicle braking distance plays a very important role in ensuring driving safety.

[0032] The braking distance of a vehicle is usually established based on a large amount of offline data, which requires a large amount of data collection and a high cost for establishing a braking distance model. In addition, all vehicles of the same model usually use the same braking distance model. However, mining vehicles have large manufacturing process deviations, and the response characteristics of the braking systems of different vehicles of the same model also vary to a certain extent. Therefore, the braking distance model is inaccurate for some vehicles of this model.

[0033] Secondly, since the establishment of the vehicle braking distance model is usually in the adaptation stage of new models, the collected data is collected when the vehicle braking system is in good condition. As the vehicle is used, the performance of the braking system will decay, especially for vehicles such as mining vehicles that need to perform material transportation tasks for a long time and have a relatively harsh driving environment. The braking distance model initially established is inaccurate for vehicles with decayed braking performance.

[0034] In addition, in the process of transporting materials by mining vehicles, the density differences of different loaded materials and the differences in loading standards of different projects lead to large differences in the fully loaded mass of mining vehicles. The fully loaded mass of the whole vehicle will affect the actual braking distance of the vehicle. The current braking distance model does not take into account the mass change of the vehicle when it is fully loaded or unloaded.

[0035] In view of the above technical problems, the present disclosure provides a method for detecting the braking distance of a vehicle, which obtains braking data information of a target vehicle during a braking process; based on the braking data information, an actual braking effect of the target vehicle is evaluated to obtain a braking effect evaluation parameter; based on the braking effect evaluation parameter, a braking distance model of the target vehicle is updated to obtain an updated braking distance model, wherein the braking distance model represents a functional relationship between the current speed of the target vehicle and the braking distance; and based on the updated braking distance model, the braking distance of the target vehicle is determined to improve the accuracy of vehicle braking distance detection.

[0036] Figure 1 FIG. 1 is a schematic diagram of a scenario applicable to an embodiment of the present disclosure. Figure 1 As shown, the scene is a mine scene, and the scene includes a vehicle. The vehicle includes a control system 110 and a braking system 120.

[0037] When the vehicle is driving on the mining road, it will adaptively adjust the current speed according to the surrounding environment. When the vehicle needs to slow down, the control system 110 generates a corresponding braking command, and the braking system 120 brakes the vehicle based on the braking command. During the braking process, the control system 110 collects corresponding braking data information. Based on the braking data information, the control system 110 adjusts the braking distance model of the vehicle through the vehicle braking distance detection method provided by the embodiment of the present disclosure, and determines the braking distance of the vehicle based on the braking distance model. Based on the braking distance, the vehicle's automatic driving functions such as emergency braking and adaptive following control can be realized.

[0038] When the vehicle decelerates again, the control system 110 collects the braking data information generated during the braking process, and uses the braking data information generated during this braking process to adjust the braking distance model again to obtain the braking distance of the vehicle. By continuously correcting the braking distance model of the target vehicle based on the braking data information of the target vehicle in actual use, a relatively accurate braking distance can be obtained throughout the life cycle of the target vehicle, providing key parameters for functions such as automatic emergency braking and adaptive vehicle following control, thereby improving the functional effects and safety of the target vehicle.

[0039] Combine the following Figures 2 to 9 An example is given to illustrate the method for detecting the braking distance of a vehicle provided in an embodiment of the present disclosure.

[0040] Figure 2 FIG. 2 is a flow chart of a method for detecting a vehicle braking distance provided by an embodiment of the present disclosure. Figure 2 As shown, the vehicle braking distance detection method provided in the embodiment of the present disclosure includes the following steps.

[0041] S210, obtaining braking data information of the target vehicle during the braking process.

[0042] The braking data information includes the braking command information of the target vehicle during the braking process, and the speed information of the target vehicle during the braking process, and the speed information includes the actual speed of the target vehicle at each moment during the braking process. The braking command information refers to the braking command requested by the control system of the target vehicle during the braking process, specifically including the braking command value corresponding to the braking command and the request time. In addition, the braking data information may also include the braking deceleration information of the target vehicle and other information that can reflect the braking effect of the vehicle. The above information may be collected by sensors carried by the target vehicle, or obtained by other methods, and the present disclosure does not impose specific restrictions on this.

[0043] A continuous braking process may include a plurality of braking command information, each of which includes a respective braking command value and a corresponding request time of the braking command information.

[0044] S220, based on the braking data information, evaluating the actual braking effect of the target vehicle to obtain a braking effect evaluation parameter.

[0045] The actual braking effect of the target vehicle is evaluated through the braking data information of the target vehicle during this braking process. The actual braking effect of the target vehicle can reflect the current performance of the braking system of the target vehicle. By comparing the current performance of the braking system with the initial performance or the performance at the previous moment, the braking effect evaluation parameter can be obtained. Among them, the braking effect evaluation parameter can reflect the attenuation of the braking performance of the target vehicle.

[0046] The performance of the braking system may include indicators such as braking intensity, braking response speed, braking stability, etc. Accordingly, there may be multiple braking effect evaluation parameters, and each of the multiple indicators corresponds to a different braking effect evaluation parameter.

[0047] Exemplarily, the actual response speed of the braking system to the braking command can be determined based on the braking data information, and the actual response speed can be compared with the response speed of the braking system in the initial state or at a previous moment to evaluate whether the braking response speed of the target vehicle has slowed down, and the evaluation result can be used as a braking effect evaluation parameter for evaluating the response speed.

[0048] Exemplarily, the actual braking strength of the braking system can be determined based on the braking data information, and the actual braking strength can be compared with the braking strength requested by the braking instruction to evaluate whether the braking strength of the target vehicle has decayed compared to the initial state or the state at a previous moment, and the evaluation result can be used as a braking effect evaluation parameter for evaluating the braking strength.

[0049] S230, updating the braking distance model of the target vehicle based on the braking effect evaluation parameter to obtain an updated braking distance model.

[0050] The braking distance model represents the functional relationship between the current speed of the target vehicle and the braking distance.

[0051] The initial braking distance model of the target vehicle is established based on the initial response characteristics of the braking system of the target vehicle. As the target vehicle works, the braking performance of the target vehicle gradually decays, and the initial braking distance model can no longer accurately obtain the braking distance of the target vehicle.

