Online detection method and system for off-machine assembly process of pipeline

Abstract

The invention belongs to the technical field of aircraft pipeline assembly, and particularly relates to an on-line detection method and system for the off-board assembly process of a pipeline, and the method comprises the following steps: constructing a tightening control model, and initializing model parameters; adjusting the conduit and the joint to an initial state and applying tightening torque; reading tightening process information in real time and drawing a tightening curve broken line graph; the initial assembly normalization is judged in real time; fitting a linear segment slope kj in real time; the standardability of the assembly process is judged in real time; the tightening torque maximum value Tmax and the tightening angle maximum value Amax are detected in real time; calculating an assembly result in real time; and assembling reliability is detected in real time. According to the invention, an assembling tool with torque acquisition and angle acquisition is utilized to acquire tightening torque and rotation angle in the assembling process, and data information in the tightening process is read in real time. And data information of the tightening process is input into the tightening control model, and meanwhile, external assembly control parameters and boundary parameters of the guide pipe machine are set, so that real-time online detection of the whole assembly process of the guide pipe is realized.

Description

Technical Field

[0001] This application belongs to the technical field of aircraft pipeline assembly, and specifically relates to an on-line detection method and system for the off-aircraft pipeline assembly process. Background Art

[0002] The aviation pipeline system is one of the most important systems of an aircraft, serving as the "blood vessels" and "air ducts" of the aircraft. Its main function is to transport various media, including fuel, hydraulic oil, air, oxygen, nitrogen, etc. During the actual assembly process, due to factors such as limited cabin space, structural obstruction, and lack of fixation, assembly tools often cannot tighten nuts at the standard angle for assembly. Therefore, operators need to pre-assemble some ducts and pipe joints on the ground and then install them on the aircraft as a whole.

[0003] However, at present, the off-aircraft assembly process of ducts usually adopts the method of manual assembly on the ground. Operators fix the ducts by stepping on them or kneeling on them, and then use assembly tools to assemble the nuts. This assembly method has the following deficiencies: (1) It is difficult to effectively fix the ducts, resulting in the ducts often rotating with the rotation of the assembly tools during the ground assembly process; (2) It is difficult to apply force smoothly to assemble the nuts; (3) There is a lack of control during the assembly process, resulting in uneven quality of the pipeline system during ground assembly. Therefore, the current ground assembly has poor quality and low efficiency, making it difficult to ensure the assembly consistency of the aircraft pipeline system and seriously affecting flight safety.

[0004] The prior art, such as the Chinese invention patent with the patent number 202010813177.9 and the name "Aviation Engine Pipeline Assembly Positioning Device and Assembly Method", discloses an aviation engine pipeline assembly positioning device and assembly method, which focuses on the positioning process of a specific single duct of an aviation engine and is only applicable to the assembly of the secondary air intake pipe, with deficiencies such as insufficient generality and adaptability, and cannot meet the assembly requirements of a large number of ducts on the aircraft. Summary of the Invention

[0005] To solve the above problems existing in the prior art, the present invention proposes an on-line detection system and method for the off-aircraft pipeline assembly process, which can not only realize the off-aircraft assembly function but also meet the requirements of real-time control during the pipeline assembly process.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] An on-line detection method for the off-aircraft pipeline assembly process includes the following steps:

[0008] Step S1: Construct a tightening control model and initialize the model parameters;

[0009] The above-mentioned step S1 constructs an off-machine digital assembly tightening control model as shown in formula (1).

[0010] F = a(A0) + b(kS j ) + c(A max ) + d(T max ) (1)

[0011] Among them, F represents the final tightening effect parameter value, a(A0) represents the initial assembly specification value-taking function, b(kS j ) represents the slope stability coefficient kS j value-taking function, c(A max ) represents the maximum tightening angle A max value-taking function, d(T max ) represents the maximum tightening torque T max value-taking function;

[0012] Step S2: Adjust the catheter and the joint to the initial state and apply the tightening torque;

[0013] Step S3: Read the tightening process information in real time and draw a tightening curve broken line graph;

[0014] Step S4: Judge the initial assembly normality in real time;

[0015] Step S5: Fit the slope k of the linear segment in real time j ;

[0016] Step S6: Judge the assembly process normality in real time;

[0017] Step S7: Detect the maximum tightening torque T max and the maximum tightening angle A max ;

[0018] Step S8: Calculate the assembly result in real time;

[0019] Step S9: Detect the assembly reliability in real time.

[0020] Furthermore, the off-machine digital assembly tightening control model includes 4 control parameters and 8 boundary parameters. Among them, the 4 control parameters are used as inputs after being calculated from the data collected during the assembly process, and the 8 boundary parameters are specified in advance by the process personnel; the 4 control parameters are respectively the fitting angle A0, the slope stability coefficient kS j , the maximum tightening angle A max and the maximum tightening torque T max ; the 8 boundary parameters are respectively the fitting torque T0, the lower limit A 0min of the initial assembly specification angle interval, the upper limit A 0max, slope deviation threshold KL, lower limit A1 of the tightening angle range, upper limit A2 of the tightening angle range, lower limit T1 of the tightening torque range, upper limit T2 of the tightening torque range.

[0021] Further, in the step S2, the pipe joint is installed on the fixed support 4-1, the positions of the slider 4-3 and the posture adjustment support mechanism 4-4 are adjusted to make the catheter and the joint in the initial alignment state, and the tightening torque is applied to the outer sleeve nut by using the digital assembly tool 5.

[0022] Further, the step S3 is specifically: continuously apply the tightening torque to rotate the outer sleeve nut, and transmit the applied tightening torque information T i , i = 1, 2, 3, …, m, and the tightening angle information A i , i = 1, 2, 3, …, m, in real time, and construct them into an angle matrix A and a torque matrix T, where m is the number of received time-series data points, and the elements of the angle matrix A and the torque matrix T correspond one by one;

[0023] Where:

[0024]

[0025] Decode and convert the received information, use A as the abscissa and T as the ordinate to draw a line graph, and display the tightening curve line graph in real time.

[0026] Further, the S4 is specifically: given a reference initial torque T0, construct a fitting angle value function e(T s ), and compare the size of the last element T s of the torque matrix T with the reference initial torque T0 in real time; the value of the fitting angle value function e(T m ), when T m is equal to or greater than T0, that is, T m-1 < T0 and T m ≥ T0, the catheter reaches the fitting point, and at this time, the value of T s is the fitting torque, and the last element A s of the angle matrix A is the fitting angle A0.

[0027]

[0028] Furthermore, construct an initial assembly specification value function a(A0):

[0029]

[0030] Judge whether A0 is within the interval [A 0min , A 0max , if A0 < A 0min, then a(A0) = 0. At this time, the fitting angle is too small, indicating that the nut was not fully loosened before the formal assembly of the catheter and was not adjusted to the initial state, which does not meet the initial assembly specification. It is necessary to loosen the nut and re - assemble; if A0 > A 0max , then a(A0) = 0. At this time, the fitting angle is too large, indicating that there is an initial assembly stress in the catheter, which does not meet the initial assembly specification; in this case, return to step S2, loosen the nut, adjust the catheter and the joint to the initial state, and apply the tightening torque to re - assemble. If A0 is within the interval [A 0min , A 0max , then a(A0) = 1, which meets the initial assembly specification.

[0031] Further, the specific steps of step S5 are as follows:

[0032] Continuously apply the tightening torque to rotate the outer nut; the tightening curve is a linear segment after exceeding the point (A s , T s ), and take the recognized fitting angle A s and the fitting torque T s as the starting point of the linear segment; continue to collect the tightening torque information T m and the tightening angle information A m in real - time. Mark the subscript of the last element of the angle matrix A and the torque matrix T after entering the linear segment as M, M ≥ s + 1. Then the last element of the angle matrix A is A M , and the last element of the torque matrix T is T M ;

[0033] Calculate the average value of the angles within the linear interval according to formula (6) Calculate the average value of the torques within the linear interval according to formula (7)

[0034]

[0035] Let j = i - s + 1, and fit the slope k of the linear segment in real - time according to formula (8) j :

[0036]

[0037] where A i (i = s + 1, s + 2, …, M) is the element value of the angle matrix T corresponding to the subscript, and where T i (i = s + 1, s + 2, …, M) is the element value of the torque matrix T corresponding to the subscript.

