A hydraulic valve-controlled actuator displacement control system

Abstract

This invention provides a hydraulic valve-controlled actuator displacement control system, including an actuator, a valve, an actuator controller, a valve controller, a flow sensor, and a valve core displacement sensor. The hydraulic valve-controlled actuator displacement control system of this invention achieves actuator displacement control and valve core displacement control through a two-stage controller, resulting in high control accuracy. The closed-loop control of the two-stage controller also provides high control accuracy. Compared to displacement sensors in traditional technologies, the flow sensor in this invention indirectly determines the actuator displacement by collecting flow data, exhibiting stronger resistance to contamination and making it more suitable for high-pollution external environments such as anchor drilling rigs. Furthermore, compared to external displacement sensors, it has the advantage of smaller footprint, making it suitable for size-constrained environments and offering better compatibility.

Description

Technical Field

[0001] This invention relates to the field of hydraulic equipment technology, and more specifically, to a displacement control system for a hydraulic valve-controlled actuator. Background Technology

[0002] As the coal mining machinery and construction machinery industries continue to deepen their intelligentization, while upper-level perception and decision-making systems are relatively complete, the underlying motion control systems urgently need upgrading. This is evident in the fact that motion control in low- and mid-range models is essentially a crude open-loop control system, making automation and intelligence difficult to achieve. Taking anchor drilling rigs as an example, to achieve certain levels of process automation, the rig's lifting channel requires precise control of displacement and force. Current open-loop hydraulic control systems are insufficient to meet the demands of automated processes. Furthermore, due to the compact size of anchor drilling rigs, small-sized hydraulic cylinders, and the highly polluted external environment, the technology of external displacement sensors has not been included in the engineering plans of OEMs.

[0003] In existing technologies, achieving closed-loop displacement control in valve-controlled actuators typically requires the use of magnetostrictive displacement sensors installed in the hydraulic cylinder, or external wire sensors to collect linear displacement of the actuator, and angle sensors installed at the joints to collect angular displacement. However, due to varying environmental and space requirements, sufficient installation space is not always available near all actuators, and wire sensors have very poor resistance to contamination, resulting in their limited use in actual industrial production. On a few rotary joints, the placement of external angle sensors also faces significant challenges in terms of contamination resistance and protection. Summary of the Invention

[0004] The main objective of this invention is to provide a displacement control system for a hydraulic valve-controlled actuator, thereby solving at least one of the technical problems in the prior art, such as the limitation of installing linear or angular displacement sensors on valve-controlled actuators by environmental and installation space requirements.

[0005] To achieve the above objectives, the present invention provides a hydraulic valve-controlled actuator displacement control system, comprising an actuator, a valve, an actuator controller, a valve controller, a flow sensor, and a 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 command to the valve controller based on a first actuator displacement command and the inflow / outflow rate 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 command and the valve core displacement samples. The flow sensor collects the inflow / outflow rate and feeds it back to the actuator controller.

[0006] Furthermore, the actuator controller includes a first command 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 first initialization parameters based on the actuator / load dynamics model; the first command generator outputs a second actuator displacement command to the actuator displacement controller based on the first actuator displacement command and the first initialization parameters; 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.

[0007] Furthermore, the valve controller includes a second command generator and a valve displacement controller. The proportional valve model serves as a second initialization parameter. The second command generator outputs a second valve core displacement command to the valve displacement controller based on the first valve core displacement command and the second initialization parameter. The valve displacement controller outputs the valve core control parameters based on the second valve core displacement command 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 command based on the second actuator displacement command, the actuator model, the proportional valve model, and the actuator displacement sampling. The differential filter converts the actuator displacement sampling into speed sampling. The speed controller outputs the valve core flow command based on the speed command and the speed sampling.

[0009] Furthermore, the actuator model includes a hydraulic cylinder model, the expression of which is:

[0010]

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

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

[0013]

[0014] D is the motor displacement, θ p For the motor angle, ω p This refers to the motor speed.

