Hydraulic retarder braking method and related device based on multi-modal cooperative control

Abstract

This invention discloses a hydraulic retarder braking method and related device based on multi-modal collaborative control, belonging to the field of hydraulic retarder control technology. The method collects vehicle speed, system temperature, and actual torque during vehicle operation. Based on these parameters, it dynamically switches between stable air pressure control mode, stable torque control mode, and stable power control mode using a finite state machine. In stable air pressure control mode, a fixed air pressure value is output based on the actual torque. In stable torque control mode, the air pressure is dynamically adjusted using a pre-established air pressure-torque-speed relationship model. This invention can improve torque under low-speed conditions, reduce torque fluctuation rate at medium and high speeds, significantly reduce the temperature rise rate under continuous braking conditions, and significantly improve the overall braking energy utilization rate.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic retarder control technology, and relates to a hydraulic retarder braking method and related device based on multi-modal cooperative control. Background Technology

[0002] In the braking systems of heavy commercial vehicles and large engineering vehicles, traditional pneumatic hydraulic retarder serves as a key auxiliary braking device, playing an irreplaceable role in ensuring vehicle driving safety and braking stability under complex operating conditions.

[0003] When the vehicle triggers the retarder braking command, an external high-pressure air source is connected to the retarder control system as a power source. The high-pressure gas is delivered to the oil sump via an optimized pipeline network at a specific pressure gradient. The oil sump, serving as the storage and distribution unit for the working fluid, allows the fluid inside to flow through a flow channel system composed of a one-way valve and a throttle orifice plate under the static pressure of the high-pressure gas, entering the annular working chamber formed by the stator and rotor in a laminar or turbulent state. The fluid generates a reaction force on the rotating rotor, thus producing braking torque. The air pressure input from the high-pressure air source through the air pressure regulating valve is distributed according to the number of retarder braking positions, with a fixed air pressure value assigned to specific positions. The heat generated by the fluid during operation is carried away by the vehicle's cooling system.

[0004] This control method has the following drawbacks: 1. Braking torque is significantly affected by fluctuations in oil temperature and rotational speed, resulting in strong nonlinearity in the braking process; 2. A single pneumatic control mode cannot adapt to the braking power requirements under complex operating conditions, leading to low braking energy utilization; 3. Prolonged braking easily causes oil overheating, resulting in significant thermal fade; 4. The retarder torque performance is entirely dependent on product consistency and cannot be adaptively adjusted. Therefore, it is urgent to develop a new hydraulic retarder control method to solve the problems of non-closed-loop braking process, large braking fluctuations, and thermal management deficiencies in traditional hydraulic retarder control methods. Summary of the Invention

[0005] The purpose of this invention is to provide a hydraulic retarder braking method and related device based on multimodal cooperative control, so as to solve the technical problems of non-closed-loop braking process, large braking fluctuation and thermal management defects in the traditional hydraulic retarder control method in the prior art.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] In a first aspect, the present invention provides a hydraulic retarder braking method based on multimodal cooperative control, comprising the following steps:

[0008] During vehicle operation, vehicle speed, system temperature, and actual torque are collected.

[0009] Based on vehicle speed, system temperature, and actual torque, a finite state machine is used to dynamically switch between stable air pressure control mode, stable torque control mode, and stable power control mode.

[0010] In the stable air pressure control mode, a fixed air pressure value is output based on the actual torque;

[0011] In the stable torque control mode, the air pressure is dynamically adjusted by a pre-established air pressure-torque-speed relationship model;

[0012] In the stable power control mode, the required power value is calculated, and the air pressure is dynamically adjusted according to the required power value.

[0013] Furthermore, the control logic of the finite state machine is as follows:

[0014] When the vehicle speed is higher than the preset low speed threshold, it gradually transitions from the stable air pressure control mode to the stable torque control mode.

[0015] When the system temperature exceeds the preset temperature threshold, it will be forced to switch to stable power control mode and activate the cooling system.

[0016] When the torque deviation exceeds the preset deviation threshold, the calibration is recalculated based on the air pressure-torque-speed relationship model.

[0017] Furthermore, the step of outputting a fixed air pressure value based on the actual torque during the stable air pressure control mode specifically includes:

[0018] When the vehicle is traveling at low speed and the actual torque is less than the target torque, the system enters a stable air pressure control mode, fixing the output torque and the maximum air pressure P_max.

