Load-sensitive large-flow intelligent hydraulic system applied to bulldozer

Abstract

The invention discloses a load-sensitive large-flow intelligent hydraulic system applied to a bulldozer, particularly relates to the technical field of engineering machinery hydraulics, and aims to overcome the defects of static setting of control parameters and weak anti-jamming capability of a common load-sensitive system by introducing dynamic proportional gain. Real-time adjustment is carried out by integrating swash plate deflection resistance, hydraulic oil temperature and working condition fluctuation coefficients, gain is increased when low temperature is high in viscosity, large in resistance or severe in working condition fluctuation, gain is reduced when high temperature is low in viscosity, small in resistance or stable in working condition, slow adjustment, clamping stagnation or overshoot is avoided, and the anti-interference capacity and control precision of a system under complex working conditions are improved.

Description

Technical Field

[0001] This invention relates to the field of hydraulic technology for construction machinery, and more specifically, to a load-sensitive, high-flow intelligent hydraulic system for bulldozers. Background Technology

[0002] As a core piece of engineering machinery in mining, road construction, and farmland improvement projects, bulldozers are characterized by severe load fluctuations, frequent compound actions of multiple actuators, and large temperature differences in the operating environment. This places extremely high demands on the precise flow matching capability of the hydraulic system.

[0003] Current hydraulic systems used in bulldozers have revealed numerous technical deficiencies during actual operation, making it difficult to meet the demands for efficient and stable operation under complex working conditions. Specific shortcomings are as follows: (1) Poor adaptability of flow rate and pressure output, resulting in serious energy waste. The output flow of a traditional fixed displacement pump system is a constant value and cannot be dynamically adjusted according to the actual action requirements of the actuator: when the actuator is operating alone or under light load, the excess flow needs to be released through the relief valve, resulting in a large amount of overflow energy loss; when multiple actuators are operating in combination or under heavy load, the fixed flow is difficult to meet the coordination requirements of each action, resulting in action jamming and low operating efficiency. (2) The control parameters are set statically, resulting in weak anti-interference ability. The core control parameters of ordinary load-sensitive systems are mostly preset fixed values, which cannot adapt to dynamic interference factors under complex working conditions: In low-temperature environments, the viscosity of hydraulic oil increases, the swashplate deflection resistance increases, and the fixed proportional gain will cause the pump displacement adjustment response to be slow, or even the swashplate to jam; In high-temperature environments, the viscosity of oil decreases, and the fixed proportional gain is prone to causing swashplate overshoot, resulting in flow and pressure fluctuations; When the working conditions fluctuate drastically, the fixed load-sensitive differential pressure is difficult to ensure the valve group flow is stable, which further reduces the system's anti-interference capability. The existing system does not quantitatively evaluate the degree of working condition fluctuations, the control strategy lacks targeted adjustments, and the control accuracy under complex working scenarios is significantly reduced; (3) Valve core wear and oil temperature effects are not effectively compensated, resulting in low flow control accuracy. After long-term operation, the valve core of the hydraulic system will wear due to friction, resulting in a reduction in the actual effective flow area of ​​the valve port. However, the existing system does not have a real-time monitoring and compensation mechanism for the wear of the valve core, and still calculates the flow rate based on the initial valve core state, which causes an increase in the deviation between the actual output flow rate of the valve port and the theoretical calculation value.

[0004] To address the aforementioned issues, a load-sensitive, high-flow intelligent hydraulic system for bulldozers has been developed. Summary of the Invention

[0005] To overcome the above-mentioned deficiencies of the prior art, embodiments of the present invention provide a load-sensitive, high-flow intelligent hydraulic system for bulldozers.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A load-sensitive, high-flow intelligent hydraulic system for bulldozers includes the following modules: Working condition sensing module: Real-time collection of working condition parameters of the bulldozer during operation, including load pressure and action speed of each actuator, engine speed, and hydraulic system oil temperature; Intelligent control module: Analyzes operating parameters using preset algorithms, calculates total demand flow, and generates variable pump displacement commands; Displacement adjustment module: It parses the displacement command of the intelligent variable pump and converts it into the target swashplate angle according to the pre-stored displacement-swashplate angle mapping table. After analyzing the swashplate deflection resistance, hydraulic oil temperature and operating condition fluctuation coefficient to determine the dynamic proportional gain, it uses the proportional adjustment algorithm to generate the adjustment current and sends it to the proportional electromagnet of the pump. After receiving the adjustment current, the proportional electromagnet outputs the corresponding thrust to drive the swashplate deflection. Valve assembly adjustment module: After the output thrust drives the swashplate to deflect, the flow correction coefficient is determined based on the load pressure of each actuator, the actual stroke of the valve core, the oil temperature, and the wear coefficient of the valve core. Based on the flow correction coefficient and the required flow of each actuator, the valve core stroke of the electro-hydraulic proportional load sensitive valve corresponding to each actuator is corrected.

