A deceleration-adjustable adaptive braking method and system

Abstract

The application discloses a kind of deceleration adjustable adaptive braking method and system, belong to vehicle braking field.It includes: according to the driving habit of driver, establishes driving condition;For each driving condition, judge whether driver has the intention of adjusting brake deceleration under corresponding condition;When driver has the intention of adjusting brake deceleration, the actual deceleration of different pedal stroke under corresponding condition is obtained and the expected deceleration of corresponding pedal stroke is calculated;According to the expected deceleration, the motor driving torque of expected deceleration is deduced in combination with vehicle parameter, and the relationship curve of pedal stroke and motor driving torque under corresponding condition is fitted;When driver implements the pedal stroke under corresponding condition, according to the relationship curve of pedal stroke and motor driving torque under corresponding condition, the corresponding motor driving torque is output by vehicle braking system to control the output of actual deceleration.The application can adaptively adjust brake deceleration output according to the driving habit of driver.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of vehicle braking, and particularly relates to an adaptive braking method and system with adjustable deceleration. BACKGROUND

[0002] With the rapid development of intelligent driving technology, an adaptive braking system can use sensors (such as radar, camera, etc.) to monitor real-time driving information and surrounding environment, combine key information such as driver deceleration demand, following distance from the front vehicle, driving route, etc., predict potential collision risks, and increase brake force input through a hydraulic brake unit or a brake-by-wire unit to ensure that the vehicle can brake quickly and accurately in an emergency braking situation, so as to avoid collision or reduce the severity of collision.

[0003] The comparative document (CN114919548A) discloses an adaptive braking control method based on a millimeter wave radar, belonging to the field of vehicle intelligence technology, comprising the following steps: first step: judging whether the reverse lateral braking function is activated; second step: detecting moving targets in the action area of the driving vehicle RCTB through the millimeter wave radar, and if the moving target meets the collision condition with the driving vehicle, the RCTB system issues an emergency braking and alarm command, and adopts a corresponding adaptive deceleration strategy. By detecting and tracking the objects behind the vehicle through the millimeter wave, referring to the daily use scene of the vehicle and combining the ENCAP standard, a high-risk obstacle identification algorithm and strategy are designed, which can effectively identify high-risk collision targets from the rear; and according to the motion state of the vehicle and the target, the vehicle is controlled to adaptively brake, which can effectively avoid collision, improve the comfort of the driver, and greatly improve the driving safety and driving experience of the vehicle.

[0004] However, like most existing technologies, the adaptive braking system of the above comparative document is currently mainly applied to the working condition with collision risk, and has no application in the aspect of regular braking of the driver. SUMMARY

[0005] The present application aims to overcome the shortcomings of the prior art, and proposes an adaptive braking method and system with adjustable deceleration, so as to adaptively adjust the braking deceleration output according to the driving habit of the driver, meet the comfortable braking demand of different drivers, and migrate the commonly used braking driving data information of the user to a new vehicle, thereby shortening the adaptation time of the user to the vehicle.

[0006] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0007] An adaptive braking method with adjustable deceleration, comprising the following steps:

[0008] Step S1: establishing a plurality of driving conditions according to the driving habit of the driver;

[0009] Step S2, for each driving condition, determine whether the driver has the intention to adjust the braking deceleration under the corresponding condition;

[0010] Step S3, when the driver has the intention to adjust the braking deceleration, obtain the actual deceleration of different pedal strokes under the corresponding condition, and calculate the expected deceleration corresponding to the pedal stroke;

[0011] Step S4, according to the expected deceleration, combined with the vehicle parameters, the expected deceleration corresponding to the motor driving torque is backstepped, and the relationship curve of the pedal stroke and the motor driving torque under the corresponding condition is finally fitted;

[0012] Step S5, when the driver implements the pedal stroke under the corresponding condition, according to the relationship curve of the pedal stroke and the motor driving torque under the corresponding condition, the vehicle braking system outputs the corresponding motor driving torque to control the output of the actual deceleration.

