Control method and system of hydraulic system

Abstract

The invention relates to a control method and system for a hydraulic system, and the method comprises the steps: receiving a target output pressure and a target sliding distance, and determining the target feeding amount of the hydraulic system; the target feeding amount of the hydraulic system is fed back to the actual feeding amount of the hydraulic system, and the hydraulic system can adjust the output torque of the hydraulic system timely and sensitively. Inputting the target output pressure and the target sliding distance into a regulation and control function to obtain a first pressure value, a second pressure value, a first sliding length and a second sliding length of the regulation and control function, calling a steady-state function, receiving an input pressure matching curve of the steady-state function to the hydraulic system according to the first pressure value and the second pressure value, and according to the first sliding length and the second sliding length, an input length matching curve of the steady-state function to the hydraulic system is received. Based on the input pressure ratio curve and the input speed ratio curve, an adjusting program is executed on the hydraulic system, and the output torque of the hydraulic system can be effectively, timely and sensitively adjusted.

Description

Technical Field

[0001] The present application relates to the technical field of hydraulic systems, and in particular to a control method and system for a hydraulic system. Background Art

[0002] The function of the hydraulic system is to increase the force by changing the pressure. A complete hydraulic system consists of five parts, namely power elements, actuators, control elements, auxiliary elements and hydraulic media. Hydraulic systems can be divided into two categories: hydraulic transmission systems and hydraulic control systems. The main function of hydraulic transmission systems is to transmit power and motion. The hydraulic control system is to make the output of the hydraulic system meet specific performance requirements. The hydraulic system usually refers to the hydraulic transmission system.

[0003] Traditional hydraulic systems often adjust the output torque of the hydraulic system by changing the pressure of the pressure-transmitting medium. Hydraulic systems are often used in heavy-load working environments. There is a large medium pressure and medium pressure inside the hydraulic system, which makes it difficult for traditional hydraulic systems to adjust the output torque of the hydraulic system in a timely and sensitive manner. Therefore, it is necessary to propose a control method and system for a hydraulic system in view of the defect that traditional hydraulic systems are difficult to adjust the output torque of the hydraulic system in a timely and sensitive manner. Summary of the invention

[0004] Based on this, it is necessary to propose a control method and system for a hydraulic system to address the defect that the traditional hydraulic system is difficult to timely and sensitively adjust the output torque of the hydraulic system.

[0005] The present application provides a control method for a hydraulic system, comprising:

[0006] receiving a target output pressure and a target sliding distance;

[0007] Inputting the target output pressure and the target sliding distance into the control function;

[0008] Obtaining a first pressure value, a second pressure value, a first sliding length, and a second sliding length of a control function;

[0009] Call the steady-state function;

[0010] receiving a steady-state function to an input pressure matching curve of the hydraulic system according to the first pressure value and the second pressure value;

[0011] receiving a ratio curve of a steady-state function to an input length of a hydraulic system according to the first sliding length and the second sliding length;

[0012] Based on the input pressure ratio curve and the input speed ratio curve, a regulation procedure is performed on the hydraulic system.

[0013] The present application provides a control system for a hydraulic system, comprising:

[0014] A processor, used to execute the control method of the hydraulic system;

[0015] A first telescopic body, communicatively connected to the processor;

[0016] A second telescopic body, communicatively connected to the processor;

[0017] The hydraulic cylinder comprises a first input branch, a second input branch and an output branch, wherein the first telescopic body is arranged in the inner cavity of the first input branch, and the second telescopic body is arranged in the inner cavity of the second input branch.

