Vehicle braking method, device, electronic device, medium and automatic driving vehicle

Abstract

The present disclosure provides a vehicle braking method, device, electronic device, medium and autonomous driving vehicle, which relates to the field of artificial intelligence technology, especially to the field of autonomous driving. The specific implementation scheme is: according to the vehicle characteristic parameters, the total braking torque of the vehicle is determined; according to the total braking torque and the current speed of the vehicle, the first target torque of the electric braking system and the reference braking torque of the hydraulic braking system are determined; according to the reference braking torque, the target pressure of the hydraulic braking system is determined; wherein the actual braking torque corresponding to the target pressure is less than the reference braking torque; and the vehicle is braked according to the first target torque and the target pressure.

Description

Technical Field

[0001] The present disclosure relates to the field of artificial intelligence technology, and in particular to the field of autonomous driving. More specifically, the present disclosure provides a vehicle braking method, device, electronic device, storage medium, computer program product, and autonomous driving vehicle. Background Art

[0002] Autonomous vehicles can be equipped with a braking system to brake the vehicle. In actual driving, the user and the autonomous driving system share the brake actuator. Compared with manual driving, autonomous driving controls braking at a higher frequency and with a greater braking slope. When braking under autonomous driving control, vehicles are prone to problems such as trembling and sudden braking. Summary of the invention

[0003] The present disclosure provides a vehicle braking method, device, electronic device, storage medium, computer program product, and autonomous driving vehicle.

[0004] According to one aspect of the present disclosure, a vehicle braking method is provided, wherein the vehicle includes an electric braking system and a hydraulic braking system, and the method includes: determining a total braking torque of the vehicle based on vehicle characteristic parameters; determining a first target torque of the electric braking system and a reference braking torque of the hydraulic braking system based on the total braking torque and a current vehicle speed; determining a target pressure of the hydraulic braking system based on the reference braking torque; wherein an actual braking torque corresponding to the target pressure is less than the reference braking torque; and braking the vehicle based on the first target torque and the target pressure.

[0005] According to another aspect of the present disclosure, a vehicle braking device is provided, wherein the vehicle includes an electric braking system and a hydraulic braking system, and the device includes: a total torque determination module, a sub-torque determination module, a pressure determination module, and a braking module. The total torque determination module is used to determine the total braking torque of the vehicle according to the vehicle characteristic parameters; the sub-torque determination module is used to determine the first target torque of the electric braking system and the reference braking torque of the hydraulic braking system according to the total braking torque and the current vehicle speed; the pressure determination module is used to determine the target pressure of the hydraulic braking system according to the reference braking torque; wherein the actual braking torque corresponding to the target pressure is less than the reference braking torque; and the braking module is used to brake the vehicle according to the first target torque and the target pressure.

[0006] According to another aspect of the present disclosure, an electronic device is provided, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method provided by the present disclosure.

[0007] According to another aspect of the present disclosure, a non-transitory computer-readable storage medium storing computer instructions is provided, wherein the computer instructions are used to enable a computer to execute the method provided by the present disclosure.

[0008] According to another aspect of the present disclosure, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the method provided by the present disclosure is implemented.

[0009] According to another aspect of the present disclosure, an autonomous driving vehicle is provided, comprising an electric braking system, a hydraulic braking system and the above-mentioned electronic device.

[0010] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present disclosure.

[0012] Figure 1 is a schematic diagram of an application scenario of a vehicle braking method and device according to an embodiment of the present disclosure;

[0013] Figure 2 is a schematic flow chart of a vehicle braking method according to an embodiment of the present disclosure;

[0014] Figure 3A is a schematic flow chart of a vehicle braking method according to another embodiment of the present disclosure;

[0015] Figure 3B is a schematic diagram of a vehicle braking method according to an embodiment of the present disclosure;

[0016] Figure 4 is a schematic diagram of the braking force of a braking system according to an embodiment of the present disclosure;

[0017] Figure 5 is a schematic structural block diagram of a vehicle braking device according to an embodiment of the present disclosure; and

[0018] Figure 6 It is a structural block diagram of an electronic device used to implement the vehicle braking method of the embodiment of the present disclosure. DETAILED DESCRIPTION

[0019] The following is a description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, including various details of the embodiments of the present disclosure to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present disclosure. Similarly, for the sake of clarity and conciseness, descriptions of well-known functions and structures are omitted in the following description.

[0020] The braking system equipped in an autonomous driving vehicle may include a hydraulic braking system and an electric braking system. When the vehicle is traveling at a low speed, the hydraulic braking system can be relied upon more for braking the vehicle.