[0038] Further, the specific steps of step S6 are as follows:

[0039] Calculate the slope stability coefficient kS in real - time through formula (9)j :

[0040]

[0041] Among them

[0042]

[0043] Define the slope stability coefficient kS j Value function b(kS j ):

[0044]

[0045] Set the slope deviation threshold KL. If the current kS j > KL, then b(kS j ) = 0, indicating that the curve slope has deviated significantly and there are problems with the assembly specification. In this case, return to step S2, loosen the nut, adjust the catheter and the connector to the initial state, and apply the tightening torque to reassemble; if the current kS j ≤ KL, then b(kS j ) = 1, indicating that the slope is in a stable range and the assembly process has better specification.

[0046] Furthermore, step S7 is specifically as follows:

[0047] Continuously apply the tightening torque to rotate the outer nut. Mark the subscript of the last element of the angle matrix A and the torque matrix T after entering the linear segment as M, where M ≥ s + 1. Then the maximum tightening angle A max and the maximum tightening torque T max are calculated according to formulas (12) and (13) respectively;

[0048] a max = max (a1, a2,..., a s ,..., a M ) (12)

[0049] T max = max (T1, T2,..., T s ,..., T M ) (13).

[0050] Furthermore, the specific step S8 is as follows:

[0051] Taking the angle A as the abscissa and the torque T as the ordinate, construct a planar region. Set the effective angle range as [A1, A2] and the effective torque range as [T1, T2]. Construct a boundary rectangular region RectValid through the coordinate points (A1, T1), (A2, T1), (A1, T2), and (A2, T2).

[0052] Furthermore, construct the maximum tightening angle value-taking function c(A max ) as shown in formula (14);

[0053]

[0054] When A max < A1, c(A max ) = 0; when A max > A2, c(A max ) = 1; when A1 ≤ A max ≤ A2, c(A max ) = 2;

[0055] Construct the maximum tightening torque value-taking function c(A max ), as shown in formula (15):

[0056]

[0057] When T max < T1, d(T max ) = 0; when T max > T2, d(T max ) = 1; when T1 ≤ T max ≤ T2, d(T max ) = 2.

[0058] Furthermore, the specific content of step S9 is as follows:

[0059] Calculate the result of the constructed tightening control model from formula (1). The constructed boundary rectangular region RectValid divides the planar region into 9 parts, corresponding to 9 possible tightening situations as follows:

[0060] (1) Situation 1: c(A max ) = 0, d(T max ) = 0, and it can be calculated that F = 2; in this situation, A max < A1, T max < T1, so it is considered that this situation has not reached the final tightening state. In this situation, the system automatically jumps to step S5 to continue real-time detection of the tightening process.

[0061] (2) Situation 2: c(A max ) = 1, d(Tmax ) = 0, it can be calculated that F = 3; in this case, A max > A2, T max < T1, so it is considered that this case does not meet the tightening requirements. In this case, it is necessary to return to step S2, adjust the catheter and the connector to the initial state and apply the tightening torque.

[0062] (3) Case 3: c(A max ) = 0, d(T max ) = 1, it can be calculated that F = 3; in this case, A max < A1, T max > T2, so it is considered that this case does not meet the tightening requirements. In this case, it is necessary to return to step S2, adjust the catheter and the connector to the initial state and apply the tightening torque.

[0063] (4) Case 4: c(A max ) = 1, d(T max ) = 1, it can be calculated that F = 4; in this case, A max > A2, T max > T2, so it is considered that this case does not meet the tightening requirements. In this case, it is necessary to return to step S2, adjust the catheter and the connector to the initial state and apply the tightening torque.

[0064] (5) Case 5: c(A max ) = 0, d(T max ) = 2, it can be calculated that F = 4; in this case, A max < A1, T1 ≤ T max ≤ T2, so it is considered that this case has not reached the final tightening state. In this case, the system automatically jumps to step S5 to continue real-time detection of the tightening process.

[0065] (6) Case 6: c(A max ) = 2, d(T max ) = 0, it can be calculated that F = 4; in this case, A1 ≤ A max ≤ A2, T max < T1 and the angle reaches the set process parameter range, so it is considered that this case has not reached the final tightening state. In this case, the system automatically jumps to step S5 to continue real-time detection of the tightening process.

[0066] (7) Case 7: c(A max ) = 1, d(T max ) = 2, it can be calculated that F = 5; in this case, A max > A2, T1 ≤ T max ≤ T2, and the torque reaches the set process parameter range, so it is considered that this case does not meet the tightening requirements. In this case, it is necessary to return to step S2, adjust the catheter and the connector to the initial state and apply the tightening torque.

[0067] (8) Case 8: c(A max ) = 2, d(T max ) = 1, and it can be calculated that F = 5; in this case, A1 ≤ A max ≤ A2, and T max > T2 reaches the set process parameter range, so it is considered that this case does not meet the tightening requirements. In this case, it is necessary to return to step S2, adjust the catheter and the joint to the initial state and apply the tightening torque.

[0068] (9) Case 9: c(A max ) = 2, d(T max ) = 2, and it can be calculated that F = 6; in this case, A1 ≤ A max ≤ A2, T1 ≤ T max ≤ T2, so it is considered that this case meets the tightening requirements. In this case, the tightening result has met the requirements, and the tightening operation is ended. Since the current real-time detection result meets the requirements, the tightening operation is stopped.

[0069] An on-line detection system for the off-machine assembly process of pipelines, comprising a controller, a display, a movable vehicle body, an assembly table and a digital assembly tool;

[0070] The controller is used to run an on-line detection method for the off-machine assembly process of pipelines, receive the assembly process information transmitted by the digital assembly tool, and transmit the received assembly process information to the display;

[0071] The display is used to display the assembly process data and the detection result in real time;

[0072] The movable vehicle body is used to place the controller, the display and the assembly table;

[0073] The assembly table is used to implement the off-machine auxiliary assembly of the catheter and the joint;

[0074] The digital assembly tool is used to apply a tightening torque to the outer sleeve nut.

[0075] Further, the assembly table includes a fixed support, a guide rail, a slider, a pose adjustment support mechanism and a tabletop; the tabletop is provided with a fixed support and a guide rail, the slider is installed on the guide rail, and the pose adjustment support mechanism is installed on the slider;

[0076] The fixed support is used to fix the pipe joint;

[0077] The guide rail is used to support the slider;

[0078] The slider is used to support the pose adjustment support mechanism;

[0079] The pose adjustment support mechanism supports the catheter to be assembled by adjusting its own pose.

[0080] Threaded connection holes are reserved on the desktop.

[0081] The advantages of this application are as follows:

[0082] 1. This invention is mainly used for real-time detection of the assembly process of ducts during off-aircraft pipeline assembly. On the one hand, it solves the quality problems such as surface damage caused by off-aircraft ground assembly of aviation pipelines. On the other hand, it solves the quality problems such as insufficient assembly torque and excessive assembly torque during the assembly process of the pipeline system.

[0083] 2. Aiming at the problems existing in the current off-aircraft manual assembly of aviation pipelines, such as insufficient pre-tightening force, cumbersome operation, lack of process control, and low assembly quality, this invention designs an on-line detection system for the off-aircraft assembly process of pipelines and provides an on-line detection method for the off-aircraft assembly process of pipelines, which can realize the control of the off-aircraft assembly process of aircraft pipelines and meet the requirements of efficient and high-quality assembly.

