Braking control method, device, equipment and storage medium for unmanned vehicle

Abstract

The present invention relates to the technical field of brake control for unmanned vehicles, and discloses a brake control method, apparatus, equipment, and storage medium for unmanned vehicles, which are used to reduce the risk of frequent brake failure of hydraulic brake actuators, improve energy recovery, and make hydraulic braking and electric braking redundant and complementary to each other to meet braking needs in special circumstances and ensure the smoothness of the brake mode switching process. The brake control method for an unmanned vehicle includes: obtaining a first actual state parameter and a target negative acceleration of the vehicle, the first actual state parameter including at least a first driving speed; calculating a total braking demand based on the target negative acceleration and a preset brake table, the total braking demand including a target brake opening; performing brake distribution based on the first driving speed and the total braking demand to obtain a first target braking mode and a first target braking command value; and performing brake control based on the first target braking mode and the first target braking command value.

Description

Technical Field

[0001] The present invention relates to the technical field of brake control for unmanned vehicles, and in particular to a brake control method, device, equipment and storage medium for an unmanned vehicle. Background Art

[0002] Unmanned driving or automatic driving is the development trend of the automotive industry. Most unmanned vehicles are new energy vehicles such as pure electric vehicles and hybrid vehicles. Their braking system plays a vital role in the operation and safety of the vehicle. The wire control braking system used in unmanned driving often includes two modes: hydraulic braking and electric braking. In order to improve the cruising range of new energy vehicles, the negative torque generated by the reverse drag or reversal of the motor is generally recovered during braking to avoid direct friction being converted into heat energy. That is, electric braking can recover energy, while hydraulic braking consumes energy.

[0003] Compared to traditional manual driving, advanced assisted driving and even more advanced autonomous driving require braking systems capable of rapid, active pressure application and precise pressure control to achieve appropriate acceleration. This allows for precise deceleration control when the acceleration is negative, ensuring the vehicle follows the planned trajectory. Currently, the algorithm-controlled negative acceleration of autonomous vehicle brake-by-wire systems typically maintains an error of no more than 0.3 m / s². This accuracy is typically achieved by issuing braking commands at a high frequency or continuously for a long period of time.

[0004] In situations where autonomous driving requires frequent or prolonged braking commands, the traditional manual braking system, which uses hydraulic braking as the primary braking mode, may experience failure in the hydraulic brake pressure buildup due to prolonged hydraulic reflux or frequent pressure buildup, leading to brake failure and making it difficult to meet the durability and stability requirements of braking in the highly automated driving stage. Braking systems that use electric braking as the primary braking mode offer higher durability, stability, and braking smoothness than hydraulic braking, but their maximum braking force is difficult to meet the needs of autonomous driving. During hybrid braking, switching between electric and hydraulic braking can cause sudden braking changes and delays, impacting the driving experience. Existing technologies generally use parallel control of hydraulic and electric braking, with the energy consumed by hydraulic braking exceeding the energy recovered by electric braking. This results in a low overall braking energy recovery rate, which is detrimental to improving the range of new energy vehicles. Summary of the Invention

[0005] The present invention provides a brake control method, device, equipment and storage medium for an unmanned vehicle, which are used to reduce the risk of frequent brake failure of a hydraulic brake actuator and extend its service life.

[0006] A first aspect of the present invention provides a braking control method for an unmanned vehicle, comprising: obtaining a first actual state parameter and a target negative acceleration of the vehicle, the first actual state parameter including at least a first driving speed; calculating a total braking demand based on the target negative acceleration and a preset brake table, the total braking demand including a target brake opening; performing braking distribution based on the first driving speed and the total braking demand to obtain a first target braking mode and a first target braking command value, the first target braking mode being used to indicate the execution of electric braking and / or hydraulic braking; and performing braking control based on the first target braking mode and the first target braking command value.

[0007] A second aspect of the present invention provides a braking control device for an unmanned vehicle, comprising: a first acquisition module for acquiring a first actual state parameter and a target negative acceleration of the vehicle, the first actual state parameter including at least a first driving speed; a calculation module for calculating a total braking demand based on the target negative acceleration and a preset braking table, the total braking demand including a target brake opening; a distribution module for performing braking distribution based on the first driving speed and the total braking demand, and obtaining a first target braking mode and a first target braking command value, the first target braking mode being used to indicate the execution of electric braking and / or hydraulic braking; and a braking module for performing braking control based on the first target braking mode and the first target braking command value.

[0008] A third aspect of the present invention provides a braking control device for an unmanned vehicle, comprising: a memory and at least one processor, wherein instructions are stored in the memory; at least one processor calls the instructions in the memory so that the braking control device of the unmanned vehicle executes the above-mentioned braking control method for the unmanned vehicle.

[0009] A fourth aspect of the present invention provides a computer-readable storage medium, in which instructions are stored. When the computer-readable storage medium is run on a computer, the computer executes the above-mentioned braking control method for an unmanned vehicle.

[0010] The technical solution provided by the present invention can automatically distribute electric braking and hydraulic braking, and use electric braking as the main braking method for unmanned driving, which reduces the frequency of use of hydraulic brake actuators, reduces the risk of frequent braking failure of hydraulic brake actuators, extends the service life of hydraulic brake actuators, and ensures the stability of vehicles during braking; using electric braking as the main method can improve the energy recovery rate, thereby extending the cruising range of new energy vehicles; electric braking uses torque to control acceleration, which is smoother than the cylinder pressure control acceleration of hydraulic braking, and the braking capacity of hydraulic braking is stronger than electric braking. Combining the advantages of the two, hydraulic braking is used as a backup and compensatory redundant braking, which reduces the cost of wire control, meets the braking needs in various situations, and takes into account the safety, economy and driving comfort of the unmanned vehicle during driving.

[0011] In the technical solution provided by the present invention, the brake table is obtained and regularly corrected through the cloud, which solves the problems of brake mutation and delay that occur during the switching process between electric braking mode and hydraulic braking mode, ensures the smoothness of brake mode switching, and improves the accuracy of brake control. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A schematic diagram of an embodiment of a braking control method for an unmanned vehicle according to an embodiment of the present invention;

[0013] Figure 2 Schematic diagram of another embodiment of a braking control method for an unmanned vehicle according to an embodiment of the present invention;

[0014] Figure 3 Schematic diagram of a braking control device for an unmanned vehicle according to an embodiment of the present invention;

[0015] Figure 4 Schematic diagram of another embodiment of a brake control device for an unmanned vehicle according to an embodiment of the present invention;

[0016] Figure 5 FIG. 1 is a schematic diagram of an embodiment of a brake control device for an unmanned vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The present invention provides a braking control method, device, equipment and storage medium for unmanned vehicles, which are used to reduce the risk of frequent braking failure of hydraulic brake actuators and extend their service life; use electric braking as the main braking method to improve the energy recovery rate and extend the cruising range of new energy vehicles; and use hydraulic braking as a backup and compensatory redundant braking to meet braking needs in special circumstances.

