Multi-pump linkage special transport vehicle all-wheel steering hydraulic decoupling energy-saving control system

Abstract

This multi-pump linkage special transport vehicle all-wheel steering hydraulic decoupling energy-saving control system relates to the field of special vehicle hydraulic control technology. It includes collecting data on wheel angle, vehicle speed, road conditions, and pump status; determining the vehicle's operating mode; acquiring steering gain and preset total oil supply flow of the pump group in high-speed stable mode, and target wheel angle and preset total oil supply flow of the pump group in low-speed flexible mode; performing master pump priority + slave pump stepwise activation operation based on the preset total oil supply flow of the pump group, while dynamically setting personalized stagnation and shutdown thresholds for the master pump and each level of slave pumps, and performing stepwise shutdown operation of the slave pumps based on the preset total oil supply flow and personalized stagnation and shutdown thresholds; and monitoring the master pump in real time based on pump status data, and performing fuzzy PID feedback adjustment or initiating fault redundancy operation based on the monitoring results, significantly improving the pump group's operating efficiency and avoiding energy waste.

Description

Technical Field

[0001] This invention relates to the field of hydraulic control technology for special vehicles, specifically a multi-pump linkage hydraulic decoupling and energy-saving control system for all-wheel steering of special transport vehicles. Background Technology

[0002] Chinese Patent Publication No. CN119611499A discloses an all-wheel steering system and a straddle carrier, including: a main frame, a left travel mechanism, and a right travel mechanism; the left travel mechanism includes a left frame, a left front wheel frame, a left rear wheel frame, a left front wheel, and a left rear wheel; the right travel mechanism includes a right frame, a right front wheel frame, a right rear wheel frame, a right front wheel, and a right rear wheel; a steering hydraulic system includes a hydraulic steering gear and left front hydraulic cylinder, left rear hydraulic cylinder, right front hydraulic cylinder, and right rear hydraulic cylinder, the left front hydraulic cylinder being drivenly connected to the left front wheel frame, the left rear hydraulic cylinder being drivenly connected to the left rear wheel frame, the right front hydraulic cylinder being drivenly connected to the right front wheel frame, and the right rear hydraulic cylinder being drivenly connected to the right rear wheel frame; the hydraulic steering gear is used for supplying and returning oil to the left front hydraulic cylinder, left rear hydraulic cylinder, right front hydraulic cylinder, and right rear hydraulic cylinder; a first mechanical synchronization mechanism and a second mechanical synchronization mechanism;

[0003] Chinese Patent Publication No. CN119308912A discloses a hydraulic system and engineering machinery. The hydraulic system includes a hydraulic pump, a proportional directional valve, a compensating valve, and a first relief valve. The outlet of the compensating valve is connected to the inlet of the proportional directional valve, and the inlet of the compensating valve is connected to the outlet of the hydraulic pump. The inlet of the first relief valve can selectively connect to either the first or second port of the proportional directional valve. The first chamber of the compensating valve and the inlet of the first relief valve are connected to the same port of the proportional directional valve, and the inlet of the proportional directional valve can connect to the second chamber of the compensating valve. The first and second chambers are located on opposite sides of the compensating valve.

[0004] Although the aforementioned existing technologies involve multi-pump linkage and hydraulic decoupling, they have not achieved deep integration of multi-mode steering, intelligent flow distribution and energy-saving control, making it difficult to meet the high-precision and low-energy consumption requirements under extreme working conditions. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a multi-pump linkage special transport vehicle all-wheel steering hydraulic decoupling energy-saving control system, comprising the following steps:

[0006] like Figure 1 As shown, the multi-pump linkage special transport vehicle all-wheel steering hydraulic decoupling energy-saving control system includes a control center, which is communicatively connected to a data acquisition module, a flexible control module, a parameter analysis module, a multi-pump linkage control module, and a main pump monitoring module.

[0007] The data acquisition module is used to collect data on wheel angle, vehicle speed, road conditions, and pump status of special transport vehicles, and to mark the collection time and set the collection cycle.

[0008] The flexible control module is used to dynamically adjust the operating mode of the special transport vehicle according to the wheel angle and vehicle speed;

[0009] The parameter analysis module is used to obtain the steering gain and the preset total fuel supply flow of the pump group in the high-speed stable mode based on vehicle speed, and to obtain the target steering angle of each wheel and the preset total fuel supply flow of the pump group in the low-speed flexible mode based on wheel steering angle and road condition data.

[0010] The multi-pump linkage control module is used to perform the main pump priority + slave pump step activation operation according to the preset total oil supply flow of the pump group, and at the same time dynamically set the personalized stagnation and shutdown threshold of the main pump and each level of slave pump, and perform the slave pump step shutdown operation according to the preset total oil supply flow and personalized stagnation and shutdown threshold.

[0011] The main pump monitoring module is used to monitor the main pump in real time based on the pump set status data, and to perform fuzzy PID feedback adjustment or start fault redundancy operation based on the monitoring results.

[0012] Furthermore, the process by which the flexible control module dynamically adjusts the operating mode of the special transport vehicle based on wheel angle and vehicle speed includes:

[0013] Preset trigger conditions for different operating modes, including high-speed stable mode and low-speed flexible mode, and the trigger conditions include threshold ranges for wheel angle and vehicle speed.

[0014] Obtain the time-series numerical data corresponding to wheel angle and vehicle speed within the current collection period. Calculate the average values ​​of wheel angle and vehicle speed based on the time-series numerical data. Compare the average values ​​of wheel angle and vehicle speed with the trigger conditions corresponding to different operating modes to obtain the threshold intervals to which the average values ​​of wheel angle and vehicle speed belong. Based on the threshold intervals to which the average values ​​of wheel angle and vehicle speed belong, obtain the operating mode of the special transport vehicle.

[0015] Furthermore, the process by which the parameter analysis module obtains the steering gain and the preset total fuel supply flow of the pump unit in high-speed stable mode includes:

[0016] When the special transport vehicle is in high-speed stable mode, a variable steering gain steering analysis is performed on the special transport vehicle based on the average vehicle speed to obtain the dynamically adjusted steering gain, and the maximum flow rate of the steering cylinder corresponding to each wheel of the special transport vehicle is obtained based on the average vehicle speed.

[0017] Obtain the functional relationship between the average vehicle speed and the steering system flow demand coefficient, as well as the system efficiency coefficient. Based on the functional relationship between the average vehicle speed and the steering system flow demand coefficient, obtain the steering system flow demand coefficient corresponding to the current average vehicle speed.

[0018] Based on the flow demand coefficient of the steering system and the maximum flow rate of the steering cylinder corresponding to each wheel, the actual flow demand of each steering cylinder at the current vehicle speed is obtained. Based on the actual flow demand of each steering cylinder and the system efficiency coefficient, the preset total oil supply flow rate of the pump set at the current moment is determined.

