Vehicle Braking Control Method and System under Long Downhill Conditions

Abstract

The present invention discloses a vehicle braking control method and system under long downhill conditions. The method includes the following steps: obtaining the vehicle's slope driving condition and the vehicle's braking energy recovery attribute; when the vehicle does not have the braking energy recovery function or the vehicle has the braking energy recovery function but is in the energy recovery exit state, obtaining the vehicle's operating condition; when the vehicle's required deceleration is less than the preset deceleration and the temperature rise of the rear brake disc is less than the first preset temperature rise, controlling to cut off the hydraulic input of the front and rear wheels and enter the dynamic braking mode that preferentially brakes the rear wheels; obtaining the condition that satisfies the dynamic braking mode exit condition; when the dynamic braking mode exit condition is satisfied, controlling to exit the dynamic braking mode and enter the hydraulic braking mode of simultaneous braking of the front and rear wheels. The vehicle braking control method under long downhill conditions provided by this application effectively solves the problem that the temperature rise of the front brake disc is too fast relative to the rear brake disc, and avoids the excessive temperature rise of the front brake disc from affecting the braking effect.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle intelligent control, and particularly to a vehicle braking control method and system under long downhill conditions. Background Art

[0002] For a vehicle without a braking energy recovery function, the entire process relies on hydraulic braking to provide all the required deceleration; for a vehicle with a braking energy recovery function, when the vehicle speed is less than 10 km / h, the energy recovery exits, and hydraulic braking is required to provide all the required deceleration; for a vehicle with a braking energy recovery function, when the battery is fully charged, the entire process also relies on hydraulic braking to provide all the required deceleration. Under long downhill conditions of the vehicle, full reliance on hydraulic braking of both the front and rear wheels, and the braking force provided by the rear axle is about half less than that of the front axle. Therefore, the temperature rise of the front brake disc is higher than that of the rear brake disc, and the braking limit temperature will be reached faster. The brake fluid temperature is too high, affecting the braking effect. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the above background art and provide a vehicle braking control method and system under long downhill conditions.

[0004] In a first aspect, the present application provides a vehicle braking control method under long downhill conditions, including the following steps:

[0005] Obtain the vehicle's slope driving condition and the vehicle's braking energy recovery attribute;

[0006] When the vehicle does not have a braking energy recovery function or the vehicle has a braking energy recovery function but is in an energy recovery exit state, obtain the vehicle's operating condition;

[0007] When the vehicle's required deceleration is less than the preset deceleration and the temperature rise of the rear brake disc is less than the first preset temperature rise, control to cut off the hydraulic input of the front and rear wheels and enter a dynamic braking mode that preferentially brakes the rear wheels;

[0008] Obtain the condition under which the dynamic braking mode exit condition is satisfied;

[0009] When the dynamic braking mode exit condition is satisfied, control to exit the dynamic braking mode and enter a hydraulic braking mode with simultaneous braking of the front and rear wheels.

[0010] According to the first aspect, in a first possible implementation manner of the first aspect, the vehicle having a braking energy recovery function but being in an energy recovery exit state means that the vehicle is in a fully charged state or the vehicle speed is less than a second preset vehicle speed.

[0011] According to the first aspect, in the second possible implementation manner of the first aspect, before the step of controlling to cut off the hydraulic input of the front and rear wheels and enter the dynamic braking mode that preferentially brakes the rear wheels when the vehicle's required deceleration is less than the preset deceleration and the temperature rise of the rear wheel brake disc is less than the first preset temperature rise, the following steps are further included:

[0012] Control to increase the maximum braking force provided by the rear wheels.

[0013] According to the second possible implementation manner of the first aspect, in the third possible implementation manner of the first aspect, the step of controlling to increase the maximum braking force provided by the rear wheels specifically includes the following steps:

[0014] Request the air suspension controller to reduce the ground clearance.

[0015] According to the first aspect, in the fourth possible implementation manner of the first aspect, the exit condition of the dynamic braking mode is that the temperature rise of the vehicle's rear wheel brake disc is greater than the second preset temperature rise or the vehicle's braking required deceleration is greater than the preset deceleration.