[0052] The braking effect evaluation parameter can reflect the braking performance attenuation of the target vehicle. Therefore, the braking distance model of the target vehicle can be updated based on the braking effect evaluation parameter to obtain an updated braking distance model.

[0053] For example, when the braking performance attenuation of the target vehicle is determined based on the braking effect evaluation parameter, the actual braking distance required by the target vehicle becomes longer than the expected braking distance, which means that in an emergency, the target vehicle may not be able to stop within the expected distance. Among them, the expected braking distance of the target vehicle can be determined by an unupdated braking distance model. At this time, the functional relationship between the current vehicle speed and the braking distance in the braking distance model can be appropriately adjusted to obtain an updated braking distance model. In the updated braking distance model, the same current vehicle speed corresponds to a larger braking distance.

[0054] When it is determined based on the braking effect evaluation parameter that the braking performance of the target vehicle has not been attenuated, the non-updated braking distance model may continue to be used until the braking performance of the target vehicle is attenuated.

[0055] It is understandable that the above-mentioned unupdated braking distance model can be the initial braking distance model of the target vehicle, or it can be the braking distance model of the target vehicle obtained by updating at the previous moment. Exemplarily, at the first moment, the braking distance model of the target vehicle is updated to obtain the braking distance model corresponding to the first moment. At the second moment after the first moment, the target vehicle determines that the braking performance is attenuated compared to the first moment based on the braking effect evaluation parameter. At this time, the braking distance model corresponding to the first moment can be used as the unupdated braking distance model, and then the braking distance model corresponding to the first moment is updated to obtain the braking distance model corresponding to the second moment (i.e., the updated braking distance model). In this way, the braking distance model of the target vehicle is continuously corrected through updating and iteration to ensure the accuracy of the braking distance model of the target vehicle throughout its life cycle.

[0056] S240: Determine a braking distance of the target vehicle based on the updated braking distance model.

[0057] The updated braking distance model can accurately reflect the functional relationship between the current speed and braking distance of the target vehicle. Therefore, during driving, when the automatic emergency braking function, adaptive vehicle following control function and other functions of the target vehicle require braking distance as a parameter, the braking distance of the target vehicle can be obtained based on the real-time current speed of the target vehicle and the updated braking distance model.

[0058] In the disclosed embodiment, the actual braking effect of the braking system is evaluated through the braking data information of the target vehicle during the braking process, and the braking distance model is updated based on the evaluation result to correct the braking distance error caused by the attenuation of the braking performance. At the same time, since the braking data information is obtained based on the response characteristics of the target vehicle itself, the error caused by the different response characteristics between different vehicles of the same model can also be corrected. The accuracy of the braking distance detection can be improved through the updated braking distance model.

[0059] The following first introduces a method for establishing an initial braking distance model in an embodiment of the present disclosure.

[0060] Analysis of the target vehicle's braking process shows that the target vehicle's braking distance is related to the vehicle mass, the road slope parameter of the target vehicle, the road rolling resistance coefficient parameter, the current vehicle speed, and the target vehicle's initial maximum braking force parameter. At the same time, considering the response delay of the braking system, the target vehicle's braking distance is also affected by the initial braking response delay parameter; the braking response delay parameter refers to the time from when the control system issues a braking command to when the target vehicle actually starts to decelerate.

[0061] The analysis shows that the braking distance of the target vehicle is negatively correlated with the road rolling resistance coefficient parameter and the initial maximum braking force parameter, and positively correlated with the road slope parameter, vehicle mass parameter, current vehicle speed, and initial braking response delay parameter. Based on the above relationships, the following initial braking distance model expression can be established:

[0062]

[0063] Where S represents the braking distance; m represents the vehicle mass parameter; F xmax0 represents the initial maximum braking force parameter; g represents the acceleration of gravity; θ represents the road slope parameter; f represents the road rolling resistance coefficient parameter; v x Indicates the current vehicle speed; t0 indicates the initial braking response delay parameter.

[0064] The vehicle mass parameter refers to the vehicle mass of the target vehicle, that is, when the target vehicle is running unloaded, the vehicle mass parameter is the actual measured mass of the target vehicle when it leaves the factory; when the target vehicle is running loaded, the vehicle mass parameter is the vehicle mass obtained using a weighing system.

[0065] The following will continue to introduce the method for determining the initial maximum braking force parameters.

[0066] The target vehicle is driven unloaded on a flat first road surface to a maximum speed v0, and then the throttle request is immediately cleared without braking, so that the target vehicle coasts to a stop, and the coasting time t of the target vehicle from the start of coasting to the stop is recorded. h According to the sliding time t h And the maximum vehicle speed v0 can determine the road rolling resistance coefficient of the first road surface Here, θ0 represents the average slope value of the first road surface.

[0067] Next, the target vehicle is driven unloaded on the flat second road surface to a maximum speed v0, and then the maximum braking deceleration is immediately requested and maintained until the target vehicle stops. The deceleration time t of the target vehicle from the start of braking to the stop is recorded. j The difference between the time when the maximum braking deceleration is requested and the time when braking begins is taken as the initial braking response delay parameter t0. Based on the above parameters, the initial maximum braking force parameter is calculated. Wherein, θ1 represents the average slope value of the second road surface, and m1 represents the vehicle mass of the target vehicle in an unloaded state. The first road surface and the second road surface may be the same road surface.

[0068] In some embodiments, since the road rolling resistance coefficient parameter is difficult to determine in real time, the road rolling resistance coefficient parameter can be set to a fixed value to simplify the calculation difficulty. For example, the road rolling resistance coefficient parameter can use the road rolling resistance coefficient f0 of the first road surface obtained in the above steps.

[0069] At this point, the initial braking distance model can be written as:

[0070]

[0071] Alternatively, if the road surface in the operating environment of the target vehicle is relatively flat, the road surface slope parameter can also be set to a fixed value. Exemplarily, the road surface slope parameter can use the average slope value of the first road surface or the second road surface obtained in the above steps. Alternatively, if the target vehicle does not undertake the task of material transportation, the vehicle mass parameter can also be set to a fixed value. In summary, optionally, the parameters of the braking distance model of the target vehicle include at least one of the following: vehicle mass parameter, road surface slope parameter and road surface rolling resistance coefficient parameter. The braking distance is negatively correlated with the road surface rolling resistance coefficient parameter, and positively correlated with the road surface slope parameter and the vehicle mass parameter.