[0018] The present application relates to a control method and system for a hydraulic system, which determines the target feed amount of the hydraulic system by receiving the target output pressure and the target sliding distance. The target feed amount of the hydraulic system is fed back to the actual feed amount of the hydraulic system, so that the hydraulic system can timely and sensitively adjust the output torque of the hydraulic system. The target output pressure and the target sliding distance are input into the control function to obtain the first pressure value, the second pressure value, the first sliding length, and the second sliding length of the control function, and the steady-state function is called. According to the first pressure value and the second pressure value, the input pressure ratio curve of the steady-state function to the hydraulic system is received, and according to the first sliding length and the second sliding length, the input length ratio curve of the steady-state function to the hydraulic system is received. Based on the input pressure ratio curve and the input speed ratio curve, the adjustment program is executed on the hydraulic system, which can effectively realize timely and sensitive adjustment of the output torque of the hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A flow chart of a control method for a hydraulic system provided in one embodiment of the present application.

[0020] Figure 2 A structural diagram of a control system of a hydraulic system provided in one embodiment of the present application.

[0021] Reference numerals:

[0022] 100-processor; 200-first telescopic body; 300-second telescopic body; 400-hydraulic cylinder;

[0023] 410 - first input branch; 420 - second input branch; 430 - output branch. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0025] The present application provides a control method for a hydraulic system.

[0026] like Figure 1 As shown, in one embodiment of the present application, a control method of a hydraulic system includes:

[0027] S100, receiving a target output pressure and a target sliding distance.

[0028] S200, inputting the target output pressure and the target sliding distance into the control function.

[0029] S300, obtaining a first pressure value, a second pressure value, a first sliding length, and a second sliding length of a control function.

[0030] S400, calling the steady-state function.

[0031] S500: Receive a steady-state function to an input pressure matching curve of a hydraulic system according to a first pressure value and a second pressure value.

[0032] S600: Receive a ratio curve of a steady-state function to an input length of a hydraulic system according to a first sliding length and a second sliding length.

[0033] S700: Execute a regulation procedure on the hydraulic system based on the input pressure ratio curve and the input speed ratio curve.

[0034] The present embodiment relates to a control method for a hydraulic system, which determines the target feed amount of the hydraulic system by receiving the target output pressure and the target sliding distance. The target feed amount of the hydraulic system is fed back to the actual feed amount of the hydraulic system, so that the hydraulic system can timely and sensitively adjust the output torque of the hydraulic system. The target output pressure and the target sliding distance are input into the control function to obtain the first pressure value, the second pressure value, the first sliding length, and the second sliding length of the control function, and the steady-state function is called. According to the first pressure value and the second pressure value, the input pressure ratio curve of the steady-state function to the hydraulic system is received, and according to the first sliding length and the second sliding length, the input length ratio curve of the steady-state function to the hydraulic system is received. Based on the input pressure ratio curve and the input speed ratio curve, the adjustment program is executed on the hydraulic system, which can effectively realize timely and sensitive adjustment of the output torque of the hydraulic system.

[0035] In one embodiment of the present application, S200 includes:

[0036] S210, receiving a first input cavity cross-sectional area, a second input cavity cross-sectional area, and an output cavity cross-sectional area.

[0037] S220, defining the first sliding length as an equivalent first reference amount.

[0038] S230, defining a second sliding length as an equivalent second reference amount.

[0039] S240: Define the target sliding distance as an equivalent third reference value.

[0040] S250, based on Pascal's law, generates a constant equation for the control function.

[0041] Specifically, the pressure generated in the first input cavity by a first pressure having a first pressure value can be determined based on the cross-sectional area of ​​the first input cavity using the first external pressure value. The pressure generated in the second input cavity by a second pressure having a second pressure value can be determined based on the cross-sectional area of ​​the second input cavity using the second external pressure value.

[0042] Since the internal pressure of the hydraulic medium of the hydraulic system is equal everywhere, the internal pressure of the hydraulic medium of the hydraulic system will change when the pressure applied and generated from the outside is received. This change is based on the transfer characteristics of the hydraulic medium, and can achieve continuous changes in the hydraulic system. Based on the comprehensive fluid mechanics coupling of the equivalent first reference quantity of the first input chamber, the equivalent second reference quantity of the second input chamber, the pressure generated by the first pressure in the first input chamber, and the pressure generated by the second pressure in the second input chamber, the hydraulic system can be adjusted timely and sensitively.

