An intelligent solution method for the support posture of a two-column shield hydraulic support

Abstract

The present invention discloses an intelligent solution method for the support posture of a two-column shielding hydraulic support, which takes the stroke of the column jack and the balance jack of the hydraulic support as independent variables, and intelligently solves the support posture of the hydraulic support in different support states (when the column jack and the balance jack take different stroke values) according to the structural parameters of the hydraulic support. First, according to the main structural form of the hydraulic support, the structural parameters of the main frame of the hydraulic support are extracted, and the size of the main frame of the hydraulic support is measured; the stroke of the column jack and the stroke of the balance jack are monitored; according to the distance relationship between the marking points of the main frame of the hydraulic support, a set of equations for solving the coordinate values ​​of the marking points of the main frame of the hydraulic support is constructed; the coordinate values ​​of the marking points of the main frame of the hydraulic support are solved; according to the coordinate values ​​of the marking points of the main frame structure of the hydraulic support, the angles between the top beam, the shielding beam, the front connecting rod, the rear connecting rod and the lower surface of the base of the hydraulic support are solved respectively; according to the solved angle values ​​between the top beam, the shielding beam, the front connecting rod, the rear connecting rod and the lower surface of the base of the hydraulic support, the support posture of the hydraulic support is determined.

Description

Technical Field

[0001] The present invention relates to the field of intelligent mining of coal mining working faces, and in particular to a method for intelligently calculating the support posture and support height of a two-column shielding hydraulic support of a coal mining working face, which can intelligently calculate the support posture and support height of the hydraulic support according to the telescopic stroke of the columns of the hydraulic support and the telescopic stroke of the balancing jack. Background Art

[0002] The coal mining face in a coal mine mainly adopts two mining methods: one-time mining of full height and comprehensive mining with top coal caving. Among them, the one-time mining of full height face mainly adopts two-column shielding hydraulic support to support the roof of the working face. The support posture and support height of the hydraulic support directly affect the surrounding rock control effect and intelligence level of the working face, and are two very important parameters for the comprehensive mining face.

[0003] At present, inclination sensors are mainly used at home and abroad to monitor the support posture of hydraulic supports. It is necessary to install an inclination sensor on the top beam, base, cover beam or four-link of the hydraulic support respectively. However, the inclination sensor is affected by the complex and harsh production environment underground in coal mines, and the monitoring data is very easy to be distorted. In addition, there are many difficulties in data fusion processing and rapid solution of multiple inclination sensors, which makes it difficult to meet the needs of intelligent mining on the working face.

[0004] In order to solve the above-mentioned problems of traditional inclination sensors, some scholars have proposed a hydraulic support support posture monitoring method based on machine vision. For example, the invention patent with application number 201710040395.1 discloses a system and method for measuring the support height and posture of the top beam of a hydraulic support. By installing visual modules on the top beam and base of the hydraulic support respectively, the support height and top beam inclination of the hydraulic support are solved based on image processing technology; the invention patent with application number 202010741993.3 discloses a device for measuring the support height and top beam inclination of a hydraulic support in a comprehensive mining working face, and the posture of the hydraulic support is perceived by an infrared dot matrix projector and a visual measurement device; the invention patent with application number 202010183119.2 discloses a method for determining the working state of a two-column hydraulic support. By installing inclination sensors at different positions of the hydraulic support, the support posture and height of the hydraulic support are solved through the relationship between different inclination sensors.

[0005] From the above analysis, it can be seen that traditional inclination sensors are prone to data distortion and difficulty in multi-sensor data fusion, making it difficult to perceive the support posture of the hydraulic support; visual sensors have problems such as low sensitivity underground, difficulty in determining the marking points, and a large impact of the viewing angle on the results, which makes it difficult to effectively and quickly solve the support posture and height of the hydraulic support. Summary of the invention

[0006] In view of the above problems, the present invention proposes an intelligent solution method for the support posture of a two-column shielding hydraulic support, which mainly includes:

[0007] S001, extracting structural parameters of the main frame of the hydraulic support according to the main structural form of the hydraulic support, and measuring and obtaining the dimensions of the main frame of the hydraulic support;

[0008] S002, monitoring and obtaining the stroke of the column jack and the stroke of the balance jack;