[0072] It is understandable that the target vehicle in this embodiment can actually be another vehicle of the same model as the target vehicle. Although there may be a certain error between the braking distance model established in this way and the actual response characteristics of the target vehicle, this error can be corrected by updating the braking distance model during driving. In this way, the cost of determining the braking distance model can be reduced.

[0073] The following will continue to introduce the specific implementation method of determining the braking effect evaluation parameters based on the braking data information.

[0074] In this embodiment, the braking effect evaluation parameter includes a maximum braking force evaluation parameter and / or a braking response delay evaluation parameter. The maximum braking force evaluation parameter is used to evaluate the actual braking strength of the target vehicle. The braking response delay evaluation parameter is used to evaluate the actual braking response speed of the target vehicle. The following describes the determination methods of the maximum braking force evaluation parameter and the braking response delay evaluation parameter.

[0075] like Figure 3 As shown, based on the braking data information, the actual braking effect of the target vehicle is evaluated, and the step of obtaining the braking effect evaluation parameter specifically includes the following steps.

[0076] S221, determining actual braking deceleration information of the target vehicle during braking based on the braking data information.

[0077] The actual braking deceleration information refers to the average braking deceleration of the target vehicle over a period of time during the braking process.

[0078] For example, the braking data information includes the speed information of the target vehicle during the braking process, and the actual braking deceleration information can be calculated by combining the speed information within a period of time with the duration of the period of time. Alternatively, the braking data information includes the deceleration information of the target vehicle during the braking process, in which case the average value of the deceleration within a period of time can be directly used as the actual braking deceleration information.

[0079] S222: Determine a maximum braking force evaluation parameter based on actual braking deceleration information and braking command information of the target vehicle during braking.

[0080] It is understandable that the braking strength of the target vehicle is closely related to its maximum braking force. When the braking strength decays, it means that the current maximum braking force of the braking system is lower than the previous moment. The maximum braking force evaluation parameter can actually reflect whether the maximum braking force of the target vehicle has decayed.

[0081] Since there is a direct relationship between the braking deceleration and the braking force of the target vehicle, as an implementation method, the deceleration requested by the braking command (i.e., the braking command value corresponding to the braking command) can be compared with the actual deceleration of the target vehicle during the braking process to obtain a comparison result. For example, the comparison result can be the difference between the braking command value and the actual braking deceleration information, or it can also be the ratio of the braking command value to the actual braking deceleration information.

[0082] Based on the comparison result, it can be determined whether the braking strength of the target vehicle has been attenuated compared to the initial state or the state at the previous moment. Therefore, the comparison result can be used as the maximum braking force evaluation parameter.

[0083] S223: Determine a braking response delay evaluation parameter based on the braking data information.

[0084] The brake response delay parameter can directly reflect the brake response speed of the brake system to the brake command. Therefore, by comparing the actual brake response delay parameter at the current moment with the brake response delay parameter of the brake system in the initial state or at the previous moment, it can be determined whether the brake system performance has been degraded.

[0085] The actual braking response delay parameter can be determined based on the braking command information and the vehicle speed information in the braking data information. Specifically, the actual braking response delay parameter can be determined by the request time corresponding to the braking command information and the time when the target vehicle actually starts to decelerate, and the time when the target vehicle actually starts to decelerate can be determined by the vehicle speed information.

[0086] After determining the actual braking response delay parameter based on the braking data information, the braking response delay evaluation parameter can be determined based on the actual braking response delay parameter. For example, the actual braking response delay parameter can be directly used as the braking response delay evaluation parameter to intuitively reflect the braking response speed of the braking system to the braking command. Alternatively, the difference or ratio between the actual braking response delay parameter at the current moment and the braking response delay parameter at the previous moment can be used as the braking response delay evaluation parameter, and the changes of the two can be used to determine whether the braking response speed has changed.

[0087] In the disclosed embodiment, the determination method of the maximum braking force evaluation parameter and the braking response delay evaluation parameter is introduced. The maximum braking force evaluation parameter and the braking response delay evaluation parameter evaluate whether the braking performance of the braking system is attenuated from the aspects of braking intensity and braking response speed respectively. This provides a multi-dimensional reference for the subsequent update of the braking distance model.

[0088] Next, a specific implementation method for determining the maximum braking force evaluation parameter is described. Figure 4 As shown, the step of determining the maximum braking force evaluation parameter based on the actual braking deceleration information and the braking command information of the target vehicle during the braking process provided by the embodiment of the present disclosure includes the following steps.

[0089] S2221, obtaining a braking performance model of the target vehicle.

[0090] The braking performance model represents the functional relationship between the braking command value corresponding to the braking command information and the expected braking deceleration. The expected braking deceleration represents the magnitude of the braking deceleration that the control system actually expects the braking system to generate when the control system issues the braking command information.

[0091] In the embodiment of the present disclosure, the braking performance model is denoted as a m =g1(a a ), where a a Indicates the braking command value, a m represents the expected braking deceleration (i.e. the expected braking deceleration information described below), and g1(·) represents the functional relationship between the two. m When the brake system is requested to a The braking command value.

[0092] S2222: Determine expected braking deceleration information based on the braking performance model and the braking command information.

[0093] The braking deceleration that the control system actually expects the braking system to generate, ie, the expected braking deceleration information, can be determined through the braking performance model and the braking command value corresponding to the braking command information.

[0094] For example, the braking command value corresponding to the braking command information is a a1 , a a1 As the independent variable of the braking performance model, the expected braking deceleration information a corresponding to the braking command value is obtained. m1 =g1(a a1 ).

[0095] S2223: Determine a maximum braking force evaluation parameter based on the expected braking deceleration information and the actual braking deceleration information.

[0096] The braking performance model is determined before the braking process occurs, so the braking performance reflected by the braking performance model is actually the braking performance at the previous moment of the braking process. If the braking performance of the target vehicle has not been attenuated compared to the previous moment, the actual braking deceleration information should be consistent with the expected braking deceleration information.

[0097] When the actual braking deceleration information is inconsistent with the expected braking deceleration information, it means that the braking performance model can no longer accurately reflect the actual braking performance of the target vehicle, and the maximum braking force of the braking system at the current moment has decayed compared to the moment described by the braking performance model. Therefore, the maximum braking force evaluation parameter can be determined based on the gap between the expected braking deceleration information and the actual braking deceleration information, so as to evaluate the degree of decay of the braking performance based on the maximum braking force evaluation parameter.

