Pilotless automobile, braking control method and device thereof and controller

Abstract

The invention discloses a pilotless automobile and a brake control method, device and controller thereof, and relates to the technical field of pilotless control, the method comprises the following steps: in the driving process of the pilotless automobile, detecting a brake signal output by PI closed-loop control according to a preset period, and obtaining a corresponding logic brake deceleration after the brake signal is detected; the logic braking deceleration is compared with a predetermined unauthorized braking deceleration, and the larger braking deceleration serves as an output deceleration to be issued to a hydraulic braking valve; after it is detected that the hydraulic brake valve is opened, the braking deceleration is adjusted through PI closed-loop control, the braking force output by the hydraulic brake valve is subsequently adjusted, braking failure caused by too small logic braking deceleration is effectively avoided, the braking success rate is greatly increased, and various accidents caused by braking failure are reduced.

Description

Technical Field

[0001] The present application relates to the field of unmanned driving control technology, and in particular, to an unmanned driving vehicle and a braking control method, device and controller thereof. Background Art

[0002] The intervention and exit of the hydraulic brake of the unmanned mining vehicle is controlled by the opening and closing of the hydraulic valve. The opening and closing of the hydraulic valve depends on the deceleration request issued. When the deceleration request is small, it is not enough to open the hydraulic valve. In addition, the absolute value of the deceleration required to close the hydraulic valve must be less than the absolute value of the deceleration to open the hydraulic valve. This deceleration area where the small deceleration cannot open the hydraulic brake valve is referred to as the hydraulic brake deceleration dead zone. The hydraulic brake intervention is relatively slow, and the time is long, which will cause speed overshoot, causing great safety hazards during vehicle driving. Summary of the invention

[0003] In order to overcome the deficiencies of the prior art, the present application provides an unmanned vehicle and a braking control method, device and controller thereof.

[0004] The technical solution adopted by this application to solve its technical problem is:

[0005] In a first aspect, a method for controlling braking of an unmanned vehicle is provided, comprising:

[0006] During the driving process of the driverless car, the braking signal output by the PI closed-loop control is detected according to a preset period, and after the braking signal is detected, the corresponding logical braking deceleration is obtained;

[0007] Comparing the logical braking deceleration with a predetermined overriding braking deceleration, and sending the larger braking deceleration as the output deceleration to the hydraulic brake valve;

[0008] After detecting that the hydraulic brake valve is open, the PI closed-loop control adjusts the magnitude of the braking deceleration, and subsequently adjusts the magnitude of the braking force output by the hydraulic brake valve.

[0009] Furthermore, it also includes: if the opening of the hydraulic brake valve is not detected, adjusting the override braking deceleration, and comparing it with the logical braking deceleration again until the hydraulic brake valve is opened.

[0010] Furthermore, before obtaining the corresponding logical braking deceleration, the method further includes: determining whether the hydraulic brake is on; and if the hydraulic brake is not on, obtaining the corresponding logical braking deceleration.

[0011] Further, determining whether the hydraulic brake is on includes: obtaining the axle brake pressure of the driverless vehicle; comparing the axle brake pressure with a preset pressure value, and if the axle brake pressure is less than the preset pressure value, determining that the hydraulic brake is not on.

[0012] Furthermore, before comparing the logical braking deceleration with a predetermined override braking deceleration, the method also includes: determining whether the logical braking deceleration is less than a preset speed value; if the logical braking deceleration is less than the preset speed value, comparing the logical braking deceleration with a predetermined override braking deceleration.

[0013] Furthermore, before comparing the logical braking deceleration with a predetermined overriding braking deceleration, the method further comprises: calculating the overriding braking deceleration according to a dynamic compensation value and a preset calibration value.

[0014] Furthermore, before calculating the override braking deceleration according to the dynamic compensation value and the preset calibration value, the method also includes: calculating the dynamic compensation value according to the braking delay time and the preset basic deceleration, wherein the braking delay time is a period of time from the triggering of the hydraulic braking signal to the current moment.

