Motor hydraulic pump control method and system and engineering machinery

Abstract

The invention discloses a motor hydraulic pump control method and system and engineering machinery. The motor hydraulic pump control method comprises the steps that the real-time output pressure of a hydraulic pump under the current operation working condition is obtained; calling a control parameter group corresponding to a pressure interval to which the real-time output pressure belongs based on the real-time output pressure; wherein the control parameter group is obtained based on a parameter grading method and an off-line data analysis method and comprises theoretical output pressure of a plurality of hydraulic pumps, the highest motor hydraulic pump total efficiency corresponding to each flow division point of each theoretical output pressure, and the highest motor hydraulic pump total efficiency corresponding to each flow division point of each theoretical output pressure. The motor rotating speed and the hydraulic pump displacement correspond to the highest motor hydraulic pump total efficiency; the real-time required flow of the hydraulic pump is obtained, and the rotating speed of the motor and the displacement of the hydraulic pump are calculated in combination with the control parameter set; and controlling the motor and the hydraulic pump based on the rotating speed of the motor and the displacement of the hydraulic pump. The method of parameter grading and offline data analysis is adopted, the calculation amount is small, the system response is fast, and the occupied memory is small.

Description

Technical Field

[0001] The present invention belongs to the technical field of engineering machinery, and in particular relates to a motor hydraulic pump control method, system and engineering machinery. Background Art

[0002] Traditional engineering machinery produces a lot of exhaust gas, which pollutes the environment. To solve this problem, it is proposed to use a motor-driven hydraulic pump to provide hydraulic power to the actuator to replace the traditional diesel engine-driven hydraulic pump. At present, the hydraulic pump of the hydraulic system of engineering machinery usually adopts a combination of a fixed speed motor and a variable pump, or a combination of a variable speed motor and a fixed displacement pump. This often makes the motor or hydraulic pump unable to work in the high efficiency range, and the high energy consumption of the hydraulic pump reduces the endurance of the engineering machinery.

[0003] In the Chinese invention patent application with publication number CN115111210A, a motor pump hydraulic efficiency optimization control method is disclosed. The volumetric efficiency and hydraulic mechanical efficiency of the hydraulic pump are determined by looking up the hydraulic pump efficiency table Map1. Table Map1 contains the pump volumetric efficiency and hydraulic mechanical efficiency corresponding to the pump displacement and output pressure at the corresponding speed. The motor efficiency is determined by looking up the motor efficiency table Map2. Table Map2 contains the motor efficiency corresponding to the motor torque and speed. The total efficiency of the motor pump can be determined by the function of the motor efficiency and the efficiency of each variable pump. The control unit determines the time required for the variable pump displacement to change by looking up the table. The motor shaft response time is determined by an empirical formula or by looking up the table. The total response time of the motor pump is the larger value of the motor response time and the hydraulic pump response time. After determining the total efficiency of the motor pump and the motor pump response time, the control unit optimizes the hydraulic pump efficiency with these two parameters as optimization targets and the motor speed and hydraulic pump displacement as optimization parameters. This method requires real-time calculation of the hydraulic pump efficiency and motor efficiency, and simultaneously takes the motor response time and the hydraulic pump response time as online optimization targets. The two optimization targets of the motor pump total efficiency and the motor pump response time are assigned respective weight values, and the optimal total efficiency and optimal response time of the motor pump are determined through a complex optimization algorithm. The system and algorithm are relatively complex, which is not conducive to system stability and has high performance requirements on the controller.

[0004] In the Chinese invention patent application with publication number CN117450049A, a hydraulic pump efficiency optimization control method is disclosed. First, a motor map established by the relationship between motor efficiency, motor torque and motor speed is obtained, and the motor efficiency corresponding to each candidate parameter group under the real-time output pressure is determined according to the motor map. The motor speed is determined according to the motor frequency and the number of motor pole pairs. The mechanical efficiency of the hydraulic pump corresponding to each candidate parameter group under the real-time output pressure is determined according to the total torque and torque loss value on the transmission shaft; the volumetric efficiency of the hydraulic pump corresponding to each candidate parameter group under the real-time output pressure is determined, and the hydraulic pump efficiency corresponding to each candidate parameter group is determined according to the mechanical efficiency and volumetric efficiency of the hydraulic pump; the total system efficiency is the product of the motor efficiency, the volumetric efficiency of the hydraulic pump and the mechanical efficiency of the hydraulic pump. The real-time output pressure of the hydraulic pump under the current operating condition is obtained; the total system efficiency corresponding to each candidate parameter group under the real-time output pressure is determined; the candidate parameter group with the largest total system efficiency is used as the control parameter group of the hydraulic system; the operation of the motor pump group of the hydraulic system is controlled according to the control parameter group. This method requires online calculation of the hydraulic pump mechanical efficiency, hydraulic pump volumetric efficiency and motor efficiency respectively; the total torque and torque loss values ​​on the transmission shaft determine the mechanical efficiency of the hydraulic pump corresponding to each candidate parameter group under the real-time output pressure. The hydraulic pump mechanical efficiency also needs to consider the torque loss coefficient generated by pressure and the torque loss coefficient generated by viscous force; the leakage flow of the hydraulic pump is determined based on the real-time output pressure and the hydraulic pump leakage coefficient. The motor speed is determined based on the motor frequency and the number of motor pole pairs. This method requires more parameters and coefficients to be determined, and the amount of data processed online is large, which affects the response time of the system.

