Unmanned container truck and braking system thereof

Abstract

The invention provides a braking system of an unmanned container truck, which comprises four pressure control modules respectively connected with four axle braking air chambers; the first energy storage device is connected with the pressure control modules corresponding to the first axle and the fourth axle through a first group of symmetrical air paths, so that the response time of the first axle and the fourth axle for receiving brake air pressure is the same; the first axle and the corresponding gas circuit thereof, and the fourth axle and the corresponding gas circuit thereof form a first brake unit; the second energy storage device is connected with the pressure control modules corresponding to the second axle and the third axle through a second group of symmetrical air paths, so that the response time of the second axle and the third axle for receiving the brake air pressure is the same; and the second axle and the corresponding gas circuit thereof, and the third axle and the corresponding gas circuit thereof form a second brake unit. Regardless of advancing or retreating, the response time is consistent, the response time difference caused by the change of the driving direction is eliminated, and the problem of inconsistent braking deceleration control precision is solved.

Description

Technical Field

[0001] The present application relates to the field of brake control technology, and in particular to an unmanned container truck and a brake system thereof. Background Art

[0002] The braking system design for automated guided vehicles (AGVs) operating in ports currently utilizes the mature dual-circuit pneumatic braking system found in conventional commercial vehicles. This system typically utilizes independent energy supply for the front and rear axles, with the first energy storage device providing brake pressure for the first and second axles, and the second energy storage device providing brake pressure for the third and fourth axles.

[0003] Since a vehicle typically steers in the front half and drives in the rear, there are inherent differences in the physical structure of the front and rear halves, including differences in air line length, component placement, and pipeline routing. This results in significant differences in the air pressure buildup time between the front and rear circuits during braking. Specifically, the braking response time for the front circuit (controlling the first and second axles) is T1, while the braking response time for the rear circuit (controlling the third and fourth axles) is T2. Due to structural factors, T1 and T2 are not equal. However, if unmanned container trucks traveling in both directions directly adopt this system, in unmanned container truck operations requiring frequent two-way travel, when the vehicle changes direction, the original front and rear axle functions are interchanged. The front axle, which originally had a response time of T1, becomes the rear axle, and the rear axle, which originally had a response time of T2, becomes the front axle. This role reversal of response time due to the change in driving direction directly leads to the inability to maintain consistent braking deceleration control accuracy of the vehicle in different driving directions, posing a serious safety hazard to unmanned driving operations that require high-precision parking and stable braking performance, and limiting the further improvement of the operating efficiency and reliability of unmanned container trucks.

[0004] Furthermore, existing systems suffer from inaccurate wheel speed signal acquisition at low speeds, and vehicle weight estimation relies on motor parameters and is significantly affected by road conditions, further exacerbating the unreliability of braking control. Therefore, a braking system that can adapt to bidirectional driving conditions and ensure consistent braking response and control accuracy is urgently needed. Summary of the Invention

[0005] An embodiment of the present application provides an unmanned container truck and its braking system to solve the technical problem that the existing pneumatic brake system has different response times due to the inherent structural differences between the front and rear circuits, and the unmanned container truck directly uses it will have inconsistent braking accuracy when driving in both directions.

[0006] In a first aspect, a braking system for an unmanned container truck is provided, comprising: four pressure control modules, which are respectively connected to the brake air chambers of the first axle, the second axle, the third axle and the fourth axle, so as to independently control the wheel brake air pressure of the corresponding axles; a first energy storage device, which is connected to the pressure control modules corresponding to the first axle and the fourth axle through a first group of symmetrical air paths, so that the response time of the first axle and the fourth axle to receiving the brake air pressure is the same; the first axle and its corresponding air path and the fourth axle and its corresponding air path form a first braking unit; a second energy storage device, which is connected to the pressure control modules corresponding to the second axle and the third axle through a second group of symmetrical air paths, so that the response time of the second axle and the third axle to receiving the brake air pressure is the same; the second axle and its corresponding air path and the third axle and its corresponding air path form a second braking unit.

[0007] In some embodiments, the pressure control modules of the first axle and the fourth axle independently control the brake air pressure of the left and right wheels of the first axle and the fourth axle respectively; the pressure control module controlling the second axle and the third axle is a dual-channel module, and the two dual-channel modules independently control the brake air pressure of the left and right wheels of the second axle and the third axle respectively.

[0008] In some embodiments, active wheel speed sensors are provided at the wheels of the first axle, the second axle, the third axle and the fourth axle, so as to output stable corresponding wheel speed signals when the vehicle is traveling at a low speed; the active wheel speed sensors include Hall sensors, and are connected to the ECU of the unmanned container truck.