[0007] Specifically, the logic for generating variable pump displacement instructions; For each actuator, its required flow rate is calculated from the action speed and effective working area; The total demand flow is obtained by summing the demand flows of each implementing agency. Based on the total demand flow, a variable pump displacement command is generated using a pre-stored variable pump displacement-flow mapping table. Calculate the target displacement of the variable pump based on the total demand flow and generate the variable pump displacement command.

[0008] Specifically, the generation logic for adjusting the current is generated using a proportional adjustment algorithm; The adjustment current is calculated using a proportional adjustment algorithm, expressed by the following formula: Adjust current ; in The target current is represented by the target swashplate angle converted using a pre-stored angle-current mapping rule; Indicates the angular deviation value; This indicates the dynamic proportional gain.

[0009] Specifically, the logic for calculating the angle deviation value; Mark the target swashplate angle as the output angle; The actual deflection angle of the swashplate is collected and marked as the execution angle. Then the angle deviation value = output angle - execution angle.

[0010] Specifically, the dynamic proportional gain calculation logic; It is obtained by comprehensively processing the swashplate deflection resistance, hydraulic oil temperature, and operating condition fluctuation coefficient; The hydraulic oil temperature and swashplate deflection resistance monitored in real time are standardized by using the set hydraulic oil working temperature range and swashplate deflection resistance range respectively. The standardized hydraulic oil temperature, swashplate deflection resistance, and operating condition fluctuation coefficient are comprehensively processed to obtain the interference degree index. The interference degree index is then converted into an additional coefficient and combined with a pre-determined basic proportional gain to obtain the dynamic proportional gain.

[0011] Specifically, the logic for obtaining the operating condition fluctuation coefficient; The changes in the system's peak load pressure and total demand flow rate per unit time are obtained and denoted as the pressure change coefficient and flow rate change coefficient, respectively. The pressure variation coefficient and the flow variation coefficient are weighted and fused to obtain the operating condition fluctuation coefficient.

[0012] Specifically, the correction logic for the valve core stroke; Obtain the load pressure of all actuators; Calculate valve flow rate using formula ; in This is the flow correction factor; The effective flow area of ​​the valve orifice; The pressure difference across the valve port; The density of the hydraulic oil; The valve flow rate calculated for each actuator is compared with the corresponding required flow rate. If the valve flow rate is lower than the required flow rate, the valve core stroke is increased; otherwise, the valve core stroke is decreased.

[0013] Specifically, the calculation logic for the effective flow area of ​​the valve orifice and the pressure difference across the valve orifice; The actual stroke of the valve core is w; the circumferential width of the valve port is w. For pump output pressure, Let be the load pressure of the i-th actuator.

[0014] Specifically, the calculation logic of the flow correction coefficient; Obtain the usage time of the valve core corresponding to each actuator, and convert it into wear amount using a pre-stored usage time-wear amount mapping table; Using formula Calculate the valve core wear coefficient ;in Let be the wear amount of the valve core corresponding to the i-th actuator. This is the maximum design stroke of the valve port; After weighted fusion of valve core wear coefficient and hydraulic oil temperature, valve core influence index is obtained. After converting valve core influence index into valve core adjustment coefficient, it is multiplied by preset reference flow coefficient to obtain flow correction coefficient.