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

[0016]

[0017] C d Here, is the flow coefficient, w is the gradient of the working chamber area of ​​the valve orifice, and x is... v ρ is the valve core opening, ΔP 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, which is:

[0019]

[0020] This refers to the input quantity corresponding to the valve core dead zone, where k is the coefficient of the input quantity minus the proportional valve core displacement, u is the input control quantity, and x is the input control quantity. v This refers to 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 of this invention achieves actuator displacement control and valve core displacement control through a two-stage controller consisting of an actuator controller and a valve controller, resulting in high control accuracy. By using a flow sensor as feedback for the actuator controller and a valve core displacement sensor as feedback for the valve controller, a closed-loop control system is formed, further enhancing control accuracy. Compared to displacement sensors in traditional technologies, the flow sensor used in this invention indirectly determines the actuator displacement by collecting flow data. Flow sensors are typically housed in a cavity with a certain level of protection, offering strong resistance to contamination and making them more suitable for high-pollution external environments such as anchor drilling rigs. Furthermore, compared to external displacement sensors, they occupy less space, making them suitable for size-constrained environments and providing better compatibility. Attached Figure Description

[0024] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0025] Figure 1 One of the structural block diagrams of the hydraulic valve-controlled actuator displacement control system provided in the embodiments of the present invention;

[0026] Figure 2 A second structural block diagram of the hydraulic valve-controlled actuator displacement control system provided in an 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 figures include the following reference numerals:

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

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0032] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0033] This invention provides a hydraulic valve-controlled actuator displacement control system, including 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. 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 command to the valve controller 4 based on a first actuator displacement command and the inflow / outflow rate of the actuator 1. The valve core displacement sensor 6 collects the valve core displacement sample of the valve 2 and feeds it back to the valve controller 4. The valve controller 4 outputs valve core control parameters to the valve 2 based on the first valve core displacement command and the valve core displacement sample. The flow sensor 5 collects the inflow / outflow rate and feeds it back to the actuator controller 3.

[0034] Combination Figure 1 As shown in the figure, each box represents a corresponding structure in the hydraulic valve-controlled actuator displacement control system. Actuator 1 can use appropriate components as needed, such as oil cylinders, motors, etc. Actuator controller 3 collects the displacement command of the first actuator and the inflow / outflow flow rate. Figure 1 The input end of the flow sensor is connected between valve 2 and actuator 1, thus realizing the acquisition of the inflow flow of actuator 1; when the input end of the flow sensor is connected to the output end of actuator 1, it realizes the acquisition of the outflow flow of actuator 1. Actuator controller 3 outputs the first valve core displacement command. The inflow / outflow flow is related to the actuator displacement. Therefore, the inflow / outflow flow here is actually used as the actuator displacement sample. That is to say, the control objective of actuator controller 3 here is to make the actuator displacement sample follow the first actuator displacement command. Valve controller 4 acquires the first valve core displacement command and valve core displacement sample (acquiring valve core displacement sample through valve core displacement sensor 6), and then outputs valve core control parameters to valve 2. Valve core control parameters include valve core control voltage, current value and other parameters. Actuator 1 generates action displacement under the action of valve 2 pressure control, flow, inertial load and external load.

[0035] The hydraulic valve-controlled actuator displacement control system of this invention achieves actuator displacement control and valve core displacement control through a two-stage controller system consisting of actuator controller 3 and valve controller 4, resulting in high control accuracy. A closed-loop control system is formed by using a flow sensor 5 as feedback for actuator controller 3 and a valve core displacement sensor 6 as feedback for valve controller 4, further enhancing control accuracy. Compared to displacement sensors in traditional technologies, the flow sensor 5 used in this invention indirectly determines the actuator displacement by collecting flow data. The flow sensor 5 is typically housed in a cavity with a certain level of protection, offering strong resistance to contamination and making it more suitable for high-pollution external environments such as anchor drilling rigs. Furthermore, compared to external displacement sensors, it occupies less space, making it suitable for size-constrained environments and providing better compatibility.

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

[0037] Combination Figure 2 As shown, Figure 2 yes Figure 1 Subdivision of actuator controller 3 and valve controller 4 (actuator 1 in Figure 2 (Not shown in the diagram) The actuator displacement sampling is converted into first initialization parameters based on the actuator / load dynamics model. The inflow / outflow rate is converted into actuator displacement sampling according to the actuator model. The first command generator 31 preferably includes a ramp generator and / or a filter. The first command generator 31 can output discrete command signals according to set rules, thereby constraining discrete command signals from input devices such as joysticks and switches to physical limits. In this embodiment, the first actuator displacement command is processed by the first command generator 31 and output as a second actuator displacement command. The actuator displacement controller 32 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 33 considers the proportional valve model (the valve core displacement / flow relationship of the proportional valve) to convert the valve core flow command into a first valve core displacement command (i.e., valve core flow is converted into valve core displacement), thus realizing closed-loop control of the actuator displacement.

