Displacement control system for hydraulic valve control actuator

Abstract

The invention provides a hydraulic valve control actuator displacement control system. The hydraulic valve control actuator displacement control system comprises an actuator, a valve, an actuator controller, a valve controller, a flow sensor and a valve element displacement sensor. According to the displacement control system for the hydraulic valve-controlled actuator, displacement control over the actuator and displacement control over the valve element are achieved through the two-stage controller, and high control precision is achieved; through closed-loop control of the two-stage controller, the control precision is high; compared with a displacement sensor in the prior art, the flow sensor indirectly determines the displacement of the actuator by collecting the flow data, the anti-pollution capacity is high, the flow sensor is more suitable for being applied to the external high-pollution environment such as a jumbolter, and compared with an external displacement sensor, the flow sensor has the advantage of being small in occupied space; the method is suitable for a size-limited environment and has better compatibility.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic equipment, and in particular to a displacement control system of a hydraulic valve-controlled actuator. Background Art

[0002] With the continuous deepening of intelligence in the coal machinery industry and the engineering machinery industry, the upper-level perception and decision-making systems are relatively complete, but the underlying motion control system is in urgent need of upgrading, which is reflected in the fact that the motion control of mid- and low-end models is basically extensive open-loop control, which is difficult to achieve automation and intelligence. Taking the anchor drilling rig as an example, in order to achieve certain process action automation, its drilling rig lifting channel has the need for precise control of displacement and force, and the current open-loop hydraulic control system is difficult to meet the needs of automated processes. However, due to the compact size and space of the anchor drilling rig, the small size of the oil cylinder and the highly polluted external environment, the technical solution of the external displacement sensor has not been listed as an engineering solution by the OEM.

[0003] In the prior art, to realize the displacement closed loop of the valve-controlled actuator, it is usually necessary to install a magnetostrictive displacement sensor in the hydraulic cylinder, or an external pull-wire sensor to collect the linear displacement of the actuator, and to install an angle sensor at the joint to collect the angular displacement. However, due to different environmental requirements and dimensional space requirements, not all actuators have sufficient installation space reserved near them, and the pull-wire sensor has very poor anti-pollution ability and is rarely used in actual industrial production. On a few rotary joints, the layout of the external angle sensor also faces considerable anti-pollution and protection difficulties. Summary of the invention

[0004] The main purpose of the present invention is to provide a hydraulic valve-controlled actuator displacement control system to solve at least one of the technical problems in the prior art that the installation of linear or angular displacement sensors on valve-controlled actuators is limited by environmental requirements and installation space requirements.

[0005] In order to achieve the above-mentioned purpose, according to the present invention, a hydraulic valve-controlled actuator displacement control system is provided, comprising an actuator, a valve, an actuator controller, a valve controller, a flow sensor, and a valve core displacement sensor, wherein the valve is connected to the actuator, the valve controller is connected to the valve, and the actuator controller is connected to the valve controller; the actuator controller outputs a first valve core displacement instruction to the valve controller based on a first actuator displacement instruction and an inflow / outflow flow of the actuator; the valve core displacement sensor collects valve core displacement samples of the valve and feeds them back to the valve controller; the valve controller outputs valve core control parameters to the valve based on the first valve core displacement instruction and the valve core displacement samples; the flow sensor collects the inflow / outflow flow and feeds it back to the actuator controller.

[0006] Furthermore, the actuator controller includes a first instruction generator, an actuator displacement controller, and a flow / displacement conversion module, wherein the inflow / outflow flow is converted into an actuator displacement sampling based on an actuator model; the actuator displacement sampling is converted into a first initialization parameter based on an actuator / load dynamic model; the first instruction generator outputs a second actuator displacement instruction to the actuator displacement controller based on the first actuator displacement instruction and the first initialization parameter; the actuator displacement controller outputs a valve core flow instruction based on the load force, the second actuator displacement instruction, and the actuator displacement sampling; and the flow / displacement conversion module converts the valve core flow instruction into the first valve core displacement instruction based on a proportional valve model.

