A braking optimization method and system for hydrostatically driven tracked vehicles

Abstract

The present invention proposes a method and system for optimizing braking of a hydrostatically driven tracked vehicle, comprising: identifying the driver's intention; identifying the braking situation classification of the hydrostatically driven tracked vehicle; selecting a corresponding preset braking method to brake the vehicle based on the driver's intention identification result and the braking situation classification result; distributing the braking force based on the corresponding preset braking method; braking the hydrostatically driven tracked vehicle based on the distributed braking force and identifying the operation of the accumulator; determining the actual braking deceleration of the vehicle based on the actual braking force applied to the hydrostatically driven tracked vehicle during braking; and re-identifying the braking situation classification of the hydrostatically driven tracked vehicle based on the actual braking deceleration of the vehicle, thereby completing the braking optimization of the hydrostatically driven tracked vehicle. The present invention can reasonably match hydraulic braking and mechanical braking, provide a braking control idea and a braking control strategy, and can improve the energy recovery efficiency of the system as well as its reliability and service life.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydraulic transmission, and in particular relates to a braking optimization method and system for a hydrostatically driven tracked vehicle. Background Art

[0002] In vehicle transmission systems, hydrostatic drive offers a range of advantages over traditional mechanical transmissions, including stepless speed regulation, low-speed stability, low shift shock and vibration, excellent maneuverability, reliability, and long life. It is widely used in engineering vehicles and agricultural machinery. Currently, hydrostatically driven tracked vehicles mostly utilize a dual-pump, motor-independent drive system. Engine power is transmitted via a speed increaser to two variable displacement pumps, which independently drive two variable displacement motors. This drive is then driven by a side transmission, with electro-hydraulic servo valves controlling the displacement of the pumps and motors, enabling both straight-line travel and steering. Patent ZL201310703782.0 describes a dual-sided hydrostatic coupled drive system that uses a power coupling device to combine and divide power from the two hydraulic systems. Patent ZL201110145318.5 describes an integrated, comprehensive hydrostatic drive continuously variable transmission mechanism for high-speed tracked vehicles, combining both straight-line speed change and steering functions to enable integrated lifting. The paper "Research on the Application Characteristics of Accumulators in Tracked Vehicle Hydrostatic Drive Systems" analyzes the characteristics of accumulators in hydraulic drive systems for absorbing pressure shocks, recovering energy, and reusing it. The paper "Research on Energy Recovery Technology in Tracked Vehicle Hydrostatic Drive Systems" studies the energy recovery effect of accumulators under different operating conditions and the dynamic response relationship between oil pressure and flow. However, hydrostatic drive systems utilize both hydraulic and mechanical braking during braking. These studies focus solely on the energy recovery effect and feasibility of accumulators, without addressing how to combine hydraulic and mechanical braking to improve the system's energy recovery efficiency, reliability, and service life. Summary of the Invention

[0003] The purpose of the present invention is to propose a braking optimization method and system for a hydrostatically driven tracked vehicle. Based on the working characteristics of the hydrostatic drive system of the tracked vehicle, and according to different working conditions and vehicle speed characteristics, the method rationally matches hydraulic braking and mechanical braking, and provides braking control ideas and braking control strategies, which can not only improve the energy recovery efficiency of the system, but also enhance reliability and service life.

[0004] To achieve the above object, the present invention provides a method for optimizing braking of a hydrostatically driven tracked vehicle, comprising:

[0005] Driver intention recognition based on the relationship between the preset brake pedal operating range and vehicle deceleration;

[0006] Identify the braking condition classification of hydrostatically driven tracked vehicles;

[0007] Based on the driver intention recognition result and the braking situation classification result, a corresponding preset braking mode is selected to brake the hydrostatic drive tracked vehicle;

[0008] Distributing the braking force based on the corresponding preset braking mode;

[0009] Braking a hydrostatically driven tracked vehicle based on the distributed braking force and performing accumulator operation identification;

[0010] Determine the actual braking deceleration of the vehicle based on the actual braking force applied to the vehicle during braking of the hydrostatically driven tracked vehicle;

[0011] Based on the actual braking deceleration of the vehicle, the braking condition classification of the hydrostatic drive tracked vehicle is re-identified, and the braking optimization of the hydrostatic drive tracked vehicle is completed.

