Electronic hydraulic braking system and vehicle
By adopting the electronic stability control system and the distribution ratio control of the master cylinder module in the dual-electron hydraulic braking system, the control problem during parking is solved, and effective braking and energy savings are achieved.
Patent Information
- Application Number
- CN202510471383.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-15
- Publication Date
- 2025-05-30
AI Technical Summary
Based on the dual electronic hydraulic braking system (EHB), how to effectively control the parking time, especially in commercial vehicles with loads greater than 6 tons, the assistance capacity may be insufficient.
An electronic hydraulic braking system is adopted, including an electronic stability control system, an oil pot module, a first master cylinder module and a second master cylinder module. By obtaining the maximum hydraulic pressure at a static limit, and distributing the target braking output according to the distribution ratio of the master cylinder module, the target braking output is achieved.
Effective control during parking is achieved, energy waste of excessive hydraulic pressure is avoided, and good braking effect is ensured, especially in vehicles with large loads.
Smart Images
Figure CN120056946A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of braking systems, in particular to electric hydraulic braking systems and vehicles. Background Art
[0002] The electric hydraulic brake (EHB) system is developed on the basis of the traditional hydraulic brake. The operating mechanism replaces the traditional hydraulic brake pedal with an electronic brake pedal and eliminates the large-volume vacuum booster.
[0003] For commercial vehicles with a load greater than 6 tons, the boosting ability may be insufficient when using the existing electric hydraulic braking system.
[0004] The applicant proposed using a dual EHB system in other patents to address the possible insufficient boosting ability of a single EHB system.
[0005] Based on the dual EHB system, how to control during parking is the technical problem to be solved in this application. Summary of the Invention
[0006] The purpose of this application is to provide an electric hydraulic braking system and a vehicle to solve the technical problem of how to control during parking based on the dual EHB system.
[0007] To achieve the above purpose, the embodiments of this application have adopted the following technical solutions.
[0008] In a first aspect, the embodiments of this application provide an electric hydraulic braking system, including an electronic stability control system, an oil pot module, a first master cylinder module, and a second master cylinder module; both the first master cylinder module and the second master cylinder module have motors; the oil pot module is used to provide brake fluid for the first master cylinder module and the second master cylinder module; The oil pot module is respectively connected to the first master cylinder module and the second master cylinder module; Both the first master cylinder module and the second master cylinder module are connected to the electronic stability control system; the electronic stability control system is used to provide hydraulic pressure for the braking of the wheels; The control method of the electric hydraulic braking system includes: Obtain the static limit maximum hydraulic pressure, and allocate the target braking outputs of the first master cylinder module and the second master cylinder module according to the static limit maximum hydraulic pressure and the master cylinder module distribution ratio; the static limit maximum hydraulic pressure is the pre-calibrated hydraulic pressure that can keep the vehicle stationary; The electronic stability control system provides the static limit maximum hydraulic pressure for the braking of the wheels according to the braking outputs of the first master cylinder module and the second master cylinder module.
[0009] Optionally, the control method of the electronic hydraulic braking system further includes: When it is detected that the vehicle transitions from motion to static, if the target braking pressure indicated by the brake pedal is higher than the maximum hydraulic pressure of the static limit, the target braking outputs of the first master cylinder module and the second master cylinder module are reduced to the target braking outputs corresponding to the maximum hydraulic pressure of the static limit.
[0010] Optionally, the step of obtaining the maximum hydraulic pressure of the static limit includes: When receiving a brake pedal signal, determine whether the vehicle is static according to the vehicle speed; When it is determined that the vehicle is static, obtain the maximum hydraulic pressure of the static limit, and continue to maintain the hydraulic pressure of the first master cylinder module and the second master cylinder module after detecting that the brake pedal is released.
[0011] Optionally, the control method of the electronic hydraulic braking system further includes: After meeting any one of the following conditions, release the hydraulic pressure of the first master cylinder module and the second master cylinder module: It is detected that the electronic parking system is pulled up; it is detected that the accelerator pedal moves and the movement amount of the accelerator pedal exceeds the movement amount threshold; it is detected that the torque corresponding to the accelerator pedal is sufficient to make the vehicle drive away.
[0012] Optionally, the control method of the electronic hydraulic braking system further includes: When receiving a brake pedal signal and detecting that the vehicle speed drops to the parking vehicle speed threshold, make the target braking output of the second master cylinder module correspond to the target braking output of the maximum hydraulic pressure of the static limit, and gradually reduce the target braking output of the first master cylinder module.
