All-wheel steering hydraulic decoupling energy-saving control system for multi-pump linkage special transport vehicle

Abstract

An all-wheel steering hydraulic decoupling energy-saving control system for a multi-pump linkage special transport vehicle relates to the technical field of hydraulic control of special vehicles and comprises the following steps: acquiring wheel turning angles, vehicle speed, road condition data and pump set state data of the special transport vehicle; determining an operation mode of the special transport vehicle; the steering gain and the preset total oil supply flow of the pump set in the high-speed stable mode and the target turning angle of each wheel and the preset total oil supply flow of the pump set in the low-speed flexible mode are obtained; main pump priority and slave pump stepped activation operation is carried out according to the preset total oil supply flow of the pump set, meanwhile, personalized retention closing threshold values of the main pump and all stages of slave pumps are dynamically set, and slave pump stepped closing operation is carried out according to the preset total oil supply flow and the personalized retention closing threshold values; the main pump is monitored in real time according to the state data of the pump set, fuzzy PID feedback adjustment is conducted on the main pump or fault redundancy operation is started according to the monitoring result, the operation efficiency of the pump set is remarkably improved, and energy waste is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic control of special vehicles, in particular to an all-wheel steering hydraulic decoupling energy-saving control system for a multi-pump linkage special transport vehicle. Background Art

[0002] Chinese patent publication number CN119611499A discloses an all-wheel steering system and a straddle carrier, comprising: a main frame, a left travel mechanism, and a right travel mechanism; the left travel mechanism comprises 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 comprises 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 comprises a hydraulic steering gear and a left front hydraulic cylinder, a left rear hydraulic cylinder, a right front hydraulic cylinder, and a right rear hydraulic cylinder; the left front hydraulic cylinder is transmission-connected to the left front wheel frame, the left rear hydraulic cylinder is transmission-connected to the left rear wheel frame, the right front hydraulic cylinder is transmission-connected to the right front wheel frame, and the right rear hydraulic cylinder is transmission-connected to the right rear wheel frame; the hydraulic steering gear is used to supply and return oil to the left front hydraulic cylinder, the left rear hydraulic cylinder, the right front hydraulic cylinder, and the right rear hydraulic cylinder; a first mechanical synchronization mechanism and a second mechanical synchronization mechanism;

[0003] Chinese patent publication number CN119308912A discloses a hydraulic system and engineering machinery. The hydraulic system includes a hydraulic pump, a proportional reversing valve, a compensating valve, and a first relief valve. The oil outlet of the compensating valve is connected to the oil inlet of the proportional reversing valve, which in turn is connected to the oil outlet of the hydraulic pump. The oil inlet of the first relief valve can selectively connect to either the first oil port or the second oil port of the proportional reversing valve. The first chamber of the compensating valve and the oil inlet of the first relief valve are connected to the same oil port of the proportional reversing valve. The oil inlet of the proportional reversing 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 above-mentioned existing technologies involve multi-pump linkage and hydraulic decoupling, they have not achieved the deep integration of multi-mode steering, intelligent flow distribution and energy-saving control, and are difficult to meet the high-precision and low-energy consumption requirements under extreme working conditions. Summary of the Invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide an all-wheel steering hydraulic decoupling energy-saving control system for a multi-pump linkage special transport vehicle, comprising the following steps:

[0006] like Figure 1 As shown, the all-wheel steering hydraulic decoupling energy-saving control system of a multi-pump linkage special transport vehicle 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 the wheel angle, speed, road condition data and pump group status data of the special transport vehicle, mark the collection time, and set the collection cycle;

[0008] The flexible control module is used to dynamically adjust the operation 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 oil flow rate of the pump group in the high-speed stable mode based on the vehicle speed, and to obtain the target steering angle of each wheel and the preset total oil flow rate of the pump group in the low-speed flexible mode based on the wheel angle and road condition data;

[0010] The multi-pump linkage control module is used to perform master pump priority and slave pump step-by-step activation operations based on the preset total oil supply flow of the pump group. At the same time, it dynamically sets personalized retention and shutdown thresholds for the master pump and each level of slave pumps, and performs slave pump step-by-step shutdown operations based on the preset total oil supply flow and personalized retention and shutdown thresholds;

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

[0012] Furthermore, the process of the flexible control module dynamically adjusting the operation mode of the special transport vehicle according to the wheel angle and vehicle speed includes:

[0013] Preset trigger conditions corresponding to different operating modes, the operating modes including a high-speed stable mode and a low-speed flexible mode, and the trigger conditions including a threshold range of wheel angle and a threshold range of vehicle speed;

[0014] Obtain a numerical time series sequence corresponding to the wheel angle and the vehicle speed within the current acquisition period, obtain the average values ​​of the wheel angle and the vehicle speed based on the numerical time series sequence, compare the average values ​​of the wheel angle and the vehicle speed with the trigger conditions corresponding to different operating modes, obtain the threshold interval to which the average value of the wheel angle belongs and the threshold interval to which the average value of the vehicle speed belongs, and obtain the operating mode of the special transport vehicle based on the threshold interval to which the average value of the wheel angle belongs and the threshold interval to which the average value of the vehicle speed belongs.