[0012] Optionally, the method for presetting the relationship between the brake pedal operating range and the vehicle deceleration includes:

[0013] Define the operating range of the brake pedal as 0≤β≤β max When the brake pedal travel is 0≤β≤β0, it is idle and the vehicle deceleration is 0; when the brake pedal angle is β0≤β≤β max There is a linear relationship between the brake pedal angular displacement and the average speed of the driving wheels on both sides; when β>β max When the vehicle deceleration is a max ;

[0014] The preset relationship between the brake pedal operating range and the vehicle deceleration is:

[0015]

[0016] Among them, a is the braking deceleration, a max is the maximum braking deceleration, β is the current brake pedal angular displacement, β max is the maximum angular displacement of the brake pedal, and β0 is the angular displacement of the brake pedal free travel.

[0017] Optionally, the braking condition classification of the hydrostatically driven tracked vehicle includes:

[0018] Set 50km / h as the sign that the vehicle reaches the high-speed stage; set 10km / h as the dividing point between the medium and low-speed stages; set a=4m / s 2 As a sign to distinguish emergency braking from non-emergency braking; where a is the braking deceleration.

[0019] Optionally, the preset braking mode includes:

[0020] When the vehicle is at high speed, mechanical braking is the main method, supplemented by hydraulic braking;

[0021] When the vehicle is at medium or low speed, hydraulic braking is the main method, supplemented by mechanical braking;

[0022] When the vehicle is in emergency braking, the hydraulic brake is used to absorb the pressure shock, and the mechanical brake is used as an auxiliary brake;

[0023] When the vehicle is in non-emergency braking, the vehicle speed mode is used as the braking method.

[0024] Optionally, the braking force distribution method is:

[0025]

[0026] Among them, T z 、T m and T h are the total braking torque, mechanical braking torque and energy regeneration braking torque respectively, and μ is the braking force distribution coefficient.

[0027] Optionally, performing accumulator operation identification includes:

[0028] At the initial stage of vehicle braking, the real-time charging pressure p of the hydraulic accumulator is detected. a , determine whether the hydraulic regenerative braking is working or not, if p a <p hmax And p a <p h , the hydraulic regenerative braking works; otherwise, only the hydraulic motor braking works, p hmax and p h They are the maximum rated oil pressure and real-time oil pressure at the high-pressure end of the pump motor oil circuit respectively.

[0029] Optionally, the hydrostatically driven tracked vehicle braking optimization method further includes:

[0030] According to the engine speed n fed back in each sampling period s and high pressure side system pressure p h , and real-time vehicle speed v a To determine whether the target vehicle speed v d Make adjustments; if the engine speed n s There is a speed greater than the rated speed n e The trend or system pressure p h The maximum set pressure p is exceeded hmax If the vehicle deceleration rate is reduced, the vehicle deceleration rate needs to be reduced.

[0031] This embodiment also provides a hydrostatic drive tracked vehicle braking optimization system, the system comprising: a deceleration solving module, a braking condition identification module, a braking mode evaluation module, a braking force distribution module, an accumulator operation identification module, a braking parameter solving module, a system protection module, and a data acquisition and storage module;

[0032] The deceleration solving module is used to collect the change in the driver's brake pedal stroke and convert the change in stroke into the vehicle's deceleration;

[0033] The braking condition recognition module is used to collect the deceleration and speed characteristics of the vehicle, evaluate the vehicle speed mode and braking mode, and input them into the braking mode evaluation module;

[0034] The braking mode evaluation module is used to match the braking mode according to the vehicle speed mode and the braking mode; wherein the emergency braking mode has the highest level of braking mode matching;

[0035] The braking force distribution module is used to distribute the braking force to the hydraulic brake and the mechanical brake according to the matched braking mode;

[0036] The accumulator working identification module is used to detect the real-time charging pressure p of the hydraulic accumulator. a , determine whether the hydraulic regenerative braking is working;

[0037] The braking parameter solving module is used to import the braking mode and braking force into the vehicle dynamics model, solve the actual braking deceleration of the vehicle, and finally feed the actual braking deceleration back to the braking condition identification module;

[0038] The system protection module is used to find the engine speed n s There is a speed greater than the rated speed n e The trend or system pressure p h There is a tendency to exceed the maximum set pressure p hmax When the system alarm prompts that the deceleration is too large;

[0039] The data acquisition and storage module is used to collect time-varying data during vehicle braking, including vehicle speed v a Changes in hydraulic regenerative braking torque T h and mechanical braking torque T m Changes in system circuit pressure p h With the hydraulic accumulator pressure p a The changes in , the changes in braking deceleration a, the changes in driving distance s and the changes in energy recovery rate η.