[0084] 3. This invention provides an on-line detection system for off-aircraft assembly process with high integration, simplicity and efficiency, constructs a tightening control model for the pipeline assembly process, and provides an on-line detection method for the off-aircraft assembly process. By using an assembly tool with torque acquisition and angle acquisition, the tightening torque and rotation angle during the assembly process are collected, and the tightening process data information is read in real time. The tightening process data information is input into the tightening control model, and at the same time, the off-aircraft assembly control parameters and boundary parameters of the duct are set, realizing real-time on-line detection of the whole process of duct assembly, including the normality of initial assembly, the normality of process assembly, and the reliability of assembly results. Applying the technical solution of this invention for duct assembly can transfer the ducts assembled in the narrow space on the aircraft to off-aircraft for assembly, and at the same time can strictly control each link of the pipeline assembly process, effectively improving the assembly quality of the duct.

[0085] 4. An on-line detection system for the off-aircraft assembly process of pipelines provided by this invention innovatively realizes the transformation of the duct assembly work in the narrow space on the aircraft to off-aircraft digital assembly work, overcomes the limiting conditions such as the narrow space in the aircraft cabin and the occlusion of part finished products, and solves the problems of poor assembly quality and low assembly reliability of ducts in the narrow space on the aircraft at the present stage.

[0086] 5. An on-line detection system for the off-aircraft assembly process of pipelines provided by this invention innovatively realizes the digital assembly of aviation ducts, realizes the on-line collection and analysis of assembly process data, and solves the problem that the assembly process cannot be traced when duct assembly quality problems occur at the present stage.

[0087] 6. An on-line detection method for the off-machine assembly process of pipelines provided by the present invention innovatively constructs a parametric tightening control model, establishes a feedback mechanism for the assembly quality at each stage of the pipeline assembly process, realizes the full-automatic parametric analysis and evaluation of the assembly process data, and at the same time realizes the assembly quality control of the entire assembly process, effectively improving the pipeline assembly quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] Figure 1 is an on-line detection system for the off-machine assembly process of pipelines.

[0089] Figure 2 is an enlarged view of the assembly desktop 4 of the on-line detection system for the off-machine assembly process of pipelines.

[0090] Figure 3 is a flowchart of an on-line detection method for the off-machine assembly process of pipelines.

[0091] Figure 4 is a schematic diagram of the key parameters of the tightening control model and the assembly process data.

[0092] Figure 5 is a diagram for dividing the reliability area of the assembly result.

[0093] Figure 6 is a schematic diagram of assembly state 1.

[0094] Figure 7 is a graph of the real-time change trend of the slope of assembly state 1.

[0095] Figure 8 is a graph of the change trend of the slope stability coefficient of assembly state 1.

[0096] Figure 9 is a graph of the assembly reliability detection result of assembly state 1.

[0097] Figure 10 is a schematic diagram of assembly state 2.

[0098] Figure 11 is a graph of the real-time change trend of the slope of assembly state 2.

[0099] Figure 12 is a graph of the change trend of the slope stability coefficient of assembly state 2.

[0100] Figure 13 is a graph of the assembly reliability detection result of assembly state 2.

[0101] Figure 14 is a schematic diagram of assembly state 3.

[0102] Figure 15 is a graph of the real-time change trend of the slope of assembly state 3.

[0103] Figure 16 It is a graph showing the changing trend of the slope stability coefficient in Assembly State 3.

[0104] Figure 17 It is a graph showing the results of the assembly reliability test in Assembly State 3. Detailed implementation manners

[0105] To make the objectives, technical solutions and advantages of the embodiments of the invention clearer, the technical solutions in the embodiments of the invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the invention. Obviously, the described embodiments are some, but not all, of the embodiments of the invention. Generally, the components of the embodiments of the invention described and illustrated herein can be arranged and designed in various different configurations.

[0106] Therefore, the following detailed description of the embodiments of the invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the invention without creative efforts shall fall within the protection scope of the invention.

[0107] It should be noted that: like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0108] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "vertical", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is customarily placed during use, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0109] The aircraft surface feature segmentation method based on contour constraint optimization of the present invention completes the segmentation task of the target in the image based on a deep learning network. The feature extraction backbone network learns the feature information in the image, and then based on this feature information, fits the outer contour constraint of the target and preliminarily segments the target to be segmented in the image. Finally, the target contour constraint is used to optimize the segmentation result to achieve high-precision segmentation of each target instance in the image.

[0110] Embodiment 1

[0111] As Figure 3As shown in the figure, an on-line detection method for the off-machine assembly process of a pipeline includes the following steps:

[0112] Step S1: Construct a tightening control model and initialize the model parameters;

[0113] In step S1, an off-machine digital assembly tightening control model as shown in formula (1) is constructed.

[0114] F = a(A0) + b(kS j ) + c(A max ) + d(T max ) (1)

[0115] Where F represents the final tightening effect parameter value, a(A0) represents the initial assembly specification value-taking function, b(kS j ) represents the slope stability coefficient kS j value-taking function, c(A max ) represents the maximum tightening angle A max value-taking function, d(T max ) represents the maximum tightening torque T max value-taking function;

[0116] Step S2: Adjust the catheter and the joint to the initial state and apply a tightening torque;

[0117] Step S3: Read the tightening process information in real time and draw a tightening curve broken line graph;

[0118] Step S4: Judge the initial assembly standardization in real time;

[0119] Step S5: Fit the slope k of the linear segment in real time j ;

[0120] Step S6: Judge the assembly process standardization in real time;

[0121] Step S7: Detect the maximum tightening torque T max and the maximum tightening angle A max ;

[0122] Step S8: Calculate the assembly result in real time;

[0123] Step S9: Detect the assembly reliability in real time.

[0124] Example 2

[0125] As Figure 3 shown in the figure, an on-line detection method for the off-machine assembly process of a pipeline includes the following steps:

[0126] Step S1: Construct a tightening control model and initialize the model parameters;

[0127] The step S1 constructs an off-machine digital assembly tightening control model as shown in formula (1).

[0128] F = a(A0) + b(kS j ) + c(A max ) + d(T max ) (1)

[0129] Where F represents the final tightening effect parameter value, a(A0) represents the initial assembly specification value-taking function, b(kS j ) represents the slope stability coefficient kS j value-taking function, c(A max ) represents the maximum tightening angle A max value-taking function, d(T max ) represents the maximum tightening torque T max value-taking function;

[0130] Step S2: Adjust the catheter and the connector to the initial state and apply the tightening torque;

[0131] Step S3: Read the tightening process information in real time and draw a tightening curve broken line graph;

[0132] Step S4: Judge the initial assembly normality in real time;

[0133] Step S5: Fit the linear segment slope k j ;

[0134] Step S6: Judge the assembly process normality in real time;

[0135] Step S7: Detect the maximum tightening torque T max and the maximum tightening angle A max ;

[0136] Step S8: Calculate the assembly result in real time;

[0137] Step S9: Detect the assembly reliability in real time.

[0138] The off-machine digital assembly tightening control model includes 4 control parameters and 8 boundary parameters. Among them, the 4 control parameters are calculated from the data collected during the assembly process and used as inputs, and the 8 boundary parameters are specified in advance by the process personnel; the 4 control parameters are respectively the fitting angle A0, the slope stability coefficient kS j , the maximum tightening angle A max and the maximum tightening torque T max ; the 8 boundary parameters are respectively the fitting torque T0, the lower limit A 0min of the initial assembly specification angle interval, the upper limit A 0max of the initial assembly specification angle interval, slope deviation threshold KL, lower limit A1 of the tightening angle range, upper limit A2 of the tightening angle range, lower limit T1 of the tightening torque range, upper limit T2 of the tightening torque range.