[0016] According to the first aspect, in the fifth possible implementation manner of the first aspect, the step of controlling to exit the dynamic braking mode and enter the hydraulic braking mode with simultaneous braking of the front and rear wheels when the dynamic braking mode exit condition is satisfied specifically includes the following steps:

[0017] When the temperature rise of the vehicle's rear wheel brake disc is greater than the second preset temperature rise, control to execute the heat dissipation strategy for the rear brake disc and exit the dynamic braking mode and enter the hydraulic braking mode with simultaneous braking of the front and rear wheels.

[0018] According to the first aspect, in the sixth possible implementation manner of the first aspect, the step of controlling to execute the heat dissipation strategy for the rear brake disc specifically includes the following steps:

[0019] Request the air suspension controller to increase the ground clearance and increase the air cooling method to dissipate heat from the front wheel brake disc and the rear wheel brake disc.

[0020] Second aspect, the present application provides a braking control system under long downhill conditions, including:

[0021] A first acquisition module, configured to acquire the vehicle's slope driving condition and the vehicle's braking energy recovery attribute;

[0022] A second acquisition module, communicatively connected to the first acquisition module, configured to acquire the vehicle's operating condition when the vehicle does not have a braking energy recovery function or when the vehicle has a braking energy recovery function but is in an energy recovery exit state;

[0023] The first control module, communicatively connected to the second acquisition module, is configured to control the hydraulic input to the front and rear wheels to be cut off and enter a dynamic braking mode that preferentially brakes the rear wheels when the deceleration demanded by the vehicle during braking is less than a preset deceleration and the temperature rise of the rear wheel brake disc is less than a first preset temperature rise.

[0024] The third acquisition module is configured to acquire the operating conditions that satisfy the dynamic braking mode exit condition.

[0025] The second control module, communicatively connected to the third acquisition module, is configured to control the exit of the dynamic braking mode and enter a hydraulic braking mode in which the front and rear wheels brake simultaneously when the dynamic braking mode exit condition is satisfied.

[0026] According to the second aspect, in the first possible implementation manner of the second aspect, the braking control system under the long downhill condition further includes:

[0027] The rear wheel maximum braking force increasing control module is configured to increase the maximum braking force provided by the rear wheels.

[0028] According to the second aspect, in the second possible implementation manner of the second aspect, the second control module includes:

[0029] The control unit, communicatively connected to the third acquisition module, is configured to control the execution of the heat dissipation strategy for the rear brake disc and exit the dynamic braking mode to enter the hydraulic braking mode in which the front and rear wheels brake simultaneously when the temperature rise of the vehicle rear wheel brake disc is greater than a second preset temperature rise.

[0030] Compared with the prior art, the advantages of the present invention are as follows:

[0031] The vehicle braking control method under the long downhill condition provided by the present application controls the hydraulic input to the front and rear wheels to be cut off and preferentially performs dynamic braking on the rear wheels when the deceleration demanded by the vehicle is less than the preset deceleration and the temperature rise of the vehicle rear wheel brake disc is less than the first preset temperature rise. After the dynamic braking mode exit condition is satisfied, the dynamic braking mode is exited and the hydraulic braking mode in which the front and rear wheels brake simultaneously is entered, effectively solving the technical problem that the over-fast temperature rise of the front brake disc affects the braking effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is the flowchart of the vehicle braking control method under the long downhill condition provided by the embodiment of the present invention;

[0033] Figure 2 is the force diagram of the vehicle during braking;

[0034] Figure 3 is the force diagram of the vehicle under the slope driving condition;

[0035] Figure 4 is the functional module block diagram of the braking control system under the long downhill condition provided by the embodiment of the present invention. Detailed implementation manners

[0036] Now, specific embodiments of the present invention will be described in detail. Examples of the present invention are illustrated in the accompanying drawings. Although the present invention will be described in conjunction with specific embodiments, it will be understood that it is not intended to limit the present invention to the described embodiments. On the contrary, it is intended to cover modifications, variations, and equivalents included within the spirit and scope of the present invention as defined by the appended claims. It should be noted that the method steps described herein can all be implemented by any functional block or functional arrangement, and any functional block or functional arrangement can be implemented as a physical entity or a logical entity, or a combination of both.