[0019] Furthermore, the process of obtaining the dynamically adjusted steering gain by performing a steering analysis on the special transport vehicle based on the average vehicle speed includes:

[0020]

[0021] Among them, K gain (v) represents the dynamically adjusted steering gain, K max For maximum gain at low speed, K min For high-speed minimum gain, v is the average vehicle speed. ref The vehicle speed is a characteristic of gain attenuation.

[0022] The process of obtaining the maximum flow rate of the steering cylinders corresponding to each wheel of a special transport vehicle based on the average vehicle speed includes:

[0023]

[0024] Among them, Q lim For the maximum flow rate of the steering cylinder, ω wheel_max (v) represents the maximum permissible wheel steering angular velocity based on the current vehicle speed average. cyl For the displacement of the steering cylinder, η v For volumetric efficiency;

[0025] The functional relationship between the average vehicle speed and the steering system flow demand coefficient is as follows:

[0026]

[0027] Where, k v k is the flow demand coefficient for the steering system. max =1 (The flow demand coefficient is 1 at low speeds; the higher the vehicle speed, the smaller the steering demand, and the smaller the flow required by the steering system), v min The low-speed threshold (e.g., 10 km / h);

[0028] The process of obtaining the actual flow demand of each steering cylinder at the current vehicle speed, based on the steering system flow demand coefficient and the maximum flow rate of the steering cylinder corresponding to each wheel, is as follows:

[0029] Q i =k v ×Q lim-i ;

[0030] Among them, Q i Q represents the actual flow rate requirement of the steering cylinder corresponding to wheel i at the current average vehicle speed. lim-i This indicates the maximum flow rate of the steering cylinder corresponding to wheel i;

[0031] The formula for calculating the preset total oil supply flow rate of the pump set is:

[0032]

[0033] Among them, Q total Here, η represents the preset total oil supply flow rate of the pump unit, η is the system efficiency coefficient, and n represents the number of wheels of the special transport vehicle. All the above formulas are dimensionless calculations, derived from software simulation using collected data to arrive at a formula that most closely approximates reality. The preset parameters in the formulas are set by those skilled in the art based on actual conditions or obtained through extensive data simulation.

[0034] Furthermore, the process by which the parameter analysis module obtains the target steering angle of each wheel and the preset total oil supply flow of the pump unit in low-speed flexible mode includes:

[0035] When the special transport vehicle is in low-speed flexible mode, the target turning angle of each wheel of the special transport vehicle is determined based on the road condition data and Ackerman steering geometry. The real-time steering angular velocity of each wheel is obtained based on the numerical time sequence corresponding to the wheel turning angle of each wheel. The preset total oil supply flow of the pump group at the current moment is determined based on the real-time steering angular velocity of each wheel, the displacement of the steering cylinder corresponding to each wheel and the system efficiency coefficient.

[0036] Specifically, the target steering angle α of each wheel of the special transport vehicle is determined based on road condition data and Ackerman steering geometry. i :

[0037]

[0038] Where, α inner-i α represents the inner rotation angle of wheel i. outer-i The outer turning angle of wheel i is represented by , L is the wheelbase of the special transport vehicle, R is the turning radius obtained from road condition data, and W is the track width of the special transport vehicle.

[0039] The total oil supply flow rate Q of the pump set at the current moment is determined based on the real-time steering angular velocity of each wheel, the displacement of the steering cylinder corresponding to each wheel, and the system efficiency coefficient. total :

[0040]

[0041] in, v represents the real-time steering angular velocity of wheel i. cyl-i This indicates the displacement of the steering cylinder corresponding to wheel i.

[0042] Furthermore, the multi-pump linkage control module performs a master pump priority + slave pump step-by-step activation operation based on the preset total oil supply flow of the pump set, and a slave pump step-by-step shutdown operation based on the preset total oil supply flow and a personalized stagnation shutdown threshold, including the following process:

[0043] The pump set consists of a main pump and several slave pumps, obtaining the maximum oil supply flow rate of the main pump and the maximum oil supply flow rate of several slave pumps (the maximum oil supply flow rate of several slave pumps is equal);

[0044] The preset safety margin is compared with the difference between the preset total oil supply flow and the maximum oil supply flow of the main pump and the safety margin. If the preset total oil supply flow is less than or equal to the difference between the maximum oil supply flow of the main pump and the safety margin, the output oil supply of the main pump is adjusted according to the preset total oil supply flow.

[0045] When the preset total oil supply flow rate is greater than the difference between the maximum oil supply flow rate of the main pump and the safety margin, the number of slave pumps to be activated is obtained based on the preset total oil supply flow rate, the maximum oil supply flow rate of the slave pump, and the difference between the maximum oil supply flow rate of the main pump and the safety margin. The activation order of several slave pumps is preset, and each level of slave pump is started sequentially according to the number of slave pumps to be activated and the activation order of several slave pumps (the first slave pump started is marked as a level one slave pump, the second slave pump started is marked as a level two slave pump, and so on, with the xth slave pump started being marked as a level x slave pump).

[0046] The formula for calculating the number of slave pumps to be activated is as follows, based on the preset total oil supply flow rate, the maximum oil supply flow rate of the slave pump, and the difference between the maximum oil supply flow rate of the main pump and the safety margin:

[0047]

[0048] in, Indicates rounding up, n 需激活从泵 To determine the number of pumps that need to be activated, Q 主泵_max The maximum oil supply flow rate of the main pump, δ c For safety margin, Q 从泵_max This is the maximum oil supply flow rate from the pump;

[0049] If the number of slave pumps to be activated is equal to one, then set the personalized stagnation shutdown threshold of the main pump. When the preset total oil supply flow is less than the personalized stagnation shutdown threshold, the slave pump will be shut down.

[0050] If more than one slave pump needs to be activated, set the personalized stagnation and shutdown threshold for the main pump and all slave pumps except the last stage slave pump (the last started slave pump), and compare the preset total oil supply flow with the personalized stagnation and shutdown threshold for the main pump and all slave pumps except the last stage slave pump.

[0051] If the preset total oil supply flow rate is less than the personalized stagnation shutdown threshold of the main pump, all slave pumps are shut down. If the preset total oil supply flow rate is less than the personalized stagnation shutdown threshold of a certain slave pump, all slave pumps whose activation sequence follows that slave pump are shut down.

[0052] Furthermore, the process of dynamically setting personalized stagnation shut-off thresholds for the main pump and each stage of slave pumps includes:

[0053] Obtain the numerical time series corresponding to the preset total oil supply flow within the current acquisition period, perform statistical analysis on the numerical time series, and obtain the average fluctuating oil volume of the preset total oil supply flow.