[0139] In the step S2, install the pipe joint on the fixed support 4-1, adjust the positions of the slider 4-3 and the posture adjustment support mechanism 4-4 to make the catheter and the joint in the initial centering state, and apply a tightening torque to the outer sleeve nut by using the digital assembly tool 5.

[0140] The step S3 is specifically as follows: Continuously apply a tightening torque to rotate the outer sleeve nut, and the digital assembly tool 5 transmits the applied tightening torque information T i , i = 1, 2, 3, …, m, and the tightening angle information A i , i = 1, 2, 3, …, m to the controller 1 in real time, and construct an angle matrix A (as shown in formula (2)) and a torque matrix T (as shown in formula (3)), where m is the number of received time series data points, and the elements of the angle matrix A and the torque matrix T correspond one by one;

[0141] Where:

[0142]

[0143] The controller 1 decodes and converts the received information, uses A as the abscissa and T as the ordinate to draw a line graph, and displays the tightening curve line graph in real time on the display 2.

[0144] The S4 is specifically as follows: Given a reference initial torque T0, as shown in formula (4), construct a fitting angle value function e(T s ), and compare the size of the last element T s of the torque matrix T with the reference initial torque T0 in real time; the value of the fitting angle value function e(T m ) is as shown in Figure 4 . When T m is equal to or greater than T0, that is, T m-1 < T0 and T m ≥ T0, the catheter reaches the fitting point, and at this time, the value of T s is the fitting torque. Since the angle matrix A and the torque matrix T correspond one by one, the last element A s of the angle matrix A is the fitting angle A0.

[0145]

[0146] According to formula (5), construct an initial assembly specification value function a(A0):

[0147]

[0148] Determine whether A0 is within the interval [A 0min , A 0max . If A0 < A 0min , then a(A0) = 0. At this time, the fitting angle is too small, indicating that the catheter was not fully loosened before formal assembly and was not adjusted to the initial state, not meeting the initial assembly specification. The nut needs to be loosened and reassembled. If A0 > A 0max , then a(A0) = 0. At this time, the fitting angle is too large, indicating that there is an initial assembly stress in the catheter, not meeting the initial assembly specification, and "Does not meet the initial assembly specification" is output in the display 2. In this case, return to step S2, loosen the nut, adjust the catheter and the joint to the initial state, and apply a tightening torque to reassemble. If A0 is within the interval [A 0min , A 0max , then a(A0) = 1, meeting the initial assembly specification, and "Meets the initial assembly specification" is output in the display 2.

[0149] The specific steps of step S5 are as follows:

[0150] Continuously apply a tightening torque to rotate the outer nut; as Figure 4 shown, the shape of the tightening curve after exceeding the point (A s , T s ) is a linear segment, and the fitting angle A s and the fitting torque T s identified according to formula (4) are used as the starting point of the linear segment; continue to collect the tightening torque information T m and the tightening angle information A m in real time. Mark the subscript of the last element of the angle matrix A and the torque matrix T after entering the linear segment as M, M ≥ s + 1. Then the last element of the angle matrix A is A M , and the last element of the torque matrix T is T M ;

[0151] Calculate the average value of the angles within the linear interval according to formula (6) Calculate the average value of the torques within the linear interval according to formula (7)

[0152]

[0153] Let j = i - s + 1, and fit the slope k of the linear segment in real time according to formula (8) j :

[0154]

[0155] where A i (i = s + 1, s + 2,..., M) is the element value of the corresponding subscript of the angle matrix T, where Ti (i = s + 1, s + 2, …, M) are the element values of the torque matrix T corresponding to the subscripts.

[0156] The specific steps of step S6 are as follows:

[0157] Calculate the slope stability coefficient kS in real time through formula (9) j :

[0158]

[0159] where

[0160]

[0161] As shown in formula (11), define the slope stability coefficient kS j Value function b(kS j ):

[0162]

[0163] Set the slope deviation threshold KL. If the current kS j > KL, then b(kS j ) = 0, it is considered that the curve slope has deviated significantly, and there are problems with the assembly specification. Output "There are problems with the process assembly specification" on the display 2. In this case, return to step S2, loosen the nut, adjust the catheter and the joint to the initial state, and apply the tightening torque to re - assemble; if the current kS j ≤KL, then b(kS j ) = 1, it is considered that the slope is in a stable range, and the assembly process has good specification. Output "The process assembly specification is good" on the display 2.

[0164] The specific steps of step S7 are as follows:

[0165] Continuously apply the tightening torque to rotate the outer nut. Mark the subscripts of the last elements of the angle matrix A and the torque matrix T after entering the linear segment as M, where M ≥ s + 1. Then the maximum tightening angle A max and the maximum tightening torque T max The calculation formulas are shown in formula (12) and formula (13) respectively. As Figure 4 shown is the theoretical form of a complete curve. During the operation, it is necessary to judge the position of the last point of the curve in the theoretical form. The last element in the fitting stage is As (i.e., A0), and the subscript of the last element in the linear stage is M. As and Ts are the end points of the fitting stage, and As + 1 and Ts + 1 are the starting points of the linear stage.

[0166] A max = max (A1, A2, …, As , …, A M ) (12)

[0167] T max = max(T1, T2, …, T s , …, T M ) (13).

[0168] The specific steps of step S8 are as follows:

[0169] As Figure 4 shown, with angle A as the abscissa and torque T as the ordinate, construct a planar region, set the effective angle range as [A1, A2], and set the effective torque range as [T1, T2]; construct a boundary rectangular region RectValid through the coordinate points (A1, T1), (A2, T1), (A1, T2), (A2, T2).

[0170] Construct the maximum tightening angle value function c(A max ) as shown in formula (14);

[0171]

[0172] When A max < A1, c(A max ) = 0; when A max > A2, c(A max ) = 1; when A1 ≤ A max ≤ A2, c(A max ) = 2;

[0173] Construct the maximum tightening torque value function c(A max ), as shown in formula (15):

[0174]

[0175] When T max < T1, d(T max ) = 0; when T max > T2, d(T max ) = 1; when T1 ≤ T max ≤ T2, d(T max ) = 2.

[0176] The specific steps of step S9 are as follows:

[0177] When this step is executed, the values of a(A0) and b(kS j ) must be 1. Combining the values of c(A max ) and d(T max ), the result of the constructed tightening control model can be calculated from formula (1). AsFigure 5 As shown, the constructed boundary rectangle region RectValid divides the planar region into nine parts, corresponding to nine possible tightening situations, as follows:

[0178] (1) Situation 1: c(A max ) = 0, d(T max ) = 0, and it can be calculated that F = 2; in this situation, A max < A1, T max < T1. Therefore, it is considered that this situation has not reached the final tightening state, and the display 2 outputs "Current state: c = 0, d = 0, neither the angle nor the torque has reached the lower limit of the set parameter range. Please continue to tighten." In this situation, the system automatically jumps to step S5 to continue real-time detection of the tightening process.

[0179] (2) Situation 2: c(A max ) = 1, d(T max ) = 0, and it can be calculated that F = 3; in this situation, A max > A2, T max < T1. Therefore, it is considered that this situation does not meet the tightening requirements, and the display 2 outputs "Current state: c = 1, d = 0, the angle exceeds the upper limit of the set parameter range. Please re-tighten." In this situation, it is necessary to return to step S2 to adjust the catheter and the connector to the initial state and apply the tightening torque.

[0180] (3) Situation 3: c(A max ) = 0, d(T max ) = 1, and it can be calculated that F = 3; in this situation, A max < A1, T max > T2. Therefore, it is considered that this situation does not meet the tightening requirements, and the display 2 outputs "Current state: c = 0, d = 1, the torque exceeds the upper limit of the set parameter range. Please re-tighten." In this situation, it is necessary to return to step S2 to adjust the catheter and the connector to the initial state and apply the tightening torque.