[0019] Furthermore, the step of dynamically adjusting the air pressure using a pre-established air pressure-torque-speed relationship model during the stable torque control mode specifically includes:

[0020] In the stable torque control mode, the air pressure value required to achieve the target torque is calculated using a pre-established air pressure-torque-speed relationship model. The specific calculation formula is as follows:

[0021]

[0022] In the formula, P T(A) Indicates the required air pressure value; P Tv This represents the reference air pressure value calculated based on the target torque; This indicates the torque-speed trend correction value; This indicates that the Kalman filter corrects the air pressure value in real time; Δ Indicates the temperature compensation value;

[0023] During braking, vehicle speed, system temperature and actual torque are continuously monitored. When vehicle speed or braking demand changes, the target torque and required air pressure value are recalculated.

[0024] When the temperature reaches the compensation value or the torque deviation ΔT touches the preset deviation threshold, the system is forced to enter the stable power control mode and add a temperature compensation value, while lowering the target torque and air pressure values.

[0025] Furthermore, the process of establishing the pressure-torque-speed relationship model is as follows:

[0026] Tests were conducted on batches of vehicles to obtain air pressure-torque-speed relationship data. Based on the measured data, an air pressure-torque-speed relationship model was constructed using the difference iteration method and mechanical characteristic formulas. The expression for the mechanical characteristic formulas is as follows:

[0027] Tq=K·ρ(t)·v 2 ·D 5

[0028] In the formula, Tq represents air pressure; K is a constant; ρ(t) is the temperature-compensated oil density; v is the velocity; and D is the characteristic dimension.

[0029] Furthermore, the step of calculating the required power value and dynamically adjusting the air pressure based on the required power value during the stable power control mode specifically includes:

[0030] In the stable power control mode, the required power value Pw at the real-time vehicle speed with the target torque is calculated based on the pre-established power model;

[0031] If the required power value Pw is less than the rated power value Pw_set, then the torque is controlled in the stable air pressure control mode.

[0032] If the required power value Pw is greater than the rated power value Pw_set, the air pressure output is adjusted to be less than the target torque value. At the same time, it is adjusted in real time according to the vehicle speed change so that the power during braking is close to the rated power value Pw_set. Meanwhile, the retarder temperature is monitored. When the temperature rises, the rated power value Pw_set is reduced according to the temperature compensation item and the set compensation coefficient.

[0033] Furthermore, the expression for the power model is:

[0034] Pw=η·T·v / 9550+ΔPw(Δt-Q)

[0035] In the formula, Pw represents the required power value; η is the efficiency coefficient; Q is the flow rate; v is the vehicle speed; and ΔPw(Δt-Q) represents the compensation power related to temperature trend and flow rate.

[0036] Secondly, the present invention provides a hydraulic retarder braking system based on multimodal cooperative control, comprising:

[0037] The data acquisition module is used to collect vehicle speed, system temperature, and actual torque during vehicle operation;

[0038] The mode switching module is used to dynamically switch between stable air pressure control mode, stable torque control mode and stable power control mode based on vehicle speed, system temperature and actual torque through a finite state machine.

[0039] The SPC module is used to output a fixed air pressure value based on the actual torque during stable air pressure control mode.

[0040] The STC module is used to dynamically adjust the air pressure by means of a pre-established air pressure-torque-speed relationship model during stable torque control mode.

[0041] The SPoC module is used to calculate the required power value in stable power control mode and dynamically adjust the air pressure according to the required power value.

[0042] Thirdly, the present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the hydraulic retarder braking method based on multimodal cooperative control as described above.

[0043] Fourthly, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the hydraulic retarder braking method based on multimodal cooperative control as described above.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] This invention discloses a hydraulic retarder braking method and related device based on multi-modal collaborative control. When the vehicle is in a low-speed condition and the actual torque is less than the target torque, the system quickly enters a stable air pressure control mode. Based on a pre-set air pressure value, the air pressure regulating valve can quickly and accurately control the vehicle's air supply, pumping the working oil into the working chamber. In the stable torque control mode, the air pressure value required to achieve the target torque is calculated through a pre-established air pressure-torque-speed relationship model. In the stable power control mode, the power output is dynamically adjusted according to the real-time vehicle speed and torque demand, ensuring that the power during braking remains within a reasonable range close to the calibrated value. This invention enables flexible switching between stable air pressure control mode, stable torque control mode, and stable power control mode. It increases torque by 25% in low-speed conditions (reaching 2500 N·m at 30 km / h), reduces torque fluctuation rate at medium and high speeds by ≤±5%, decreases the temperature rise rate during continuous braking, and significantly improves the overall braking energy utilization rate. Attached Figure Description

[0046] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a flowchart of the method of the present invention;

[0048] Figure 2 This is a schematic diagram of the system of the present invention;

[0049] Figure 3 The torque curves of the retarder with three modes of coordinated control are shown in the embodiments of the present invention.