[0037] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0038] Note: The examples to be introduced next are only a specific example and do not limit that the embodiments of the present invention must be the following specific steps, numerical values, conditions, data, sequences, etc. Those skilled in the art can use the concept of the present invention to construct more embodiments not mentioned in this specification by reading this specification.

[0039] When the vehicle is in a long downhill working condition and does not have a braking energy recovery function, or has a braking energy recovery function, but the vehicle is in a fully charged state or a braking energy recovery exit state where the vehicle speed is less than a preset vehicle speed, hydraulic braking is required. During hydraulic braking, especially in a long downhill working condition, since the front axle braking force is greater than the rear axle braking force, the temperature rise of the front brake disc is greater than that of the rear brake disc. When the temperature of the brake disc exceeds 700 °C, the temperature of the brake fluid exceeds 180 °C, and the braking effect decreases.

[0040] In view of this, the present application provides a vehicle braking control method under a long downhill working condition, effectively solving the technical problem that the temperature rise of the front brake disc is higher than that of the rear brake disc, affecting the braking effect.

[0041] Please refer to Figure 1 , the present application provides a vehicle braking control method under a long downhill working condition, including the following steps:

[0042] Step S1, obtaining the vehicle's slope running condition and the vehicle's braking energy recovery attribute;

[0043] Step S2, when the vehicle does not have a braking energy recovery function or the vehicle has a braking energy recovery function but is in an energy recovery exit state, obtaining the vehicle's operating condition;

[0044] Step S3, when the vehicle's required deceleration is less than a preset deceleration and the temperature rise of the rear wheel brake disc is less than a first preset temperature rise, controlling to cut off the hydraulic input of the front and rear wheels to enter a dynamic braking mode that preferentially brakes the rear wheels;

[0045] Step S4: Obtain the working condition where the dynamic braking mode exit condition is satisfied;

[0046] Step S5: When the dynamic braking mode exit condition is satisfied, control to exit the dynamic braking mode and enter the hydraulic braking mode with simultaneous front and rear wheel braking.

[0047] For the vehicle braking control method under long downhill conditions provided by this application, when it is necessary to brake the front and rear wheels, control to enter the dynamic braking mode with priority braking of the rear wheels to adapt to the fact that the braking force provided by the rear axle is approximately half less than that of the front axle. If braking simultaneously, the front brake disc will have too high a temperature rise relative to the rear brake disc and reach the brake failure or brake limit temperature in advance. However, in this application, by braking the rear wheels first and then entering the hydraulic braking mode with simultaneous front and rear wheel braking after the dynamic braking mode exit condition is satisfied, the temperature rise difference between the front and rear brake discs can be reduced, the braking time of the front and rear brake discs can be extended, and a better braking effect can be achieved.

[0048] In one embodiment, the vehicle braking energy recovery attribute includes that the vehicle has a braking energy recovery function and does not have a braking energy recovery function.

[0049] As described above, the long downhill condition means that the vehicle is in a downhill driving state and the driving distance is relatively long.

[0050] In one embodiment, the dynamic braking mode is to request the EPB controller to perform dynamic braking on the rear wheels.

[0051] In one embodiment, the vehicle having a braking energy recovery function but being in the energy recovery exit state includes the following two states:

[0052] First, the vehicle speed is less than the first preset vehicle speed, the energy recovery exits, and hydraulic braking is required to provide all the required deceleration;

[0053] Second, the vehicle has a braking energy recovery function but is in a fully charged state, and the energy recovery cannot be enabled, and hydraulic braking is required to provide all the required deceleration;

[0054] In addition to the above two states, vehicle braking demand deceleration can be provided through energy recovery. Specifically, when the battery is not fully charged and the vehicle speed is not less than the first preset vehicle speed, and the vehicle demand deceleration is less than the preset deceleration, motor reverse drag braking can be adopted while performing energy recovery, that is, braking energy recovery; when the battery is not fully charged and the deceleration is greater than the preset deceleration, hydraulic braking can be combined with braking energy recovery braking to provide the vehicle braking demand deceleration. Therefore, this application mainly conducts braking optimization design for the above two states to avoid excessive temperature rise of the front brake disc. When the temperature rise of the rear brake disc does not reach the braking limit temperature, the front brake disc reaches the braking limit temperature, affecting the braking effect during the long downhill driving of the vehicle, ensuring that the vehicle can safely and smoothly pass through the long downhill under the premise of achieving the required deceleration, and there will be no situation where the braking effect is better in the early stage during long downhill driving, meeting the required braking demand deceleration, and in the later stage, due to excessive temperature rise of the front brake disc reaching the braking limit temperature, the braking effect is poor and the required deceleration cannot be achieved, resulting in unsafe driving.