[0013] Preferably, the step S1 comprises:

[0014] Step S11, when detecting that the driver implements the braking, record the corresponding vehicle state data, including the vehicle speed at the beginning of the braking, the distance of other vehicle following or obstacle, the steering wheel angle, the change gradient of the brake pedal stroke; a plurality of vehicle state data constitutes a vehicle state data set;

[0015] Step S12, the vehicle state data set is divided according to the preset range, and the segmented vehicle state data set in different data ranges is obtained, and each segmented vehicle state data set corresponds to a driving condition label.

[0016] Preferably, before the step S2, the method further comprises: when detecting that the driver brakes, determining whether the current driving condition exists; when the current driving condition exists, continuing to execute the step S2; when the current driving condition does not exist, establishing a driving condition label for the vehicle state data under the current driving condition, and continuing to execute the step S2.

[0017] Preferably, in the step S2, whether the driver has the intention to adjust the braking deceleration is determined by the pedal stroke change and the pedal stroke change gradient between the current sampling point and the previous sampling point; the determination condition of whether the driver has the intention to adjust the braking deceleration is as follows:

[0018] (1) the pedal stroke change is greater than the set first change threshold and the pedal stroke change is less than the set second change threshold, wherein the first change threshold is less than the second change threshold;

[0019] (2) pedal stroke change gradient is greater than a set first change gradient threshold and pedal stroke change gradient is less than a set second change gradient threshold, wherein the first change gradient threshold is less than the second change gradient threshold;

[0020] When (1) and (2) are met simultaneously, it indicates that the driver has an intention to adjust the brake deceleration, otherwise it indicates that the driver has no intention to adjust the brake deceleration or there is an emergency brake intention; when the pedal stroke becomes smaller and the pedal stroke change gradient is negative, the driver expects to reduce the brake deceleration; when the pedal stroke becomes larger and the pedal stroke change gradient is positive, the driver expects to increase the brake deceleration.

[0021] Preferably, in the step 2, the driving conditions of the emergency brake and the auxiliary brake are also filtered, that is, when the driving condition appears any of the following conditions, the corresponding driving condition is excluded: the pedal stroke is greater than a set stroke threshold; the pedal stroke change gradient is greater than a set second change gradient threshold; the vehicle deceleration is greater than a set deceleration threshold; the anti-lock brake system is activated; the brake auxiliary system is activated.

[0022] Preferably, in the step S3, when the driver has an intention to adjust the brake deceleration, the deceleration and the pedal stroke at the current time t and the last time t-1 are obtained, a t and a t-1 respectively correspond to the deceleration at the current time t and the last time t-1; s t and s t-1 respectively correspond to the pedal stroke at the current time t and the last time t-1; wherein a t-1 is the actual deceleration of the pedal stroke s t-1 under the current driving condition; then the expected deceleration of the pedal stroke s t-1 under the current driving condition is Min(a t-1 ±0.1m / s 2 , (a t +a t-1 ) / 2), wherein Min(a t-1 -0.1m / s 2 , (a t +a t-1 ) / 2) indicates that the driver expects to reduce the deceleration, and Min(a t-1 +0.1m / s 2 , (a t +a t-1 ) / 2) indicates that the driver expects to increase the deceleration.

[0023] Preferably, before the step S5, the method further comprises repeatedly executing the steps S2 to S4 to constantly update the relationship curve between the pedal stroke and the motor driving torque under the corresponding driving condition.

[0024] Preferably, in the step S4, the method further comprises storing the relationship curve between the pedal stroke and the motor driving torque under the corresponding driving condition in the cloud server for data migration when the vehicle is replaced.

[0025] Preferably, when the data migration is performed, the relationship curve between the pedal stroke and the motor driving torque under the corresponding driving condition is stored in the cloud server, so that the motor driving torque is converted into the expected deceleration according to the vehicle parameters of the original vehicle to obtain the relationship curve between the pedal stroke and the expected deceleration under different driving conditions, and then the relationship curve between the pedal stroke and the motor driving torque of the new vehicle is obtained by back calculation according to the vehicle parameters of the new vehicle.