[0015] Further, the dynamic compensation value is calculated according to the braking delay time and the preset basic deceleration: The dynamic compensation value is calculated according to the following formula: 增益 =Δa*Δt, where a 增益 is the dynamic compensation value, Δa is the preset basic deceleration, and Δt is the braking delay time.

[0016] Further, the overriding braking deceleration is calculated according to the dynamic compensation value and the preset calibration value: The dynamic compensation value is calculated according to the following formula: a1=a basic +a 增益 , where a 1 is the overriding braking deceleration, a basic is the preset calibration value, a 增益 is the dynamic compensation value.

[0017] Furthermore, a basic The value is 0.3m / s 2 , and / or, Δa is 0.1m / s 2 .

[0018] In a second aspect, a brake control device for an unmanned vehicle is provided, comprising:

[0019] The braking signal monitoring module is used to detect the braking signal output by the PI closed-loop control according to a preset period during the driving process of the unmanned vehicle, and obtain the corresponding logical braking deceleration after detecting the braking signal;

[0020] An output speed determination module, used for comparing the logical braking deceleration with a predetermined overriding braking deceleration, and sending the larger braking deceleration as the output deceleration to the hydraulic brake valve;

[0021] The brake control module is used to adjust the magnitude of the brake deceleration by PI closed-loop control after detecting that the hydraulic brake valve is opened, and subsequently adjust the magnitude of the braking force output by the hydraulic brake valve.

[0022] In a third aspect, a brake controller for an unmanned vehicle is provided, comprising:

[0023] at least one processor and at least one memory;

[0024] The memory stores executable instructions of the processor;

[0025] The processor is configured to execute the above-mentioned unmanned vehicle braking control method.

[0026] The technical solution of the present application provides a braking control method, device and controller for an unmanned vehicle disclosed in the present embodiment. During the braking control process, an overriding braking deceleration is introduced, and the larger of the logical braking deceleration and the overriding braking deceleration is used for braking control, thereby effectively avoiding braking failure caused by too small logical braking deceleration, greatly improving the braking success rate, and reducing various accidents caused by braking failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 It is a flowchart of a braking control method for an unmanned vehicle provided in an embodiment of the present application;

[0029] Figure 2 It is a flow chart of another unmanned vehicle braking control method provided in an embodiment of the present application;

[0030] Figure 3 is a functional structure diagram of a brake control device for an unmanned vehicle provided in an embodiment of the present application;

[0031] Figure 4 is a functional structure diagram of another unmanned vehicle braking control device provided in an embodiment of the present application;

[0032] Figure 5 It is a functional structure diagram of a brake controller for an unmanned vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present application is described in detail below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other implementation methods obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0034] An unmanned vehicle is an intelligent vehicle, also known as a wheeled mobile robot, which relies on an intelligent driver's instrument inside the vehicle to achieve unmanned driving. At present, unmanned vehicles have been widely used in many scenarios, such as logistics distribution, public transportation, and urban travel. The unmanned vehicle involved in the embodiments of the present application is mainly used for mine transportation. The mine area has diverse terrain and landforms, including mountains, hills, hillocks, and plains, which place higher requirements on unmanned vehicles. When an unmanned vehicle travels in such terrain, higher requirements are placed on braking control.

[0035] PI closed-loop control, also known as closed-loop PID control, is an automatic control algorithm consisting of three parts: proportional (P), integral (I) and differential (D). Specifically, proportional (P): adjusts the output proportionally according to the size of the error to reduce the error; integral (I): integrates the error to eliminate the static error of the system; differential (D): adjusts the error in advance according to the speed of error change to improve the dynamic performance of the system. The basic principle of PID control is to measure the error between the actual output and the expected output of the system, and then perform proportional, integral and differential operations on the error signal respectively, and finally linearly combine the results of these three parts to form a control quantity, which is used to control the output of the system.