[0098] Optionally, the ratio of the actual braking deceleration information to the expected braking deceleration information can be used as the maximum braking force evaluation parameter, denoted as Among them, a r Indicates the actual braking deceleration information, a m Indicates expected braking deceleration information.

[0099] In the disclosed embodiment, by comparing the response of the braking system to the braking command during the current braking process with the response at the previous moment, it is determined whether the maximum braking force of the braking system has decayed. In addition, based on the expected braking deceleration information and the actual braking deceleration information, the decay of the maximum braking force can be quantified, providing a basis for the subsequent update of the braking distance model.

[0100] The following is an introduction to the construction method of the initial braking performance model. Figure 5 As shown, the method for constructing the braking performance model includes the following steps.

[0101] S510: When the target vehicle is traveling at the maximum vehicle speed, a plurality of braking instructions are requested respectively.

[0102] The braking command values ​​corresponding to the multiple braking commands are different. For example, four braking commands may be requested respectively, and the braking command values ​​corresponding to the four braking commands are 0.4a and 0.5a, respectively. max , 0.6a max , 0.8a max 、a max , where g max Indicates the maximum braking command value of the target vehicle. When the maximum braking command value of the target vehicle is requested, the actual braking force generated by the brake system should be the maximum braking force of the target vehicle.

[0103] The braking process of each request for a braking command is independent of each other, that is, before each request for a braking command, it is necessary to ensure that the target vehicle is traveling at the maximum speed.

[0104] S520: For each braking instruction, determine an actual deceleration value of the target vehicle under the braking instruction.

[0105] After requesting a braking command, an actual deceleration value of the target vehicle under the braking command is determined.

[0106] Exemplarily, a braking command may be requested and maintained until the target vehicle stops, the duration of the braking process is determined, and based on the duration of the braking process and the maximum speed of the target vehicle, the actual deceleration value corresponding to the braking command may be calculated.

[0107] Through the above method, the actual deceleration values ​​corresponding to the multiple braking instructions can be calculated respectively.

[0108] S530: construct a braking performance model based on the braking command values ​​corresponding to the plurality of braking commands and the actual deceleration values ​​corresponding to the plurality of braking commands.

[0109] The braking instruction values ​​and actual deceleration values ​​corresponding to the multiple braking instructions are fitted to obtain a braking performance model.

[0110] For example, taking the four braking instructions in the above steps as an example, the actual deceleration values ​​corresponding to the four braking instructions are a1, a2, a3, and a4, respectively. On this basis, a corresponding relationship between the braking instruction value and the actual deceleration value can be established. Furthermore, a corresponding relationship between the braking instruction value, the actual deceleration value, and the actual braking force generated by the braking system can also be established, as shown in Table 1.

[0111] Table 1

[0112]

[0113] in, are the actual braking forces corresponding to the four braking commands; b4=1, The braking performance model is usually established during the adaptation stage of a new vehicle model. At this time, the actual braking force corresponding to the maximum braking command value can directly use the initial maximum braking force parameter F of the target vehicle. xmax0 .

[0114] Based on the corresponding relationship between the braking command value and the actual deceleration value listed in Table 1, the initial braking performance model a is obtained by fitting the linear interpolation method. m =g0(a a ).

[0115] It is understandable that during the initial construction of the braking performance model, the braking performance of the target vehicle has not yet decayed, and the actual deceleration value in this embodiment is consistent with the braking deceleration actually expected by the control system. However, as the target vehicle travels, the braking performance of the target vehicle gradually decays, and at this time, the braking performance model of the target vehicle needs to be adjusted in a timely manner according to the decay of the braking performance. An implementation method for updating the braking performance model is described below.

[0116] like Figure 6 As shown, after the braking distance model of the target vehicle is updated based on the braking effect evaluation parameter to obtain the updated braking distance model, the vehicle braking distance detection method provided by the embodiment of the present disclosure further includes the following steps.

[0117] S610, respectively obtaining a maximum braking force parameter and an updated maximum braking force parameter.

[0118] The braking distance model of the target vehicle includes a maximum braking force parameter, so the maximum braking force parameter can be obtained through the braking distance model. Specifically, the maximum braking force parameter in this embodiment is the maximum braking force parameter included in the unupdated braking distance model, and the updated maximum braking force parameter is the maximum braking force parameter included in the updated braking distance model.

[0119] The updated maximum braking force parameter is obtained by updating the maximum braking force parameter based on the maximum braking force evaluation parameter. The maximum braking force evaluation parameter can reflect the attenuation of the maximum braking force of the target vehicle, so the updated maximum braking force parameter can be determined based on the maximum braking force evaluation parameter and the maximum braking force parameter in the unupdated braking distance model.

[0120] S620: Update the braking performance model based on the maximum braking force parameter and the updated maximum braking force parameter.

[0121] The braking performance model is a linear function with the braking command value as the independent variable and the expected braking deceleration as the dependent variable. Therefore, based on the proportional relationship between the maximum braking force parameter and the updated maximum braking force parameter, the coefficient of the braking command value in the braking performance model can be adjusted to achieve the update of the braking performance model and obtain the updated braking performance model.

[0122] For example, the symbols in the above embodiment are continued to be used, and the unupdated braking distance model is denoted as a m =g1(a a ), the maximum braking force parameter is recorded as F xmax (k―1); the updated maximum braking force parameter is recorded as F xmax(k) At this time, a corresponding relationship between the target vehicle's braking command value, the actual deceleration value, and the actual braking force generated by the braking system can be established, as shown in Table 2.

[0123] Table 2

[0124]

[0125] Where d represents the learning rate of the update process, and its value range is [0,1]. The specific value of d can be set according to the actual situation.

[0126] Through the above correspondence, the functional relationship g2(·) between the braking command value and the actual deceleration value can be established. Since we expect the updated braking performance model to truly reflect the actual braking performance of the target vehicle at the current moment, the functional relationship between the braking command value and the expected braking deceleration in the updated braking performance model should be consistent with the functional relationship between the braking command value and the actual deceleration value established above. The updated braking performance model is a m =g2(a a ).

[0127] In the disclosed embodiment, after the braking performance of the braking system is detected to have decayed, the braking performance model can be adjusted in a timely manner according to the maximum braking force evaluation parameter, so that the control system can adaptively adjust the control strategy based on the updated braking performance model and issue appropriate braking instructions during the subsequent driving process. This also provides a basis for updating the braking distance model during the subsequent driving process, so that a relatively accurate braking distance can be obtained throughout the life cycle of the target vehicle.

