An automated gate valve trim positioning assembly method

Abstract

The application discloses an automatic gate valve core positioning and assembling method, and belongs to the technical field of automatic mechanical assembling. The method comprises a device configured to execute the gate valve core positioning and assembling method, wherein the device comprises an assembling base, a gantry motion mechanism, a Z-axis assembling head, a valve core grabbing hand, a process sensing system and a controller. The gantry motion mechanism is arranged on the assembling base and is used for two-dimensional motion in a horizontal plane. The Z-axis assembling head is installed on the gantry motion mechanism and comprises a linear driving part used for realizing vertical linear motion and a rotary driving part connected to the lower end of the linear driving part and used for realizing rotary motion. The valve core grabbing hand is connected to the output end of the rotary driving part. The application reduces the strict requirement for the precision of a valve body positioning clamp, and improves the adaptability and robustness of the whole device to tooling errors.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automatic mechanical assembly, in particular to a gate valve spool positioning and assembling method based on automation. BACKGROUND

[0002] Traditional gate valve automatic assembly relies heavily on high-precision mechanical positioning and rigid preset programs. This mode has very low fault tolerance for parts with manufacturing tolerances, such as casting burrs and deformation. In high-speed assembly, abnormal conditions such as jamming and deflection can easily cause valve core sealing surface scratches or equipment downtime, and it is difficult to balance assembly efficiency and quality. When the production line switches to different specifications, the high cost of hardware modification and debugging time also limit its flexibility.

[0003] The technical contradiction lies in how to solve the conflict between high-speed assembly efficiency and assembly success rate for non-ideal parts without relying on expensive high-precision hardware. The core challenge is to develop a control method that enables the system to accurately identify and classify the process state characteristics from normal contact friction to abnormal jamming and scratching during assembly using low-cost sensor data such as motor current / driver torque, ordinary vision images, and contact force, and make dynamic responses in real time.

[0004] Therefore, the core technology direction of the present application is to study a gate valve flexible assembly control method based on process data driving. This method aims to extract and analyze the time sequence characteristics of multi-source information such as force-displacement-vision online through machine learning and other means, and establish a digital twin model of the standard assembly process. By comparing the real-time state with the model, early prediction and adaptive online adjustment of assembly abnormalities are achieved, such as flexible introduction and posture correction, so as to achieve the goals of high efficiency, high reliability and high flexibility of automatic assembly on a low-cost hardware platform.

[0005] The information disclosed in the above BACKGROUND section is only used to strengthen the understanding of the background of the present disclosure, and therefore it can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0006] The purpose of the present application is to provide a gate valve spool positioning and assembling method based on automation to solve the problems raised in the above BACKGROUND.

[0007] The technical solution of the present application is a gate valve spool positioning and assembling method based on automation, which comprises a device configured to perform the gate valve spool positioning and assembling method, the device comprising an assembly base, a gantry motion mechanism, a Z-axis assembly head, a valve core grabbing hand, a process sensing system and a controller.

[0008] The gantry motion mechanism is arranged on the assembly base and is used for two-dimensional motion in the horizontal plane.

[0009] The Z-axis assembly head is mounted on the gantry motion mechanism, and includes a linear driving part for realizing vertical linear motion, and a rotary driving part connected in series at the lower end of the linear driving part and used for realizing rotary motion;

[0010] The valve core grabbing hand is connected to the output end of the rotary driving part;

[0011] The process perception system includes a multi-dimensional force sensor mounted between the rotary driving part and the valve core grabbing hand, and a displacement sensor associated with the linear driving part;

[0012] The controller is electrically connected with the gantry motion mechanism, the Z-axis assembly head, and the process perception system.

[0013] Preferably, the gantry motion mechanism includes a gantry frame fixed on the assembly base, and a motion assembly movable along the gantry frame in a first direction and a second direction, and the Z-axis assembly head is mounted on the motion assembly.