[0040] The present invention has the following beneficial effects:

[0041] The present invention proposes a braking optimization method and system for a hydrostatically driven tracked vehicle. Based on the working characteristics of the hydrostatic drive system of the tracked vehicle, evaluation criteria for the vehicle speed mode and the braking mode are given. Based on this, the braking mode of the hydrostatic drive system is set, and the opening timing of the hydraulic brake and the mechanical brake is adjusted; then, through braking force distribution, accumulator oil charging and discharging control, vehicle dynamics model solution, etc., the hydraulic brake and the mechanical brake are reasonably matched, and a braking process protection function is set, which can not only improve the energy recovery efficiency of the system, but also enhance the reliability and service life of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0043] Figure 1 A schematic diagram of the principle of a hydrostatic drive system according to an embodiment of the present invention;

[0044] Figure 2 This is a schematic flow chart of a braking optimization method for a hydrostatically driven tracked vehicle according to an embodiment of the present invention;

[0045] Figure 3 A schematic diagram of the braking method, process and control strategy of the quiet night drive device according to an embodiment of the present invention;

[0046] Figure 4 This is a schematic structural diagram of a braking optimization system for a hydrostatically driven tracked vehicle according to an embodiment of the present invention;

[0047] Figure 5 Schematic diagram of vehicle data changes according to an embodiment of the present invention. DETAILED DESCRIPTION

[0048] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0050] like Figure 1As shown in the figure, a hydrostatic tracked vehicle consists of an engine, a speed increasing gearbox, two variable displacement pumps, an accumulator, a variable displacement motor, a side transmission, a mechanical brake, and a drive wheel. The speed increasing gearbox transmits engine power to the variable displacement pumps on both sides, which in turn drive the variable displacement motors. The output of the variable displacement motors is connected to the drive wheels via the side transmissions, propelling the vehicle. The accumulator, serving as an energy storage unit, is connected between the variable displacement pumps and the variable displacement motors. The control unit controls the opening and closing of a switching valve group to recover and release braking energy. The mechanical brake is installed between the side transmissions and the drive wheels.

[0051] like Figure 2 As shown, this embodiment proposes a braking optimization method for a hydrostatically driven tracked vehicle, comprising:

[0052] Driver intention recognition based on the relationship between the preset brake pedal operating range and vehicle deceleration;

[0053] Identify the braking condition classification of hydrostatically driven tracked vehicles;

[0054] Based on the driver intention recognition result and the braking situation classification result, a corresponding preset braking mode is selected to brake the hydrostatic drive tracked vehicle;

[0055] Distribute braking force based on the corresponding preset braking mode;

[0056] Braking the hydrostatically driven tracked vehicle based on the allocated braking force and identifying the operation of the accumulator; determining the subsequent operation mode of the accumulator and determining whether to activate the accumulator;

[0057] Determine the actual braking deceleration of the vehicle based on the actual braking force applied to the vehicle during braking of the hydrostatically driven tracked vehicle;

[0058] Based on the actual braking deceleration of the vehicle, the braking condition classification of the hydrostatic drive tracked vehicle is re-identified, and the braking optimization of the hydrostatic drive tracked vehicle is completed.

[0059] After classification, the braking method is continuously determined, transitioning from high speed to medium speed, then to low speed, and finally braking is completed. Different speed stages have different braking methods and need to be switched.

[0060] Specifically, in the present embodiment, in the driver intention recognition, the method of presetting the relationship between the brake pedal operating range and the vehicle deceleration includes: converting the change in the driver's brake pedal stroke into the vehicle deceleration. The brake pedal operating range is defined as 0≤β≤β max When the brake pedal travel is 0≤β≤β0, it is idle and the vehicle deceleration is 0; when the brake pedal angle is β0≤β≤β max There is a linear relationship between the brake pedal angular displacement and the average speed of the driving wheels on both sides; when β>βmax When the vehicle deceleration is a max .

[0061] The relationship between the preset brake pedal operating range and vehicle deceleration is:

[0062]

[0063] Among them, a is the braking deceleration, a max is the maximum braking deceleration, β is the current brake pedal angular displacement, β max is the maximum angular displacement of the brake pedal, and β0 is the angular displacement of the brake pedal free travel.