[0005] It can be seen that both of the above two technical methods need to check the motor efficiency and hydraulic pump efficiency tables respectively and simultaneously, which requires a large amount of calculation, many parameters need to be determined online, the system and algorithm are complex, the response is slow, and the controller has high computing performance requirements. Summary of the invention

[0006] In view of the above problems, the present invention proposes a motor hydraulic pump control method, system and engineering machinery, which adopts parameter classification and off-line data analysis methods, with low calculation amount, fast system response and small memory usage.

[0007] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0008] In a first aspect, the present invention provides a motor hydraulic pump control method, comprising:

[0009] Obtain the real-time output pressure of the hydraulic pump under the current operating conditions;

[0010] Based on the real-time output pressure, a control parameter group corresponding to the pressure interval to which the real-time output pressure belongs is called; wherein the control parameter group is obtained based on a parameter classification method and an offline data analysis method, and includes a plurality of theoretical output pressures of hydraulic pumps, a maximum motor hydraulic pump total efficiency corresponding to each hydraulic pump flow rate under each theoretical output pressure, and a motor speed and a hydraulic pump displacement corresponding to the maximum motor hydraulic pump total efficiency;

[0011] Obtaining the real-time required flow of the hydraulic pump, and calculating the motor speed and the hydraulic pump displacement in combination with the control parameter group;

[0012] The motor and the hydraulic pump are controlled based on the motor speed and the hydraulic pump displacement.

[0013] In combination with the first aspect, optionally, the method for constructing the control parameter group includes:

[0014] Divide the theoretical output pressure range of the hydraulic pump into several intervals to obtain several theoretical output pressures of the hydraulic pump;

[0015] Divide the flow range of the hydraulic pump into several intervals to obtain several hydraulic pump flow rates;

[0016] A control parameter group is established based on the highest motor hydraulic pump total efficiency obtained under different theoretical output pressures and different hydraulic pump flow rates, and the motor speed and hydraulic pump displacement corresponding to the highest motor hydraulic pump total efficiency.

[0017] In combination with the first aspect, optionally, the method for establishing the control parameter group includes:

[0018] Keep the motor speed at n0 and set the theoretical output pressure of the hydraulic pump to P0, P1, ..., P N1-1 , P N1 , N1 is the total theoretical output pressure of the hydraulic pump, and controls the displacement of the hydraulic pump between 0 and q max —0 continuous periodic ramp change, q max is the maximum hydraulic pump displacement, and after running for a period of time, the corresponding hydraulic pump flow, the actual output pressure of the hydraulic pump, the hydraulic pump displacement, the motor speed, the input DC voltage of the motor controller, and the input DC current of the motor controller are obtained, and the motor controller is connected to the motor;

[0019] Keep the motor speed at n1 and set the theoretical output pressure of the hydraulic pump to Control the hydraulic pump displacement between 0 and q max —0 continuous periodic ramp changes, and after running for a period of time, the corresponding hydraulic pump flow, actual output pressure of the hydraulic pump, hydraulic pump displacement, motor speed, input DC voltage of the motor controller, and input DC current of the motor controller are obtained;

[0020] ……;

[0021] Keep the motor speed at , N2 is the total number of motor speeds, and the theoretical output pressure of the hydraulic pump is set to P0, Control the hydraulic pump displacement between 0 and q max —0 continuous periodic ramp changes, and after running for a period of time, the corresponding hydraulic pump flow, actual output pressure of the hydraulic pump, hydraulic pump displacement, motor speed, input DC voltage of the motor controller, and input DC current of the motor controller are obtained;

[0022] Based on the acquired hydraulic pump flow, the actual output pressure of the hydraulic pump, the input DC voltage of the motor controller, and the input DC current of the motor controller, the total efficiency of all motor hydraulic pumps under different theoretical output pressures and different hydraulic pump flows is calculated;

[0023] Screen out the highest motor hydraulic pump total efficiency under different theoretical output pressures and different hydraulic pump flow rates, as well as the motor speed and hydraulic pump displacement corresponding to the highest motor hydraulic pump total efficiency;

[0024] Based on the highest motor hydraulic pump total efficiency obtained under different theoretical output pressures and different hydraulic pump flow rates, and the motor speed and hydraulic pump displacement corresponding to the highest motor hydraulic pump total efficiency, a corresponding control parameter group is established.

[0025] In combination with the first aspect, optionally, the calculation formula of the total efficiency of the motor hydraulic pump is:

[0026] η=(PQ / 60) / (UI / 1000);

[0027] Among them, η is the total efficiency of the motor hydraulic pump, P is the actual output pressure of the hydraulic pump, unit is MPa; Q is the flow rate of the hydraulic pump, unit is L / min; U is the input DC voltage of the motor controller, unit is V; I is the input DC current of the motor controller, unit is A.