[0009] Some embodiments further include a vehicle weight estimation system comprising a plurality of axle load sensors; A plurality of axle load sensors are arranged on each axle to detect the load of the unmanned container truck and estimate the mass of the unmanned container truck.

[0010] In some embodiments, the number of axle load sensors is twice the number of axles of the unmanned container truck, and the sensors are symmetrically arranged on both sides of the length direction of each axle of the unmanned container truck.

[0011] In some embodiments, the number of axle load sensors is the same as the number of axles of the unmanned container truck, and the axle load sensors are arranged in the middle of each axle of the unmanned container truck.

[0012] In some embodiments, the axle load sensor is a pendulum-type sensor; or, The axle load sensor is a strain gauge sensor.

[0013] In some embodiments, a redundant braking device is also included; the redundant braking control device includes a redundant energy storage device, a redundant control valve and a mechanical operating mechanism; the air inlet of the redundant control valve is connected to the redundant energy storage device, and the air outlet is connected to the control ports of four pressure control modules; the mechanical operating mechanism is connected to the control port of the redundant control valve, so as to supply air pressure to the wheel-end brake chamber by opening the redundant control valve when the control system fails.

[0014] In some embodiments, the redundant control valve is a BCA valve, and the mechanical operating mechanism is a foot valve; the foot valve is connected to the control port of the BCA valve via a mechanical connecting rod.

[0015] In a second aspect, the present application also provides an unmanned container truck, which applies the braking system of the unmanned container truck provided above.

[0016] The beneficial effects of the technical solution provided by this application include: The present application provides a braking system for an unmanned container truck. During the design and manufacture of an unmanned container truck, the axles are typically positioned symmetrically about the longitudinal center of the vehicle, typically with four axles. A core issue with the prior art is the unequal response time of the first brake unit (first and second axles) located in the front half of the unmanned container truck and the second brake unit (third and fourth axles) located in the rear half of the unmanned container truck. This leads to inconsistent deceleration control accuracy in different directions of travel due to the reversal of axle roles during bidirectional travel. The present application defines the first axle and its corresponding air circuit and the fourth axle and their corresponding air circuit as the first brake unit, and the second axle and its corresponding air circuit and the third axle and their corresponding air circuit as the second brake unit. By designing the first and second symmetrical air circuits, the response times of the first and fourth axles receiving brake air pressure are controlled to be identical, as are the response times of the second and third axles receiving brake air pressure. This ensures that the first and second brake units, symmetrically located on either side of the longitudinal center of the unmanned container truck, have identical braking response times. Regardless of whether the unmanned container truck is in the forward or reverse direction, the first axle and the fourth axle with the same braking response time both serve as the first axle and the fourth axle in the driving direction, and the second axle and the third axle with the same braking response time both serve as the second axle and the third axle in the driving direction. This eliminates the difference in braking response time caused by changes in driving direction and solves the problem of inconsistent braking deceleration control accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. 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 any creative work.

[0018] Figure 1 A schematic diagram of a four-axle braking system of the prior art provided in an embodiment of the present application; Figure 2 A schematic diagram of the braking system of an unmanned container truck provided in an embodiment of the present application; Figure 3 A schematic diagram of the output signal of the magnetoelectric wheel speed sensor provided in an embodiment of the present application; Figure 4 This is a schematic diagram of the output signal of the Hall-type wheel speed sensor provided in an embodiment of the present application.

[0019] In the figure: 1. First energy storage device; 2. Second energy storage device; 3. Single-channel module; 4. Dual-channel module; 5. Brake chamber; 6. Active wheel speed sensor; 7. ECU; 8. BCA valve; 9. Redundant energy storage device; 10. Foot valve; 11. First axle; 12. Second axle; 13. Third axle; 14. Fourth axle. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] In order to make the technical problem to be solved by this application clearer, the causes of the technical problem will be specifically analyzed below.

[0022] The existing system uses a passive wheel speed sensor (magnetoelectric type). Its working principle determines that the signal is unreliable in low-speed scenarios in ports. The specific reasons are as follows: the magnetoelectric sensor drives the gear to rotate through the wheel, cuts the permanent magnet to generate an alternating magnetic field, outputs an induced voltage, and realizes wheel speed detection. Its output voltage amplitude is proportional to the wheel speed; the braking control of unmanned container trucks in ports (such as precise parking and anti-lock braking) needs to calculate the slip rate based on the real-time wheel speed. At low speeds, the vehicle speed base is small, and a slight deviation in the wheel speed signal will cause the slip rate calculation error to be sharply amplified: if the wheel speed signal is lost, ECU7 may misjudge that the wheel is locked, and then mistakenly reduce the braking force, resulting in an increase in braking distance; if the signal is distorted, ECU7 cannot accurately calculate the deceleration, resulting in an imbalance in the braking force distribution, causing the vehicle body to deviate.