[0015] Furthermore, the process of the parameter analysis module obtaining the steering gain and the preset total oil supply flow of the pump group in the 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 of the steering cylinder corresponding to each wheel of the special transport vehicle is obtained based on the average vehicle speed;

[0017] Obtaining a functional relationship between an average vehicle speed and a steering system flow demand coefficient and a system efficiency coefficient, and obtaining a steering system flow demand coefficient corresponding to the current average vehicle speed based on the functional relationship between the average vehicle speed and the steering system flow demand coefficient;

[0018] Based on the steering system flow demand coefficient and the maximum flow of the steering cylinder corresponding to each wheel, the actual flow demand of each steering cylinder at the average value of 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 of the pump group at the current moment is determined.

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

[0020]

[0021] Among them, K gain (v) is the steering gain after dynamic adjustment, K max is the maximum gain at low speed, K min is the minimum gain at high speed, v is the average speed, v ref is the gain attenuation characteristic vehicle speed;

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

[0023]

[0024] Among them, Q lim is the maximum flow of the steering cylinder, ω wheel_max (v) is the maximum wheel steering angular velocity allowed by the average value of the current vehicle speed, v cyl is the displacement of the steering cylinder, η v is the volumetric efficiency;

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

[0026]

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

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

[0029] Q i =k v ×Q lim-i ;

[0030] Among them, Q i represents the actual flow demand of the steering cylinder corresponding to wheel i at the average value of the current vehicle speed, Q lim-i Indicates the maximum flow of the steering cylinder corresponding to wheel i;

[0031] The calculation formula for obtaining the preset total oil supply flow of the pump group is:

[0032]

[0033] Among them, Q total is the preset total oil flow rate of the pump group, η is the system efficiency coefficient, and n represents the number of wheels on the special transport vehicle. The above formulas are dimensionless and numerically calculated. These formulas are derived from software simulations using extensive data collection to best approximate real-world conditions. The preset parameters in these formulas are set by those skilled in the art based on actual conditions or derived from extensive data simulations.

[0034] Furthermore, the process of the parameter analysis module obtaining the target turning angle of each wheel and the preset total oil supply flow of the pump group in the 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 Ackermann steering geometry according to the road condition data, the real-time steering angular velocity of each wheel is obtained according to the numerical time series corresponding to the wheel angle of each wheel, and 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 steering cylinder displacement corresponding to each wheel and the system efficiency coefficient.

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

[0037]

[0038] Among them, α inner-i represents the inner turning angle of wheel i, α outer-i represents the outer turning angle of wheel i, L is the wheelbase of the special transport vehicle, R is the turning radius obtained from the road condition data, and W is the wheelbase of the special transport vehicle;

[0039] The total oil flow rate Q 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. total :

[0040]

[0041] in, represents the real-time steering angular velocity of wheel i, v cyl-i 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 according to a preset total oil supply flow of the pump group, and performs a slave pump step-by-step shutdown operation according to the preset total oil supply flow and the personalized retention shutdown threshold, including:

[0043] The pump group consists of a master pump and several slave pumps. The maximum oil supply flow rate of the master pump and the maximum oil supply flow rates of the several slave pumps are obtained (the maximum oil supply flow rates of the several slave pumps are equal);

[0044] Preset safety margin, compare the preset total oil supply flow with the difference between 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, adjust the output oil supply of the main pump 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 master 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 master pump and the safety margin. The activation order of the slave pumps is preset, and the slave pumps of each level are started in sequence according to the number of slave pumps to be activated and the activation order of the slave pumps (the first slave pump started is marked as a first-level slave pump, the second slave pump started is marked as a second-level slave pump, and so on. The x-th slave pump started is marked as an x-level slave pump).

[0046] The formula for calculating the number of slave pumps to be activated is as follows:

[0047]

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

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

[0050] If the number of slave pumps to be activated is greater than one, the personalized retention shutdown thresholds of the master pump and each slave pump excluding the last slave pump (the last slave pump to be activated) are set, and the preset total oil supply flow rate is compared with the personalized retention shutdown thresholds of the master pump and each slave pump excluding the last slave pump;

[0051] If the preset total oil supply flow is less than the personalized retention shutdown threshold of the master pump, all slave pumps will be shut down. If the preset total oil supply flow is less than the personalized retention shutdown threshold of a certain level of slave pumps, the corresponding levels of slave pumps whose activation order is after the certain level of slave pump will be shut down.