[0054] The calculation process for obtaining the average fluctuating oil volume of the preset total oil supply flow rate is as follows:

[0055]

[0056] Among them, Q z Q represents the average fluctuating oil volume. total(t) represents the preset total fuel supply flow rate at time t, and N represents the total number of times in the numerical time series corresponding to the preset total fuel supply flow rate;

[0057] The personalized stagnation shut-off threshold of the main pump is obtained based on the maximum oil supply flow rate and average fluctuating oil volume of the main pump.

[0058] The individualized retention shut-off thresholds for each stage of the slave pump are obtained based on the maximum oil supply flow of the main pump, the maximum oil supply flow of several slave pumps, and the average fluctuating oil volume.

[0059] Furthermore, the calculation process for obtaining the personalized stagnation shut-off threshold of the main pump based on the maximum oil supply flow rate and average fluctuating oil volume of the main pump is as follows:

[0060] Q 主泵_off =Q 主泵_max -Q z ;

[0061] Among them, Q 主泵_off This indicates the individualized dwell-off threshold of the main pump;

[0062] The calculation process for obtaining the individualized retention shut-off threshold of each pump stage is as follows:

[0063]

[0064] Among them, Q从泵_off_m Q represents the personalized stagnation shut-off threshold of the m-th stage pump. 从泵_max_j This represents the maximum oil supply flow rate of the j-th stage pump; |j|≤|m|.

[0065] Furthermore, the process by which the energy-saving control module adjusts the output oil supply of the main pump to achieve maximum energy conversion efficiency based on the preset total oil supply flow includes:

[0066] An efficiency comparison table is pre-constructed, which includes the energy conversion efficiency corresponding to different displacements and motor speeds under different preset total oil supply flow rates and different operating modes.

[0067] Based on the preset total oil supply flow, operating mode, and efficiency comparison table, obtain the displacement and motor speed corresponding to the maximum energy conversion efficiency of the main pump, and adjust the main pump according to the displacement and motor speed corresponding to the maximum energy conversion efficiency.

[0068] Furthermore, the main pump monitoring module monitors the main pump in real time based on pump set status data, and the process of adjusting the main pump using fuzzy PID feedback or initiating fault redundancy operation based on the monitoring results includes:

[0069] The supply power is obtained by acquiring the inlet and outlet pressure difference of the main pump, the output oil supply, and the system efficiency coefficient based on the pump set status data; the demand power is obtained by acquiring the inlet and outlet pressure difference of the main pump, the preset total oil supply flow, and the system efficiency coefficient.

[0070] The formulas for obtaining the power supply and power demand are as follows:

[0071]

[0072] Among them, P target For the required power, P actual To supply power, p is the pressure difference between the inlet and outlet of the main pump, and Q is the pressure difference between the inlet and outlet of the main pump. actual To output fuel supply;

[0073] The power deviation is obtained based on the power demand and the power supply. A power deviation threshold is preset. If the power deviation is greater than the power deviation threshold, the main pump is marked as having an abnormal power state and fault redundancy operation is initiated. If the power deviation is less than or equal to the power deviation threshold, the main pump is adjusted by fuzzy PID feedback.

[0074] Furthermore, the process of fuzzy PID feedback regulation of the main pump includes:

[0075] The power deviation at the current time and the previous time is obtained. The power deviation change rate is obtained based on the power deviation at the current time and the previous time. The power deviation at the current time and the power deviation change rate are used as evaluation indicators. The membership matrix and fuzzy rule base are predefined. The PID adjustment parameters corresponding to the evaluation indicators are obtained through fuzzy comprehensive evaluation.

[0076] The process of obtaining the PID control parameters corresponding to the evaluation index through fuzzy comprehensive evaluation includes:

[0077] The power deviation change rate is:

[0078]

[0079] Where EC(t) is the rate of change of power deviation at time t, Δt is the acquisition period (s), E(t-Δt) is the power deviation at the previous time, and E(t) is the power deviation at the current time.

[0080] Convert continuous E(t) and EC(t) into fuzzy linguistic variables:

[0081] Power deviation E(t): {Negative large (NB), negative medium (NM), negative small (NS), zero (ZO), positive small (PS), positive medium (PM), positive large (PB)};

[0082] Deviation change rate EC(t): {Negative fast (NB), negative medium (NM), negative slow (NS), zero (ZO), positive slow (PS), positive medium (PM), positive fast (PB)};

[0083] Example: When a sudden increase in steering load causes E(t) to exceed 20% of the rated power, E(t) belongs to "positive (PB)"; if EC(t) rises rapidly, it belongs to "positive fast (PB)".

[0084] The core logic for developing a fuzzy rule base based on expert experience is as follows:

[0085] When the operating conditions are stable (e.g., E(t)≈0, EC(t)≈0): decrease K p To avoid overshoot, increase K. i Eliminate steady-state error;

[0086] When demand surges (e.g., E(t) > 0 and EC(t) > 0): Increase K p Quick response, appropriately reduce K d Prevent high-frequency oscillation;

[0087] The fuzzy output is calculated using the Mamdani inference method and then converted to an accurate value using the centroid method.

[0088] K p =K p0 +u(ΔKp );

[0089] K i =K i0 +u(ΔK i );

[0090] K d =K d0 +u(ΔK d );

[0091] Among them, K p0 K i0 K d0 Here are the initial PID parameters, u(·) is the adjustment amount after defuzzification, and K... p K i K d These are the PID control parameters;

[0092] A PID control model is constructed, the PID adjustment parameters are input into the PID control model, the pump flow rate adjustment signal is output according to the PID control model, and the main pump displacement and motor speed are adjusted based on the pump flow rate adjustment signal.

[0093] Furthermore, the specific process of inputting the PID adjustment parameters into the PID control model and outputting the pump flow adjustment signal according to the PID control model is as follows:

[0094]

[0095] Among them, Q cmd This is a pump flow rate adjustment signal;

[0096] The specific process of feedback adjustment of the main pump displacement and motor speed based on the pump flow rate adjustment signal is as follows:

[0097] The pump flow rate to be adjusted is determined based on the pump flow rate adjustment signal. The preset total oil supply flow rate is adjusted based on the pump flow rate to be adjusted to obtain the adjusted preset total oil supply flow rate. The adjusted preset total oil supply flow rate = preset total oil supply flow rate + pump flow rate to be adjusted. Based on the adjusted preset total oil supply flow rate, operating mode and efficiency comparison table, the displacement and motor speed corresponding to the maximum energy conversion efficiency of the main pump are obtained. The main pump is then adjusted based on the displacement and motor speed.

[0098] Furthermore, the process of activating the fault redundancy mode includes:

[0099] Suspend the main pump operation, obtain the number of slave pumps to be activated based on the preset total oil supply flow and the maximum oil supply flow of the slave pumps, start each level of slave pumps in sequence according to the number of slave pumps to be activated and the activation order of several slave pumps, and set the personalized stagnation and shutdown thresholds for each level of slave pumps excluding the last level of slave pumps.

