Dynamic compensation calibration method for pump-valve cooperative control hydraulic system of excavator

Abstract

The invention provides a dynamic compensation calibration method for a pump-valve cooperative control hydraulic system of an excavator, which relates to the field of engineering machinery and comprises the following steps of: calibrating a variable pump under an impedance working condition, and compensating the deviation between the output flow of the variable pump and the output flow curve of the variable pump to the input current of a first proportional pressure reducing valve; the output flow of the compensated variable pump is obtained; the multi-way valve is calibrated on the basis of the calibrated variable pump under the overrunning working condition, the deviation between the valve element displacement and a multi-way valve element displacement curve is compensated to the input current of the second proportional pressure reducing valve, the compensated valve element displacement of the multi-way valve is obtained, and the calibrated variable pump and the multi-way valve are input into a control hydraulic system; according to the method, the excavator executes specific continuous actions to achieve calibration of the pump valve of the hydraulic system, staged dynamic calibration and real-time data iteration correction are conducted on the pump valve of the hydraulic excavator under different load working conditions, nonlinearity and uncertainty of the hydraulic system are dynamically compensated, and accurate calibration of the pump valve of the hydraulic excavator under the complex working conditions is achieved.

Description

Technical Field

[0001] The present invention relates to the field of construction machinery, and particularly to a dynamic compensation calibration method for an excavator pump-valve coordinated control hydraulic system. Background Art

[0002] As a construction machinery with high power and complex motion control, excavators are widely used in large-scale projects such as infrastructure construction and road building. With the growth of municipal engineering and road construction projects, China has become the world's largest excavator market, and is gradually becoming the manufacturing center of the world's excavator industry and integrating into the global supply chain system. With the development of intelligentization and electrification, the requirements for the control accuracy of excavators are also increasing day by day. To realize intelligent auxiliary functions such as trajectory planning, electronic fence, and dynamic weighing, as the core components of the hydraulic system, hydraulic components need to meet higher control accuracy requirements.

[0003] At present, the excavator hydraulic system faces many challenges during operation. The hydraulic system itself has significant non-linear characteristics. For example, the flow rate of a variable pump is affected by factors such as volumetric efficiency and mechanical efficiency, and there may be a complex non-linear relationship between the flow rate of a proportional relief valve and a multi-way valve and the input current. In addition, the hydraulic system is also affected by factors such as friction coefficient, load change, and oil leakage. These uncertainties will cause fluctuations in the performance of the hydraulic system. Especially in complex working conditions such as high impact and variable load, the stability and accuracy of the hydraulic system are further tested.

[0004] To ensure the stability and accuracy of the hydraulic system under various working conditions, the calibration of variable pumps and multi-way valves is crucial. Calibration can dynamically compensate for the non-linearity and uncertainty of the hydraulic system, compensate for component matching errors, and ensure precise control. The existing calibration of the excavator pump-valve hydraulic system cannot comprehensively simulate the actual working conditions, resulting in a large deviation between the calibration results and the actual performance. It is necessary to propose a dynamic compensation calibration method for an excavator pump-valve coordinated control hydraulic system. Summary of the Invention

[0005] In order to solve the above deficiencies of the prior art, the purpose of the present invention is to provide a dynamic compensation calibration method for an excavator pump-valve coordinated control hydraulic system. By performing staged dynamic calibration and real-time data iterative correction on the hydraulic excavator pump-valve under different load conditions, the non-linearity and uncertainty of the hydraulic system are dynamically compensated, the matching errors of the variable pump, multi-way valve, and proportional relief valve are compensated, and precise calibration of the pump-valve of the hydraulic excavator under complex operating conditions is achieved.