[0128] The above specifically introduces the construction method and update method of the braking performance model, and the following continues to introduce a method for determining actual braking deceleration information. In the embodiment of the present disclosure, the braking command information includes a braking command value, and the braking data information includes the speed information of the target vehicle.

[0129] like Figure 7 As shown, based on the braking data information, the step of determining the actual braking deceleration information of the target vehicle during the braking process specifically includes the following steps.

[0130] S2211, during the braking process of the target vehicle, the timing starts when the current braking deceleration of the target vehicle is greater than the preset deceleration, and ends when the current speed of the target vehicle is less than the preset speed, or the current braking deceleration of the target vehicle is less than the preset deceleration.

[0131] The preset deceleration rate can be set according to the actual situation. For example, it can be set to 0.4a. maxThe preset vehicle speed can also be set according to actual conditions, and for example, can be set to 1 km / h.

[0132] When the current braking deceleration of the target vehicle is greater than the preset deceleration, the timing starts, and the timing start time is recorded as t s When the current speed of the target vehicle is less than the preset speed, or the current braking deceleration of the target vehicle is less than the preset deceleration, the timing ends, and the timing end time is recorded as t e .

[0133] The timing start time and the timing end time are both a certain moment in the braking process.

[0134] S2212: Based on the vehicle speed information, determine a first vehicle speed of the target vehicle at the start time of timing and a second vehicle speed of the target vehicle at the end time of timing.

[0135] Based on the vehicle speed information, it is possible to determine the target vehicle at the timing start time t s The first speed v s , and at the end time t e The second speed v e , the time interval from the start time to the end time is t c =t s ―t e .

[0136] S2213: Determine actual braking deceleration information based on the first vehicle speed, the second vehicle speed, and the timing duration.

[0137] The actual braking deceleration information of the target vehicle can be calculated from the above parameters

[0138] In the disclosed embodiment, by setting the start and end conditions of the timing, the actual braking deceleration information can more accurately reflect the actual deceleration of the target vehicle during the timing process, avoiding measurement errors caused by excessive deceleration, and improving the accuracy of the actual braking deceleration information.

[0139] In this case, the braking command information should also be the braking command requested by the control system during the timing process. Optionally, based on the braking performance model and the braking command information, the step of determining the expected braking deceleration information specifically includes: determining at least one braking command value of the target vehicle during the timing process based on the braking command information; calculating the average braking command value corresponding to the at least one braking command value; and determining the expected braking deceleration information based on the average braking command value and the braking performance model.

[0140] After the average braking command value is determined, the average braking command value is used as an independent variable of the braking performance model to obtain the expected braking deceleration information during the timing process.

[0141] Next, a specific implementation method of updating the braking distance model based on the braking effect evaluation parameter is introduced. In the disclosed embodiment, the braking distance model includes a maximum braking force parameter and a braking response delay parameter, and the braking effect evaluation parameter includes a maximum braking force evaluation parameter and / or a braking response delay evaluation parameter.

[0142] like Figure 8a As shown, based on the braking effect evaluation parameter, the braking distance model of the target vehicle is updated to obtain the updated braking distance model, which specifically includes the following steps.

[0143] S231, obtaining a learning rate parameter of a braking distance model.

[0144] The learning rate parameter can be set according to the actual situation. When the update frequency of the braking distance model is high, a smaller learning rate parameter can be set accordingly; when the update frequency is low, a larger learning rate parameter can be set accordingly. That is, the learning rate parameter can be set according to the update frequency of the braking distance model.

[0145] For the convenience of description, the learning rate parameter is recorded as d here. However, it can be understood that the value of the learning rate parameter in this embodiment can be the same as or different from the value of the learning rate in the above embodiment, and the present disclosure does not make any specific limitation on this.

[0146] S232: Determine an updated maximum braking force parameter based on the learning rate parameter, the maximum braking force evaluation parameter, and the maximum braking force parameter.

[0147] The unupdated braking distance model at this time is determined before the current braking process occurs, so the maximum braking force parameter in the braking distance model is actually the maximum braking force parameter at the previous moment of the current braking process, denoted as F xmax (k―1).

[0148] After determining that the maximum braking force of the target vehicle is attenuated based on the maximum braking force evaluation parameter, the previously unupdated maximum braking force parameter can be updated based on the learning rate parameter and the maximum braking force evaluation parameter to obtain an updated maximum braking force parameter.

[0149] Optionally, based on the learning rate parameter, the maximum braking force evaluation parameter, and the maximum braking force parameter, the step of determining the updated maximum braking force parameter specifically includes the following steps.

[0150] First, based on the maximum braking force evaluation parameters And the maximum braking force parameter Fxmax (k―1), determine the first maximum braking force parameter

[0151] Next, based on the first maximum braking force parameter Learning rate parameter d and maximum braking force parameter F xmax (k―1), determine the updated maximum braking force parameter

[0152] S233: Determine an updated braking distance model based on the updated maximum braking force parameter.

[0153] After the updated maximum braking force parameter is determined, the maximum braking force parameter in the braking distance model may be directly replaced with the updated maximum braking force parameter to obtain an updated braking distance model.

[0154] Exemplarily, the unupdated braking distance model is The maximum braking force parameter F xmax (k―1) is replaced by the updated maximum braking force parameter F xmax (k), get the updated braking distance model Wherein, t represents the braking response delay parameter.

[0155] The above describes the updating method of the maximum braking force parameter in the braking distance model. The following describes the updating method of the braking response delay parameter in the braking distance model. Figure 8b As shown, based on the braking effect evaluation parameter, the braking distance model of the target vehicle is updated to obtain the updated braking distance model, and the step also includes the following steps.

[0156] S231, obtaining a learning rate parameter of a braking distance model.

[0157] It can be understood that the value of the learning rate parameter in this step may be the same as or different from the learning rate parameter or the learning rate value in the previous step; for the convenience of description, the learning rate parameter is denoted as d here.

[0158] S234: Determine an updated braking response delay parameter based on the learning rate parameter, the braking response delay evaluation parameter, and the braking response delay parameter.

[0159] The braking response delay parameter in the unupdated braking distance model is recorded as t(k-1).