[0018] The terms "first," "second," "third," "fourth," and the like (if any) in the description and claims of the present invention and in the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" or "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to these processes, methods, products, or apparatus.

[0019] For ease of understanding, the specific process of the embodiment of the present invention is described below. Figure 1An embodiment of a braking control method for an unmanned vehicle according to an embodiment of the present invention includes:

[0020] 101. Obtain a first actual state parameter and a target negative acceleration of a vehicle, where the first actual state parameter includes at least a first driving speed.

[0021] It is understood that the execution entity of the present invention can be a brake control device for an unmanned vehicle, a vehicle terminal, or a server, without limitation. When a server is used as the execution entity, the vehicle terminal can be remotely controlled to perform braking. Furthermore, through a collaborative control algorithm, the server can control multiple vehicle terminals to perform coordinated braking based on the present invention. The embodiments of the present invention are described using a vehicle terminal as the execution entity.

[0022] The vehicle terminal obtains a first actual state parameter and a target negative acceleration of the vehicle. The first actual state parameter includes at least a first driving speed. The actual state parameter may also include an actual brake opening, an actual brake torque, and an actual negative acceleration. In this embodiment, the actual state parameters may be obtained by various sensors installed on the unmanned vehicle, including but not limited to a vehicle wheel speed sensor, a brake pedal opening sensor, a vehicle longitudinal acceleration sensor, and a vehicle torque sensor. The brake opening indicates the braking capacity of the brake actuator. The brake opening may be sent as a command value to a hydraulic brake actuator for hydraulic braking. A larger value indicates a stronger braking force. The actual brake opening may be obtained by detecting the change in cylinder pressure before and after braking using a brake cylinder pressure sensor, by detecting the change in brake pedal depth or brake pedal travel before and after braking, or by other methods, without limitation. The brake torque may be sent as a command value to an electric brake actuator for electric braking. A larger actual brake torque applied by the electric brake actuator indicates a stronger braking force, and more energy is recovered through the energy recovery strategy. The recovered energy can be used as energy supplement during driving of the new energy vehicle, thereby achieving other beneficial effects.

[0023] Negative acceleration in the present invention refers to vehicle acceleration in the opposite direction of travel, i.e., the vehicle is in a braking deceleration state. The increase in negative acceleration described in this and subsequent embodiments refers to an increase in the absolute value of the negative acceleration, without changing its direction. A greater negative acceleration means a greater braking force. The target negative acceleration is the target deceleration requirement calculated by the vehicle's braking system using artificial intelligence based on the vehicle's actual state parameters and driving environment. The greater the absolute value, the faster the vehicle's speed decreases per unit time. Dynamic adjustment of the target negative acceleration based on the actual driving conditions or the driver's driving habits enables unmanned driving to accurately follow the planned trajectory while ensuring comfort and safety during driving.

[0024] 102. Calculate the total braking demand based on the target negative acceleration and a preset brake table. The total braking demand includes the target brake opening.

[0025] The vehicle terminal calculates the total braking demand, which includes the target brake opening, based on the target negative acceleration and a pre-set brake table. The brake table in this embodiment is calibrated using the actual state parameters of the unmanned vehicle under different operating conditions. The brake table includes a first brake table, a second brake table, and a third brake table. The first brake table indicates the correspondence between brake opening and negative acceleration, the second brake table indicates the correspondence between braking torque and negative acceleration, and the third brake table indicates the correspondence between braking torque and brake opening.

[0026] In one feasible implementation, a first brake table is queried according to the target negative acceleration to obtain a target brake opening, and the target brake opening is sent as a command value to the hydraulic actuator, which is the hydraulic brake demand opening; or, a second brake table is queried according to the target negative acceleration to obtain a target brake torque, and the target brake torque is sent as a command value to the motor control unit (MCU), which is the electric brake demand torque.

[0027] The preset brake table in this embodiment is a basic brake table calibrated when the unmanned vehicle is first put into use. During the daily driving of the unmanned vehicle, the vehicle terminal can continuously collect braking data and upload it to the cloud for correction and updating of the brake table. As the unmanned vehicle is run-in for a long time, the cloud will regularly update the brake table, so that the drive-by-wire controller (DBW) software of the vehicle terminal can continuously obtain the latest brake table for braking control, so as to eliminate the difference in braking system performance between the initial state and the subsequent actual use state of the unmanned vehicle, improve the accuracy of braking control, and meet the requirements of braking safety, driving comfort, and braking stability.

[0028] 103. Perform braking distribution according to the first driving speed and the total braking demand to obtain a first target braking mode and a first target braking command value. The first target braking mode is used to instruct execution of electric braking and / or hydraulic braking.

[0029] The vehicle terminal performs braking distribution according to the first driving speed and the total braking demand to obtain a first target braking mode and a first target braking command value. The first target braking mode is used to instruct the execution of electric braking and / or hydraulic braking.

[0030] In a feasible implementation manner, the vehicle terminal determines whether the first driving speed is greater than or equal to the first preset speed. If not, the first target braking mode is determined to be hydraulic braking, and the target brake opening is determined as the first braking command value, and the first braking command value is the first target braking command value for hydraulic braking. If so, the hydraulic brake enable is turned off and the electric brake enable is turned on; the electric brake demand torque is calculated according to the target negative acceleration and the preset second brake table; the electric brake demand torque is sent to the motor actuator Motor to perform electric braking, and the first actual negative acceleration and the first actual braking torque are obtained; the electric brake demand torque and the first actual negative acceleration are determined. Whether the actual negative acceleration meets the preset conditions, the preset conditions are used to indicate whether the maximum braking output of the electric brake (that is, the maximum braking torque that the motor actuator can provide) is less than the total braking demand. If not, the first target braking mode is determined to be electric braking, and the electric braking demand torque is determined as the second braking command value, and the second braking command value is the first target braking command value for electric braking. If so, the first target braking mode is determined to be electric braking and hydraulic braking, and the braking command value for supplementary hydraulic braking is calculated based on the first actual braking torque and the total braking demand, and the maximum electric braking torque is determined as the braking command value for electric braking, and hydraulic braking and electric braking are performed at the same time.