[0021] In actual driving, under some conditions that require higher control accuracy, such as when the driving goal is to drive forward 20 cm with an error of no more than 1 cm, compared to manual driving, automatic driving controls braking at a higher frequency and with a greater braking slope to achieve more precise vehicle control.

[0022] It should be noted that the hydraulic brake system is very likely to cause overshoot and over-braking when the frequency and amplitude exceed those of manual driving. The actual driving effect of the vehicle is similar to that of a user who quickly steps on and releases the brake pedal. The vehicle will experience problems such as braking tremors and sudden braking. Especially in low-speed conditions where hydraulic braking is mainly used, the vehicle frequently brakes, and the sense of frustration is obvious, affecting the riding experience.

[0023] The disclosed embodiment aims to propose a vehicle braking method, which adopts under-braking for the hydraulic braking system to avoid the frequent braking problem caused by overshoot of the hydraulic braking system, thereby improving riding comfort while ensuring the accuracy of autonomous driving.

[0024] The technical solution provided by the present disclosure will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Figure 1 It is a schematic diagram of an application scenario of a vehicle braking method and device according to an embodiment of the present disclosure.

[0026] It should be noted that Figure 1 What is shown is merely an example of a system architecture to which the embodiments of the present disclosure can be applied, in order to help those skilled in the art understand the technical content of the present disclosure, but it does not mean that the embodiments of the present disclosure cannot be used in other devices, systems, environments or scenarios.

[0027] like Figure 1 As shown, the scene 100 of this embodiment includes a server 110, a vehicle 120 traveling on a road, an obstacle 130, a communication base station 140 and a road traffic network, wherein the road traffic network may include roads (e.g., roads 151, 152, 153), and an intersection 154 formed by the intersection of roads. Figure 1 The arrow in the middle indicates the direction of travel on the road.

[0028] For example, in the scenario 100, the vehicle 120 traveling on the road may be an autonomous vehicle. The obstacle 130 may be a pedestrian or other vehicles around the autonomous vehicle. For example, the vehicle 120 may travel straight along the road 151 and pass through the intersection 154, and the obstacle 130 needs to travel from the road 153 to the intersection 154 and turn left to enter the road 152.

[0029] The vehicle 120 may be equipped with a braking system to achieve vehicle braking, and the braking system may include an electric braking system and a hydraulic braking system. The vehicle may also be equipped with an automatic driving system to achieve automatic driving. The vehicle 120 may upload data to the backend server through the communication base station 140. The server 110 may, for example, request data from the backend server through the network to obtain the data uploaded by the vehicle 120.

[0030] It should be noted that the vehicle braking method provided in the embodiment of the present disclosure can be performed by the vehicle 120. Accordingly, the vehicle braking provided in the embodiment of the present disclosure can be arranged in the vehicle 120. The vehicle braking method provided in the embodiment of the present disclosure can also be performed by the server 110, and accordingly, the vehicle braking device provided in the embodiment of the present disclosure can also be arranged in the server 110.

[0031] It should be understood that Figure 1 The number and type of servers, roads, vehicles, obstacles and communication base stations in the embodiment are only for illustration. Any number and type of servers, roads, vehicles, obstacles and communication base stations may be provided as required.

[0032] Figure 2 is a schematic flow chart of a vehicle braking method according to an embodiment of the present disclosure.

[0033] like Figure 2 As shown, the vehicle braking method 200 can be applied to a vehicle, and the vehicle can be an autonomous driving vehicle or a non-autonomous driving vehicle. The vehicle includes a braking system, and the braking system can include an electric braking system and a hydraulic braking system. The device for executing the method 200 can be integrated into a controller of the electric braking system or a controller of the hydraulic braking system, and can also be integrated into other electronic devices other than the electric braking system and the hydraulic braking system. The method 200 can include operations S210 to S240.

[0034] In operation S210 , a total braking torque of a vehicle is determined based on a vehicle characteristic parameter.

[0035] For example, the vehicle characteristic parameters may include target deceleration, vehicle weight, etc. For example, for an autonomous driving vehicle, the target deceleration may be planned by the autonomous driving algorithm for each trajectory point in the driving trajectory to obtain the vehicle characteristic parameters such as speed and acceleration of each trajectory point.

[0036] For example, the total braking torque represents the torque required to brake the vehicle so that the deceleration of the vehicle when it travels to the target position is the target deceleration. The embodiment of the present disclosure does not limit the formula for determining the total braking torque.

[0037] In operation S220, a first target torque of the electric brake system and a reference brake torque of the hydraulic brake system are determined according to the total brake torque and the current speed of the vehicle.

[0038] For example, a first target torque may be allocated to the electric brake system, and a reference hydraulic torque may be allocated to the hydraulic brake system, and the sum of the first target torque and the reference hydraulic torque may be equal to the total brake torque.