[0052] Furthermore, the process of dynamically setting the personalized retention shutdown thresholds of the master pump and each level of slave pumps includes:

[0053] Obtain the numerical time series sequence corresponding to the preset total oil supply flow in the current collection period, perform statistical analysis on the numerical time series sequence, and obtain the average fluctuation 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 is as follows:

[0055]

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

[0057] Obtain the personalized retention shutdown threshold of the main pump based on the main pump's maximum oil supply flow and average fluctuating oil volume;

[0058] The personalized retention closing threshold value of each level of slave pumps is obtained according to the maximum oil supply flow rate of the master pump, the maximum oil supply flow rates of several slave pumps and the average fluctuating oil volume.

[0059] Furthermore, the calculation process for obtaining the personalized retention shutdown threshold of the main pump based on the maximum oil supply flow and the 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 Indicates the personalized retention shutoff threshold of the main pump;

[0062] The calculation process for obtaining the personalized retention shut-off thresholds for each level from the pump is:

[0063]

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

[0065] Furthermore, the process of the energy-saving control module for adjusting the output oil supply of the main pump with maximum energy conversion efficiency according to the preset total oil supply flow rate includes:

[0066] Pre-building an efficiency comparison table, the efficiency comparison table including energy conversion efficiencies corresponding to different displacements and motor speeds under different preset total oil flow rates and different operating modes;

[0067] According to the preset total oil supply flow, operation mode and efficiency comparison table, the displacement and motor speed corresponding to the maximum energy conversion efficiency of the main pump are obtained, and the main pump is adjusted 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 according to the pump group status data, and performs fuzzy PID feedback adjustment or starts fault redundancy operation on the main pump according to the monitoring results. The process includes:

[0069] The supplied power is obtained based on the inlet and outlet pressure difference of the main pump, the output oil supply volume and the system efficiency coefficient according to the pump group status data; the required power is obtained based on the inlet and outlet pressure difference of the main pump, the preset total oil supply flow rate and the system efficiency coefficient;

[0070] The formulas for obtaining the supplied power and the required power are:

[0071]

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

[0073] The power deviation is obtained based on the demand power and the supplied power, and a power deviation threshold is preset. If the power deviation is greater than the power deviation threshold, the main pump is marked as a power abnormality state and the fault redundancy operation is started. If the power deviation is less than or equal to the power deviation threshold, the main pump is fuzzy PID feedback adjusted.

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

[0075] Obtain the power deviation at the current moment and the previous moment, obtain the power deviation change rate based on the power deviation at the current moment and the previous moment, use the current power deviation and the power deviation change rate as evaluation indicators, pre-define the membership matrix and fuzzy rule base, and obtain the PID adjustment parameters corresponding to the evaluation indicators through fuzzy comprehensive evaluation;

[0076] The process of obtaining the PID adjustment 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 moment t, Δt is the acquisition period (s), E(t-Δt) is the power deviation at the previous moment, and E(t) is the power deviation at the current moment;

[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 middle (NM), negative slow (NS), zero (ZO), positive slow (PS), positive middle (PM), positive fast (PB)};

[0083] Example: When the steering load suddenly increases and E(t)>20% of rated power, E(t) belongs to "positive (PB)"; if EC(t) rises rapidly, it belongs to "positive (PB)";

[0084] A fuzzy rule base is developed based on expert experience. The core logic is as follows:

[0085] When the working condition is stable (such as E(t)≈0, EC(t)≈0): reduce K p To avoid overshoot, increase K i Eliminate static error;

[0086] When demand increases suddenly (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 converted to an exact 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 is the initial PID parameter, u(·) is the adjustment amount after defuzzification, K p , K i , K d is the PID adjustment parameter;

[0092] Construct a PID control model, input the PID adjustment parameters into the PID control model, output a pump flow adjustment signal according to the PID control model, and perform feedback adjustment on the main pump displacement and motor speed according to the pump flow adjustment signal.

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

[0094]

[0095] Among them, Q cmd It is the pump flow regulating signal;

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

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

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

[0099] Pause the operation of the master pump, 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 the slave pumps of each level in sequence according to the number of slave pumps to be activated and the activation order of the slave pumps, and set personalized retention and shutdown thresholds for each level of slave pumps excluding the last slave pump;

[0100] The calculation formula for obtaining 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 pump is:

[0101]

[0102] The calculation process for setting the personalized retention shutoff threshold for each slave pump excluding the last slave pump is:

[0103]

[0104] comparing a preset total oil supply flow rate with individualized retention shutoff thresholds of each slave pump stage excluding the last slave pump stage;

[0105] If the preset total oil supply flow rate is less than the personalized retention closing threshold of a certain level of slave pump, the corresponding levels of slave pumps that are activated in a sequence subsequent to the certain level of slave pump are closed.

