Vehicle brake control method

Abstract

The invention relates to a braking control method for a vehicle, and the method comprises the steps: receiving a first signal from an automatic driving system, and enabling the first signal to indicate that the automatic driving system requests to stop the vehicle; determining a stop expectation of the vehicle based on the first signal and an actual speed of the vehicle; and when it is determined that the stop is expected to be 'true', calculating an anti-back-slip braking force Fxroll during the period of receiving the first signal, the anti-back-slip braking force Fxroll being determined at least according to a propulsive force Fxprop of the vehicle, an actual braking force Fxbrakeact of the vehicle and a gradient, so that the vehicle can be completely braked on different ramps. The application also relates to a computer program product and a domain controller.

Description

Technical Field

[0001] This application relates to the field of autonomous driving, and more specifically, to a braking control method, computer program product, and domain controller for a vehicle. Background Technology

[0002] In current autonomous driving systems, the ratio of vehicle speed to deceleration is generally used to detect the expected stop of the vehicle. Here, "expected stop" is a Boolean value; when it is "true," it means that the vehicle needs to stop, while when it is "false," it means that the vehicle does not need to stop.

[0003] However, existing methods for detecting stop expectation are not accurate enough in certain extreme scenarios. The results of stop expectation detection directly affect whether the braking system generates sufficient braking force, thus impacting vehicle safety. Summary of the Invention

[0004] The inventors of this application recognized that in certain scenarios of autonomous driving systems (such as the stop-and-go scenario of adaptive cruise control (ACC), because the vehicle is at a low speed and the target deceleration is small, it may not be able to effectively trigger the stop expectation to be "true," resulting in the holding pressure required to keep the vehicle stationary being usually too low. In this case, if the vehicle is on a slope, because the braking system fails to build up sufficient pressure, the vehicle may roll backward due to gravity.

[0005] According to one aspect of this application, a braking control method for a vehicle is provided, the method comprising: receiving a first signal from an autonomous driving system, the first signal instructing the autonomous driving system to request that the vehicle be stopped; determining a stopping expectation of the vehicle based on the first signal and the actual speed of the vehicle; and, when the stopping expectation is determined to be "true", calculating an anti-rollback braking force Fx during the receipt of the first signal. rollout The anti-rollback braking force Fx rollout At least according to the propulsion force Fx of the vehicle prop The actual braking force Fx of the vehicle brake_act The gradient is determined so that the vehicle can come to a complete stop on different slopes.

[0006] As a supplement or replacement to the above scheme, in the above method, the first signal is a stationary request from the adaptive cruise control system (ACC).

[0007] As a supplement or replacement to the above scheme, in the above method, determining the expected stop of the vehicle based on the first signal and the actual speed of the vehicle includes: when the first signal is received and the actual speed of the vehicle is less than a first threshold, determining that the expected stop of the vehicle is "true".

[0008] As a supplement or replacement to the above scheme, the above method further includes: detecting the expected stopping of the vehicle based on the ratio of the vehicle's actual speed to its deceleration.

[0009] As a supplement or replacement to the above scheme, in the above method, when the ratio is less than the second threshold, the expected stop of the vehicle is determined to be "true".

[0010] As a supplement or replacement to the above solution, in the above method, the anti-rollback braking force Fx rollout Determined according to the following formula:

[0011] Fx rollout =m*a-Fx prop -Fx brake_act -Fx offset ,

[0012] Where m is the mass of the vehicle, a is the acceleration of the vehicle, and Fx rollout For the anti-rollback braking force, Fx prop The propulsion force of the vehicle, Fx brake_act The actual braking force of the vehicle and Fx offset The offset force is calculated based on the slope, and the parameter values ​​involved in the above formula are signed, being positive along the direction of vehicle travel and negative otherwise.

[0013] As a supplement or replacement to the above scheme, in the above method, the anti-backward braking force is a negative value, and the offset force is a positive value with an offset amount preset according to the slope.

[0014] As a supplement or replacement to the above solution, the above method may further include: applying the anti-rollback braking force Fx rollout With preset minimum braking force Fx min The two are compared, and the smaller of the two is provided to the vehicle stability system ESP or the integrated parking brake IPB for braking, wherein the preset minimum braking force Fx min Determined based on the slope.

[0015] According to another aspect of this application, a braking control device for a vehicle is provided, the device comprising: a stop expectation module configured to: receive a first signal from an autonomous driving system, the first signal instructing the autonomous driving system to request that the vehicle stop, and determine a stop expectation for the vehicle based on the first signal and the actual speed of the vehicle; and an anti-rollback module configured to calculate an anti-rollback braking force Fx during the receipt of the first signal when the stop expectation is determined to be "true". rollout The anti-rollback braking force Fx rolloutAt least according to the propulsion force Fx of the vehicle prop The actual braking force Fx of the vehicle brake_act The gradient is determined so that the vehicle can come to a complete stop on different slopes.