[0064] Specifically, in this embodiment, the braking situation is classified as follows: for high-speed tracked vehicles, 50 km / h is set as the sign that the vehicle reaches the high-speed stage, and 10 km / h is the dividing point between the vehicle's medium and low speeds. 2 As a sign to distinguish emergency braking from non-emergency braking.

[0065] Specifically, in this embodiment, the braking modes are classified as follows: wherein, hydraulic braking includes: motor braking or hydraulic regenerative braking (accumulator and motor working simultaneously);

[0066] ① When the vehicle is at high speed, the pressure in the hydraulic system working circuit is very high. This is generally the initial stage of braking. In order to ensure that the vehicle can normally complete the high-speed braking requirements, mechanical braking is mainly used, supplemented by hydraulic braking.

[0067] ② During the medium and low speed stages of vehicle braking, protect the mechanical brakes, with hydraulic braking as the main method and mechanical braking as the auxiliary method.

[0068] ③ During emergency braking, the instantaneous pressure shock in the system circuit is very large. In order to ensure the safety and reliability of vehicle braking, hydraulic braking is used to absorb the pressure shock, and mechanical braking is used as an auxiliary braking.

[0069] ④ When slow braking, use the vehicle speed mode to accurately determine the braking method.

[0070] Specifically, in this embodiment, the braking force distribution is: let T z 、T m and T h are the total braking torque, mechanical braking torque and energy regeneration braking torque respectively, and the braking force distribution coefficient is μ, μ∈(0,1), then

[0071]

[0072] Specifically, in this embodiment, the accumulator operation identification is: at the initial stage of vehicle braking, the real-time charging pressure p of the hydraulic accumulator is detected. a, determine whether the hydraulic regenerative braking is working or not, if p a <p hmax And p a <p h , the hydraulic regenerative braking works; otherwise, only the hydraulic motor braking works, p hmax and p h They are the maximum rated oil pressure and real-time oil pressure at the high-pressure end of the pump motor oil circuit respectively.

[0073] The braking method, process and control strategy of the quiet night drive device are as follows: Figure 3 As shown;

[0074] Specifically, in this embodiment, the braking parameters are solved by substituting the actual braking force on the vehicle into the vehicle dynamics model to determine the actual braking deceleration of the vehicle, and feeding the real-time braking deceleration back to the braking condition classification step.

[0075] Specifically, in this embodiment, the braking process protection: according to the engine speed n fed back in each sampling period, s and high pressure side system pressure p h , and real-time vehicle speed v a To determine whether the target vehicle speed v d That is, the motor target speed is adjusted. If the engine speed n s There is a speed greater than the rated speed n e The trend or system pressure p h There is a tendency to exceed the maximum set pressure p hmax , indicating that the vehicle is decelerating too quickly, and the vehicle's deceleration rate needs to be reduced.

[0076] like Figure 4 As shown, this embodiment also proposes a hydrostatic drive tracked vehicle braking optimization system, including:

[0077] Deceleration calculation module: collects the change in the driver's brake pedal stroke and converts it into the vehicle's deceleration;

[0078] Braking situation recognition module: collects the vehicle's deceleration and speed characteristics, evaluates the vehicle's speed mode (high speed, medium speed, low speed), braking mode (emergency braking, slow braking), and inputs them into the braking mode evaluation module;

[0079] Braking mode evaluation module: performs braking mode matching based on the vehicle speed mode and braking mode obtained in the braking situation identification module; in the braking mode evaluation module, the emergency braking mode has the highest level of braking mode matching.

[0080] Braking force distribution module: distributes braking force to hydraulic brakes and mechanical brakes according to the matching braking mode.

[0081] Accumulator working identification module: by detecting the real-time charging pressure p of the hydraulic accumulator a , determine whether the hydraulic regenerative braking is working or not.

[0082] Braking parameter solution module: imports the braking mode and braking force into the vehicle dynamics model, solves the actual braking deceleration of the vehicle, and finally feeds the actual braking deceleration back to the braking situation identification module.

[0083] System protection module: If the engine speed n s There is a speed greater than the rated speed n e The trend or system pressure p h There is a tendency to exceed the maximum set pressure p hmax , the system alarm prompts that the deceleration is too large.