[0050] Figure 4 This is a schematic diagram of the computer device structure of the present invention.

[0051] Among them: 1. SPC mode, 2. STC mode, 3. SPoC mode, 4. Maximum mechanical characteristic curve, 5. Pw_set1 torque curve, 6. Pw_set2 torque curve, 7. Temperature compensation. Detailed Implementation

[0052] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0053] The following detailed description is exemplary and intended to provide further detailed explanation of the invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used in this invention is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention.

[0054] See Figure 1 This invention discloses a hydraulic retarder braking method based on multimodal cooperative control, comprising the following steps:

[0055] S1 collects vehicle speed, system temperature, and actual torque during vehicle operation;

[0056] S2, based on vehicle speed, system temperature and actual torque, dynamically switches between stable air pressure control mode, stable torque control mode and stable power control mode through a finite state machine;

[0057] The control logic of the finite state machine (FSM) is as follows:

[0058] When the vehicle speed is higher than the preset low speed threshold, it gradually transitions from the stable air pressure control mode to the stable torque control mode.

[0059] When the system temperature exceeds the preset temperature threshold, it will be forced to switch to stable power control mode and activate the cooling system.

[0060] When the torque deviation exceeds the preset deviation threshold, the calibration is recalculated based on the air pressure-torque-speed relationship model.

[0061] S3, in the stable air pressure control mode, outputs a fixed air pressure value based on the actual torque;

[0062] When the vehicle is driving at low speed and the actual torque T is less than the target torque T(A), that is, the mechanical characteristics cannot reach the target torque, the system enters the stable air pressure control mode, the air pressure setpoint P0 = P_max, and the fixed output torque is associated with the maximum air pressure P_max.

[0063] Applicable scenarios: During the low-speed phase of normal braking requests, such as when the vehicle speed is ≤ the preset low-speed threshold (e.g., 30km / h), the braking request intensity A is relatively large, and the torque output is directly related to the maximum air pressure P_max (e.g., 500kPa), with the torque output being the maximum mechanical characteristic.

[0064] S4, in the stable torque control mode, dynamically adjusts the air pressure through a pre-established air pressure-torque-speed relationship model;

[0065] In the stable torque control mode, the air pressure value required to achieve the target torque is calculated using a pre-established air pressure-torque-speed relationship model. The specific calculation formula is as follows:

[0066]

[0067] In the formula, P T(a) Indicates the required air pressure value; P Tv This represents the reference air pressure value calculated based on the target torque; This indicates the torque-speed trend correction value; This indicates that the Kalman filter corrects the air pressure value in real time; Indicates the temperature compensation value;

[0068] During braking, vehicle speed, system temperature and actual torque are continuously monitored. When vehicle speed or braking demand changes, the target torque and required air pressure value are recalculated.

[0069] When the temperature reaches the compensation value or the torque deviation ΔT touches the preset deviation threshold, the system is forced to enter the stable power control mode and add a temperature compensation value, while lowering the target torque and air pressure values.

[0070] Applicable scenarios: Suitable for medium to high speed operating conditions requiring precise torque braking control (such as EBS activation or constant speed on ramps).

[0071] In a feasible embodiment of the present invention, the process of establishing the air pressure-torque-speed relationship model is as follows:

[0072] Tests were conducted on batches of vehicles to obtain air pressure-torque-speed relationship data. Based on the measured data, an air pressure-torque-speed relationship model was constructed using the difference iteration method and mechanical characteristic formulas. The expression for the mechanical characteristic formulas is as follows:

[0073] Tq=K·ρ(t)·v 2 ·D 5

[0074] In the formula, Tq represents air pressure; K is a constant; ρ(t) is the temperature-compensated oil density; v is the velocity; and D is the characteristic dimension.

[0075] S5 calculates the required power value during stable power control mode and dynamically adjusts the air pressure based on the required power value.