[0026] Meanwhile, the application also proposes a self-adaptive braking system with adjustable deceleration, which is configured according to the self-adaptive braking method with adjustable deceleration, and comprises a sensor unit, a controller and a braking unit, wherein the controller is connected with the sensor unit and the braking unit respectively; the sensor unit is used for collecting vehicle state data and sending the vehicle state data to the controller; the controller is used for processing the vehicle state data according to the self-adaptive braking method with adjustable deceleration to adjust the motor driving torque output by the braking unit to control the output of the actual deceleration.

[0027] The technical effect of the application is that the application adjusts the motor driving torque output by the vehicle braking system by identifying the braking deceleration adjustment intention of the driver and combining the actual output deceleration corresponding to the pedal stroke, so that the actual output deceleration constantly approaches the expected deceleration, the purpose of self-adaptive adjustment of the braking deceleration output according to the driving habit of the driver is achieved, the comfortable braking demand of different drivers is met, and the commonly used braking driving data information of the user can be migrated to a new vehicle, thereby shortening the adaptation time of the user to the vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is a flow chart of a self-adaptive braking method with adjustable deceleration according to an embodiment of the application. DETAILED DESCRIPTION

[0029] The specific embodiments of the application will be further described below with reference to the drawings, and the purpose of the description of the embodiments is to help the skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the application, and to facilitate the implementation. It should be noted that the terms "first", "second" and the like in the present application are only convenient for describing the technical solutions to distinguish different components, and do not limit the application. In order to make the technical solution of the application more clear, the application is explained and described by the following embodiments.

[0030] The application provides a self-adaptive braking method with adjustable deceleration, which comprises the following steps:

[0031] Step S1, a plurality of driving conditions are established according to the driving habits of the driver.

[0032] Step S2, for each driving condition, it is judged whether the driver has an intention to adjust the braking deceleration under the corresponding condition.

[0033] Step S3, when the driver has an intention to adjust the braking deceleration, the actual deceleration of different pedal strokes under the corresponding condition is obtained, and the expected deceleration of the corresponding pedal stroke is calculated.

[0034] Step S4, according to the expected deceleration, the motor driving torque corresponding to the expected deceleration is back calculated in combination with the vehicle parameters, and finally the relationship curve between the pedal stroke and the motor driving torque under the corresponding condition is fitted.

[0035] Step S5, when the driver implements the pedal stroke under the corresponding condition, the corresponding motor driving torque is output by the vehicle braking system according to the relationship curve between the pedal stroke and the motor driving torque under the corresponding condition to control the output of the actual deceleration.

[0036] In the following, the embodiment is specifically described in combination with the flow chart as shown in the figure. Figure 1

[0037] Step S1, a plurality of driving conditions are established according to the driving habits of the driver. Specifically, the step S1 comprises:

[0038] Step S11, when the driver implements braking, the corresponding vehicle state data is recorded, including the vehicle speed at the beginning of braking, the distance of other vehicles following or obstacles, the steering wheel angle, the change gradient of the brake pedal stroke. In the embodiment, the wheel speed sensor collects the vehicle speed; the radar and camera collect the distance of other vehicles following or obstacles; the pedal stroke displacement sensor collects the change amount and gradient of the brake pedal stroke; the steering wheel angle sensor collects the steering wheel angle and other information to record the vehicle state data, which often corresponds to the driving habits of the driver. A plurality of vehicle state data constitutes a vehicle state data set.

[0039] Step S12, the vehicle state data set is divided according to a preset range to obtain segmented vehicle state data sets in different data ranges, each segmented vehicle state data set corresponds to a driving condition label, and each driving condition label can represent a driving habit of a driver.

[0040] ​Since the driving habits of the driver can change, the driving condition established in step S1 can not cover all cases, so before step S2, the adaptive braking method of the embodiment further includes: when detecting that the driver brakes, judging whether the current driving condition exists; when the current driving condition exists, continuing to execute step S2; when the current driving condition does not exist, establishing a driving condition label for the vehicle state data in the current driving condition, and continuing to execute step S2. Thus, the driving condition is continuously expanded to cover more driving habits.