[0106] Compared with the prior art, the present invention has the following beneficial effects:

[0107] 1. Precise operating mode switching: Through the flexible control module, the operating 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 controllability and adaptability.

[0108] 2. Optimized parameter analysis: The parameter analysis module can accurately determine the steering gain and the preset total oil flow of the pump group in high-speed stable mode, as well as the target steering angle of each wheel and the preset total oil 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 precise parameter support for vehicle steering and improves steering accuracy and stability.

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

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

[0111] 5. System integration and collaborative optimization: The control center realizes the integration and collaborative work of data acquisition, analysis, control and other functions through communication connections with various modules, enabling the entire system to be globally optimized according to the actual operating status of the vehicle, thereby improving the comprehensive performance of the all-wheel steering hydraulic system of special transport vehicles, including energy saving effects, steering accuracy, system stability and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0113] The following is a clear and complete description of the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0114] like Figure 1 As shown, the all-wheel steering hydraulic decoupling energy-saving control system of a multi-pump linkage special transport vehicle 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 the wheel angle, speed, road condition data and pump group status data of the special transport vehicle, mark the collection time, and set the collection cycle (usually 10 seconds);

[0116] The flexible control module is used to dynamically adjust the operation 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 oil flow rate of the pump group in the high-speed stable mode based on the vehicle speed, and to obtain the target steering angle of each wheel and the preset total oil flow rate of the pump group in the low-speed flexible mode based on the wheel angle and road condition data;

[0118] The multi-pump linkage control module is used to perform master pump priority and slave pump step-by-step activation operations based on the preset total oil supply flow of the pump group. At the same time, it dynamically sets personalized retention and shutdown thresholds for the master pump and each level of slave pumps, and performs slave pump step-by-step shutdown operations based on the preset total oil supply flow and personalized retention and shutdown thresholds;

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

[0120] It should be further explained that, in the specific implementation process, the process of the flexible control module dynamically adjusting the operation mode of the special transport vehicle according to the wheel angle and vehicle speed includes:

[0121] Preset trigger conditions corresponding to different operating modes, the operating modes including a high-speed stable mode and a low-speed flexible mode, and the trigger conditions including a threshold range of wheel angle and a threshold range of vehicle speed;

[0122] Obtain a numerical time series sequence corresponding to the wheel angle and the vehicle speed within the current acquisition period, obtain the average values ​​of the wheel angle and the vehicle speed based on the numerical time series sequence, compare the average values ​​of the wheel angle and the vehicle speed with the trigger conditions corresponding to different operating modes, obtain the threshold interval to which the average value of the wheel angle belongs and the threshold interval to which the average value of the vehicle speed belongs, and obtain the operating mode of the special transport vehicle based on the threshold interval to which the average value of the wheel angle belongs and the threshold interval to which the average value of the vehicle speed belongs.

[0123] Through multi-mode switching and variable parameter control, the steering system gain is reduced in high-speed stable mode, making the wheel angle and wheel steering angle have a nonlinear relationship, avoiding vehicle yaw fluctuations caused by small high-speed inputs. In low-speed flexible mode, the wheel steering angle is maximized (such as full-wheel ±45° deflection) to achieve the minimum turning radius, taking into account both high-speed stability and low-speed flexibility. At the same time, the steering response time is shortened by 30% compared with traditional systems.

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

[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 nonlinear relationship, avoiding vehicle yaw fluctuations 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, a simulator was used for experimental fitting to 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, which will cause flow loss, the system efficiency coefficient was introduced. The system efficiency coefficient is generally between 0.8 and 0.9, which reflects the proportion of the actual flow obtained by the hydraulic system from the pump group output to each steering cylinder). 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 was obtained;

[0127] Based on the steering system flow demand coefficient and the maximum flow of the steering cylinder corresponding to each wheel, the actual flow demand of each steering cylinder at the average value of 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 of the pump group at the current moment is determined.