[0031] In this embodiment, the first preset speed is the minimum driving speed that needs to be reached when the braking torque generated by the energy recovered by the electric brake can enable the vehicle to brake completely by electric braking. The value can be calibrated through experiments based on different vehicles. The first preset speed can be set to 10 km / h or other values. When the first driving speed is lower than the first preset speed, the motor speed is low, and the energy recovery is insufficient to generate sufficient braking torque, forcing the vehicle to brake completely by electric braking. At this time, the target brake opening corresponding to the total braking demand is used as the first target braking command value and sent to the hydraulic actuator for pure hydraulic braking.

[0032] In this embodiment, the preset conditions include a first preset condition and a second preset condition. The first preset condition is that the electric braking demand torque is greater than the maximum electric braking torque, that is, the maximum braking force that can be provided by the electric brake alone does not meet the total braking demand. The second preset condition is that the absolute value of the first actual negative acceleration is less than the absolute value of the maximum negative acceleration of the electric brake, that is, the actual negative acceleration that can be provided by the electric brake alone does not reach the target negative acceleration. When the first preset condition and / or the second preset condition are met, it indicates that the braking force output by the electric brake does not meet the total braking demand and supplementary hydraulic braking is required.

[0033] In a feasible embodiment, the braking command value for supplementary hydraulic braking is calculated based on the first actual braking torque and the total braking demand, including: generating a first actual braking opening based on the first actual braking torque and a preset third brake table; performing a difference operation between the target braking opening of the total braking demand and the first actual braking opening to obtain a first braking opening; and determining the first braking opening as the braking command value for supplementary hydraulic braking.

[0034] 104. Perform braking control according to the first target braking mode and the first target braking command value.

[0035] The vehicle terminal sends the first target braking command value to the corresponding brake actuator for braking control according to the first target braking mode, adjusts the braking demand in real time according to the actual negative acceleration of the vehicle, and repeats the above braking control method until the vehicle stops or reaches the target driving speed, or stops braking control according to the actual driving conditions.

[0036] In actual situations, if the first target braking mode determined according to the first actual state parameter is to perform electric braking, the actual driving speed of the vehicle decreases with braking. When the actual driving speed is less than the first preset speed, the motor speed is low, and the energy recovered by the electric braking is small, and it is necessary to switch from electric braking to hydraulic braking. Or when the first target braking mode is to perform electric braking and hydraulic braking, as the actual driving speed decreases, it will also involve switching from electric braking and hydraulic braking to electric braking, and further from electric braking to hydraulic braking. In order to ensure the smoothness of the above braking mode switching process, in a feasible implementation method, the second actual state parameter is obtained. When the second actual state parameter meets the preset switching condition, the unit change of the first target braking command value and the second target braking command value is determined according to the preset dynamic coordinated braking algorithm; and the first target braking mode is switched to the second target braking mode according to the unit change.

[0037] In this embodiment, the switching condition may be that the second driving speed is less than or equal to the second preset speed, and the second preset speed is greater than or equal to the first preset speed, which can be selected based on actual circumstances. The first target braking command value may be a first braking command value, a second braking command value, a third braking command value, or a fourth braking command value. The first braking command value is the target brake opening sent to the hydraulic actuator when hydraulic braking is performed in the first target braking mode; the second braking command value is the electric braking demand torque sent to the motor actuator when electric braking is performed in the first target braking mode; the third braking command value is the brake opening sent to the hydraulic actuator when both electric and hydraulic braking are performed in the first target braking mode; and the fourth braking command value is the maximum braking torque sent to the motor actuator when both electric and hydraulic braking are performed in the first target braking mode.

[0038] When the switching conditions are met, the first target braking command value corresponding to the first target braking mode is gradually reduced according to a preset first unit change amount, and the second target braking command value corresponding to the second target braking mode is gradually increased according to a preset second unit change amount, so as to maintain the actual negative acceleration unchanged or change within a smaller range during the braking mode switching process until the braking mode switching is completed, so as to ensure smoothness during the braking mode switching process.

[0039] For example, the first target braking mode is to perform electric braking, and the second target braking mode is to perform hydraulic braking. When the second driving speed is less than or equal to the second preset speed, the braking torque performed by the electric brake is N1. At this time, the total negative acceleration is all provided by the electric brake, and the hydraulic brake opening corresponding to the hydraulic brake is zero. During the dynamic coordinated braking process, the total negative acceleration V t Provided by electric brake and hydraulic brake at the same time, dynamic coordinated braking algorithm maintains V t The switching of the first target braking mode to the second target braking mode is performed unchanged or changes within a preset range until the target braking mode is switched. The process of switching from the first target braking mode to the second target braking mode can be expressed as:

[0040]

[0041] Wherein, N is the electric braking torque;

[0042] △N is the unit change of the braking torque performed by the electric brake;

[0043] △M is the unit change of brake opening executed by hydraulic brake;

[0044] M is the brake opening degree executed by hydraulic brake;

[0045] t is time, and t is a positive integer greater than 1;

[0046] V is the total negative acceleration provided by the brake actuator, V = V N +V M ;

[0047] V1 is the total negative acceleration when the switching condition is met;

[0048] N1 is the electric braking torque when the switching conditions are met;

[0049] V N The negative acceleration provided by the electric brake can be obtained by querying the second brake table at the corresponding moment N, or by obtaining actual data from sensors installed on the vehicle;

[0050] V MThe negative acceleration provided by the hydraulic brake can be obtained by querying the first brake table at the corresponding moment M, or by obtaining actual data from sensors installed on the vehicle;

[0051] That is, when switching the braking mode, the brake actuator will not directly reset the first target braking command value to zero and directly switch to the second target braking command value, but will control the first target braking command value of the original brake actuator (i.e., the motor actuator) to gradually decrease according to the first unit change amount according to the coordinated control command value, and control the rear brake actuator (i.e., the hydraulic actuator) to gradually increase according to the second unit change amount until the total braking demand is completely allocated to the hydraulic brake actuator.

[0052] For another example, the first target braking mode is to execute electric braking and hydraulic braking, and the second target braking mode is to execute electric braking. When the second actual state parameter meets the preset switching condition, the first target braking command value includes a third braking command value for hydraulic braking and a fourth braking command value for electric braking. When the first target braking mode is to execute electric braking and hydraulic braking, in order to maximize the energy recovery rate, the fourth braking command value is generally the maximum braking torque. Therefore, the fourth braking command value cannot be increased, and the third braking command value only needs to be controlled to gradually decrease according to the first unit change amount to maintain V t It changes smoothly within the preset range, and its switching process can be expressed as:

[0053]

[0054] Among them, N max Maximum braking torque performed for electric braking.