[0006] The present invention provides a dynamic compensation calibration method for an excavator pump-valve coordinated control hydraulic system, which includes:

[0007] Based on the bench test, the input current curve of the first proportional pressure reducing valve and the output flow curve of the variable pump, as well as the input current curve of the second proportional pressure reducing valve and the spool displacement curve of the multi-way valve, are obtained;

[0008] Calibrate the variable pump under the impedance condition:

[0009] Calibrate the variable pump after calibration through the slewing action of the excavator. Based on the output flow curve of the variable pump, use n pump calibration points to calibrate the variable pump after calibration. Set the command speed and fixed displacement of the hydraulic slewing motor to obtain the theoretical flow rate Q of the variable pump 泵头理论 , According to the output flow curve of the variable pump, input the input current of the corresponding first proportional pressure reducing valve to control the variable pump oil supply system;

[0010] Based on the actual speed of the slewing motor, obtain the actual output flow rate Q of the variable pump 泵头实际 , Through the pump calibration points at each speed of the slewing motor, compensate the deviation between the output flow rate of the variable pump and the output flow curve of the variable pump to the input current of the first proportional pressure reducing valve to obtain the compensated output flow rate of the variable pump after calibration;

[0011] Based on the variable pump after calibration, calibrate the variable pump before calibration through the single action of the boom lifting. The calibration of the variable pump before calibration is the same as that of the variable pump after calibration;

[0012] Based on the calibrated variable pump, calibrate the multi-way valve under the overrun condition:

[0013] Set the spool displacement X1 of the multi-way valve in the bucket rod connection. According to the spool displacement curve of the multi-way valve, obtain the input current of the second proportional pressure reducing valve, and then control the multi-way valve. According to the actual flow rate of the rodless chamber and the output flow rate of the variable pump, obtain the oil return regeneration flow rate. Through the oil return flow rate of the rod chamber of the bucket rod hydraulic cylinder and the oil return regeneration flow rate, obtain the flow rate through the oil return valve of the multi-way valve in the bucket rod connection;

[0014] Based on the flow rate-pressure continuity equation, obtain the actual spool displacement of the multi-way valve through the actual flow rate of the oil return valve. By analyzing the valve calibration points at each spool displacement, compensate the deviation between the spool displacement and the spool displacement curve of the multi-way valve to the input current of the second proportional pressure reducing valve to obtain the compensated spool displacement of the multi-way valve;

[0015] Input the calibrated variable pump and multi-way valve into the control hydraulic system.

[0016] Preferably, the theoretical flow rate Q of the variable pump 泵头理论 :

[0017]

[0018] In the formula, D m is the displacement of the slewing motor, V m is the total volume of the oil inlet chamber of the slewing motor and the connecting pipeline, P m,iis the pressure of the inlet oil chamber of the slewing motor, when the hydraulic motor is moving at a constant speed β is the volume elasticity model of the oil, N 1,i is the commanded speed of the hydraulic slewing motor, i is the number of repeated experiments, ΔQ 其他 is the flow loss of the unknown interference term.

[0019] Preferably, the actual output flow rate Q of the variable pump 泵头实际 :

[0020]

[0021] In the formula, Q 容积效率损失 , Q 机械效率损失 are the output flow losses of the hydraulic pump caused by the volumetric efficiency and mechanical efficiency, N 2,i is the actual speed of the hydraulic slewing motor, and the pump calibration point is (I b,1 , Q 泵头实际，1 ), (I b,2 , Q 泵头实际，2 ), …, (I b,n , Q 泵头实际，n ), (I b,1 , Q 泵头理论，1 ), (I b,2 , Q 泵头理论，2 ), …, (I b,n , Q 泵头理论，n ).

[0022] Preferably, the output flow rate Q of the compensated post-variable pump 泵头流量 :

[0023]

[0024] In the formula, f b (I b ) is the output flow rate of the variable pump corresponding to the current value I b on the variable pump output flow curve.

[0025] Preferably, the oil return regeneration flow rate Q 泵头流量 :

[0026] Q 回油再生 = v 3,i × A 无杆腔 - Q 变量泵

[0027] In the formula, v 3,i is the moving speed of the hydraulic cylinder in the i-th experiment, A 无杆腔 is the pressure-bearing area of the rodless chamber of the hydraulic cylinder, Q 变量泵 is the output flow rate of the variable pump.