[0039] For example, a correspondence between vehicle speed and torque distribution ratio may be established in advance, and then based on the correspondence, the total braking torque may be distributed according to the torque distribution ratio corresponding to the current vehicle speed, thereby obtaining a first target torque and a reference hydraulic torque.

[0040] In operation S230, a target pressure of the hydraulic brake system is determined according to the reference braking torque; wherein the braking torque corresponding to the target pressure is smaller than the reference braking torque.

[0041] For example, the reference pressure corresponding to the reference braking torque may be derived using the reference braking torque according to various parameters of the hydraulic braking system.

[0042] Next, for example, the reference pressure can be reduced according to a predetermined ratio to obtain a target pressure, for example, the product of the reference pressure and the predetermined ratio is used as the target pressure, and the numerical range of the predetermined ratio can be 0.85 to 9.95, for example, the predetermined ratio is 0.9. For another example, the difference between the reference pressure and the predetermined pressure margin can be used as the target pressure, for example, the numerical range of the predetermined pressure margin can be 0.01 to 0.1 bar. It can be seen that since the braking torque corresponding to the target pressure is less than the reference braking torque, the hydraulic braking system adopts an under-braking braking method.

[0043] It should be noted that in actual applications, under-braking can be used for high-speed, medium-speed, and low-speed driving conditions, or under-braking can be used only for some conditions (such as low-speed driving conditions), and normal braking can be used for other conditions (such as high-speed driving conditions). Normal braking here can mean that the braking torque corresponding to the target pressure is equal to the reference braking torque. It is understandable that the dividing line between high-speed driving conditions and low-speed driving conditions can be determined according to actual needs, for example, 50kph is used as the boundary between medium speed and high speed.

[0044] In operation S240, the vehicle is braked according to the first target torque and the target pressure.

[0045] For example, a first instruction is output to the electric brake system so that the electric brake system brakes according to the first target torque, and a second instruction is output to the hydraulic brake system so that the electric brake system brakes according to the target pressure.

[0046] The disclosed embodiment determines the target pressure of the hydraulic braking system according to the reference braking torque, and the braking torque corresponding to the target pressure is less than the reference braking torque, so that the hydraulic braking system brakes the vehicle in an under-braking manner, thereby reducing frequent braking caused by overshoot of the hydraulic braking system.

[0047] For example, the reference pressure corresponding to the reference braking torque of the hydraulic brake system is 10 bar. During the control process, the target pressure of the hydraulic brake system may be 9 bar. Then, during the execution process, an overshoot of 9 bar occurs, that is, the pressure actually executed by the hydraulic brake system is greater than 9 bar. However, since the overshoot is small, the pressure after the overshoot is equal to 10 bar or close to 10 bar, thereby alleviating the frequent braking problem caused by the overshoot. And since the target pressure after the overshoot is close to the reference pressure, the accuracy of the vehicle's driving position can be ensured.

[0048] It should be noted that the longitudinal control of autonomous driving may include closed-loop control of speed and position. The difference between the reference pressure and the target pressure is the hydraulic under-braking part, which can be supplemented by increasing the braking request in the next control cycle. However, in the case of under-braking, the target pressure requested for the hydraulic braking system in each control cycle is less than the reference pressure corresponding to the reference braking torque. For example, in the current control cycle, the reference pressure corresponding to the reference braking torque is 10 bar, the target pressure requested for the hydraulic braking system is 9 bar, the reference pressure for the next control cycle may be 20 bar, and the target pressure of the hydraulic braking system is actually requested to be 18 bar. When braking overshoot occurs due to too fast a request, the hydraulic braking actually performed will not significantly exceed the reference pressure, thereby alleviating the problem of control oscillation.

[0049] Figure 3Ais a schematic flow chart of a vehicle braking method according to another embodiment of the present disclosure, Figure 3B is a schematic diagram of a vehicle braking method according to an embodiment of the present disclosure

[0050] The following combination Figure 3A and Figure 3B , the vehicle braking method in this embodiment is described, and the method may include the following operations:

[0051] In operation S310 , a total braking torque of a vehicle is determined based on a vehicle characteristic parameter.

[0052] In operation S320, a first target torque of the electric brake system and a reference brake torque of the hydraulic brake system are determined according to the total brake torque and the current speed of the vehicle.

[0053] In operation S331, in response to detecting that the reference braking torque is greater than 0 and the current vehicle speed is less than or equal to the first predetermined vehicle speed, a target pressure of the hydraulic brake system is determined according to the reference braking torque, and the braking torque corresponding to the target pressure is less than the reference braking torque.