[0015] The technical effects and advantages of this invention are as follows: (1) By collecting parameters in real time and accurately calculating the required flow of each actuator and superimposing them to obtain the total required flow, a suitable variable pump displacement command is generated to dynamically match the operation requirements. When a single action or light load is used, excess flow overflow loss is avoided. When multiple actuators perform compound actions or heavy loads, flow supply is guaranteed, the problem of action lag is solved, and the operation efficiency is improved. (2) To address the shortcomings of static setting of control parameters and weak anti-interference ability of ordinary load-sensitive systems, dynamic proportional gain is introduced to adjust in real time by comprehensively considering swashplate deflection resistance, hydraulic oil temperature and operating condition fluctuation coefficient. The gain is increased when the temperature is low and the viscosity is high, the resistance is large or the operating condition fluctuates violently, and the gain is decreased when the temperature is high and the viscosity is low, the resistance is small or the operating condition is stable, so as to avoid slow adjustment, jamming or overshoot, and improve the anti-interference ability and control accuracy of the system under complex operating conditions. (3) To address the problems of the existing system not compensating for valve core wear and oil temperature effects and low flow control accuracy, the wear amount is calculated by converting the valve core usage time, and the flow correction coefficient is calculated by combining the oil temperature. Based on the correction coefficient and load pressure, the valve port flow is accurately calculated. After comparing with the required flow, the valve core stroke is corrected to compensate for the reduction in flow area caused by valve core wear and the influence of oil temperature on oil fluidity, thereby reducing the deviation between the actual output flow and the theoretical value and significantly improving the flow control accuracy. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the load-sensitive, high-flow intelligent hydraulic system for bulldozers, based on the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] like Figure 1 As shown, the load-sensitive, high-flow intelligent hydraulic system module applied to bulldozers is as follows: The working condition sensing module is used to collect real-time working condition parameters of the bulldozer during operation using pressure sensors, speed sensors, rotation speed sensors and temperature sensors arranged in different locations. These parameters include the load pressure and operating speed of each actuator (such as the blade lifting / tilting cylinder and the ripper cylinder), engine speed, and hydraulic system oil temperature.

[0019] Pressure sensors: Arranged in the rodless / rod chambers of the blade lifting / tilting cylinder and the ripper cylinder, as well as the main oil circuit of the hydraulic system, the pressure sensors are piezoresistive and convert the pressure signal into a 4-20mA current signal or a 0-5V voltage signal. The sampling frequency is ≥100Hz and the acquisition range covers 0-40MPa (compatible with the rated pressure of the bulldozer hydraulic system).

[0020] Speed ​​sensor: Installed on the piston rod of the hydraulic cylinder or the output shaft of the hydraulic motor, it adopts a Hall effect speed sensor to collect the extension and retraction speed of the hydraulic cylinder (unit: mm / s) or the speed of the motor (unit: r / min), with a sampling frequency ≥50Hz and a resolution ≤1mm / s.

[0021] Speed ​​sensor: Installed on the engine flywheel housing, it collects the real-time engine speed (unit: r / min), with a sampling frequency ≥20Hz and a measurement accuracy of ±10r / min.

[0022] Temperature sensor: Located in the hydraulic oil tank or main return oil circuit, using a PT100 platinum resistance temperature sensor to collect hydraulic oil temperature (unit: °C), with a measurement range of -20°C to 120°C and an accuracy of ±1°C.

[0023] The intelligent control module is used to analyze operating parameters using a preset algorithm, calculate the total required flow rate, and generate variable pump displacement commands. Specifically: For each actuator, its required flow rate is calculated from the action speed and effective working area, using the following formula: ; in This represents the demand flow of the i-th actuator; The speed of action of the i-th actuator; The effective working area of ​​the i-th actuator (obtained through a pre-built area database, such as the area of ​​the rodless chamber of a hydraulic cylinder). This is the preset leakage coefficient for the hydraulic system; its value is limited to 1.05-1.15, determined according to a pre-built oil temperature-leakage coefficient mapping rule. For every 10°C increase in oil temperature, Increase by 0.02; The total demand flow is obtained by summing the demand flows of each implementing agency. The formula is: Total demand flow ; n represents the number of executing agencies currently in operation; The preset flow priority coefficient for the i-th actuator (determined by preset operation logic, such as steering = 1.0, blade lifting = 0.9, ripper = 0.7, the higher the priority, the larger the coefficient). Based on the total demand flow, a variable pump displacement command is generated using a pre-stored variable pump displacement-flow mapping table. The target displacement of the variable pump is calculated based on the total demand flow rate, and a variable pump displacement command is generated. The formula is: Target displacement of variable pump ; in The variable pump speed is proportional to the engine speed. = k × engine speed, where k is the transmission ratio); The volumetric efficiency of the variable pump (range limited to 0.9-0.95).