[0038] Thus, by constraining the discrete command signal to within physical limits through the first command generator 31, functions such as signal normalization, ramp generation, and constraint protection are achieved, thereby improving the stability of the control system. The actuator displacement controller 32 outputs the valve core flow command based on the actuator displacement sampling, load force, and second actuator displacement command. The flow / displacement conversion module 33 converts the valve core flow command into the first valve core displacement command, thereby realizing closed-loop control of the actuator displacement with high 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 the 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 parameters 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 and protect the output of the actuator displacement controller 32, converting the first valve core displacement command into a second valve core displacement command. Preferably, the second command generator 41 includes a ramp generator and / or a filter. The discrete command signal is output according to set rules, constrained to within physical limits. The valve displacement controller 42 combines the valve core displacement sampling and the second valve core displacement command to output valve core control parameters (i.e., valve core control voltage, current, etc.).

[0041] Thus, the discrete command signal is constrained to the physical limits by the second command generator 41, achieving functions such as signal normalization, ramp generation, and constraint protection, thereby improving the stability of the control system. The valve displacement controller 42 outputs valve core control parameters based on valve core displacement sampling and the second valve core displacement command, thereby realizing closed-loop control of valve core displacement with high 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 command based on the second actuator displacement command, the actuator model, the proportional valve model, and the actuator displacement sampling. The differential filter 323 converts the actuator displacement sampling into speed sampling. The speed controller 322 outputs the valve core flow command based on the speed command and the speed sampling.

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

[0044] In this way, the actuator displacement controller 32 forms a two-level closed-loop cascaded 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), which effectively avoids the overshoot problem that may exist in the displacement controller 321 implemented in a simple PID mode.

[0045] Furthermore, the actuator model includes a hydraulic cylinder model, the expression of which is:

[0046]

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

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

[0049]

[0050] D is the motor displacement, θ p For the motor angle, ω p This refers to the motor speed.

[0051] In this way, based on the motor model and the cylinder model, the displacement / velocity, displacement / flow rate, etc. of the actuator can be transformed.

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

[0053]

[0054] C d Here, is the flow coefficient, w is the gradient of the working chamber area of ​​the valve orifice, and x is... v ρ is the valve core opening, ΔP is the pressure difference between the valve inlet and outlet, and ρ is the fluid density.

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

[0056]

[0057] This refers to the input quantity corresponding to the valve core dead zone, where k is the coefficient of the input quantity minus the proportional valve core displacement, u is the input control quantity, and x is the input control quantity. v This refers to the valve core opening.

[0058] Thus, based on the proportional valve model described above, the valve's displacement / flow rate can be transformed.

[0059] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0060] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A displacement control system for a hydraulic valve-controlled actuator, characterized in that, This includes actuators, valves, actuator controllers, valve controllers, flow sensors, and valve core displacement sensors. 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 command to the valve controller based on the first actuator displacement command and the inflow / outflow of the actuator. The valve core displacement sensor collects valve core displacement samples 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 command and the valve core displacement sampling. The flow sensor collects the inflow / outflow flow and feeds it back 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 command generator, an actuator displacement controller, and a flow / displacement conversion module. The inflow / outflow flow rate is converted into actuator displacement sampling based on the actuator model; The actuator displacement sampling is converted into first initialization parameters based on the 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 parameters; The actuator displacement controller is based on the load force, the second actuator displacement command, and the actuator displacement sampling output valve core flow command; The flow / displacement conversion module converts the valve core flow command into the first valve core displacement command based on the 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 command generator and a valve displacement controller. The proportional valve model is used as the second initialization parameter. The second instruction generator outputs the 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 parameters based on the second valve core displacement command and the valve core displacement sampling.

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 command based on the second actuator displacement command, the actuator model, the proportional valve model, and the actuator displacement sampling. The differential filter converts the actuator displacement sample into a velocity sample; The speed controller outputs the valve core flow command based on the speed command 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 hydraulic cylinder model, and the expression for the hydraulic cylinder model is as follows: A is the area of ​​the hydraulic cylinder, x p For the displacement of the hydraulic cylinder, v p The speed of the hydraulic cylinder.

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 expression for the motor model is: D is the motor displacement, θ p For the motor angle, ω p This represents 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 Here, is the flow coefficient, w is the gradient of the working chamber area of ​​the valve orifice, and x is... v ρ 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: This refers to the input quantity corresponding to the valve core dead zone, where k is the coefficient of the input quantity minus the proportional valve core displacement, u is the input control quantity, and x is the input control quantity. v This refers to 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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