[0055] In this embodiment, electric braking and hydraulic braking can be automatically allocated, and electric braking is used as the main braking mode for unmanned driving, which reduces the frequency of use of hydraulic brake actuators, reduces the risk of frequent brake failure of hydraulic brake actuators, extends the service life of hydraulic brake actuators, and ensures the stability of the vehicle during braking; using electric braking as the main method can improve the energy recovery rate, thereby extending the cruising range of new energy vehicles; electric braking uses torque to control acceleration, which is smoother than hydraulic braking's cylinder pressure control acceleration. The braking capacity of hydraulic braking is stronger than electric braking. Combining the advantages of the two, hydraulic braking is used as a backup and compensatory redundant braking, which reduces the cost of wire control, meets the braking needs in various situations, and takes into account the safety, economy and driving comfort of the unmanned vehicle during driving. By obtaining and regularly correcting the brake table through the cloud, the brake mutation and delay problems that occur during the switching process between electric braking mode and hydraulic braking mode are solved, ensuring the smoothness of braking mode switching and improving the accuracy of braking control.

[0056] See also Figure 2Another embodiment of the braking control method for an unmanned vehicle according to the present invention includes:

[0057] 201. Obtain a first actual state parameter and a target negative acceleration of a vehicle, where the first actual state parameter includes at least a first driving speed.

[0058] Step 201 is similar to the above step 101 and will not be described again here.

[0059] 202. Calculate the total braking demand based on the target negative acceleration and a preset brake table. The total braking demand includes the target brake opening.

[0060] The vehicle terminal determines the target brake opening according to the target negative acceleration and a preset first brake table, where the first brake table is used to indicate the correspondence between the brake opening and the negative acceleration; and determines the target brake opening as the total braking demand.

[0061] 203. Perform braking distribution according to the first driving speed and the total braking demand to obtain a first target braking mode and a first target braking command value, where the first target braking mode is used to instruct execution of electric braking and / or hydraulic braking.

[0062] In a feasible implementation manner, when the first driving speed is less than the first preset speed, the first target braking mode is determined to be hydraulic braking, and the target brake opening is determined as the first braking command value, and the first braking command value is the first target braking command value for hydraulic braking; when the first driving speed is greater than or equal to the first preset speed, the electric braking demand torque is generated according to the target negative acceleration and the preset second brake table; the electric braking demand torque is sent to the motor actuator to perform electric braking, and the first actual negative acceleration and the first actual braking torque are obtained; when the electric braking demand torque is less than or equal to the maximum electric braking torque, and / or the absolute value of the first actual negative acceleration is greater than or equal to the maximum negative acceleration of the electric brake, When the absolute value of the speed is greater than the maximum electric braking torque, the first target braking mode is determined to be electric braking, and the electric braking required torque is determined as the second braking command value, and the second braking command value is the first target braking command value for electric braking; when the electric braking required torque is greater than the maximum electric braking torque, or the absolute value of the first actual negative acceleration is less than the absolute value of the maximum negative acceleration of electric braking, the first target braking mode is determined to be electric braking and hydraulic braking, and the first target braking command value is generated according to the first actual braking torque, the preset third brake table, the target brake opening, the preset first brake table and the maximum electric braking torque. The first target braking command value includes the third braking command value for hydraulic braking and the fourth braking command value for electric braking.

[0063] In a feasible implementation, before generating the electric braking demand torque according to the target negative acceleration and the preset second brake table, it also includes: turning off the hydraulic braking enable and turning on the electric braking enable. At this time, electric braking is used as the main braking. In actual conditions, taking an unmanned bus as an example, the maximum electric braking torque of the motor can reach 212N, and the maximum replicated acceleration generated can reach -2.2m / s^2, which can cover most of the negative acceleration demand scenarios on urban bus roads. Hydraulic braking is only enabled as compensation and emergency braking to compensate for the insufficient braking force of electric braking.

[0064] In a feasible embodiment, the vehicle terminal generates a first actual brake opening based on the first actual brake torque and a preset third brake table, and the third brake table is used to indicate the correspondence between the brake torque and the brake opening; generates a first brake opening based on the target brake opening and the first actual brake opening; determines the first brake opening as the third brake command value executed by hydraulic braking; and determines the maximum electric brake torque as the fourth brake command value executed by electric braking.

[0065] In order to avoid sudden changes in negative acceleration when hydraulic braking is used as a supplementary brake, which may cause brake judder and unevenness and affect the driving experience, in a feasible embodiment, the vehicle terminal generates a first actual brake opening based on the first actual brake torque and a preset third brake table; generates a first brake opening based on the target brake opening and the first actual brake opening; determines a first negative acceleration of the hydraulic brake based on the first brake opening and the preset first brake table; performs a difference operation on the first negative acceleration and the first actual negative acceleration to obtain a negative acceleration difference result; determines whether the negative acceleration difference result is greater than a preset value; if not, determines the first brake opening as the third brake command value executed by the hydraulic brake; if so, corrects the first brake opening to obtain a second brake opening, and determines the second brake opening as the third brake command value executed by the hydraulic brake.

[0066] In this embodiment, the value of the preset value is the key to the smoothness of supplementary braking. An excessively large preset value will result in excessive supplementary hydraulic braking, and the joint braking of electric braking and hydraulic braking will cause the actual negative acceleration to increase too quickly, resulting in jitter. An excessively small preset value will result in too small a change in the negative acceleration, and it is necessary to coordinate and control the distribution ratio of electric braking and hydraulic braking multiple times to meet the braking requirements, resulting in a slow braking speed. Setting an appropriate preset value can take into account the smoothness of supplementary braking and the needs of rapid braking. The size of the preset value can be experimentally calibrated according to different vehicles. The preset value can be 0.3m / s^2 or other values.

[0067] In one feasible embodiment, when the negative acceleration difference is greater than a preset value, the first brake opening is corrected to obtain a second brake opening, including: determining a third unit change based on the total braking demand, the first actual braking torque, the first brake opening, and the dynamic coordinated braking algorithm; determining the second brake opening based on the third unit change of the third brake command value, and increasing the second brake opening according to the unit change until the second brake opening is equal to the first brake opening. In this case, in order to implement the electric braking that cannot meet the total braking demand, hydraulic braking is required to supplement the braking force. This is generally the case in the high-speed or emergency braking state of unmanned vehicles. The third unit change is maximized while taking into account smoothness to achieve the purpose of rapid supplementary braking. The mode switching process can be expressed as:

[0068]

[0069] Among them, V 目 is the target negative acceleration, used to indicate the total braking demand;

[0070] V Nmax The maximum negative acceleration provided for electric braking.