[0100] The formula for calculating the number of slave pumps to be activated, based on the preset total oil supply flow rate and the maximum oil supply flow rate of the slave pump, is as follows:

[0101]

[0102] The calculation process for setting the personalized lingering shutdown threshold for each slave pump, excluding the last-stage slave pump, is as follows:

[0103]

[0104] The preset total oil supply flow rate is compared with the individualized stagnation shut-off threshold of each slave pump, excluding the last stage slave pump;

[0105] If the preset total oil supply flow rate is less than the personalized stagnation shutdown threshold of a certain stage slave pump, then all slave pumps whose activation sequence follows that stage slave pump will be shut down.

[0106] Compared with the prior art, the beneficial effects of the present invention are:

[0107] 1. Precise operation mode switching: Through the flexible control module, the operation mode is dynamically adjusted according to the wheel angle and vehicle speed, which can accurately match different driving conditions such as high-speed stability and low-speed flexibility, thereby improving vehicle handling and adaptability.

[0108] 2. Optimized parameter analysis: The parameter analysis module can accurately obtain the steering gain and preset total oil supply flow of the pump group in high-speed stable mode, as well as the target steering angle of each wheel and preset total oil supply flow of the pump group in low-speed flexible mode, based on multi-dimensional data such as vehicle speed, wheel angle and road conditions. This provides accurate parameter support for vehicle steering and improves steering accuracy and stability.

[0109] 3. High-efficiency multi-pump linkage control: The multi-pump linkage control module adopts a master pump priority + slave pump step-by-step activation and shutdown strategy, and can dynamically set personalized stagnation shutdown thresholds, effectively improving the operating efficiency of the pump group, avoiding energy waste, and achieving energy-saving operation.

[0110] 4. Intelligent monitoring and regulation of the main pump: The main pump monitoring module monitors the status of the main pump in real time. Through fuzzy PID feedback regulation, it can quickly respond to power deviations and accurately adjust the main pump displacement and motor speed, thereby improving the stability and energy efficiency of the system. At the same time, the fault redundancy operation can ensure the normal operation of the system when the main pump is abnormal, thereby enhancing the reliability and fault tolerance of the system.

[0111] 5. System Integration and Collaborative Optimization: Through communication connections with various modules, the control center achieves integrated and collaborative operation of data acquisition, analysis, and control functions. This enables the entire system to perform global optimization based on the actual operating status of the vehicle, improving the overall performance of the special transport vehicle's all-wheel steering hydraulic system, including energy saving, steering accuracy, system stability, and reliability. Attached Figure Description

[0112] Figure 1 This is a schematic diagram of the multi-pump linkage special transport vehicle all-wheel steering hydraulic decoupling energy-saving control system according to an embodiment of this application. Detailed Implementation

[0113] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0114] like Figure 1 As shown, the multi-pump linkage special transport vehicle all-wheel steering hydraulic decoupling energy-saving control system includes a control center, which is communicatively connected to a data acquisition module, a flexible control module, a parameter analysis module, a multi-pump linkage control module, and a main pump monitoring module.

[0115] The data acquisition module is used to collect data on wheel angle, vehicle speed, road conditions, and pump status of special transport vehicles, and to mark the collection time and set the collection cycle (usually 10 seconds).

[0116] The flexible control module is used to dynamically adjust the operating mode of the special transport vehicle according to the wheel angle and vehicle speed;

[0117] The parameter analysis module is used to obtain the steering gain and the preset total fuel supply flow of the pump group in the high-speed stable mode based on vehicle speed, and to obtain the target steering angle of each wheel and the preset total fuel supply flow of the pump group in the low-speed flexible mode based on wheel steering angle and road condition data.

[0118] The multi-pump linkage control module is used to perform the main pump priority + slave pump step activation operation according to the preset total oil supply flow of the pump group, and at the same time dynamically set the personalized stagnation and shutdown threshold of the main pump and each level of slave pump, and perform the slave pump step shutdown operation according to the preset total oil supply flow and personalized stagnation and shutdown threshold.

[0119] The main pump monitoring module is used to monitor the main pump in real time based on the pump set status data, and to perform fuzzy PID feedback adjustment or start fault redundancy operation based on the monitoring results.

[0120] It should be further explained that, in the specific implementation process, the flexible control module dynamically adjusts the operating mode of the special transport vehicle based on the wheel angle and vehicle speed, including the following:

[0121] Preset trigger conditions for different operating modes, including high-speed stable mode and low-speed flexible mode, and the trigger conditions include threshold ranges for wheel angle and vehicle speed.

[0122] Obtain the time-series numerical data corresponding to wheel angle and vehicle speed within the current collection period. Calculate the average values ​​of wheel angle and vehicle speed based on the time-series numerical data. Compare the average values ​​of wheel angle and vehicle speed with the trigger conditions corresponding to different operating modes to obtain the threshold intervals to which the average values ​​of wheel angle and vehicle speed belong. Based on the threshold intervals to which the average values ​​of wheel angle and vehicle speed belong, obtain the operating mode of the special transport vehicle.

[0123] By switching between multiple modes and controlling variable parameters, the steering system gain is reduced in the high-speed stable mode, so that the wheel angle and the wheel steering angle have a non-linear relationship, avoiding vehicle yaw fluctuations caused by small inputs at high speeds. In the low-speed agile mode, the wheel steering angle is maximized (such as ±45° deflection of all wheels), achieving the minimum turning radius, balancing high-speed stability and low-speed agility, while the steering response time is shortened by 30% compared to the traditional system.

[0124] It should be further explained that, in the specific implementation process, the parameter analysis module obtains the steering gain and the preset total fuel supply flow of the pump group in high-speed stable mode, including:

[0125] When the special transport vehicle is in high-speed stable mode, a variable steering gain steering analysis is performed on the special transport vehicle based on the average vehicle speed to obtain the dynamically adjusted steering gain. In high-speed stable mode, the steering system gain is reduced to make the wheel angle and wheel steering angle have a non-linear relationship, avoiding vehicle yaw fluctuation caused by small high-speed inputs. The maximum flow rate of the steering cylinder corresponding to each wheel of the special transport vehicle is obtained based on the average vehicle speed.

[0126] Based on the concept of simulation learning, an simulator is used to fit experiments and obtain the functional relationship between the average vehicle speed and the steering system flow demand coefficient (the higher the vehicle speed, the smaller the steering demand, and the smaller the flow required by the steering system) and the system efficiency coefficient (due to factors such as leakage and pipeline resistance in the hydraulic system, flow loss will occur, so the system efficiency coefficient is introduced. The system efficiency coefficient is generally between 0.8 and 0.9, which reflects the proportion of flow actually obtained by each steering cylinder from the pump output of the hydraulic system). Based on the functional relationship between the average vehicle speed and the steering system flow demand coefficient, the steering system flow demand coefficient corresponding to the current average vehicle speed is obtained.