[0028] Preferably, the flow rate Q through the oil return valve of the bucket link multi-way valve 回油阀 :

[0029] Q 回油阀 = v 3,i × A 有杆腔 -(v 3,i × A 无杆腔 - Q 变量泵 ) = v 3,i ×(A 有杆腔 - A 无杆腔 ) + Q 变量泵

[0030] In the formula, Q 变量泵 is a known term, A 无杆腔 is the pressure-bearing area of the rodless cavity, A 有杆腔 is the pressure-bearing area of the rod cavity, P 无杆腔 is the pressure of the rodless cavity, P 有杆腔 is the pressure of the rod cavity, V 无杆腔 is the total volume of the rodless cavity and the connecting pipeline, V 有杆腔 is the total volume of the rod cavity and the connecting pipeline.

[0031] Preferably, the actual displacement X of the multi-way valve spool 实际 :

[0032]

[0033] In the formula, C d is the flow coefficient, A(X 实际 ) is the flow area of the oil return valve port of the multi-way valve when the spool displacement is X 实际 , ΔP is the pressure difference across the oil return valve port of the multi-way valve, ρ is the oil density, A -1 (X 实际 ) is the inverse function of A(X 实际 ).

[0034] Preferably, the displacement X of the multi-way valve spool after compensation 阀开度 :

[0035]

[0036] In the formula, f f (I f ) is the variable pump output flow corresponding to the spool displacement curve of the multi-way valve at the current value I f .

[0037] Preferably, the actual flows Q 无杆腔 , Q 有杆腔 of the two chambers are obtained based on the actual moving speed of the boom cylinder

[0038]

[0039] In the formula, under the condition of uniform motion of the hydraulic cylinder

[0040] Compared with the prior art, the beneficial effects of the present invention are embodied in that: the dynamic compensation calibration method for the pump-valve coordinated control hydraulic system of the excavator of the present invention performs phased dynamic calibration and real-time data iterative correction on the pump and valve of the hydraulic excavator under different load conditions, dynamically compensates for the nonlinearity and uncertainty of the hydraulic system, compensates for the component matching error, and realizes the precise calibration of the pump and valve of the hydraulic excavator under complex operating conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a flowchart of the dynamic compensation calibration method for the pump-valve coordinated control hydraulic system of the excavator of the present invention;

[0042] Figure 2 is a schematic diagram of the hydraulic control system of the dynamic compensation calibration method for the pump-valve coordinated control hydraulic system of the excavator of the present invention;

[0043] Figure 3 is a schematic diagram of the pump and valve calibration of the hydraulic excavator in the dynamic compensation calibration method for the pump-valve coordinated control hydraulic system of the present invention;

[0044] Figure 4 is an operation flowchart of the dynamic compensation calibration method of the hydraulic system in the present invention;

[0045] Figure 5 is an operation flowchart of the dynamic compensation calibration of the variable pump in the present invention;

[0046] Figure 6 is an operation flowchart of the dynamic compensation calibration of the multi-way valve in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] Hereinafter, the embodiments of the present invention will be described with reference to the drawings.

[0048] The dynamic compensation calibration method for the pump-valve coordinated control hydraulic system of the excavator of the present invention, as Figures 1 to 6 shown, includes the following steps:

[0049] S1. Obtain the first proportional relief valve input current and variable pump output flow curve and the second proportional relief valve input current and multi-way valve spool displacement curve based on bench test.

[0050] S2. Calibrate the variable pump under the impedance condition: Under the impedance condition, the load force and the moving speed are in the opposite direction, and its sub-steps include:

[0051] S21. Calibrate the post-variable pump through the swing motion of the excavator. Specify the initial pose of the excavator as the boom extended, the stick fully retracted, the bucket fully retracted, and the swing angle is defined as 0°. The end pose is specified as the boom extended, the stick fully retracted, the bucket fully retracted, and rotated clockwise to a swing angle of 180°. Based on the output flow curve of the variable pump, calibrate the post-variable pump with n pump calibration points. Starting from the initial pose, rotate to the end pose at a constant speed of 5s, 8s, …, (3n + 2)s respectively.

[0052] The commanded speed of the hydraulic swing motor is:

[0053] N 1,i = θt 1,i

[0054] In the formula, N 1,i = [N 1,1 , N 1,2 , L, N 1,n is the rotational speed of the swing hydraulic motor, θ is the preset rotation angle of 180° of the excavator swing hydraulic motor, and t 1,i = [t 1,1 , t 1,2 , L, t 1,n is the preset swing motion time.