[0036] Since the output of PI closed-loop control is a control quantity formed by a linear combination, when the system needs to start decelerating, the initial quantity of PI closed-loop control output will be very small. Usually, the deceleration corresponding to this small initial quantity is less than the minimum critical value of the deceleration area for opening the hydraulic brake valve, that is, the deceleration area of ​​the hydraulic brake valve cannot be opened. In this process, the vehicle is still moving in an undecelerated state. The PI closed-loop control needs to re-determine the output deceleration based on the feedback of the latest vehicle information, and expects the motion state of the vehicle to be the motion state after deceleration according to the initial deceleration. At the same time, there is still a possibility that the output deceleration value is too small to open the deceleration area of ​​the hydraulic brake valve. In the process of PI closed-loop control re-determining the control output, if the time lasts for a long time, it will cause speed overshoot, which will cause great safety hazards during vehicle driving.

[0037] To solve the above problems, refer to Figure 1 The present application embodiment provides a method for controlling braking of an unmanned vehicle, comprising:

[0038] 101. During the driving process of the unmanned vehicle, the braking signal output by the PI closed-loop control is detected according to a preset period, and after the braking signal is detected, the corresponding logical braking deceleration is obtained.

[0039] In this embodiment, when the unmanned vehicle needs to decelerate during driving, the PI closed-loop control outputs a braking signal to control the unmanned vehicle to decelerate. In the prior art, under normal circumstances, the braking signal output by the PI closed-loop control will be sent to the vehicle-mounted control terminal, and the vehicle-mounted control terminal will send a deceleration signal to the hydraulic valve. The vehicle-mounted control terminal can detect the braking signal output by the PI closed-loop control according to a preset period, and after the braking signal is detected, the corresponding logical braking deceleration is obtained, and the logical braking deceleration includes a specific deceleration value. The vehicle-mounted control terminal can send a deceleration signal to the hydraulic valve according to the specific deceleration value.

[0040] 102. Compare the logical braking deceleration with the predetermined overriding braking deceleration, and send the larger braking deceleration as the output deceleration to the hydraulic brake valve.

[0041] Since the vehicle-mounted control terminal sends a deceleration signal to the hydraulic valve and there is a situation where the deceleration area of ​​the hydraulic brake valve cannot be opened, in the embodiment of the present application, an overriding braking deceleration is pre-set, and the overriding braking deceleration can be stored in the vehicle-mounted control terminal. After the logical braking deceleration is obtained, the logical braking deceleration can be compared with the predetermined overriding braking deceleration, and the larger braking deceleration is sent to the hydraulic brake valve as the output deceleration. The logical braking deceleration in this embodiment can open the deceleration area of ​​the hydraulic brake valve, for example, it can be the critical value of the deceleration area of ​​the hydraulic brake valve to open the deceleration area of ​​the hydraulic brake valve, or it can be slightly larger than the critical value to avoid the initial deceleration being too large and affecting the transportation efficiency.

[0042] 103. After detecting that the hydraulic brake valve is opened, the PI closed-loop control adjusts the magnitude of the braking deceleration, and subsequently adjusts the magnitude of the braking force output by the hydraulic brake valve.

[0043] After the braking deceleration is sent to the hydraulic brake valve, the state of the hydraulic brake valve can be detected. When it is detected that the hydraulic brake valve is open, the subsequent control of the vehicle can be taken over by the PI closed-loop control, which adjusts the size of the braking deceleration and subsequently adjusts the size of the braking force output by the hydraulic brake valve.

[0044] The unmanned vehicle braking control method disclosed in this embodiment introduces an over-authorized braking deceleration during the braking control process, and uses the larger of the logical braking deceleration and the over-authorized braking deceleration for braking control, which can ensure that the deceleration issued when deceleration is required can open the deceleration area of ​​the hydraulic brake valve, thereby avoiding braking failure caused by too small logical braking deceleration, greatly improving the braking success rate, and reducing various accidents caused by braking failure.