[0160] In the above embodiments, various expressions of the brake response delay evaluation parameter are introduced. In this embodiment, the actual brake response delay parameter of the target vehicle at the current moment is directly used as the expression of the brake response delay evaluation parameter. Here, the brake response delay evaluation parameter is recorded as t1.

[0161] Based on the learning rate parameter d, the brake response delay evaluation parameter t1, and the brake response delay parameter t(k−1), an updated brake response delay parameter t(k)=(1−d)t(k−1)+dt1 can be obtained.

[0162] It can be understood that if the brake response delay evaluation parameter is in other forms, the updated brake response delay parameter can also be obtained in a similar manner, which will not be described in detail here.

[0163] S235: Determine an updated braking distance model based on the updated braking response delay parameter.

[0164] After the updated braking response delay parameter is determined, the braking response delay parameter in the braking distance model may be directly replaced with the updated braking response delay parameter to obtain an updated braking distance model.

[0165] Exemplarily, the unupdated braking distance model is The braking response delay parameter t(k-1) is replaced with the updated braking response delay parameter t(k) to obtain the updated braking distance model. Among them, F xmax Indicates the maximum braking force parameter.

[0166] In the disclosed embodiment, a method for updating the braking distance model based on the braking effect evaluation parameter is introduced. The update amplitude of the braking distance model can be adjusted through the learning rate parameter, and the learning rate parameter can also be adaptively changed according to the update frequency of the braking distance model, thereby improving the intelligence of the update process and the stability and accuracy of the braking distance model throughout the life cycle of the target vehicle.

[0167] It is understandable that the updating process of the maximum braking force parameter and the braking response delay parameter are independent of each other. The updating order of the maximum braking force parameter and the braking response delay parameter can be interchanged, or only the maximum braking force parameter or the braking response delay parameter can be updated.

[0168] For example, during the slow deceleration of the target vehicle, the actual braking response delay parameter determined is not accurate. In this case, only the maximum braking force parameter in the braking distance model may be updated, and the braking response delay parameter is not updated.

[0169] In some embodiments, based on the braking data information, the actual braking effect of the target vehicle is evaluated to obtain a braking effect evaluation parameter step, including: when the braking command information meets the slow deceleration condition, based on the braking distance model, obtaining a braking response delay parameter, and using the braking response delay parameter as a braking response delay evaluation parameter. In the disclosed embodiment, the braking effect evaluation parameter includes a braking response delay evaluation parameter, and the braking data information includes braking command information of the target vehicle during braking.

[0170] Specifically, when the braking command information satisfies the slow deceleration condition, the braking response delay parameter t(k-1) at the previous moment is directly used as the braking response delay evaluation parameter t1. Based on the calculation method of the updated braking response delay parameter introduced in the above embodiment, the updated braking response delay parameter t(k)=t(k-1) is obtained. Alternatively, it can be simply understood that when the braking command information satisfies the slow deceleration condition, the braking response delay parameter at the previous moment is directly used without updating the braking response delay parameter.

[0171] The slow deceleration condition includes: a braking command value corresponding to the braking command information is greater than the first deceleration and less than the second deceleration, and a duration corresponding to the braking command information is greater than a preset duration.

[0172] The first deceleration, the second deceleration, and the preset duration can be set according to actual conditions. For example, the first deceleration can be set to 0.2a. max , the second deceleration can be set to 0.4a max , the preset time can be set to 0.5 seconds. That is, when the braking command value is changed from 0.2a max Change to 0.4a max If the braking process is longer than 0.5 seconds, it is determined that the current braking process is a slow deceleration process.

[0173] In other embodiments, the actual braking effect of the target vehicle is evaluated based on the braking data information to obtain the braking effect evaluation parameter step, which also includes: when the braking command information meets the non-slow deceleration condition, determining the braking response delay evaluation parameter based on the braking data information.

[0174] Specifically, when the braking command information satisfies the non-slow deceleration condition, the actual braking response delay parameter of the target vehicle at the current moment can be determined based on the braking data information, and the braking response delay evaluation parameter can be determined based on the actual braking response delay parameter.

[0175] The non-slow deceleration condition includes: at the start of the braking process, the braking command value corresponding to the braking command information is greater than the second deceleration. If the braking command information satisfies the non-slow deceleration condition, it means that the control system requested a larger deceleration at the start of the braking process, and the actual braking response delay parameter determined based on the braking data information is relatively accurate.

[0176] Optionally, when the braking command information satisfies the non-slow deceleration condition, the step of determining the braking response delay evaluation parameter based on the braking data information includes: determining the request time corresponding to the braking command information and the time when the target vehicle starts to decelerate based on the braking data information; and using the difference between the request time corresponding to the braking command information and the time when the target vehicle starts to decelerate as the braking response delay evaluation parameter.

[0177] In the disclosed embodiment, whether the current braking process of the target vehicle is a slow deceleration process is determined through non-slow deceleration conditions and slow deceleration conditions, so as to determine whether the braking response delay parameter in the braking distance model is updated, thereby improving the accuracy of the braking distance model.

[0178] In the above embodiments, the updating of the braking distance model and the detection of the vehicle braking distance are both performed based on the braking data information. The reliability of the braking data information greatly affects the accuracy of the vehicle braking distance detection. Therefore, the braking data information needs to be screened.

[0179] like Fig. 9 As shown, the step of obtaining the braking data information of the target vehicle during the braking process specifically includes the following steps.

[0180] S211, obtaining first braking data information of the target vehicle.

[0181] The first braking data information is braking data information of the target vehicle in any braking process, wherein the first braking data information includes first braking command information, and the first braking command information is braking command information in the braking process.

[0182] S212: When the first braking data information meets an update condition, determine that the first braking data information is braking data information.

[0183] Next, the first braking data information needs to be screened, and the first braking data information that meets the update condition is used as the braking data information that can be used to update the braking distance model.

[0184] Specifically, the update conditions include at least one of the following: the target vehicle is in an unloaded state, the initial vehicle speed of the target vehicle is greater than a speed threshold, the braking command value corresponding to the first braking command information is greater than a deceleration threshold, the duration corresponding to the first braking command information is greater than a duration threshold, the absolute value of the slip rate of the target vehicle during braking is less than a slip rate threshold, and the slope of the road surface where the target vehicle is located is within a preset slope range.