[0127] Based on the flow demand coefficient of the steering system and the maximum flow rate of the steering cylinder corresponding to each wheel, the actual flow demand of each steering cylinder at the current vehicle speed is obtained. Based on the actual flow demand of each steering cylinder and the system efficiency coefficient, the preset total oil supply flow rate of the pump set at the current moment is determined.

[0128] It should be further explained that the process of obtaining the dynamically adjusted steering gain by performing a steering analysis on a special transport vehicle based on the average vehicle speed includes:

[0129]

[0130] Among them, K gain (v) represents the dynamically adjusted steering gain, K max For maximum gain at low speed, K min For high-speed minimum gain, v is the average vehicle speed. ref The vehicle speed is a characteristic of gain attenuation.

[0131] The process of obtaining the maximum flow rate of the steering cylinders corresponding to each wheel of a special transport vehicle based on the average vehicle speed includes:

[0132]

[0133] Among them, Q lim For the maximum flow rate of the steering cylinder, ω wheel_max (v) represents the maximum permissible wheel steering angular velocity based on the current vehicle speed average. cyl For the displacement of the steering cylinder, η v For volumetric efficiency;

[0134] The functional relationship between the average vehicle speed and the steering system flow demand coefficient is as follows:

[0135]

[0136] Where, k v k is the flow demand coefficient for the steering system. max =1 (The flow demand coefficient is 1 at low speeds; the higher the vehicle speed, the smaller the steering demand, and the smaller the flow required by the steering system), v min The low-speed threshold (e.g., 10 km / h);

[0137] The process of obtaining the actual flow demand of each steering cylinder at the current vehicle speed, based on the steering system flow demand coefficient and the maximum flow rate of the steering cylinder corresponding to each wheel, is as follows:

[0138] Q i =k v ×Q lim-i ;

[0139] Among them, Q i Q represents the actual flow rate requirement of the steering cylinder corresponding to wheel i at the current average vehicle speed. lim-i This indicates the maximum flow rate of the steering cylinder corresponding to wheel i;

[0140] The formula for calculating the preset total oil supply flow rate of the pump set is:

[0141]

[0142] Among them, Q total Here, η represents the preset total oil supply flow rate of the pump unit, η is the system efficiency coefficient, and n represents the number of wheels of the special transport vehicle. All the above formulas are dimensionless calculations, derived from software simulation using collected data to arrive at a formula that most closely approximates reality. The preset parameters in the formulas are set by those skilled in the art based on actual conditions or obtained through extensive data simulation.

[0143] It should be further explained that, in the specific implementation process, the parameter analysis module obtains the target steering angle of each wheel and the preset total oil supply flow of the pump group in the low-speed flexible mode, including:

[0144] When the special transport vehicle is in low-speed flexible mode, the target turning angle of each wheel of the special transport vehicle is determined based on the Ackerman steering geometry according to the road condition data. In low-speed flexible mode, the wheel steering angle is maximized (such as ±45° deflection of all wheels) to achieve the minimum turning radius. The real-time steering angular velocity of each wheel is obtained according to the numerical time sequence corresponding to the wheel turning angle of each wheel. The preset total oil supply flow of the pump group at the current moment is determined according to the real-time steering angular velocity of each wheel, the displacement of the steering cylinder corresponding to each wheel and the system efficiency coefficient.

[0145] Specifically, the target steering angle α of each wheel of the special transport vehicle is determined based on road condition data and Ackerman steering geometry. i :

[0146]

[0147] Where, α inner-i α represents the inner rotation angle of wheel i. outer-i The outer turning angle of wheel i is represented by , L is the wheelbase of the special transport vehicle, R is the turning radius obtained from road condition data, and W is the track width of the special transport vehicle.

[0148] The total oil supply flow rate Q of the pump set at the current moment is determined based on the real-time steering angular velocity of each wheel, the displacement of the steering cylinder corresponding to each wheel, and the system efficiency coefficient. total :

[0149]

[0150] in, v represents the real-time steering angular velocity of wheel i. cyl-i This indicates the displacement of the steering cylinder corresponding to wheel i.

[0151] It should be further explained that, in the specific implementation process, the multi-pump linkage control module performs a master pump priority + slave pump step-by-step activation operation based on the preset total oil supply flow of the pump set, and a slave pump step-by-step shutdown operation based on the preset total oil supply flow and a personalized stagnation shutdown threshold, including the following:

[0152] The pump set consists of a main pump and several slave pumps. The main pump is an electro-hydraulic proportional variable pump, whose displacement can be dynamically adjusted according to demand. The slave pumps are fixed displacement pumps. When the system requires flow, the main pump first provides the required flow by adjusting its displacement and motor speed. If the maximum oil supply flow of the main pump is insufficient to meet the demand, the slave pumps are started in a stepwise manner, increasing the flow of one slave pump at a time until the total demand is met. This strategy can more accurately match the flow demand, reduce energy waste, and reduce the number of start-stop cycles of the slave pumps, extending their lifespan. In contrast, traditional multi-pump systems typically use fixed displacement pumps, meaning that the pump's output flow range is fixed and cannot be dynamically adjusted according to actual demand. When the system needs more flow, more pumps may be started, and when demand decreases, some pumps may be stopped. This control method suffers from uneven flow distribution because the output of each pump is fixed, making it impossible to accurately match the demand, resulting in energy waste. In addition, frequent start-stop cycles increase pump wear and reduce lifespan.

[0153] Obtain the maximum oil supply flow rate of the main pump and the maximum oil supply flow rate of several slave pumps (the maximum oil supply flow rates of the several slave pumps are equal);

[0154] The preset safety margin is compared with the difference between the preset total oil supply flow and the maximum oil supply flow of the main pump and the safety margin. If the preset total oil supply flow is less than or equal to the difference between the maximum oil supply flow of the main pump and the safety margin, the output oil supply of the main pump is adjusted according to the preset total oil supply flow.

[0155] When the preset total oil supply flow rate is greater than the difference between the maximum oil supply flow rate of the main pump and the safety margin, the number of slave pumps to be activated is obtained based on the preset total oil supply flow rate, the maximum oil supply flow rate of the slave pump, and the difference between the maximum oil supply flow rate of the main pump and the safety margin. The activation order of several slave pumps is preset, and each level of slave pump is started sequentially according to the number of slave pumps to be activated and the activation order of several slave pumps (the first slave pump started is marked as a level one slave pump, the second slave pump started is marked as a level two slave pump, and so on, with the xth slave pump started being marked as a level x slave pump).