[0013] Optionally, the control method of the electronic hydraulic braking system further includes: When receiving a brake pedal signal, detecting that the vehicle speed drops to the parking vehicle speed threshold, the target braking output of the second master cylinder module corresponds to the target braking output of the maximum hydraulic pressure of the static limit, and when it is detected that the braking demand increases according to the brake pedal signal, increase the target braking output of the second master cylinder module, and the second master cylinder module alone completes the pressure building.
[0014] Optionally, the control method of the electronic hydraulic braking system further includes: Adjust the distribution ratio of the master cylinder modules according to the temperature rise conditions of the first master cylinder module and the second master cylinder module.
[0015] Optionally, when the temperatures of the first master cylinder module and the second master cylinder module are lower than a preset control trigger threshold, the first master cylinder module and the second master cylinder module each bear half of the target braking output; When the temperature of the first master cylinder module or the second master cylinder module is higher than the control trigger threshold, the master cylinder module with a higher temperature bears a lower target braking output, and the master cylinder module with a lower temperature bears a higher target braking output.
[0016] Optionally, the step of obtaining the maximum hydraulic pressure of the static limit includes: Obtaining the maximum hydraulic pressure of the static limit according to the slope, or obtaining the maximum hydraulic pressure of the static limit according to the slope and the road surface friction coefficient.
[0017] In a second aspect, an embodiment of the present application provides a vehicle, which includes the electronic hydraulic braking system described in the first aspect.
[0018] Compared with the prior art, the present application has the following beneficial effects: The control method of the electronic hydraulic braking system provided by the embodiment of the present application can perform braking according to the maximum hydraulic pressure of the static limit, avoid energy waste caused by excessive hydraulic pressure, and ensure a good braking effect. Description of the Drawings
[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.
[0020] Figure 1 Schematic diagram of an electronic hydraulic braking system including an electronic stability control system, an oil pot module, a first master cylinder module, and a second master cylinder module provided by an embodiment of the present application; Figure 2 Schematic diagram of an electronic stability control system including a first oil circuit and a second oil circuit provided by an embodiment of the present application; Figure 3 For Figure 2 Schematic diagram of adding a first valve and a second valve on the basis; Figure 4 Schematic diagram of an implementation manner of a specific electronic stability control system 1 provided by an embodiment of the present application. Detailed Embodiments
[0021] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. The described embodiments are some, but not all, of the embodiments of this application. Components of the embodiments of this application described in the accompanying drawings here are usually arranged and designed in various different configurations.
[0022] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of this application that is claimed, but merely represents selected embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this application without creative efforts fall within the scope of protection of this application. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.
[0023] In the description of this application, it should be noted that: Relative terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations; "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.
[0024] Such as Figure 1 , an electronic hydraulic braking system includes an electronic stability control system (Electronic Stability Control, abbreviated as ESC), an oil pot module, a first master cylinder module, and a second master cylinder module; both the first master cylinder module and the second master cylinder module have motors.
[0025] Compared with the braking method of a traditional single master cylinder braking system, the beneficial effects of this electronic hydraulic braking system include: Since the electronic hydraulic braking system has at least two master cylinder modules, namely the first master cylinder module and the second master cylinder module, to provide hydraulic pressure, compared with the braking method of a traditional single master cylinder braking system, the ability of the electronic hydraulic braking system to assist in building pressure is significantly improved.
[0026] The control method of the electronic hydraulic braking system includes: Obtain the maximum hydraulic pressure for static limit; the maximum hydraulic pressure for static limit is pre-calibrated. When applying this hydraulic pressure to the wheel brake, the braking force generated by the brake at the maximum hydraulic pressure for static limit can more reliably stop the vehicle. In some cases, a hydraulic pressure less than the maximum hydraulic pressure for static limit can also satisfy vehicle stopping, but the maximum hydraulic pressure for static limit can more reliably stop the vehicle. The maximum hydraulic pressure for static limit can change with factors such as slope, and the maximum hydraulic pressure for static limit can be pre-calibrated according to factors such as slope. Allocate the target braking outputs of the first master cylinder module and the second master cylinder module according to the maximum hydraulic pressure for static limit and the distribution ratio of the master cylinder module; the first master cylinder module establishes hydraulic pressure according to the target braking output of the first master cylinder module and transmits hydraulic oil to the electronic stability control system; the second master cylinder module establishes hydraulic pressure according to the target braking output of the second master cylinder module and transmits hydraulic oil to the electronic stability control system; the target braking output of each master cylinder module has a corresponding relationship with the hydraulic pressure established by that master cylinder module. The electronic stability control system provides the maximum hydraulic pressure for static limit for the braking of the wheels according to the braking outputs of the first master cylinder module and the second master cylinder module.