[0016] According to another aspect of this application, a computer program product is provided, including a computer program that, when executed by a processor, implements the method described above.

[0017] According to another aspect of this application, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the method described above.

[0018] According to another aspect of this application, a domain controller is provided, including a memory, a processor, and a computer program stored in the memory, the processor executing the computer program to implement the method as described above.

[0019] The braking control scheme for vehicles in embodiments of this application introduces a first signal (indicating that the autonomous driving system requests the vehicle to stop) into the detection of the vehicle's expected stop. This detection is more accurate than existing schemes and can effectively bring the vehicle to a complete stop on various inclines. Furthermore, at least based on the vehicle's propulsion force Fx... prop The actual braking force Fx of the vehicle brake_act And the slope determines the anti-rollback braking force Fx rollout This fully takes into account the impact of different electronic control units (ECUs).

[0020] In one or more embodiments, the vehicle's expected stop is determined to be "true" when a first signal is received and the vehicle's actual speed is less than a first threshold. That is, if the vehicle's actual speed is greater than the first threshold, the expected stop is "false" even if the first signal (which instructs the autonomous driving system to request the vehicle to stop) is received. This embodiment avoids untimely braking actions while the vehicle is at high speed.

[0021] In one or more embodiments, the braking control scheme for a vehicle also limits the minimum braking force provided to the braking system, i.e., the anti-rollover braking force Fx. rollout With preset minimum braking force Fx min Compare the two and determine the smaller one (due to the anti-rollback braking force Fx). rollout With preset minimum braking force Fx minAll values ​​are negative, so the smaller the value, the larger the absolute value. This information is provided to the Electronic Stability Program (ESP) or the Integrated Parking Brake (IPB) for braking. The purpose of this is to ensure that the vehicle remains safely stationary even under the most unfavorable slope conditions, and does not roll backward due to insufficient braking force. Attached Figure Description

[0022] The above and other objects and advantages of this application will become more fully clear from the following detailed description taken in conjunction with the accompanying drawings, wherein the same or similar elements are denoted by the same reference numerals.

[0023] Figure 1 A schematic flowchart of a braking control method for a vehicle according to an embodiment of this application is shown; and

[0024] Figure 2 A schematic diagram of a braking control device for a vehicle according to an embodiment of this application is shown. Detailed Implementation

[0025] In the following, braking control schemes for vehicles according to various exemplary embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0026] Figure 1 A schematic flowchart of a braking control method 1000 for a vehicle according to an embodiment of this application is shown. Figure 1 As shown, the braking control method 1000 includes the following steps:

[0027] In step S110, a first signal is received from the autonomous driving system, the first signal indicating that the autonomous driving system requests the vehicle to stop;

[0028] In step S120, the expected stopping of the vehicle is determined based on the first signal and the actual speed of the vehicle; and

[0029] In step S130, when the stop expectation is determined to be "true", the anti-rollback braking force Fx is calculated during the receipt of the first signal. rollout The anti-rollback braking force Fx rollout At least according to the propulsion force Fx of the vehicle prop The actual braking force Fx of the vehicle brake_act The gradient is determined so that the vehicle can come to a complete stop on different slopes.

[0030] In the context of this application, the term "autonomous driving system" refers to a system that tightly integrates artificial intelligence with various sensor technologies to endow a vehicle with autonomous operating capabilities. This term includes, but is not limited to, driver assistance systems, such as ADAS systems. In one or more embodiments, an ADAS system includes a series of assistance functions or subsystems, such as adaptive cruise control (ACC), lane keeping assist (LDW), traffic sign recognition (TSR), automatic emergency braking (AEB), etc. These functions or systems perceive the vehicle's surrounding environment through sensor technology and analyze and process information through technologies such as computer vision and machine learning to provide assistance functions to improve driving safety and comfort. The sensors in an ADAS system mainly include cameras, radar, lasers, and ultrasonic sensors, which are typically mounted on the front and rear bumpers, side mirrors, inside the steering column, or on the windshield of the vehicle.

