Automatic parking brake control system and method

Abstract

The invention relates to the technical field of automatic parking, in particular to an automatic parking brake control system and method.The automatic parking brake control system comprises a driving motor, a motor control module, a wheel speed acquisition module, a data operation module, a positioning module, a planning and decision module, a brake control module and a hydraulic brake system; on the basis of a traditional hydraulic braking system, motor torque and wheel speed parameters are read through a motor control module and a wheel speed acquisition module, vehicle running parameters are obtained through a data operation module, and then expected braking force and deceleration are given by a planning and decision module in combination with a positioning module and sent to a braking control module; and the brake control module controls the hydraulic brake system to realize automatic parking of the vehicle. According to the invention, monitoring of vehicle load data and deceleration is added, and automatic parking of the vehicle is controlled by combining the planning and decision module and the brake control module with specific data, so that the cost is low, and the parking efficiency and precision are obviously improved.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic parking, and in particular to an automatic parking brake control system and method. Background Art

[0002] With the increasing throughput of port containers, the transportation efficiency of port containers has become an important factor restricting the throughput of port containers. In the total throughput of port containers, the proportion of automated horizontal transportation throughput has gradually increased. Traditional automated horizontal transportation uses AGV (Automated Guided Vehicle) automatic guided transport vehicles. AGV is a transport vehicle equipped with electromagnetic, optical or other automatic guidance devices, which can travel along the specified guidance path and has safety protection and various transfer functions. IGV (Intelligent Guided Vehicle) is a new concept proposed in recent years. Compared with traditional AGV, IGV is more flexible, does not need to rely on any fixed markers to travel, and has flexible and changeable paths, which can be flexibly scheduled according to actual production needs.

[0003] Port container transport conditions require high accuracy and efficiency in vehicle parking, but currently most IGV models achieve vehicle parking by controlling power input, which mainly controls the vehicle braking force by monitoring the brake cylinder pressure, thereby indirectly controlling the braking distance and vehicle speed. Due to the lack of vehicle load data and monitoring of deceleration, the control of braking distance is not accurate, resulting in repeated vehicle starts and stops, slow parking speed, low work efficiency, and inability to achieve accurate parking. Therefore, how to achieve fast and accurate automatic parking of vehicles is an urgent problem that IGV flatbed trucks need to solve. Summary of the invention

[0004] The present invention provides an automatic parking brake control system and method, which are used to solve the defect that the IGV flatbed vehicle in the prior art cannot accurately control the braking distance and cannot achieve precise parking, and realize high-efficiency and high-precision automatic parking of the vehicle.

[0005] The present invention provides an automatic parking brake control system, comprising a drive motor, a motor control module, a wheel speed acquisition module, a data calculation module, a positioning module, a planning and decision module, a brake control module and a hydraulic brake system, wherein the drive motor is used to drive the vehicle to move; the motor control module is connected to and controls the drive motor; the wheel speed acquisition module is used to collect the wheel speed of the vehicle during movement; the data calculation module is respectively connected to the motor control module and the wheel speed acquisition module, and is used to obtain the current vehicle speed, vehicle load and road adhesion coefficient of the vehicle; the positioning module is used to obtain the current position of the vehicle; the planning and decision module is respectively connected to the data calculation module and the positioning module, and formulates a braking strategy based on the current position of the vehicle and the vehicle speed, vehicle load and road adhesion coefficient of the vehicle; the brake control module is connected to the planning and decision module, and is used to receive the braking strategy of the planning and decision module and generate a control instruction; the hydraulic brake system is connected to the brake control module, and is used to receive the control instruction of the brake control module and execute vehicle braking.

[0006] According to an automatic parking brake control system provided by the present invention, the hydraulic brake system includes a hydraulic oil tank, a power pump, a brake accumulator, a service brake unit and a parking brake unit, wherein the power pump is connected to the hydraulic oil tank; the brake accumulator is connected to the power pump through a brake accumulator valve group; the service brake unit includes at least four service brake cylinders, which are respectively used for braking the four wheels of the vehicle during driving, and the service brake cylinders are connected to the brake accumulator through a service brake distribution module; the parking brake unit includes at least two parking brake cylinders, which are respectively used for braking the two rear wheels of the vehicle after parking, and the parking brake cylinders are connected to the brake accumulator; the power pump, the service brake cylinder, the service brake distribution module, and the parking brake cylinder are respectively connected to the brake control module to realize the control of the hydraulic brake system by the brake control module.