[0054] In operation S350, in response to detecting that the reference braking torque is greater than 0 and the current vehicle speed is greater than a first predetermined vehicle speed, a target pressure of the hydraulic brake system is determined according to the reference braking torque, and a braking torque corresponding to the target pressure is equal to the reference braking torque.

[0055] In operation S340, the vehicle is braked according to the first target torque and the target pressure.

[0056] For example, a speed threshold may be preset, and then the speed interval of the current vehicle speed is determined based on the speed threshold, and the first target torque of the electric brake system and the reference braking torque of the hydraulic brake system are determined according to the speed interval. For example, the speed threshold may include a first predetermined speed and a second predetermined speed, the first predetermined speed may be 20 kph, the second predetermined speed is less than the first predetermined speed, and the second predetermined speed may be 5 kph.

[0057] It should be noted that the speed threshold can be used to distinguish the current operating condition of the vehicle. For example, if the current speed of the vehicle is greater than or equal to the first predetermined speed, it indicates that the vehicle is in a high-speed driving condition; if the current speed of the vehicle is greater than or equal to the second predetermined speed and less than or equal to the first predetermined speed, it indicates that the vehicle is in a medium-speed driving condition; if the current speed of the vehicle is less than the first predetermined speed, it indicates that the vehicle is in a low-speed driving condition.

[0058] It should be noted that a vehicle in a high-speed driving condition may indicate that there is no obstacle ahead or the vehicle is far from the obstacle. Correspondingly, a vehicle in a medium-low speed driving condition may indicate that there is an obstacle ahead, the vehicle is behind the obstacle and is following the vehicle, and the distance between the vehicle and the obstacle is small.

[0059] It should be noted that the vehicle uses a time-distance parameter during the process of autonomous driving. The time-distance parameter can represent the time taken by the vehicle to reach a certain position. The vehicle speed is negatively correlated with the control accuracy requirements of the vehicle position by autonomous driving. For example, when the vehicle speed is 10kph, the control accuracy requirement can be that the vehicle reaches a certain target position in the next second and the allowable error can be less than a dozen centimeters or even a few centimeters to ensure the accuracy of following and parking and avoid rear-end collisions. When the vehicle speed is 100kph, the vehicle is required to reach a certain target position in the next second and the allowable error can be less than a few meters or even more than ten meters.

[0060] It should be noted that when the current vehicle speed is less than the first predetermined vehicle speed, the motor is blocked due to the characteristics of the motor itself in the electric brake system, and the low-speed electric braking capacity approaches 0. Therefore, hydraulic braking is preferably used at low speeds to ensure the braking effect. Since the automatic driving control has high requirements for position error under medium and low speed driving conditions, which leads to high requirements for braking execution accuracy, more frequent braking adjustment is required. Therefore, the hydraulic braking system is more prone to overshoot under medium and low speed driving conditions. This embodiment adopts an under-braking scheme for medium and low speed driving conditions. For example, when the pressure corresponding to the reference braking torque is 10 bar, the hydraulic braking system is only requested to execute a pressure of 9 bar to ensure driving stability.

[0061] In addition, when the current vehicle speed is greater than the first predetermined vehicle speed, the hydraulic braking system may adopt normal braking to ensure timely and effective braking effects, or the hydraulic braking system may adopt under-braking.

[0062] The following describes a method for determining the first target torque of the electric brake system and the reference brake torque of the hydraulic brake system in combination with the current vehicle speed.

[0063] In one example, the current speed of the vehicle is less than the second predetermined speed. In this case, the first target torque can be determined to be 0, and the total braking torque can be determined as the reference braking torque. It can be seen that only hydraulic braking can be used when driving at low speeds without using electric braking. Compared with electric braking, hydraulic braking has higher braking efficiency.

[0064] In another example, the current speed of the vehicle is greater than or equal to the second predetermined speed. In this case, the electric brake system can monitor its current available torque in real time, and transmit the current available torque to the vehicle brake device through the CAN bus, and the vehicle brake device can determine the smaller of the current available torque of the electric brake system and the total braking torque as the first target torque. The vehicle brake device also determines the reference braking torque according to the total braking torque and the first target torque.

[0065] like Figure 3B As shown, it can be seen that when the current vehicle speed is greater than or equal to the second predetermined speed, the braking process includes the following two situations.

[0066] When the current available electric braking torque of the electric braking system is greater than or equal to the total braking torque, the total braking torque required for vehicle braking is provided by the electric braking system. In this case, only the electric braking system is used for vehicle braking, the first target torque of the electric braking system is equal to the total braking torque required for vehicle braking, and the target pressure of the hydraulic braking system can be 0.