[0028] In combination with the first aspect, optionally, calling, based on the real-time output pressure, a control parameter group corresponding to a pressure interval to which the real-time output pressure belongs includes:

[0029] Find out the pressure interval rate to which the real-time output pressure belongs;

[0030] Comparing the real-time output pressure with an average pressure calculated based on pressure values ​​at both ends of the pressure interval;

[0031] If the real-time output pressure is greater than the average pressure, the control parameter group corresponding to the larger pressure at both ends is used as the control parameter group corresponding to the real-time output pressure;

[0032] If the real-time output pressure is less than or equal to the average pressure, the control parameter group corresponding to the smaller pressure between the two end pressures is used as the control parameter group corresponding to the real-time output pressure.

[0033] In combination with the first aspect, optionally, obtaining the real-time required flow of the hydraulic pump and calculating the motor speed and the hydraulic pump displacement in combination with the control parameter group include:

[0034] Get the real-time required flow of the hydraulic pump;

[0035] Based on the real-time required flow and the control parameter group, the hydraulic pump displacement q is calculated by table lookup and interpolation;

[0036] According to the formula Calculate the motor speed n, where Q is the real-time required flow of the hydraulic pump.

[0037] In combination with the first aspect, optionally, obtaining the real-time required flow of the hydraulic pump and calculating the motor speed and the hydraulic pump displacement in combination with the control parameter group include:

[0038] Get the real-time required flow of the hydraulic pump;

[0039] Based on the real-time required flow and the control parameter group, the motor speed n is calculated by table lookup and interpolation;

[0040] According to the formula Calculate the hydraulic pump displacement q, where Q is the real-time required flow of the hydraulic pump.

[0041] In a second aspect, the present invention provides a motor hydraulic pump control system, comprising:

[0042] A real-time output pressure acquisition module is used to obtain the real-time output pressure of the hydraulic pump under the current operating conditions;

[0043] A control parameter group calling module is used to call the control parameter group corresponding to the pressure interval to which the real-time output pressure belongs based on the real-time output pressure; wherein the control parameter group is obtained based on a parameter classification method and an offline data analysis method, and includes the theoretical output pressures of several hydraulic pumps, the highest motor hydraulic pump total efficiency corresponding to each hydraulic pump flow rate under each theoretical output pressure, and the motor speed and hydraulic pump displacement corresponding to the highest motor hydraulic pump total efficiency;

[0044] A calculation module, used to obtain the real-time required flow of the hydraulic pump, and calculate the motor speed and the hydraulic pump displacement in combination with the control parameter group;

[0045] A control module is used to control the motor and the hydraulic pump based on the motor speed and the hydraulic pump displacement.

[0046] In a third aspect, the present invention provides a motor hydraulic pump control system, including a pressure sensor, a flow command input device and a controller;

[0047] The pressure sensor is used to detect the real-time output pressure of the hydraulic pump under the current operating condition and send it to the controller;

[0048] The flow command input device is used to input the real-time required flow under the current operating conditions and send it to the controller;

[0049] The controller is configured to execute the method according to any one of the first aspects.

[0050] In a fourth aspect, the present invention provides an engineering machine, comprising the motor hydraulic pump control system described in any one of the second aspect or the third aspect.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] The present invention adopts the method of parameter grading and offline data analysis, which has the advantages of small amount of calculation, fast system response and small memory usage. Specifically, the present invention grades the motor speed, hydraulic pump flow, hydraulic pump displacement and the theoretical output pressure of the hydraulic pump, and establishes a control parameter group of the hydraulic pump flow demand and the highest motor hydraulic pump total efficiency, motor speed and hydraulic pump displacement in each pressure grading interval. The control parameter group is stored in the controller, and the controller obtains the real-time output pressure of the hydraulic pump under the current operating conditions, and calls the control parameter group of the corresponding pressure interval as the control parameter group of the hydraulic pump. In this way, the control parameter group corresponding to the highest point of the total efficiency of the motor hydraulic pump can be obtained, the input is the real-time required flow of the hydraulic pump, and the output is the motor speed and hydraulic pump displacement, which can be used to improve the working efficiency of the hydraulic pump system. Using the method of parameter grading and offline data analysis, the calculation amount is small, the system response is fast, and small memory usage is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor, among which:

[0054] Figure 1 A schematic flow chart of a motor hydraulic pump control method according to an embodiment of the present invention;

[0055] Figure 2 A structural block diagram of a motor hydraulic pump control system according to an embodiment of the present invention;

[0056] Figure 3A structural block diagram of a single-motor hydraulic pump system according to an embodiment of the present invention;

[0057] Figure 4 A structural block diagram of a multi-motor hydraulic pump system according to an embodiment of the present invention;

[0058] in:

[0059] 101 - motor, 102 - motor controller, 103 - hydraulic pump, 104 - pressure sensor, 105 - controller, 106 - command input device. DETAILED DESCRIPTION