[0007] According to an automatic parking brake control system provided by the present invention, the brake accumulator valve group and the service brake distribution module are both provided with pressure sensors, and the pressure sensors are connected to the brake control module.

[0008] According to an automatic parking brake control system provided by the present invention, a proportional brake valve group is connected between the service brake distribution module and the brake accumulator, a parking brake valve group is connected between the parking brake cylinder and the brake accumulator, and the proportional brake valve group and the parking brake valve group are respectively connected to the brake control module.

[0009] According to an automatic parking brake control system provided by the present invention, the service brake unit further comprises a drag ball valve, which is connected between the parking brake cylinder and the brake accumulator and is arranged in parallel with the parking brake valve group.

[0010] According to an automatic parking brake control system provided by the present invention, the parking brake cylinder adopts a spring energy storage cylinder, and the parking brake is realized by the output shaft of the brake motor. The parking brake cylinder includes a parking state and a parking release state. When the oil pressure in the cylinder increases, the spring in the cylinder is compressed, and the vehicle is in the parking release state. When the pressure in the cylinder decreases, the spring in the cylinder is stretched, and the vehicle is in the parking state.

[0011] According to an automatic parking brake control system provided by the present invention, the wheel speed acquisition module adopts an active wheel speed sensor.

[0012] The present invention further provides an automatic parking brake control method, which is applicable to any one of the automatic parking brake control systems described above, and comprises steps S1 to S3.

[0013] S1. Based on the torque information of the driving motor obtained by the motor control module and the vehicle wheel speed information obtained by the wheel speed acquisition module, the current vehicle speed, vehicle load and road adhesion coefficient of the vehicle are obtained through the data calculation module.

[0014] S2. Based on the current vehicle speed, vehicle load and road adhesion coefficient sent by the data calculation module, the vehicle braking strategy is determined by the planning and decision module in combination with the predetermined target position information and the vehicle current position information obtained by the positioning module.

[0015] S3. Receive the vehicle braking strategy determined by the planning and decision module through the braking control module, and control the hydraulic braking system to perform vehicle braking.

[0016] According to an automatic parking brake control method provided by the present invention, the process of the hydraulic brake system performing vehicle braking includes steps S31 to S33.

[0017] S31. Determine the expected deceleration and initial braking force of the vehicle through the planning and decision module, and send them to the braking control module.

[0018] S32: The brake control module controls the hydraulic brake system to brake the vehicle based on the initial braking force determined by the planning and decision module, and monitors and controls the actual deceleration so that the actual deceleration is within a set error range of the expected deceleration.

[0019] S33: When the planning and decision module monitors that the vehicle speed drops to zero or is lower than a set threshold and the vehicle reaches a predetermined target position, the braking control module controls the hydraulic braking system to park the vehicle.

[0020] According to an automatic parking brake control method provided by the present invention, the monitoring and controlling of the actual deceleration includes steps S321-S322.

[0021] S321. When the braking control module receives a braking force and a deceleration request, it responds to the initial braking force request first and obtains the actual deceleration of the vehicle.

[0022] S322. The brake control module controls the hydraulic brake system based on a logic threshold control method to increase, decrease or maintain the braking force, so as to adjust the actual deceleration of the vehicle until the actual deceleration reaches within a set error range of the expected deceleration.