[0055] S22. During the swing of the excavator, control the inlet and outlet valve ports of the swing combined multi-way valve to be fully open. Ignoring the throttling losses of pipelines, valve ports, etc. and factors such as hydraulic motor leakage, since the influence of oil compression on flow during uniform motion is negligible, the flow output by the variable pump all enters the hydraulic motor. According to the time command of the excavator swing and the rotation angle of the swing hydraulic motor, obtain the rotational speed of the hydraulic motor, set the commanded speed and fixed displacement of the hydraulic swing motor, and obtain the theoretical flow rate Q of the variable pump 泵头理论 :

[0056]

[0057] In the formula, D m is the displacement of the swing motor, V m is the total volume of the inlet chamber of the swing motor and the connecting pipeline, P m,i is the pressure of the inlet chamber of the swing motor. Under the condition of uniform motion of the hydraulic motor β is the oil volume elasticity model, N 1,i is the commanded speed of the hydraulic swing motor, i is the number of repeated experiments, and ΔQ 其他 is the flow loss of the unknown interference term.

[0058] Input the input current of the corresponding first proportional relief valve according to the output flow curve of the variable pump to control the variable pump oil supply system;

[0059] S3. Considering the strong non-linear characteristics of the hydraulic system, after ignoring the throttling losses such as pipelines and valve ports, as well as factors such as pipeline and hydraulic motor leakage, the variable pump is affected by factors such as volumetric efficiency, mechanical efficiency, and flow compression. Since the influence of oil compression on flow during uniform motion is negligible, based on the actual rotational speed of the rotary motor, the actual output flow Q of the variable pump is obtained. 泵头实际 :

[0060]

[0061] In the formula, Q 容积效率损失 , Q 机械效率损失 are the output flow losses of the hydraulic pump caused by volumetric efficiency and mechanical efficiency, N 2,i is the actual rotational speed of the hydraulic rotary motor. The pump calibration points are (I b,1 , Q 泵头实际，1 ), (I b,2 , Q 泵头实际，2 ), …, (I b,n , Q 泵头实际，n ), (I b,1 , Q 泵头理论，1 ), (I b,2 , Q 泵头理论，2 ), …, (I b,n , Q 泵头理论，n );

[0062] Based on the uniform motion condition, ignoring secondary factors such as compression and leakage, the strong non-linear hydraulic system is modeled as the relationship between motor speed and flow. Clearly quantify the coupling relationship between pump source flow, loss flow, and hydraulic motor input flow, providing a theoretical basis for accurately calculating the flow entering the hydraulic rotary motor. This method is based on the calculation result of the real-time inlet flow of the rotary motor, dynamically adjusting the control command of the variable pump displacement, so that the hydraulic system can still maintain the calibration accuracy under pressure fluctuations or load changes.

[0063] Through the pump calibration points at each rotational speed of the rotary motor, the deviation between the variable pump output flow and the variable pump output flow curve is compensated to the input current of the first proportional relief valve, and the compensated variable pump output flow Q 泵头流量 ;

[0064]

[0065] In the formula, f b (I b ) is the variable pump output flow corresponding to the current value I b on the variable pump output flow curve.

[0066] Based on the calibrated variable pump, the front variable pump is calibrated by the single action of the boom lifting, and the calibration of the front variable pump is the same as that of the rear variable pump;

[0067] The calibration of the descent curve is based on the known hysteresis width of the input current and output displacement curve of the proportional pressure reducing valve and the variable pump in the bench test. The corresponding descent curve is obtained by adding or subtracting the hysteresis width from the calibrated rising curve.

[0068] S4. Calibrate the multi-way valve under the overrunning condition based on the calibrated variable displacement pump. Under the overrunning condition, the load force and the movement speed are in the same direction. The excavator's overrunning single actions include boom lowering, arm digging, and bucket digging, which are controlled by the boom-linked multi-way valve, the arm-linked multi-way valve, and the bucket-linked multi-way valve, respectively. Taking the arm digging single action as an example, the calibration method of the arm-linked multi-way valve is the same as that of the boom-linked and bucket-linked multi-way valves. The sub-steps include:

[0069] S41. Under the overtaking condition, the excavator boom is fully extended and the bucket is fully extended and remains stationary, and the dipper arm performs digging action. The system throttles and adjusts the speed through the return oil valve port, and sets the valve core displacement X1 of the dipper arm multi-way valve to (0.3, 0.4, ..., (n+0.2)) mm. The input current of the second proportional pressure reducing valve is obtained according to the valve core displacement curve of the multi-way valve, and then the multi-way valve is controlled.