[0055] In one embodiment, the required deceleration is the braking demand deceleration for the vehicle to drive safely during long downhill driving.

[0056] In one embodiment, under the long downhill condition, according to test statistics, due to the relatively slow vehicle speed, the normal full - process deceleration ≤ 0.3g, and the deceleration > 0.3g under emergency braking conditions, the preset deceleration is 0.3g.

[0057] In one embodiment, when the temperature > 650°C, the friction coefficient of the brake pads will decrease by about 30%, and the friction pads will break off, affecting the braking effect. Under the long downhill condition, the braking limit temperature of the front brake disc is 700°C, and the corresponding braking limit temperature of the brake fluid is 180°C. The brake fluid will vaporize, resulting in a decrease in the braking effect and even failure. For vehicles with braking energy recovery, when the vehicle is fully charged or the vehicle speed < 10 km / h, and vehicles without braking energy recovery rely entirely on four - wheel hydraulic braking under the long downhill condition. Under the long downhill condition, the driver needs to keep stepping on the brakes to control the vehicle speed. Each time the brakes are applied, the temperature of the front and rear brake discs will continue to rise. When the temperature of the brake disc exceeds 650°C, the temperature of the brake fluid radiated into the brake caliper will rise to 180°C. Under the dual action, there will be a significant deterioration in the braking effect and even a risk of failure.

[0058] In one embodiment, in order to preferentially brake the rear wheels with a limited number to provide more temperature - rise buffer time for the braking temperature rise of the front brake disc, the vehicle braking control method under the long downhill condition provided by this application includes the following steps:

[0059] Obtain the vehicle's slope - driving condition and the vehicle's braking energy recovery attribute;

[0060] When the vehicle does not have a braking energy recovery function or when the vehicle has a braking energy recovery function but is in the energy recovery exit state, obtain the operating conditions of the vehicle;

[0061] Control to increase the maximum braking force provided by the rear wheels;

[0062] When the vehicle's required deceleration is less than the preset deceleration and the temperature rise of the rear wheel brake disc is less than the first preset temperature rise, control to cut off the hydraulic input of the front and rear wheels and enter the dynamic braking mode that preferentially brakes the rear wheels;

[0063] Obtain the operating conditions that meet the dynamic braking mode exit conditions;

[0064] When the dynamic braking mode exit conditions are met, control to exit the dynamic braking mode and enter the hydraulic braking mode where the front and rear wheels brake simultaneously.

[0065] In one embodiment, as Figure 2 shown, it is the force-bearing situation of the vehicle during braking on a horizontal road surface. The rolling resistance couple moment, air resistance, and inertial couple moment generated during the deceleration of the rotating mass of the vehicle are ignored in the figure. In addition, the process of the wheels rolling and slipping during braking is also ignored in the following analysis, and the adhesion coefficient only takes a fixed value ψ0. From Figure 2 it can be seen that taking the moment about the rear wheel ground contact point gives

[0066] F Z1 L = Gb + m ; In the formula, F Z1 is the normal reaction force of the ground on the front wheel, m is the vehicle mass, is the height of the vehicle's center of mass, is the vehicle deceleration, with the unit of m / s 2 , G is the vehicle gravity, and b is the distance from the vehicle's center of mass to the center line of the rear axle.

[0067] Please refer to Figure 3 , take the moment about the front wheel ground contact point, and we get:

[0068] F Z2 L = Ga - m ;

[0069] The rear axle load F Z2 = ;

[0070] The maximum deceleration that the rear wheels can provide = F Z2 * φ, where φ is the ground friction coefficient;

[0071] The deceleration that the rear wheel brake caliper EPB can provide , with a maximum of ;

[0072] The deceleration required by the vehicle is ;

[0073] where F Z2 is the normal reaction force of the ground on the rear wheels, m is the vehicle mass, is the height of the vehicle's center of mass, is the vehicle deceleration, with the unit of m / s 2 , G is the vehicle gravity, and a is the distance from the vehicle's center of mass to the center line of the front axle.