[0023] The existing system is only equipped with 4 wheel speed sensors and 4 solenoid valves, and cannot achieve multi-axis dynamic braking force distribution. The specific reasons are as follows: the existing system only monitors key axles (such as axle 1 and axle 4), and does not monitor the wheel speeds of axles 2 and 3, resulting in ECU7 being unable to obtain the dynamic parameters of all wheels; under complex working conditions, such as overloading, the center of gravity of the container is biased to one side, and the wheel speed of the unmonitored axle may reach the locking threshold first, but ECU7 cannot detect it, resulting in the braking force of the axle not being adjusted in time, causing the body to roll; the slip rate of all wheels cannot be calculated in real time, and the braking force distribution can only be based on a fixed ratio (such as 50% for the front axle and 50% for the rear axle), which cannot adapt to load changes. The solenoid valve has coarse control granularity and cannot independently adjust the braking force of a single wheel. The existing system uses one solenoid valve to control multiple groups of wheels, rather than independently controlling a single wheel. When a wheel tends to slip due to slippery road conditions, the solenoid valve needs to adjust the braking force of both wheels on that axle at the same time, causing the braking force of the wheels on normal roads to be misadjusted, exacerbating the imbalance of the braking force. When driving in both directions, the roles of the front and rear axles are swapped, and the control logic of the solenoid valve cannot dynamically adapt to the needs of the original front axle solenoid valve controlling the current rear axle, further amplifying the deviation in braking force distribution.

[0024] In the first aspect, the embodiment of the present application provides a braking system for an unmanned container truck, referring to Figures 1 to 4 , Figure 2 This is a schematic diagram of the braking system of an unmanned container truck provided in an embodiment of the present application. Figure 2 As shown, a braking system for an unmanned container truck includes: four pressure control modules, which are respectively connected to the brake air chambers 5 of the first axle 11, the second axle 12, the third axle 13 and the fourth axle 14, so as to independently control the wheel brake air pressure of the corresponding axles; a first energy storage device 1, which is connected to the pressure control modules corresponding to the first axle 11 and the fourth axle 14 through a first set of symmetrical air paths, so that the response time of the first axle 11 and the fourth axle 14 receiving the brake air pressure is the same; the first axle 11 and its corresponding air path and the fourth axle 14 and its corresponding air path form a first braking unit; a second energy storage device 2, which is connected to the pressure control modules corresponding to the second axle 12 and the third axle 13 through a second set of symmetrical air paths, so that the response time of the second axle 12 and the third axle 13 receiving the brake air pressure is the same; the second axle 12 and its corresponding air path and the third axle 13 and its corresponding air path form a second braking unit.

[0025] By setting up the system, wherein, as Figure 2As described above, A1, A2, A3, A4, and A5 are all air inlets, B1, B2, B3, B4, B5, B6, B7, and B8 are all air outlets, and C1, C2, C3, C4, and C5 are all control valves; when designing and manufacturing unmanned container trucks, the positions of the axles are generally designed symmetrically with respect to the longitudinal center of the vehicle, and generally there are four axles; the core contradiction of the existing technology is that the braking response time of the first brake unit (first axle 11 and second axle 12) located in the front half of the unmanned container truck is not equal to the braking response time of the second brake unit (third axle 13 and fourth axle 14) located in the rear half of the unmanned container truck, and the roles of the axle groups are interchanged during bidirectional driving, resulting in inconsistent deceleration control accuracy in different driving directions. This application defines the first axle 11 and its corresponding air circuit, and the fourth axle 14 and its corresponding air circuit as the first brake unit, and the second axle 12 and its corresponding air circuit, and the third axle 13 and its corresponding air circuit as the second brake unit. By designing the first and second sets of symmetrical air circuits, the first and fourth axles 11, 14, and the second axles 12, 13 are controlled to have the same response time when receiving brake air pressure, ensuring that the first and second brake units, symmetrically located on either side of the longitudinal center of the unmanned container truck, have the same braking response time. This ensures that, regardless of whether the unmanned container truck is moving forward or backward, the first and fourth axles 11, 14, with the same braking response time, function as the first and fourth axles in the direction of travel, and the second and third axles 12, 13, with the same braking response time, function as the second and third axles in the direction of travel. This eliminates the difference in braking response time caused by changes in driving direction and resolves the issue of inconsistent braking deceleration control accuracy.

