Oil cylinder telescopic stroke obtaining method and system based on inlet and outlet liquid flow
By installing flow sensors on the inlet and outlet pipelines of the hydraulic cylinder, combined with leakage compensation and limit position correction, the accuracy and reliability issues of hydraulic cylinder extension stroke detection in the fully mechanized mining face environment are solved, achieving efficient and economical stroke monitoring.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHENGZHOU HENGDA INTELLIGENT CONTROL TECHNOLOGY CO LTD
- Filing Date
- 2026-02-14
- Publication Date
- 2026-04-21
AI Technical Summary
Existing methods for detecting the extension and retraction stroke of hydraulic cylinders are not accurate enough in the harsh environment of fully mechanized mining faces. External sensors are easily damaged, difficult to install and maintain, have limited measurement range, and the pressure inference method has low accuracy, which cannot meet the needs of intelligent mining.
By employing a method and system based on inlet and outlet fluid flow rates, flow sensors are installed on the inlet and outlet lines of the hydraulic cylinder. Combined with leakage compensation and limit position correction, the extension and retraction stroke of the hydraulic cylinder is calculated, avoiding direct impact from mechanical collisions, vibrations, and dust, thereby reducing maintenance costs.
It improves the accuracy and reliability of hydraulic cylinder extension stroke detection, adapts to the harsh environment of fully mechanized mining faces, reduces maintenance costs, and does not require modification of the cylinder body, making it cheaper than high-precision external displacement sensors.
Smart Images
Figure CN121897640A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of hydraulic cylinder stroke detection, and in particular to a method and system for obtaining the extension and retraction stroke of a hydraulic cylinder based on the inlet and outlet fluid flow rates. Background Technology
[0002] Hydraulic supports are the core equipment of fully mechanized coal mining faces. The extension and retraction stroke of the hydraulic cylinders directly determines the support strength, moving accuracy, and advancing efficiency of the working face. Therefore, accurately obtaining the extension and retraction stroke of the hydraulic cylinders is crucial for realizing automated and intelligent mining in fully mechanized coal mining faces.
[0003] The existing methods for detecting the extension and retraction stroke of hydraulic cylinders involve using external sensors or mechanical detection structures to directly measure the extension and retraction stroke. However, due to the harsh environment of the longwall mining face, which is characterized by high dust, strong vibration, large impact, and hydraulic oil contamination, the accuracy of the detection of the extension and retraction stroke of hydraulic cylinders cannot be guaranteed. Summary of the Invention
[0004] This invention provides a method and system for obtaining the extension and retraction stroke of a hydraulic cylinder based on the inlet and outlet fluid flow rate, which is used to improve the accuracy of detecting the extension and retraction stroke of a hydraulic cylinder in a hydraulic support.
[0005] Specifically, the present invention provides a method for obtaining the extension and retraction stroke of a hydraulic cylinder based on the inlet and outlet fluid flow rates, including: Obtain the working status of the hydraulic cylinder; When the working state is the extension process, the initial extension stroke of the hydraulic cylinder and the fluid flow rate into the rodless chamber are obtained, and the change in volume of the rodless chamber of the hydraulic cylinder is calculated based on the fluid flow rate into the rodless chamber; and The change in the extension stroke of the hydraulic cylinder is calculated based on the change in the volume of the rodless cavity, and the current extension stroke of the hydraulic cylinder is calculated based on the initial extension stroke and the change in the extension stroke. When the operating state is the retraction process, the initial retraction stroke of the hydraulic cylinder and the fluid flow rate in the rod chamber are obtained, and the change in the volume of the rod chamber of the hydraulic cylinder is calculated based on the fluid flow rate in the rod chamber; and The change in the retraction stroke of the hydraulic cylinder is calculated based on the change in the volume of the rod cavity, and the current retraction stroke of the hydraulic cylinder is calculated based on the initial retraction stroke and the change in the retraction stroke.