[0060] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0062] Example 1

[0063] The present invention provides a motor hydraulic pump control method. Figure 1 As shown, the following steps are included:

[0064] (1) Obtaining the real-time output pressure of the hydraulic pump under the current operating conditions;

[0065] (2) based on the real-time output pressure, calling a control parameter group corresponding to the pressure interval to which the real-time output pressure belongs; wherein the control parameter group is obtained based on a parameter classification method and an offline data analysis method, and includes a plurality of theoretical output pressures of hydraulic pumps, a maximum motor hydraulic pump total efficiency corresponding to each hydraulic pump flow rate at each theoretical output pressure, and a motor speed and a hydraulic pump displacement corresponding to the maximum motor hydraulic pump total efficiency;

[0066] (3) obtaining the real-time required flow of the hydraulic pump, and calculating the motor speed and the hydraulic pump displacement in combination with the control parameter group;

[0067] (4) Controlling the motor and the hydraulic pump based on the motor speed and the hydraulic pump displacement.

[0068] In a specific implementation of the embodiment of the present invention, the method for constructing the control parameter group includes:

[0069] Divide the theoretical output pressure range of the hydraulic pump into several intervals to obtain several theoretical output pressures of the hydraulic pump;

[0070] Divide the flow range of the hydraulic pump into several intervals to obtain several hydraulic pump flow rates;

[0071] A control parameter group is established based on the highest motor hydraulic pump total efficiency obtained under different theoretical output pressures and different hydraulic pump flow rates, and the motor speed and hydraulic pump displacement corresponding to the highest motor hydraulic pump total efficiency.

[0072] In a specific implementation of the embodiment of the present invention, the method for establishing the control parameter group includes:

[0073] Keep the motor speed at n0 and set the theoretical output pressure of the hydraulic pump to N1 is the total theoretical output pressure of the hydraulic pump, which controls the displacement of the hydraulic pump between 0 and q max —0 continuous periodic ramp change, q max is the maximum hydraulic pump displacement, and after running for a period of time, the corresponding hydraulic pump flow, the actual output pressure of the hydraulic pump, the hydraulic pump displacement, the motor speed, the input DC voltage of the motor controller, and the input DC current of the motor controller are obtained, and the motor controller is connected to the motor;

[0074] Keep the motor speed at n1 and set the theoretical output pressure of the hydraulic pump to Control the hydraulic pump displacement between 0 and q max —0 continuous periodic ramp changes, and after running for a period of time, the corresponding hydraulic pump flow, actual output pressure of the hydraulic pump, hydraulic pump displacement, motor speed, input DC voltage of the motor controller, and input DC current of the motor controller are obtained;

[0075] ……;

[0076] Keep the motor speed at N3 is the total number of motor speeds, and the theoretical output pressures of the hydraulic pump are set to P0, Control the hydraulic pump displacement between 0 and q max—0 continuous periodic ramp changes, and after running for a period of time, the corresponding hydraulic pump flow, actual output pressure of the hydraulic pump, hydraulic pump displacement, motor speed, input DC voltage of the motor controller, and input DC current of the motor controller are obtained;

[0077] Based on the acquired hydraulic pump flow, the actual output pressure of the hydraulic pump, the input DC voltage of the motor controller, and the input DC current of the motor controller, the total efficiency of all motor hydraulic pumps under different theoretical output pressures and different hydraulic pump flows is calculated;

[0078] Screen out the highest motor hydraulic pump total efficiency under different theoretical output pressures and different hydraulic pump flow rates, as well as the motor speed and hydraulic pump displacement corresponding to the highest motor hydraulic pump total efficiency;

[0079] Based on the highest motor hydraulic pump total efficiency obtained under different theoretical output pressures and different hydraulic pump flow rates, and the motor speed and hydraulic pump displacement corresponding to the highest motor hydraulic pump total efficiency, a corresponding control parameter group is established.

[0080] In a specific implementation of the embodiment of the present invention, the calculation formula of the total efficiency of the motor hydraulic pump is:

[0081] η=(PQ / 60) / (UI / 1000);

[0082] Among them, η is the total efficiency of the motor hydraulic pump, P is the actual output pressure of the hydraulic pump, unit is MPa; Q is the flow rate of the hydraulic pump, unit is L / min; U is the input DC voltage of the motor controller, unit is V; I is the input DC current of the motor controller, unit is A.

[0083] In a specific implementation of the embodiment of the present invention, calling the control parameter group corresponding to the pressure interval to which the real-time output pressure belongs based on the real-time output pressure includes:

[0084] Find out the pressure interval rate to which the real-time output pressure belongs;

[0085] Comparing the real-time output pressure with an average pressure calculated based on pressure values ​​at both ends of the pressure interval;

[0086] If the real-time output pressure is greater than the average pressure, the control parameter group corresponding to the larger pressure at both ends is used as the control parameter group corresponding to the real-time output pressure;

[0087] If the real-time output pressure is less than or equal to the average pressure, the control parameter group corresponding to the smaller pressure between the two end pressures is used as the control parameter group corresponding to the real-time output pressure.