[0070] Based on the input current and output valve core displacement test curves of the proportional pressure reducing valve and the multi-way valve to be calibrated, the theoretical current signal I of the proportional pressure reducing valve corresponding to the valve core displacement instruction of each boom-linked multi-way valve is obtained by the plotting method. f,i =[I f,1 ,I f,2 ,L,I f,n ],

[0071] X 阀开度 =f f,台架 (I f,i ).

[0072] The opening of the multi-way valve is adjusted by the proportional pressure reducing valve theoretical current control signal, and the variable pump is given a fixed flow. At this time, the hydraulic pump has been calibrated and the bucket arm is extended from the fully retracted state to the maximum stroke at a uniform speed to perform the bucket arm excavation action. The actual extension displacement of the bucket arm hydraulic cylinder is measured by the displacement sensor, and the actual movement time t is recorded according to the actual movement time. 3,i , get the actual movement speed of the bucket hydraulic cylinder:

[0073] v 3,i =X d / t 3,i

[0074] Where, v 3,i is the moving speed of the hydraulic cylinder in the i-th experiment, t 3,i =[t 3,1 ,t 3,2 ,L,t 3,n ] is the actual running time, X dis the actual extended displacement of the arm cylinder.

[0075] S42. Considering that the arm cylinder is in the oil return and regeneration working condition at this time, the flow rate of the rodless chamber is the sum of the flow rate provided by the pump head and the oil return and regeneration flow rate, and the flow rate of the rod chamber is the synthesis of the oil return and regeneration flow rate and the flow rate through the oil return valve port of the arm joint multi-way valve. At the same time, considering the strong non-linear characteristics of the hydraulic system, the flow rate in the system is affected by factors such as compression, pipeline loss, and leakage. Since the influence of oil compression on the flow rate during uniform motion is negligible, ignoring the throttling losses such as pipelines and valve ports and the leakage of the hydraulic cylinder, based on the actual moving speed of the arm cylinder, the actual flow rates Q 无杆腔 , Q 有杆腔 :

[0076]

[0077] In the formula, under the condition of uniform motion of the hydraulic cylinder

[0078] Based on the uniform motion working condition, ignoring secondary factors such as compression and leakage, the strong non-linear hydraulic system is modeled as a linear relationship between speed and flow rate, making the real-time flow rate distribution calculation feasible. Clearly quantify the coupling relationship between the pump source flow rate, regeneration flow rate and oil return valve port flow rate, reveal the energy recovery mechanism under the regeneration working condition, and provide a theoretical basis for accurately calculating the flow rate through the oil return valve port. This method is based on the solution result of the real-time oil return valve port flow rate, and dynamically adjusts the control command of the valve port opening, so that the hydraulic system can still maintain the calibration accuracy under pressure fluctuations or load changes.

[0079] The oil return and regeneration flow rate is obtained according to the actual flow rate of the rodless chamber and the output flow rate of the variable pump:

[0080] Q 回油再生 = v 3,i × A 无杆腔 - Q 变量泵

[0081] In the formula, v 3,i is the moving speed of the hydraulic cylinder in the i-th experiment, A 无杆腔 is the pressure-bearing area of the rodless chamber of the hydraulic cylinder, Q 变量泵 is the output flow rate of the variable pump.

[0082] S43. The flow rate Q through the oil return valve port of the arm joint multi-way valve is obtained from the oil return flow rate of the rod chamber of the arm cylinder and the oil return and regeneration flow rate 回油阀 :

[0083] Q 回油阀 = v 3,i × A 有杆腔 -(v 3,i × A 无杆腔 - Q 变量泵 ) = v3,i ×(A 有杆腔 -A 无杆腔 )+Q 变量泵

[0084] In the formula, Q 变量泵 is a known term, A 无杆腔 is the pressure-bearing area of the rodless cavity, A 有杆腔 is the pressure-bearing area of the rod cavity, P 无杆腔 is the pressure of the rodless cavity, P 有杆腔 is the pressure of the rod cavity, V 无杆腔 is the total volume of the rodless cavity and the connecting pipeline, V 有杆腔 is the total volume of the rod cavity and the connecting pipeline.