[0006] Furthermore, before the step of calculating the change in the extension stroke of the hydraulic cylinder based on the change in the volume of the rodless cavity, the method further includes: The return flow rate of the rod chamber of the hydraulic cylinder is obtained, and a preset leakage coefficient is used to compensate for the volume change of the rodless chamber based on the return flow rate of the rod chamber; and Before the step of calculating the change in the retraction stroke of the hydraulic cylinder based on the change in the volume of the rod chamber, the method further includes: The return flow rate of the rodless chamber of the hydraulic cylinder is obtained, and a preset leakage coefficient is used to compensate for the change in volume of the rodless chamber based on the return flow rate.
[0007] Furthermore, after the step of calculating the current extension stroke of the hydraulic cylinder based on the initial extension stroke and the change in extension stroke, the method further includes: Detect whether the hydraulic cylinder has extended to its maximum extension position. If so, correct the current extension stroke to the maximum extension stroke of the hydraulic cylinder. After the step of calculating the current retraction stroke of the hydraulic cylinder based on the initial retraction stroke and the change in retraction stroke, the method further includes: Detect whether the hydraulic cylinder has retracted to its retraction limit position. If so, correct the current retraction stroke to the limit retraction stroke of the hydraulic cylinder.
[0008] In another aspect, the present invention provides a hydraulic cylinder extension stroke acquisition system based on inlet and outlet fluid flow rates, comprising a processor, and an inlet flow sensor and a return flow sensor connected to the processor, for acquiring the inlet flow rate and return flow rate of the hydraulic cylinder, and performing the steps of the hydraulic cylinder extension stroke acquisition method based on inlet and outlet fluid flow rates described above according to the inlet flow rate and the return flow rate.
[0009] Furthermore, the processor is connected to a position sensor, which is used to detect whether the hydraulic cylinder has reached its limit extension stroke or limit retraction stroke.
[0010] Furthermore, the processor is connected to a parameter storage module, which stores the initial extension stroke, the initial retraction stroke, and the rodless chamber parameters and rod chamber parameters of the hydraulic cylinder.
[0011] The technical solution of this invention calculates the current extension / retraction stroke of the hydraulic cylinder based on the hydraulic flow information. Because this invention eliminates the need for an external displacement sensor and employs a flow sensor that can be installed in a relatively well-protected pipeline location, it avoids direct exposure to mechanical impacts, vibrations, and dust, thus adapting to the harsh environment of the longwall mining face and extending its service life. This invention requires no modification to the hydraulic cylinder body; only the flow sensor needs to be installed on the inlet and return pipelines, simplifying the installation process. Furthermore, if the flow sensor fails, it can be quickly replaced without shutting down the system, reducing maintenance costs. Moreover, this invention utilizes the existing hydraulic system pipelines at the working face, eliminating the need for additional complex hardware. The cost of the flow sensor is far lower than that of a high-precision external displacement sensor, resulting in a highly economical overall solution. Therefore, the technical solution of this invention can improve the accuracy and reliability of detecting the extension / retraction stroke of the hydraulic cylinder.
[0012] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description
[0013] The following sections will describe some specific embodiments of the invention in a detailed manner by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings: Figure 1 This is a schematic diagram of a hydraulic cylinder extension stroke acquisition system based on inlet and outlet fluid flow rate according to an embodiment of the present invention; Figure 2 This is a schematic flowchart of a method for obtaining the extension and retraction stroke of a hydraulic cylinder based on the inlet and outlet fluid flow rates according to an embodiment of the present invention. Detailed Implementation
[0014] In the related technologies of this invention, the methods for detecting the extension and retraction stroke of a hydraulic cylinder include direct measurement using a displacement sensor, measurement using a mechanical scale / encoder, and indirect pressure inference. The direct measurement method involves installing an external displacement sensor (such as a magnetostrictive sensor, a wire sensor, or a grating sensor) on the cylinder body or piston rod. This displacement sensor directly collects the extension and retraction distance of the piston rod and transmits it to the control system, thereby achieving stroke monitoring of the hydraulic cylinder. The core of this method is to obtain real-time displacement data of the hydraulic cylinder through the direct linkage between the displacement sensor and the piston rod.
[0015] The mechanical scale / encoder measurement method involves setting a mechanical scale on the outside of the hydraulic cylinder and manually observing and reading the stroke of the hydraulic cylinder; or installing a rotary encoder at the end of the cylinder, using the extension and retraction of the piston rod to drive the encoder gear to rotate, converting linear displacement into a rotational angle signal, and then calculating the stroke of the hydraulic cylinder. This method relies on a mechanical transmission structure to achieve signal conversion.