[0185] Among them, the speed threshold, deceleration threshold, duration threshold, slip rate threshold, and preset slope range are all parameters that can be set according to actual conditions, and the present disclosure does not impose specific restrictions on this. For example, the speed threshold can be set to 10 km / h, the slip rate threshold can be set to 0.2, the preset slope range can be set to [-1.5 deg, 1.5 deg], the duration threshold can be set to 2 seconds, and the deceleration threshold can be set to 0.4a max .

[0186] When the first braking data information meets the above-mentioned updating conditions, it indicates that the braking process is less affected by the external environment or the vehicle's own weight, and the collected data is relatively reliable.

[0187] In the disclosed embodiment, the braking data information is screened by updating conditions, thereby improving the quality and reliability of the braking data information, thereby improving the accuracy of vehicle braking distance detection.

[0188] Combination of the above Figures 1 to 9 The method embodiment of the present disclosure is described in detail. Fig.10 The device embodiment of the present disclosure is described in detail. It should be understood that the description of the method embodiment corresponds to the description of the device embodiment, so the parts not described in detail can refer to the previous method embodiment.

[0189] Fig.10 FIG. 1 is a schematic diagram of the structure of a vehicle braking distance detection device provided by an embodiment of the present disclosure. Fig.10 As shown, the vehicle braking distance detection device 1000 of the embodiment of the present disclosure includes: an acquisition module 1010, an evaluation module 1020, an update module 1030, and a determination module 1040.

[0190] Specifically, the acquisition module 1010 is configured to acquire the braking data information of the target vehicle during the braking process. The evaluation module 1020 is configured to evaluate the actual braking effect of the target vehicle based on the braking data information to obtain a braking effect evaluation parameter. The update module 1030 is configured to update the braking distance model of the target vehicle based on the braking effect evaluation parameter to obtain an updated braking distance model, wherein the braking distance model represents the functional relationship between the current speed of the target vehicle and the braking distance. The determination module 1040 is configured to determine the braking distance of the target vehicle based on the updated braking distance model.

[0191] In some embodiments, the vehicle braking distance detection device 1000 also includes a braking performance model updating module, which is configured to respectively obtain a maximum braking force parameter and an updated maximum braking force parameter, wherein the updated maximum braking force parameter is obtained by updating the maximum braking force parameter based on a maximum braking force evaluation parameter; and the braking performance model is updated based on the maximum braking force parameter and the updated maximum braking force parameter.

[0192] Below, reference Fig.11 An electronic device according to an embodiment of the present disclosure is described. Fig.11 FIG. 1 is a schematic diagram of the structure of an electronic device provided by an exemplary embodiment of the present disclosure. Fig.11 As shown, electronic device 1100 includes one or more processors 1110 and memory 1120 .

[0193] The processor 1110 may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device 1100 to perform desired functions.

[0194] The memory 1120 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. Volatile memory may include, for example, random access memory (RAM) and / or cache memory (cache), etc. Non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 1110 may execute the program instructions to implement the vehicle braking distance detection method of each embodiment of the present disclosure described above and / or other desired functions.

[0195] In some embodiments, the electronic device 1100 may further include: an input device 1130 and an output device 1140 , and these components are interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0196] The input device 1130 may include, for example, a touch screen, a microphone, a keyboard, a mouse, etc. The output device 1140 may include, for example, a display, a speaker, a communication network and a remote output device connected thereto.

[0197] Of course, to simplify, Fig.11 Only some of the components related to the present disclosure in the electronic device 1100 are shown, and components such as a bus, an input / output interface, etc. are omitted. In addition, according to specific application scenarios, the electronic device 1100 may also include any other appropriate components.

[0198] In addition to the above-mentioned methods and devices, an embodiment of the present disclosure may also be a computer program product, which includes computer program instructions, which, when executed by a processor, enable the processor to execute the steps of the vehicle braking distance detection method according to various embodiments of the present disclosure described above in this specification.

[0199] The computer program product may be written in any combination of one or more programming languages ​​to write program code for performing the operations of the disclosed embodiments, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0200] In addition, an embodiment of the present disclosure may also be a computer-readable storage medium having computer program instructions stored thereon, which, when executed by a processor, enables the processor to execute the steps of the vehicle braking distance detection method according to various embodiments of the present disclosure described above in this specification.

[0201] Computer readable storage media can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can include, for example, but is not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0202] The basic principles of the present disclosure are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present disclosure are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present disclosure. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, and are not limitations. The above details do not limit the present disclosure to the necessity of adopting the above specific details to be implemented.

[0203] The block diagrams of the devices, apparatuses, equipment, and systems involved in this disclosure are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including," "comprising," "having," and the like are open words, referring to "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or," and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0204] It should also be noted that in the system, device and method of the present disclosure, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present disclosure.

[0205] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0206] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present disclosure to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A method for detecting a vehicle braking distance, characterized in that: include: Obtaining braking data information of the target vehicle during braking; Based on the braking data information, an actual braking effect of the target vehicle is evaluated to obtain a braking effect evaluation parameter; Based on the braking effect evaluation parameter, updating the braking distance model of the target vehicle to obtain an updated braking distance model, wherein the braking distance model represents a functional relationship between the current vehicle speed and the braking distance of the target vehicle; A braking distance of the target vehicle is determined based on the updated braking distance model.

2. The method for detecting the vehicle braking distance according to claim 1, characterized in that: The braking effect evaluation parameters include a maximum braking force evaluation parameter and / or a braking response delay evaluation parameter. The actual braking effect of the target vehicle is evaluated based on the braking data information to obtain a braking effect evaluation parameter, including: Based on the braking data information, determining actual braking deceleration information of the target vehicle during braking; Determining the maximum braking force evaluation parameter based on the actual braking deceleration information and the braking command information of the target vehicle during the braking process; and / or, Based on the braking data information, the braking response delay evaluation parameter is determined.

3. The method for detecting the vehicle braking distance according to claim 2, characterized in that: The determining the maximum braking force evaluation parameter based on the actual braking deceleration information and the braking command information of the target vehicle during the braking process includes: Acquire a braking performance model of the target vehicle, wherein the braking performance model represents a functional relationship between a braking command value corresponding to the braking command information and a desired braking deceleration; Determining expected braking deceleration information based on the braking performance model and the braking instruction information; Determining the maximum braking force evaluation parameter based on the expected braking deceleration information and the actual braking deceleration information; Preferably, the method for constructing the braking performance model comprises: When the target vehicle is traveling at the maximum speed, a plurality of braking instructions are respectively requested, and the plurality of braking instructions respectively correspond to different braking instruction values; For each braking instruction, determining an actual deceleration value of the target vehicle under the braking instruction; The braking performance model is constructed based on the braking command values ​​corresponding to each of the plurality of braking commands and the actual deceleration values ​​corresponding to each of the plurality of braking commands.