[0041] Step S2, for each driving condition, judging whether the driver has an intention to adjust the braking deceleration under the corresponding condition.

[0042] Specifically, step S2 of the embodiment includes: judging whether the driver has an intention to adjust the braking deceleration by the pedal stroke change amount and the pedal stroke change gradient between the current sampling point and the previous sampling point; the determination condition of whether the driver has an intention to adjust the braking deceleration is as follows:

[0043] (1) The pedal stroke change amount is greater than a set first change amount threshold and the pedal stroke change amount is less than a set second change amount threshold, wherein the first change amount threshold is less than the second change amount threshold; in the embodiment, the total pedal stroke is 100 mm, the first change amount threshold can be set to ±2 mm, and the second change amount threshold can be set to ±15 mm.

[0044] (2) The pedal stroke change gradient is greater than a set first change gradient threshold and the pedal stroke change gradient is less than a set second change gradient threshold, wherein the first change gradient threshold is less than the second change gradient threshold; in the embodiment, the total pedal stroke is 100 mm, the first change gradient threshold can be set to 1 mm / s, and the second change gradient threshold can be set to 250 mm / s.

[0045] When (1) and (2) are met at the same time, it means that the driver has an intention to adjust the braking deceleration, otherwise it means that the driver has no intention to adjust the braking deceleration or there is an emergency braking intention; when the pedal stroke becomes smaller and the pedal stroke change gradient is negative, the driver expects to reduce the braking deceleration; when the pedal stroke becomes larger and the pedal stroke change gradient is positive, the driver expects to increase the braking deceleration.

[0046] Since in actual driving, the driver may cause emergency braking and auxiliary braking due to obstacle avoidance and other reasons, but this situation is occasional and has a very low probability in a regular braking environment, so before step 2, the driving conditions of emergency braking and auxiliary braking are also filtered, that is, when the driving condition appears any of the following situations, the corresponding driving condition is excluded: the pedal stroke is greater than the set stroke threshold (in this embodiment, the total pedal stroke is 100 mm, and the corresponding stroke threshold can be set to 80 mm); the pedal stroke change gradient is greater than the set second change gradient threshold (250 mm / s in this embodiment); the vehicle deceleration is greater than the set deceleration threshold; the anti-lock braking system is activated; the brake assist system is activated.

[0047] Step S3, when the driver has an intention to adjust the brake deceleration, the actual deceleration of different pedal strokes under the corresponding working condition is obtained, and the expected deceleration of the corresponding pedal stroke is calculated

[0048] Specifically, in the step S3, when the driver has an intention to adjust the brake deceleration, the deceleration and pedal stroke at the current time t and the last time t-1 are obtained, the deceleration can be obtained by the IMU (inertial measurement unit) combined sensor, a t and a t-1 respectively correspond to the deceleration at the current time t and the last time t-1; s t and s t-1 respectively correspond to the pedal stroke at the current time t and the last time t-1; wherein a t-1 is the actual deceleration of the pedal stroke s t-1 under the current driving condition; then the expected deceleration of the pedal stroke s t-1 under the current driving condition is Min(a t-1 ±0.1m / s 2 , (a t +a t-1 ) / 2), wherein Min(a t-1 -0.1m / s 2 , (a t +a t-1 ) / 2) indicates that the driver expects to reduce the deceleration, and Min(a t-1 +0.1m / s 2 , (a t +a t-1 ) / 2) indicates that the driver expects to increase the deceleration.

[0049] Step S4, according to the expected deceleration, combined with the vehicle parameters (such as pedal characteristic parameters, etc.), the corresponding motor driving torque of the expected deceleration is deduced, and finally the relationship curve of the pedal stroke and the motor driving torque under the corresponding working condition is fitted. The conversion between deceleration and motor driving torque is a common technical means for those skilled in the art, and the present application will not repeat it. It is worth mentioning that due to the difference of different vehicle parameters, the relationship between the pedal stroke and the motor driving torque of different vehicles will also change.