[0076] In the stable power control mode, the required power value Pw at the real-time vehicle speed and target torque is calculated based on a pre-established power model; the expression for the power model is:

[0077] Pw=η·T·v / 9550+ΔPw(Δt-Q)

[0078] In the formula, Pw represents the required power value; η is the efficiency coefficient; Q is the flow rate; v is the vehicle speed; and ΔPw(Δt-Q) represents the compensation power related to temperature trend and flow rate.

[0079] If the required power value Pw is less than the rated power value Pw_set, then the torque is controlled in the stable air pressure control mode.

[0080] If the required power value Pw is greater than the rated power value Pw_set, the air pressure output is adjusted to be less than the target torque value. At the same time, it is adjusted in real time according to the vehicle speed change so that the power during braking is close to the rated power value Pw_set. Meanwhile, the retarder temperature is monitored. When the temperature rises, the rated power value Pw_set is reduced according to the temperature compensation item and the set compensation coefficient.

[0081] Applicable scenarios: Energy management when driving on long downhill slopes at high speeds or when the vehicle's cooling system is inadequate.

[0082] See Figure 2 This invention discloses a hydraulic retarder braking system based on multimodal cooperative control, including a data acquisition module, a mode switching module, an SPC module, an STC module, and an SPoC module.

[0083] The system includes: a data acquisition module for collecting vehicle speed, system temperature, and actual torque during vehicle operation; a mode switching module for dynamically switching between stable air pressure control mode, stable torque control mode, and stable power control mode using a finite state machine based on vehicle speed, system temperature, and actual torque; an SPC module for outputting a fixed air pressure value based on actual torque during stable air pressure control mode; an STC module for dynamically adjusting air pressure using a pre-established air pressure-torque-speed relationship model during stable torque control mode; and an SPoC module for calculating the required power value and dynamically adjusting the air pressure based on the required power value during stable power control mode.

[0084] This invention addresses the problems of non-closed-loop braking, large braking fluctuations, and thermal management deficiencies inherent in traditional hydraulic retarder control methods. It is applicable to braking energy management in heavy vehicles such as commercial vehicles and construction machinery, achieving high torque braking at low speeds, stable torque braking at medium and high speeds, and preventing over-temperature alarms during high-speed or long-term braking, thus improving overall braking efficiency. Specifically, it proposes a three-modal collaborative control strategy that dynamically switches control modes through a vehicle speed (v) and temperature (t) dual-factor decision-making mechanism to achieve:

[0085] Low speed, high torque (e.g., 0-30km / h): Maximize mechanical characteristics by applying torque-correlated maximum air pressure control (SPC).

[0086] Medium-to-high speed constant torque (e.g., 30-80km / h): Stable torque control (STC) adjusts air pressure to achieve dynamic torque stability.

[0087] Full-condition power protection: Stable power control (SPoC), combined with temperature compensation coefficient to prevent the vehicle cooling system from overheating.

[0088] Example:

[0089] See Figure 3 This embodiment discloses a hydraulic retarder braking method based on multimodal cooperative control, and the specific implementation process is as follows:

[0090] 1. System Calibration: The retarder controller is programmed with a pneumatic pressure (P)-torque (T)-speed (v) relationship model. The SPoC (Static Power Coefficient) is calibrated according to the vehicle model, the temperature compensation coefficient is calibrated based on the operating environment, and other parameters are calibrated. Upon vehicle startup, the system performs a self-check on sensors, actuators, and other hardware to ensure they are functioning correctly.

[0091] 2. Operating Condition Judgment: The system collects information such as vehicle speed (v), engine speed, and brake pedal status in real time, and determines the vehicle's current operating condition based on this information. When the vehicle speed is below the set low-speed threshold (e.g., 25 km / h), it is determined to be a low-speed operating condition; when the vehicle speed is in the medium-high speed range (e.g., 40-100 km / h), it is determined to be a medium-high speed operating condition; when the vehicle speed is above the set high-speed threshold (e.g., 80 km / h), it is determined to be a high-speed operating condition.

[0092] 3. Stable Air Pressure (SPC) Control Mode Execution: When the system is determined to be operating at low speed, and the actual torque T < target torque T(A) according to the model, the system enters the stable air pressure control mode. Based on the preset air pressure value, the air supply to the vehicle is controlled via the air pressure regulating valve to pump the working oil into the working chamber. At this time, the torque performance depends on the mechanical characteristics of the retarder itself. If the actual torque T > target torque T(A), the control state switches to STC mode.