[0128] It should be further explained that the process of obtaining the steering gain after dynamic adjustment by analyzing the variable steering gain of the special transport vehicle based on the average vehicle speed includes:

[0129]

[0130] Among them, K gain (v) is the steering gain after dynamic adjustment, K max is the maximum gain at low speed, K min is the minimum gain at high speed, v is the average speed, v ref is the gain attenuation characteristic vehicle speed;

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

[0132]

[0133] Among them, Q lim is the maximum flow of the steering cylinder, ω wheel_max (v) is the maximum wheel steering angular velocity allowed by the average value of the current vehicle speed, v cyl is the displacement of the steering cylinder, η v is the volumetric efficiency;

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

[0135]

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

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

[0138] Q i =k v ×Q lim-i ;

[0139] Among them, Q i represents the actual flow demand of the steering cylinder corresponding to wheel i at the average value of the current vehicle speed, Q lim-i Indicates the maximum flow of the steering cylinder corresponding to wheel i;

[0140] The calculation formula for obtaining the preset total oil supply flow of the pump group is:

[0141]

[0142] Among them, Q total is the preset total oil flow rate of the pump group, η is the system efficiency coefficient, and n represents the number of wheels on the special transport vehicle. The above formulas are dimensionless and numerically calculated. These formulas are derived from software simulations using extensive data collection to best approximate real-world conditions. The preset parameters in these formulas are set by those skilled in the art based on actual conditions or derived from extensive data simulations.

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

[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 Ackermann steering geometry according to the road condition data, and the wheel steering angle is maximized (such as full-wheel ±45° deflection) in the low-speed flexible mode to achieve the minimum turning radius. The real-time steering angular velocity of each wheel is obtained according to the numerical time series corresponding to the wheel angle of each wheel, and 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 steering cylinder displacement corresponding to each wheel, and the system efficiency coefficient.

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

[0146]

[0147] Among them, α inner-i represents the inner turning angle of wheel i, α outer-i represents the outer turning angle of wheel i, L is the wheelbase of the special transport vehicle, R is the turning radius obtained from the road condition data, and W is the wheelbase of the special transport vehicle;

[0148] The total oil flow rate Q 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. total :

[0149]

[0150] in, represents the real-time steering angular velocity of wheel i, v cyl-i 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 the master pump priority + slave pump step-by-step activation operation according to the preset total oil supply flow of the pump group, and performs the slave pump step-by-step shutdown operation according to the preset total oil supply flow and personalized retention shutdown threshold. The process includes:

[0152] The pump group consists of a master pump and several slave pumps. The master pump is an electro-hydraulic proportional variable pump whose displacement can be adjusted dynamically according to demand, while the slave pumps are fixed-displacement pumps. When the system needs flow, the master pump first provides the required flow, and the demand is met by adjusting its displacement and motor speed. If the maximum oil supply flow of the master pump is insufficient to meet the demand, the slave pumps are gradually started in a step-by-step manner, increasing the flow of one slave pump at a time until the total demand is met. This strategy can more accurately match flow demand, reduce energy waste, and reduce the number of starts and stops of slave pumps, extending their lifespan. Traditional multi-pump systems usually use fixed-displacement pumps, which means that the pump's output flow increase range is fixed and cannot be dynamically adjusted according to actual demand. When the system needs more flow, it may simply start more pumps, and when demand decreases, some pumps are stopped. This control method has the problem of uneven flow distribution because the output of each pump is fixed and cannot accurately match demand, resulting in energy waste. In addition, frequent starts and stops increase pump wear and reduce lifespan.

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

[0154] Preset safety margin, compare the preset total oil supply flow with the difference between 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, adjust the output oil supply of the main pump 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 master 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 master pump and the safety margin. The activation order of the slave pumps is preset, and the slave pumps of each level are started in sequence according to the number of slave pumps to be activated and the activation order of the slave pumps (the first slave pump started is marked as a first-level slave pump, the second slave pump started is marked as a second-level slave pump, and so on. The x-th slave pump started is marked as an x-level slave pump).

[0156] The formula for calculating the number of slave pumps to be activated is as follows:

[0157]

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

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

[0160] If the number of slave pumps to be activated is greater than one, the personalized retention shutdown thresholds of the master pump and each slave pump excluding the last slave pump (the last slave pump to be activated) are set, and the preset total oil supply flow rate is compared with the personalized retention shutdown thresholds of the master pump and each slave pump excluding the last slave pump;

[0161] If the preset total oil supply flow is less than the personalized retention shutdown threshold of the master pump, all slave pumps will be shut down. If the preset total oil supply flow is less than the personalized retention shutdown threshold of a certain level of slave pumps, the corresponding levels of slave pumps whose activation order is after the certain level of slave pump will be shut down.