4. The method for detecting the vehicle braking distance according to claim 3, characterized in that: The braking distance model includes a maximum braking force parameter. After the braking distance model of the target vehicle is updated based on the braking effect evaluation parameter to obtain an updated braking distance model, the method further includes: respectively acquiring the maximum braking force parameter and the updated maximum braking force parameter, wherein the updated maximum braking force parameter is obtained by updating the maximum braking force parameter based on the maximum braking force evaluation parameter; The braking performance model is updated based on the maximum braking force parameter and the updated maximum braking force parameter.

5. The method for detecting the vehicle braking distance according to claim 3, characterized in that: The braking instruction information includes a braking instruction value, and the braking data information includes vehicle speed information of the target vehicle. The determining, based on the braking data information, actual braking deceleration information of the target vehicle during the braking process includes: During the braking process of the target vehicle, the timing starts when the current braking deceleration of the target vehicle is greater than the preset deceleration and ends when the current vehicle speed of the target vehicle is less than the preset vehicle speed or the current braking deceleration of the target vehicle is less than the preset deceleration; Based on the vehicle speed information, determining a first vehicle speed of the target vehicle at the start time of timing and a second vehicle speed of the target vehicle at the end time of timing; determining the actual braking deceleration information based on the first vehicle speed, the second vehicle speed, and the timing duration; and / or, The step of determining expected braking deceleration information based on the braking performance model and the braking instruction information includes: determining at least one braking command value of the target vehicle during a timing process based on the braking command information; Calculating an average braking command value corresponding to the at least one braking command value; The expected braking deceleration information is determined based on the average braking command value and the braking performance model.

6. The method for detecting the vehicle braking distance according to claim 1, characterized in that: The braking distance model includes a maximum braking force parameter and a braking response delay parameter, and the braking effect evaluation parameter includes a maximum braking force evaluation parameter and / or a braking response delay evaluation parameter. The step of updating the braking distance model of the target vehicle based on the braking effect evaluation parameter to obtain an updated braking distance model includes: Obtaining a learning rate parameter of the braking distance model; determining an updated maximum braking force parameter based on the learning rate parameter, the maximum braking force evaluation parameter, and the maximum braking force parameter; determining the updated braking distance model based on the updated maximum braking force parameter; and / or, Determining the updated braking response delay parameter based on the learning rate parameter, the braking response delay evaluation parameter, and the braking response delay parameter; Determining the updated braking distance model based on the updated braking response delay parameter; Preferably, determining the updated maximum braking force parameter based on the learning rate parameter, the maximum braking force evaluation parameter, and the maximum braking force parameter comprises: determining a first maximum braking force parameter based on the maximum braking force evaluation parameter and the maximum braking force parameter; determining the updated maximum braking force parameter based on the first maximum braking force parameter, the learning rate parameter, and the maximum braking force parameter; Preferably, the braking distance model also includes at least one of the following: a vehicle mass parameter, a road surface slope parameter and a road surface rolling resistance coefficient parameter, and the braking distance is negatively correlated with the road surface rolling resistance coefficient parameter, and positively correlated with the road surface slope parameter and the vehicle mass parameter.

7. The method for detecting vehicle braking distance according to claim 1, characterized in that: The braking effect evaluation parameter includes a braking response delay evaluation parameter, and the braking data information includes braking command information of the target vehicle during the braking process. The actual braking effect of the target vehicle is evaluated based on the braking data information to obtain a braking effect evaluation parameter, including: In the case where the braking command information satisfies the slow deceleration condition, a braking response delay parameter is obtained based on the braking distance model, and the braking response delay parameter is used as the braking response delay evaluation parameter, wherein the slow deceleration condition includes: a braking command value corresponding to the braking command information is greater than the first deceleration and less than the second deceleration, and a duration corresponding to the braking command information is greater than a preset duration; or, In the case where the braking command information satisfies a non-slow deceleration condition, the braking response delay evaluation parameter is determined based on the braking data information, wherein the non-slow deceleration condition includes: at the start time of the braking process, the braking command value corresponding to the braking command information is greater than the second deceleration; Preferably, when the braking instruction information satisfies the non-slow deceleration condition, determining the braking response delay evaluation parameter based on the braking data information includes: Based on the braking data information, determining the request time corresponding to the braking instruction information and the time when the target vehicle starts to decelerate; The difference between the request time corresponding to the braking command information and the time when the target vehicle starts to decelerate is used as the braking response delay evaluation parameter.

8. The method for detecting the vehicle braking distance according to claim 1, characterized in that: The step of obtaining the braking data information of the target vehicle during the braking process includes: Acquire first braking data information of the target vehicle, where the first braking data information includes first braking command information; In a case where the first braking data information satisfies an update condition, determining that the first braking data information is the braking data information; Among them, the update conditions include at least one of the following: the target vehicle is in an unloaded state, the initial vehicle speed of the target vehicle is greater than a speed threshold, the braking command value corresponding to the first braking command information is greater than a deceleration threshold, the duration corresponding to the first braking command information is greater than a duration threshold, the absolute value of the slip rate of the target vehicle during braking is less than a slip rate threshold, and the slope of the road where the target vehicle is located is within a preset slope range.

9. A vehicle braking distance detection device, characterized in that: include: An acquisition module is configured to acquire braking data information of a target vehicle during a braking process; An evaluation module is configured to evaluate an actual braking effect of the target vehicle based on the braking data information to obtain a braking effect evaluation parameter; An updating module is configured to update the braking distance model of the target vehicle based on the braking effect evaluation parameter to obtain an updated braking distance model, wherein the braking distance model represents a functional relationship between the current vehicle speed and the braking distance of the target vehicle; A determination module is configured to determine a braking distance of the target vehicle based on the updated braking distance model.

10. An electronic device, characterized in that: include: processor; as well as A memory, configured to store executable instructions of the processor; The processor is configured to perform the method of any one of claims 1 to 8 by executing the executable instructions.

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

Images