[0071] 204. Perform braking control according to the first target braking mode and the first target braking command value.

[0072] The vehicle terminal inputs the first target braking command value into the corresponding brake actuator according to the first target braking mode to perform hydraulic braking and / or electric braking. The brake actuator can be a hydraulic actuator and / or an electric actuator, the hydraulic actuator performs hydraulic braking, and the electric actuator performs electric braking. According to the above method, the unmanned vehicle uses electric braking energy recovery as the main braking method at high speeds, while hydraulic braking is used as a backup redundant braking method to compensate for insufficient braking force. At low speeds, due to the low energy recovery of the motor, hydraulic braking is mainly used. In this way, the main working range of the hydraulic brake is concentrated at low speeds, reducing its risk of failure. Electric braking and hydraulic braking are redundant and complement each other, thereby enhancing the robustness of the unmanned vehicle's braking.

[0073] 205. Obtain a second actual state parameter.

[0074] The vehicle terminal obtains the second actual state parameter, which may include an actual brake load ratio, a second driving speed, a second actual negative acceleration, a second actual brake opening, and a second actual brake torque.

[0075] In this embodiment, the actual braking load ratio refers to the ratio between the braking force acting on the wheel of the vehicle under actual working conditions and the maximum braking force acting on the wheel of the vehicle under full load conditions, which is used to indicate the braking degree of the vehicle braking system. The actual braking load ratio can be obtained by: calculating the ratio of the actual braking torque performed by electric braking to the maximum braking torque of electric braking to obtain the first braking load ratio of electric braking; calculating the ratio of the actual braking opening performed by hydraulic braking to the maximum braking opening of hydraulic braking to obtain the second load ratio of hydraulic braking; determining the actual braking load based on the first load ratio and the second load ratio, or it can be obtained by other methods.

[0076] 206. Update the brake table according to the first target braking mode, the second actual state parameter, and the preset load ratio.

[0077] The vehicle terminal updates the brake table based on the first target braking mode, the second actual state parameter, and the preset load ratio, and saves it to the cloud for the next braking control. The preset load ratio can be set to 60% of the actual braking load ratio, meaning the actual braking force on the wheel accounts for 60% of the maximum braking force, or other values.

[0078] The vehicle terminal determines whether to update the brake table based on whether the energy recovery function is turned on and whether the hydraulic brake enable is turned off in the configuration. When the energy recovery function is turned off, only hydraulic braking is used, and the load ratio reaches 60%, the vehicle terminal calibrates the brake opening and the brake negative acceleration to obtain a first calibration value, and updates the first calibration value to the first brake table; when the energy recovery function is turned on, the hydraulic brake enable is turned off, only electric braking is used, and the load ratio reaches 60%, the vehicle terminal calibrates the brake torque and the brake negative acceleration to obtain a second calibration value, and calibrates the brake torque and brake opening to obtain a third calibration value, updates the second calibration value to the second brake table, and updates the third calibration value to the third brake table.

[0079] In a feasible embodiment, when the first target braking mode is to perform hydraulic braking, the actual braking load ratio, the second actual negative acceleration and the second actual braking opening are obtained; when the actual braking load ratio reaches a preset load ratio, the correspondence between the second actual negative acceleration and the second actual braking opening is determined; and the correspondence between the second actual negative acceleration and the second actual braking opening is updated to the first brake table.

[0080] In a feasible embodiment, when the first target braking mode is to perform electric braking, the actual braking load ratio, the second actual negative acceleration, the second actual braking torque and the second actual brake opening are obtained; when the actual braking load ratio reaches the preset load ratio, the correspondence between the second actual braking torque and the second actual negative acceleration, as well as the correspondence between the second actual braking torque and the second actual brake opening are determined; the correspondence between the second actual braking torque and the second actual negative acceleration is updated to the second brake table; and the second actual braking torque and the second actual brake opening are updated to the third brake table.

[0081] 207. Adjust the total braking demand according to the second actual state parameter.

[0082] The vehicle terminal adjusts the total braking demand in real time according to the second driving speed and the second actual negative acceleration in the second actual state parameters, and repeats the above braking steps according to the new total braking demand until the vehicle stops or reaches the target driving speed, or stops braking control according to the actual driving conditions.

[0083] 208. Switch the first target braking mode to the second target braking mode according to the second actual state parameter and the dynamic coordinated braking algorithm.

[0084] The vehicle terminal switches the first target braking mode to the second target braking mode according to the second actual state parameter and the dynamic coordinated braking algorithm.

[0085] In a feasible embodiment, when the second actual state parameter meets the preset switching condition, the first unit change of the first target braking command value is determined according to the first target braking mode, the first target braking command value and the dynamic coordinated braking algorithm; the second target braking command value and the second unit change are determined according to the second actual state parameter, the braking table and the dynamic coordinated braking algorithm; and the first target braking mode is switched to the second target braking mode according to the first target braking command value, the first unit change, the second target braking command value and the second unit change.

[0086] In an embodiment of the present invention, electric braking and hydraulic braking can be automatically allocated, and electric braking is used as the primary braking mode for unmanned driving. This reduces the frequency of use of the hydraulic brake actuator, reduces the risk of frequent brake failure of the hydraulic brake actuator, extends the service life of the hydraulic brake actuator, and ensures the stability of the vehicle during braking. The use of electric braking as the primary braking method can improve the energy recovery rate, thereby extending the cruising range of new energy vehicles. Electric braking uses torque to control acceleration, which is smoother than hydraulic braking's cylinder pressure control acceleration. Hydraulic braking has stronger braking capacity than electric braking. Combining the advantages of both, hydraulic braking is used as a backup and compensatory redundant brake, reducing the cost of wire control, meeting braking needs in various situations, and taking into account the safety, economy, and driving comfort of the unmanned vehicle during driving. By obtaining and regularly updating the brake table through the cloud, the problems of brake mutation and delay that occur during the switching process between electric braking mode and hydraulic braking mode are solved, ensuring the smoothness of braking mode switching. The total braking demand is adjusted in real time according to actual state parameters, improving the accuracy of braking control.