[0007] Furthermore, the valve controller includes a second instruction generator and a valve displacement controller, the proportional valve model serves as a second initialization parameter, the second instruction generator outputs a second valve core displacement instruction to the valve displacement controller based on the first valve core displacement instruction and the second initialization parameter; the valve displacement controller outputs the valve core control parameter based on the second valve core displacement instruction and the valve core displacement sampling.

[0008] Furthermore, the actuator displacement controller includes a displacement controller, a speed controller, and a differential filter. The displacement controller outputs a speed instruction based on the second actuator displacement instruction, the actuator model, the proportional valve model, and the actuator displacement sampling; the differential filter converts the actuator displacement sampling into a speed sampling; and the speed controller outputs the valve core flow instruction based on the speed instruction and the speed sampling.

[0009] Furthermore, the actuator model includes a cylinder model, and the cylinder model expression is:

[0010]

[0011] A is the area of ​​the cylinder, x p is the displacement of the cylinder, v p is the cylinder speed.

[0012] Furthermore, the actuator model includes a motor model, and the motor model expression is:

[0013]

[0014] D is the motor displacement, θ p is the motor angle, ω p is the motor speed.

[0015] Furthermore, the proportional valve model includes a valve core flow equation, and the valve core flow equation is:

[0016]

[0017] C d is the flow coefficient, w is the valve port working chamber area gradient, x v is the valve core opening, △P is the pressure difference between the valve inlet and outlet, and ρ is the fluid density.

[0018] Furthermore, the proportional valve model includes a valve core opening equation, and the valve core opening equation is:

[0019]

[0020] is the input corresponding to the dead zone of the valve core, k is the coefficient of input-proportional valve core displacement, u is the input control amount, x v is the valve core opening.

[0021] Furthermore, the first instruction generator includes a ramp generator and / or a filter.

[0022] Furthermore, the second instruction generator includes a ramp generator and / or a filter.

[0023] The hydraulic valve-controlled actuator displacement control system in the present invention realizes the displacement control of the actuator and the displacement control of the valve core through a two-stage controller of an actuator controller and a valve controller, and has high control accuracy; a flow sensor is used as feedback of the actuator controller, and a valve core displacement sensor is used as feedback of the valve controller, so a closed-loop control of the two-stage controller is formed, and has high control accuracy; compared with the displacement sensor in the traditional technology, the flow sensor used in the present invention indirectly determines the displacement of the actuator by collecting flow data. The flow sensor is usually arranged in a cavity with a certain protection level, has strong anti-pollution ability, and is more suitable for application in external high-pollution environments such as anchor drilling rigs, and has the advantage of occupying less space than an external displacement sensor, is suitable for size-restricted environments, and has better compatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 A structural block diagram of a displacement control system of a hydraulic valve-controlled actuator provided in an embodiment of the present invention;

[0026] Figure 2 The second structural block diagram of the displacement control system of the hydraulic valve-controlled actuator provided by the embodiment of the present invention;

[0027] Figure 3The third structural block diagram of the hydraulic valve-controlled actuator displacement control system provided in the embodiment of the present invention.

[0028] The above drawings include the following reference numerals:

[0029] 1. Actuator; 2. Valve; 3. Actuator controller; 31. First instruction generator; 32. Actuator displacement controller; 321. Displacement controller; 322. Speed ​​controller; 323. Differential filter; 33. Flow / displacement conversion module; 4. Valve controller; 41. Second instruction generator; 42. Valve displacement controller; 5. Flow sensor; 6. Valve core displacement sensor. DETAILED DESCRIPTION

[0030] 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, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. 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.

[0031] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0032] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0033] The present invention provides a hydraulic valve-controlled actuator displacement control system, comprising an actuator 1, a valve 2, an actuator controller 3, a valve controller 4, a flow sensor 5, and a valve core displacement sensor 6, wherein the valve 2 is connected to the actuator 1, the valve controller 4 is connected to the valve 2, and the actuator controller 3 is connected to the valve controller 4; the actuator controller 3 outputs a first valve core displacement instruction to the valve controller 4 based on a first actuator displacement instruction and an inflow / outflow flow of the actuator 1; the valve core displacement sensor 6 collects a valve core displacement sample of the valve 2 and feeds it back to the valve controller 4; the valve controller 4 outputs a valve core control parameter to the valve 2 based on the first valve core displacement instruction and the valve core displacement sample; the flow sensor 5 collects the inflow / outflow flow and feeds it back to the actuator controller 3.