[0014] Preferably, the process perception system further includes a fixed industrial camera, which is mounted on the gantry motion mechanism and has a camera field of view covering a valve body positioning station provided on the assembly base.

[0015] Preferably, the valve core grabbing hand is a pneumatic gripper, and a pressure sensor is provided on the gripper finger of the pneumatic gripper, which is used to perceive the pressure change when the valve core comes into lateral contact with the cavity wall of the valve body.

[0016] The gate valve core positioning and assembling method includes the following steps:

[0017] The model establishing step: the controller establishes a standard force-displacement model based on the standard assembly samples collected in the teaching stage, including the synchronized displacement sequence and multi-dimensional force sequence, and the model defines a standard force value range for each displacement point in the displacement sequence;

[0018] The real-time monitoring step: the controller collects real-time force-displacement data composed of real-time displacement and real-time force value during automatic assembly, and compares the real-time force value with the standard force value range defined by the standard force-displacement model at the corresponding real-time displacement point, and generates an abnormal state judgment if the real-time force value exceeds the standard force value range.

[0019] The flexible adjustment step: the controller collects auxiliary state data including horizontal force and moment and classifies the abnormality in response to the abnormal state judgment, and then executes a preset flexible adjustment strategy based on the classification result to drive the gantry motion mechanism or the Z-axis assembly head to perform motion compensation.

[0020] Preferably, the model establishing step further comprises: statistically processing the multi-dimensional force sequence of a plurality of standard assembly samples at each displacement point of the displacement sequence to generate an average force-displacement curve and a dynamic tolerance band around the curve, wherein the dynamic tolerance band is the standard force value range.

[0021] Preferably, the real-time monitoring step further comprises, before comparison, generating a dynamic drift compensation curve based on a preset number of recent successful assembly data, and applying the dynamic drift compensation curve to the standard force-displacement model to generate a compensated model for real-time comparison.

[0022] Preferably, the flexible adjustment step further comprises: when the abnormal state is classified as inclined scraping, the flexible adjustment strategy is to control the gantry motion mechanism to perform a small translational compensation motion opposite to the horizontal force direction detected in the auxiliary state data.

[0023] Preferably, the flexible adjustment step further comprises: when the abnormal state is classified as rotational jamming, the flexible adjustment strategy is to control the rotation drive part of the Z-axis assembly head to perform a preset reciprocating rotational swing motion.

[0024] The present application provides an automatic gate valve spool positioning and assembly method, which has the following improvements and advantages compared with the prior art.

[0025] 1. Because the device is provided with a process perception system composed of multi-dimensional force sensors and displacement sensors, the controller can construct a force-displacement curve in real time and compare it with a standard model, thereby accurately identifying abnormalities such as inclined scraping or rotational jamming during assembly; further, the controller can immediately trigger a targeted flexible adjustment strategy for motion compensation, avoiding part damage or downtime caused by hard assembly. In addition, because the process perception system is also provided with a fixed industrial camera, it can perform visual pre-positioning of the valve body before assembly, actively compensating for the initial deviation caused by inaccurate incoming position. These designs work together to significantly improve the adaptability and robustness of the device to part tolerances and tooling errors without relying on high-precision positioning fixtures.

[0026] 2. The process perception system can not only determine the occurrence of abnormalities, but also classify the causes of abnormalities through auxiliary data such as horizontal force and torque provided by the multi-dimensional force sensors; for example, it can clearly distinguish between inclined scraping and rotational jamming, and perform targeted translational compensation or rotational swing strategy respectively, achieving fine and intelligent processing of assembly problems.