[0016] The pressure indirect inference method indirectly infers the extension and retraction state of the hydraulic cylinder by monitoring the pressure changes in the inlet and return lines of the hydraulic cylinder and combining the force model of the hydraulic cylinder. However, this method can only determine whether the hydraulic cylinder is in an extended, retracted, or pressure-holding state, and cannot accurately calculate the stroke value.
[0017] The above-mentioned method for detecting the extension and retraction stroke of hydraulic cylinders has the following problems: 1. External sensors are easily damaged: External devices such as displacement sensors and encoders are directly exposed to the harsh environment of the longwall mining face. They are susceptible to dust, hydraulic oil corrosion, mechanical collisions and vibrations, which can cause sensor malfunction, signal drift or damage, resulting in decreased monitoring accuracy or even failure.
[0018] 2. Difficult to install and maintain: External sensors require complex mounting brackets and sealing structures, and the hydraulic cylinder needs to be modified during installation, making construction difficult; if the sensor is damaged, the machine needs to be stopped for replacement, which affects production efficiency and has high maintenance costs.
[0019] 3. Limited measurement range: The measurement range of some sensors (such as wire-type sensors) is limited by their own structure, making them unable to adapt to hydraulic cylinders with different stroke specifications, resulting in poor versatility.
[0020] 4. Low accuracy of pressure inference method: It can only determine the status of the hydraulic cylinder, but cannot provide accurate stroke values, and cannot meet the needs of intelligent mining for high-precision stroke monitoring.
[0021] The following reference Figures 1 to 2 This invention describes a method and system for obtaining the extension and retraction stroke of a hydraulic cylinder based on the inlet and outlet fluid flow rates. In this description, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature, that is, include one or more of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. When a feature "includes or contains" one or more of the features it encompasses, unless otherwise specifically described, this indicates that other features are not excluded and may be further included.
[0022] In the description of this embodiment, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0023] Please see Figure 1 , Figure 1 The diagram shown is a structural schematic of a hydraulic cylinder extension stroke acquisition system based on inlet and outlet fluid flow rate in one embodiment of the present invention. This system can be integrated into the control system of a hydraulic support or into a fully mechanized mining intelligent control platform. It can calculate the extension stroke of the hydraulic cylinder in the hydraulic support based on the inlet fluid flow rate of the hydraulic cylinder, thereby improving the accuracy of acquiring the extension stroke.
[0024] Specifically, the cylinder extension stroke acquisition system based on inlet and outlet fluid flow rate in this embodiment includes a processor 10, which is connected to multiple flow sensors, including a rodless chamber inlet flow sensor 11, a rod chamber inlet flow sensor 12, a rodless chamber return flow sensor 13, and a rod chamber return flow sensor 14. These flow sensors can be electromagnetic flow sensors or turbine flow sensors.
[0025] In this embodiment, the rodless cavity inlet flow sensor 11 is mounted on the inlet pipe of the rodless cavity of the hydraulic cylinder to detect the inlet flow rate of the rodless cavity; the rod cavity inlet flow sensor 12 is mounted on the inlet pipe of the rod cavity of the hydraulic cylinder to detect the inlet flow rate of the rod cavity; the rodless cavity return flow sensor 13 is mounted on the return pipe of the rodless cavity to detect the return flow rate of the rodless cavity; and the rod cavity return flow sensor 14 is mounted on the return pipe of the rod cavity of the hydraulic cylinder to detect the return flow rate of the rod cavity.
[0026] In this embodiment, the processor 10 acquires the flow information detected by the flow sensor and executes a method for acquiring the extension and retraction stroke of the hydraulic cylinder based on the inlet and outlet fluid flow to obtain the extension and retraction stroke of the hydraulic cylinder.