[0023] The automatic parking brake control system and method provided by the present invention, based on the traditional hydraulic brake system, reads the motor torque and wheel speed parameters through the motor control module and the wheel speed acquisition module, obtains the vehicle driving parameters through the data calculation module, and then the planning and decision module combines the GPS system of the positioning module to give the expected braking force and deceleration and send them to the brake control module, and the brake control module controls the hydraulic brake system to realize automatic parking of the vehicle. The automatic parking brake control system of the present invention does not require expensive sensors such as laser radar, increases the monitoring of vehicle load data and deceleration, and realizes automatic parking control of the vehicle by combining specific data through the planning and decision module and the brake control module, with low cost. Compared with motor-controlled parking, the parking efficiency and accuracy of the automatic parking brake control system of the present invention are significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a flow chart of the automatic parking brake control system provided by the present invention.

[0026] Figure 2 It is a schematic diagram of the principle of the hydraulic brake system provided by the present invention.

[0027] Figure 3 It is a schematic diagram of the whole vehicle layout of the hydraulic brake system provided by the present invention.

[0028] Figure 4 It is a partially enlarged schematic diagram of the whole vehicle layout of the hydraulic brake system provided by the present invention.

[0029] Figure 5 It is a schematic diagram of the principle of the automatic parking brake control system provided by the present invention.

[0030] Figure numerals: 1. driving motor; 2. motor control module; 3. wheel speed acquisition module; 4. data calculation module; 5. positioning module; 6. planning and decision-making module; 7. braking control module; 8. hydraulic braking system; 81. hydraulic oil tank; 82. power pump; 83. brake accumulator; 84. brake accumulator valve group; 85. service brake unit; 851. service brake cylinder; 852. service brake distribution module; 853. proportional brake valve group; 86. parking brake unit; 861. parking brake cylinder; 862. parking brake valve group; 863. drag ball valve; 87. pressure sensor. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are 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 the present invention.

[0032] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present invention.

[0033] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0034] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0035] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0036] Combine the following Figures 1 to 5 The automatic parking brake control system and method of the present invention are described.

[0037] An embodiment of the present invention provides an automatic parking brake control system, see Figure 1 As shown, the automatic parking brake control system includes a drive motor 1, a motor control module 2, a wheel speed acquisition module 3, a data calculation module 4, a positioning module 5, a planning and decision module 6, a brake control module 7 and a hydraulic brake system 8, wherein the drive motor 1 is used to drive the vehicle to move; the motor control module 2 is connected to and controls the drive motor 1; the wheel speed acquisition module 3 is used to collect the wheel speed of the vehicle during movement; the data calculation module 4 is respectively connected to the motor control module 2 and the wheel speed acquisition module 3, and is used to obtain the current vehicle speed, vehicle load and road adhesion coefficient of the vehicle; the positioning module 5 is used to obtain the current position of the vehicle; the planning and decision module 6 is respectively connected to the data calculation module 4 and the positioning module 5, and formulates a braking strategy based on the current position of the vehicle and the vehicle speed, vehicle load and road adhesion coefficient of the vehicle; the brake control module 7 is connected to the planning and decision module 6, and is used to receive the braking strategy of the planning and decision module 6 and generate a control instruction; the hydraulic brake system 8 is connected to the brake control module 7, and is used to receive the control instruction of the brake control module 7 and execute vehicle braking.

[0038] It can be understood that the automatic parking brake control system of this embodiment, based on the traditional hydraulic brake system, reads the motor torque and wheel speed parameters through the motor control module 2 and the wheel speed acquisition module 3, obtains the vehicle driving parameters through the data calculation module 4, and then the planning and decision module 6 combines the GPS system of the positioning module 5 to give the expected braking force and deceleration and send them to the brake control module 7, and the brake control module 7 controls the hydraulic brake system 8 to realize automatic parking of the vehicle. The automatic parking brake control system of this embodiment does not require expensive sensors such as laser radar, but adds monitoring of vehicle load data and deceleration. The automatic parking of the vehicle is controlled by the planning and decision module 6 and the brake control module 7 in combination with specific data, which is low in cost. Compared with motor-controlled parking, the parking efficiency and accuracy of the automatic parking brake control system of this embodiment are significantly improved.

[0039] It should be understood that the present embodiment adopts a variety of modules to realize the corresponding functions, wherein the modules involved in acquisition, control, calculation, positioning, planning and decision-making are all collections of program statements (i.e., a collection of program codes and data structures) that can independently complete the corresponding functions. No specific limitation is made on the corresponding models and structures of the modules herein.