[0027] 3. The scheme does not use a fixed force threshold, but through the statistical processing of multiple successful assembly samples, a standard model containing the average curve and dynamic tolerance band is established; this method scientifically defines the allowable force value fluctuation range at different assembly depths, making the abnormality judgment more reliable. At the same time, through the introduction of the dynamic drift compensation curve, the monitoring reference can be self-adjusted to adapt to the systematic drift caused by long-term operation of the equipment, ensuring the long-term accuracy of the monitoring;

[0028] 4. A pressure sensor is added to the clamping fingers of the valve core grabbing hand to provide an auxiliary dimension for force perception; when the valve core comes into lateral contact with the cavity wall, the pressure change on the clamping fingers can be monitored by the controller, which provides more abundant basis for judging specific abnormal states such as oblique scraping, and improves the accuracy of abnormal classification. BRIEF DESCRIPTION OF DRAWINGS

[0029] The application will be further explained in conjunction with the drawings and examples:

[0030] Figure 1 is the overall structure schematic diagram of the device;

[0031] Figure 2 is the structure schematic diagram of the assembly base;

[0032] Figure 3 is the structure schematic diagram of the gantry frame;

[0033] Figure 4 is the structure schematic diagram of the Z-axis assembly head;

[0034] Figure 5 is the method flow schematic diagram of the application;

[0035] In the figure: 1, valve body positioning station; 2, assembly base; 3, gantry frame; 4, Y-axis guide rail; 5, X-axis cross beam; 6, Z-axis assembly head; 7, ball screw module; 8, servo rotary motor; 9, valve core grabbing hand; 10, multi-dimensional force sensor; 11, micro pressure sensor; 12, fixed industrial camera; 13, valve body positioning clamp. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the application more clear and obvious, the application will be further described in detail below in combination with specific examples.

[0037] Example 1

[0038] Please refer to Figures 1-4 , the application provides a kind of based on automatic gate valve core positioning assembly method, including being configured for executing the gate valve core positioning assembly method Device, the device includes assembly base 2, gantry mechanism, Z-axis assembly head 6, valve core grabbing hand 9, process perception system and controller;

[0039] The gantry motion mechanism is arranged on the assembly base 2 and is used for two-dimensional motion in a horizontal plane.

[0040] The Z-axis assembly head 6 is installed on the gantry motion mechanism and includes a linear driving part used for realizing vertical linear motion and a rotary driving part connected to the lower end of the linear driving part and used for realizing rotary motion.

[0041] The valve core grabbing hand 9 is connected to the output end of the rotary driving part.

[0042] The process sensing system includes a multi-dimensional force sensor 10 installed between the rotary driving part and the valve core grabbing hand 9 and a displacement sensor associated with the linear driving part.

[0043] The controller is electrically connected to the gantry motion mechanism, the Z-axis assembly head 6 and the process sensing system.

[0044] The linear driving part used for realizing vertical linear motion is a ball screw module 7, and the rotary driving part used for realizing rotary motion is a servo rotary motor 8, and the combination of the structure ensures that the Z-axis assembly head 6 can realize precise lifting and rotary composite motion.

[0045] In the embodiment, an automatic gate valve core positioning and assembling device is used to solve the problems of the traditional rigid assembly method. The device acquires the state information of the valve core in the assembly process in real time by setting a process sensing system. The multi-dimensional force sensor 10 can be of the ATIOmega160 model, and the displacement sensor is an encoder integrated in the Z-axis servo motor, such as the 23-bit encoder of the Panasonic MINASA6 series servo motor. The controller can be of the SIMATIC S7-1500 model of Siemens, which is used to receive the force and displacement data collected by the process sensing system and to control the motion of the gantry motion mechanism and the Z-axis assembly head 6 in real time based on the data. This design makes the device no longer simply rely on the preset fixed track, but can dynamically adjust according to the actual force feedback, thereby improving the assembly success rate of non-ideal parts without relying on expensive high-precision hardware.

[0046] The gantry motion mechanism includes a gantry frame 3 fixed on the assembly base 2 and a motion assembly that can move along the gantry frame 3 in a first direction and a second direction, and the Z-axis assembly head 6 is installed on the motion assembly.