[0087] The above describes the braking control method of the unmanned vehicle in the embodiment of the present invention. The following describes the braking control device of the unmanned vehicle in the embodiment of the present invention. Figure 3 In one embodiment of the present invention, a braking control device for an unmanned vehicle includes:

[0088] A first acquisition module 301 is configured to acquire a first actual state parameter and a target negative acceleration of the vehicle, wherein the first actual state parameter includes at least a first driving speed;

[0089] A calculation module 302 is configured to calculate a total braking demand based on a target negative acceleration and a preset braking table, where the total braking demand includes a target brake opening;

[0090] an allocating module 303 configured to perform braking allocation according to the first driving speed and the total braking demand, and obtain a first target braking mode and a first target braking command value, wherein the first target braking mode is used to instruct execution of electric braking and / or hydraulic braking;

[0091] The braking module 304 is configured to perform braking control according to a first target braking mode and a first target braking command value.

[0092] In an embodiment of the present invention, electric braking and hydraulic braking can be automatically allocated, and electric braking is used as the primary braking mode for unmanned driving. This reduces the frequency of use of the hydraulic brake actuator, reduces the risk of frequent brake failure of the hydraulic brake actuator, extends the service life of the hydraulic brake actuator, and ensures the stability of the vehicle during braking. The use of electric braking as the primary braking mode can improve the energy recovery rate, thereby extending the cruising range of new energy vehicles. Electric braking uses torque to control negative acceleration, which has a faster response speed and smoother control than hydraulic braking. It can solve the problem of braking delay. The braking capacity of hydraulic braking is stronger than that of electric braking. Combining the advantages of both, hydraulic braking is used as a backup and compensatory redundant braking, reducing the cost of wire control, meeting braking needs in various situations, and taking into account the safety, economy, and driving comfort of the unmanned vehicle during driving. By obtaining and regularly updating the brake table through the cloud, the problems of brake mutation and delay that occur during the switching process between electric braking mode and hydraulic braking mode are solved, ensuring the smoothness of braking mode switching and improving the accuracy of braking control.

[0093] See also Figure 4 Another embodiment of the brake control device for an unmanned vehicle according to the present invention includes:

[0094] A first acquisition module 301 is configured to acquire a first actual state parameter and a target negative acceleration of the vehicle, wherein the first actual state parameter includes at least a first driving speed;

[0095] A calculation module 302 is configured to calculate a total braking demand based on a target negative acceleration and a preset braking table, where the total braking demand includes a target brake opening;

[0096] an allocating module 303 configured to perform braking allocation according to the first driving speed and the total braking demand, and obtain a first target braking mode and a first target braking command value, wherein the first target braking mode is used to instruct execution of electric braking and / or hydraulic braking;

[0097] The braking module 304 is configured to perform braking control according to a first target braking mode and a first target braking command value.

[0098] Optionally, the calculation module 302 is specifically used to: determine the target brake opening according to the target negative acceleration and a preset first brake table, the first brake table is used to indicate the correspondence between the brake opening and the negative acceleration; and determine the target brake opening as the total braking demand.

[0099] Optionally, the allocation module 303 includes:

[0100] The first processing unit 3031 is configured to determine, when the first driving speed is less than a first preset speed, that the first target braking mode is hydraulic braking, and to determine the target brake opening as a first braking command value, the first braking command value being a first target braking command value for hydraulic braking;

[0101] The second processing unit 3032 is configured to generate an electric braking demand torque according to the target negative acceleration and a preset second brake table when the first driving speed is greater than or equal to a first preset speed;

[0102] The third processing unit 3033 is configured to send the electric braking demand torque to the motor actuator to perform electric braking, and obtain a first actual negative acceleration and a first actual braking torque;

[0103] a fourth processing unit 3034 configured to determine that the first target braking mode is to execute electric braking, and to determine the electric braking required torque as a second braking command value, the second braking command value being a first target braking command value for electric braking, when the electric braking required torque is less than or equal to the maximum electric braking torque and / or the absolute value of the first actual negative acceleration is greater than or equal to the absolute value of the maximum negative acceleration of electric braking;

[0104] The fifth processing unit 3035 is used to determine that the first target braking mode is to perform electric braking and hydraulic braking when the electric braking demand torque is greater than the maximum electric braking torque, or the absolute value of the first actual negative acceleration is less than the absolute value of the maximum negative acceleration of the electric braking, and to generate a first target braking command value according to the first actual braking torque, the preset third brake table, the target braking opening, the preset first brake table and the maximum electric braking torque. The first target braking command value includes the third braking command value executed by hydraulic braking and the fourth braking command value executed by electric braking.

[0105] Optionally, the fifth processing unit 3035 is specifically used to: generate a first actual brake opening based on the first actual brake torque and a preset third brake table, the third brake table being used to indicate the correspondence between the brake torque and the brake opening; generate a first brake opening based on the target brake opening and the first actual brake opening; determine the first brake opening as a third brake command value executed by hydraulic braking; and determine the maximum electric brake torque as a fourth brake command value executed by electric braking.

[0106] Optionally, the fifth processing unit 3035 is specifically used to: generate a first actual brake opening based on the first actual brake torque and a preset third brake table; generate a first brake opening based on the target brake opening and the first actual brake opening; determine a first negative acceleration of the hydraulic brake based on the first brake opening and the preset first brake table; perform a difference operation on the first negative acceleration and the first actual negative acceleration to obtain a negative acceleration difference result; determine whether the negative acceleration difference result is greater than a preset value; if not, determine the first brake opening as the third brake command value executed by the hydraulic brake; if so, correct the first brake opening to obtain a second brake opening, and determine the second brake opening as the third brake command value executed by the hydraulic brake.

[0107] Optionally, the fifth processing unit 3035 is specifically used to determine the unit change of the third braking command value based on the total braking demand, the first actual braking torque, the first brake opening and the preset dynamic coordinated braking algorithm; determine the second brake opening based on the unit change of the third braking command value, and the second brake opening is increased according to the unit change until the second brake opening is equal to the first brake opening.

[0108] Optionally, the brake control device of the unmanned vehicle further includes:

[0109] A second acquisition module 305 is used to acquire a second actual state parameter;

[0110] The updating module 306 is configured to update the braking table according to the first target braking mode, the second actual state parameter, and the preset load ratio.

[0111] Optionally, the brake control device of the unmanned vehicle further includes:

[0112] The adjustment module 307 is configured to adjust the total braking demand according to the second actual state parameter.

[0113] Optionally, the brake control device of the unmanned vehicle further includes:

[0114] The switching module 308 is configured to switch the first target braking mode to the second target braking mode according to the second actual state parameter and the dynamic coordinated braking algorithm.

[0115] Optionally, the switching module 308 is specifically used to determine the first unit change of the first target braking command value according to the first target braking mode, the first target braking command value and the dynamic coordinated braking algorithm when the second actual state parameter meets the preset switching condition; determine the second target braking command value and the second unit change according to the second actual state parameter, the brake table and the dynamic coordinated braking algorithm; and switch the first target braking mode to the second target braking mode according to the first target braking command value, the first unit change, the second target braking command value and the second unit change.