[0034] Combination Figure 1 As shown, each box in the figure represents the corresponding structure in the displacement control system of the hydraulic valve-controlled actuator. The actuator 1 can use corresponding components as needed, such as a cylinder, a motor, etc. The actuator controller 3 collects the displacement command of the first actuator and the inflow / outflow flow ( Figure 1 The input end of the flow sensor is connected between the valve 2 and the actuator 1, which realizes the collection of the inflow flow of the actuator 1; when the input end of the flow sensor is connected to the output end of the actuator 1, the collection of the outflow flow of the actuator 1 is realized), the actuator controller 3 outputs the first valve core displacement instruction, the inflow / outflow flow is related to the actuator displacement, therefore, the inflow / outflow flow here is actually used as the actuator displacement sampling, that is, the control target of the actuator controller 3 here is to make the actuator displacement sampling follow the first actuator displacement instruction; the valve controller 4 collects the first valve core displacement instruction and the valve core displacement sampling (the valve core displacement sampling is collected through the valve core displacement sensor 6), and then outputs the valve core control parameters to the valve 2, the valve core control parameters include the control voltage, current value and other parameters of the valve core, the actuator 1 generates an action displacement under the pressure control, flow, inertia load and external load of the valve 2.

[0035] The hydraulic valve-controlled actuator displacement control system in the present invention realizes the displacement control of the actuator and the displacement control of the valve core through the two-stage controller of the actuator controller 3 and the valve controller 4, and has high control accuracy; the flow sensor 5 is used as the feedback of the actuator controller 3, and the valve core displacement sensor 6 is used as the feedback of the valve controller 4, so as to form a closed-loop control of the two-stage controller, which has high control accuracy; compared with the displacement sensor in the traditional technology, the flow sensor 5 used in the present invention indirectly determines the displacement of the actuator by collecting flow data. The flow sensor 5 is usually arranged in a cavity with a certain protection level, has strong anti-pollution ability, and is more suitable for application in external high-pollution environments such as anchor drilling rigs, and has the advantage of occupying less space than external displacement sensors, is suitable for size-constrained environments, and has better compatibility.

[0036] Furthermore, the actuator controller 3 includes a first instruction generator 31, an actuator displacement controller 32, and a flow / displacement conversion module 33. The inflow / outflow flow is converted into an actuator displacement sampling based on the actuator model; the actuator displacement sampling is converted into a first initialization parameter based on the actuator / load dynamic model; the first instruction generator 31 outputs a second actuator displacement instruction to the actuator displacement controller 32 based on the first actuator displacement instruction and the first initialization parameter; the actuator displacement controller 32 outputs a valve core flow instruction based on the load force, the second actuator displacement instruction, and the actuator displacement sampling; the flow / displacement conversion module 33 converts the valve core flow instruction into the first valve core displacement instruction based on the proportional valve model.

[0037] Combination Figure 2 As shown, Figure 2 yes Figure 1 The subdivision of the actuator controller 3 and the valve controller 4 (actuator 1 at Figure 2 (not shown), the actuator displacement sampling is converted into the first initialization parameter based on the actuator / load dynamic model, and the inflow / outflow flow is converted into the actuator displacement sampling according to the actuator model. The first instruction generator 31 preferably includes a ramp generator and / or a filter, and then the first instruction generator 31 can output a discrete instruction signal according to a set rule, so as to constrain the discrete instruction signal of an input device such as a rocker, a switch, etc. to within the physical limit. In this embodiment, the first actuator displacement instruction is processed by the first instruction generator 31 and output as the second actuator displacement instruction. The actuator displacement controller 32 outputs the valve core flow instruction according to the load force, the second actuator displacement instruction, and the actuator displacement sampling. The flow / displacement conversion module 33 considers the proportional valve model (the valve core displacement / flow relationship of the proportional valve), thereby converting the valve core flow instruction into the first valve core displacement instruction (that is, the valve core flow is converted into the valve core displacement), thereby realizing the closed-loop control of the actuator displacement control.