[0027] For vehicles with a large load, during static pressure maintenance, due to the large demand for hydraulic pressure, the electronic stability control system can delay the parking time of the booster and ultimately the static pressure maintenance parking time by reasonably allocating and scheduling the braking forces of the front and rear axles and adopting the method of alternately maintaining static pressure on the front and rear axles.
[0028] One implementation method for reasonably allocating and scheduling the braking forces of the front and rear axles is as follows: for example, after the front axle maintains the maximum hydraulic pressure for static limit for a period of time, it switches to the rear axle to maintain the maximum hydraulic pressure for static limit. After the rear axle maintains the maximum hydraulic pressure for static limit for a period of time, it switches to the front axle to maintain the maximum hydraulic pressure for static limit, and so on in a cycle.
[0029] One implementation principle for reasonably allocating and scheduling the braking forces of the front and rear axles is as follows: the electronic stability control system can include a first oil circuit and a second oil circuit; the first oil circuit and the second oil circuit provide hydraulic pressure for the braking of different wheels, and the reasonable allocation and scheduling of the braking forces of the front and rear axles can be controlled by controlling the on or off of the valves in different oil circuits.
[0030] In order to connect the two oil circuits, the output of the first master cylinder module can include two paths, and the output of the second master cylinder module can include two paths, such as Figure 2 , there are the following connection relationships: The first path output of the first master cylinder module is connected to the first oil circuit; The second path output of the first master cylinder module is connected to the second oil circuit; The first path output of the second master cylinder module is connected to the first oil circuit; The second output path of the second master cylinder module is connected to the second oil path.
[0031] The first oil path and the second oil path include two implementation manners: one is that the first oil path and the second oil path respectively correspond to the front and rear axles, and the other is that the first oil path and the second oil path respectively correspond to the left and right wheels. In the implementation manner of the front and rear axles, front axle braking can be preferentially adopted, that is, more hydraulic flow and hydraulic pressure are allocated to the front axle, and the front axle braking force is more sufficient when driving forward. The braking effect of preferentially adopting front axle braking is better.
[0032] In some implementation manners, a valve can also be arranged between the output of the master cylinder module and the oil path of the electronic stability control system, so as to facilitate controlling the corresponding operation between different master cylinder modules and oil paths. For example Figure 3 , a first valve and a second valve are arranged: The first output path of the first master cylinder module is directly connected to the first oil path; The second output path of the first master cylinder module is connected to the second oil path through the first valve; The first output path of the second master cylinder module is connected to the first oil path through the second valve; The second output path of the second master cylinder module is directly connected to the second oil path.
[0033] Figure 4 An implementation manner of an electronic stability control system 1 with multiple valves is shown. In the figure, M represents a motor. The motor in the electronic stability control system 1 can drive 2 return pumps. The return pumps can return the oil to the oil pot module to release the brake. The oil pot module can include a large oil pot and two small oil pots; the large oil pot is respectively connected to the two small oil pots. The first small oil pot is connected to the first master cylinder module; the second small oil pot is connected to the second master cylinder module, which is convenient for the arrangement and oil use of the two master cylinder modules. In the figure, 1F and 2F represent the left and right wheels of the front axle, and 1R and 2R represent the left and right wheels of the rear axle. The left and right wheels of the front axle can be configured with brake pads having larger sizes and rougher surfaces, and the left and right wheels of the rear axle can be configured with smaller and slightly smoother brake pads. In this implementation manner, the front axle has stronger and more effective braking ability under the same hydraulic pressure, that is, preferentially using front axle braking is realized.
[0034] The control method of the electronic hydraulic braking system of the present application can be executed by a component with a control function in the electronic hydraulic braking system; the component with a control function can be a single controller or multiple controllers dispersed in each module; if there are multiple controllers, the multiple controllers have a function of communicating with each other.
[0035] This control method can be used not only in the scenario of parking, but also in the scenario of stopping from a driving state: when it is detected that the vehicle changes from a moving state to a static state, if the target braking pressure indicated by the brake pedal is higher than the maximum hydraulic pressure of the static limit, and at this time the target braking outputs of the first master cylinder module and the second master cylinder module are higher than the target braking outputs corresponding to the maximum hydraulic pressure of the static limit, then the target braking outputs of the first master cylinder module and the second master cylinder module are reduced to the target braking outputs corresponding to the maximum hydraulic pressure of the static limit. Thus, this control method can perform braking according to the maximum hydraulic pressure of the static limit, avoid the waste of energy caused by excessive hydraulic pressure, and ensure a good braking effect.