[0031] In step S110, a first signal is received from the autonomous driving system, indicating that the autonomous driving system requests the vehicle to stop. In one embodiment, the first signal is a stop request from the adaptive cruise control system (ACC). This means that the ACC has detected a situation requiring stopping, such as a vehicle ahead stopping or approaching traffic congestion, and requests the vehicle to perform a stopping operation by sending a signal. The above steps introduce the first signal (i.e., the request from the autonomous driving system) into the braking control method 1000, ensuring that the vehicle can respond to the instructions from the autonomous driving system and safely perform the stopping operation. This integrated control scheme improves driving safety and comfort and is the foundation for achieving higher levels of autonomous driving functions.

[0032] In step S120, the expected stopping of the vehicle is determined based on the first signal and the actual speed of the vehicle. In the context of this application, the term "expected stopping" refers to predicting whether the vehicle needs to stop based on current driving conditions, sensor inputs, and driver actions. For example, "expected stopping" is a Boolean value, where "true" indicates that the vehicle needs to stop, and "false" indicates that the vehicle does not need to stop.

[0033] In one embodiment, step S120 includes: upon receiving the first signal and when the actual speed of the vehicle is less than a first threshold (e.g., a preset value), determining that the vehicle's stopping expectation is "true". The decision logic is: if both the first signal being received and the vehicle speed being below the first threshold are met simultaneously, then the vehicle is considered to need to stop, i.e., the stopping expectation is "true". Once the stopping expectation is determined to be "true", the system will execute subsequent parking procedures, including but not limited to calculating braking force, decelerating to a stop, and keeping the vehicle stationary after stopping. This stopping expectation judgment mechanism based on the first signal and actual speed aims to improve the safety and efficiency of vehicle parking, ensuring safe parking at appropriate times and under appropriate conditions.

[0034] although Figure 1 As not shown in the diagram, in one embodiment, the method 1000 further includes: detecting a stopping expectation of the vehicle based on the ratio of the vehicle's actual speed to its deceleration. For example, if the ratio is less than a second threshold, the stopping expectation of the vehicle is determined to be "true". In this embodiment, the detection method based on the speed-to-deceleration ratio is integrated with the detection method based on a first signal and a speed threshold to provide a more comprehensive stopping expectation analysis.

[0035] In other words, the vehicle's expected stop will be determined as "true" if one of the following two conditions is met:

[0036] (1) Upon receiving the first signal and the actual speed of the vehicle being less than the first threshold; or

[0037] (2) The ratio of the vehicle’s actual speed to its deceleration is less than the second threshold.

[0038] Understandably, if neither of the above two conditions is met, the expected stopping of the vehicle is determined to be "false".

[0039] In step S130, when the stop expectation is determined to be "true", the anti-rollback braking force Fx is calculated during the receipt of the first signal. rollout The anti-rollback braking force Fx rollout At least according to the propulsion force Fx of the vehicle prop The actual braking force Fx of the vehicle brake_act The gradient is determined so that the vehicle can come to a complete stop on different slopes.

[0040] In step S130, when the stop expectation is determined to be "true", meaning the vehicle needs to stop, the system calculates the anti-rollback braking force Fx. rollout The calculation of this braking force is based on at least the following key factors: (1) the vehicle's propulsion force Fx prop:This is the minimum propulsive force required for the vehicle to prevent it from rolling backward on a slope. It ensures that the vehicle does not slide down the slope (overcoming the component of gravity); (2) The actual braking force Fx of the vehicle brake_act :This is the actual braking force currently used by the vehicle; (3) Slope: The slope of the slope where the vehicle is located directly affects the required braking force; the greater the slope, the greater the braking force required to prevent the vehicle from rolling backward.

[0041] Anti-rollback braking force Fx rollout The calculations ensure that the vehicle can come to a complete stop on different slopes without rolling backward. This calculation process is an important safety feature in the vehicle control system, especially when parking on a slope, providing the necessary braking force to maintain vehicle stability.

[0042] In one embodiment, the anti-rollback braking force Fx rollout Determined according to the following formula:

[0043] Fx rollout =m*a-Fx prop -Fx brake_act -Fx offset ,

[0044] Where m is the mass of the vehicle, a is the acceleration of the vehicle, and Fx rollout For the anti-rollback braking force, Fx prop The propulsion force of the vehicle, Fx brake_act The actual braking force of the vehicle and Fx offset The offset force is calculated based on the slope, and the parameter values ​​involved in the above formula are signed, being positive along the direction of vehicle travel and negative otherwise.

[0045] It is understandable that the anti-rollback braking force is negative, and in one or more embodiments, the offset force Fx offset This is a deviation based on the slope to prevent insufficient braking force calculation; this value is positive.