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

[0163] Obtain the numerical time series sequence corresponding to the preset total oil supply flow in the current collection period, perform statistical analysis on the numerical time series sequence, and obtain the average fluctuation 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 is as follows:

[0165]

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

[0167] Obtain the personalized retention shutdown threshold of the main pump based on the main pump's maximum oil supply flow and average fluctuating oil volume;

[0168] The personalized retention closing threshold value of each level of slave pumps is obtained according to the maximum oil supply flow rate of the master pump, the maximum oil supply flow rates 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 of obtaining the personalized retention shutdown threshold of the main pump based on the maximum oil supply flow rate and the 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 Indicates the personalized retention shutoff threshold of the main pump;

[0172] The calculation process for obtaining the personalized retention shut-off thresholds for each level from the pump is:

[0173]

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

[0175] Set a personalized retention shutdown threshold to avoid frequent pump starts and stops and energy waste. For example, when the preset total oil supply flow exceeds the difference between the maximum oil supply flow of the master pump and the safety margin, the first slave pump is started. In order to avoid frequent starts and stops, the shutdown threshold should be lower than the maximum oil supply flow of the master pump. In this way, when the preset total oil supply flow drops, the slave pump will not be shut down immediately until the preset total oil volume is lower than the shutdown threshold, preventing switching back and forth. Compared with the traditional system (pump start and stop frequency ≥ 20 times / hour), the personalized retention shutdown threshold will reduce the start and stop frequency to ≤ 5 times / hour, extending the pump life by 25% and reducing energy consumption by 40%.

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

[0177] Since the main pump is an electro-hydraulic proportional variable pump, its displacement and motor speed can be adjusted dynamically according to demand, and its output oil supply is determined by the variable displacement and motor speed. The slave pump is a fixed displacement pump and its displacement is not variable. Therefore, the slave pump can only adjust the motor speed to change its oil supply, while the output oil supply of the main pump is determined by the fixed displacement and motor speed. Moreover, the efficiency of the conversion of the variable displacement and motor speed of the main pump in different situations is different. For example, when the speed is low at low speed and high flow, the displacement V is increased first (to avoid motor overspeed); when the speed is high at high speed and low flow, the speed n is reduced first (to avoid leakage caused by too small displacement); when the steering demand is small at high speed, the displacement V of the main pump is reduced. Even if n remains unchanged, the flow Q will decrease, thereby achieving energy saving. 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 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. The efficiency comparison table includes the energy conversion efficiency corresponding to different displacements and motor speeds under different preset total oil flow rates and different operating modes;

[0179] According to the preset total oil supply flow, operation mode and efficiency comparison table, the displacement and motor speed corresponding to the maximum energy conversion efficiency of the main pump are obtained, and the main pump is adjusted 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 according to the pump group status data, and performs fuzzy PID feedback adjustment or starts fault redundancy operation on the main pump according to the monitoring results. The process includes:

[0181] The supplied power is obtained based on the inlet and outlet pressure difference of the main pump, the output oil supply volume and the system efficiency coefficient according to the pump group status data; the required power is obtained based on the inlet and outlet pressure difference of the main pump, the preset total oil supply flow rate and the system efficiency coefficient;

[0182] The formulas for obtaining the supplied power and the required power are:

[0183]

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

[0185] The power deviation is obtained based on the demand power and the supplied power, and a power deviation threshold is preset. If the power deviation is greater than the power deviation threshold, the main pump is marked as a power abnormality state and the fault redundancy operation is started. If the power deviation is less than or equal to the power deviation threshold, the main pump is fuzzy PID feedback adjusted.

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

[0187] Obtain the power deviation at the current moment and the previous moment, obtain the power deviation change rate based on the power deviation at the current moment and the previous moment, use the current power deviation and the power deviation change rate as evaluation indicators, pre-define the membership matrix and fuzzy rule base, and obtain the PID adjustment parameters corresponding to the evaluation indicators through fuzzy comprehensive evaluation;

[0188] The process of obtaining the PID adjustment 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 moment t, Δt is the acquisition period (s), E(t-Δt) is the power deviation at the previous moment, and E(t) is the power deviation at the current moment;

[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 middle (NM), negative slow (NS), zero (ZO), positive slow (PS), positive middle (PM), positive fast (PB)};

[0195] Example: When the steering load suddenly increases and E(t)>20% of rated power, E(t) belongs to "positive (PB)"; if EC(t) rises rapidly, it belongs to "positive (PB)";

[0196] A fuzzy rule base is developed based on expert experience. The core logic is as follows:

[0197] When the working condition is stable (such as E(t)≈0, EC(t)≈0): reduce K p To avoid overshoot, increase K i Eliminate static error;

[0198] When demand increases suddenly (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 converted to an exact 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 is the initial PID parameter, u(·) is the adjustment amount after defuzzification, K p , K i , K d is the PID adjustment parameter;

[0204] Construct a PID control model, input the PID adjustment parameters into the PID control model, output a pump flow adjustment signal according to the PID control model, and perform feedback adjustment on the main pump displacement and motor speed according to the pump flow 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 It is the pump flow regulating signal;

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

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

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

[0211] Pause the operation of the master pump, 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 the slave pumps of each level in sequence according to the number of slave pumps to be activated and the activation order of the slave pumps, and set personalized retention and shutdown thresholds for each level of slave pumps excluding the last slave pump;

[0212] The calculation formula for obtaining 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 pump is:

[0213]

[0214] The calculation process for setting the personalized retention shutoff threshold for each slave pump excluding the last slave pump is:

[0215]

[0216] comparing a preset total oil supply flow rate with individualized retention shutoff thresholds of each slave pump stage excluding the last slave pump stage;

[0217] If the preset total oil supply flow rate is less than the personalized retention closing threshold of a certain level of slave pump, the corresponding levels of slave pumps that are activated in a sequence subsequent to the certain level of slave pump are closed.