[0043] In one embodiment of the present application, S250 includes:

[0044] S251, create constant equations.

[0045] The constant equations include volume equations and pressure parameter equations.

[0046] The volume equation is shown in Formula 1:

[0047] L3·S3=L1·S1+L2·S2 Formula 1

[0048] Among them, L1 is the equivalent first reference quantity, S1 is the cross-sectional area of ​​the first input cavity, L2 is the equivalent second reference quantity, S2 is the cross-sectional area of ​​the second input cavity, L3 is the equivalent third reference quantity, and S3 is the cross-sectional area of ​​the output cavity.

[0049] Specifically, the volume equation based on Pascal's law is used in hydraulic media. Due to the fluidity of the hydraulic medium, the pressure change in a part of the static fluid in a closed container will be transmitted in all directions without changing its magnitude. The pressure is equal to the applied pressure divided by the area under force.

[0050] According to Pascal's law, a certain pressure on one piston in a hydraulic system will produce the same pressure increment on the other piston. If the area of ​​the second piston is 10 times that of the first piston, then the force acting on the second piston will increase to 10 times that of the first piston, and the pressure on the two pistons will be equal.

[0051] The pressure parameter equation is:

[0052]

[0053]

[0054] Among them, P1 is the medium pressure in the first input chamber, P2 is the medium pressure in the second input chamber, P3 is the medium pressure in the output chamber, F1 is the input pressure of the first input chamber, F2 is the input pressure of the second input chamber, F3 is the output pressure of the output chamber, p is the pressure corresponding to the target output pressure, C is the fitting resistance coefficient of the medium, C1 is the fitting resistance coefficient of the first input chamber, C2 is the fitting resistance coefficient of the second input chamber, P1(t) is the input pressure to the first input chamber, and P2(t) is the input pressure to the second input chamber.

[0055] Specifically, a progressive pressure parameter equation can be used for the input pressure of the first input chamber and the input pressure of the second input chamber. Based on Formula 3, the input stability of the medium pressure in the first input chamber and the medium pressure in the second input chamber can be achieved. In the process of stabilizing the input pressure, the constant hydraulic pressure of the hydraulic medium in Formula 2 can change smoothly.

[0056] The formal quantification of Formula 3, such as the formal quantification about the fitted resistance coefficient of the medium, can be modified based on the target output pressure and the target sliding distance to achieve timely and sensitive adjustment of the output torque of the hydraulic system.

[0057] In one embodiment of the present application, S200 further includes:

[0058] S261, the control function also includes a medium steady-state harmonic function.

[0059] The medium steady-state harmonic function is:

[0060]

[0061]

[0062] Among them, G1 is the transfer function of the input pressure of the first input chamber, G2 is the transfer function of the input pressure of the second input chamber, P1 is the medium pressure in the first input chamber, P2 is the medium pressure in the second input chamber, and p is the pressure corresponding to the target output pressure.

[0063] S262, combining Formula 1, Formula 2, Formula 3, Formula 4 and Formula 5 to obtain a control function.

[0064] Specifically, based on the pressure parameter equation, the transfer function of the input pressure of the first input chamber and the transfer function of the input pressure of the second input chamber can be realized to provide feedback on the medium pressure in the first input chamber and the medium pressure in the second input chamber, thereby realizing a stable, timely and sensitive adjustment of the hydraulic system.

[0065] Simply, by applying forces of different magnitudes, a stable, timely and sensitive adjustment of the hydraulic system can be achieved in a stable adjustment system.

[0066] In actual application, the transfer function of the input pressure of the first input chamber and the transfer function of the input pressure of the second input chamber can be used as the final limit time to determine, couple and adjust the steady-state process according to the target output pressure and the target sliding distance.

[0067] In one embodiment of the present application, S262 includes:

[0068] S262a, combining Formula 1, Formula 2, Formula 3, Formula 4 and Formula 5, to obtain a control function as shown in Formula 6:

[0069]

[0070] Specifically, in the control function, the qualitative relationship between the parameters of the target output pressure and the target sliding distance and the hydraulic system performance and steady-state performance can be used to adjust the parameters of the control function by experimental methods.