[0026] In some preferred embodiments, the pressure control modules of the first axle 11 and the fourth axle 14 independently control the brake air pressure of the left and right wheels of the first axle 11 and the fourth axle 14 respectively; the pressure control module controlling the second axle 12 and the third axle 13 is a dual-channel module 4, and the two dual-channel modules 4 independently control the brake air pressure of the left and right wheels of the second axle 12 and the third axle 13 respectively.

[0027] It is to be known that the pressure control module controlling the first axle 11 and the fourth axle 14 can be a single-channel module 3 or a double-channel module 4, and in this application, the pressure control module controlling the first axle 11 and the fourth axle 14 is a single-channel module 3, which independently controls the brake air pressure of each axle of the first axle 11 and the fourth axle 14 through the ABS valve. For example, when the left wheels of the four axles encounter a wet and slippery road surface, the single-channel module can independently reduce the air pressure of the wheels to avoid affecting the wheels of the right wheels of the four axles and the first axle 11, thereby solving the disadvantages of whole axle adjustment. The double-channel module 4 controls the second axle 12 and the third axle 13, and each module can independently adjust the air pressure of the left and right wheels of the corresponding axle. For example, when the load of the left wheel of the second axle 12 is large and the load of the right wheel is small, the double-channel module 4 can provide higher air pressure to the left wheel to adapt to the common container unbalance load working condition in the port. This can avoid wheel lock, especially at low speed, and can accurately control the slip ratio in the optimal range to ensure the braking efficiency and the stability of the vehicle body.

[0028] In some preferred embodiments, a driven wheel speed sensor 6 is arranged at each wheel of the first axle 11, the second axle 12, the third axle 13 and the fourth axle 14 to output a stable corresponding wheel speed signal when the vehicle is running at low speed. The driven wheel speed sensor 6 includes a Hall sensor, and is connected with the ECU 7 of the unmanned truck.

[0029] In this embodiment, the existing passive wheel speed sensor (magneto-electric type) has unstable signals in low-speed scenarios, which leads to inaccurate wheel speed and slip ratio monitoring and affects the braking control accuracy. Therefore, it is proposed to configure a driven wheel speed sensor (Hall type) at each wheel, which is connected with the ECU 7 to realize real-time parameter calculation and braking pressure adjustment. The driven Hall sensor outputs a stable square wave signal through magnetic field change, which is not affected by the wheel speed, and can still maintain signal accuracy even in the low-speed range. The ECU 7 can calculate the slip ratio and deceleration based on the accurate wheel speed signal, and adjust the braking pressure of the corresponding wheel in real time: when the slip ratio exceeds the threshold value, the air pressure of the wheel is immediately reduced; when the slip ratio is insufficient, the air pressure is appropriately increased. For reference Figure 4 , which is a Hall type wheel speed sensor output signal diagram provided by the embodiment of the application, wherein the abscissa is time Time and the ordinate is current value I S , and T represents a period, and t is a period of time within a period; I H is the maximum value of the current value within T, I L is the minimum value of the current value within T. And Figure 3 is a magneto-electric type wheel speed sensor output signal diagram provided by the embodiment of the application, which is a passive type sensor commonly used in the prior art.

[0030] In some preferred embodiments, a vehicle weight estimation system is further included, which comprises a plurality of axle load sensors; The plurality of axle load sensors are arranged on the axles for detecting the load of the unmanned truck and estimating the mass of the unmanned truck.

[0031] In the embodiment, the axle load sensors are directly installed on the axles to detect the load through physical quantities, height changes or stress without relying on motor parameters and acceleration, completely avoiding the interference of road resistance; the plurality of axle load sensors are arranged to cover all the axles, rather than the prior art of estimating the whole vehicle by a single axle, so that the ECU 7 can obtain the axle load of each axle and then superimpose the preset chassis weight to accurately calculate the whole vehicle weight, avoiding the error caused by the insufficient representativeness of single axle data.

[0032] In some preferred embodiments, the number of axle load sensors is twice the number of axles of the unmanned truck, and the axle load sensors are symmetrically arranged on both sides of each axle of the unmanned truck in the length direction. In some preferred embodiments, the number of axle load sensors is the same as the number of axles of the unmanned truck, and the axle load sensors are arranged at the middle positions of each axle of the unmanned truck.