[0047] In this embodiment, the specific structure of the gantry motion mechanism is further clarified. The gantry motion mechanism provides a stable support platform for horizontal motion by setting a gantry frame 3 above the assembly base 2. The motion assembly, such as a slider combination that can slide on the X-axis beam 5 and the Y-axis guide rail 4, is driven by independent servo motors and ball screws. The purpose of this structure is to achieve high-rigidity two-dimensional plane motion, ensuring that the Z-axis assembly head 6 can be accurately transported to the predetermined position above the valve body, providing an accurate starting point for the subsequent vertical insertion action. By installing the Z-axis assembly head 6 on the motion assembly, the decoupling of horizontal two-dimensional motion and vertical one-dimensional motion is achieved, laying a structural foundation for the subsequent independent horizontal compensation motion in the flexible adjustment strategy.

[0048] The process perception system also includes a fixed industrial camera 12 installed on the gantry motion mechanism, with a camera field of view covering a valve body positioning station 1 provided on the assembly base 2.

[0049] In this embodiment, the capability of the process perception system is expanded. By adding a fixed industrial camera 12, such as a Keyence IV-G500MA vision sensor, and fixing it on the beam of the gantry frame 3, its field of view can stably cover the valve body positioning station 1 below. The purpose of this design is to perform a visual positioning of the valve body placed on the station before the valve core assembly action begins. The controller identifies the center coordinates of the valve cavity by processing the images captured by the industrial camera. Subsequently, the controller drives the gantry motion mechanism to move the valve core grabbing hand 9 carrying the valve core to directly above the coordinates. This step can effectively compensate for the slight deviation of the valve body incoming position, reducing the requirement for the precision of the valve body positioning clamp 13, thereby ensuring positioning accuracy while improving the adaptability of the entire device to tooling errors.

[0050] The valve core grabbing hand 9 is a pneumatic gripper with a pressure sensor on the fingers, which is used to sense the pressure change when the valve core comes into lateral contact with the valve body cavity wall.

[0051] In the present embodiment, the structure of the valve core gripping hand 9 is embodied, which is in the form of a pneumatic gripper to achieve reliable clamping of the valve core, and the key is that a micro pressure sensor 11 is additionally arranged at the root of the gripper finger. The purpose of this design is to provide an auxiliary force perception dimension. When the valve core is tilted during the downward insertion process, the edge of the valve core comes into contact or scraping with the wall of the valve body cavity, and the contact force is transmitted to the gripper, causing abnormal change of the pressure sensor reading on the gripper finger. The controller can more accurately judge the specific abnormal state of tilting and scraping by monitoring this pressure change, and provide more abundant judgment basis for subsequent execution of targeted flexible adjustment strategy, thereby improving the accuracy of abnormal classification.

[0052] Embodiment 2

[0053] Referring to Figure 5 The gate valve core positioning assembly method comprises the following steps:

[0054] Model establishing step: the controller establishes a standard force-displacement model based on the standard assembly sample collected in the teaching stage, including the synchronous displacement sequence and multi-dimensional force sequence, which defines a standard force value range for each displacement point in the displacement sequence;

[0055] Real-time monitoring step: the controller collects real-time force-displacement data composed of real-time displacement and real-time force value during automatic assembly, and compares the real-time force value with the standard force value range defined by the standard force-displacement model at the corresponding real-time displacement point. If the real-time force value exceeds the standard force value range, an abnormal state is determined;

[0056] Flexible adjustment step: the controller responds to the abnormal state determination, collects auxiliary state data including horizontal force and moment, and classifies the abnormality, and then executes the preset flexible adjustment strategy based on the classification result to drive the gantry motion mechanism or the Z-axis assembly head 6 to perform motion compensation.

[0057] In the present embodiment, the core of the control method is to change the assembly process from an open execution process to a regulation process based on data feedback. In the model establishing step, the controller learns and records the complete force-displacement curve of an ideal assembly process by allowing the device to perform several successful assembly actions using standard parts, forming a standard force-displacement model.