[0067] When the current available electric braking torque of the electric braking system is less than the total braking torque, the electric braking system provides the current available electric braking torque for braking, and the insufficient torque is provided by the hydraulic braking system. In this case, the electric braking system and the hydraulic braking system are used to brake the vehicle, the first target torque of the electric braking system is equal to the current available electric braking torque, and the reference braking torque provided by the hydraulic braking system is equal to the difference between the total braking torque of the vehicle and the current available electric braking torque of the electric braking system. For example, the total braking torque is 100Nm, at this time the current available torque of the motor in the electric braking system is 50Nm, the first target torque of the electric braking system is 50Nm, and the reference braking torque of the hydraulic braking system is 50Nm. The target pressure of the hydraulic braking system can be obtained from the reference braking torque, for example, the target pressure is 9bar.

[0068] It can be seen that when the current speed of the vehicle is greater than or equal to the second predetermined speed, the electric brake system is used for braking first, and the braking effect is improved by giving priority to the electric brake with better braking performance.

[0069] In practical applications, the electric brake system can adopt a closed-loop control strategy, for example, the real-time execution torque of the electric brake system can be determined, and the real-time execution torque represents the braking force that the electric brake system has executed. For example, the available torque of the electric brake system is 50Nm, and the electric brake system is requested to execute a torque of 40Nm at a certain moment in the past. At the current moment, the electric brake system has executed 38Nm, and the 38Nm is the real-time execution torque. After obtaining the real-time execution torque, it can be determined whether the real-time execution torque reaches the first target torque. If it reaches, the electric brake system can be controlled to stop braking. If it does not reach, the electric brake system can be controlled to continue braking.

[0070] Figure 4 is a schematic diagram of the braking force of a braking system according to an embodiment of the present disclosure;

[0071] The following combination Figure 4 , the braking principle in this embodiment is explained.

[0072] like Figure 4As shown, the abscissa in the figure represents the vehicle speed, and the ordinate represents the maximum available braking force of the electric brake system and the hydraulic brake system. In this embodiment, the speed interval is divided into three sub-intervals by the first predetermined vehicle speed v_th1 and the second predetermined vehicle speed v_th2. Figure 4 4 shows an electric braking area and a hydraulic braking area, and a gap between the two areas is an under-braking portion 401 of the hydraulic brake.

[0073] If the current vehicle speed v is less than the second predetermined vehicle speed v_th2, only the hydraulic brake system may be used for braking, and the hydraulic brake system adopts under-braking.

[0074] If the current vehicle speed v is greater than or equal to the second predetermined vehicle speed v_th2 and less than or equal to the first predetermined vehicle speed v_th1, electric braking is preferred. If the current available torque that the electric braking system can provide is less than the total braking torque, the insufficient torque is provided by the hydraulic braking system. In this case, the hydraulic braking system can use under braking.

[0075] If the current vehicle speed v is greater than the first predetermined vehicle speed v_th1, electric braking is preferred. If the torque provided by the electric braking system is less than the total braking torque, the insufficient torque is provided by the hydraulic braking system. In this case, the hydraulic braking system can use under braking or normal braking.

[0076] This embodiment adopts a combined braking scheme of electric braking and hydraulic braking, and the hydraulic braking in medium and low speed conditions adopts under-braking to optimize the execution characteristics of the hydraulic braking, thereby ensuring braking performance with similar execution characteristics in each vehicle speed range.

[0077] It should be noted that, in some cases, as the vehicle speed increases, the hydraulic braking force that needs to be compensated may decrease accordingly, and the hydraulic braking force that needs to be compensated represents the difference between the total braking torque and the electric braking torque. Accordingly, the smaller the under-braking part 401 is, the under-braking part 401 can represent the difference between the braking force generated by the target pressure and the reference braking force during the under-braking process of the hydraulic braking system. For example, when the current vehicle speed v is less than the second predetermined vehicle speed v_th2, the braking force of the under-braking part 401 is the largest. For example, when the current vehicle speed v is equal to the first predetermined vehicle speed v_th1, the reference pressure of the hydraulic braking system may be 10 bar, and a target pressure of 9 bar may be requested when actually requested. At this time, the pressure of the under-braking part 401 is 1 bar, so the gap between the hydraulic braking area and the electric braking area in the figure is large. For example, when the current vehicle speed v is close to the second predetermined vehicle speed v_th2, the reference pressure of the hydraulic braking system is 1 bar, and a target pressure of 0.9 bar may be requested when actually requested. At this time, the pressure of the under-braking part 401 is 0.1 bar, so the gap between the hydraulic braking area and the electric braking area in the figure is small.

[0078] According to another embodiment of the present disclosure, the above-mentioned operation of determining the target pressure of the hydraulic braking system according to the reference braking torque may include the following operation: determining the target pressure of the hydraulic braking system according to the reference braking torque, the target under-braking coefficient and the target conversion coefficient.