[0040] In some embodiments of the automatic parking brake control system of the present invention, see Figure 2 As shown, the hydraulic brake system 8 includes a hydraulic oil tank 81, a power pump 82, a brake accumulator 83, a service brake unit 85 and a parking brake unit 86, wherein the power pump 82 is connected to the hydraulic oil tank 81; the brake accumulator 83 is connected to the power pump 82 through the brake accumulator valve group 84; the service brake unit 85 includes at least four service brake cylinders 851, which are respectively used for braking the four wheels of the vehicle during driving, and the service brake cylinders 851 are connected to the brake accumulator 83 through the service brake distribution module 852; the parking brake unit 86 includes at least two parking brake cylinders 861, which are respectively used for braking the two rear wheels of the vehicle after parking, and the parking brake cylinders 861 are connected to the brake accumulator 83; the power pump 82, the service brake cylinder 851, the service brake distribution module 852, and the parking brake cylinder 861 are respectively connected to the brake control module 7 to realize the control of the hydraulic brake system 8 by the brake control module 7.

[0041] It can be understood that the power of the hydraulic brake system 8 in this embodiment comes from the hydraulic oil tank 81 and the power pump 82. The hydraulic oil tank 81 and the power pump 82 in this embodiment can be shared with the vehicle steering system. Figure 3 As shown, the various hydraulic control valve components designed in this embodiment are centrally arranged on the side of the vehicle, which can save pipeline length and vehicle space and reduce system costs.

[0042] Specifically, see Figure 3As shown, the hydraulic oil tank 81 is installed in front of the vehicle for ventilation and heat dissipation. The power pump 82 is installed near the hydraulic oil tank 81, and the brake accumulator 83 is installed near the control valve group, which can effectively reduce the length of the pipeline. The power pump 82, the hydraulic oil tank 81 and the control valve group are connected by a hose and a steel pipe, which is convenient for pipeline fixing and installation. Figure 2 As shown, the high-pressure oil from the power pump 82 enters the brake accumulator 83 (beams) after passing through the brake accumulator valve group 84. A one-way valve is set between the pipelines to prevent the oil from flowing back. The brake accumulator 83 can ensure the stability of the system pressure and relieve pressure shock. The brake accumulator 83 provides the stored hydraulic energy to the service brake unit 85 and the parking brake unit 86 to brake the vehicle. Among them, the service brake unit 85 is used to provide braking during driving. Since there are many service brake cylinders 851, they correspond to multiple running wheels of the vehicle (such as Figure 3 The eight running wheels shown in the figure), therefore, two service brake distribution modules 852 are required for distribution; the parking brake unit 86 is used for parking brake when parking.

[0043] Furthermore, the brake accumulator valve group 84 and the service brake distribution module 852 are both provided with a pressure sensor 87, and the pressure sensor 87 is connected to the brake control module 7. The pressure of the service brake cylinder 851 and the parking brake cylinder 861 can be monitored in real time through the pressure sensor 87, and fed back to the brake control module 7. At the same time, the pressure sensor 87 can also be installed on the brake accumulator valve group 84 to monitor the pressure of the entire hydraulic brake system in real time.

[0044] In some specific examples of the automatic parking brake control system of the present invention, a proportional brake valve group 853 is connected between the service brake distribution module 852 and the brake accumulator 83, a parking brake valve group 862 is connected between the parking brake cylinder 861 and the brake accumulator 83, and the proportional brake valve group 853 and the parking brake valve group 862 are respectively connected to the brake control module 7.

[0045] See also Figure 2 As shown, it can be understood that the proportional brake valve group 853 can control the brake pressure of the service brake cylinders 851 (eight) through the electric control signal to achieve the functions of pressurization, decompression and pressure maintenance. Since there are many service brake cylinders 851, the brake distribution module 852 (two) is required for distribution. The brake distribution module 852 is equipped with a pressure sensor 87, which can monitor the pressure of the service brake cylinder 851 in real time. The parking brake valve group 862 can control the decompression and pressurization of the parking brake cylinder 861 through the electric control signal to achieve the purpose of parking and releasing parking.