[0027] The method for obtaining the cylinder extension / retraction stroke based on the inlet and outlet fluid flow rates in this embodiment is as follows: Figure 2 As shown, the specific steps include the following: Step S101: Obtain the working status of the hydraulic cylinder; If the hydraulic cylinder is in the extension process, then step S111 is executed; if the hydraulic cylinder is in the retraction process, then step S121 is executed. Step S111: Obtain the initial extension stroke of the hydraulic cylinder and the fluid flow rate in the rodless chamber, and calculate the volume change of the rodless chamber of the hydraulic cylinder based on the fluid flow rate in the rod chamber. Step S112: Calculate the change in the extension stroke of the hydraulic cylinder based on the change in the volume of the rodless chamber of the hydraulic cylinder, and calculate the current extension stroke of the hydraulic cylinder based on the change in the extension stroke and the initial extension stroke of the hydraulic cylinder. Step S121: Obtain the initial retraction stroke of the hydraulic cylinder and the fluid flow rate in the rod chamber, and calculate the change in the volume of the rod chamber of the hydraulic cylinder based on the fluid flow rate in the rod chamber. Step S122: Calculate the change in the retraction stroke of the hydraulic cylinder based on the change in the volume of the rod chamber of the hydraulic cylinder, and calculate the current retraction stroke of the hydraulic cylinder based on the change in the retraction stroke and the initial retraction stroke of the hydraulic cylinder.
[0028] In step S101 above, the pressure indirect inference method can be used to infer whether the hydraulic cylinder is in the extension or retraction process by monitoring the pressure changes in the inlet and return lines of the hydraulic cylinder.
[0029] In this embodiment, if the hydraulic cylinder is in the extension process, fluid enters the rodless chamber and returns to the rod chamber; if the hydraulic cylinder is in the retraction process, fluid enters the rod chamber and returns to the rodless chamber. Therefore, the extension or retraction process of the hydraulic cylinder can be determined based on the fluid entry and return states of the rodless and rod chambers.
[0030] In step S111 above, the initial extension stroke of the hydraulic cylinder refers to the stroke when the hydraulic cylinder begins to perform the extension action. The extension stroke can be recorded after the hydraulic cylinder finishes its work, and this extension stroke can be used as the initial extension stroke for the next extension operation.
[0031] In this embodiment, the fluid flow rate of the rod chamber of the hydraulic cylinder can be periodically obtained, assuming that at any given time... The fluid flow rate detected in the rod chamber of the hydraulic cylinder is: That is, the inlet flow rate of the rod chamber of the hydraulic cylinder is And the current time is the nth detection time. The change in volume of the rodless chamber of the hydraulic cylinder from the initial retraction to the current moment is: That is, the volume change of the rod chamber of the hydraulic cylinder from the start of its extension to the current moment is... ,but
[0032] In step S112 above, it is assumed that the effective working area of the rodless chamber of the hydraulic cylinder is... The change in the extension stroke of the hydraulic cylinder at the current moment is ,but
[0033] Let the initial extension stroke of the hydraulic cylinder be... And the current extension stroke of the hydraulic cylinder is L, then
[0034] In step S121 above, the initial retraction stroke of the hydraulic cylinder refers to the stroke when the hydraulic cylinder begins to perform the retraction action. The extension and retraction stroke can be recorded after the hydraulic cylinder finishes its work, and this extension and retraction stroke can be used as the initial retraction stroke for the next retraction operation.
[0035] In this embodiment, the fluid flow rate of the rod chamber of the hydraulic cylinder can be periodically obtained, assuming that at any given time... The fluid flow rate detected in the rod chamber of the hydraulic cylinder is: That is, the inlet flow rate of the rod chamber of the hydraulic cylinder is And the current time is the nth detection time. The change in volume of the rodless chamber of the hydraulic cylinder from the initial retraction to the current moment is: That is, the volume change of the rod chamber of the hydraulic cylinder from the start of its extension to the current moment is... ,but
[0036] In step S122 above, it is assumed that the effective working area of the rod chamber of the hydraulic cylinder is... The change in the retraction stroke of the hydraulic cylinder at the current moment is: ,but
[0037] Let the initial extension stroke of the hydraulic cylinder be... And the current extension stroke of the hydraulic cylinder is ,but
[0038] As described above, this embodiment calculates the current extension / retraction stroke of the hydraulic cylinder using the hydraulic flow information. Because this embodiment eliminates the need for an external displacement sensor and employs a flow sensor that can be installed in a relatively well-protected pipeline location, it avoids direct exposure to mechanical impacts, vibrations, and dust, thus adapting to the harsh environment of the longwall mining face and extending its service life. This embodiment requires no modification to the hydraulic cylinder body; only the flow sensors need to be installed on the inlet and return pipelines, simplifying the installation process. Furthermore, if the flow sensor fails, it can be quickly replaced without shutting down the machine, reducing maintenance costs. Moreover, this embodiment utilizes the existing hydraulic system pipelines at the working face, eliminating the need for additional complex hardware. The cost of the flow sensor is far lower than that of a high-precision external displacement sensor, resulting in a more economical overall solution. Therefore, this embodiment can improve the accuracy and reliability of detecting the extension / retraction stroke of the hydraulic cylinder.
