Compact coal mining machine rocker arm angle measuring device based on liquid level sensing

Abstract

The invention belongs to the technical field of angle measurement, and discloses a compact coal mining machine rocker arm angle measuring device based on liquid level sensing, which comprises a closed pipe, a capacitive sensor, a signal processing unit and a main control system, the closed pipe is fixed on a vertical panel of a rocker arm of the coal mining machine, capacitive sensors are symmetrically arranged on the outer side wall of the closed pipe, the capacitive sensors are electrically connected with the signal processing unit, and the signal processing unit is in communication connection with the main control system. According to the technical scheme, stable and reliable monitoring is achieved in swing angle detection of the rocker arm of the coal mining machine, and the actual requirements under the underground operation environment are met.

Description

Technical Field

[0001] This invention belongs to the field of angle measurement technology, and in particular relates to a compact coal mining machine rocker arm angle measuring device based on liquid level sensing. Background Technology

[0002] Currently, the detection of the rocker arm swing angle of coal mining machines mainly relies on traditional equipment such as accelerometers, gyroscopes, and laser encoders. However, these traditional detection methods have revealed many technical shortcomings in practical applications: First, the accuracy is difficult to meet the requirements. Accelerometers are easily affected by vibration in the complex and harsh underground working environment, causing their measurement accuracy to fall short of the critical ±0.5° target. Second, the structure is complex and the installation conditions are demanding. The encoder must be rigidly connected to the rocker arm rotation shaft during installation, which places extremely high demands on the mechanical assembly environment and increases the difficulty and cost of installation. Third, the maintenance costs are high. Gyroscope circuit modules frequently fail and require frequent calibration to maintain their performance, further increasing the operating costs. In summary, the existing technology has many shortcomings and cannot achieve stable and reliable monitoring in the detection of the rocker arm swing angle of coal mining machines, thus failing to meet the actual needs of complex underground working environments. Summary of the Invention

[0003] The purpose of this invention is to provide a compact coal mining machine rocker arm angle measuring device based on liquid level sensing, so as to solve the problems existing in the prior art.

[0004] To achieve the above objectives, the present invention provides a compact coal mining machine rocker arm angle measuring device based on liquid level sensing, comprising a closed tube, a capacitive sensor, a signal processing unit, and a main control system; the closed tube is fixed on the vertical panel of the coal mining machine rocker arm, and capacitive sensors are symmetrically installed on the outer side wall of the closed tube, the capacitive sensors are electrically connected to the signal processing unit, and the signal processing unit is communicatively connected to the main control system.

[0005] Optionally, the sealed tube contains a liquid medium and an air medium distributed in a preset volume ratio.

[0006] Optionally, the volume ratio of the liquid medium to the air medium is 1:1.

[0007] Optionally, the liquid medium is a high-concentration aqueous solution of cesium salt or rubidium salt.

[0008] Optionally, the middle part of the capacitive sensor is located on the outer wall corresponding to the initial position of the liquid-gas interface inside the closed tube.

[0009] Optionally, the sealing tube may be an annular sealing tube or a U-shaped sealing tube.

[0010] Optionally, the signal processing unit includes a conditioning circuit, an A / D conversion module, and a microcontroller connected in sequence. The conditioning circuit is connected to the capacitive sensor, and the microcontroller is communicatively connected to the main control system.

[0011] Optionally, the microcontroller calculates the liquid level offset Δh using the difference method or a calibration model, and derives the swing angle θ based on the liquid level offset;

[0012] The specific formula for calculating the swing angle θ is as follows:

[0013]

[0014] In the formula, L is the radius of the closed pipe or the spacing between the branches.

[0015] The technical effects of this invention are as follows:

[0016] This invention features a simple structure and low cost, eliminating the need for mechanical transmission components and relying solely on capillary action to maintain liquid seal stability. Furthermore, it utilizes a cesium / rubidium salt solution; the dielectric constant of this solution allows minute displacements on the order of 0.1 mm to be converted into significant electrical signal changes, achieving high-precision detection. Simultaneously, this invention exhibits strong vibration resistance; by employing fluid inertia for physical filtering, it maintains a high signal-to-noise ratio even in environments with severe coal mining machine vibrations. In summary, this invention provides stable and reliable monitoring for the rocker arm angle detection of coal mining machines, meeting the practical needs of complex underground mining operations. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0019] Figure 1 This is a schematic diagram of the angle measuring device when using an annular closed tube in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the angle measuring device when a U-shaped closed tube is used in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the installation position of the angle measuring device on the rocker arm of the coal mining machine when using an annular closed tube in an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram showing the installation position of the angle measuring device on the rocker arm of the coal mining machine when using a U-shaped closed tube in an embodiment of the present invention.

[0023] Labeling explanations: 1. Annular closed tube; 2. U-shaped closed tube; 3. Capacitive sensor; 4. Coal mining machine rocker arm. Detailed Implementation

[0024] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0025] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0026] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0027] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] like Figure 1 - Figure 4 As shown, this embodiment provides a compact coal mining machine rocker arm angle measuring device based on liquid level sensing, including a closed tube, a capacitive sensor 3, a signal processing unit, and a main control system; the closed tube is fixed on the vertical panel of the coal mining machine rocker arm 4, and the capacitive sensor 3 is symmetrically installed on the outer wall of the closed tube. The capacitive sensor 3 is electrically connected to the signal processing unit, and the signal processing unit is communicatively connected to the main control system.