[0046] In some specific examples of the automatic parking brake control system of the present invention, the service brake unit 85 further includes a drag ball valve 863 , which is connected between the parking brake cylinder 861 and the brake accumulator 83 and is arranged in parallel with the parking brake valve group 862 .

[0047] It is understandable that by adding the drag ball valve 863, the purpose of manually releasing the parking can be achieved in the case of failure of the electronic control system. Among them, the parking brake unit 86 of the vehicle adopts a disc brake, and the parking brake can be realized by the output shaft of the brake motor. The parking brake cylinder 861 adopts a spring energy storage cylinder, and realizes the parking brake through the output shaft of the brake motor. The parking brake cylinder 861 includes a parking state and a parking release state. When the oil pressure in the cylinder increases, the spring in the cylinder is compressed, and the vehicle is in the parking release state. When the pressure in the cylinder decreases, the spring in the cylinder is stretched, and the vehicle is in the parking state. Through this characteristic of the parking brake cylinder 861, automatic parking can be achieved when the vehicle pipeline fails, reducing the risk of collision. When the electronic control system fails, the hydraulic control valve of the parking brake valve group 862 will return to the initial position, and the vehicle is in the parking state. This structural design can reduce the risk of vehicle collision after the electronic control system fails.

[0048] See also Figure 3 As shown, the brake hose between the brake distribution module 852 and the service brake cylinder 851 passes through the frame through a plate joint, and the plate joint is assembled on the center plane of the axle, which can effectively reduce the swing amplitude of the pipeline when the vehicle turns. Figure 4 As shown, the brake accumulator valve group 84, the proportional brake valve group 853, the parking brake valve group 862 and the drag ball valve 863 are centrally arranged on the right side of the vehicle, which can reduce the length of the pipeline and facilitate maintenance and inspection. The drag ball valve is installed close to the outer side of the frame for easy manual operation.

[0049] In other embodiments of the automatic parking brake control system of the present invention, the wheel speed acquisition module 3 uses an active wheel speed sensor. It is understandable that the wheel speed acquisition module 3 uses an active wheel speed sensor, which has more accurate data acquisition and more stable signals at low speeds than a passive wheel speed sensor, and is more suitable for unmanned flatbed vehicles traveling at low speeds and braking conditions.

[0050] On the other hand, the present invention further provides an automatic parking brake control method. The automatic parking brake control method provided by the present invention is described below. The automatic parking brake control method described below and the automatic parking brake control system described above can be referred to each other.

[0051] An embodiment of the present invention provides an automatic parking brake control method, which is applicable to any of the automatic parking brake control systems described above. Figure 5As shown, the automatic parking brake control method of this embodiment includes the following steps S1-S3.

[0052] S1. Based on the torque information of the driving motor 1 obtained by the motor control module 2 and the vehicle wheel speed information obtained by the wheel speed acquisition module 3, the current vehicle speed, vehicle load and road adhesion coefficient of the vehicle are obtained through the data calculation module 4.

[0053] Specifically, the wheel speed information of the vehicle at the start-up stage is monitored by the wheel speed acquisition module 3 to obtain the vehicle speed and acceleration. The vehicle load can be calculated by combining the torque information of the drive motor 1 obtained by the motor control module 2. Since the motor torque and acceleration of the vehicle are constantly changing when the vehicle starts, multiple sets of vehicle load data will be obtained. The data calculation module 4 intercepts the data of the stable segment and then processes the data by interpolation to obtain the vehicle load data closest to the actual situation. The wheel speed information of the vehicle during braking is monitored by the wheel speed acquisition module 3 to obtain the deceleration, and the real-time position of the vehicle is obtained by the positioning module 5 to calculate the slip rate. The road adhesion coefficient can be determined by combining the braking force and the vehicle load. When the vehicle travels to a low-adhesion-coefficient road surface, the braking force and slip rate of the vehicle during braking are monitored to identify the size of the road adhesion coefficient, and then identify the special road conditions in rainy and snowy weather, so that the planning and decision module 6 can more accurately control the braking distance to reduce the risk of collision.