[0009] S003, establishing a plane rectangular coordinate system, and constructing an equation group for solving the coordinate values ​​of each identification point of the main frame of the hydraulic support according to the distance relationship between each identification point of the main frame of the hydraulic support;

[0010] S004, solving the coordinate values ​​of each identification point of the main frame of the hydraulic support;

[0011] S005, according to the coordinate values ​​of each identification point of the main frame structure of the hydraulic support, respectively solve the angles between the top beam, the shield beam, the front connecting rod, the rear connecting rod of the hydraulic support and the lower surface of the base;

[0012] S006, determining the support posture of the hydraulic support according to the calculated angle values ​​between the hydraulic support top beam, the shield beam, the front connecting rod, the rear connecting rod and the lower surface of the base.

[0013] Further, the structural parameters of the main frame of the hydraulic support are obtained by measuring the distance between the marking points on the main frame of the hydraulic support. The hinge point between the column jack and the top beam is point A, the hinge point between the column jack and the base is point G, the hinge point between the balance jack and the top beam is point B, the hinge point between the balance jack and the shielding beam is point D, the hinge point between the top beam and the shielding beam is point C, the hinge point between the shielding beam and the front connecting rod is point E, the hinge point between the shielding beam and the rear connecting rod is point F, the hinge point between the front connecting rod and the base is point H, and the hinge point between the rear connecting rod and the base is point I;

[0014] In addition, K, L, and M are fixed connection points, which respectively represent the vertical projection points from the hinge points of the column jack, the balance jack, the shielding beam and the top beam to the upper surface of the top beam; N, O, and P are fixed connection points, which respectively represent the vertical projection points from the hinge points of the balance jack, the front connecting rod, the rear connecting rod and the shielding beam to the upper surface of the shielding beam; R, S, and T are fixed connection points, which respectively represent the vertical projection points from the hinge points of the column jack, the front connecting rod, the rear connecting rod and the base to the lower surface of the base; Point J represents the front end point of the upper surface of the top beam, and Points Q and U represent the two end points of the lower surface of the base.

[0015] For the convenience of expression, the length between each marking point is to To express.

[0016] Furthermore, the stroke of the column jack , Balance jack travel , by installing travel sensors inside the column jack and balance jack, or by using machine vision and laser ranging methods to monitor and obtain.

[0017] Furthermore, the construction of the equation group for solving the coordinate values ​​of each identification point of the main frame of the hydraulic support mainly includes:

[0018] T01, according to the coordinates of the top beam, column jack, balance jack, shield beam, front link, rear link, and hinge points (A, B, C, D, E, F, G, H, I) of the hydraulic support, establish the equilibrium equation group:

[0019] ;

[0020] Substituting the stroke of the monitored column jack and the stroke of the balance jack into the above formula, the coordinate values ​​of points A, B, C, D, E, and F can be determined;

[0021] T02, based on the coordinate values ​​of points A and B, and the distance relationship between the marking points on the top beam, construct a set of equations to solve the coordinates of points J, K, M, and L:

[0022] ;

[0023] T03, based on the coordinate values ​​of points D, E, and F, and the distance relationship between the marking points on the shield beam, construct a set of equations to solve the coordinates of points N, O, and P:

[0024] .

[0025] Furthermore, the coordinate values ​​of each identification point of the main frame of the hydraulic support are solved mainly by Newton iteration method, chord cut method and Broyden method.

[0026] Furthermore, the angles between the top beam, the shield beam, the front connecting rod, the rear connecting rod and the lower surface of the base of the hydraulic support are calculated respectively, including:

[0027] According to the coordinate values ​​of points K and L, the angle between the top beam and the base is calculated as follows: :

[0028] ;

[0029] when When it is positive, that is, the ordinate of point L is greater than that of point K, it means that the top beam of the hydraulic support is "lowering"; when When it is a negative value, that is, the ordinate of point L is less than that of point K, it means that the top beam of the hydraulic support is "warped up";

[0030] According to the coordinate values ​​of points C and P, the angle between the shield beam and the base is calculated, and the angle between the shield beam and the base (negative direction of the x-axis) is :

[0031] ;

[0032] According to the coordinate values ​​of points E and H, the angle between the front link and the base is calculated, and the angle between the front link and the base (positive direction of the x-axis) is :

[0033] ;

[0034] According to the coordinate values ​​of points F and I, the angle between the rear link and the base can be calculated as follows: :