[0071] In order to reduce the parameters that need to be adjusted and ensure the safety of the system, conservative parameters can be set for the fitting resistance coefficient and transfer function at the beginning of debugging to avoid abnormal situations such as system instability or excessive overshoot.

[0072] According to the relationship between the parameters of the control function and the performance of the hydraulic system, repeatedly adjust the parameters of the fitting resistance coefficient and the transfer function. If the overshoot of the step response is too large, it takes many oscillations to stabilize or is not stable at all, reduce the fitting resistance coefficient. If there is no overshoot in the step response, but the controlled quantity rises too slowly and the transition process takes too long, the parameters should be adjusted in the opposite direction. If the speed of eliminating errors is slow, the parameters of the transfer function can be appropriately transferred to enhance the supplementary effect.

[0073] In one embodiment of the present application, S400 includes:

[0074] S411, obtaining a first-order partial differential derivative of a time parameter of a first pressure value in the control function.

[0075] S412, obtaining a pressure matching function of the first pressure value with respect to time.

[0076] S413, obtaining a first-order partial differential derivative of a time parameter of the second pressure value in the control function.

[0077] S414, obtaining a pressure matching function of the second pressure value with respect to time.

[0078] Specifically, in general, by taking the first-order partial differential derivative of the time parameter of the first pressure value in the control function, the pressure ratio function of the first pressure value with respect to time can be obtained. Similarly, by taking the first-order partial differential derivative of the time parameter of the second pressure value in the control function, the pressure ratio function of the second pressure value with respect to time can be obtained.

[0079] The pressure ratio function of the first pressure value with respect to time and the pressure ratio function of the second pressure value with respect to time can be used as a linkage relationship function between the target output pressure and the target sliding distance in actual coupling regulation.

[0080] S421, defining a motion model corresponding to the first sliding length as a uniform speed motion model.

[0081] S422, assigning a value of zero to the pressure matching function of the first pressure value with respect to time.

[0082] S423, obtaining a duration value of the first pressure value.

[0083] S424, assigning a value of zero to the pressure matching function of the second pressure value with respect to time.

[0084] S425, obtaining a duration value of the second pressure value.

[0085] Specifically, in a model where the motion model corresponding to the first sliding length is a uniform motion model, the moving parts of the hydraulic system can be used as uniform reciprocating and linear motion moving parts. In this embodiment, since the overall pressure value of the hydraulic system is relatively large, uniform reciprocating and linear motion can be selected.

[0086] Relying on the motion model, the pressure ratio function of the first pressure value with respect to time is assigned a value of zero, and the pressure ratio function of the second pressure value with respect to time is assigned a value of zero, so as to determine the duration value of the first pressure value and the duration value of the second pressure value.

[0087] In one embodiment of the present application, S500 includes:

[0088] S510, incorporating the duration value of the first pressure value into Formula 3.

[0089] S520, incorporate Formula 3 into Formula 2.

[0090] S530, obtaining an input pressure ratio curve of the first pressure value.

[0091] S540, obtaining an input pressure matching curve of a second pressure value.

[0092] Specifically, the duration value of the first pressure value is incorporated into Formula 3 to obtain a function of the input pressure of the first input chamber, and an input pressure ratio curve of the first pressure value can be obtained based on the function of the input pressure of the first input chamber.

[0093] S550, incorporating the duration value of the first pressure value into Formula 3 and Formula 4 to obtain an equivalent first reference value.

[0094] S560, incorporating the duration value of the second pressure value into Formula 3 and Formula 5 to obtain an equivalent second reference value.

[0095] S570, incorporating the equivalent first reference amount and the equivalent second reference amount into Formula 6.

[0096] S580: Obtain an input length ratio curve of the hydraulic system.