[0030] This embodiment features a simple structure and low cost, with no mechanical transmission components, relying solely on capillary action to maintain liquid seal stability. It also utilizes a cesium / rubidium salt solution; the dielectric constant of the cesium / rubidium salt solution allows minute displacements on the order of 0.1 mm to be converted into significant electrical signal changes, achieving high-precision detection. Furthermore, this embodiment exhibits strong vibration resistance; by utilizing fluid inertia for physical filtering, it maintains a high signal-to-noise ratio even in environments with severe coal mining machine vibrations.

[0031] This embodiment provides a coal mining machine rocker arm swing angle detection device based on liquid level changes, specifically including the following components:

[0032] The sealed tube, using either a ring-shaped sealed tube 1 or a U-shaped sealed tube 2, is made of glass, polyethylene (PE), or polypropylene (PP), with an inner diameter ≥6mm. The wall thickness is selected based on the material. The overall height of the sealed tube is 50–80mm (if designed as a U-shape, the distance between the two branches must meet this range). The sealed tube must be designed to ensure a stable liquid-gas interface when installed vertically. The liquid occupies half of the tube's volume, with the other half being air. The liquid is a high-concentration cesium or rubidium salt aqueous solution, with a concentration range of 50%–80%, to achieve a sufficiently high dielectric constant (>40) and high density (≥1.5g / cm³). 3 ).

[0033] A symmetrical capacitive sensor 3 is installed on the wall of the closed tube. The capacitive sensor 3 is a long strip sensor that is attached to both sides of the outer side of the tube wall. Its length covers a semicircle or half of the U-shaped tube arc surface. The center of the sensor is precisely located at the initial position of the liquid-gas interface, so as to realize sensitive detection of liquid level changes.

[0034] Signal processing unit: Includes conditioning circuitry, an A / D conversion module, and a microcontroller. It converts capacitive signals into angle data and supports digital or wireless transmission to the main control system. The sensor converts the acquired signals into electrical signals. Since the electrical signals output by the sensor may be weak or contain noise, they need to be amplified, filtered, and linearized by the conditioning circuitry. The A / D conversion module is responsible for converting the analog signals output by the conditioning circuitry into digital signals for processing by the microcontroller.

[0035] The sealed tube is equipped with an outer shell cover. The outer shell cover is made of metal or engineering plastic and has a flat structure (thickness 1-2cm, length and width ≤10×5cm). It has a straight bottom edge to facilitate precise positioning when installed perpendicular to the plane of the coal mining machine rocker arm 4.

[0036] The working principle of this embodiment is as follows:

[0037] Device installation: Fix the swing angle detection device to the vertical panel of the rocker arm 4 of the coal mining machine (initially in a horizontal position).

[0038] Swing angle change triggers liquid level movement: When the rocker arm 4 of the coal mining machine rotates, causing the equipment to tilt, the liquid is displaced vertically by gravity.

[0039] Capacitance detection and calculation: The liquid-gas interface forms a dynamic boundary as the angle changes, and the capacitance sensors 3 on both sides measure the high dielectric constant (liquid side) and the low dielectric constant (air side) respectively.

[0040] The microcontroller calculates the liquid level offset Δh using the difference method or a calibration model, and then derives the swing angle θ, as shown in the following formula:

[0041]

[0042] In the formula, L is the characteristic length of the pipe (radius or branch spacing).

[0043] Furthermore, this embodiment significantly improves the temperature stability and measurement accuracy of liquid expansion sensors or related measurement systems by pre-calibrating the liquid expansion coefficient at different temperatures and using software algorithms to correct for temperature drift, effectively solving the measurement error problem caused by temperature changes.

[0044] In summary, this embodiment achieves stable and reliable monitoring in the rocker arm swing angle detection of the coal mining machine, meeting the actual needs in the underground working environment.

[0045] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A compact coal mining machine rocker arm angle measuring device based on liquid level sensing, characterized in that, It includes a closed tube, a capacitive sensor (3), a signal processing unit, and a main control system; the closed tube is fixed on the vertical panel of the rocker arm (4) of the coal mining machine, and the capacitive sensor (3) is symmetrically installed on the outer wall of the closed tube. The capacitive sensor (3) is electrically connected to the signal processing unit, and the signal processing unit is communicatively connected to the main control system.

2. The apparatus according to claim 1, characterized in that, The sealed tube contains a liquid medium and an air medium distributed in a preset volume ratio.

3. The apparatus according to claim 2, characterized in that, The volume ratio of the liquid medium to the air medium is 1:

1.

4. The apparatus according to claim 2, characterized in that, The liquid medium is a high-concentration aqueous solution of cesium or rubidium salt.

5. The apparatus according to claim 2, characterized in that, The middle part of the capacitive sensor (3) is located on the outer wall corresponding to the initial position of the liquid-gas interface inside the closed tube.

6. The apparatus according to claim 1, characterized in that, The sealing tube is either a ring-shaped sealing tube (1) or a U-shaped sealing tube (2).

7. The apparatus according to claim 1, characterized in that, The signal processing unit includes a conditioning circuit, an A / D conversion module and a microcontroller connected in sequence. The conditioning circuit is connected to the capacitive sensor (3), and the microcontroller is communicatively connected to the main control system.

8. The apparatus according to claim 7, characterized in that, The microcontroller calculates the liquid level offset Δh using the difference method or calibration model, and derives the swing angle θ based on the liquid level offset; The specific formula for calculating the swing angle θ is as follows: In the formula, L is the radius of the closed pipe or the spacing between the branches.

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