[0035] . BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A flow chart of an intelligent solution method for the support posture of a two-column shielding hydraulic support proposed by the present invention;

[0037] Figure 2 This is a schematic diagram of the connection of the main frame of the hydraulic support;

[0038] Figure 3 It is the main frame structural parameters and identification point location diagram of the hydraulic support;

[0039] Figure 4 Construct diagrams for the structural parameters and coordinate system of the main frame of the hydraulic support;

[0040] Figure 5 This is a flow chart for calculating the position coordinates of each identification point on the main frame of the hydraulic support. DETAILED DESCRIPTION

[0041] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] It should be clear that in order to more clearly illustrate the present invention, many technical details are described in the following specific embodiments. Those skilled in the art should understand that the present invention can also be implemented without some of the details. In addition, in order to highlight the main idea of ​​the present invention, some methods, means, parts and their applications well known to those skilled in the art are not described in detail, but this does not affect the implementation of the present invention. The embodiments described herein are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0043] Since the hydraulic support mainly relies on the column jack and the balance jack to adjust the support posture of the hydraulic support, the present invention proposes an intelligent solution method for the support posture of a two-column shielding hydraulic support, taking the column jack stroke and the balance jack stroke of the hydraulic support as independent variables, and intelligently solving the support posture of the hydraulic support in different support states (when the column jack and the balance jack take different stroke values) according to the structural parameters of the hydraulic support. The method is suitable for solving the support posture and support height of the two-column shielding hydraulic support, and further can be used to control the posture of the hydraulic support. The measurement method includes the following steps:

[0044] S001, according to the main structure of the hydraulic support, extract the main frame structure parameters of the hydraulic support, see Figure 1-3 As shown, the dimensions of the main frame of the hydraulic support are measured and obtained;

[0045] Specifically, for the convenience of description, the connection points of the hydraulic support skeleton structure are marked with English letters, from A to U, a total of 21 points, see Figure 2 , Figure 3 As shown, point A is the hinge point between the column jack and the top beam, point G is the hinge point between the column jack and the base, point B is the hinge point between the balance jack and the top beam, point D is the hinge point between the balance jack and the shield beam, point C is the hinge point between the top beam and the shield beam, point E is the hinge point between the shield beam and the front connecting rod, point F is the hinge point between the shield beam and the rear connecting rod, point H is the hinge point between the front connecting rod and the base, and point I is the hinge point between the rear connecting rod and the base;

[0046] In addition, K, L, and M are fixed connection points, indicating the vertical projection points from the hinge points of the column jack, balance jack, shield beam and top beam to the upper surface of the top beam; N, O, and P are fixed connection points, indicating the vertical projection points from the hinge points of the balance jack, front link, rear link and shield beam to the upper surface of the shield beam; R, S, and T are fixed connection points, indicating the vertical projection points from the hinge points of the column jack, front link, rear link and base to the lower surface of the base; Point J indicates the front end point of the upper surface of the top beam, and Points Q and U are the two end points of the lower surface of the base, see Figure 3 shown.

[0047] By measuring the distance between the marking points of the main frame of the hydraulic support, the size parameters of the main frame of the hydraulic support can be obtained. For the convenience of expression, the length between the marking points is expressed as to It is shown in Table 1;

[0048] Table 1 Symbols indicating the distances between the marking points on the main frame of the hydraulic support

[0049] Serial number length symbol Serial number length symbol 1 AG #timg# 14 AK #timg# 2 AB #timg# 15 BJ #timg# 3 BC #timg# 16 BK #timg# 4 BD #timg# 17 AL #timg# 5 CD #timg# 18 AM #timg# 6 DE #timg# 19 BL #timg# 7 EF #timg# 20 BM #timg# 8 CE #timg# 21 EN #timg# 9 CF #timg# 22 FN #timg# 10 EH #timg# 23 DO #timg# 11 FI #timg# 24 FO #timg# 12 AC #timg# 25 DP #timg# 13 AJ #timg# 26 EP #timg#

[0050] When the frame structure parameters of the hydraulic support are determined, only the stroke of the column jack in Table 1 above is , Balance jack travel is a variable, and the rest are fixed values. The distance values ​​between each identification point are recorded and saved.