[0033] In the two embodiments, two specific configurations are proposed to solve the problem that the arrangement of the axle load sensors in the prior art affects the detection accuracy due to the load distribution. If a swing lever sensor is used, it is arranged at the middle position or both sides of the axle to detect the height change of the whole vehicle chassis relative to the axle. When the container is empty, the chassis height is high and the swing lever angle is small. When the container is full, the chassis height is low and the swing lever angle is large. The average axle load is calculated by the angle change. If a strain gauge sensor is used, it is arranged at the middle position of the axle corresponding to the stress part of the left and right leaf springs. The strain of the leaf spring caused by the load is detected, and the average axle load is outputted by combining the proportional relationship between the strain and the load.

[0034] In some preferred embodiments, a redundant braking device is further included. The redundant braking control device comprises a redundant energy storage device 9, a redundant control valve and a mechanical operating mechanism. The gas inlet of the redundant control valve is connected with the redundant energy storage device 9, and the gas outlet is connected with the control port of the four pressure control modules. The mechanical operating mechanism is connected with the control port of the redundant control valve, so as to supply the gas pressure to the wheel end brake chamber 5 by opening the redundant control valve when the control system fails.

[0035] In this embodiment, a traditional EBS system relies on a single air circuit network and electronic control system. If problems such as a leak in the main energy storage device, a malfunction in the ECU 7, or a stuck solenoid valve occur, brake pressure cannot be transmitted to the wheel ends, resulting in a loss of braking capability. In the densely populated and heavily equipped unmanned container trucking areas of ports, such failures could potentially lead to serious collisions. This system employs two redundant control valves, each corresponding to two symmetrical axles. One redundant control valve precisely connects to the pressure control modules for the first and fourth axles, while the other connects to the pressure control modules for the second and third axles. In the event of a control system failure, the air pressure output by the redundant control valves can flow along the air circuits to the corresponding axles, ensuring that the brake pressure for the first, second, third, and fourth axles can still be regulated. This allows for accurate control of the braking deceleration deviation during bidirectional driving even in the event of a control system failure. In the event of a control system failure, the redundant control valves open to supply air pressure to the wheel-end brake chambers 5, preventing failure of the main system control circuit.

[0036] In some preferred embodiments, the redundant control valve is a BCA valve 8, and the mechanical operating mechanism is a foot valve 10; the foot valve 10 is connected to the control port of the BCA valve 8 through a mechanical connecting rod, so that when the first energy storage device 1 and the second energy storage device 2 fail, the foot valve 10 can be operated to push the valve core of the BCA valve 8 to move, so that the air pressure of the redundant energy storage device 9 enters the brake air circuit network.

[0037] In this embodiment, when the electrical signal of the BCA valve 8 and the pressure control module fails, C1, C2, C3, C4, and C5 serving as control valves can also control the air pressure at the outlet of the solenoid valve; the BCA valve 8 will receive the axle load sensor and wheel speed sensor signals and communicate with the ECU. The BCA valve 8 is used as a redundant braking system. When the ECU fails, the BCA valve 8 can replace the control air brake system to prevent the vehicle from losing its braking ability; and when the vehicle's electronic control system fails, the foot valve 10 connected to the control port of the BCA valve 8 can control the opening of the B6 and B7 ports of the BCA valve 8. The B6 and B7 ports of the BCA valve 8 are connected to the control port of the pressure control module to control the increase in the wheel-end brake pressure, so that the vehicle can be stopped in an emergency.

[0038] On the second aspect, the present application also proposes an unmanned container truck, which applies the proposed braking system of the unmanned container truck.

[0039] The beneficial effects brought about by the present invention include: The present application proposes a braking system for an unmanned container truck, in which, when the unmanned container truck is designed and manufactured, the positions of the axles are generally designed symmetrically with respect to the longitudinal center of the vehicle, and the truck generally has four axles. The core contradiction of the existing technology is that the braking response time of the first brake unit (first axle 11 and second axle 12) located in the front half of the unmanned container truck is not equal to the braking response time of the second brake unit (third axle 13 and fourth axle 14) located in the rear half of the unmanned container truck. The roles of the axle groups are interchanged during bidirectional driving, resulting in inconsistent deceleration control accuracy in different driving directions. This application defines the first axle 11 and its corresponding air circuit, and the fourth axle 14 and its corresponding air circuit as the first brake unit, and the second axle 12 and its corresponding air circuit, and the third axle 13 and its corresponding air circuit as the second brake unit. By designing the first and second sets of symmetrical air circuits, the first and fourth axles 11, 14, and the second axles 12, 13 are controlled to have the same response time when receiving brake air pressure, ensuring that the first and second brake units, symmetrically located on either side of the longitudinal center of the unmanned container truck, have the same braking response time. This ensures that, regardless of whether the unmanned container truck is moving forward or backward, the first and fourth axles 11, 14, with the same braking response time, function as the first and fourth axles in the direction of travel, and the second and third axles 12, 13, with the same braking response time, function as the second and third axles in the direction of travel. This eliminates the difference in braking response time caused by changes in driving direction and resolves the issue of inconsistent braking deceleration control accuracy.