[0088] In a specific implementation of the embodiment of the present invention, the step of obtaining the real-time required flow of the hydraulic pump and calculating the motor speed and the hydraulic pump displacement in combination with the control parameter group includes:

[0089] Get the real-time required flow of the hydraulic pump;

[0090] Based on the real-time required flow and the control parameter group, the hydraulic pump displacement q is calculated by table lookup and interpolation;

[0091] According to the formula Calculate the motor speed n, where Q is the real-time required flow of the hydraulic pump.

[0092] In a specific implementation of the embodiment of the present invention, the step of obtaining the real-time required flow of the hydraulic pump and calculating the motor speed and the hydraulic pump displacement in combination with the control parameter group includes:

[0093] Get the real-time required flow of the hydraulic pump;

[0094] Based on the real-time required flow and the control parameter group, the motor speed n is calculated by table lookup and interpolation;

[0095] According to the formula Calculate the hydraulic pump displacement q, where Q is the real-time required flow of the hydraulic pump.

[0096] The motor hydraulic pump control method in the embodiment of the present invention is described in detail below in conjunction with a specific implementation.

[0097] The theoretical output pressure range of the hydraulic pump 103 is divided into several intervals to obtain several theoretical output pressures of the hydraulic pump 103; the hydraulic pump flow rate is divided into several intervals to obtain several hydraulic pump flow rates; based on the highest motor hydraulic pump total efficiency obtained under different theoretical output pressures and different hydraulic pump flow rates, and the motor speed and hydraulic pump displacement corresponding to the highest motor hydraulic pump total efficiency, a corresponding control parameter group is established to finally form a control parameter data table;

[0098] The established control parameter data table is stored in the controller 105 (such as a vehicle controller);

[0099] The controller 105 obtains the real-time output pressure of the hydraulic pump 103 under the current operating condition through the pressure sensor 104 connected to the hydraulic pump 103, automatically calls the hydraulic pump flow rate and the highest motor hydraulic pump total efficiency, motor speed and hydraulic pump displacement of the corresponding pressure range from the control parameter data table, and outputs the motor speed and hydraulic pump displacement instructions to adjust the speed of the motor 101 and the hydraulic pump displacement of the hydraulic pump 103, so as to achieve automatic optimization of the motor 101 speed and the hydraulic pump 103 displacement when the real-time demand flow of the hydraulic pump 103 and the output pressure at the outlet of the hydraulic pump 103 are constantly changing, so as to ensure that the motor 101 and the hydraulic pump 103 always work in the high-efficiency range, and improve the working efficiency of the motor 101 and the hydraulic pump 103. In the specific implementation process, the controller 105 is connected to the pressure sensor 104 and the hydraulic pump displacement control solenoid valve. The motor 101 is also connected to the motor controller 102.

[0100] In the present invention, the motor speed, hydraulic pump flow, hydraulic pump displacement and theoretical output pressure of the hydraulic pump are graded to realize data collection and processing, which greatly reduces the amount of data collection and processing, has low requirements on the processing power and storage space of the controller 105, and improves the response time of the system.

[0101] In the present invention, based on the highest motor hydraulic pump total efficiency obtained under different theoretical output pressures and different hydraulic pump flow rates, and the motor speed and hydraulic pump displacement corresponding to the highest motor hydraulic pump total efficiency, a corresponding control parameter group is established, specifically including the following steps:

[0102] The theoretical output pressure range of the hydraulic pump 103 is equally divided into N1 different theoretical output pressure values, namely P0, P1, ..., P N1-1 , P N1 ; According to the flow range of the hydraulic pump, the hydraulic pump flow is equally divided into N3 different hydraulic pump flow values, namely Q0, Q1, ... Q N3-1 , Q N3 ; According to the motor speed range, the motor speed is divided into N2 different motor speed values, namely n0, n1, ..., n N2-1 ,n N2 In the specific implementation process, N1=N2=N3=N can be set;

[0103] The hydraulic pump 103 is operated on the test bench according to different working condition combinations (i.e., different theoretical output pressures, different hydraulic pump flows, different hydraulic pump displacements, and different motor speeds), and the hydraulic pump flow, actual output pressure of the hydraulic pump, hydraulic pump displacement, motor speed, input DC voltage of the motor controller, and input DC current of the motor controller within a certain period of time are collected.

[0104] Based on the acquired hydraulic pump flow, the actual output pressure of the hydraulic pump, the input DC voltage of the motor controller, and the input DC current of the motor controller, the total efficiency of all motor hydraulic pumps under different theoretical output pressures and different hydraulic pump flows is calculated. The calculation formula of the total efficiency of the motor hydraulic pump is:

[0105] η=(PQ / 60) / (UI / 1000);

[0106] Among them, η is the total efficiency of the motor hydraulic pump, P is the actual output pressure of the hydraulic pump, unit is MPa; Q is the flow rate of the hydraulic pump, unit is L / min; U is the input DC voltage of the motor controller, unit is V; I is the input DC current of the motor controller, unit is A.