[0051] S002, monitor and obtain the stroke of the column jack , Balance jack travel ;

[0052] Specifically, in one embodiment, a travel sensor is installed inside the column jack and the balance jack to monitor the travel of the column jack. , Balance jack travel Conduct real-time monitoring;

[0053] In addition, machine vision, laser ranging and other methods can also be used to measure the stroke of the column jack. , Balance jack travel Conduct real-time monitoring.

[0054] S003, establish a plane rectangular coordinate system, see Figure 4 As shown, according to the distance relationship between the identification points of the main frame of the hydraulic support, a set of equations for solving the coordinate values ​​of the identification points of the main frame of the hydraulic support is constructed;

[0055] Specifically, in order to facilitate the solution, the projection of the lower surface of the hydraulic support base on the coordinate plane is taken as the x-axis, and the vertical projection line of the top beam front end point J on the x-axis when the hydraulic support is at the lowest support height is taken as the y-axis to establish the xoy plane rectangular coordinate system;

[0056] According to the established xoy plane rectangular coordinate system, the coordinate parameters of each identification point of the main frame of the hydraulic support are determined, as shown in Table 2;

[0057] Table 2 Coordinate parameters of each identification point of the main frame of the hydraulic support

[0058] Serial number Identifier coordinate Serial number Identifier coordinate 1 A (#timg#,#timg#) 12 L (#timg#,#timg#) 2 B (#timg#,#timg#) 13 M (#timg#,#timg#) 3 C (#timg#,#timg#) 14 N (#timg#,#timg#) 4 D (#timg#,#timg#) 15 O (#timg#,#timg#) 5 E (#timg#,#timg#) 16 P (#timg#,#timg#) 6 F (#timg#,#timg#) 17 Q (#timg#,#timg#) 7 G (#timg#,#timg#) 18 R (#timg#,#timg#) 8 H (#timg#,#timg#) 19 S (#timg#,#timg#) 9 I (#timg#,#timg#) 20 T (#timg#,#timg#) 10 J (#timg#,#timg#) 21 U (#timg#,#timg#) 11 K (#timg#,#timg#) 22 V (#timg#,#timg#)

[0059] According to the distance relationship between the marking points of the main structure of the hydraulic support, a set of equations is constructed to solve the position coordinates of each marking point. The solution steps are as follows: Figure 5 As shown:

[0060] T01, according to the coordinates of the top beam, column jack, balance jack, shield beam, front link, rear link, and hinge points (A, B, C, D, E, F, G, H, I) of the hydraulic support, establish the equilibrium equation group, as shown in formula (1):

[0061] (1);

[0062] According to the xoy plane rectangular coordinate system established above, the coordinate values ​​of points G, H, and I are fixed values ​​and will not change with the support posture of the hydraulic support. The coordinate values ​​of points A, B, C, D, E, and F are variable values ​​and will change with the stroke of the column jack and the balance jack.

[0063] According to the above formula (1), the stroke of the column jack monitored in step S002 is , Balance jack travel Substituting into the above formula, we can determine the coordinate values ​​of points A, B, C, D, E, and F to solve the expression;

[0064] T02, based on the coordinate values ​​of points A and B, and the distance relationship between the marking points on the top beam, construct a set of equations to solve the coordinates of points J, K, M, and L, as shown in formula (2):

[0065] (2)

[0066] Specifically, since the distances between the marking points on the top beam of the hydraulic support are fixed values, that is, the distances from point A to points J, K, L, and M are fixed values, and the distances from point B to points J, K, L, and M are also fixed values, therefore, according to the position coordinates of points A and B, we can construct a set of equations for solving the coordinates of points J, K, M, and L, formula (2), thereby solving the coordinate values ​​of points J, K, M, and L;

[0067] T03, based on the coordinate values ​​of points D, E, and F, and the distance relationship between the marking points on the shield beam, a set of equations for solving the coordinates of points N, O, and P is constructed, as shown in formula (3):

[0068] (3)

[0069] Specifically, since the distances between the marking points on the hydraulic support shielding beam are fixed values, that is, the distances from point E to points N and P are fixed values, the distances from point F to points N and O are also fixed values, and the distances from point D to points O and P are fixed values, according to the position coordinates of points D, E, and F, we can construct a set of equations for solving the coordinates of points N, O, and P, formula (3), and thus solve the coordinate values ​​of points N, O, and P.