[0038] In this way, the discrete command signal is constrained to within the physical limit through the first command generator 31, so as to realize functions such as signal normalization, slope generation, constraint protection, etc., thereby improving the stability of the control system. The actuator displacement controller 32 outputs the valve core flow command according to the actuator displacement sampling, load force, and the second actuator displacement command. The valve core flow command is converted into the first valve core displacement command through the flow / displacement conversion module 33, thereby realizing closed-loop control of the actuator displacement with higher control accuracy.

[0039] Furthermore, the valve controller 4 includes a second instruction generator 41 and a valve displacement controller 42. The proportional valve model serves as a second initialization parameter. The second instruction generator 41 outputs a second valve core displacement instruction to the valve displacement controller 42 based on the first valve core displacement instruction and the second initialization parameter; the valve displacement controller 42 outputs the valve core control parameter based on the second valve core displacement instruction and the valve core displacement sampling.

[0040] Combination Figure 2 As shown, the second command generator 41 considers the proportional valve model to constrain the output of the actuator displacement controller 32, and converts the first valve core displacement command into the second valve core displacement command. The second command generator 41 preferably includes a ramp generator and / or a filter. The discrete command signal is output according to the set rules and constrained to within the physical limit. The valve displacement controller 42 combines the valve core displacement sampling and the second valve core displacement command to output the valve core control parameters (i.e., the control voltage, current and other parameters of the valve core).

[0041] In this way, the discrete command signal is constrained to within the physical limit through the second command generator 41, so as to realize functions such as signal normalization, slope generation, constraint protection, etc., thereby improving the stability of the control system. The valve displacement controller 42 outputs the valve core control parameters according to the valve core displacement sampling and the second valve core displacement command, thereby realizing closed-loop control of the valve core displacement with higher control accuracy.

[0042] Furthermore, the actuator displacement controller 32 includes a displacement controller 321, a speed controller 322, and a differential filter 323. The displacement controller 321 outputs a speed instruction based on the second actuator displacement instruction, the actuator model, the proportional valve model and the actuator displacement sampling; the differential filter 323 converts the actuator displacement sampling into a speed sampling; and the speed controller 322 outputs the valve core flow instruction based on the speed instruction and the speed sampling.

[0043] Combination Figure 3 As shown, Figure 3 for Figure 2The actuator displacement controller 32 is subdivided (the valve controller 4 and valve 2 are not shown in the figure), and the inflow / outflow flow is converted into the actuator displacement sampling according to the actuator model. The displacement controller 321 outputs the speed instruction according to the actuator displacement sampling, the second actuator displacement instruction and the actuator model and the proportional valve model. The actuator displacement sampling first passes through the differential filter to convert the discrete flow signal into a speed sampling signal. The speed sampling is input into the speed controller 322, so that the speed controller 322 outputs the valve core flow instruction, that is, the desired valve core flow output, and then the flow / displacement conversion module converts the valve core flow instruction into the first valve core displacement instruction according to the proportional valve model.

[0044] In this way, the actuator displacement controller 32 forms a two-level closed-loop cascade control system with two control loops (i.e., the displacement loop corresponding to the displacement controller 321 and the speed loop corresponding to the speed controller 322), effectively avoiding the overshoot problem that may exist in the displacement controller 321 with a simple PID implementation.

[0045] Furthermore, the actuator model includes a cylinder model, and the cylinder model expression is:

[0046]

[0047] A is the area of ​​the cylinder, x p is the displacement of the cylinder, v p is the cylinder speed;

[0048] The actuator model includes a motor model, and the motor model expression is:

[0049]

[0050] D is the motor displacement, θ p is the motor angle, ω p is the motor speed.

[0051] In this way, the displacement / speed, displacement / flow rate, etc. of the actuator can be transformed according to the motor model and the cylinder model.