[0058] The core advantage of this standard force-displacement model is that, instead of a simple, fixed upper limit threshold of force, it can accurately depict how large the normal contact and friction force should be at each depth of the valve core insertion process; this is like drawing a precise force map for the entire assembly process, allowing the system to intelligently distinguish between which are the inevitable resistance during normal assembly and which are the real abnormality of tilting, scraping or jamming, so as to make more timely and accurate judgments and adjustments;

[0059] After entering the real-time monitoring step, the controller compares the real-time force-displacement data with the pre-established model in each automatic assembly, aiming to find deviations from the ideal state in time. Once the real-time force value exceeds the standard force value range defined by the model, the flexible adjustment step is triggered, and the controller analyzes the abnormal reason in combination with other dimension data of the multi-dimensional force sensor 10 and executes the corresponding compensation movement; this method enables the device to actively adapt to part tolerances and minor disturbances during the assembly process, significantly improving the success rate of assembly and protection of parts.

[0060] The model establishment step further includes: statistically processing the multi-dimensional force sequence of the plurality of standard assembly samples at each displacement point of the displacement sequence to generate an average force-displacement curve and a dynamic tolerance band around the curve, and the dynamic tolerance band is the standard force value range.

[0061] In this embodiment, the specific implementation of the model establishment step is described. In order to make the established standard force-displacement model more robust, the controller will statistically process the standard assembly samples collected by multiple teaching. The controller will align all sample data by displacement, calculate the average value and standard deviation of the force value at each displacement sampling point for all samples, connect all average value points to form an average force-displacement curve, which represents the most typical successful assembly process; at the same time, by adding and subtracting a preset multiple of the standard deviation, such as three times the standard deviation, from the average curve, a dynamic tolerance band is formed. This dynamic tolerance band is the standard force value range, which not only defines the ideal force value, but also scientifically defines the allowable force value fluctuation range at each assembly depth, making the subsequent abnormal judgment more reliable and accurate.

[0062] The real-time monitoring step further includes, before comparison: generating a dynamic drift compensation curve based on a preset number of recent successful assembly data, and applying the dynamic drift compensation curve to the standard force-displacement model to generate a compensated model for real-time comparison.

[0063] In this embodiment, the adaptability of the real-time monitoring step is enhanced. Considering that the device may produce slight systematic drifts after long-term operation due to factors such as temperature changes, mechanical wear, etc., causing the baseline of the force sensor to change, in order to address this problem, the controller will perform a dynamic compensation process before performing real-time comparison. The controller will cache the force-displacement data of the last successful assembly, for example, the last 20 times, and calculate a new average curve based on these data. By comparing this new average curve with the average curve in the initially established standard force-displacement model, the difference between the two is obtained, which is the dynamic drift compensation curve. The controller then applies this compensation curve to the original standard force-displacement model to generate a compensated model. The purpose of using this compensated model for real-time comparison is to enable the monitoring reference to dynamically adapt to the current state of the device, avoiding false alarms caused by system drift and improving the long-term accuracy of monitoring.

[0064] The flexible adjustment step further comprises: when the abnormal state is classified as inclined scraping, the flexible adjustment strategy is to control the gantry motion mechanism to perform a small translational compensation motion opposite to the direction of the horizontal force detected in the auxiliary state data.

[0065] In this embodiment, the flexible adjustment strategy for the specific abnormality of inclined scraping is described in detail. When the controller determines that an abnormality occurs in the real-time monitoring step, it will immediately analyze the auxiliary state data collected by the multi-dimensional force sensor 10. If the data shows that the vertical force exceeds the tolerance band, and at the same time a significant horizontal force is detected in a certain horizontal direction, for example, the X direction, the controller will classify this abnormality as inclined scraping. At this time, the flexible adjustment strategy is executed: the controller first instructs the Z-axis assembly head 6 to slightly lift to release stress, drives the gantry motion mechanism, and performs a small translational compensation motion in the X direction opposite to the direction of the detected horizontal force. The purpose of this is to actively correct the inclined posture of the valve core and make it re-align with the center line of the valve cavity, and then attempt to continue assembly downward, thereby effectively solving the scraping problem caused by the incorrect posture.