[0039] In some embodiments of the present invention, before calculating the change in the extension stroke of the hydraulic cylinder based on the change in the volume of the rodless chamber of the hydraulic cylinder in step S112, the method further includes: obtaining the return flow rate of the rod chamber of the hydraulic cylinder, and using a preset leakage coefficient to compensate for the change in the volume of the rodless chamber of the hydraulic cylinder based on the return flow rate of the rod chamber.
[0040] In this embodiment, it is assumed that the return flow rate of the rod chamber of the hydraulic cylinder is... The preset leakage coefficient is k, and the volume change of the rodless chamber of the compensated hydraulic cylinder is... ,but
[0041] After obtaining the compensated change in the volume of the rodless chamber of the hydraulic cylinder in step S112 above, the change in the extension stroke of the hydraulic cylinder is calculated based on the compensated change in the volume of the rodless chamber, and the current extension stroke of the hydraulic cylinder is obtained based on the change in the extension stroke and the initial extension stroke of the hydraulic cylinder.
[0042] Accordingly, before calculating the change in the retraction stroke of the hydraulic cylinder based on the change in the volume of the rod chamber of the hydraulic cylinder in step S122, the method further includes: obtaining the return flow rate of the rodless chamber of the hydraulic cylinder, and using a preset leakage coefficient to compensate for the change in the volume of the rod chamber of the hydraulic cylinder based on the return flow rate of the rodless chamber.
[0043] In this embodiment, it is assumed that the return flow rate of the rodless chamber of the hydraulic cylinder is... The preset leakage coefficient is k, and the volume change of the rod chamber of the compensated hydraulic cylinder is... ,but
[0044] After obtaining the compensated change in the volume of the rod chamber of the hydraulic cylinder in step S122 above, the change in the retraction stroke of the hydraulic cylinder is calculated based on the compensated change in the volume of the rod chamber, and the current retraction stroke of the hydraulic cylinder is obtained based on the change in the retraction stroke and the initial retraction stroke of the hydraulic cylinder.
[0045] In this embodiment, before calculating the current extension stroke or the current retraction stroke of the hydraulic cylinder, the leakage volume of the hydraulic oil is subtracted from the change in the volume of the rodless chamber or the change in the volume of the rod chamber. This is done by using a leakage coefficient to compensate for the change in the volume of the rodless chamber or the change in the volume of the rod chamber, thereby improving the accuracy of detecting the extension and retraction stroke of the hydraulic cylinder.
[0046] In some embodiments of the present invention, after calculating the current extension stroke of the hydraulic cylinder in step S112, the method further includes: Check whether the hydraulic cylinder has extended to its maximum extension position; If so, the current extension stroke of the hydraulic cylinder will be corrected to the maximum extension stroke of the hydraulic cylinder.
[0047] Accordingly, before calculating the current retraction stroke of the hydraulic cylinder in step S122, the following steps are also included: Check whether the hydraulic cylinder has retracted to its maximum retraction position; If so, the current retraction stroke of the hydraulic cylinder will be corrected to the limit retraction stroke of the hydraulic cylinder.
[0048] This embodiment effectively reduces the calculation error of the current extension / retraction stroke of the hydraulic cylinder by distinguishing the effective working area of the extension / retraction process and introducing leakage compensation and limit position correction mechanisms, thus ensuring the accuracy of monitoring the extension stroke of the hydraulic cylinder.