[0050] In step S4 of the present embodiment, the method further comprises storing the relationship curve of the pedal stroke and the motor driving torque under the corresponding working condition in the cloud server for data migration when the vehicle is replaced. When data migration is performed, the relationship curve of the pedal stroke and the motor driving torque under the corresponding working condition is stored in the cloud server, so the motor driving torque is first converted into the expected deceleration according to the vehicle parameters of the original vehicle, and the relationship curve of the pedal stroke and the expected deceleration under different driving conditions is obtained, and then the relationship curve of the pedal stroke and the motor driving torque is obtained by reverse deduction according to the vehicle parameters of the new vehicle.

[0051] In order to make the actual deceleration output gradually approach the deceleration expected by the driver, before step S5, the method of the present embodiment further comprises repeatedly executing steps S2 to S4 to constantly update the relationship curve of the pedal stroke and the motor driving torque under the corresponding working condition.

[0052] Step S5, when the driver implements the pedal stroke under the corresponding working condition, according to the relationship curve of the pedal stroke and the motor driving torque under the corresponding working condition, the vehicle braking system outputs the corresponding motor driving torque to control the output of the actual deceleration.

[0053] In summary, the present embodiment can adaptively adjust the braking deceleration according to the driving habit of the driver, and meet the comfortable braking needs of different drivers; at the same time, the commonly used braking driving data information of the user can be migrated to the new vehicle, and the adaptation time of the user to the vehicle is shortened.

[0054] Meanwhile, the present embodiment also proposes a self-adaptive braking system with adjustable deceleration, which is configured according to the above-mentioned self-adaptive braking method with adjustable deceleration, comprising a sensor unit, a controller and a braking unit, wherein the controller is connected with the sensor unit and the braking unit respectively; the sensor unit is used to collect vehicle state data and send it to the controller; the controller is used to process the vehicle state data according to the above-mentioned self-adaptive braking method with adjustable deceleration, so as to adjust the motor driving torque output by the braking unit to control the output of the actual deceleration.

[0055] Preferably, the braking unit comprises a decoupled hydraulic braking unit or a brake-by-wire unit, etc., which can be flexibly selected according to the actual situation.

[0056] The application has been described above by way of illustration, and not limitation, with reference to the accompanying drawings. It will be apparent to a person skilled in the art that modifications can be made without departing from the scope of the application. Any modifications made to the above-described concept and technical solutions of the application, or direct application of the above-described concept and technical solutions of the application to other fields, are within the scope of the application.

Claims

1. An adaptive braking method with adjustable deceleration, characterized by: The method comprises the following steps: Step S1: establishing multiple driving conditions according to the driver's driving habits; Step S2: for each driving condition, determining whether the driver intends to adjust the braking deceleration under the corresponding condition; Step S3: When the driver intends to adjust the braking deceleration, the actual deceleration of the pedal stroke under the corresponding working condition is obtained, and the expected deceleration of the corresponding pedal stroke is calculated; wherein, when the driver intends to adjust the braking deceleration, the deceleration and pedal stroke at the current time t and the previous time t-1 are obtained, a t and a t-1 They correspond to the deceleration at the current time t and the previous time t-1 respectively; s t and s t-1 They correspond to the pedal stroke at the current time t and the previous time t-1 respectively; where a t-1 That is the pedal travel s under the current driving condition t-1 The actual deceleration; then the pedal travel s under the current driving condition t-1 The expected deceleration is Min(a t-1 ±0.1m / s 2 ,(a t +a t-1 ) / 2), where Min(a t-1 -0.1m / s 2 ,(a t +a t-1 ) / 2) indicates that the driver expects to reduce deceleration, Min(a t-1 +0.1m / s 2 ,(a t +a t-1 ) / 2) indicates that the driver expects to increase the deceleration; Step S4: inversely deriving the motor driving torque corresponding to the expected deceleration based on the expected deceleration and the vehicle parameters, and finally fitting a relationship curve between the pedal stroke and the motor driving torque under the corresponding working condition; Step S5: When the driver implements the pedal stroke under the corresponding working condition, the vehicle braking system outputs the corresponding motor driving torque to control the output of the actual deceleration according to the relationship curve between the pedal stroke and the motor driving torque under the corresponding working condition.