[0107] When the theoretical output pressure at the outlet of the hydraulic pump is P0, different hydraulic pump flow rates (Q0, Q1, ... Q N-1 , Q N ) The total efficiency of all motor hydraulic pumps under ) is shown in Table 1.

[0108] Table 1

[0109]

[0110] Screen out the highest motor hydraulic pump total efficiency under different theoretical output pressures and different hydraulic pump flow rates, as well as the motor speed and hydraulic pump displacement corresponding to the highest motor hydraulic pump total efficiency;

[0111] Based on the highest motor hydraulic pump total efficiency obtained under different theoretical output pressures and different hydraulic pump flow rates, as well as the motor speed and hydraulic pump displacement corresponding to the highest motor hydraulic pump total efficiency, a corresponding control parameter group is established, see Table 2 for details.

[0112] Table 2

[0113]

[0114] Among them, the highest motor hydraulic pump total efficiency and the motor speed and hydraulic pump displacement corresponding to the highest motor hydraulic pump total efficiency are screened out, including:

[0115] In the control parameter group corresponding to the theoretical output pressure P0, by comparing the total efficiency of the motor hydraulic pump under different motor speeds and hydraulic pump displacements at the same flow rate Q0, the control parameter group with the highest total efficiency of the motor hydraulic pump is selected as the control parameter group of the hydraulic pump. Repeat the previous steps to determine the hydraulic pump flow rates Q0, Q1, ... Q N-1 , Q N The maximum total efficiency of the motor hydraulic pump at the theoretical output pressure P0, and the motor speed and hydraulic pump displacement corresponding to the maximum total efficiency of the motor hydraulic pump.

[0116] Using the above method, the theoretical output pressures P0, P1, ... P N-1 , P N Establish the flow rates Q0, Q1, ... Q N-1 , Q N The corresponding maximum motor hydraulic pump total efficiency, and the motor speed and hydraulic pump displacement corresponding to the maximum motor hydraulic pump total efficiency.

[0117] In actual application, the controller obtains the real-time output pressure of the hydraulic pump under the current operating condition through the pressure sensor 104, and the controller 105 obtains the real-time required flow of the hydraulic pump 103 through the command input device 106; based on the real-time required flow and the control parameter group, the hydraulic pump displacement q is calculated by table lookup and interpolation; according to the formula The motor speed n is calculated, where Q is the real-time required flow rate of the hydraulic pump. Alternatively, the controller 105 obtains the real-time required flow rate of the hydraulic pump 103 through the command input device 106; based on the real-time required flow rate and the control parameter group, the motor speed n is calculated by table lookup and interpolation; according to the formula Calculate the hydraulic pump displacement q, where Q is the real-time required flow of the hydraulic pump.

[0118] The motor hydraulic pump control method in the embodiment of the present invention is described in detail below in conjunction with a specific implementation.

[0119] The motor speed n is 500rpm, the hydraulic pump flow Q is 5L / min, and the maximum value of the motor speed n is n max , n max =5000rpm, the maximum displacement of the hydraulic pump is q max ,q max =50ml / r:

[0120] (1): n1 = 500, Q 1x =(5,10,15,20,25), q 1x =Q 1x / n1;

[0121] (2): n2 = 1000, Q 2x =(5,10......45,50), q 2x =Q 2x / n2; ......;

[0123] (N-1): n N-1 =4500, Q (N-1)x =(5,10,……,220,225), q N-1 =Q(N-1)x / n N-1 ;

[0124] (N): n N =5000, Q Nx =(5,10,……,245,250), q Nx =Q Nx / n N ;

[0125] Combine the relevant test data and efficiency formula corresponding to the theoretical output pressure P = 5Mpa of the hydraulic pump to calculate Q 1x , Q 2x ,......Q (N-1)x , Q Nx The corresponding total efficiency of the motor hydraulic pump is as follows: η = (PQ / 60) / (UI / 1000).

[0126] Assume the following results:

[0127] (1)Q=180, (q1,n1)=(45,4000), η1=0.81;

[0128] (2) Q=180, (q2,n2)=(40,4500), η2=0.83;

[0129] (3) Q=180, (q3,n3)=(36,5000), η3=0.82;

[0130] Then the control parameter group (q2, n2) = (40, 4500) of the total efficiency η2 of the motor hydraulic pump is taken as the control parameter group for Q = 180 in the P = 5Mpa range.

[0131] Repeat the above steps to determine the theoretical output pressure of the hydraulic pump P = 5, 10... (P max -5), P max (Unit: MPa) corresponds to the highest motor hydraulic pump total efficiency η and control parameter group (q,n) of Q=5,10......245,250 (Unit: L / min). Write the control parameter group (Q,q,η) or (Q,n,η) or (Q,q,n,η) corresponding to each highest total efficiency into the controller for storage.

[0132] In actual application, input signals are collected: for example, the real-time required flow rate of the hydraulic pump Q=88L / min, and the real-time output pressure of the hydraulic pump P=18MPa.