[0156] The formula for calculating the number of slave pumps to be activated is as follows, based on the preset total oil supply flow rate, the maximum oil supply flow rate of the slave pump, and the difference between the maximum oil supply flow rate of the main pump and the safety margin:

[0157]

[0158] in, Indicates rounding up, n 需激活从泵 To determine the number of pumps that need to be activated, Q 主泵_max The maximum oil supply flow rate of the main pump, δ c For safety margin, Q 从泵_max This is the maximum oil supply flow rate from the pump;

[0159] If the number of slave pumps to be activated is equal to one, then set the personalized stagnation shutdown threshold of the main pump. When the preset total oil supply flow is less than the personalized stagnation shutdown threshold, the slave pump will be shut down.

[0160] If more than one slave pump needs to be activated, set the personalized stagnation and shutdown threshold for the main pump and all slave pumps except the last stage slave pump (the last started slave pump), and compare the preset total oil supply flow with the personalized stagnation and shutdown threshold for the main pump and all slave pumps except the last stage slave pump.

[0161] If the preset total oil supply flow rate is less than the personalized stagnation shutdown threshold of the main pump, all slave pumps are shut down. If the preset total oil supply flow rate is less than the personalized stagnation shutdown threshold of a certain slave pump, all slave pumps whose activation sequence follows that slave pump are shut down.

[0162] It should be further explained that, in the specific implementation process, the process of dynamically setting the personalized stagnation and shutdown thresholds for the main pump and each stage of slave pumps includes:

[0163] Obtain the numerical time series corresponding to the preset total oil supply flow within the current acquisition period, perform statistical analysis on the numerical time series, and obtain the average fluctuating oil volume of the preset total oil supply flow.

[0164] The calculation process for obtaining the average fluctuating oil volume of the preset total oil supply flow rate is as follows:

[0165]

[0166] Among them, Q z Q represents the average fluctuating oil volume. total(t) represents the preset total fuel supply flow rate at time t, and N represents the total number of times in the numerical time series corresponding to the preset total fuel supply flow rate;

[0167] The personalized stagnation shut-off threshold of the main pump is obtained based on the maximum oil supply flow rate and average fluctuating oil volume of the main pump.

[0168] The individualized retention shut-off thresholds for each stage of the slave pump are obtained based on the maximum oil supply flow of the main pump, the maximum oil supply flow of several slave pumps, and the average fluctuating oil volume.

[0169] It should be further explained that, in the specific implementation process, the calculation process for obtaining the personalized stagnation shut-off threshold of the main pump based on the maximum oil supply flow rate and average fluctuating oil volume of the main pump is as follows:

[0170] Q 主泵_off =Q 主泵_max -Q z ;

[0171] Among them, Q 主泵_off This indicates the individualized dwell-off threshold of the main pump;

[0172] The calculation process for obtaining the individualized retention shut-off threshold of each pump stage is as follows:

[0173]

[0174] Among them, Q 从泵_off_m Q represents the personalized stagnation shut-off threshold of the m-th stage pump. 从泵_max_j This represents the maximum oil supply flow rate of the j-th stage pump; |j|≤|m|.

[0175] To avoid frequent pump start-stop and energy waste, a personalized stagnation and shutdown threshold can be set. For example, when the preset total oil supply flow exceeds the difference between the main pump's maximum oil supply flow and the safety margin, the first slave pump is started. To avoid frequent start-stop, the shutdown threshold should be lower than the main pump's maximum oil supply flow. This way, when the preset total oil supply flow decreases, the slave pump will not be shut down immediately until the preset total oil volume is lower than the shutdown threshold, preventing back-and-forth switching. Compared to traditional systems (pump start-stop frequency ≥ 20 times / hour), the personalized stagnation and shutdown threshold reduces the start-stop frequency to ≤ 5 times / hour, extends pump life by 25%, and reduces energy consumption by 40%.

[0176] It should be further explained that, in the specific implementation process, the energy-saving control module adjusts the output oil supply of the main pump according to the preset total oil supply flow rate with maximum energy conversion efficiency, including the following steps:

[0177] Since the main pump is an electro-hydraulic proportional variable pump, its displacement and motor speed can be dynamically adjusted according to demand. Its output oil supply is determined by both the variable displacement and the motor speed. The driven pump, on the other hand, is a fixed displacement pump with a fixed displacement. Therefore, the driven pump can only adjust its motor speed to change its oil supply. The output oil supply of the main pump is determined by both the fixed displacement and the motor speed. Furthermore, the efficiency of the main pump varies depending on the specific conditions in which the variable displacement and motor speed are converted. For example, when there is a low-speed, high-flow demand, the displacement V is increased first (to avoid motor overspeed); when there is a high-speed, low-flow demand, the speed n is decreased first (to avoid excessive leakage due to insufficient displacement); when driving at high speed, the steering demand is small, so the main pump displacement V is reduced. Even if n remains unchanged, the flow rate Q will decrease, achieving energy savings. Therefore, an efficiency diagram based on the pump is pre-constructed (the energy conversion efficiency η under different V and n is measured). 主泵 η 主泵 (This represents the ratio of actual output power to required power) to achieve maximum energy conversion efficiency;

[0178] Based on the concept of simulation learning, simulation experiments are conducted in advance to construct an efficiency comparison table, which includes the energy conversion efficiency corresponding to different displacements and motor speeds under different preset total oil supply flow rates and different operating modes.

[0179] Based on the preset total oil supply flow, operating mode, and efficiency comparison table, obtain the displacement and motor speed corresponding to the maximum energy conversion efficiency of the main pump, and adjust the main pump according to the displacement and motor speed corresponding to the maximum energy conversion efficiency.

[0180] It should be further explained that, in the specific implementation process, the main pump monitoring module monitors the main pump in real time based on the pump set status data, and the process of adjusting the main pump using fuzzy PID feedback or initiating fault redundancy operation based on the monitoring results includes:

[0181] The supply power is obtained by acquiring the inlet and outlet pressure difference of the main pump, the output oil supply, and the system efficiency coefficient based on the pump set status data; the demand power is obtained by acquiring the inlet and outlet pressure difference of the main pump, the preset total oil supply flow, and the system efficiency coefficient.

[0182] The formulas for obtaining the power supply and power demand are as follows:

[0183]

[0184] Among them, P target For the required power, P actual To supply power, p is the pressure difference between the inlet and outlet of the main pump, and Q is the pressure difference between the inlet and outlet of the main pump. actual To output fuel supply;

[0185] The power deviation is obtained based on the power demand and the power supply. A power deviation threshold is preset. If the power deviation is greater than the power deviation threshold, the main pump is marked as having an abnormal power state and fault redundancy operation is initiated. If the power deviation is less than or equal to the power deviation threshold, the main pump is adjusted by fuzzy PID feedback.