[0054] S2. Based on the current vehicle speed, vehicle load and road adhesion coefficient sent by the data calculation module 4, the vehicle braking strategy is determined by the planning and decision module 6 in combination with the predetermined target position information and the vehicle current position information obtained by the positioning module 5.

[0055] Specifically, the planning and decision module 6 can obtain the current position of the vehicle itself through the configured positioning module 5 (GPS system), and then determine the expected braking force and deceleration based on the predetermined target position information according to the current vehicle speed, road adhesion coefficient and vehicle load, so as to facilitate the braking force adjustment through the braking control module 7 and control the vehicle to accurately park at the target position.

[0056] S3. The vehicle braking strategy determined by the planning and decision module 6 is received through the braking control module 7. Meanwhile, the planning and decision module 6 disconnects the power input of the driving motor 1 through the motor control module 2. The braking control module 7 controls the hydraulic braking system 8 to perform vehicle braking.

[0057] Specifically, the process of the hydraulic brake system 8 performing vehicle braking includes the following steps S31 to S33.

[0058] S31 , determining the expected deceleration and initial braking force of the vehicle through the planning and decision module 6 , and sending them to the braking control module 7 .

[0059] S32, the braking control module 7 controls the hydraulic braking system 8 to brake the vehicle based on the initial braking force determined by the planning and decision module 6, and monitors and controls the actual deceleration so that the actual deceleration is within the set error range of the expected deceleration.

[0060] Monitoring and controlling the actual deceleration includes steps S321-S322.

[0061] S321, when the brake control module 7 receives the braking force and deceleration request, it responds to the initial braking force request first and obtains the actual deceleration of the vehicle.

[0062] S322, the brake control module 7 controls the hydraulic brake system 8 based on the logic threshold control method to increase, reduce or maintain the braking force (by adjusting the hydraulic control valve in the hydraulic brake system 8, the step-by-step pressure increase, pressure reduction and pressure maintenance of each brake cylinder can be achieved to achieve the functions of increasing, reducing and maintaining the braking force), so as to adjust the actual deceleration of the vehicle until the actual deceleration reaches the set error range of the expected deceleration. In actual work, the brake control module 7 gives priority to responding to the braking force request, and then monitors the actual deceleration, and controls the actual deceleration within the range of the expected deceleration through the threshold control method.

[0063] S33: When the planning and decision module 6 monitors that the vehicle speed drops to zero or is lower than a set threshold and the vehicle reaches a predetermined target position, the braking control module 7 controls the hydraulic braking system 8 to park the vehicle.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. 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. An automatic parking brake control system, characterized in that: include: A driving motor (1), used to drive the vehicle to move; A motor control module (2), connected to and controlling the drive motor (1); A wheel speed acquisition module (3), used to acquire the wheel speed of the vehicle during movement; A data operation module (4) is connected to the motor control module (2) and the wheel speed acquisition module (3) respectively, and is used to obtain the current vehicle speed, vehicle load and road adhesion coefficient of the vehicle; A positioning module (5), used to obtain the current position of the vehicle; A planning and decision module (6) is connected to the data operation module (4) and the positioning module (5) respectively, and formulates a braking strategy based on the current position of the vehicle and the vehicle speed, vehicle load and road adhesion coefficient; A braking control module (7), connected to the planning and decision module (6), and configured to receive the braking strategy of the planning and decision module (6) and generate a control instruction; A hydraulic brake system (8) is connected to the brake control module (7) and is used to receive control instructions from the brake control module (7) and execute vehicle braking.