[0036] Regarding the judgment of whether the vehicle is in the scenario of stopping from a driving state, it can be determined according to factors such as the brake pedal signal and vehicle speed. For example, when there is a brake pedal signal, it is judged whether to park. That is, this control method can include: Receive the brake pedal signal and judge whether the vehicle is static; When it is determined that the vehicle is static, estimate the maximum hydraulic pressure of the static limit.
[0037] Regarding the method of estimating the maximum hydraulic pressure of the static limit, it can be based on various conditions, such as: It can be based on the road surface gradient, that is, obtain the maximum hydraulic pressure of the static limit according to the gradient; or obtain the maximum hydraulic pressure of the static limit according to the gradient and the road surface friction coefficient. For example, the road surface friction coefficient in rainy days is set to a smaller value.
[0038] After parking, the hydraulic pressure can be automatically maintained to keep the parking state. That is, the control method of the electronic hydraulic braking system further includes: When it is determined that the vehicle is static, after detecting that the brake pedal is released, continue to maintain the hydraulic pressure of the first master cylinder module and the second master cylinder module.
[0039] Regarding the conditions for stopping the automatic hydraulic pressure maintenance, it can be that after simultaneously satisfying the following conditions, the target braking output is set to zero, that is, release the hydraulic pressure of the first master cylinder module and the second master cylinder module: It is detected that the electronic parking system is pulled up; it is detected that the accelerator pedal moves and the movement amount of the accelerator pedal exceeds the movement amount threshold; it is detected that the torque corresponding to the accelerator pedal is sufficient to make the vehicle drive away.
[0040] The above step of detecting that the torque corresponding to the accelerator pedal is sufficient to make the vehicle drive away can include: Determine the torque sufficient to make the vehicle drive away according to the gradient, or according to the gradient and the road surface friction coefficient; Compare the torque corresponding to the accelerator pedal with the torque sufficient to make the vehicle drive away, so as to determine that the torque corresponding to the accelerator pedal is sufficient to make the vehicle drive away.
[0041] Regarding the situation of the above vehicle transitioning from motion to static, braking can also be implemented in combination with the hydraulic distribution changes of the first master cylinder module and the second master cylinder module. One implementation method is as follows: When a brake pedal signal is received and it is detected that the vehicle speed has decreased to the parking vehicle speed threshold, make the target braking output of the second master cylinder module correspond to the target braking output of the maximum hydraulic pressure at the static limit, and gradually reduce the target braking output of the first master cylinder module. In this implementation method, the braking force is reduced before the vehicle has completely stopped, that is, the braking force is reduced in advance, which is beneficial to comfort, and this braking force is sufficient to make the vehicle stop steadily. In addition, reducing the braking force in advance can avoid waste of braking force.
[0042] A special case of this implementation method is that the driver hopes to stop steadily as soon as possible. At this time, the braking force should not be reduced in advance. Then the following control logic can be set: When a brake pedal signal is received, it is detected that the vehicle speed has decreased to the parking vehicle speed threshold, the target braking output of the second master cylinder module corresponds to the target braking output of the maximum hydraulic pressure at the static limit, and it is detected that the braking demand increases according to the brake pedal signal, increase the target braking output of the second master cylinder module, and the second master cylinder module alone completes the pressure build-up. In this implementation method, since the second master cylinder module is already working while the first master cylinder module is in a state of reducing output, mobilize the second master cylinder module to complete the braking output without mobilizing the first master cylinder module, and the pressure build-up response is faster.
[0043] The hydraulic distribution changes of the above first master cylinder module and second master cylinder module can also be further combined with other factors, such as temperature: the distribution ratio of the master cylinder modules can be adjusted according to the temperature rise conditions of the first master cylinder module and the second master cylinder module.
[0044] There are various implementation methods for the hydraulic distribution of the first master cylinder module and the second master cylinder module in combination with temperature: (1) When the temperatures of the first master cylinder module and the second master cylinder module are lower than the preset regulation trigger threshold, the first master cylinder module and the second master cylinder module each bear half of the target braking output; When the temperature of the first master cylinder module or the second master cylinder module is higher than the regulation trigger threshold, make the master cylinder module with the higher temperature bear the lower target braking output, and the master cylinder module with the lower temperature bear the higher target braking output. The lower target braking output and the higher target braking output can be pre-calibrated ratios, such as 40% for the lower target braking output and 60% for the higher target braking output, or 30% for the lower target braking output and 70% for the higher target braking output.
[0045] (2) It is also possible not to set the above-mentioned control trigger threshold, and directly let the master cylinder module with a higher temperature bear a lower target braking output, and the master cylinder module with a lower temperature bear a higher target braking output.