[0186] It should be further explained that, in the specific implementation process, the process of fuzzy PID feedback regulation of the main pump includes:

[0187] The power deviation at the current time and the previous time is obtained. The power deviation change rate is obtained based on the power deviation at the current time and the previous time. The power deviation at the current time and the power deviation change rate are used as evaluation indicators. The membership matrix and fuzzy rule base are predefined. The PID adjustment parameters corresponding to the evaluation indicators are obtained through fuzzy comprehensive evaluation.

[0188] The process of obtaining the PID control parameters corresponding to the evaluation index through fuzzy comprehensive evaluation includes:

[0189] The power deviation change rate is:

[0190]

[0191] Where EC(t) is the rate of change of power deviation at time t, Δt is the acquisition period (s), E(t-Δt) is the power deviation at the previous time, and E(t) is the power deviation at the current time.

[0192] Convert continuous E(t) and EC(t) into fuzzy linguistic variables:

[0193] Power deviation E(t): {Negative large (NB), negative medium (NM), negative small (NS), zero (ZO), positive small (PS), positive medium (PM), positive large (PB)};

[0194] Deviation change rate EC(t): {Negative fast (NB), negative medium (NM), negative slow (NS), zero (ZO), positive slow (PS), positive medium (PM), positive fast (PB)};

[0195] Example: When a sudden increase in steering load causes E(t) to exceed 20% of the rated power, E(t) belongs to "positive (PB)"; if EC(t) rises rapidly, it belongs to "positive fast (PB)".

[0196] The core logic for developing a fuzzy rule base based on expert experience is as follows:

[0197] When the operating conditions are stable (e.g., E(t)≈0, EC(t)≈0): decrease K p To avoid overshoot, increase K. i Eliminate steady-state error;

[0198] When demand surges (e.g., E(t) > 0 and EC(t) > 0): Increase K p Quick response, appropriately reduce K d Prevent high-frequency oscillation;

[0199] The fuzzy output is calculated using the Mamdani inference method and then converted to an accurate value using the centroid method.

[0200] K p =K p0 +u(ΔK p );

[0201] K i =K i0 +u(ΔK i );

[0202] K d =K d0 +u(ΔK d );

[0203] Among them, K p0 K i0 K d0 Here are the initial PID parameters, u(·) is the adjustment amount after defuzzification, and K... p K i K d These are the PID control parameters;

[0204] A PID control model is constructed, the PID adjustment parameters are input into the PID control model, the pump flow rate adjustment signal is output according to the PID control model, and the main pump displacement and motor speed are adjusted based on the pump flow rate adjustment signal.

[0205] It should be further explained that the specific process of inputting the PID adjustment parameters into the PID control model and outputting the pump flow adjustment signal according to the PID control model is as follows:

[0206]

[0207] Among them, Q cmd This is a pump flow rate adjustment signal;

[0208] The specific process of feedback adjustment of the main pump displacement and motor speed based on the pump flow rate adjustment signal is as follows:

[0209] The pump flow rate to be adjusted is determined based on the pump flow rate adjustment signal. The preset total oil supply flow rate is adjusted based on the pump flow rate to be adjusted to obtain the adjusted preset total oil supply flow rate. The adjusted preset total oil supply flow rate = preset total oil supply flow rate + pump flow rate to be adjusted. Based on the adjusted preset total oil supply flow rate, operating mode and efficiency comparison table, the displacement and motor speed corresponding to the maximum energy conversion efficiency of the main pump are obtained. The main pump is then adjusted based on the displacement and motor speed.

[0210] It should be further explained that, in the specific implementation process, the process of activating the fault redundancy mode includes:

[0211] Suspend the main pump operation, obtain the number of slave pumps to be activated based on the preset total oil supply flow and the maximum oil supply flow of the slave pumps, start each level of slave pumps in sequence according to the number of slave pumps to be activated and the activation order of several slave pumps, and set the personalized stagnation and shutdown thresholds for each level of slave pumps excluding the last level of slave pumps.

[0212] The formula for calculating the number of slave pumps to be activated, based on the preset total oil supply flow rate and the maximum oil supply flow rate of the slave pump, is as follows:

[0213]

[0214] The calculation process for setting the personalized lingering shutdown threshold for each slave pump, excluding the last-stage slave pump, is as follows:

[0215]

[0216] The preset total oil supply flow rate is compared with the individualized stagnation shut-off threshold of each slave pump, excluding the last stage slave pump;

[0217] If the preset total oil supply flow rate is less than the personalized stagnation shutdown threshold of a certain stage slave pump, then all slave pumps whose activation sequence follows that stage slave pump will be shut down.

[0218] The above embodiments are only used to illustrate the technical methods of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical methods of the present invention without departing from the spirit and scope of the technical methods of the present invention.