[0084] Data acquisition and storage module: collects time-varying data during vehicle braking, including vehicle speed v a Changes in hydraulic regenerative braking torque T h and mechanical braking torque T m Changes in system circuit pressure p h With the hydraulic accumulator pressure p a The changes in , the changes in braking deceleration a, the changes in driving distance s and the changes in energy recovery rate η.

[0085] The following uses specific data to illustrate the implementation effect of this embodiment:

[0086] A 20L accumulator is selected, the initial charging pressure is 16MPa, and the maximum pressure limit of the hydraulic system is p hmax The initial braking speed is 32 km / h, and the vehicle's road resistance coefficient is 0.05, the adhesion coefficient is 0.68, and the initial braking deceleration is 2.5 m / s. 2 .

[0087] 1. Deceleration solution module: At the 49th second, the driver begins to retract the accelerator pedal, and the accelerator pedal travel ratio reaches zero 1 second later; at the 50th second, the driver presses the brake pedal.

[0088] 2. Braking situation identification module: The initial braking speed is 32km / h, which belongs to the medium speed mode and slow braking mode.

[0089] 3. Braking mode evaluation module: hydraulic braking is the main method, supplemented by mechanical braking.

[0090] 4. Braking force distribution module: distributes braking force according to the braking force distribution rules.

[0091] 5. Accumulator working identification module: The hydraulic system circuit pressure is only 12.2MPa, which does not reach the initial pressure value of the accumulator. The hydraulic braking is motor braking, and the accumulator does not recover energy.

[0092] 6. Braking Parameter Calculation Module: During the initial braking phase, the sudden increase in braking deceleration causes a significant oil pressure surge in the pump-motor circuit, exceeding the accumulator's initial charge pressure of 16 MPa. At this point, the accumulator's on-off valve receives a control signal and opens, absorbing the system pressure surge and storing it. As braking deceleration increases, the operating pressure in the pump-motor circuit rises rapidly, causing the hydraulic accumulator's control valve to open, recovering braking energy. The system's energy recovery rate is 10.1%.

[0093] 7. System protection module: The engine speed does not appear during the entire braking process s Greater than rated speed n e The trend or system pressure p h Exceeding the maximum set pressure p hmax trend.

[0094] 8. Data acquisition and storage module: such as Figure 5 As shown, the vehicle speed v is given a Changes in hydraulic regenerative braking torque T h and mechanical braking torque T m Changes in system circuit pressure p h With the hydraulic accumulator pressure p a The changes in , the changes in braking deceleration a, the changes in driving distance s and the changes in energy recovery rate η.

[0095] This embodiment proposes a braking optimization method and system for a hydrostatically driven tracked vehicle. Based on the working characteristics of the hydrostatic drive system of the tracked vehicle, evaluation criteria for vehicle speed mode and braking mode are given. Based on this, the braking mode of the hydrostatic drive system is set, and the activation timing of the hydraulic brake and the mechanical brake is adjusted. Then, through braking force distribution, accumulator oil charging and discharging control, and vehicle dynamics model solution, the hydraulic brake and the mechanical brake are reasonably matched, and a braking process protection function is set, which can not only improve the energy recovery efficiency of the system, but also enhance the reliability and service life of the device.

[0096] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for optimizing braking of a hydrostatically driven tracked vehicle, characterized in that: include: Driver intention recognition based on the relationship between the preset brake pedal operating range and vehicle deceleration; Identify the braking condition classification of hydrostatically driven tracked vehicles; Based on the driver intention recognition result and the braking situation classification result, a corresponding preset braking mode is selected to brake the hydrostatic drive tracked vehicle; Distributing the braking force based on the corresponding preset braking mode; Braking a hydrostatically driven tracked vehicle based on the distributed braking force and performing accumulator operation identification; The accumulator working identification includes: at the initial stage of vehicle braking, by detecting the real-time charging pressure p of the hydraulic accumulator a , determine whether the hydraulic regenerative braking is working or not, if p a <p hmax And p a <p h , the hydraulic regenerative braking works; otherwise, only the hydraulic motor braking works, p hmax and p h They are the maximum rated oil pressure and real-time oil pressure at the high-pressure end of the pump motor oil circuit; Determine the actual braking deceleration of the vehicle based on the actual braking force applied to the vehicle during braking of the hydrostatically driven tracked vehicle; Based on the actual braking deceleration of the vehicle, the braking situation classification of the hydrostatic drive tracked vehicle is re-identified and the braking optimization of the hydrostatic drive tracked vehicle is completed; The hydrostatic drive tracked vehicle braking optimization method also includes: According to the engine speed n fed back in each sampling period s and high pressure side system pressure p h , and real-time vehicle speed v a To determine whether the target vehicle speed v d Make adjustments; if the engine speed n s There is a speed greater than the rated speed n e The trend or system pressure p h The maximum set pressure p is exceeded hmax If the vehicle deceleration rate is reduced, the vehicle deceleration rate needs to be reduced.