[0049] In some embodiments of the present invention, the processor 10 is also connected to a position sensor, which includes an extension limit position sensor 21 and a retraction limit position sensor 22. Both the extension limit position sensor 21 and the retraction limit position sensor 22 are limit switches. The extension limit position sensor 21 is mounted at the extension limit position of the hydraulic cylinder and is used to detect whether the hydraulic cylinder has extended to its extension limit position. The retraction limit position sensor 22 is mounted at the retraction limit position of the hydraulic cylinder and is used to detect whether the hydraulic cylinder has retracted to its retraction limit position.
[0050] In some embodiments of the present invention, the processor 10 is also connected to a parameter storage module 20, which stores the initial extension stroke and initial retraction stroke of the hydraulic cylinder, as well as the rodless chamber parameters and rod chamber parameters of the hydraulic cylinder.
[0051] After obtaining the compensated change in the volume of the rod chamber of the hydraulic cylinder in step S122 above, the change in the retraction stroke of the hydraulic cylinder is calculated based on the compensated change in the volume of the rod chamber, and the current retraction stroke of the hydraulic cylinder is obtained based on the change in the retraction stroke and the initial retraction stroke of the hydraulic cylinder.
[0052] In this embodiment, before calculating the current extension stroke or the current retraction stroke of the hydraulic cylinder, the leakage volume of the hydraulic oil is subtracted from the change in the volume of the rodless chamber or the change in the volume of the rod chamber. This is done by using a leakage coefficient to compensate for the change in the volume of the rodless chamber or the change in the volume of the rod chamber, thereby improving the accuracy of detecting the extension and retraction stroke of the hydraulic cylinder.
[0053] In some embodiments of the present invention, after calculating the current extension stroke of the hydraulic cylinder in step S112, the method further includes: Check whether the hydraulic cylinder has extended to its maximum extension position; If so, the current extension stroke of the hydraulic cylinder will be corrected to the maximum extension stroke of the hydraulic cylinder.
[0054] Accordingly, before calculating the current retraction stroke of the hydraulic cylinder in step S122, the following steps are also included: Check whether the hydraulic cylinder has retracted to its maximum retraction position; If so, the current retraction stroke of the hydraulic cylinder will be corrected to the limit retraction stroke of the hydraulic cylinder.
[0055] This embodiment effectively reduces the calculation error of the current extension / retraction stroke of the hydraulic cylinder by distinguishing the effective working area of the extension / retraction process and introducing leakage compensation and limit position correction mechanisms, thus ensuring the accuracy of monitoring the extension stroke of the hydraulic cylinder.
[0056] In some embodiments of the present invention, the processor 10 is also connected to a position sensor, which includes an extension limit position sensor 21 and a retraction limit position sensor 22. Both the extension limit position sensor 21 and the retraction limit position sensor 22 are limit switches. The extension limit position sensor 21 is mounted at the extension limit position of the hydraulic cylinder and is used to detect whether the hydraulic cylinder has extended to its extension limit position. The retraction limit position sensor 22 is mounted at the retraction limit position of the hydraulic cylinder and is used to detect whether the hydraulic cylinder has retracted to its retraction limit position.
[0057] In some embodiments of the present invention, the processor 10 is also connected to a parameter storage module 20, which stores the initial extension stroke and initial retraction stroke of the hydraulic cylinder, as well as the rodless chamber parameters and rod chamber parameters of the hydraulic cylinder.
[0058] In this embodiment, the parameter storage module 20 is a hardware storage device with data storage function. The rodless chamber parameters of the hydraulic cylinder include the effective working area of the rodless chamber. The rod cavity parameters include the effective working area of the rod cavity. .
[0059] After the hydraulic cylinder stops working, the current extension stroke or the current retraction stroke of the hydraulic cylinder is taken as the current extension stroke of the hydraulic cylinder, and the current extension stroke is stored in the parameter storage module 20 as the initial extension stroke for the next extension operation or the initial retraction stroke for the next retraction operation.
[0060] In this embodiment, only the non-sensory strength parameters and rod chamber parameters of the hydraulic cylinder stored in the parameter storage module 20 need to be modified to realize the stroke monitoring of different hydraulic cylinders. No special equipment needs to be customized. Therefore, the applicability of the system of the present invention can be improved, making it applicable to various types and specifications of hydraulic cylinders.