[0040] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0041] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit the "first", "second" and "third" to different types.

[0042] In the description of the embodiments of this application, the words "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0043] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0044] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0045] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, or the part that contributes to the existing technology, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of this application.

[0046] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A braking system for an unmanned container truck, characterized in that: It includes: Four pressure control modules, which are respectively connected to the brake air chambers (5) of the first axle (11), the second axle (12), the third axle (13) and the fourth axle (14), for independently controlling the wheel brake air pressures of the corresponding axles; A first energy storage device (1) is connected to the pressure control modules corresponding to the first axle (11) and the fourth axle (14) via a first set of symmetrical air paths, so that the response time of the first axle (11) and the fourth axle (14) receiving the brake air pressure is the same; the first axle (11) and its corresponding air path and the fourth axle (14) and its corresponding air path form a first brake unit; The second energy storage device (2) is connected to the pressure control modules corresponding to the second axle (12) and the third axle (13) via a second set of symmetrical air paths, so that the response time of the second axle (12) and the third axle (13) receiving the brake air pressure is the same; the second axle (12) and its corresponding air path and the third axle (13) and its corresponding air path form a second brake unit.

2. The braking system for an unmanned container truck according to claim 1, characterized in that: The pressure control modules of the first axle (11) and the fourth axle (14) independently control the brake air pressure of the left and right wheels of the first axle (11) and the fourth axle (14); The pressure control module for controlling the second axle (12) and the third axle (13) is a dual-channel module (4), and the two dual-channel modules (4) independently control the brake air pressure of the left and right wheels of the second axle (12) and the third axle (13).

3. The braking system for an unmanned container truck according to claim 1, characterized in that: Active wheel speed sensors (6) are provided at the wheels of each of the first axle (11), the second axle (12), the third axle (13) and the fourth axle (14), for outputting stable corresponding wheel speed signals when the vehicle is traveling at a low speed; The active wheel speed sensor (6) comprises a Hall sensor, and is connected to the ECU (7) of the unmanned container truck.

4. The braking system for an unmanned container truck according to claim 1, wherein: Also included is a vehicle weight estimation system comprising a plurality of axle load sensors; A plurality of axle load sensors are provided on each axle to detect the load of the unmanned container truck and estimate the mass of the unmanned container truck.

5. The braking system for an unmanned container truck according to claim 4, characterized in that: The number of the axle load sensors is twice the number of axles of the unmanned container truck, and they are symmetrically arranged on both sides of the length direction of each axle of the unmanned container truck.

6. The braking system for an unmanned container truck according to claim 4, characterized in that: The number of the axle load sensors is the same as the number of axles of the unmanned container truck, and the axle load sensors are arranged in the middle position of each axle of the unmanned container truck.

7. The braking system for an unmanned container truck according to claim 4, characterized in that: The axle load sensor is a rocker-type sensor; or The axle load sensor is a strain gauge sensor.

8. The braking system for an unmanned container truck according to claim 1, wherein: Also includes redundant braking devices; The redundant brake control device comprises a redundant energy storage device (9), a redundant control valve and a mechanical operating mechanism; an air inlet of the redundant control valve is connected to the redundant energy storage device (9), and an air outlet is connected to the control ports of the four pressure control modules; the mechanical operating mechanism is connected to the control port of the redundant control valve, so as to supply air pressure to the wheel end brake chamber (5) by opening the redundant control valve when a control system fails.

9. The braking system for an unmanned container truck according to claim 8, characterized in that: The redundant control valve is a BCA valve (8), and the mechanical operating mechanism is a foot valve (10); The foot valve (10) is connected to the control port of the BCA valve (8) via a mechanical connecting rod.

10. An unmanned container truck, characterized in that: It includes the braking system of the unmanned container truck according to any one of claims 1 to 9.

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