[0181] (4) Situation 4: c(A max ) = 1, d(T max ) = 1, and it can be calculated that F = 4; in this situation, A max > A2, T max > T2. Therefore, it is considered that this situation does not meet the tightening requirements, and the display 2 outputs "Current state: c = 1, d = 1, both the angle and the torque exceed the upper limit of the set parameter range. Please re-tighten." In this situation, it is necessary to return to step S2 to adjust the catheter and the connector to the initial state and apply the tightening torque.

[0182] (5) Situation 5: c(A max ) = 0, d(T max) = 2, it can be calculated that F = 4; in this case, A max <A1, T1 ≤ T max ≤ T2, so it is considered that this case has not reached the final tightening state, and the display 2 outputs "Current state: c = 0, d = 2, the angle has not reached the lower limit of the set process parameter range, the torque has reached the set process parameter range, please continue to tighten". In this case, the system automatically jumps to step S5 to continue real-time detection of the tightening process.

[0183] (6) Case 6: c(A max ) = 2, d(T max ) = 0, it can be calculated that F = 4; in this case, A1 ≤ A max ≤ A2, T max <T1 the angle reaches the set process parameter range, so it is considered that this case has not reached the final tightening state, and the display 2 outputs "Current state: c = 2, d = 0, the angle has not reached the lower limit of the set process parameter range, the torque has reached the set process parameter range, please continue to tighten". In this case, the system automatically jumps to step S5 to continue real-time detection of the tightening process.

[0184] (7) Case 7: c(A max ) = 1, d(T max ) = 2, it can be calculated that F = 5; in this case, A max >A2, T1 ≤ T max ≤ T2, the torque reaches the set process parameter range, so it is considered that this case does not meet the tightening requirements, and the display 2 outputs "Current state: c = 1, d = 2, the angle exceeds the upper limit of the set process parameter range, the torque reaches the set process parameter range, please re-tighten". In this case, it is necessary to return to step S2 to adjust the catheter and the joint to the initial state and apply the tightening torque.

[0185] (8) Case 8: c(A max ) = 2, d(T max ) = 1, it can be calculated that F = 5; in this case, A1 ≤ A max ≤ A2, T max >T2 the angle reaches the set process parameter range, so it is considered that this case does not meet the tightening requirements, and the display 2 outputs "Current state: c = 2, d = 1, the angle reaches the set process parameter range, the torque exceeds the upper limit of the set process parameter range, please re-tighten". In this case, it is necessary to return to step S2 to adjust the catheter and the joint to the initial state and apply the tightening torque.

[0186] (9) Case 9: c(A max ) = 2, d(T max ) = 2, it can be calculated that F = 6; in this case, A1 ≤ A max≤A2, T1 ≤ T max ≤ T2, so it is considered that this situation meets the tightening requirements, and the display 2 outputs "Current status: c = 2, d = 2, both the angle and torque reach the set process parameter range, meeting the tightening requirements, please stop tightening". In this case, the tightening result has met the requirements, and the tightening operation is ended. Since the current real-time detection result meets the requirements, the tightening operation is stopped.

[0187] Embodiment 3

[0188] An on-line detection system for the off-machine assembly process of a pipeline, as Figure 1 shown, includes a controller 1, a display 2, a movable vehicle body 3, an assembly table 4, and a digital assembly tool 5;

[0189] The function of the controller 1 is to run an on-line detection method for the off-machine assembly process of a pipeline provided in Embodiment 1, receive the assembly process information transmitted by the digital assembly tool 5, and transmit the received assembly process information to the display 2;

[0190] The function of the display 2 is to display the assembly process data and detection results in real time;

[0191] The function of the movable vehicle body 3 is to place the controller 1, the display 2, and the assembly table 4; It should be noted that, Figure 1 the movable vehicle body 3 shown is only one example for realizing the effect of the present invention, and other vehicle bodies that can achieve the above functions also belong to the protection scope of the present invention.

[0192] As Figure 2 shown, the assembly table 4 is used for off-machine auxiliary assembly of the conduit and the joint;

[0193] The function of the digital assembly tool 5 is to apply a tightening torque to the outer sleeve nut.

[0194] The assembly table 4 includes a fixed support 4-1, a guide rail 4-2, a slider 4-3, a posture adjustment support mechanism 4-4, and a tabletop 4-5; The tabletop 4-5 is provided with a fixed support 4-1 and a guide rail 4-2, the guide rail 4-2 is provided with a slider 4-3, and the slider 4-3 is provided with a posture adjustment support mechanism 4-4;

[0195] The function of the fixed support 4-1 is to fix the pipe joint; It should be noted that the opening size of the fixed support can be adjusted according to the specifications of the actual joint to be assembled, Figure 1 and the one shown is only an example of one specification.

[0196] The guide rail 4-2 is used to support the slider 4-3. The number of guide rails 4-2 can be increased according to actual usage requirements.

[0197] The slider 4-3 is used to support the posture adjustment support mechanism; the number of sliders 4-3 for support can be increased according to actual usage requirements.

[0198] The posture adjustment support mechanism 4-4 supports the conduit to be assembled by adjusting its own position and posture;

[0199] Threaded connection holes are reserved on the desktop 4-5, and the fixed support 4-1, guide rail 4-2, slider 4-3 and posture adjustment support mechanism 4-4 can be added according to actual usage requirements.

[0200] Embodiment 4

[0201] In this embodiment, 1 straight pipe and 1 straight pipe joint are selected for off-machine assembly. Turn on an on-line detection system for the off-machine assembly process of pipelines described in the present invention, and execute an on-line detection method for the off-machine assembly process of pipelines described in the present invention.

[0202] S1: Construct a tightening control model and initialize the model parameters.

[0203] Construct an off-machine digital assembly tightening control model as shown in formula (16), which includes a total of 4 control parameters and 8 boundary parameters. The 4 control parameters are used as inputs after being calculated from the data collected during the assembly process. The 8 boundary parameters are the adhesion torque T0 = 5.7 N·m, the lower limit A 0min of the initial assembly specification angle range = 30°, the upper limit A 0max of the initial assembly specification angle range = 40°, the slope deviation threshold KL = 0.1, the lower limit A1 = 80° of the tightening angle range, the upper limit A2 = 90° of the tightening angle range, the lower limit T1 = 32 N·m of the tightening torque range, and the upper limit T2 = 38 N·m of the tightening torque range.

[0204] F = a(A0) + b(kS j ) + c(A max ) + d(T max ) (16)

[0205] S2: Adjust the conduit and the joint to the initial state and apply a tightening torque.

[0206] As Figure 6 shown, install the pipe joint on the fixed support 4-1, adjust the slider 4-3 to a suitable position, and lock the position of the sliding table. Adjust the height and angle of the posture adjustment support mechanism 4-4 to make the axis of the conduit coincide with the axis of the pipe joint, realizing the initial alignment of the conduit and the pipe joint. Use the digital assembly tool 5 to apply a tightening torque to the outer nut.

[0207] S3: Read the information during the tightening process in real time and draw a tightening curve broken line graph.

[0208] Continuously apply the tightening torque to rotate the outer sleeve nut. The digital assembly tool 5 transmits the applied tightening torque information and tightening angle information to the controller 1 in real time. The controller 1 constructs the received angle information into an angle matrix A and the received torque information into a torque matrix T. As Figure 6 shown, with A as the abscissa and T as the ordinate, the torque-angle line graph drawn is displayed on the monitor 2 in real time.

[0209] S4: Judge the initial assembly compliance in real time.

[0210] As shown in formula (17), compare the size of the last element T of the torque matrix T in real time s with the bonding torque T0 = 5.7 N·m. Since the 42nd element of the torque matrix satisfies T 42 = 5.76 N·m ≥ T0 = 5.7 N·m, and T 41 <T0, it is determined that the catheter has reached the bonding point. At this time, the last element A of the angle matrix A 42 is the bonding angle A0, that is, s = 42. After calculation, the value of A0 is 35.2°.