[0070] S004, solving the coordinate values ​​of each identification point of the main frame of the hydraulic support;

[0071] Specifically, since the above equations are all multivariate quadratic equations, it is difficult to solve the equations directly. Therefore, the Newton iteration method, the chord cut method, and the Broyden method are used to solve the coordinate values ​​of each identification point of the main frame of the hydraulic support;

[0072] In order to improve the efficiency of solving the hydraulic support posture, programming software (such as Python, MATLAB, etc.) can be used for solving, and the monitored column jack stroke value and balance jack stroke value can be transmitted to the software system, thereby realizing real-time intelligent solution of the position of each coordinate point.

[0073] S005, according to the coordinate values ​​of each identification point of the main frame structure of the hydraulic support, solve the angles between the top beam, the shield beam, the front connecting rod, the rear connecting rod and the lower surface of the base of the hydraulic support;

[0074] Specifically, the angle between the top beam and the base is calculated based on the coordinate values ​​of points K and L: :

[0075] (4);

[0076] when When it is positive, that is, the ordinate of point L is greater than that of point K, it means that the top beam of the hydraulic support is "lowering"; when When it is a negative value, that is, the ordinate of point L is less than that of point K, it means that the top beam of the hydraulic support is "warped up";

[0077] According to the coordinate values ​​of points C and P, the angle between the shield beam and the base is calculated. Figure 4 The coordinate system shown in Figure 1 shows that the angle between the shield beam and the base (negative direction of the x-axis) is :

[0078] (5);

[0079] According to the coordinate values ​​of points E and H, the angle between the front link and the base is calculated. Figure 4 The coordinate system shown in Figure 2 shows that the angle between the front link and the base (positive direction of the x-axis) is :

[0080] (6);

[0081] According to the coordinate values ​​of points F and I, the angle between the rear connecting rod and the base is calculated. Figure 4 The coordinate system shown in Figure 2 shows that the angle between the rear link and the base (positive direction of the x-axis) is :

[0082] (7).

[0083] S006, determining the support posture of the hydraulic support according to the calculated angle values ​​between the hydraulic support top beam, the shield beam, the front connecting rod, the rear connecting rod and the lower surface of the base.

[0084] In summary, the intelligent solution method for the support posture of the two-column shielding hydraulic support provided by the present invention collects the stroke monitoring values ​​of the column jack and the balance jack, constructs a multivariate multi-order equation group according to the length relationship between the parameters of the main skeleton of the hydraulic support, solves the position coordinates of each identification point of the main skeleton of the hydraulic support, and calculates the angles between the top beam, shielding beam, front connecting rod, rear connecting rod and the base of the hydraulic support through the position coordinates of each identification point of the main skeleton of the hydraulic support. Since the stroke of the top beam jack and the balance jack of the hydraulic support are easy to monitor, and the monitoring results are highly accurate, the stable value of the support posture of the hydraulic support can be obtained, which has the advantages of easy online monitoring, simple monitoring data processing, high accuracy, and low cost, and can provide accurate posture data support for further control of the support posture of the hydraulic support in the future, so as to improve the control accuracy.

[0085] The above description is only the principle and preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this field, several other modifications can be made based on the principle of the present invention, which should also be considered as the protection scope of the present invention.