[0093] 4. Stable Torque Control (STC) Mode Execution: The user (driver or EBS) requests a target torque T(A). Based on the pre-established torque model, the air pressure value required to achieve the target torque T(A) is calculated in reverse. During braking, the system continuously monitors vehicle speed v, temperature t, and target torque T(A). When vehicle speed v or braking demand changes, the target torque and required air pressure value are recalculated. When the temperature reaches the compensation value or the trend ΔT touches the intervention point, the system is forced to enter SPoC mode and a temperature compensation value is added. The target torque and air pressure value are adjusted down in a timely manner to ensure that the retarder adjusts the torque in time and ensures that the continuous torque output is uninterrupted.

[0094] 5. Stable Power Control Mode Execution: When the vehicle is at a high speed (v), the system enters stable power control mode. First, the vehicle speed (v) is acquired in real-time. The user (driver or EBS) requests torque demand (T(A)). The required power value (Pw) at the real-time vehicle speed (v) is calculated using the formula. If it is lower than the rated power value (Pw_set), torque is controlled in STC mode. If the required power value (Pw) is greater than the rated power value (Pw_set), the system adjusts the air pressure output to be less than the required torque (T(A)) using a power algorithm and torque model. Simultaneously, adjustments are made in real-time according to changes in vehicle speed (v) to ensure the power output during braking is close to the rated value (Pw_set). The retarder temperature is also monitored. When the temperature rises, the rated power value is appropriately reduced based on the temperature compensation term and the set compensation coefficient. For example, when the coolant temperature rises to 100℃ or above 90℃ and increases by more than 5℃ within 1 second, the rated power value is adjusted to 95% of the original value based on the compensation coefficient, and the air pressure is readjusted to prevent the retarder from overheating and triggering an alarm or causing braking interruption. Throughout the control process, the system continuously adjusts the air pressure to keep the retarder's power output stable near the corrected power calibration value, ensuring the continuity, safety, and stability of the high-speed braking process.

[0095] 6. Mode Switching: A finite state machine (FSM) is developed to implement mode switching. During vehicle operation, signals such as real-time vehicle speed v, braking request intensity A (gear position), and system temperature t are identified. When the vehicle speed transitions from low to medium speed, approaching the trigger condition, SPC gradually transitions to STC, with a transition time ≤2s. If high-temperature protection is triggered during continuous braking (T≥100℃), the system is forcibly switched to SPoC mode and the cooling system is activated. When the vehicle decelerates from high speed to medium-high speed, the system switches from stable power control mode to stable torque control mode. During mode switching, the impact of temperature compensation is considered to maximize the system's braking efficiency. In STC and SPoC states, if the torque exceeds the tolerance (|ΔT|>5%), recalculation and calibration are performed based on the torque model. A fuzzy decision algorithm is activated when the braking intensity A changes abruptly.

[0096] In one embodiment of the present invention, a computer device is provided, comprising a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions from the computer storage medium to achieve a corresponding method flow or corresponding function. The processor described in this embodiment of the present invention can be used for the operation of a hydraulic retarder braking method based on multimodal cooperative control.

[0097] This invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, this storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the hydraulic retarder braking method based on multimodal cooperative control in the above embodiments.

[0098] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. 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. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0099] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0100] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0101] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A braking method for a hydraulic retarder based on multimodal cooperative control, characterized in that, Includes the following steps: During vehicle operation, vehicle speed, system temperature, and actual torque are collected. Based on vehicle speed, system temperature, and actual torque, a finite state machine is used to dynamically switch between stable air pressure control mode, stable torque control mode, and stable power control mode. In the stable air pressure control mode, a fixed air pressure value is output based on the actual torque; In the stable torque control mode, the air pressure is dynamically adjusted using a pre-established air pressure-torque-speed relationship model; specifically including: In the stable torque control mode, the air pressure value required to achieve the target torque is calculated using a pre-established air pressure-torque-speed relationship model. The specific calculation formula is as follows: = +D +D +D In the formula, Indicates the required air pressure value; This represents the reference air pressure value calculated based on the target torque; Δ Indicates the torque-speed trend correction value; Δ This indicates that the Kalman filter corrects the air pressure value in real time; Δ Indicates the temperature compensation value; During braking, vehicle speed, system temperature and actual torque are continuously monitored. When vehicle speed or braking demand changes, the target torque and required air pressure value are recalculated. When the temperature reaches the compensation value or the torque deviation ΔT touches the preset deviation threshold, the system is forced to enter the stable power control mode and the temperature compensation value is added, while the target torque and air pressure values ​​are lowered. In the stable power control mode, the required power value is calculated, and the air pressure is dynamically adjusted according to the required power value.