[0045] In order to ensure that hydraulic braking can intervene quickly when hydraulic braking is needed, quickly bypass the dead zone of hydraulic braking, open the hydraulic valve, and avoid the phenomenon of hydraulic braking intervening too slowly, the embodiment of the present application provides another unmanned vehicle braking control method. This method is triggered by the characteristics of the hydraulic braking dead zone, and designs a way of overriding hydraulic braking intervention, which can achieve rapid hydraulic braking intervention, thereby ensuring that the problem of speed overshoot during small deceleration is avoided. When hydraulic braking intervention is needed, this method bypasses the deceleration calculated by PI closed-loop control and directly issues an initial deceleration. In order to ensure that the above method can be used on vehicles with different line control consistency, that is, it is suitable for opening the deceleration area of ​​the vehicle's hydraulic brake valve, and detecting the wheel-end brake pressure at the same time. When the wheel-end brake pressure is detected, the overriding logic jumps out, and the target deceleration is adjusted using PI closed-loop control, see Figure 2 , the method comprising:

[0046] 201. During the driving of the driverless car, a braking signal output by the PI closed-loop control is detected according to a preset period, and after the braking signal is detected, 202 is executed.

[0047] In this embodiment, the preset period may be, for example, 0.3s or 0.5s, which may be set according to actual needs and is not specifically limited here.

[0048] 202. Determine whether the hydraulic brake is on. If the hydraulic brake is not on, execute 203.

[0049] In some optional embodiments, it is possible but not limited to determine whether the hydraulic brake is on by the following process (not shown in the figure):

[0050] 2021. Obtaining axle brake pressure of autonomous vehicles.

[0051] Axle brake pressure refers to the pressure generated by the axle brake system during braking. Braking pressure is the force transmitted by the braking system to the brake (such as brake pads or brake drums) through the braking medium (such as hydraulic oil), which will slow down or stop the vehicle. The magnitude of the brake pressure directly affects the braking force. Generally, the greater the brake pressure, the greater the braking force. However, excessive brake pressure may cause the wheels to lock, affecting the braking effect and vehicle stability.

[0052] 2022. Compare the axle brake pressure with a preset pressure value. If the axle brake pressure is less than the preset pressure value, it is determined that the hydraulic brake is not open.

[0053] 203. Obtain the corresponding logical braking deceleration.

[0054] Logical braking deceleration refers to the ideal braking deceleration calculated by the logic control algorithm during the braking process of the vehicle. This deceleration is calculated by the vehicle control system by comprehensively considering factors such as the vehicle's current speed, load, road conditions, etc., in order to achieve the best braking effect and safety. However, the logical braking deceleration may not be able to open the deceleration area of ​​the hydraulic brake valve. At the same time, the hydraulic brake valves of different vehicles may be different, resulting in different deceleration critical values ​​for opening the deceleration area of ​​the hydraulic brake valve. In order to adapt to hydraulic brake valves with different deceleration critical values, this embodiment is mainly implemented through the following steps:

[0055] 204 . Determine whether the logical braking deceleration is less than a preset speed value. If the logical braking deceleration is less than the preset deceleration value, execute 205 .

[0056] 205. Calculate a dynamic compensation value according to the braking delay time and the preset basic deceleration.

[0057] The braking delay time is the time from when the hydraulic brake signal is triggered to the current moment. Since the initial overriding braking deceleration is less than the preset deceleration value, the deceleration area of ​​the pressure brake valve cannot be opened, that is, there is a delay in the braking of the vehicle, so a larger deceleration value needs to be output to control the vehicle.

[0058] In some optional embodiments, the formula a 增益 =Δa*Δt to calculate the dynamic compensation value, where a 增益 is the dynamic compensation value, Δa is the preset basic deceleration, and Δt is the braking delay time.

[0059] 206. Calculate the override braking deceleration according to the dynamic compensation value and the preset calibration value.

[0060] In some optional embodiments, the override braking deceleration is calculated based on the dynamic compensation value and the preset calibration value: According to the formula a1=a basic +a 增益 Calculate the dynamic compensation value, where a1 is the overriding braking deceleration, a basic is the preset calibration value, a 增益 is the dynamic compensation value.

[0061] Optional, a basic =0.3m / s 2 , and / or, Δa=0.1m / s 2 .

[0062] In addition, in some other embodiments, a basic It can be a predetermined universal overriding braking deceleration, that is, the initial overriding braking deceleration of all vehicles is a basic When the initial overriding braking deceleration cannot open the deceleration area of ​​the hydraulic brake valve, the formula a1 = a basic +a 增益 The overriding braking deceleration is updated, and at this time, a1 is the updated overriding braking deceleration.