[0046] In one embodiment, the calculated anti-rollback braking force Fx will also be... rollout With preset minimum braking force Fx min (Determined based on the slope) The two values ​​are compared, and the smaller one (i.e., the larger absolute value) is used as the final braking force provided to the Electronic Stability Program (ESP) or the Integrated Parking Brake (IPB) for braking. In this embodiment, Fx min This setting is to prevent Fx rollout The calculated output force is too small, limiting the minimum braking force when stopping on different slopes, ensuring that the braking force on different slopes can completely stop the vehicle without it rolling away.

[0047] Furthermore, those skilled in the art will readily understand that the braking control method 1000 for a vehicle provided in one or more embodiments of this application can be implemented by a computer program. For example, the computer program is included in a computer program product, and when executed by a processor, it implements the braking control method 1000 for a vehicle according to one or more embodiments of this application. As another example, when a computer-readable storage medium (e.g., a USB flash drive) storing the computer program is connected to a computer, running the computer program executes one or more embodiments of this application, the braking control method 1000 for a vehicle.

[0048] Furthermore, the braking control method 1000 for a vehicle provided in one or more embodiments of this application can also be integrated into a domain controller. In one embodiment, the domain controller includes a memory, a processor, and a computer program stored in the memory, the processor executing the computer program to implement one or more embodiments of this application, the braking control method 1000 for a vehicle.

[0049] refer to Figure 2 It shows a schematic diagram of a braking control device 2000 for a vehicle according to one embodiment of this application. Figure 2 As shown, the braking control device 2000 includes a stop expectation module 210 and an anti-rollback module 220. The stop expectation module 210 is configured to: receive a first signal from an autonomous driving system, the first signal instructing the autonomous driving system to request the vehicle to stop, and determine a stop expectation for the vehicle based on the first signal and the actual speed of the vehicle. The anti-rollback module 220 is used to calculate an anti-rollback braking force Fx during the receipt of the first signal when the stop expectation is determined to be "true". rollout The anti-rollback braking force Fx rollout At least according to the propulsion force Fx of the vehicle prop The actual braking force Fx of the vehicle brake_act The gradient is determined so that the vehicle can come to a complete stop on different slopes.

[0050] In one embodiment, the first signal received by the stop expectation module 210 is a stop request from the adaptive cruise control system ACC.

[0051] In one embodiment, the stop expectation module 210 is configured to determine that the vehicle's stop expectation is "true" when a first signal is received and the actual speed of the vehicle is less than a first threshold.

[0052] In one embodiment, the stop prediction module 210 may be further configured to detect the vehicle's stop prediction based on the ratio of the vehicle's actual speed to its deceleration. Wherein, the vehicle's stop prediction is determined to be "true" when the ratio is less than a second threshold. That is, the stop prediction module 210 determines the vehicle's stop prediction to be "true" when one of the following two conditions is met:

[0053] (1) Upon receiving the first signal and the actual speed of the vehicle being less than the first threshold; or

[0054] (2) The ratio of the vehicle’s actual speed to its deceleration is less than the second threshold.

[0055] It is understandable that in the above embodiments, if neither of the above two conditions is met, the stop expectation module 210 determines that the vehicle stop expectation is "false".

[0056] In one embodiment, the anti-rollback module 220 calculates the anti-rollback braking force Fx according to the following formula. rollout :

[0057] Fx rollout =m*a-Fx prop -Fx brake_act -Fx offset ,

[0058] Where m is the mass of the vehicle, a is the acceleration of the vehicle, and Fx rollout To prevent backward slippage braking force, Fx prop For the vehicle's propulsion, Fx brake_act For the vehicle's actual braking force and Fx offset This represents the offset force calculated based on the slope. It should also be noted that the parameter values ​​in the above formula are signed, with positive values ​​for the direction of vehicle travel and negative values ​​for the other direction.

[0059] In one or more embodiments, the anti-rollback braking force is negative, and the offset force Fx offset This is a deviation based on the slope to prevent insufficient braking force calculation; this value is positive.

[0060] In one embodiment, the anti-rollback module 220 is further configured to use the calculated anti-rollback braking force Fx rollout With preset minimum braking force Fx min (Determined based on the slope) The two are compared, and the smaller of the two is used as the final braking force to provide to the vehicle stability system ESP or the integrated parking brake IPB for braking.

[0061] In one or more embodiments, the braking control device 2000 for a vehicle can be implemented in a controlled deceleration unit (CDD) of a driver assistance system. For example, in a CDD-only architecture, the controlled deceleration unit (CDD) is only responsible for the vehicle's deceleration process. Alternatively, the controlled deceleration unit (CDD) can be combined with a vehicle longitudinal controller (VLC) to control both vehicle acceleration and deceleration. For example, in a VLC+CDD architecture, the vehicle longitudinal controller (VLC) and the controlled deceleration unit (CDD) work together to achieve more precise vehicle speed and acceleration control. The vehicle longitudinal controller (VLC) is responsible for high-level control decisions, while the controlled deceleration unit (CDD) is responsible for specific execution, such as calculating and applying braking force.