[0085] S5. Based on the flow-pressure continuity equation, the actual displacement of the multi-way valve spool is obtained through the actual flow rate of the oil return valve port: Based on the flow-pressure continuity equation, the actual displacement X of the multi-way valve spool is obtained through the actual flow rate of the oil return valve 实际 :

[0086]

[0087] In the formula, C d is the flow coefficient, A(X 实际 ) is the flow-through area of the oil return valve port of the multi-way valve when the spool displacement is X 实际 , ΔP is the pressure difference across the oil return valve port of the multi-way valve, ρ is the oil density, A -1 (X 实际 ) is the inverse function of A(X 实际 ).

[0088] Given the pressure difference and flow rate at the oil return valve port, the product of the flow-through area and the valve port flow coefficient is determined. Since the flow coefficient is a quantity that cannot be directly calculated and needs to be measured through a bench test. Therefore, using the known flow-through area, the actual displacement of the spool at this time is inversely deduced. Given the pressure difference and flow rate at the oil return valve port, the product of the flow-through area and the valve port flow coefficient is determined. Since the flow coefficient needs to be measured through a bench test. Therefore, using the known flow-through area, the actual displacement of the spool at this time is inversely deduced.

[0089] The valve calibration points are (I f,1 , X 实际，1 ), (I f,2 , X 实际，2 ), …, (I f,n , X 实际，n ); (I f,1 , X 指令，1 ), (I f,2 , X 指令，2 ), …, (I f,n , X 指令，n ).

[0090] By analyzing the valve calibration points at each spool displacement, the deviation between the spool displacement and the spool displacement curve of the multi-way valve is compensated to the input current of the second proportional relief valve, and the compensated spool displacement X of the multi-way valve is obtained. 阀开度 :

[0091]

[0092] In the formula, f f (I f ) is the variable pump output flow corresponding to the current value I f on the spool displacement curve of the multi-way valve.

[0093] The verification of the descending curve is based on the known hysteresis width of the input current and output spool displacement curves of the proportional relief valve and the multi-way valve in the bench test. By adding and subtracting the hysteresis width on the calibrated ascending curve, the corresponding descending curve is obtained.

[0094] Input the calibrated variable pump and multi-way valve into the control hydraulic system.

[0095] As Figure 2 shown, in the hydraulic system principle of the excavator pump valve calibration method, for the hydraulic circuits of the swing joint and the boom joint, the controller converts the handle signal operated by the driver into an electrical signal to control each component through the proportional relief valve. The relief valve acts as a safety valve to provide safety protection for the entire hydraulic system. The engine drives the variable pump to supply energy to the hydraulic system. The unloading valve, on the one hand, returns the minimum flow of the variable pump in the standby state of the excavator to the fuel tank, and on the other hand, acts as a speed regulating component for bypass throttling speed regulation. The swing joint multi-way valve acts as a direction control valve to control the swing direction, and the hydraulic swing motor acts as an actuator to perform the swing action. The boom joint multi-way valve acts as a direction control valve to control the boom excavation or unloading. The oil return regeneration valve guides the oil in the rod chamber of the boom excavation into the rodless chamber for reuse. The oil return regeneration cut-off valve cuts off the oil return regeneration function. The boom cylinder acts as an actuator to perform the boom excavation and unloading conditions.

[0096] As Figure 3As shown, the hydraulic system pump and valve calibration is achieved by performing specific continuous motions on the excavator. The variable pump is calibrated under impedance conditions: the excavator's swing motion is supplied solely by the rear pump, while the boom-lift motion is supplied simultaneously by the front and rear pumps. The rear pump is first calibrated using the excavator's swing motion as an example. Based on this, the front pump is indirectly calibrated using the boom-lift motion as an example. Calibration is performed using pump calibration points based on bench test curves. After the variable pump calibration is completed, the multi-way valve is calibrated under overrun conditions, where the load force and movement speed are moving downward at the same speed. The arm-linked multi-way valve is calibrated using the excavator's boom excavation motion, the arm-linked multi-way valve is calibrated using the boom-lowering motion, and the bucket-linked multi-way valve is calibrated using the bucket excavation motion. The arm-linked multi-way valve is calibrated using the same calibration method as the boom-linked and bucket-linked multi-way valves, and valve calibration points are also used.