[0024] The displacement adjustment module is used to parse the displacement command of the intelligent variable pump and convert it into the target swashplate angle according to the pre-stored displacement-swashplate angle mapping table. After analyzing the swashplate deflection resistance, hydraulic oil temperature and operating condition fluctuation coefficient to determine the dynamic proportional gain, it uses the proportional adjustment algorithm to generate the adjustment current and sends it to the proportional electromagnet of the pump. After receiving the adjustment current, the proportional electromagnet outputs the corresponding thrust to drive the swashplate deflection. Specifically: Mark the target swashplate angle as the output angle; The actual deflection angle of the swashplate is collected and marked as the execution angle. Therefore, the angle deviation value = output angle - execution angle; The adjustment current is calculated using a proportional adjustment algorithm, expressed by the following formula: Adjust current ; in The target current is represented by the target swashplate angle converted using a pre-stored angle-current mapping rule; Indicates the angular deviation value; This indicates the dynamic proportional gain.

[0025] The dynamic proportional gain is obtained by comprehensively processing the real-time monitored swashplate deflection resistance, hydraulic oil temperature, and operating condition fluctuation coefficient. Additional notes: the lower the temperature, the higher the oil viscosity and the greater the damping → the dynamic proportional gain needs to be increased; the higher the temperature, the lower the viscosity and the smaller the damping → the dynamic proportional gain needs to be decreased. The greater the resistance, the more difficult it is to deflect the swashplate → the dynamic proportional gain needs to be increased to enhance the electromagnetic thrust; the smaller the resistance, the easier it is for the swashplate to overshoot → the dynamic proportional gain needs to be reduced to limit the thrust. A larger operating condition fluctuation coefficient indicates more severe fluctuations, requiring an increase in dynamic proportional gain to enhance the system's anti-interference capability.

[0026] The hydraulic oil temperature and swashplate deflection resistance monitored in real time are standardized by using the set hydraulic oil working temperature range and swashplate deflection resistance range respectively. Set the hydraulic oil operating temperature range: ; Standardized hydraulic oil temperature ;in This indicates the real-time monitored hydraulic oil temperature; when At 20°C, =0, viscosity is at its maximum; when At 80°C, =1, minimum viscosity.

[0027] Set the swashplate deflection resistance range: (Unloaded resistance) (Maximum load resistance); Standardized swashplate deflection resistance ;in This indicates the swashplate deflection resistance being monitored in real time. The greater the resistance, The closer it is to 1, the closer it is to 0.

[0028] The changes in the system's peak load pressure and total demand flow rate per unit time are obtained and denoted as the pressure change coefficient and flow rate change coefficient, respectively. The greater the change in load pressure and flow rate per unit time, the greater the drastic change in the corresponding operating conditions.

[0029] The pressure variation coefficient and the flow variation coefficient are weighted and fused to obtain the operating condition fluctuation coefficient. That is, by adjusting the pressure variation coefficient and flow change coefficient After normalization, the formula is used. The operating condition fluctuation coefficient was calculated. ,in and The weighting coefficient is preset; the smaller the operating condition fluctuation coefficient, the more stable the operating condition.

[0030] The standardized hydraulic oil temperature, swashplate deflection resistance and operating condition fluctuation coefficient are comprehensively processed to obtain the interference degree index. The interference degree index is converted into an additional coefficient and then combined with a predetermined basic proportional gain to obtain the dynamic proportional gain. The basic proportional gain is determined by the pump's hardware characteristics. It is calibrated through bench tests and represents the proportional gain that enables the swashplate angle deviation to converge quickly and without overshoot under standard operating conditions. .

[0031] The calculation process for the interference level index is as follows: That is, the temperature of the hydraulic oil Swashplate deflection resistance and operating condition fluctuation coefficient Using formula The interference level index was calculated. ,in , as well as These are the preset weighting coefficients.

[0032] The transformation is performed using a pre-built mapping rule between the interference level index and the additional coefficient; This involves setting up various index ranges corresponding to the interference level index, with each index range corresponding to an additional coefficient. The additional coefficient is set between 1.06 and 1.29, preset by technical personnel, and can be dynamically corrected and updated later. The higher the interference level index, the higher the probability of matching 1.29.

[0033] The dynamic proportional gain is obtained by multiplying the additional coefficient by the base proportional gain.