[0133] Pressure range judgment:

[0134] For example, P=18MPa belongs to the (15, 20]MPa range.

[0135] Call the control parameter group corresponding to the pressure range:

[0136] The control parameter group corresponding to P=20MPa needs to be called.

[0137] Query the control parameter group to determine the displacement:

[0138] In the control parameter group, Q1=85, assuming that the displacement corresponding to Q1 is 90%q max ;

[0139] In the control parameter group, Q2=90, assuming that the displacement corresponding to Q2 is 80%q max ;

[0140] By interpolation, we can calculate that the displacement corresponding to Q=88 is 84%q max .

[0141] Calculate the speed from the flow and displacement:

[0142] Speed ​​= flow rate / displacement.

[0143] The displacement is converted into a current signal and output to the hydraulic pump variable, and a speed signal is output to the motor controller 102 to adjust the motor speed.

[0144] Example 2

[0145] In an embodiment of the present invention, a motor hydraulic pump control system is provided. Figure 2 As shown, including:

[0146] A real-time output pressure acquisition module is used to obtain the real-time output pressure of the hydraulic pump under the current operating conditions;

[0147] A control parameter group calling module is used to call the control parameter group corresponding to the pressure interval to which the real-time output pressure belongs based on the real-time output pressure; wherein the control parameter group is obtained based on a parameter classification method and an offline data analysis method, and includes the theoretical output pressures of several hydraulic pumps, the highest motor hydraulic pump total efficiency corresponding to each hydraulic pump flow rate under each theoretical output pressure, and the motor speed and hydraulic pump displacement corresponding to the highest motor hydraulic pump total efficiency;

[0148] A calculation module, used to obtain the real-time required flow of the hydraulic pump, and calculate the motor speed and the hydraulic pump displacement in combination with the control parameter group;

[0149] A control module is used to control the motor and the hydraulic pump based on the motor speed and the hydraulic pump displacement.

[0150] The rest are the same as in Example 1.

[0151] Example 3

[0152] The embodiment of the present invention provides a motor hydraulic pump control system, including a pressure sensor 104, a flow command input device 106 and a controller 105;

[0153] The pressure sensor 104 is used to detect the real-time output pressure of the hydraulic pump under the current operating condition and send it to the controller 105;

[0154] The flow command input device 106 is used to input the real-time required flow under the current operating conditions and send it to the controller 105;

[0155] The controller 105 is configured to execute the method described in any one of the first embodiments.

[0156] Example 4

[0157] An embodiment of the present invention provides an engineering machinery, comprising the motor hydraulic pump control system described in any one of Embodiment 2 or Embodiment 3.

[0158] like Figure 3 and Figure 4 As shown, the motor hydraulic pump control system is connected to the motor 101 and the hydraulic pump 103 , and the motor hydraulic pump control system outputs the motor speed and the hydraulic pump displacement to control the motor 101 and the hydraulic pump 103 .

[0159] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0160] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0161] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0162] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0163] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.

[0164] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A motor hydraulic pump control method, characterized in that: include: Obtain the real-time output pressure of the hydraulic pump under the current operating conditions; Based on the real-time output pressure, a control parameter group corresponding to the pressure interval to which the real-time output pressure belongs is called; wherein the control parameter group is obtained based on a parameter classification method and an offline data analysis method, and includes a plurality of theoretical output pressures of hydraulic pumps, a maximum motor hydraulic pump total efficiency corresponding to each hydraulic pump flow rate under each theoretical output pressure, and a motor speed and a hydraulic pump displacement corresponding to the maximum motor hydraulic pump total efficiency; Obtaining the real-time required flow of the hydraulic pump, and calculating the motor speed and the hydraulic pump displacement in combination with the control parameter group; The motor and the hydraulic pump are controlled based on the motor speed and the hydraulic pump displacement.

2. A motor hydraulic pump control method according to claim 1, characterized in that: The method for constructing the control parameter group includes: Divide the theoretical output pressure range of the hydraulic pump into several intervals to obtain the theoretical output pressures of several hydraulic pumps; Divide the flow range of the hydraulic pump into several intervals to obtain several hydraulic pump flow rates; A control parameter group is established based on the highest motor hydraulic pump total efficiency obtained under different theoretical output pressures and different hydraulic pump flow rates, and the motor speed and hydraulic pump displacement corresponding to the highest motor hydraulic pump total efficiency.