[0097] like Figure 4 The figure shows the dual-pump oil supply logic of the excavator hydraulic system, and the specific sequential motions performed by the excavator during pump and valve calibration. Initially, the excavator arm is on the left side of the plane, with the boom at a 20° angle to the horizontal, and the arm and bucket cylinders fully retracted. The rear pump is calibrated using a single swing motion (the swing platform rotates 180° clockwise), with the arm positioned on the right side of the plane. Next, the front pump is calibrated using a single boom raise motion, with the boom at an 80° angle to the horizontal, and the arm and bucket cylinders fully retracted. This completes variable pump calibration. The bucket multi-way valve is calibrated using the excavator's bucket excavation motion, with the bucket cylinder shifting from fully retracted to fully extended. The arm excavation motion also calibrates the arm multi-way valve, with the arm cylinder shifting from fully retracted to fully extended. Finally, the arm lowering motion calibrates the arm multi-way valve, with the boom at a 40° angle to the horizontal.

[0098] The present invention is used for a dynamic compensation calibration method for an excavator pump-valve coordinated control hydraulic system. The method performs staged dynamic calibration and real-time data iterative correction on the hydraulic excavator pump and valve under different load conditions, dynamically compensates for the nonlinearity and uncertainty of the hydraulic system, and compensates for the matching errors of the variable pump, multi-way valve and proportional pressure reducing valve, thereby realizing accurate calibration of the hydraulic excavator pump and valve under complex operating conditions.

[0099] The above embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A dynamic compensation calibration method for the hydraulic system of collaborative control of the pump and valve of an excavator, characterized in that: It includes: Based on the bench test, obtain the curve of the input current of the first proportional relief valve and the output flow of the variable pump, and the curve of the input current of the second proportional relief valve and the spool displacement of the multi-way valve; Calibrate the variable pump under the impedance condition: Calibrate the post-variable pump through the swing motion of the excavator. Based on the output flow curve of the variable pump, calibrate the post-variable pump using n pump calibration points. Set the command speed and inherent displacement of the hydraulic swing motor to obtain the theoretical flow rate Q of the variable pump. 泵头理论 , input the input current of the corresponding first proportional relief valve according to the output flow curve of the variable pump to control the variable pump fuel supply system; Obtain the actual output flow rate Q of the variable pump based on the actual rotational speed of the slewing motor 泵头实际 , through the pump calibration points at various rotational speeds of the slewing motor, compensate the deviation between the output flow rate of the variable pump and the output flow rate curve of the variable pump to the input current of the first proportional relief valve, and obtain the compensated output flow rate of the rear variable pump; Based on the calibrated variable pump, calibrate the front variable pump through the single action of the boom lifting. The calibration of the front variable pump is the same as that of the rear variable pump; Based on the calibrated variable pump, calibrate the multi-way valve under the override condition: Set the spool displacement X1 of the multi-way valve of the stick connection. Obtain the input current of the second proportional relief valve according to the spool displacement curve of the multi-way valve, and then control the multi-way valve. Obtain the oil return regeneration flow according to the actual flow of the rodless chamber and the output flow of the variable pump. Obtain the flow through the oil return valve of the multi-way valve of the stick connection through the oil return flow of the rod chamber of the stick hydraulic cylinder and the oil return regeneration flow; Based on the flow-pressure continuity equation, obtain the actual spool displacement of the multi-way valve through the actual flow of the oil return valve. By analyzing the valve calibration points at each spool displacement, compensate the deviation between the spool displacement and the spool displacement curve of the multi-way valve to the input current of the second proportional relief valve to obtain the compensated spool displacement of the multi-way valve; Input the calibrated variable pump and multi-way valve into the control hydraulic system.