[0046] Based on the above embodiments, the embodiments of the present application further provide a vehicle, which includes the above-mentioned electronic hydraulic braking system.
[0047] The device and system embodiments described above are merely illustrative. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative efforts.
[0048] The above is only a preferred specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. An electronic hydraulic brake system, characterized in that: It includes an electronic stability control system, an oil pot module, a first master cylinder module and a second master cylinder module; the first master cylinder module and the second master cylinder module both have motors; the oil pot module is used to provide brake fluid for the first master cylinder module and the second master cylinder module; The oil pot module is respectively connected to the first master cylinder module and the second master cylinder module; The first master cylinder module and the second master cylinder module are both connected to the electronic stability control system; The electronic stability control system is used to provide hydraulic pressure for braking of wheels; The control method of the electronic hydraulic brake system comprises: Acquire a maximum static limit hydraulic pressure, and distribute target brake outputs of the first master cylinder module and the second master cylinder module according to the maximum static limit hydraulic pressure and a master cylinder module distribution ratio; the maximum static limit hydraulic pressure is a pre-calibrated hydraulic pressure capable of making the vehicle stationary; The electronic stability control system provides the static limit maximum hydraulic pressure for braking the wheels according to the braking outputs of the first master cylinder module and the second master cylinder module.
2. The electronic hydraulic brake system according to claim 1, characterized in that: The control method of the electronic hydraulic brake system also includes: When it is detected that the vehicle switches from motion to static, if the target braking pressure indicated by the brake pedal is higher than the static limit maximum hydraulic pressure, the target braking outputs of the first master cylinder module and the second master cylinder module are reduced to the target braking outputs corresponding to the static limit maximum hydraulic pressure.
3. The electronic hydraulic brake system according to claim 1, characterized in that: The step of obtaining the maximum static limit hydraulic pressure comprises: When receiving the brake pedal signal, determine whether the vehicle is static based on the vehicle speed; When it is determined that the vehicle is static, the static limit maximum hydraulic pressure is obtained, and after it is detected that the brake pedal is released, the hydraulic pressure of the first master cylinder module and the second master cylinder module continues to be maintained.
4. The electronic hydraulic brake system according to claim 3, characterized in that: The control method of the electronic hydraulic brake system also includes: When any of the following conditions is met, the hydraulic pressure of the first master cylinder module and the second master cylinder module is released: It is detected that the electronic parking system is pulled up; it is detected that the accelerator pedal moves and the movement amount of the accelerator pedal exceeds the movement amount threshold; it is detected that the torque corresponding to the accelerator pedal is sufficient to drive the vehicle away.
5. The electronic hydraulic brake system according to claim 1, characterized in that: The control method of the electronic hydraulic brake system also includes: When a brake pedal signal is received and it is detected that the vehicle speed drops to the parking speed threshold, the target braking output of the second master cylinder module is made to correspond to the target braking output of the static limit maximum hydraulic pressure, and the target braking output of the first master cylinder module is gradually reduced.
6. The electronic hydraulic brake system according to claim 5, characterized in that: The control method of the electronic hydraulic brake system also includes: When a brake pedal signal is received, and it is detected that the vehicle speed is reduced to the parking speed threshold, and the target braking output of the second master cylinder module corresponds to the target braking output of the static limit maximum hydraulic pressure, and an increase in braking demand is detected according to the brake pedal signal, the target braking output of the second master cylinder module is increased, and the pressure build-up is completed by the second master cylinder module alone.
7. The electronic hydraulic brake system according to claim 1, characterized in that: The control method of the electronic hydraulic brake system also includes: The master cylinder module allocation ratio is adjusted according to the temperature rise of the first master cylinder module and the second master cylinder module.
8. The electronic hydraulic brake system according to claim 7, characterized in that: When the temperature of the first master cylinder module and the second master cylinder module is lower than a preset control trigger threshold, the first master cylinder module and the second master cylinder module each bear half of the target braking output; When the temperature of the first master cylinder module or the second master cylinder module is higher than the regulation triggering threshold, the master cylinder module with a higher temperature is made to bear a lower target braking output, and the master cylinder module with a lower temperature is made to bear a higher target braking output.
9. The electronic hydraulic brake system according to claim 1, characterized in that: The steps to obtain the maximum hydraulic pressure of the static limit include: The maximum static limit hydraulic pressure is obtained according to the slope, or according to the slope and the road friction coefficient.
10. A vehicle, characterized in that: The vehicle comprises the electronic hydraulic brake system according to any one of claims 1 to 9.