[0074] It can be seen from the force decomposition in the above figure that the greater the height of the vehicle's center of mass, the smaller the load on the rear wheels F Z2 , the greater the load on the front wheels F Z2 , and the maximum braking force provided by the rear wheels is F Z2* ψ 0， decreases the height of the center of mass. By reducing the ground clearance through the request for the air suspension controller, Hg decreases, and F Z2 increases, so that the height of the center of mass is reduced, and the maximum braking force provided by the rear wheels is increased to achieve preferential braking of the rear wheels, providing more temperature rise buffer time for the temperature rise of the front wheels during this braking process, and preventing them from reaching the temperature rise limit temperature first, which affects the braking effect and braking stability during this braking process.

[0075] In one embodiment, the condition for exiting the dynamic braking mode is that the temperature rise of the vehicle's rear wheel brake disc is greater than the second preset temperature rise or the vehicle braking demand deceleration is greater than the preset deceleration. Specifically, the vehicle braking control method under long downhill conditions provided in this application includes the following steps:

[0076] Obtain the vehicle's slope running condition and the vehicle's braking energy recovery attribute;

[0077] When the vehicle does not have a braking energy recovery function or the vehicle has a braking energy recovery function but is in the energy recovery exit state, obtain the vehicle's operating condition;

[0078] When the vehicle demand deceleration is less than the preset deceleration and the temperature rise of the rear wheel brake disc is less than the first preset temperature rise, control to cut off the hydraulic input of the front and rear wheels and enter the dynamic braking mode of preferential braking of the rear wheels;

[0079] Obtain the condition when the dynamic braking mode exit condition is satisfied;

[0080] When the temperature rise of the vehicle's rear wheel brake disc is greater than the second preset temperature rise T2 or the vehicle braking demand deceleration is greater than the preset deceleration, control to exit the dynamic braking mode and enter the hydraulic braking mode of simultaneous braking of the front and rear wheels.

[0081] In one embodiment, the second preset temperature rise is 300°C. According to the logic that the temperature rise of the rear brake disc is slower than that of the front brake disc during a single braking, EPB is used to perform dynamic braking on the rear wheels to provide the vehicle braking demand deceleration. When the temperature of the rear brake disc rises above 300°C, the EPB dynamic braking is exited, and the intelligent control unit outputs hydraulic pressure to brake the front and rear wheels simultaneously, so as to control the disadvantage of the fast temperature rise of the front wheels, ensure the braking effect, and reduce the temperature rise speed of the front wheels.

[0082] In one embodiment, the vehicle braking control method under long downhill conditions provided by the present application includes the following steps:

[0083] Obtain the vehicle driving condition on the slope and the vehicle braking energy recovery attribute;

[0084] When the vehicle does not have the braking energy recovery function or the vehicle has the braking energy recovery function but is in the energy recovery exit state, obtain the operating condition of the vehicle;

[0085] When the vehicle demand deceleration is less than the preset deceleration and the temperature rise of the rear brake disc is less than the first preset temperature rise, control to cut off the hydraulic input of the front and rear wheels and enter the dynamic braking mode that preferentially brakes the rear wheels;

[0086] Obtain the condition when the dynamic braking mode exit condition is satisfied;

[0087] When the temperature rise of the rear brake disc of the vehicle is greater than the second preset temperature rise, control to execute the heat dissipation strategy for the rear brake disc and exit the dynamic braking mode to enter the hydraulic braking mode of braking the front and rear wheels simultaneously, so as to reduce the temperature of the rear brake disc and avoid too high a temperature rise of the rear brake disc, and when the front and rear wheels brake simultaneously, the temperature rise of the rear brake disc reaches the braking limit temperature in advance.