[0063] 207. Compare the logical braking deceleration with the re-determined overriding braking deceleration, and send the larger braking deceleration as the output deceleration to the hydraulic brake valve. If the hydraulic brake valve is not detected to be open, enter 203, adjust the overriding braking deceleration, and compare it with the logical braking deceleration again until the hydraulic brake valve is opened.

[0064] 208. After detecting that the hydraulic brake valve is opened, the PI closed-loop control adjusts the magnitude of the braking deceleration, and subsequently adjusts the magnitude of the braking force output by the hydraulic brake valve.

[0065] To facilitate the reader's understanding, the following is a detailed description of the relevant technical details in the embodiments of the present application:

[0066] In the small braking deceleration scenario, the deceleration obtained by the PI control integration will be relatively small at the beginning. For unmanned mining vehicles, the hydraulic valve cannot be opened at a small deceleration, and the PI integral term can only be slowly superimposed. If the basic parameters are relatively small, the superposition of the integral terms will be relatively small. If the hydraulic valve cannot be opened continuously, the hydraulic brake cannot be intervened, and the speed cannot be reduced for a long time, resulting in a large speed steady-state deviation.

[0067] Based on this, the embodiment of the present application discloses a method of hydraulic brake overriding. When it is detected that hydraulic braking needs to be issued, the braking decelerations of two links will be compared, one is the deceleration a0 obtained by PI closed-loop control. The other is the overriding deceleration a1, which is calculated as follows:

[0068] a1=a basic +a 增益 , where: a basic is the calibration value. In this embodiment, a is set basic =0.3m / s2, a 增益 This is to ensure that vehicles with different line control consistency can achieve dynamic compensation values ​​for braking through this method.

[0069] a 增益 =Δa*Δt, where: Δa is the basic deceleration of dynamic compensation, which is a calibration value. In this embodiment, Δa=0.1m / s2 is set, and Δt is the time when the hydraulic brake is not opened.

[0070] Whether the hydraulic brake is on or not is determined by receiving the axle brake pressure fed back by the VCU. When the axle brake pressure is greater than the threshold (empirical value), it is considered that the hydraulic valve is open.

[0071] In order to ensure safety, when large braking is required, the override will not bring negative impact. When the brake is output, the deceleration of the two links is compared and the larger deceleration is output: a=max(a0,a1).

[0072] When hydraulic brake intervention is required, hydraulic brake override can be performed, the hydraulic brake valve can be opened in time, and then the closed loop can be used to adjust the actual braking force required, which can avoid the hydraulic valve being unable to open for a long time, and the phenomenon of long-term non-deceleration and speed overshoot caused by hydraulic brake intervention.

[0073] The unmanned vehicle braking control method disclosed in this embodiment introduces an overriding braking deceleration during the braking control process, and uses the larger of the logical braking deceleration and the overriding braking deceleration for braking control, wherein the overriding braking deceleration is dynamically determined according to the braking condition, has high precision and accuracy, and effectively avoids braking failure caused by too small logical braking deceleration, greatly improves the braking success rate, and reduces various accidents caused by braking failure.

[0074] In order to realize the above-mentioned driverless car braking control method, see Figure 3 The present application embodiment provides a driverless vehicle braking control device, comprising:

[0075] The brake signal monitoring module 31 is used to detect the brake signal output by the PI closed-loop control according to a preset period during the driving process of the unmanned vehicle, and obtain the corresponding logical brake deceleration after detecting the brake signal.

[0076] The output speed determination module 32 is used to compare the logical braking deceleration with the predetermined overriding braking deceleration, and send the larger braking deceleration as the output deceleration to the hydraulic brake valve.

[0077] The brake control module 33 is used to adjust the magnitude of the brake deceleration by PI closed-loop control after detecting that the hydraulic brake valve is opened, and subsequently adjust the magnitude of the braking force output by the hydraulic brake valve.