2. The dynamic compensation calibration method for the hydraulic system of the collaborative control of the excavator pump and valve according to claim 1, characterized in that: The theoretical flow rate Q of the variable pump 泵头理论 : Where, D m is the displacement of the slewing motor, V m is the total volume of the oil inlet chamber of the slewing motor and the connecting pipeline, P m,i is the pressure of the oil inlet chamber of the slewing motor. Under the condition that the hydraulic motor moves at a constant speed β is the bulk modulus of elasticity of the oil, N 1,i is the commanded speed of the hydraulic slewing motor, i is the number of repeated experiments, ΔQ 其他 is the flow loss of the unknown interference term.

3. The dynamic compensation calibration method for the hydraulic system of the excavator pump-valve collaborative control according to claim 1, characterized in that: Actual output flow rate Q of the variable pump 泵头实际 : where Q 容积效率损失 , Q 机械效率损失 are the flow rate losses of the hydraulic pump output caused by the volumetric efficiency and mechanical efficiency, N 2,i is the actual rotational speed of the hydraulic rotary motor, and the pump calibration points are (I b,1 , Q 泵头实际，1 ), (I b,2 , Q 泵头实际，2 ), …, (I b,n , Q 泵头实际，n ), (I b,1 , Q 泵头理论，1 ), (I b,2 , Q 泵头理论，2 ), …, (I b,n , Q 泵头理论，n ).

4. The dynamic compensation calibration method for the hydraulic system of the collaborative control of the excavator pump and valve according to claim 1, wherein: Output flow rate Q of the compensated post-variable pump 泵头流量 : where f b (I b ) is the current value I b and is the variable pump output flow corresponding to the variable pump output flow curve.

5. The dynamic compensation calibration method for the excavator pump-valve coordinated control hydraulic system according to claim 1, wherein: Return oil regeneration flow rate Q 泵头流量 : Q 回油再生 = v 3,i × A 无杆腔 - Q 变量泵 where, v 3,i is the moving speed of the hydraulic cylinder in the i-th experiment, A 无杆腔 is the pressure-bearing area of the rodless cavity of the hydraulic cylinder, Q 变量泵 is the output flow rate of the variable pump.

6. The dynamic compensation calibration method for the hydraulic system of the collaborative control of the excavator pump and valve according to claim 1, characterized in that: Flow rate Q of the oil return valve of the boom combined multi-way valve 回油阀 : Q 回油阀 = v 3,i × A 有杆腔 -(v 3,i × A 无杆腔 - Q 变量泵 ) = v 3,i × (A 有杆腔 - A 无杆腔 ) + Q 变量泵 where Q 变量泵 is a known term, A 无杆腔 is the pressure-bearing area of the rodless cavity, A 有杆腔 is the pressure-bearing area of the rod cavity, P 无杆腔 is the pressure of the rodless cavity, P 有杆腔 is the pressure of the rod cavity, V 无杆腔 is the total volume of the rodless cavity and the connecting pipe, V 有杆腔 is the total volume of the rod cavity and the connecting pipe.

7. The dynamic compensation calibration method for the hydraulic system of the collaborative control of the excavator pump valve according to claim 1, characterized in that: Actual displacement X of the multi-way valve spool 实际 : Where, C d is the flow coefficient, A(X 实际 ) is the flow area of the oil return valve port of the multi-way valve when the spool displacement is X 实际 , ΔP is the pressure difference across the oil return valve port of the multi-way valve, ρ is the oil density, A -1 (X 实际 ) is the inverse function of A(X 实际 ).

8. The dynamic compensation calibration method for the excavator pump-valve coordinated control hydraulic system according to claim 1, characterized in that: Compensated spool displacement X of the multi-way valve 阀开度 : Where, f f (I f ) is the output flow rate of the variable pump corresponding to the spool displacement curve of the multi-way valve at the current value I f .

9. The dynamic compensation calibration method for the hydraulic system of the excavator pump-valve collaborative control according to claim 1, wherein: Obtain the actual flow rates Q 无杆腔 and Q 有杆腔 of the two chambers based on the actual moving speed of the boom hydraulic cylinder: 无杆腔 、Q 有杆腔 : Wherein, under the condition that the hydraulic cylinder moves at a uniform speed

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