[0211] A0 = e(T 42 ) = A 42 (17)

[0212] On this basis, according to formula (5), judge whether A0 is within the interval [A 0min , A 0max , that is, within the interval [30°, 40°]. After calculation, A0 is within the interval [30°, 40°], then a(A0) = 1, which meets the initial assembly specification. Therefore, "meets the initial assembly specification" is output in the monitor 2.

[0213] S5: Fit the slope k of the linear segment in real time j

[0214] Take the data points T 42 and A 42 as the starting point of the linear segment, and calculate the average values of the angle and torque in the linear interval in real time according to formula (18) and formula (19).

[0215]

[0216] Let j = i - 42, and fit the slope k of the linear segment in real time according to formula (20) j , and draw the real-time fitting change graph of the slope.

[0217]

[0218] In this embodiment, M = 92 is selected as the assembly state 1 for illustration, and its schematic diagram is asFigure 6 As shown, calculate the slope fitted at the current moment and plot a real-time change trend graph of the slope. Through the real-time fitting change graph, the change trend of the fitted slope of the linear segment can be analyzed.

[0219] (1) As Figure 7 shown is the real-time change trend graph of the slope when M = 92. At this time, the tightening torque is 16.78 N·m. It can be found that after entering the linear stage, the fitted slope first drops rapidly, reaches a minimum point at about 40°; then gradually rises, reaches a local maximum at about 45°; then continues to drop and reaches the second minimum point at about 47°; after that, the slope gradually increases.

[0220] S6: Real-time judgment of the normality of the assembly process

[0221] Calculate the slope stability coefficient kS in real time through formula (9) and formula (10) j . Through the stability coefficient, the stability of the fitted slope can be effectively judged.

[0222] As Figure 8 shown is the real-time fitting change graph of the slope stability coefficient when M = 92. At this time, the tightening torque is 16.78 N·m. It can be found that the change rule of the slope stability coefficient is that it first increases rapidly, reaches a maximum point at about 40°, and then drops slowly. The slope stability coefficient kS at the current moment 50 = 0.0330, and the historical maximum value kS of the current slope stability coefficient 14 = 0.0442.

[0223] As shown in formula (21), set the slope offset threshold kL to 0.1, then the value of b(kS j ) is as follows:

[0224]

[0225] According to formula (21), it can be known that:

[0226] When M = 92, kS 50 = 0.0330 < 0.1, so b(kS 50 ) = 1; since the historical maximum value kS of the current slope stability coefficient 14 = 0.0442 < 0.1, so the values of b(kS j ) are all 1. From this, it can be considered that the slope is within a stable range, the normality of the assembly process is good, and "The normality of the assembly process is good" is output in the display 2.

[0227] S7: Real-time detection of the maximum tightening torque T max and the maximum tightening angle Amax

[0228] Continuously apply the tightening torque to rotate the outer sleeve nut. When the tightening curve exceeds the fitting torque and fitting angle, the tightening curve enters the linear section. As Figure 6 shown, with A as the abscissa and T as the ordinate, the torque-angle broken line graph drawn is displayed in real time on the display 2. Detect the maximum tightening torque T of the tightening curve in real time according to formula (12) and formula (13) max and the maximum tightening angle A max .

[0229] S8: Calculate the assembly result in real time

[0230] Based on the initialized boundary parameter values, the effective angle range is [A1, A2], that is, [80°, 90°], and the effective torque range is [T1, T2], that is, [32 N·m, 38 N·m]. Construct the boundary rectangular area RectValid through the coordinate points (80°, 32 N·m), (90°, 32 N·m), (80°, 38 N·m), (90°, 38 N·m). According to formula (14) and formula (15), calculate the values of c(A max ) and d(T max ) in real time.

[0231] When M = 92, since A max = 57.9°, T max = 16.78 N·m, so c(A max ) = 0, d(T max ) = 0.

[0232] S9: Detect the assembly reliability in real time

[0233] Based on the values of a(A0), b(kS j ), c(A max ) and d(T max ), calculate the value of F.

[0234] As Figure 9 shown is the real-time detection result of the current state. When M = 92, a(A 42 ) = 1, b(kS 14 ) = 1, c(A max ) = 0, d(T max ) = 0, so the value of F is 2. Since T max = 16.78 N·m < T1 = 32 N·m, which conforms to case 1, so the current state is not tightened in place and needs to be tightened continuously. The output in the display 2 is "Current state: c = 0, d = 0, neither the angle nor the torque reaches the lower limit of the set parameter range. Please continue to tighten."

[0235] Since the real-time detection result is "Please continue to tighten", the on-line detection system automatically jumps to step S5.

[0236] S5: Real-time fitting of the slope k of the linear segment j

[0237] Continue to apply the tightening torque to the pipe joint. In this embodiment, M = 192 is selected as an example of the assembly state 2, and its schematic diagram is as Figure 10 shown. Calculate the slope fitted at the current moment and draw a real-time change trend chart of the slope.

[0238] As Figure 11 shown is the real-time change trend chart of the slope when M = 192. At this time, the tightening torque is 30.98 N·m. It can be found that when M > 92, the fitted line shows a stable upward trend.

[0239] S6: Real-time judgment of the normality of the assembly process

[0240] Calculate the slope stability coefficient kS in real time through formula (9) and formula (10) j .

[0241] As Figure 12 shown is the real-time fitting change chart of the slope stability coefficient when M = 192. At this time, the tightening torque is 30.98 N·m. It can be found that the slope stability coefficient gradually rises again when the angle is about 58°. The slope stability coefficient kS at the current moment 150 = 0.0378, and the historical maximum value kS of the current slope stability coefficient 14 = 0.0442.

[0242] As shown in formula (22), set the slope offset threshold to 0.1, then the value of b(kS j ) is as follows:

[0243]

[0244] It can be known from formula (22) that:

[0245] When M = 192, kS 150 = 0.0378 < 0.1, so b(kS 150 ) = 1; since the historical maximum value kS of the current slope stability coefficient 14 = 0.0442 < 0.1, so the values of b(kS j ) are all 1. From this, it can be considered that the slope is in a stable range, and the normality of the assembly process is good. The display 2 outputs "The normality of the assembly process is good".

[0246] S7: Real-time detection of the maximum tightening torque T maxWith the maximum tightening angle A max

[0247] Continuously apply the tightening torque to rotate the outer sleeve nut. When the tightening curve exceeds the fitting torque and fitting angle, the tightening curve enters the linear segment. As Figure 10 shown, with A as the abscissa and T as the ordinate, the torque-angle broken line graph drawn is displayed in real time on the display 2. Detect the maximum tightening torque T of the tightening curve in real time according to formula (12) and formula (13) max With the maximum tightening angle A max .

[0248] S8: Calculate the assembly result in real time

[0249] Based on the initialized boundary parameter values, the effective angle range is [A1, A2], that is, [80°, 90°], and the effective torque range is [T1, T2], that is, [32 N·m, 38 N·m]. Construct the boundary rectangular area through the coordinate points (80°, 32 N·m), (90°, 32 N·m), (80°, 38 N·m), (90°, 38 N·m). According to formula (14) and formula (15), calculate the values of c(A max ) and d(T max ) in real time.

[0250] When M = 192, since A max = 82.7°, T max = 30.98 N·m, so c(A max ) = 1, d(T max ) = 0.

[0251] S9: Detect the assembly reliability in real time.

[0252] Based on the values of a(A0), b(kS j ), c(A max ) and d(T max ), calculate the value of F.

[0253] As Figure 13 shown is the real-time detection result of the current state. When M = 192, a(A 42 ) = 1, b(kS 14 ) = 1, c(A max ) = 2, d(T max ) = 0, so the value of F is 5. Since T max = 30.98 N·m < T1 = 32 N·m, which conforms to case 6. Therefore, the current state is not tightened in place and needs to be tightened continuously. The output in the display 2 is "Current state: c = 2, d = 0, the angle has not reached the lower limit of the set process parameter range, the torque has reached the set process parameter range, please continue to tighten".