[0218] The above embodiments are only used to illustrate the technical method of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. The all-wheel steering hydraulic decoupling energy-saving control system of a multi-pump linkage special transport vehicle is characterized by: It 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 the wheel angle, speed, road condition data and pump group status data of the special transport vehicle, mark the collection time, and set the collection cycle; The flexible control module is used to dynamically adjust the operation 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 oil flow rate of the pump group in the high-speed stable mode based on the vehicle speed, and to obtain the target steering angle of each wheel and the preset total oil flow rate of the pump group in the low-speed flexible mode based on the wheel angle and road condition data; The multi-pump linkage control module is used to perform master pump priority and slave pump step-by-step activation operations based on the preset total oil supply flow of the pump group. At the same time, it dynamically sets personalized retention and shutdown thresholds for the master pump and each level of slave pumps, and performs slave pump step-by-step shutdown operations based on the preset total oil supply flow and personalized retention and shutdown thresholds; The main pump monitoring module is used to monitor the main pump in real time according to the pump group status data, and perform fuzzy PID feedback adjustment on the main pump or start fault redundancy operation according to the monitoring results.

2. The all-wheel steering hydraulic decoupling energy-saving control system for a multi-pump linkage special transport vehicle according to claim 1 is characterized in that: The process by which the flexible control module dynamically adjusts the operation mode of the special transport vehicle according to the wheel angle and vehicle speed includes: Preset trigger conditions corresponding to different operating modes, the operating modes including a high-speed stable mode and a low-speed flexible mode, and the trigger conditions including a threshold range of a wheel angle and a threshold range of a vehicle speed; Obtain the numerical time series sequence corresponding to the wheel angle and vehicle speed in the current acquisition cycle, obtain the average values ​​of the wheel angle and vehicle speed based on the numerical time series sequence, compare the average values ​​of the wheel angle and vehicle speed with the trigger conditions corresponding to different operating modes, and obtain the operating mode of the special transport vehicle.

3. The all-wheel steering hydraulic decoupling energy-saving control system for a multi-pump linkage special transport vehicle according to claim 2 is characterized in that: The process of the parameter analysis module obtaining the steering gain and the preset total oil supply flow of the pump group in the 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 of the steering cylinder corresponding to each wheel of the special transport vehicle is obtained based on the average vehicle speed; Obtaining a functional relationship between an average vehicle speed and a steering system flow demand coefficient and a system efficiency coefficient, and obtaining a steering system flow demand coefficient corresponding to the current average vehicle speed based on the functional relationship between the average vehicle speed and the steering system flow demand coefficient; Based on the steering system flow demand coefficient and the maximum flow of the steering cylinder corresponding to each wheel, the actual flow demand of each steering cylinder at the average value of 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 of the pump group at the current moment is determined.

4. The all-wheel steering hydraulic decoupling energy-saving control system for a multi-pump linkage special transport vehicle according to claim 3 is characterized in that: 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 group in the low-speed flexible mode includes: 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 Ackermann steering geometry according to the road condition data, the real-time steering angular velocity of each wheel is obtained according to the numerical time series corresponding to the wheel angle of each wheel, and 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 steering cylinder displacement corresponding to each wheel and the system efficiency coefficient.

5. The all-wheel steering hydraulic decoupling energy-saving control system for a multi-pump linkage special transport vehicle according to claim 4 is characterized in that: The multi-pump linkage control module performs master pump priority + slave pump step-by-step activation operations based on the preset total oil supply flow of the pump group. The process of performing slave pump step-by-step shutdown operations based on the preset total oil supply flow and personalized retention shutdown threshold includes: The pump group consists of a master pump and several slave pumps, and the maximum oil supply flow rate of the master pump and the maximum oil supply flow rate of the several slave pumps are obtained; Preset safety margin, compare the preset total oil supply flow with the difference between 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, adjust the output oil supply of the main pump 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 master 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 pumps, and the difference between the maximum oil supply flow rate of the master pump and the safety margin. The activation order of the slave pumps is preset, and the slave pumps of each level are started in sequence according to the number of slave pumps to be activated and the activation order of the slave pumps. If the number of slave pumps to be activated is equal to one, set the personalized retention shutdown threshold of the master pump. When the preset total oil supply flow is less than the personalized retention shutdown threshold, shut down the slave pump; If the number of slave pumps to be activated is greater than one, the personalized retention shutdown thresholds of the master pump and each slave pump excluding the last slave pump are set, and the preset total oil supply flow rate is compared with the personalized retention shutdown thresholds of the master pump and each slave pump excluding the last slave pump; If the preset total oil supply flow is less than the personalized retention shutdown threshold of the master pump, all slave pumps will be shut down. If the preset total oil supply flow is less than the personalized retention shutdown threshold of a certain level of slave pumps, the corresponding levels of slave pumps whose activation order is after the certain level of slave pump will be shut down.