2. The hydraulic retarder braking method based on multi-modal cooperative control according to claim 1, characterized in that, The control logic of the finite state machine is as follows: When the vehicle speed is higher than the preset low speed threshold, it gradually transitions from the stable air pressure control mode to the stable torque control mode. When the system temperature exceeds the preset temperature threshold, it will be forced to switch to stable power control mode and activate the cooling system. When the torque deviation exceeds the preset deviation threshold, the calibration is recalculated based on the air pressure-torque-speed relationship model.

3. The hydraulic retarder braking method based on multi-modal cooperative control according to claim 1, characterized in that, The step of outputting a fixed air pressure value based on the actual torque during the stable air pressure control mode specifically includes: When the vehicle is traveling at low speeds and the actual torque is less than the target torque, the system enters a stable air pressure control mode, fixing the output torque in relation to the maximum air pressure. _ .

4. The hydraulic retarder braking method based on multi-modal cooperative control according to claim 1, characterized in that, The process of establishing the pressure-torque-speed relationship model is as follows: Tests were conducted on batches of vehicles to obtain air pressure-torque-speed relationship data. Based on the measured data, an air pressure-torque-speed relationship model was constructed using the difference iteration method and mechanical characteristic formulas. The expression for the mechanical characteristic formulas is as follows: Tq=K·ρ(t)·v²·D 5 In the formula, Tq represents air pressure; K is a constant; ρ(t) is the temperature-compensated oil density; v is the velocity; and D is the characteristic dimension.

5. The hydraulic retarder braking method based on multimodal cooperative control according to claim 1, characterized in that, The step of calculating the required power value and dynamically adjusting the air pressure according to the required power value during the stable power control mode specifically includes: In the stable power control mode, the required power value Pw at the real-time vehicle speed with the target torque is calculated based on the pre-established power model; If the required power value Pw is less than the rated power value Pw_set, then the torque is controlled in the stable air pressure control mode. If the required power value Pw is greater than the rated power value Pw_set, the air pressure output is adjusted to be less than the target torque value. At the same time, it is adjusted in real time according to the vehicle speed change so that the power during braking is close to the rated power value Pw_set. Meanwhile, the retarder temperature is monitored. When the temperature rises, the rated power value Pw_set is reduced according to the temperature compensation item and the set compensation coefficient.

6. The hydraulic retarder braking method based on multimodal cooperative control according to claim 5, characterized in that, The expression for the power model is: Pw=η·T·v / 9550 +ΔPw(Δt- Q) In the formula, Pw represents the required power value; η is the efficiency coefficient; Q is the flow rate; v is the vehicle speed; and ΔPw(Δt-Q) represents the compensation power related to temperature trend and flow rate.

7. A hydraulic retarder braking system based on multimodal cooperative control, characterized in that, include: The data acquisition module is used to collect vehicle speed, system temperature, and actual torque during vehicle operation; The mode switching module is used to dynamically switch between stable air pressure control mode, stable torque control mode and stable power control mode based on vehicle speed, system temperature and actual torque through a finite state machine. The SPC module is used to output a fixed air pressure value based on the actual torque during stable air pressure control mode. The STC module is used to dynamically adjust the air pressure in stable torque control mode by using a pre-established air pressure-torque-speed relationship model; specifically, it includes: In the stable torque control mode, the air pressure value required to achieve the target torque is calculated using a pre-established air pressure-torque-speed relationship model. The specific calculation formula is as follows: = +D +D +D In the formula, Indicates the required air pressure value; This represents the reference air pressure value calculated based on the target torque; Δ Indicates the torque-speed trend correction value; Δ This indicates that the Kalman filter corrects the air pressure value in real time; Δ Indicates the temperature compensation value; During braking, vehicle speed, system temperature and actual torque are continuously monitored. When vehicle speed or braking demand changes, the target torque and required air pressure value are recalculated. When the temperature reaches the compensation value or the torque deviation ΔT touches the preset deviation threshold, the system is forced to enter the stable power control mode and the temperature compensation value is added, while the target torque and air pressure values ​​are lowered. The SPoC module is used to calculate the required power value in stable power control mode and dynamically adjust the air pressure according to the required power value.

8. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the hydraulic retarder braking method based on multimodal cooperative control as described in any one of claims 1-6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the hydraulic retarder braking method based on multimodal cooperative control as described in any one of claims 1-6.

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