[0097] Specifically, the duration value of the first pressure value is incorporated into Formula 3 and Formula 4 to obtain a function of an equivalent first reference quantity. Based on the function of the equivalent first reference quantity, based on the comprehensive fluid mechanics coupling of the equivalent first reference quantity of the first input chamber, the equivalent second reference quantity of the second input chamber, the pressure generated by the first pressure in the first input chamber, and the pressure generated by the second pressure in the second input chamber, the hydraulic system can be timely and sensitively adjusted.

[0098] The present application provides a control system for a hydraulic system.

[0099] like Figure 2 As shown, in one embodiment of the present application, a control system of a hydraulic system includes:

[0100] The processor 100 is used to execute the control method of the hydraulic system mentioned in any one of the embodiments.

[0101] The first telescopic body 200 is in communication connection with the processor 100 .

[0102] The second telescopic body 300 is in communication connection with the processor 100 .

[0103] The hydraulic cylinder 400 includes a first input branch 410 , a second input branch 420 and an output branch 430 . The first telescopic body 200 is disposed in the inner cavity of the first input branch 410 , and the second telescopic body 300 is disposed in the inner cavity of the second input branch 420 .

[0104] The present embodiment relates to a control system of a hydraulic system. The processor 100 determines the target feed amount of the first telescopic body 200 and the target feed amount of the second telescopic body 300 of the hydraulic system by receiving the target output pressure and the target sliding distance. The first telescopic body 200 is arranged in the inner cavity of the first input branch 410, and the second telescopic body 300 is arranged in the inner cavity of the second input branch 420. The target feed amount of the hydraulic system is fed back to the actual feed amount of the hydraulic system, so that the hydraulic system can timely and sensitively adjust the output torque of the hydraulic system. The target output pressure and the target sliding distance are input into the control function to obtain the first pressure value, the second pressure value, the first sliding length, and the second sliding length of the control function, and the steady-state function is called. According to the first pressure value and the second pressure value, the input pressure ratio curve of the steady-state function to the hydraulic system is received, and according to the first sliding length and the second sliding length, the input length ratio curve of the steady-state function to the hydraulic system is received. Based on the input pressure ratio curve and the input speed ratio curve, the adjustment program is executed on the hydraulic system, which can effectively realize the timely and sensitive adjustment of the output torque of the hydraulic system.

[0105] The technical features of the above-described embodiments can be combined arbitrarily, and the execution order of each method step is not limited. In order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. The above-described embodiments only express several implementation methods of the present application, and the description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the patent of this application. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several deformations and improvements can be made, which all belong to the scope of protection of the present application. Therefore, the scope of protection of the present application shall be based on the attached claims.

Claims

1. A control method for a hydraulic system, characterized in that: include: receiving a target output pressure and a target sliding distance; Inputting the target output pressure and the target sliding distance into the control function; Obtaining a first pressure value, a second pressure value, a first sliding length, and a second sliding length of a control function; Call the steady-state function; receiving a steady-state function to an input pressure matching curve of the hydraulic system according to the first pressure value and the second pressure value; receiving a ratio curve of a steady-state function to an input length of a hydraulic system according to the first sliding length and the second sliding length; Based on the input pressure ratio curve and the input speed ratio curve, a regulation procedure is performed on the hydraulic system.

2. The control method of the hydraulic system according to claim 1, characterized in that: The inputting the target output pressure and the target sliding distance into the control function comprises: Receiving a first input cavity cross-sectional area, a second input cavity cross-sectional area, and an output cavity cross-sectional area; Define the first sliding length as the equivalent first reference quantity; defining the second sliding length as an equivalent second reference quantity; Define the target sliding distance as the equivalent third reference quantity; Based on Pascal's law, a constant equation for the control function is generated.