[0254] Since the real-time detection result is "Please continue to tighten", the online detection system automatically jumps to step S5.

[0255] S5: Real-time fitting of the slope k of the linear segment j

[0256] Continue to apply a tightening torque to the pipe joint. In this embodiment, M = 217 is selected as an example of the assembly state 3, and its schematic diagram is as Figure 14 shown. Calculate the slope fitted at the current moment and draw a real-time change trend graph of the slope.

[0257] As Figure 15 shown is the real-time change trend graph of the slope when M = 217. At this time, the tightening torque is 33.35 N·m. It can be found that when M > 192, the fitted line shows a stable upward trend.

[0258] S6: Real-time judgment of the normality of the assembly process

[0259] Calculate the slope stability coefficient kS in real time through formula (9) and formula (10) j .

[0260] As Figure 16 shown is the real-time fitting change graph of the slope stability coefficient when M = 217. At this time, the tightening torque is 33.35 N·m. It can be found that when M > 197, the slope stability coefficient gradually increases. The slope stability coefficient kS at the current moment 175 = 0.0384, and the historical maximum value kS of the current slope stability coefficient 14 = 0.0442.

[0261] As shown in formula (23), set the slope offset threshold to 0.1, then the value of b(kS j ) is as follows:

[0262]

[0263] According to formula (23), it can be known that:

[0264] When M = 217, kS 150 = 0.0384 < 0.1, so b(kS 175 ) = 1; since the historical maximum value kS of the current slope stability coefficient 14 = 0.0442 < 0.1, so the values of b(kS j ) are all 1. From this, it can be considered that the slope is within a stable range, the normality of the assembly process is good, and "The normality of the assembly process is good" is output in the display 2.

[0265] S7: Real-time detection of the maximum tightening torque Tmax and the maximum tightening angle A max

[0266] Continuously apply the tightening torque to rotate the outer sleeve nut. When the tightening curve exceeds the fitting torque and the fitting angle, the tightening curve enters the linear section. As Figure 14 shown, with A as the abscissa and T as the ordinate, the torque-angle broken line graph drawn is displayed in real time on the display 2. Detect the maximum tightening torque T of the tightening curve in real time according to formula (12) and formula (13) max and the maximum tightening angle A max .

[0267] S8: Calculate the assembly result in real time

[0268] Based on the initialized boundary parameter values, the effective angle range is [A1, A2], that is, [80°, 90°], and the effective torque range is [T1, T2], that is, [32 N·m, 38 N·m]. Construct the boundary rectangular area through the coordinate points (80°, 32 N·m), (90°, 32 N·m), (80°, 38 N·m), (90°, 38 N·m). According to formula (14) and formula (15), calculate c(A max ) and d(T max ) values.

[0269] When M = 217, since A max = 86.3°, T max = 33.35 N·m, so c(A max ) = 2, d(T max ) = 2.

[0270] S9: Detect the assembly reliability in real time.

[0271] Based on the values of a(A0), b(kS j ), c(A max ) and d(T max ), calculate the value of F.

[0272] When M = 217, a(A 42 ) = 1, b(kS 14 ) = 1, c(A max ) = 2, d(T max ) = 2, so the value of F is 6. Since T1 = 32 N·m < T max = 33.35 N·m < T1 = 32 N·m, A1 = 80° < A max= 86.3° < A2 = 90°, which meets the condition of Case 9. Therefore, the current state is tightened in place, and the display 2 outputs "Current state: c = 2, d = 2, both the angle and torque reach the set process parameter range, meeting the tightening requirements. Please stop tightening."

[0273] Since the current real-time detection result meets the requirements, the tightening operation is stopped, and this embodiment ends.

Claims

1. An online detection method for pipeline machine external assembly process, characterized in that: The steps include: Step S1: construct a tightening control model and initialize model parameters; The step S1 constructs an off-machine digital assembly tightening control model as shown in formula (1), F=a(A0)+b(kS j )+c(A max )+d(T max ) (1) Where F represents the final tightening effect parameter value, a(A0) represents the initial assembly specification value function, and b(kS j ) represents the slope stability coefficient kS j The value function, c(A max ) represents the maximum tightening angle A max The value function, d(T max ) represents the maximum tightening torque T max Value function; Step S2: adjusting the catheter and the joint to an initial state and applying a tightening torque; Step S3: reading the tightening process information in real time and drawing a tightening curve line graph; Step S4: Real-time determination of initial assembly standardization; Step S5: real-time fitting of the linear segment slope k j ; Step S6: judging the standardization of the assembly process in real time; Step S7: Real-time detection of the maximum tightening torque T max Maximum tightening angle A max ; Step S8: Calculate assembly results in real time; Step S9: Real-time detection of assembly reliability.

2. The method for online detection of pipeline machine assembly process according to claim 1, characterized in that: The off-machine digital assembly tightening control model includes 4 control parameters and 8 boundary parameters. The 4 control parameters are calculated from the data collected during the assembly process as input, and the 8 boundary parameters are specified in advance by the process personnel; the 4 control parameters are the fitting angle A0, the slope stability coefficient kS j , maximum tightening angle A max and the maximum tightening torque T max ; The eight boundary parameters are the fitting torque T0, the lower limit of the initial assembly specification angle range A 0min , the upper limit of the initial assembly specification angle range A 0max , slope deviation threshold KL, tightening angle interval lower limit A1, tightening angle interval upper limit A2, tightening torque interval lower limit T1, tightening torque interval upper limit T2.

3. The method for online detection of pipeline machine assembly process according to claim 1, characterized in that: The step S3 is specifically as follows: continuously applying a tightening torque to rotate the outer nut, and transmitting the applied tightening torque information T at a fixed transmission frequency f. i ,i=1,2 3,…,m, tightening angle information A i ,i=1,2 3,…,m, real-time transmission, constructed as angle matrix A and moment matrix T, where m is the number of received time series data points, and the elements of angle matrix A and moment matrix T correspond one to one; in: The received information is decoded and converted, a line graph is drawn with A as the horizontal coordinate and T as the vertical coordinate, and the tightening curve line graph is displayed in real time.

4. The method for online detection of pipeline machine assembly process according to claim 3 is characterized in that: The S4 is specifically as follows: given a reference initial moment T0, construct a fitting angle value function e(T s ), real-time comparison of the last element T of the moment matrix T s The size of the reference initial torque T0; fitting angle value function e(T m ) value, when T m When it is equal to or greater than T0, that is, T m-1 <T0 and T m ≥T0, the catheter reaches the fitting point, at this time T s The value of is the fitting moment, the last element of the angle matrix A is A s That is the fitting angle A0, 5. The method for online detection of pipeline machine external assembly process according to claim 4 is characterized in that: Construct the initial assembly specification value function a(A0): Determine whether A0 is in the interval [A 0min ,A 0max ], if A0<A 0min , then a(A0)=0. At this time, the fitting angle is too small, indicating that the catheter was not completely loosened before formal assembly and was not adjusted to the initial state, which does not meet the initial assembly specifications. It is necessary to loosen the nut and reassemble it; if A0>A 0max , then a(A0)=0. At this time, the fitting angle is too large, indicating that the catheter has initial assembly stress and does not meet the initial assembly specifications. In this case, return to step S2, loosen the nut, adjust the catheter and the connector to the initial state, apply tightening torque and reassemble. If A0 is in the interval [A 0min ,A 0max ], then a(A0)=1, which meets the initial assembly specifications.