[0078] The unmanned vehicle braking control device disclosed in this embodiment introduces an over-authorized braking deceleration during the braking control process, and uses the larger of the logical braking deceleration and the over-authorized braking deceleration for braking control, thereby effectively avoiding braking failure caused by too small a logical braking deceleration, greatly improving the braking success rate, and reducing various accidents caused by braking failure.

[0079] As an improvement of the above embodiment, the present application embodiment provides another unmanned vehicle braking control device, see Figure 4 , the device comprises:

[0080] The brake signal monitoring module 41 is used to detect the brake signal output by the PI closed-loop control according to a preset period during the driving process of the unmanned vehicle, and obtain the corresponding logical brake deceleration after detecting the brake signal.

[0081] The output speed determination module 42 is used to compare the logical braking deceleration with the predetermined overriding braking deceleration, and send the larger braking deceleration as the output deceleration to the hydraulic brake valve.

[0082] The brake control module 43 is used to adjust the magnitude of the brake deceleration by PI closed-loop control after detecting that the hydraulic brake valve is opened, and subsequently adjust the magnitude of the braking force output by the hydraulic brake valve.

[0083] In some optional embodiments, the device further comprises:

[0084] The re-braking module 44 is used to adjust the overriding braking deceleration if the hydraulic brake valve is not detected to be opened, and compare it with the logical braking deceleration again until the hydraulic brake valve is opened.

[0085] In some optional embodiments, the brake signal monitoring module 41 is also used to determine whether the hydraulic brake is turned on; if the hydraulic brake is not turned on, the corresponding logical braking deceleration is obtained, specifically, the axle brake pressure of the unmanned vehicle is obtained; the axle brake pressure is compared with a preset pressure value, if the axle brake pressure is less than the preset pressure value, it is determined that the hydraulic brake is not turned on.

[0086] In some optional embodiments, the output speed determination module 42 is also used to determine whether the logical braking deceleration is less than a preset speed value; if the logical braking deceleration is less than the preset deceleration value, the logical braking deceleration is compared with a predetermined override braking deceleration.

[0087] In some optional embodiments, the output speed determination module 42 is further used to calculate the overriding braking deceleration according to the dynamic compensation value and the preset calibration value. Specifically, the overriding braking deceleration is calculated according to the dynamic compensation value and the preset calibration value as follows: According to the formula a1=a basic +a 增益 Calculate the dynamic compensation value, where a1 is the overriding braking deceleration, a basic is the preset calibration value, a 增益 is the dynamic compensation value, a basic =0.3m / s 2 .

[0088] In some optional embodiments, the output speed determination module 42 is further used to calculate the dynamic compensation value according to the braking delay time and the preset basic deceleration. The braking delay time is a period of time from the triggering of the hydraulic braking signal to the current moment. Specifically, according to formula a 增益 =Δa*Δt to calculate the dynamic compensation value, where a 增益 is the dynamic compensation value, Δa is the preset basic deceleration, Δt is the braking delay time, Δa=0.1m / s 2 .

[0089] The unmanned vehicle braking control device disclosed in this embodiment introduces an overriding braking deceleration during the braking control process, wherein the overriding braking deceleration is dynamically determined according to the braking condition with high precision and accuracy, and the larger of the logical braking deceleration and the overriding braking deceleration is used for braking control, thereby effectively avoiding braking failure caused by too small logical braking deceleration, greatly improving the braking success rate, and reducing various accidents caused by braking failure.

[0090] Based on the same inventive concept, Figure 5 As shown, the present application also provides a driverless vehicle brake controller, comprising:

[0091] at least one processor 51 and at least one memory 52;

[0092] The memory stores executable instructions for the processor;

[0093] The processor is configured to execute the driverless vehicle braking control method provided in the above embodiment.

[0094] The unmanned vehicle braking controller provided in the embodiment of the present application stores executable instructions of the processor in a memory. When the executable instructions are executed, the processor can introduce an overriding braking deceleration during the braking control process, and use the larger of the logical braking deceleration and the overriding braking deceleration for braking control, wherein the overriding braking deceleration is dynamically determined according to the braking condition, has high precision and accuracy, and effectively avoids braking failure caused by too small logical braking deceleration, greatly improves the braking success rate, and reduces various accidents caused by braking failure.