[0034] The valve group adjustment module is used to match the total flow supply after the swashplate is deflected by the corresponding output thrust. Based on the load pressure of each actuator, the actual stroke of the valve core, the oil temperature and the wear coefficient of the valve core, the flow correction coefficient is determined. Based on the flow correction coefficient and the required flow of each actuator, the valve core stroke of the electro-hydraulic proportional load sensitive valve corresponding to each actuator is corrected. Specifically: Obtain the load pressure of all actuators; Meanwhile, to protect the system, an upper limit value corresponding to the maximum load pressure is set (equal to 1.05 times the rated pressure of the hydraulic system). When the upper limit is exceeded, the pressure limiting protection is triggered.

[0035] Valve core wear reduces the actual effective opening of the valve orifice, and the lower the hydraulic oil temperature, the worse the flow of the flow at the valve orifice.

[0036] Valve orifice flow ; in This is the flow correction factor; Obtain the usage time of the valve core corresponding to each actuator, and convert it into wear amount using a pre-stored usage time-wear amount mapping table; Using formula Calculate the valve core wear coefficient ;in Let be the wear amount of the valve core corresponding to the i-th actuator. This is the maximum design stroke of the valve port; After weighted fusion of valve core wear coefficient and hydraulic oil temperature, valve core influence index is obtained. After converting valve core influence index into valve core adjustment coefficient, it is multiplied by preset reference flow coefficient to obtain flow correction coefficient. The reference flow coefficient is a constant preset under standard operating conditions, determined by the valve assembly hardware specifications. That is, through the formula Calculate the valve core influence index ;in and These are the preset weighting coefficients.

[0037] The transformation is performed using a pre-established mapping rule between the valve core influence index and the valve core adjustment coefficient; This involves setting the index ranges corresponding to the valve core influence index, with each index range corresponding to a valve core adjustment coefficient. The valve core adjustment coefficient is set in the range of 1.15-1.3, preset by technicians, and can be dynamically corrected and updated later. The larger the valve core influence index, the higher the probability of matching 1.3.

[0038] The flow correction coefficient compensates for key disturbances: reduced effective valve opening due to valve core wear; and differences in hydraulic oil flowability due to oil temperature changes, ensuring that the valve flow calculation is more in line with actual working conditions.

[0039] The effective flow area of ​​the valve orifice; Positively correlated with the actual stroke of the valve core. The actual stroke of the valve core is w; the circumferential width of the valve port is w. The pressure difference across the valve port; For pump output pressure, Let i be the load pressure of the i-th actuator; The density of the hydraulic oil; The valve flow rate calculated for each actuator is compared with the corresponding required flow rate. If the valve flow rate is lower than the required flow rate, the valve core stroke is increased; otherwise, the valve core stroke is decreased. Adjusting the valve core stroke involves calculating the absolute difference between the valve orifice flow rate and the corresponding required flow rate. This difference is then converted using a pre-stored "flow difference - valve orifice stroke" mapping table corresponding to two different sets of comparison results. After conversion, the valve orifice stroke is converted into a corresponding control current, which is sent to the proportional solenoid to drive the valve core to move. For example, "a flow difference of 0~5L / min corresponds to a stroke adjustment of 0.1mm, 5~10L / min corresponds to an adjustment of 0.2mm, and the maximum single adjustment does not exceed 0.5mm," thus avoiding shocks caused by excessive stroke adjustment.

[0040] The above formulas are all dimensionless calculations. Dimensionless calculations can be performed using various methods such as standardization, which will not be elaborated here. The formulas are derived from software simulations based on a large amount of collected data, and the preset parameters in the formulas can be set by those skilled in the art according to the actual situation.

[0041] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, ATA hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. The semiconductor medium can be a solid-state ATA hard disk.

[0042] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0043] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0044] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0045] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0046] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0047] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable ATA hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0048] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A load-sensitive, high-flow intelligent hydraulic system for bulldozers, characterized in that, Includes the following modules: Working condition sensing module: Real-time collection of working condition parameters of the bulldozer during operation, including load pressure and action speed of each actuator, engine speed, and hydraulic system oil temperature; Intelligent control module: Analyzes operating parameters using preset algorithms, calculates total demand flow, and generates variable pump displacement commands; Displacement adjustment module: It parses the displacement command of the intelligent variable pump and converts it into the target swashplate angle according to the pre-stored displacement-swashplate angle mapping table. After analyzing the swashplate deflection resistance, hydraulic oil temperature and operating condition fluctuation coefficient to determine the dynamic proportional gain, it uses the proportional adjustment algorithm to generate the adjustment current and sends it to the proportional electromagnet of the pump. After receiving the adjustment current, the proportional electromagnet outputs the corresponding thrust to drive the swashplate deflection. Valve assembly adjustment module: After the output thrust drives the swashplate to deflect, the flow correction coefficient is determined based on the load pressure of each actuator, the actual stroke of the valve core, the oil temperature, and the wear coefficient of the valve core. Based on the flow correction coefficient and the required flow of each actuator, the valve core stroke of the electro-hydraulic proportional load sensitive valve corresponding to each actuator is corrected.