[0079] For example, the target conversion coefficient represents the relationship between the braking torque of the electric brake system and the pressure of the hydraulic brake system when the wheel end torque of the vehicle is consistent. Calibration can be performed in advance to obtain the target conversion coefficient. The calibration process is described below.

[0080] For example, a vehicle is traveling at a fixed speed (e.g., 30 kph) on a fixed road section, and the calibrated object is a torque of 100 Nm. When the motor controller in the electric brake system reports that 100 Nm has been executed, the deceleration at this time is obtained as, for example, -1 m / s. 2 Next, the vehicle was driven at a speed of 30 kph on the fixed road section, without using the electric brake system and only braking with hydraulic pressures of different pressures. When the deceleration was -1 m / s 2 When the hydraulic pressure at this time is obtained, for example, 10 bar, the conversion coefficient between 100 Nm of the electric brake system and 10 bar of the hydraulic brake system can be established as 0.1. The torque of the motor in the electric brake system corresponding to each pressure of the hydraulic brake system can be obtained in the above manner. After obtaining the conversion coefficient, the equivalent conversion between electric brake and hydraulic brake can be performed.

[0081] During under-braking, the product of the above conversion coefficient and the target under-braking coefficient can be used as the target conversion coefficient used, and the target under-braking coefficient is less than 1. During normal braking, the above conversion coefficient can be used as the target conversion coefficient used. For example, when the reference braking torque is 100Nm, the target conversion coefficient for under-braking can be 0.09, and the target conversion coefficient for normal braking can be 0.1. Next, based on the target conversion coefficient, the reference braking torque can be converted into the corresponding target pressure.

[0082] The disclosed embodiment determines the target pressure through a pre-calibrated target conversion coefficient, without the need to derive the required target pressure based on the reference braking torque according to various parameters of the hydraulic brake system, thereby improving data processing efficiency and ensuring the timeliness of braking.

[0083] According to another embodiment of the present disclosure, the above-mentioned operation of determining the target pressure of the hydraulic braking system based on the baseline braking torque may include the following operations: determining the second target torque of the hydraulic braking system based on the baseline braking torque and the target under-braking coefficient, and then determining the target pressure based on the second target torque.

[0084] For example, the product of the reference braking torque and the target under-braking coefficient may be used as the second target torque, and the target under-braking coefficient is less than 1. Then, the reference pressure corresponding to the reference braking torque may be derived using the second target torque according to various parameters of the hydraulic brake system.

[0085] In this embodiment, the reference braking torque is reduced by the target under-braking coefficient to obtain the second target torque, and then the target pressure is determined by using the second target torque, so that the target pressure required by the hydraulic brake system can be accurately obtained.

[0086] Figure 5 It is a schematic structural block diagram of a vehicle braking device according to an embodiment of the present disclosure.

[0087] like Figure 5 As shown, the vehicle braking device 500 includes an electric braking system and a hydraulic braking system, and the device 500 includes: a total torque determination module 510, a sub-torque determination module 520, a pressure determination module 530 and a braking module 540.

[0088] The total torque determination module 510 is used to determine the total braking torque of the vehicle according to the vehicle characteristic parameters.

[0089] The sub-torque determination module 520 is used to determine a first target torque of the electric brake system and a reference brake torque of the hydraulic brake system according to the total brake torque and the current vehicle speed.

[0090] The pressure determination module 530 is used to determine a target pressure of the hydraulic brake system according to a reference braking torque, wherein an actual braking torque corresponding to the target pressure is less than the reference braking torque.

[0091] The braking module 540 is configured to brake the vehicle according to the first target torque and the target pressure.

[0092] According to another embodiment of the present disclosure, the pressure determination module is further configured to determine a target pressure of the hydraulic brake system according to a reference braking torque in response to detecting that a current vehicle speed is less than or equal to a first predetermined vehicle speed.

[0093] According to another embodiment of the present disclosure, the sub-torque determination module includes: a first determination sub-module and a second determination sub-module. The first determination sub-module is used to determine that the first target torque is 0 and the second predetermined vehicle speed is less than the first predetermined vehicle speed in response to detecting that the current vehicle speed is less than the second predetermined vehicle speed. The second determination sub-module is used to determine the total braking torque as the reference braking torque.

[0094] According to another embodiment of the present disclosure, the sub-torque determination module includes: a third determination sub-module, a fourth determination sub-module and a fifth determination sub-module. The third determination sub-module is used to obtain the current available torque of the electric brake system in response to detecting that the current vehicle speed is greater than or equal to the second predetermined vehicle speed. The fourth determination sub-module is used to determine the smaller value of the current available torque and the total braking torque as the first target torque. The fifth determination sub-module is used to determine the reference braking torque based on the total braking torque and the first target torque.