[0088] In one embodiment, for the brake disc temperature rise formula, △t = Q / mC - P, where △t is the temperature rise, Q is the generated heat, m is the mass, C is the specific heat capacity, and P is the air-cooled heat dissipation. It can be seen that the specific heat capacity C remains unchanged and the heat Q continuously increases. The methods to reduce the temperature rise are, the first is to increase the mass m of the brake disc, and the second is to increase the air-cooled heat dissipation. When designing the whole vehicle, under the condition of meeting the braking effect, the mass of the brake disc should be reduced as much as possible. On the one hand, it can reduce the weight of the whole vehicle and improve the endurance, especially reduce the unsprung weight and improve the vehicle handling. On the other hand, it can reduce the cost. If considering the long downhill condition, which belongs to an abnormal working condition, it is necessary to greatly increase the weight of the front brake disc, and the development cost increases. Therefore, the present application mainly reduces the temperature rise of the rear brake disc when exiting the dynamic braking mode by increasing the air-cooled heat dissipation. Specifically, request the air suspension controller to increase the ground clearance and increase the air-cooled method to dissipate heat from the front brake disc and the rear brake disc.

[0089] Second aspect, please refer to Figure 4, this application provides a braking control system under long downhill conditions, including a first acquisition module 100, a second acquisition module 200, a first control module 300, a third acquisition module 400, and a second control module 500. The first acquisition module is used to acquire the vehicle's slope driving condition and the vehicle's braking energy recovery attribute; the second acquisition module is communicatively connected to the first acquisition module and is used to acquire the vehicle's operating condition when the vehicle does not have a braking energy recovery function or when the vehicle has a braking energy recovery function but is in an energy recovery exit state; the first control module is communicatively connected to the second acquisition module and is used to control the hydraulic input to the front and rear wheels to be cut off and enter a dynamic braking mode that preferentially brakes the rear wheels when the vehicle's braking demand deceleration is less than a preset deceleration and the temperature rise of the rear wheel brake disc is less than a first preset temperature rise; the third acquisition module is used to acquire the condition where the dynamic braking mode exit condition is satisfied; the second control module is communicatively connected to the third acquisition module and is used to control the exit of the dynamic braking mode and enter a hydraulic braking mode where the front and rear wheels brake simultaneously when the dynamic braking mode exit condition is satisfied.

[0090] In one embodiment, the first control module and the second control module are implemented as an intelligent integrated control unit. The intelligent integrated control unit is communicatively connected to the air suspension controller and the EPB, and the intelligent integrated control unit is used to request the air suspension controller to reduce or increase the ground clearance and is also used to request the EPB controller to perform dynamic braking on the rear wheels and a new type of braking.

[0091] For the braking control system under long downhill conditions provided by this application, when it is necessary to brake the front and rear wheels, it requests the EPB control to perform dynamic braking on the rear wheels to adapt to the fact that the braking force provided by the rear axle is approximately half less than that of the front axle. If braking simultaneously, the temperature rise of the front brake disc relative to the rear brake disc will be too high, reaching the brake failure or brake limitation temperature in advance. However, in this application, by preferentially braking the rear wheels and then entering a hydraulic braking mode where the front and rear wheels brake simultaneously after the dynamic braking mode exit condition is satisfied, the temperature rise difference between the front and rear brake discs is reduced, the braking time of the front and rear brake discs is extended, and a better braking effect is achieved.

[0092] In one embodiment, the second control module includes a control unit. The control unit is communicatively connected to the third acquisition module and is used to control the implementation of a heat dissipation strategy for the rear brake disc and exit the dynamic braking mode and enter a hydraulic braking mode where the front and rear wheels brake simultaneously when the temperature rise of the vehicle's rear wheel brake disc is greater than a second preset temperature rise.

[0093] Controlling the implementation of the heat dissipation strategy for the rear brake disc includes:

[0094] Requesting the air suspension controller to increase the ground clearance and increasing the air cooling method to dissipate heat from the front wheel brake disc and the rear wheel brake disc.

[0095] Based on the same inventive concept, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, all or part of the method steps of the above method are implemented.

[0096] The implementation of all or part of the processes in the above method of the present invention can also be completed by instructing relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above various method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0097] Based on the same inventive concept, an embodiment of the present application further provides an electronic device, including a memory and a processor. A computer program running on the processor is stored in the memory. When the processor executes the computer program, all or part of the method steps of the above method are implemented.

[0098] The so-called processor may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The processor is the control center of the computer device and connects various parts of the entire computer device through various interfaces and lines.