2. The load-sensitive, high-flow intelligent hydraulic system for bulldozers according to claim 1, characterized in that: Logic for generating variable pump displacement instructions; For each actuator, its required flow rate is calculated from the action speed and effective working area; The total demand flow is obtained by summing the demand flows of each implementing agency. Based on the total demand flow, a variable pump displacement command is generated using a pre-stored variable pump displacement-flow mapping table. Calculate the target displacement of the variable pump based on the total demand flow and generate the variable pump displacement command.

3. The load-sensitive, high-flow intelligent hydraulic system for bulldozers according to claim 1, characterized in that: The logic for generating the adjustment current is generated using a proportional adjustment algorithm; The adjustment current is calculated using a proportional adjustment algorithm, expressed by the following formula: Adjust current ; in The target current is represented by the target swashplate angle converted using a pre-stored angle-current mapping rule; Indicates the angular deviation value; This indicates the dynamic proportional gain.

4. The load-sensitive, high-flow intelligent hydraulic system for bulldozers according to claim 3, characterized in that: Logic for calculating angle deviation; Mark the target swashplate angle as the output angle; The actual deflection angle of the swashplate is collected and marked as the execution angle. Then the angle deviation value = output angle - execution angle.

5. The load-sensitive, high-flow intelligent hydraulic system for bulldozers according to claim 3, characterized in that: Dynamic proportional gain calculation logic; It is obtained by comprehensively processing the swashplate deflection resistance, hydraulic oil temperature, and operating condition fluctuation coefficient; The hydraulic oil temperature and swashplate deflection resistance monitored in real time are standardized by using the set hydraulic oil working temperature range and swashplate deflection resistance range respectively. The standardized hydraulic oil temperature, swashplate deflection resistance, and operating condition fluctuation coefficient are comprehensively processed to obtain the interference degree index. The interference degree index is then converted into an additional coefficient and combined with a pre-determined basic proportional gain to obtain the dynamic proportional gain.

6. The load-sensitive, high-flow intelligent hydraulic system for bulldozers according to claim 5, characterized in that: Logic for obtaining operating condition fluctuation coefficient; The changes in the system's peak load pressure and total demand flow rate per unit time are obtained and denoted as the pressure change coefficient and flow rate change coefficient, respectively. The pressure variation coefficient and the flow variation coefficient are weighted and fused to obtain the operating condition fluctuation coefficient.

7. The load-sensitive, high-flow intelligent hydraulic system for bulldozers according to claim 1, characterized in that: The correction logic for valve core stroke; Obtain the load pressure of all actuators; Calculate valve flow rate using formula ; in This is the flow correction factor; The effective flow area of ​​the valve orifice; The pressure difference across the valve port; The density of the hydraulic oil; The valve flow rate calculated for each actuator is compared with the corresponding required flow rate. If the valve flow rate is lower than the required flow rate, the valve core stroke is increased; otherwise, the valve core stroke is decreased.

8. The load-sensitive, high-flow intelligent hydraulic system for bulldozers according to claim 7, characterized in that: The calculation logic for the effective flow area of ​​the valve orifice and the pressure difference across the valve orifice; The actual stroke of the valve core is w; the circumferential width of the valve port is w. For pump output pressure, Let be the load pressure of the i-th actuator.

9. The load-sensitive, high-flow intelligent hydraulic system for bulldozers according to claim 7, characterized in that: The calculation logic of the flow correction factor; Obtain the usage time of the valve core corresponding to each actuator, and convert it into wear amount using a pre-stored usage time-wear amount mapping table; Using formula Calculate the valve core wear coefficient ;in Let be the wear amount of the valve core corresponding to the i-th actuator. This is the maximum design stroke of the valve port; After weighted fusion of valve core wear coefficient and hydraulic oil temperature, valve core influence index is obtained. After converting valve core influence index into valve core adjustment coefficient, it is multiplied by preset reference flow coefficient to obtain flow correction coefficient.

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