6. The all-wheel steering hydraulic decoupling energy-saving control system for a multi-pump linkage special transport vehicle according to claim 5 is characterized in that: The process of dynamically setting personalized retention shutdown thresholds for the master pump and each level of slave pumps includes: Obtain the numerical time series sequence corresponding to the preset total oil supply flow in the current collection period, perform statistical analysis on the numerical time series sequence, and obtain the average fluctuation oil volume of the preset total oil supply flow; Obtain the personalized retention shutdown threshold of the main pump based on the main pump's maximum oil supply flow and average fluctuating oil volume; The personalized retention closing threshold value of each level of slave pumps is obtained according to the maximum oil supply flow rate of the master pump, the maximum oil supply flow rates of several slave pumps and the average fluctuating oil volume.

7. The all-wheel steering hydraulic decoupling energy-saving control system for a multi-pump linkage special transport vehicle according to claim 6 is characterized in that: The energy-saving control module is used to adjust the output oil supply of the main pump with maximum energy conversion efficiency according to the preset total oil supply flow rate, including the following process: Pre-building an efficiency comparison table, the efficiency comparison table including energy conversion efficiencies corresponding to different displacements and motor speeds under different preset total oil flow rates and different operating modes; According to the preset total oil supply flow, operation mode and efficiency comparison table, the displacement and motor speed corresponding to the maximum energy conversion efficiency of the main pump are obtained, and the main pump is adjusted according to the displacement and motor speed corresponding to the maximum energy conversion efficiency.

8. The all-wheel steering hydraulic decoupling energy-saving control system for a multi-pump linkage special transport vehicle according to claim 7 is characterized in that: The main pump monitoring module monitors the main pump in real time based on the pump group status data. The process of performing fuzzy PID feedback adjustment or starting fault redundancy operation on the main pump based on the monitoring results includes: The supplied power is obtained based on the inlet and outlet pressure difference of the main pump, the output oil supply volume and the system efficiency coefficient according to the pump group status data; the required power is obtained based on the inlet and outlet pressure difference of the main pump, the preset total oil supply flow rate and the system efficiency coefficient; The power deviation is obtained based on the demand power and the supplied power, and a power deviation threshold is preset. If the power deviation is greater than the power deviation threshold, the main pump is marked as a power abnormality state and the fault redundancy operation is started. If the power deviation is less than or equal to the power deviation threshold, the main pump is fuzzy PID feedback adjusted.

9. The all-wheel steering hydraulic decoupling energy-saving control system for a multi-pump linkage special transport vehicle according to claim 8 is characterized in that: The process of fuzzy PID feedback regulation of the main pump includes: Obtain the power deviation at the current moment and the previous moment, obtain the power deviation change rate based on the power deviation at the current moment and the previous moment, use the current power deviation and the power deviation change rate as evaluation indicators, pre-define the membership matrix and fuzzy rule base, and obtain the PID adjustment parameters corresponding to the evaluation indicators through fuzzy comprehensive evaluation; Construct a PID control model, input the PID adjustment parameters into the PID control model, output the pump flow adjustment signal, and perform feedback adjustment on the main pump displacement and motor speed according to the pump flow adjustment signal.

10. The all-wheel steering hydraulic decoupling energy-saving control system for a multi-pump linkage special transport vehicle according to claim 9, characterized in that: The process of starting the failover mode includes: Pause the operation of the master pump, 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 the slave pumps of each level in sequence according to the number of slave pumps to be activated and the activation order of the slave pumps, and set personalized retention and shutdown thresholds for each level of slave pumps excluding the last slave pump; comparing a preset total oil supply flow rate with individualized retention shutoff thresholds of each slave pump stage excluding the last slave pump stage; If the preset total oil supply flow rate is less than the personalized retention closing threshold of a certain level of slave pump, the corresponding levels of slave pumps that are activated in a sequence subsequent to the certain level of slave pump are closed.

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