[0095] According to another embodiment of the present disclosure, the pressure determination module includes: a sixth determination submodule is used to determine the target pressure of the hydraulic brake system according to the reference braking torque, the target under-braking coefficient and the target conversion coefficient. Wherein, the target conversion coefficient represents the relationship between the braking torque of the electric brake system and the pressure of the hydraulic brake system when the wheel-end torque of the vehicle is consistent. The target under-braking coefficient is less than 1.

[0096] According to another embodiment of the present disclosure, the pressure determination module includes: a seventh determination submodule and an eighth determination submodule. The seventh determination submodule is used to determine a second target torque of the hydraulic brake system according to a reference braking torque and a target under-braking coefficient. The target under-braking coefficient is less than 1. The eighth determination submodule is used to determine a target pressure according to the second target torque.

[0097] In the technical solution of the present disclosure, the collection, storage, use, processing, transmission, provision and disclosure of user personal information involved are in compliance with the provisions of relevant laws and regulations and do not violate public order and good morals.

[0098] In the technical solution of the present disclosure, the user's authorization or consent is obtained before obtaining or collecting the user's personal information.

[0099] According to an embodiment of the present disclosure, the present disclosure also provides an electronic device, comprising at least one processor; and a memory communicatively connected to the at least one processor; the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the above-mentioned vehicle braking method.

[0100] According to an embodiment of the present disclosure, the present disclosure also provides a non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to enable a computer to execute the above-mentioned vehicle braking method.

[0101] According to an embodiment of the present disclosure, the present disclosure also provides a computer program product, including a computer program, and the computer program implements the above-mentioned vehicle braking method when executed by a processor.

[0102] Figure 6 It is a structural block diagram of an electronic device used to implement the vehicle braking method of the embodiment of the present disclosure.

[0103] Electronic devices are intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframes, and other suitable computers. Electronic devices may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present disclosure described and / or claimed herein.

[0104] like Figure 6 As shown, the device 600 includes a computing unit 601, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 602 or a computer program loaded from a storage unit 608 into a random access memory (RAM) 603. In the RAM 603, various programs and data required for the operation of the device 600 can also be stored. The computing unit 601, the ROM 602, and the RAM 603 are connected to each other via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0105] A number of components in the device 600 are connected to the I / O interface 605, including: an input unit 606, such as a keyboard, a mouse, etc.; an output unit 607, such as various types of displays, speakers, etc.; a storage unit 608, such as a disk, an optical disk, etc.; and a communication unit 609, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 609 allows the device 600 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0106] The computing unit 601 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 601 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 601 performs the various methods and processes described above, such as a vehicle braking method. For example, in some embodiments, the vehicle braking method may be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as a storage unit 608. In some embodiments, part or all of the computer program may be loaded and / or installed on the device 600 via ROM 602 and / or communication unit 609. When the computer program is loaded into RAM 603 and executed by the computing unit 601, one or more steps of the vehicle braking method described above may be performed. Alternatively, in other embodiments, the computing unit 601 may be configured to perform the vehicle braking method in any other appropriate manner (e.g., by means of firmware).

[0107] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0108] The program code for implementing the method of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0109] In the context of the present disclosure, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or equipment, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer 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 foregoing.

[0110] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0111] The systems and techniques described herein may be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), and the Internet.

[0112] A computer system may include clients and servers. Clients and servers are generally remote from each other and usually interact through a communication network. The relationship of client and server is generated by computer programs running on respective computers and having a client-server relationship to each other.

[0113] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and this document does not limit this.

[0114] The above specific implementations do not constitute a limitation on the protection scope of the present disclosure. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A vehicle braking method, wherein the vehicle includes an electric braking system and a hydraulic braking system, the method comprising: Determining the total braking torque of the vehicle according to the vehicle characteristic parameters; determining a first target torque of the electric brake system and a reference brake torque of the hydraulic brake system according to the total brake torque and a current vehicle speed of the vehicle; Determining a target pressure of the hydraulic brake system according to the reference braking torque; wherein an actual braking torque corresponding to the target pressure is less than the reference braking torque; and braking the vehicle according to the first target torque and the target pressure; When the current vehicle speed is less than or equal to the first predetermined vehicle speed and greater than or equal to the second predetermined vehicle speed, the under-braking amount is negatively correlated with the current vehicle speed, and the under-braking amount represents the difference between the actual braking torque generated by the target pressure and the reference braking torque.

2. The method according to claim 1, wherein: In response to detecting that the current vehicle speed is less than or equal to a first predetermined vehicle speed, a target pressure of the hydraulic brake system is determined according to the reference braking torque.