Claims

1. A multi-pump linkage special transport vehicle all-wheel steering hydraulic decoupling energy-saving control system, characterized in that, The system includes a control center, which is communicatively connected to a data acquisition module, a flexible control module, a parameter analysis module, a multi-pump linkage control module, and a main pump monitoring module. The data acquisition module is used to collect data on wheel angle, vehicle speed, road conditions, and pump status of special transport vehicles, and to mark the collection time and set the collection cycle. The flexible control module is used to dynamically adjust the operating mode of the special transport vehicle according to the wheel angle and vehicle speed; The parameter analysis module is used to obtain the steering gain and the preset total fuel supply flow of the pump group in the high-speed stable mode based on vehicle speed, and to obtain the target steering angle of each wheel and the preset total fuel supply flow of the pump group in the low-speed flexible mode based on wheel steering angle and road condition data. The multi-pump linkage control module is used to perform primary pump priority and slave pump stepwise activation operation based on the preset total oil supply flow of the pump set. Simultaneously, it dynamically sets personalized stagnation and shutdown thresholds for the primary pump and each stage of slave pumps, and performs stepwise shutdown operation of the slave pumps based on the preset total oil supply flow and personalized stagnation and shutdown thresholds, including: The pump set consists of a main pump and several slave pumps, obtaining the maximum oil supply flow rate of the main pump and the maximum oil supply flow rate of the several slave pumps; The preset safety margin is compared with the difference between the preset total oil supply flow and the maximum oil supply flow of the main pump and the safety margin. If the preset total oil supply flow is less than or equal to the difference between the maximum oil supply flow of the main pump and the safety margin, the output oil supply of the main pump is adjusted according to the preset total oil supply flow. When the preset total oil supply flow rate is greater than the difference between the maximum oil supply flow rate of the main pump and the safety margin, the number of slave pumps to be activated is obtained based on the preset total oil supply flow rate, the maximum oil supply flow rate of the slave pump, and the difference between the maximum oil supply flow rate of the main pump and the safety margin. The activation order of several slave pumps is preset, and each level of slave pumps is started sequentially according to the number of slave pumps to be activated and the activation order of several slave pumps. If the number of slave pumps to be activated is equal to one, then set the personalized stagnation shutdown threshold of the main pump. When the preset total oil supply flow is less than the personalized stagnation shutdown threshold, the slave pump will be shut down. If more than one slave pump needs to be activated, set the personalized stagnation and shutdown threshold for the main pump and all slave pumps except the last stage, and compare the preset total oil supply flow with the personalized stagnation and shutdown threshold for the main pump and all slave pumps except the last stage. If the preset total oil supply flow is less than the personalized stagnation and shutdown threshold of the main pump, all slave pumps are shut down. If the preset total oil supply flow is less than the personalized stagnation and shutdown threshold of a certain slave pump, all slave pumps whose activation sequence is after the certain slave pump are shut down. The process of dynamically setting personalized stagnation and shutdown thresholds for the main pump and each stage of slave pumps includes: Obtain the numerical time series corresponding to the preset total oil supply flow within the current acquisition period, perform statistical analysis on the numerical time series, and obtain the average fluctuating oil volume of the preset total oil supply flow. The personalized stagnation shut-off threshold of the main pump is obtained based on the maximum oil supply flow rate and average fluctuating oil volume of the main pump. The individualized retention shut-off thresholds of each slave pump are obtained based on the maximum oil supply flow of the main pump, the maximum oil supply flow of several slave pumps, and the average fluctuating oil volume. The main pump monitoring module is used to monitor the main pump in real time based on pump set status data, and to perform fuzzy PID feedback adjustment or activate fault redundancy operation on the main pump based on the monitoring results, including: The supply power is obtained by acquiring the inlet and outlet pressure difference of the main pump, the output oil supply, and the system efficiency coefficient based on the pump set status data; the demand power is obtained by acquiring the inlet and outlet pressure difference of the main pump, the preset total oil supply flow, and the system efficiency coefficient. The power deviation is obtained based on the power demand and the power supply. A power deviation threshold is preset. If the power deviation is greater than the power deviation threshold, the main pump is marked as an abnormal power state and the main pump is suspended. The number of slave pumps to be activated is obtained based on the preset total oil supply flow and the maximum oil supply flow of the slave pumps. The slave pumps at each level are started sequentially according to the number of slave pumps to be activated and the activation order of the slave pumps. A personalized stagnation and shutdown threshold is set for each level of slave pumps excluding the last level of slave pumps. The preset total oil supply flow rate is compared with the individualized stagnation shut-off threshold of each slave pump, excluding the last stage slave pump; If the preset total oil supply flow rate is less than the personalized stagnation shutdown threshold of a certain stage slave pump, then all slave pumps whose activation sequence is after the certain stage slave pump will be shut down. If the power deviation is less than or equal to the power deviation threshold, then the main pump is fuzzy PID feedback regulation.

2. The multi-pump linkage special transport vehicle all-wheel steering hydraulic decoupling energy-saving control system according to claim 1, characterized in that, The process by which the flexible control module dynamically adjusts the operating mode of the special transport vehicle based on wheel angle and vehicle speed includes: Preset trigger conditions for different operating modes, including high-speed stable mode and low-speed flexible mode, and the trigger conditions include threshold ranges for wheel angle and vehicle speed. Obtain the numerical time series of wheel angle and vehicle speed within the current collection period. Obtain the average value of wheel angle and vehicle speed based on the numerical time series. Compare the average value of wheel angle and vehicle speed with the trigger conditions corresponding to different operation modes to obtain the operation mode of the special transport vehicle.

3. The multi-pump linkage special transport vehicle all-wheel steering hydraulic decoupling energy-saving control system according to claim 2, characterized in that, The process by which the parameter analysis module obtains the steering gain and the preset total fuel supply flow of the pump unit in high-speed stable mode includes: When the special transport vehicle is in high-speed stable mode, a variable steering gain steering analysis is performed on the special transport vehicle based on the average vehicle speed to obtain the dynamically adjusted steering gain, and the maximum flow rate of the steering cylinder corresponding to each wheel of the special transport vehicle is obtained based on the average vehicle speed. Obtain the functional relationship between the average vehicle speed and the steering system flow demand coefficient, as well as the system efficiency coefficient. Based on the functional relationship between the average vehicle speed and the steering system flow demand coefficient, obtain the steering system flow demand coefficient corresponding to the current average vehicle speed. Based on the flow demand coefficient of the steering system and the maximum flow rate of the steering cylinder corresponding to each wheel, the actual flow demand of each steering cylinder at the current vehicle speed is obtained. Based on the actual flow demand of each steering cylinder and the system efficiency coefficient, the preset total oil supply flow rate of the pump set at the current moment is determined.

4. The multi-pump linkage special transport vehicle all-wheel steering hydraulic decoupling energy-saving control system according to claim 3, characterized in that, The parameter analysis module obtains the target steering angle of each wheel and the preset total oil supply flow of the pump unit in low-speed flexible mode, including the following processes: When the special transport vehicle is in low-speed flexible mode, the target turning angle of each wheel of the special transport vehicle is determined based on the road condition data and Ackerman steering geometry. The real-time steering angular velocity of each wheel is obtained based on the numerical time sequence corresponding to the wheel turning angle of each wheel. The preset total oil supply flow of the pump group at the current moment is determined based on the real-time steering angular velocity of each wheel, the displacement of the steering cylinder corresponding to each wheel and the system efficiency coefficient.

5. The multi-pump linkage special transport vehicle all-wheel steering hydraulic decoupling energy-saving control system according to claim 4, characterized in that, The energy-saving control module adjusts the main pump's output oil supply based on a preset total oil supply flow rate and maximum energy conversion efficiency. This process includes: An efficiency comparison table is pre-constructed, which includes the energy conversion efficiency corresponding to different displacements and motor speeds under different preset total oil supply flow rates and different operating modes. Based on the preset total oil supply flow, operating mode, and efficiency comparison table, obtain the displacement and motor speed corresponding to the maximum energy conversion efficiency of the main pump, and adjust the main pump according to the displacement and motor speed corresponding to the maximum energy conversion efficiency.

6. The multi-pump linkage special transport vehicle all-wheel steering hydraulic decoupling energy-saving control system according to claim 5, characterized in that, The process of fuzzy PID feedback regulation of the main pump includes: The power deviation at the current time and the previous time is obtained. The power deviation change rate is obtained based on the power deviation at the current time and the previous time. The power deviation at the current time and the power deviation change rate are used as evaluation indicators. The membership matrix and fuzzy rule base are predefined. The PID adjustment parameters corresponding to the evaluation indicators are obtained through fuzzy comprehensive evaluation. A PID control model is constructed, the PID adjustment parameters are input into the PID control model, and the pump flow adjustment signal is output. The main pump displacement and motor speed are adjusted based on the pump flow adjustment signal.

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