2. The hydrostatically driven tracked vehicle braking optimization method according to claim 1, characterized in that: The method for presetting the relationship between the brake pedal operating range and the vehicle deceleration includes: Define the operating range of the brake pedal as 0≤β≤β max When the brake pedal travel is 0≤β≤β0, it is idle and the vehicle deceleration is 0; when the brake pedal angle is β0≤β≤β max There is a linear relationship between the brake pedal angular displacement and the average speed of the driving wheels on both sides; when β>β max When the vehicle deceleration is a max ; The preset relationship between the brake pedal operating range and the vehicle deceleration is: Among them, a is the braking deceleration, a max is the maximum braking deceleration, β is the current brake pedal angular displacement, β max is the maximum angular displacement of the brake pedal, and β0 is the angular displacement of the brake pedal free travel.

3. The hydrostatically driven tracked vehicle braking optimization method according to claim 1, characterized in that: The braking condition classification of the hydrostatically driven tracked vehicle includes: Set 50km / h as the sign that the vehicle reaches the high-speed stage; set 10km / h as the dividing point between the medium and low-speed stages; set a=4m / s 2 As a sign to distinguish emergency braking from non-emergency braking; where a is the braking deceleration.

4. The hydrostatically driven tracked vehicle braking optimization method according to claim 3, characterized in that: The preset braking mode includes: When the vehicle is at high speed, mechanical braking is the main method, supplemented by hydraulic braking; When the vehicle is at medium or low speed, hydraulic braking is the main method, supplemented by mechanical braking; When the vehicle is in emergency braking, the hydraulic brake is used to absorb the pressure shock, and the mechanical brake is used as an auxiliary brake; When the vehicle is in non-emergency braking, the vehicle speed mode is used as the braking method.

5. The hydrostatically driven tracked vehicle braking optimization method according to claim 1, characterized in that: The braking force distribution method is: Among them, T z 、T m and T h are the total braking torque, mechanical braking torque and energy regeneration braking torque respectively, and μ is the braking force distribution coefficient.

6. A hydrostatic drive tracked vehicle braking optimization system, characterized in that: A system for implementing the braking optimization method for a hydrostatically driven tracked vehicle according to any one of claims 1 to 5, comprising: a deceleration solving module, a braking condition identification module, a braking mode evaluation module, a braking force distribution module, an accumulator operation identification module, a braking parameter solving module, a system protection module, and a data acquisition and storage module; The deceleration solving module is used to collect the change in the driver's brake pedal stroke and convert the change in stroke into the vehicle's deceleration; The braking condition recognition module is used to collect the deceleration and speed characteristics of the vehicle, evaluate the vehicle speed mode and braking mode, and input them into the braking mode evaluation module; The braking mode evaluation module is used to match the braking mode according to the vehicle speed mode and the braking mode; wherein the emergency braking mode has the highest level of braking mode matching; The braking force distribution module is used to distribute the braking force to the hydraulic brake and the mechanical brake according to the matched braking mode; The accumulator working identification module is used to detect the real-time charging pressure p of the hydraulic accumulator. a , determine whether the hydraulic regenerative braking is working; The braking parameter solving module is used to import the braking mode and braking force into the vehicle dynamics model, solve the actual braking deceleration of the vehicle, and finally feed the actual braking deceleration back to the braking condition identification module; The system protection module is used to find the engine speed n s There is a speed greater than the rated speed n e The trend or system pressure p h There is a tendency to exceed the maximum set pressure p hmax When the system alarm prompts that the deceleration is too large; The data acquisition and storage module is used to collect time-varying data during vehicle braking, including vehicle speed v a Changes in hydraulic regenerative braking torque T h and mechanical braking torque T m Changes in system circuit pressure p h With the hydraulic accumulator pressure p a The changes in , the changes in braking deceleration a, the changes in driving distance s and the changes in energy recovery rate η.

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