[0061] The flowcharts provided in this embodiment are not intended to indicate that the operations of the method will be performed in any particular order, or that all operations of the method are included in every case. Furthermore, the method described above may include additional operations. Within the scope of the technical concept provided by the method in this embodiment, additional variations can be made to the method described above.
[0062] It should be understood that in some embodiments, the components may be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods may be implemented using software or firmware stored in memory and executed by a suitable instruction execution system.
[0063] Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.
Claims
1. A method for obtaining the extension and retraction stroke of a hydraulic cylinder based on inlet and outlet fluid flow rates, characterized in that, include: Obtain the working status of the hydraulic cylinder; When the working state is the extension process, the initial extension stroke of the hydraulic cylinder and the fluid flow rate of the rodless chamber are obtained, and the change in volume of the rodless chamber of the hydraulic cylinder is calculated based on the fluid flow rate of the rodless chamber. as well as The change in the extension stroke of the hydraulic cylinder is calculated based on the change in the volume of the rodless cavity, and the current extension stroke of the hydraulic cylinder is calculated based on the initial extension stroke and the change in the extension stroke. When the working state is the retraction process, the initial retraction stroke of the hydraulic cylinder and the fluid flow rate in the rod chamber are obtained, and the change in the volume of the rod chamber of the hydraulic cylinder is calculated based on the fluid flow rate in the rod chamber. as well as The change in the retraction stroke of the hydraulic cylinder is calculated based on the change in the volume of the rod chamber, and the current retraction stroke of the hydraulic cylinder is calculated based on the initial retraction stroke and the change in the retraction stroke.
2. The method for obtaining the cylinder extension / retraction stroke based on inlet / outlet fluid flow rate according to claim 1, characterized in that, Before the step of calculating the change in the extension stroke of the hydraulic cylinder based on the change in the volume of the rodless cavity, the method further includes: The return flow rate of the rod chamber of the hydraulic cylinder is obtained, and a preset leakage coefficient is used to compensate for the volume change of the rodless chamber based on the return flow rate of the rod chamber; and Before the step of calculating the change in the retraction stroke of the hydraulic cylinder based on the change in the volume of the rod chamber, the method further includes: The return flow rate of the rodless chamber of the hydraulic cylinder is obtained, and a preset leakage coefficient is used to compensate for the change in volume of the rodless chamber based on the return flow rate.
3. The method for obtaining the cylinder extension / retraction stroke based on inlet / outlet fluid flow rate according to claim 1, characterized in that, After the step of calculating the current extension stroke of the hydraulic cylinder based on the initial extension stroke and the change in extension stroke, the method further includes: Detect whether the hydraulic cylinder has extended to its maximum extension position; if so, correct the current extension stroke to the maximum extension stroke of the hydraulic cylinder; and After the step of calculating the current retraction stroke of the hydraulic cylinder based on the initial retraction stroke and the change in retraction stroke, the method further includes: Detect whether the hydraulic cylinder has retracted to its retraction limit position. If so, correct the current retraction stroke to the limit retraction stroke of the hydraulic cylinder.
4. A system for obtaining the extension and retraction stroke of a hydraulic cylinder based on inlet and outlet fluid flow rates, characterized in that, It includes a processor, and an inlet flow sensor and a return flow sensor connected to the processor, to obtain the inlet flow rate of the rod chamber, the inlet flow rate of the rodless chamber, the return flow rate of the rod chamber, and the return flow rate of the rodless chamber of the hydraulic cylinder, and to perform the steps of the cylinder extension stroke acquisition method based on the inlet and outlet flow rates as described in any one of claims 1-3.
5. The hydraulic cylinder extension / retraction stroke acquisition system based on inlet / outlet fluid flow rate according to claim 4, characterized in that, The processor is connected to a position sensor, which is used to detect whether the hydraulic cylinder has reached its limit extension stroke or limit retraction stroke.
6. The hydraulic cylinder extension / retraction stroke acquisition system based on inlet / outlet fluid flow rate according to claim 4, characterized in that, The processor is connected to a parameter storage module, which stores the initial extension stroke, the initial retraction stroke, and the rodless chamber parameters and rod chamber parameters of the hydraulic cylinder.