3. A motor hydraulic pump control method according to claim 2, characterized in that: The method for establishing the control parameter group includes: Keep the motor speed at n0 and set the theoretical output pressure of the hydraulic pump to N1 is the total theoretical output pressure of the hydraulic pump, which controls the displacement of the hydraulic pump between 0 and q max —0 continuous periodic ramp change, q max is the maximum hydraulic pump displacement, and after running for a period of time, the corresponding hydraulic pump flow, the actual output pressure of the hydraulic pump, the hydraulic pump displacement, the motor speed, the input DC voltage of the motor controller, and the input DC current of the motor controller are obtained, and the motor controller is connected to the motor; Keep the motor speed at n1 and set the theoretical output pressure of the hydraulic pump to Control the hydraulic pump displacement between 0 and q max —0 continuous periodic ramp changes, and after running for a period of time, the corresponding hydraulic pump flow, actual output pressure of the hydraulic pump, hydraulic pump displacement, motor speed, input DC voltage of the motor controller, and input DC current of the motor controller are obtained; ……； Keep the motor speed at N2 is the total number of motor speeds, and the theoretical output pressures of the hydraulic pump are set to P0, Control the hydraulic pump displacement between 0 and q max —0 continuous periodic ramp changes, and after running for a period of time, the corresponding hydraulic pump flow, actual output pressure of the hydraulic pump, hydraulic pump displacement, motor speed, input DC voltage of the motor controller, and input DC current of the motor controller are obtained; Based on the acquired hydraulic pump flow, the actual output pressure of the hydraulic pump, the input DC voltage of the motor controller, and the input DC current of the motor controller, the total efficiency of all motor hydraulic pumps under different theoretical output pressures and different hydraulic pump flows is calculated; Screen out the highest motor hydraulic pump total efficiency under different theoretical output pressures and different hydraulic pump flow rates, as well as the motor speed and hydraulic pump displacement corresponding to the highest motor hydraulic pump total efficiency; Based on the highest motor hydraulic pump total efficiency obtained under different theoretical output pressures and different hydraulic pump flow rates, and the motor speed and hydraulic pump displacement corresponding to the highest motor hydraulic pump total efficiency, a corresponding control parameter group is established.

4. A motor hydraulic pump control method according to claim 3, characterized in that: The calculation formula of the total efficiency of the motor hydraulic pump is: η=(PQ / 60) / (UI / 1000); Among them, η is the total efficiency of the motor hydraulic pump, P is the actual output pressure of the hydraulic pump, unit is MPa; Q is the flow rate of the hydraulic pump, unit is L / min; U is the input DC voltage of the motor controller, unit is V; I is the input DC current of the motor controller, unit is A.

5. The motor hydraulic pump control method according to claim 2, characterized in that: The calling of the control parameter group corresponding to the pressure interval to which the real-time output pressure belongs based on the real-time output pressure includes: Find out the pressure interval rate to which the real-time output pressure belongs; Comparing the real-time output pressure with an average pressure calculated based on pressure values ​​at both ends of the pressure interval; If the real-time output pressure is greater than the average pressure, the control parameter group corresponding to the larger pressure at both ends is used as the control parameter group corresponding to the real-time output pressure; If the real-time output pressure is less than or equal to the average pressure, the control parameter group corresponding to the smaller pressure between the two end pressures is used as the control parameter group corresponding to the real-time output pressure.

6. A motor hydraulic pump control method according to claim 2, characterized in that: The method of obtaining the real-time required flow of the hydraulic pump and calculating the motor speed and the hydraulic pump displacement in combination with the control parameter group includes: Get the real-time required flow of the hydraulic pump; Based on the real-time required flow and the control parameter group, the hydraulic pump displacement q is calculated by table lookup and interpolation; According to the formula Calculate the motor speed n, where Q is the real-time required flow of the hydraulic pump.

7. A motor hydraulic pump control method according to claim 2, characterized in that: The method of obtaining the real-time required flow of the hydraulic pump and calculating the motor speed and the hydraulic pump displacement in combination with the control parameter group includes: Get the real-time required flow of the hydraulic pump; Based on the real-time required flow and the control parameter group, the motor speed n is calculated by table lookup and interpolation; According to the formula Calculate the hydraulic pump displacement q, where Q is the real-time required flow of the hydraulic pump.

8. A motor hydraulic pump control system, characterized in that: include: A real-time output pressure acquisition module is used to obtain the real-time output pressure of the hydraulic pump under the current operating conditions; A control parameter group calling module is used to call the control parameter group corresponding to the pressure interval to which the real-time output pressure belongs based on the real-time output pressure; wherein the control parameter group is obtained based on a parameter classification method and an offline data analysis method, and includes the theoretical output pressures of several hydraulic pumps, the highest motor hydraulic pump total efficiency corresponding to each hydraulic pump flow rate under each theoretical output pressure, and the motor speed and hydraulic pump displacement corresponding to the highest motor hydraulic pump total efficiency; A calculation module, used to obtain the real-time required flow of the hydraulic pump, and calculate the motor speed and the hydraulic pump displacement in combination with the control parameter group; A control module is used to control the motor and the hydraulic pump based on the motor speed and the hydraulic pump displacement.

9. A motor hydraulic pump control system, characterized in that: It includes a pressure sensor, a flow command input device and a controller; The pressure sensor is used to detect the real-time output pressure of the hydraulic pump under the current operating condition and send it to the controller; The flow command input device is used to input the real-time required flow under the current operating conditions and send it to the controller; The controller is configured to execute the method according to any one of claims 1-7.

10. An engineering machine, characterized in that: A motor hydraulic pump control system comprising the motor hydraulic pump control system according to any one of claims 8 or 9.

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