3. The method according to claim 2, wherein: Determining the first target torque of the electric brake system and the reference brake torque of the hydraulic brake system according to the total brake torque and the current speed of the vehicle comprises: In response to detecting that the current vehicle speed is less than a second predetermined vehicle speed, determining that the first target torque is 0; the second predetermined vehicle speed is less than the first predetermined vehicle speed; and The total braking torque is determined as the reference braking torque.

4. The method according to claim 2, wherein: Determining the first target torque of the electric brake system and the reference brake torque of the hydraulic brake system according to the total brake torque and the current speed of the vehicle comprises: In response to detecting that the current vehicle speed is greater than or equal to a second predetermined vehicle speed, obtaining a current available torque of the electric brake system; determining a smaller value between the current available torque and the total braking torque as the first target torque; and The reference braking torque is determined according to the total braking torque and the first target torque.

5. The method according to any one of claims 1 to 4, wherein: Determining the target pressure of the hydraulic brake system according to the reference braking torque comprises: determining a target pressure of the hydraulic brake system according to the reference braking torque, the target under-braking coefficient and the target conversion coefficient; The target conversion coefficient represents the relationship between the braking torque of the electric braking system and the pressure of the hydraulic braking system when the wheel end torque of the vehicle is consistent; and the target under-braking coefficient is less than 1.

6. The method according to any one of claims 1 to 4, wherein: Determining the target pressure of the hydraulic brake system according to the reference braking torque comprises: determining a second target torque of the hydraulic brake system according to the reference braking torque and a target under-braking coefficient; wherein the target under-braking coefficient is less than 1; and The target pressure is determined according to the second target torque.

7. A vehicle braking device, the vehicle comprising an electric braking system and a hydraulic braking system, the device comprising: A total torque determination module, used for determining the total braking torque of the vehicle according to vehicle characteristic parameters; a sub-torque determination module, configured to determine a first target torque of the electric brake system and a reference brake torque of the hydraulic brake system according to the total brake torque and a current vehicle speed of the vehicle; a pressure determination module, configured to determine a target pressure of the hydraulic brake system according to the reference braking torque; wherein an actual braking torque corresponding to the target pressure is less than the reference braking torque; and a braking module, configured to brake the vehicle according to the first target torque and the target pressure; When the current vehicle speed is less than or equal to the first predetermined vehicle speed and greater than or equal to the second predetermined vehicle speed, the under-braking amount is negatively correlated with the current vehicle speed, and the under-braking amount represents the difference between the actual braking torque generated by the target pressure and the reference braking torque.

8. The device according to claim 7, wherein: The pressure determination module is further configured to determine a target pressure of the hydraulic brake system according to the reference braking torque in response to detecting that the current vehicle speed is less than or equal to a first predetermined vehicle speed.

9. The device according to claim 8, wherein: The sub-torque determination module comprises: A first determination submodule is configured to determine that the first target torque is 0 in response to detecting that the current vehicle speed is less than a second predetermined vehicle speed; the second predetermined vehicle speed is less than the first predetermined vehicle speed; and The second determining submodule is configured to determine the total braking torque as the reference braking torque.

10. The device according to claim 8, wherein: The sub-torque determination module comprises: a third determination submodule, configured to obtain a current available torque of the electric brake system in response to detecting that the current vehicle speed is greater than or equal to a second predetermined vehicle speed; a fourth determination submodule, configured to determine a smaller value between the current available torque and the total braking torque as the first target torque; and The fifth determining submodule is configured to determine the reference braking torque according to the total braking torque and the first target torque.

11. The device according to any one of claims 7 to 10, wherein: The pressure determination module comprises: a sixth determination submodule, configured to determine a target pressure of the hydraulic brake system according to the reference braking torque, the target under-braking coefficient and the target conversion coefficient; The target conversion coefficient represents the relationship between the braking torque of the electric braking system and the pressure of the hydraulic braking system when the wheel end torque of the vehicle is consistent; and the target under-braking coefficient is less than 1.

12. The device according to any one of claims 7 to 10, wherein: The pressure determination module comprises: a seventh determination submodule, configured to determine a second target torque of the hydraulic brake system according to the reference braking torque and a target under-braking coefficient; wherein the target under-braking coefficient is less than 1; and An eighth determination submodule is configured to determine the target pressure according to the second target torque.

13. An electronic device, comprising: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 6.

14. A non-transitory computer-readable storage medium storing computer instructions, wherein: The computer instructions are used to cause the computer to execute the method according to any one of claims 1 to 6.

15. A computer program product comprising a computer program, which, when executed by a processor, implements the method according to any one of claims 1 to 6.

16. An autonomous driving vehicle, comprising: Electric brake system; Hydraulic brake system; as well as The electronic device according to claim 13.

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