[0099] The memory can be used to store computer programs and / or modules. By running or executing the computer programs and / or modules stored in the memory, and by calling the data stored in the memory, the processor can implement various functions of the computer device. The memory mainly includes a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function (such as a sound playback function, an image playback function, etc.); the data storage area can store data created according to the use of the mobile phone (such as audio data, video data, etc.). In addition, the memory can include high-speed random access memory, and can also include non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a SmartMedia Card (SMC), a Secure Digital (SD) card, a Flash Card, at least one magnetic disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0100] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, a server, or a computer program product. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage and optical storage, etc.) containing computer-usable program code.

[0101] The present invention is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), servers, and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, and the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0102] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device implements the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0103] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus, so that a series of operation steps are executed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions for implementing the steps specified in one process or a plurality of processes and / or boxes Figure 1 in one flow or a plurality of flows and / or boxes Figure 1 in one box or a plurality of boxes.

[0104] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A vehicle braking control method under long downhill conditions, characterized in that, It includes the following steps: Obtain the vehicle's slope driving condition and the vehicle's braking energy recovery attribute; When the vehicle does not have the braking energy recovery function or the vehicle has the braking energy recovery function but is in the energy recovery exit state, obtain the vehicle's operating condition, where the vehicle having the braking energy recovery function but being in the energy recovery exit state means the vehicle is in a fully charged state or the vehicle speed is less than the second preset speed; Control to increase the maximum braking force provided by the rear wheels, specifically including: requesting the air suspension controller to reduce the ground clearance; When the vehicle's required deceleration is less than the preset deceleration and the temperature rise of the rear wheel brake disc is less than the first preset temperature rise, control to cut off the hydraulic input of the front and rear wheels and enter the dynamic braking mode that preferentially brakes the rear wheels; Obtain the condition that satisfies the dynamic braking mode exit condition; When the dynamic braking mode exit condition is satisfied, control to exit the dynamic braking mode and enter the hydraulic braking mode with simultaneous front and rear wheel braking, specifically including: when the temperature rise of the vehicle's rear wheel brake disc is greater than the second preset temperature rise, control to execute the heat dissipation strategy for the rear brake disc and exit the dynamic braking mode to enter the hydraulic braking mode with simultaneous front and rear wheel braking; Controlling to execute the heat dissipation strategy for the rear brake disc includes: Requesting the air suspension controller to increase the ground clearance and increasing the air cooling method to dissipate heat from the front wheel brake disc and the rear wheel brake disc.

2. The vehicle braking control method under long downhill conditions according to claim 1, characterized in that, The dynamic braking mode exit condition is that the temperature rise of the vehicle's rear wheel brake disc is greater than the second preset temperature rise or the vehicle's braking required deceleration is greater than the preset deceleration.

3. A braking control system under long downhill conditions, characterized in that, It includes: The first acquisition module is used to obtain the vehicle's slope driving condition and the vehicle's braking energy recovery attribute; The second acquisition module is communicatively connected to the first acquisition module and is used to obtain the vehicle's operating condition when the vehicle does not have the braking energy recovery function or the vehicle has the braking energy recovery function but is in the energy recovery exit state; The rear wheel maximum braking force increase control module is used to increase the maximum braking force provided by the rear wheels; The first control module is communicatively connected to the second acquisition module and is used to control to cut off the hydraulic input of the front and rear wheels and enter the dynamic braking mode that preferentially brakes the rear wheels when the vehicle's braking required deceleration is less than the preset deceleration and the temperature rise of the rear wheel brake disc is less than the first preset temperature rise; The third acquisition module is used to obtain the condition that satisfies the dynamic braking mode exit condition; The second control module is communicatively connected to the third acquisition module and is used to control to exit the dynamic braking mode and enter the hydraulic braking mode with simultaneous front and rear wheel braking when the dynamic braking mode exit condition is satisfied; The second control module includes: The control unit is communicatively connected to the third acquisition module and is used to control to execute the heat dissipation strategy for the rear brake disc and exit the dynamic braking mode to enter the hydraulic braking mode with simultaneous front and rear wheel braking when the temperature rise of the vehicle's rear wheel brake disc is greater than the second preset temperature rise; Controlling to execute the heat dissipation strategy for the rear brake disc includes: Requesting the air suspension controller to increase the ground clearance and increasing the air cooling method to dissipate heat from the front wheel brake disc and the rear wheel brake disc.

Images