6. The method for online detection of pipeline machine assembly process according to claim 5, characterized in that: The step S5 is specifically as follows: Continue to apply tightening torque to rotate the outer nut; the tightening curve exceeds point (A s , T s ) is a linear segment, and the identified fitting angle A s and the fitting torque T s As the starting point of a linear segment; Continue to collect tightening torque information in real time m and tightening angle information A m , mark the last element of the angle matrix A and the moment matrix T after entering the linear segment with the subscript M, M ≥ s + 1, then the last element of the angle matrix A is A M , the last element of the moment matrix T is T M ; According to formula (6), the average value of the angle in the linear interval is calculated According to formula (7), the average value of the moment in the linear interval is calculated Let j = i-s + 1, and fit the slope k of the linear segment in real time according to formula (8) j : Among them A i (i=s+1,s+2,…,M) is the element value corresponding to the subscript of the angle matrix T, where T i (i=s+1,s+2,…,M) is the element value corresponding to the subscript of the moment matrix T.

7. The method for online detection of pipeline machine assembly process according to claim 6, characterized in that: The step S6 is specifically as follows: The slope stability coefficient kS is calculated in real time by formula (9) j : in Define the slope stability factor kS j The value function b(kS j ): Set the slope deviation threshold KL. If the current kS j >KL, then b(kS j )=0, it is considered that the slope of the curve has shifted significantly, and there is a problem with the standardization of the assembly process. In this case, return to step S2, loosen the nut, adjust the catheter and the connector to the initial state, apply the tightening torque and re-assemble; if the current kS j ≤KL, then b(kS j )=1, it is considered that the slope is in a stable range and the standardization of the assembly process is good.

8. The method for online detection of pipeline machine assembly process according to claim 7, characterized in that: Step S7 is specifically as follows: Continue to apply tightening torque to rotate the outer nut. The subscript of the last element of the angle matrix A and the torque matrix T after entering the linear segment is marked as M, where M≥s+1. The maximum tightening angle A max and the maximum tightening torque T max The calculation formulas of are shown in formula (12) and formula (13) respectively; A max =max (A1,A2,…,A s ,…,A M ) (12)T max =max (T1,T2,…,T s ,…,T M ) (13)。 9. The method for online detection of pipeline machine assembly process according to claim 8, characterized in that: The step S8 is specifically as follows: Construct a plane area with angle A as the horizontal coordinate and moment T as the vertical coordinate, set the angle valid interval to [A1,A2], and set the moment valid interval to [T1,T2]; construct a boundary rectangular area RectValid through the coordinate points (A1,T1), (A2,T1), (A1,T2), (A2,T2).

10. The method for online detection of pipeline machine external assembly process according to claim 9, characterized in that: Construct the maximum tightening angle value function c(A max ) as shown in formula (14); When A max When <A1, c(A max )=0; when A max >A2, c(A max )=1; when A1≤A max When ≤A2, c(A max )=2; Construct the maximum tightening torque value function c(A max ), as shown in formula (15): When T max <T1, d(T max )=0; when T max >T2, d(T max )=1; when T1≤T max ≤T2, d(T max )=2.

11. The method for online detection of pipeline machine assembly process according to claim 10, characterized in that: The step S9 is specifically as follows: The tightening control model constructed is calculated by formula (1). The constructed boundary rectangular area RectValid divides the plane area into 9 parts, corresponding to 9 possible tightening situations.

12. The method for online detection of pipeline machine assembly process according to claim 11, characterized in that: Case 1: c(A max )=0,d(T max )=0, we can calculate F=2; in this case A max <A1,T max <T1, it is considered that the situation has not yet reached the final tightening state. In this case, the system automatically jumps to step S5 to continue to detect the tightening process in real time.

13. The method for online detection of pipeline machine assembly process according to claim 11, characterized in that: Case 2: c(A max )=1,d(T max )=0, we can calculate F=3; in this case A max >A2,T max <T1, therefore it is considered that this situation does not meet the tightening requirements. In this case, it is necessary to return to step S2, adjust the catheter and the connector to the initial state and apply the tightening torque.

14. The method for online detection of pipeline machine assembly process according to claim 11, characterized in that: Case 3: c(A max )=0,d(T max )=1, we can calculate F=3; in this case A max <A1,T max >T2, therefore, it is considered that this situation does not meet the tightening requirements. In this case, it is necessary to return to step S2, adjust the catheter and the connector to the initial state and apply the tightening torque.

15. The method for online detection of pipeline machine assembly process according to claim 11, characterized in that: Case 4: c(A max )=1,d(T max )=1, we can calculate F=4; in this case A max >A2,T max >T2, therefore, it is considered that this situation does not meet the tightening requirements. In this case, it is necessary to return to step S2, adjust the catheter and the connector to the initial state and apply the tightening torque.

16. The method for online detection of pipeline machine assembly process according to claim 11, characterized in that: Case 5: c(A max )=0,d(T max )=2, we can calculate F=4; in this case A max <A1,T1≤T max ≤T2, it is considered that the situation has not yet reached the final tightening state. In this case, the system automatically jumps to step S5 to continue to detect the tightening process in real time.

17. The method for online detection of pipeline machine assembly process according to claim 11, characterized in that: Case 6: c(A max )=2,d(T max )=0, we can calculate F=4; in this case A1≤A max ≤A2, T max <T1 angle reaches the set process parameter range, so it is considered that the situation has not yet reached the final tightening state. In this case, the system automatically jumps to step S5 to continue real-time detection of the tightening process.

18. The method for online detection of pipeline machine assembly process according to claim 11, characterized in that: Case 7: c(A max )=1,d(T max )=2, we can calculate F=5; in this case A max >A2,T1≤T max ≤T2, the torque reaches the set process parameter range, so it is considered that this situation does not meet the tightening requirements. In this case, it is necessary to return to step S2, adjust the catheter and the connector to the initial state and apply the tightening torque.

19. The method for online detection of pipeline machine assembly process according to claim 11, characterized in that: Case 8: c(A max )=2,d(T max )=1, we can calculate F=5; in this case A1≤A max ≤A2, T max >T2 angle reaches the set process parameter range, so it is considered that this situation does not meet the tightening requirements. In this case, it is necessary to return to step S2, adjust the catheter and the connector to the initial state and apply the tightening torque.

20. The method for online detection of pipeline machine assembly process according to claim 11, characterized in that: Case 9: c(A max )=2,d(T max )=2, we can calculate F=6; in this case A1≤A max ≤A2,T1≤T max ≤T2, so it is considered that the situation meets the tightening requirements. In this case, the tightening result has met the requirements and the tightening operation is ended. Since the current real-time detection result meets the requirements, the tightening operation is stopped.

21. An online detection system for pipeline machine assembly process, characterized in that: It comprises a controller (1), a display (2), a movable vehicle body (3), an assembly desktop (4) and a digital assembly tool (5); The controller 1 is used to execute an online detection method for an external assembly process of a pipeline machine according to any one of claims 1 to 20, receive assembly process information transmitted by a digital assembly tool (5), and transmit the received assembly process information to a display (2); The display (2) is used to display assembly process data and test results in real time; The movable vehicle body (3) is used to place the controller (1), the display (2) and the assembly desktop (4); The assembly table (4) is used to implement off-machine auxiliary assembly of the catheter and the connector; The digital assembly tool (5) is used to apply a tightening torque to the outer sleeve nut.

22. The online detection system for pipeline off-machine assembly process according to claim 21, characterized in that: The assembly desktop (4) comprises a fixed support (4-1), a guide rail (4-2), a slider (4-3), a posture adjustment support mechanism (4-4) and a desktop (4-5); the desktop (4-5) is installed with a fixed support (4-1) and a guide rail (4-2), the guide rail (4-2) is installed with a slider (4-3), and the slider (4-3) is installed with a posture adjustment support mechanism (4-4); The fixed support (4-1) is used to fix the pipe joint; The guide rail (4-2) is used to support the sliding block (4-3); The sliding block (4-3) is used to support the posture adjustment support mechanism; The posture adjustment support mechanism (4-4) supports the catheter to be assembled by adjusting its own posture; A threaded connection hole is reserved on the table top (4-5).

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