2. The automatic parking brake control system according to claim 1, characterized in that: The hydraulic brake system (8) comprises: Hydraulic oil tank (81); A power pump (82), connected to the hydraulic oil tank (81); A brake accumulator (83), the brake accumulator (83) being connected to the power pump (82) via a brake accumulator valve group (84); A service brake unit (85) comprising at least four service brake oil cylinders (851) respectively used for braking the four wheels of the vehicle during driving, wherein the service brake oil cylinders (851) are connected to the brake accumulator (83) via a service brake distribution module (852); A parking brake unit (86), comprising at least two parking brake oil cylinders (861), respectively used for braking two rear wheels of the vehicle after parking, wherein the parking brake oil cylinders (861) are connected to the brake accumulator (83); The power pump (82), the service brake oil cylinder (851), the service brake distribution module (852), and the parking brake oil cylinder (861) are respectively connected to the brake control module (7) to enable the brake control module (7) to control the hydraulic brake system (8).

3. The automatic parking brake control system according to claim 2, characterized in that: The brake accumulator valve group (84) and the service brake distribution module (852) are both provided with a pressure sensor (87), and the pressure sensor (87) is connected to the brake control module (7).

4. The automatic parking brake control system according to claim 3, characterized in that: A proportional brake valve group (853) is connected between the service brake distribution module (852) and the brake accumulator (83), a parking brake valve group (862) is connected between the parking brake cylinder (861) and the brake accumulator (83), and the proportional brake valve group (853) and the parking brake valve group (862) are respectively connected to the brake control module (7).

5. The automatic parking brake control system according to claim 4, characterized in that: The service brake unit (85) further comprises a drag ball valve (863), wherein the drag ball valve (863) is connected between the parking brake oil cylinder (861) and the brake accumulator (83), and is arranged in parallel with the parking brake valve group (862).

6. The automatic parking brake control system according to claim 2, characterized in that: The parking brake cylinder (861) adopts a spring energy storage cylinder and realizes parking braking through the output shaft of the brake motor. The parking brake cylinder (861) includes a parking state and a parking release state. When the oil pressure in the cylinder increases, the spring in the cylinder is compressed, and the vehicle is in the parking release state. When the pressure in the cylinder decreases, the spring in the cylinder is stretched, and the vehicle is in the parking state.

7. The automatic parking brake control system according to any one of claims 1 to 6, characterized in that: The wheel speed acquisition module (3) adopts an active wheel speed sensor.

8. An automatic parking brake control method, characterized in that: The automatic parking brake control system according to any one of claims 1 to 7 comprises: Based on the torque information of the drive motor (1) obtained by the motor control module (2) and the vehicle wheel speed information obtained by the wheel speed acquisition module (3), the current vehicle speed, vehicle load and road adhesion coefficient of the vehicle are obtained through the data calculation module (4); Based on the current vehicle speed, vehicle load and road adhesion coefficient sent by the data operation module (4), the vehicle braking strategy is determined by the planning and decision module (6) in combination with the predetermined target position information and the vehicle current position information obtained by the positioning module (5); The vehicle braking strategy determined by the planning and decision module (6) is received through the braking control module (7), and the hydraulic braking system (8) is controlled to execute vehicle braking.

9. The automatic parking brake control method according to claim 8, characterized in that: The process of the hydraulic brake system (8) performing vehicle braking comprises: Determining the expected deceleration and initial braking force of the vehicle through the planning and decision module (6), and sending them to the braking control module (7); The brake control module (7) controls the hydraulic brake system (8) to brake the vehicle based on the initial braking force determined by the planning and decision module (6), and monitors and controls the actual deceleration so that the actual deceleration reaches a set error range of the expected deceleration; When the planning and decision module (6) monitors that the vehicle speed drops to zero or is lower than a set threshold and the vehicle reaches a predetermined target position, the braking control module (7) controls the hydraulic braking system (8) to park the vehicle.

10. The automatic parking brake control method according to claim 9, characterized in that: The monitoring and controlling of the actual deceleration includes: When the braking control module (7) receives a braking force and a deceleration request, it responds to the initial braking force request first and obtains the actual deceleration of the vehicle; The brake control module (7) controls the hydraulic brake system (8) based on a logic threshold control method to increase, decrease or maintain the braking force, so as to adjust the actual deceleration of the vehicle until the actual deceleration reaches within a set error range of the expected deceleration.

Images