[0052] Furthermore, the proportional valve model includes a valve core flow equation, and the valve core flow equation is:

[0053]

[0054] C d is the flow coefficient, w is the valve port working chamber area gradient, x v is the valve core opening, △P is the pressure difference between the inlet and outlet of the valve port, and ρ is the fluid density;

[0055] The proportional valve model includes a valve core opening equation, which is:

[0056]

[0057] is the input corresponding to the dead zone of the valve core, k is the coefficient of input-proportional valve core displacement, u is the input control amount, x v is the valve core opening.

[0058] In this way, according to the above-mentioned proportional valve model, the transformation of valve displacement / flow rate etc. can be realized.

[0059] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0060] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A hydraulic valve-controlled actuator displacement control system, characterized in that: Including actuator, valve, actuator controller, valve controller, flow sensor, valve core displacement sensor, The valve is connected to the actuator, the valve controller is connected to the valve, and the actuator controller is connected to the valve controller; The actuator controller outputs a first valve core displacement instruction to the valve controller based on the first actuator displacement instruction and the inflow / outflow flow of the actuator; The valve core displacement sensor collects the valve core displacement samples of the valve and feeds back to the valve controller; The valve controller outputs a valve core control parameter to the valve based on the first valve core displacement instruction and the valve core displacement sampling; The flow sensor collects the inflow / outflow flow and feeds back the flow to the actuator controller.

2. The hydraulic valve-controlled actuator displacement control system according to claim 1, characterized in that: The actuator controller includes a first instruction generator, an actuator displacement controller, and a flow / displacement conversion module. The inflow / outflow flow is converted into actuator displacement sampling based on the actuator model; The actuator displacement sampling is converted into a first initialization parameter based on an actuator / load dynamics model; The first instruction generator outputs a second actuator displacement instruction to the actuator displacement controller based on the first actuator displacement instruction and the first initialization parameter; The actuator displacement controller outputs a valve core flow command based on the load force, the second actuator displacement command, and the actuator displacement sampling; The flow / displacement conversion module converts the valve core flow command into the first valve core displacement command based on a proportional valve model.

3. The hydraulic valve-controlled actuator displacement control system according to claim 2, characterized in that: The valve controller includes a second instruction generator and a valve displacement controller. The proportional valve model is used as a second initialization parameter, and the second instruction generator outputs a second valve core displacement instruction to the valve displacement controller based on the first valve core displacement instruction and the second initialization parameter; The valve displacement controller outputs the valve core control parameter based on the second valve core displacement instruction and the valve core displacement sample.

4. The hydraulic valve-controlled actuator displacement control system according to claim 3, characterized in that: The actuator displacement controller includes a displacement controller, a speed controller, and a differential filter. The displacement controller outputs a speed instruction based on the second actuator displacement instruction, the actuator model, the proportional valve model and the actuator displacement sampling; The differential filter converts the actuator displacement samples into velocity samples; The speed controller outputs the valve core flow rate instruction based on the speed instruction and the speed sampling.

5. The hydraulic valve-controlled actuator displacement control system according to claim 2, characterized in that: The actuator model includes a cylinder model, and the cylinder model expression is: A is the area of ​​the cylinder, x p is the displacement of the cylinder, v p is the cylinder speed.

6. The hydraulic valve-controlled actuator displacement control system according to claim 2, characterized in that: The actuator model includes a motor model, and the motor model expression is: D is the motor displacement, θ p is the motor angle, ω p is the motor speed.

7. The hydraulic valve-controlled actuator displacement control system according to claim 2, characterized in that: The proportional valve model includes a valve core flow equation, which is: C d is the flow coefficient, w is the valve port working chamber area gradient, x v is the valve core opening, ΔP is the pressure difference between the valve inlet and outlet, and ρ is the fluid density.

8. The hydraulic valve-controlled actuator displacement control system according to claim 2, characterized in that: The proportional valve model includes a valve core opening equation, which is: is the input corresponding to the dead zone of the valve core, k is the coefficient of input-proportional valve core displacement, u is the input control amount, x v is the valve core opening.

9. The hydraulic valve-controlled actuator displacement control system according to claim 2, characterized in that: The first instruction generator includes a ramp generator and / or a filter.

10. The hydraulic valve-controlled actuator displacement control system according to claim 3, characterized in that: The second instruction generator includes a ramp generator and / or a filter.

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