3. The control method of the hydraulic system according to claim 2, characterized in that: The constant equation of the control function is generated based on Pascal's law, including the control function: the control function includes a constant equation; the constant equation includes a volume equation and a pressure parameter equation; The volume equation is: L3·S3=L1·S1+L2·S2 Formula 1; Wherein, L1 is the equivalent first reference quantity, S1 is the cross-sectional area of ​​the first input cavity, L2 is the equivalent second reference quantity, S2 is the cross-sectional area of ​​the second input cavity, L3 is the equivalent third reference quantity, S3 is the cross-sectional area of ​​the output cavity; The pressure parameter equation is: p(t)=p·(C·e r +1) Among them, P1 is the medium pressure in the first input chamber, P2 is the medium pressure in the second input chamber, P3 is the medium pressure in the output chamber, F1 is the input pressure of the first input chamber, F2 is the input pressure of the second input chamber, F3 is the output pressure of the output chamber, P is the pressure corresponding to the target output pressure, C is the fitting resistance coefficient of the medium, C1 is the fitting resistance coefficient of the first input chamber, C2 is the fitting resistance coefficient of the second input chamber, P1(t) is the input pressure to the first input chamber, and P2(t) is the input pressure to the second input chamber.

4. The control method of the hydraulic system according to claim 3, characterized in that: The target output pressure and the target sliding distance are input into the control function, which also includes: A medium steady-state harmonic function is created; the medium steady-state harmonic function is shown in Formula 4 and Formula 5: Wherein, G1 is the transfer function of the input pressure of the first input chamber, G2 is the transfer function of the input pressure of the second input chamber, P1 is the medium pressure in the first input chamber, P2 is the medium pressure in the second input chamber, and P is the pressure corresponding to the target output pressure; By combining Formula 1, Formula 2, Formula 3, Formula 4 and Formula 5, the control function is obtained.

5. The control method of the hydraulic system according to claim 4, characterized in that: The control function is obtained by combining Formula 1, Formula 2, Formula 3, Formula 4 and Formula 5, including: By combining Formula 1, Formula 2, Formula 3, Formula 4 and Formula 5, we can obtain the control function shown in Formula 6:

6. The control method of the hydraulic system according to claim 5, characterized in that: The calling of the steady-state function comprises: Calculating a first-order partial differential derivative of a time parameter of a first pressure value in the control function to obtain a pressure ratio function of the first pressure value with respect to time; A first-order partial differential derivative is calculated for the time parameter of the second pressure value in the control function to obtain a pressure matching function of the second pressure value with respect to time.

7. The control method of the hydraulic system according to claim 6, characterized in that: The calling of the steady-state function comprises: Define the motion model corresponding to the first sliding length as a uniform speed motion model; Assigning a value of zero to the pressure matching function of the first pressure value with respect to time, to obtain a duration value of the first pressure value; The value of zero is assigned to the pressure matching function of the second pressure value with respect to time, so as to obtain the duration value of the second pressure value.

8. The control method of the hydraulic system according to claim 7, characterized in that: The step of receiving a steady-state function to an input pressure matching curve of the hydraulic system according to the first pressure value and the second pressure value comprises: The duration value of the first pressure value is incorporated into Formula 3; Incorporate Formula 3 into Formula 2; Obtaining an input pressure ratio curve of a first pressure value; An input pressure matching curve of a second pressure value is obtained.

9. The control method of the hydraulic system according to claim 8, characterized in that: The step of receiving a ratio curve of a steady-state function to an input length of a hydraulic system according to the first sliding length and the second sliding length comprises: The duration value of the first pressure value is incorporated into Formula 3 and Formula 4 to obtain an equivalent first reference value; The duration value of the second pressure value is incorporated into Formula 3 and Formula 5 to obtain an equivalent second reference value; The equivalent first reference quantity and the equivalent second reference quantity are incorporated into formula 6; Obtain the input length ratio curve of the hydraulic system.

10. A control system for a hydraulic system, characterized in that: include: A processor, configured to execute the control method of the hydraulic system according to any one of claims 1 to 9; A first telescopic body, communicatively connected to the processor; A second telescopic body, communicatively connected to the processor; The hydraulic cylinder comprises a first input branch, a second input branch and an output branch, wherein the first telescopic body is arranged in the inner cavity of the first input branch, and the second telescopic body is arranged in the inner cavity of the second input branch.

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