[0095] It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0096] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

Claims

1. A braking control method for an unmanned vehicle, characterized in that: include: During the driving process of the driverless car, the braking signal output by the PI closed-loop control is detected according to a preset period, and after the braking signal is detected, the corresponding logical braking deceleration is obtained; Comparing the logical braking deceleration with a predetermined overriding braking deceleration, and sending the larger braking deceleration as the output deceleration to the hydraulic brake valve; After detecting that the hydraulic brake valve is open, the PI closed-loop control adjusts the magnitude of the braking deceleration, and subsequently adjusts the magnitude of the braking force output by the hydraulic brake valve.

2. The method according to claim 1, characterized in that: Also includes: If the hydraulic brake valve is not detected to be open, adjust the override braking deceleration and compare it with the logical braking deceleration again until the hydraulic brake valve opens.

3. The method according to claim 2, characterized in that: Before acquiring the corresponding logical braking deceleration, the method further includes: Determine whether the hydraulic brake is on; If the hydraulic brake is not on, the corresponding logical brake deceleration is obtained.

4. The method according to claim 3, characterized in that: Determining whether the hydraulic brake is on includes: Obtaining axle brake pressure of the driverless vehicle; The axle brake pressure is compared with a preset pressure value, and if the axle brake pressure is less than the preset pressure value, it is determined that the hydraulic brake is not opened.

5. The method according to claim 4, characterized in that: Before comparing the logical braking deceleration with a predetermined overriding braking deceleration, the method further includes: Determining whether the logical braking deceleration is less than a preset speed value; If the logical braking deceleration is less than the preset speed value, the logical braking deceleration is compared with a predetermined overriding braking deceleration.

6. The method according to any one of claims 1 to 5, characterized in that: Before comparing the logical braking deceleration with a predetermined overriding braking deceleration, the method further includes: The overriding braking deceleration is calculated according to the dynamic compensation value and the preset calibration value.

7. The method according to claim 6, characterized in that: Before calculating the override braking deceleration according to the dynamic compensation value and the preset calibration value, the method further includes: The dynamic compensation value is calculated according to the braking delay time and the preset basic deceleration, wherein the braking delay time is a period of time from the triggering of the hydraulic braking signal to the current moment.

8. The method according to claim 7, characterized in that: The dynamic compensation value is calculated according to the braking delay time and the preset basic deceleration: The dynamic compensation value is calculated according to the following formula: a 增益 =Δa*Δt, where a 增益 is the dynamic compensation value, Δa is the preset basic deceleration, and Δt is the braking delay time.

9. The method according to claim 8, characterized in that: The overriding braking deceleration is calculated according to the dynamic compensation value and the preset calibration value: The dynamic compensation value is calculated according to the following formula: a 1 =a basic +a 增益 , where a 1 is the overriding braking deceleration, a basic is the preset calibration value, a 增益 is the dynamic compensation value.

10. The method according to claim 9, characterized in that: a basic The value is 0.3m / s 2 , and / or, Δa is 0.1m / s 2 .

11. A brake control device for an unmanned vehicle, characterized in that: include: The braking signal monitoring module is used to detect the braking signal output by the PI closed-loop control according to a preset period during the driving process of the unmanned vehicle, and obtain the corresponding logical braking deceleration after detecting the braking signal; An output speed determination module, used for comparing the logical braking deceleration with a predetermined overriding braking deceleration, and sending the larger braking deceleration as the output deceleration to the hydraulic brake valve; The brake control module is used to adjust the magnitude of the brake deceleration by PI closed-loop control after detecting that the hydraulic brake valve is opened, and subsequently adjust the magnitude of the braking force output by the hydraulic brake valve.

12. A brake controller for an unmanned vehicle, characterized in that: include: at least one processor and at least one memory; The memory stores executable instructions of the processor; The processor is configured to execute the unmanned vehicle braking control method according to any one of claims 1-10.

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