2. The adaptive braking method with adjustable deceleration according to claim 1, characterized in that: The step S1 comprises: Step S11: When it is detected that the driver has applied brakes, corresponding vehicle status data is recorded, including the vehicle speed at the start of braking, the distance to other vehicles following or obstacles, the steering wheel angle, and the gradient of the brake pedal travel; the plurality of vehicle status data constitute a vehicle status data set; Step S12: Divide the vehicle state data set according to a preset range to obtain segmented vehicle state data sets in different data ranges, each segmented vehicle state data set corresponding to a driving condition label.

3. The adaptive braking method with adjustable deceleration according to claim 1 or 2, characterized in that: Before step S2, the method further includes: when detecting that the driver is braking, determining whether the current driving condition exists; when the current driving condition exists, continuing to execute step S2; when the current driving condition does not exist, establishing a separate driving condition label for the vehicle status data under the current driving condition, and continuing to execute step S2.

4. The adaptive braking method with adjustable deceleration according to claim 1, characterized in that: In step S2, whether the driver intends to adjust the braking deceleration is determined by the pedal stroke change amount and the pedal stroke change gradient between the current sampling point and the previous sampling point. The determination conditions for whether the driver intends to adjust the braking deceleration are as follows: (1) The pedal stroke change is greater than a set first change threshold and the pedal stroke change is less than a set second change threshold, wherein the first change threshold is less than the second change threshold; (2) The pedal stroke change gradient is greater than a set first change gradient threshold and the pedal stroke change gradient is less than a set second change gradient threshold, wherein the first change gradient threshold is less than the second change gradient threshold; When (1) and (2) are satisfied at the same time, it means that the driver has the intention to adjust the braking deceleration; otherwise, it means that the driver has no intention to adjust the braking deceleration or has the intention of emergency braking; when the pedal stroke becomes smaller and the pedal stroke change gradient is negative, the driver expects to reduce the braking deceleration; when the pedal stroke becomes larger and the pedal stroke change gradient is positive, the driver expects to increase the braking deceleration.

5. The adaptive braking method with adjustable deceleration according to claim 4, characterized in that: In step 2, the driving conditions of emergency braking and auxiliary braking are also filtered, that is, when any of the following conditions occurs in the driving condition, the corresponding driving condition is excluded: the pedal stroke is greater than the set stroke threshold; The pedal travel change gradient is greater than the set second change gradient threshold; the vehicle deceleration is greater than the set deceleration threshold; the anti-lock braking system is activated; the brake assist system is activated.

6. The adaptive braking method with adjustable deceleration according to claim 1, characterized in that: Before step S5, the method further includes repeatedly executing steps S2 to S4, and continuously iteratively updating the relationship curve between the pedal stroke and the motor driving torque under the corresponding working condition.

7. The adaptive braking method with adjustable deceleration according to claim 1, characterized in that: In step S4, the method further includes storing a relationship curve between the pedal stroke and the motor driving torque under corresponding working conditions in a cloud server for data migration when the vehicle is replaced.

8. The adaptive braking method with adjustable deceleration according to claim 7, characterized in that: During data migration, the cloud server stores the relationship curve between the pedal stroke and the motor drive torque under the corresponding working conditions. Therefore, the motor drive torque is first converted into the expected deceleration based on the original vehicle parameters to obtain the relationship curve between the pedal stroke and the expected deceleration under different driving conditions. Then, the relationship curve between the pedal stroke and the motor drive torque of the new vehicle is obtained by reverse calculation based on the vehicle parameters of the new vehicle.

9. An adaptive braking system with adjustable deceleration, characterized by: The system is configured according to the adaptive braking method with adjustable deceleration according to any one of claims 1 to 8, and includes a sensor unit, a controller, and a braking unit, wherein the controller is connected to the sensor unit and the braking unit, respectively; the sensor unit is used to collect vehicle status data and send it to the controller; the controller is used to process the vehicle status data according to the adaptive braking method with adjustable deceleration according to any one of claims 1 to 8, thereby adjusting the motor driving torque output by the braking unit to control the output of the actual deceleration.

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