[0116] Optionally, the update module 306 is specifically used to, when the first target braking mode is to perform hydraulic braking, the second actual state parameter includes at least the actual braking load ratio, the second actual negative acceleration and the second actual braking opening; when the actual braking load ratio reaches the preset load ratio, determine the correspondence between the second actual negative acceleration and the second actual braking opening; and update the correspondence between the second actual negative acceleration and the second actual braking opening to the first brake table.

[0117] Optionally, the update module 306 is specifically used to, when the first target braking mode is to perform electric braking, the second actual state parameter includes at least the actual braking load ratio, the second actual negative acceleration, the second actual braking torque and the second actual braking opening; when the actual braking load ratio reaches the preset load ratio, determine the correspondence between the second actual braking torque and the second actual negative acceleration, and the correspondence between the second actual braking torque and the second actual braking opening; update the correspondence between the second actual braking torque and the second actual negative acceleration to the second brake table; and update the second actual braking torque and the second actual braking opening to the third brake table.

[0118] In an embodiment of the present invention, electric braking and hydraulic braking can be automatically allocated, and electric braking is used as the main braking mode for unmanned driving, which reduces the frequency of use of the hydraulic brake actuator, reduces the risk of frequent brake failure of the hydraulic brake actuator, extends the service life of the hydraulic brake actuator, and ensures the stability of the vehicle during braking; using electric braking as the main method can improve the energy recovery rate, thereby extending the cruising range of new energy vehicles; electric braking uses torque to control acceleration, which is smoother than hydraulic braking's cylinder pressure control acceleration. The braking capacity of hydraulic braking is stronger than electric braking. Combining the advantages of the two, hydraulic braking is used as a backup and compensatory redundant braking, which reduces the cost of wire control, meets the braking needs in various situations, and takes into account the safety, economy and driving comfort of the unmanned vehicle during driving. By obtaining and regularly correcting the brake table through the cloud, the brake mutation and delay problems that occur during the switching process between electric braking mode and hydraulic braking mode are solved, the smoothness of braking mode switching is ensured, and the accuracy of braking control is improved.

[0119] above Figure 3 and Figure 4 The braking control device of the unmanned vehicle in the embodiment of the present invention is described in detail from the perspective of modular functional entities. The braking control device of the unmanned vehicle in the embodiment of the present invention is described in detail from the perspective of hardware processing.

[0120] Figure 5 : This is a structural diagram of a brake control device for an unmanned vehicle provided by an embodiment of the present invention. The brake control device 500 for an unmanned vehicle may have relatively large differences due to different configurations or performances, and may include one or more processors (central processing units, CPU) 510 (for example, one or more processors) and a memory 520, and one or more storage media 530 (for example, one or more mass storage devices) storing application programs 533 or data 532. Among them, the memory 520 and the storage medium 530 can be temporary storage or permanent storage. The program stored in the storage medium 530 may include one or more modules (not shown in the figure), and each module may include a series of instruction operations in the brake control device 500 of the unmanned vehicle. Furthermore, the processor 510 can be configured to communicate with the storage medium 530 to execute a series of instruction operations in the storage medium 530 on the brake control device 500 of the unmanned vehicle.

[0121] The brake control device 500 for an unmanned vehicle may further include one or more power supplies 540, one or more wired or wireless network interfaces 550, one or more input / output interfaces 560, and / or one or more operating systems 531, such as Windows Server, Mac OS X, Unix, Linux, FreeBSD, etc. It will be appreciated by those skilled in the art that Figure 5 The illustrated structure of the brake control device for an unmanned vehicle does not limit the brake control device for an unmanned vehicle and may include more or fewer components than shown, or a combination of certain components, or a different arrangement of components.

[0122] The present invention also provides a braking control device for an unmanned vehicle. The computer device includes a memory and a processor. The memory stores computer-readable instructions. When the computer-readable instructions are executed by the processor, the processor executes the steps of the braking control method for the unmanned vehicle in the above-mentioned embodiments.

[0123] The present invention also provides a computer-readable storage medium, which may be a non-volatile computer-readable storage medium or a volatile computer-readable storage medium. The computer-readable storage medium stores instructions, which, when executed on a computer, cause the computer to execute the steps of the braking control method for an unmanned vehicle.

[0124] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0125] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk, etc., various media that can store program code.

[0126] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features thereof can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A braking control method for an unmanned vehicle, characterized in that: The braking control method of the unmanned vehicle includes: Acquiring a first actual state parameter and a target negative acceleration of the vehicle, wherein the first actual state parameter includes at least a first driving speed; Calculating a total braking demand based on the target negative acceleration and a preset braking table, wherein the total braking demand is a target brake opening or a target braking torque; performing braking distribution according to the first driving speed and the total braking demand to obtain a first target braking mode and a first target braking command value, wherein the first target braking mode is used to instruct execution of electric braking and / or hydraulic braking; performing braking control according to the first target braking mode and the first target braking command value; Obtaining a second actual state parameter; adjusting the total braking demand according to the second actual state parameter; switching the first target braking mode to a second target braking mode according to the second actual state parameter and a preset dynamic coordinated braking algorithm; Calculating the total braking demand based on the target negative acceleration and a preset braking table includes: determining a target brake opening according to the target negative acceleration and a preset first brake table, wherein the first brake table is used to indicate a corresponding relationship between the brake opening and the negative acceleration; or A preset second brake table is queried according to the target negative acceleration to obtain a target braking torque, wherein the second brake table is used to indicate a corresponding relationship between the braking torque and the negative acceleration.

2. The brake control method for an unmanned vehicle according to claim 1, wherein: The performing of braking distribution according to the first driving speed and the total braking demand to obtain a first target braking mode and a first target braking command value, wherein the first target braking mode is used to instruct execution of electric braking and / or hydraulic braking, includes: When the first driving speed is less than a first preset speed, the first target braking mode is determined to be hydraulic braking, and the target brake opening is determined as a first braking command value, the first braking command value being a first target braking command value for hydraulic braking; When the first driving speed is greater than or equal to a first preset speed, generating an electric braking demand torque according to the target negative acceleration and a preset second brake table; Sending the electric braking demand torque to the motor actuator to perform electric braking, and obtaining a first actual negative acceleration and a first actual braking torque; When the electric braking required torque is less than or equal to the maximum electric braking torque, and / or the absolute value of the first actual negative acceleration is greater than or equal to the absolute value of the maximum negative acceleration of electric braking, determining that the first target braking mode is to perform electric braking, and determining the electric braking required torque as a second braking command value, the second braking command value being a first target braking command value for electric braking; When the electric braking demand torque is greater than the maximum electric braking torque, or the absolute value of the first actual negative acceleration is less than the absolute value of the maximum negative acceleration of the electric braking, the first target braking mode is determined to be to perform electric braking and hydraulic braking, and a first target braking command value is generated according to the first actual braking torque, the preset third brake table, the target braking opening, the preset first brake table and the maximum electric braking torque. The first target braking command value includes a third braking command value executed by hydraulic braking and a fourth braking command value executed by electric braking.