Claims

1. A method for intelligently calculating the support posture of a two-column shielding hydraulic support, characterized in that: Includes steps: S001, according to the main structure of the hydraulic support, extract the structural parameters of the main frame of the hydraulic support, and measure and obtain the size of the main frame of the hydraulic support; wherein: the structural parameters of the main frame of the hydraulic support are obtained by measuring the distance between the marking points on the main frame of the hydraulic support, the hinge point between the column jack and the top beam is point A, the hinge point between the column jack and the base is point G, the hinge point between the balance jack and the top beam is point B, the hinge point between the balance jack and the shielding beam is point D, the hinge point between the top beam and the shielding beam is point C, the hinge point between the shielding beam and the front connecting rod is point E, the hinge point between the shielding beam and the rear connecting rod is point F, the hinge point between the front connecting rod and the base is point H, and the hinge point between the rear connecting rod and the base is point I; In addition, K, L, and M are fixed connection points, which respectively represent the vertical projection points from the hinge points of the column jack, the balance jack, the shielding beam and the top beam to the upper surface of the top beam; N, O, and P are fixed connection points, which respectively represent the vertical projection points from the hinge points of the balance jack, the front connecting rod, the rear connecting rod and the shielding beam to the upper surface of the shielding beam; R, S, and T are fixed connection points, which respectively represent the vertical projection points from the hinge points of the column jack, the front connecting rod, the rear connecting rod and the base to the lower surface of the base; Point J represents the front end point of the upper surface of the top beam, and Points Q and U represent the two end points of the lower surface of the base. For the convenience of expression, the length between each marking point is l1 to l 26 As shown in Table 1: Table 1 Symbols indicating the distances between the marking points on the main frame of the hydraulic support S002, monitoring and obtaining the stroke of the column jack and the stroke of the balance jack; S003, establish a plane rectangular coordinate system, and construct a set of equations for solving the coordinate values ​​of each identification point of the main frame of the hydraulic support according to the distance relationship between each identification point of the main frame of the hydraulic support; wherein: the projection of the lower surface of the hydraulic support base on the coordinate plane is taken as the x-axis, and the vertical projection line of the front end point J of the top beam when the hydraulic support is at the lowest support height on the x-axis is taken as the y-axis, and the xoy plane rectangular coordinate system is established; According to the established xoy plane rectangular coordinate system, the coordinate parameters of each identification point of the main frame of the hydraulic support are determined, as shown in Table 2; Table 2 Coordinate parameters of each identification point of the main frame of the hydraulic support ； S004, solving the coordinate values ​​of each identification point of the main frame of the hydraulic support; S005, according to the coordinate values ​​of each identification point of the main frame structure of the hydraulic support, respectively solve the angles between the top beam, the shield beam, the front connecting rod, the rear connecting rod of the hydraulic support and the lower surface of the base; S006, determining the support posture of the hydraulic support according to the calculated angle values ​​between the top beam, the shield beam, the front connecting rod, the rear connecting rod and the lower surface of the base; The method of constructing a set of equations for solving the coordinate values ​​of each identification point of the main frame of the hydraulic support mainly includes: T01, according to the coordinates of the hinge points (A, B, C, D, E, F, G, H, I) of the top beam, column jack, balance jack, shield beam, front link, rear link and base of the hydraulic support, establish the equilibrium equation group: Substituting the stroke of the monitored column jack and the stroke of the balance jack into the above formula, the coordinate values ​​of points A, B, C, D, E, and F can be determined; T02, based on the coordinate values ​​of points A and B, and the distance relationship between the marking points on the top beam, construct a set of equations to solve the coordinates of points J, K, M, and L: T03, based on the coordinate values ​​of points D, E, and F, and the distance relationship between the marking points on the shield beam, construct a set of equations to solve the coordinates of points N, O, and P:

2. According to claim 1, a method for intelligently calculating the support posture of a two-column shielding hydraulic support is characterized in that: The stroke l1 of the column jack and the stroke l4 of the balance jack are monitored and acquired by installing stroke sensors inside the column jack and the balance jack, or by using machine vision or laser ranging methods.

3. According to claim 1, a method for intelligently calculating the support posture of a two-column shielding hydraulic support is characterized in that: The coordinate values ​​of the marking points of the main frame of the hydraulic support are solved mainly by Newton iteration method, chord cut method and Broyden method.

4. According to claim 1, a method for intelligently calculating the support posture of a two-column shielding hydraulic support is characterized in that: The method of respectively calculating the angles between the top beam, the shield beam, the front connecting rod, the rear connecting rod and the lower surface of the base of the hydraulic support includes: According to the coordinate values ​​of points K and L, the angle between the top beam and the base is calculated as α: When α is a positive value, that is, the ordinate of point L is greater than the ordinate of point K, it means that the top beam of the hydraulic support is "lowered"; when α is a negative value, that is, the ordinate of point L is less than the ordinate of point K, it means that the top beam of the hydraulic support is "upward"; The angle between the shield beam and the base is calculated based on the coordinate values ​​of points C and P, and the angle between the shield beam and the base in the negative direction of the x-axis is β: The angle between the front link and the base is calculated based on the coordinate values ​​of points E and H. The angle between the front link and the positive direction of the x-axis of the base is γ: The angle between the rear link and the base is calculated based on the coordinate values ​​of points F and I. The angle between the rear link and the positive direction of the x-axis of the base is δ:

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