[0062] In summary, the braking control scheme for vehicles according to embodiments of this application introduces a first signal (which instructs the autonomous driving system to request the vehicle to stop) into the detection of the vehicle's expected stop. This detection is more accurate than existing schemes and can effectively bring the vehicle to a complete stop on various inclines. Furthermore, at least based on the vehicle's propulsion force Fx... prop The actual braking force Fx of the vehicle brake_act And the slope determines the anti-rollback braking force Fx rollout This fully takes into account the impact of different electronic control units (ECUs).

[0063] In one or more embodiments, the vehicle's expected stop is determined to be "true" when a first signal is received and the vehicle's actual speed is less than a first threshold. That is, if the vehicle's actual speed is greater than the first threshold, the expected stop is "false" even if the first signal (which instructs the autonomous driving system to request the vehicle to stop) is received. This embodiment avoids untimely braking actions while the vehicle is at high speed.

[0064] In one or more embodiments, the braking control scheme for a vehicle also limits the minimum braking force provided to the braking system, i.e., the anti-rollover braking force Fx. rollout With preset minimum braking force Fx min Compare the two and determine the smaller one (due to the anti-rollback braking force Fx). rollout With preset minimum braking force Fx min All values ​​are negative, so the smaller the value, the larger the absolute value. This information is provided to the Electronic Stability Program (ESP) or the Integrated Parking Brake (IPB) for braking. The purpose of this is to ensure that the vehicle remains safely stationary even under the most unfavorable slope conditions, and does not roll backward due to insufficient braking force.

[0065] The above examples primarily illustrate the braking control scheme for vehicles according to embodiments of this application. Although only some embodiments of this application have been described, those skilled in the art should understand that this application can be implemented in many other forms without departing from its spirit and scope. Therefore, the examples and embodiments shown are considered illustrative rather than restrictive, and various modifications and substitutions may be made without departing from the spirit and scope of this application as defined in the claims.

Claims

1. A braking control method for a vehicle, characterized in that, The method includes: Receive a first signal from the autonomous driving system, the first signal instructing the autonomous driving system to request that the vehicle be stopped; The expected stopping of the vehicle is determined based on the first signal and the actual speed of the vehicle; and When the stop expectation is determined to be "true", the anti-rollback braking force Fx is calculated during the receipt of the first signal. rollout The anti-rollback braking force Fx rollout At least according to the propulsion force Fx of the vehicle prop The actual braking force Fx of the vehicle brake_act The gradient is determined so that the vehicle can come to a complete stop on different slopes.

2. The method as described in claim 1, wherein, The first signal is a stationary request from the Adaptive Cruise Control (ACC) system.

3. The method as described in claim 1 or 2, wherein, Determining the expected stopping of the vehicle based on the first signal and the vehicle's actual speed includes: Upon receiving the first signal and when the actual speed of the vehicle is less than a first threshold, the expected stop of the vehicle is determined to be "true".

4. The method of claim 3, further comprising: The expected stopping of the vehicle is detected based on the ratio of the vehicle's actual speed to its deceleration.

5. The method of claim 4, wherein, When the ratio is less than the second threshold, the vehicle's expected stop is determined to be "true".

6. The method of claim 1, wherein, The anti-rollback braking force Fx rollout Determined according to the following formula: Fx rollout =m*a-Fx prop -Fx brake_act -Fx offset , Where m is the mass of the vehicle, a is the acceleration of the vehicle, and Fx rollout For the anti-rollback braking force, Fx prop The propulsion force of the vehicle, Fx brake_act The actual braking force of the vehicle and Fx offset The offset force is calculated based on the slope, and the parameter values ​​involved in the above formula are signed, being positive along the direction of vehicle travel and negative otherwise.

7. The method of claim 6, wherein, The anti-slipping braking force is negative, and the offset force is a preset offset amount based on the slope and is positive.

8. The method of claim 7, further comprising: The anti-backward slip braking force Fx rollout With preset minimum braking force Fx min The two are compared, and the smaller of the two is provided to the vehicle stability system ESP or the integrated parking brake IPB for braking, wherein the preset minimum braking force Fx min Determined based on the slope.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1 to 8.

10. A domain controller, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the method as described in any one of claims 1 to 8.

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