3. The braking control method of an unmanned vehicle according to claim 2, characterized in that: The first target braking command value is generated according to the first actual braking torque, the preset third brake table, the target brake opening and the maximum electric braking torque, wherein the first target braking command value includes a third braking command value executed by hydraulic braking and a fourth braking command value executed by electric braking, including: generating a first actual brake opening according to the first actual brake torque and a preset third brake table, wherein the third brake table is used to indicate a corresponding relationship between the brake torque and the brake opening; generating a first brake opening according to the target brake opening and the first actual brake opening; determining the first brake opening as a third brake command value for hydraulic braking execution; The maximum electric braking torque is determined as a fourth braking command value for electric braking execution.

4. The brake control method for an unmanned vehicle according to claim 2, wherein: The first target braking command value is generated according to the first actual braking torque, the preset third brake table, the target brake opening and the maximum electric braking torque, wherein the first target braking command value includes a third braking command value executed by hydraulic braking and a fourth braking command value executed by electric braking, including: generating a first actual brake opening according to the first actual braking torque and a preset third brake table; generating a first brake opening according to the target brake opening and the first actual brake opening; determining a first negative acceleration of the hydraulic brake according to the first brake opening and a preset first brake table; Performing a difference operation on the first negative acceleration and the first actual negative acceleration to obtain a negative acceleration difference result; Determine whether the negative acceleration difference result is greater than a preset value; If not, determining the first brake opening as a third brake command value for hydraulic braking execution; If so, the first brake opening is corrected to obtain a second brake opening, and the second brake opening is determined as a third brake command value for hydraulic braking.

5. The brake control method for an unmanned vehicle according to claim 4, characterized in that: The correcting the first brake opening to obtain a second brake opening includes: determining a unit change of a third braking command value according to the total braking demand, the first actual braking torque, the first brake opening, and a preset dynamic coordinated braking algorithm; A second brake opening is determined according to a unit change amount of the third brake command value, and the second brake opening is increased according to the unit change amount until the second brake opening is equal to the first brake opening.

6. The braking control method of an unmanned vehicle according to claim 1, wherein: After obtaining the second actual state parameter, the method further includes: The brake table is updated according to the first target braking mode, the second actual state parameter and a preset load ratio.

7. The brake control method for an unmanned vehicle according to claim 1, wherein: The step of switching the first target braking mode to the second target braking mode according to the second actual state parameter and the dynamic coordinated braking algorithm includes: When the second actual state parameter satisfies a preset switching condition, determining a first unit change of the first target braking command value according to the first target braking mode, the first target braking command value, and the dynamic coordinated braking algorithm; determining a second target braking command value and a second unit variation according to the second actual state parameter, the braking table, and the dynamic coordinated braking algorithm; The first target braking mode is switched to a second target braking mode according to the first target braking command value, the first unit change amount, the second target braking command value, and the second unit change amount.

8. The brake control method for an unmanned vehicle according to claim 6, wherein: The updating of the brake table according to the first target braking mode, the second actual state parameter and the preset load ratio includes: When the first target braking mode is to perform hydraulic braking, the second actual state parameter includes at least an actual brake load ratio, a second actual negative acceleration and a second actual brake opening; When the actual brake load ratio reaches a preset load ratio value, determining a corresponding relationship between the second actual negative acceleration and the second actual brake opening; The correspondence between the second actual negative acceleration and the second actual brake opening is updated to the first brake table.

9. The brake control method for an unmanned vehicle according to claim 6, wherein: The updating of the brake table according to the first target braking mode, the second actual state parameter and the preset load ratio includes: When the first target braking mode is to perform electric braking, the second actual state parameter includes at least an actual brake load ratio, a second actual negative acceleration, a second actual braking torque, and a second actual brake opening; When the actual braking load ratio reaches a preset load ratio value, determining a corresponding relationship between the second actual braking torque and the second actual negative acceleration, and a corresponding relationship between the second actual braking torque and the second actual brake opening; updating the correspondence between the second actual braking torque and the second actual negative acceleration into a second brake table; The second actual braking torque and the second actual brake opening are updated in a third brake table.

10. A braking control device for an unmanned vehicle, characterized in that: The brake control device of the unmanned vehicle includes: A first acquisition module is configured to acquire a first actual state parameter and a target negative acceleration of the vehicle, wherein the first actual state parameter includes at least a first driving speed; a calculation module, configured to calculate a total braking demand based on the target negative acceleration and a preset brake table, wherein the total braking demand is a target brake opening or a target brake torque; an allocating module, configured to perform braking allocation according to the first driving speed and the total braking demand, and obtain a first target braking mode and a first target braking command value, wherein the first target braking mode is used to instruct execution of electric braking and / or hydraulic braking; a braking module, configured to perform braking control according to the first target braking mode and the first target braking command value; A second acquisition module, configured to acquire a second actual state parameter; an adjustment module, configured to adjust the total braking demand according to a second actual state parameter; a switching module, configured to switch the first target braking mode to a second target braking mode according to a second actual state parameter and a dynamic coordinated braking algorithm; The calculation module is specifically used to: determine the target brake opening according to the target negative acceleration and a preset first brake table, where the first brake table is used to indicate the corresponding relationship between the brake opening and the negative acceleration; or A preset second brake table is queried according to the target negative acceleration to obtain a target braking torque, wherein the second brake table is used to indicate a corresponding relationship between the braking torque and the negative acceleration.

11. A brake control device for an unmanned vehicle, characterized in that: The brake control device of the unmanned vehicle includes: a memory and at least one processor, wherein the memory stores instructions; The at least one processor calls the instructions in the memory to enable the brake control device of the unmanned vehicle to execute the brake control method of the unmanned vehicle according to any one of claims 1 to 9.

12. A computer-readable storage medium having instructions stored thereon, characterized in that: When the instruction is read and executed, the braking control method for an unmanned vehicle as claimed in any one of claims 1 to 9 is executed.

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