[0066] The flexible adjustment step further comprises: when the abnormal state is classified as rotational jamming, the flexible adjustment strategy is to control the rotational drive part of the Z-axis assembly head 6 to perform a preset reciprocating rotational swing action.

[0067] In this embodiment, the flexible adjustment strategy for the abnormality of rotation jamming is described in detail. When the controller determines that the abnormality occurs, and finds that the vertical force is far beyond the threshold value from the auxiliary state data, and detects a significant rotation torque at the same time, the abnormality is classified as rotation jamming, which is usually caused by burrs or local deformation of the parts, and the flexible adjustment strategy is activated to deal with this situation: the controller stops the downward movement of the Z-axis, and then instructs the rotation driving part at the lower end of the Z-axis assembly head 6 to perform a small-range reciprocating rotation swing action of a preset angle; the purpose of this action is to use slight rotation disturbance to help the corners of the valve core to pass the jamming point, which is similar to the situation that when encountering resistance during manual assembly, the valve core is slightly rotated to find the appropriate position; while performing the swing action, the controller continuously monitors the torque value, and once the torque returns to the normal range, the swing is stopped and the downward assembly is continued, so that the hard contact caused by the jamming is overcome in a flexible manner.

[0068] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application but not limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. An automated based gate valve trim positioning assembly method, characterized by, The application relates to a device configured for performing a gate valve spool positioning assembly method, the device comprising an assembly base (2), a gantry motion mechanism, a Z-axis assembly head (6), a spool grabbing hand (9), a process perception system and a controller. The gantry motion mechanism is arranged on the assembly base (2) and is used for two-dimensional motion in a horizontal plane. The Z-axis assembly head (6) is installed on the gantry motion mechanism and comprises a linear driving part used for vertical linear motion and a rotary driving part connected to the lower end of the linear driving part and used for rotary motion. The spool grabbing hand (9) is connected to the output end of the rotary driving part. The process perception system comprises a multi-dimensional force sensor (10) installed between the rotary driving part and the spool grabbing hand (9) and a displacement sensor associated with the linear driving part. The controller is electrically connected with the gantry motion mechanism, the Z-axis assembly head (6) and the process perception system. The process perception system further comprises a fixed industrial camera (12) installed on the gantry motion mechanism, and a camera visual field of the industrial camera covers a valve body positioning station (1) arranged on the assembly base (2). The spool grabbing hand (9) is a pneumatic gripper, and a pressure sensor is arranged on the gripper finger of the pneumatic gripper, and the pressure sensor is used for sensing pressure change when the spool comes into lateral contact with the cavity wall of the valve body. The gate valve spool positioning assembly method comprises the following steps. A model establishing step: the controller establishes a standard force-displacement model based on standard assembly samples collected in a teaching stage, the standard assembly samples comprising synchronous displacement sequences and multi-dimensional force sequences, and the model defines a standard force value range for each displacement point in the displacement sequences. A real-time monitoring step: the controller collects real-time force-displacement data composed of real-time displacement and real-time force value during automatic assembly, compares the real-time force value with the standard force value range defined by the standard force-displacement model at the corresponding real-time displacement point, and generates an abnormal state judgment if the real-time force value exceeds the standard force value range. A flexible adjustment step: the controller collects auxiliary state data including horizontal force and moment and classifies the abnormality in response to the abnormal state judgment, and then executes a preset flexible adjustment strategy based on the classification result to drive the gantry motion mechanism or the Z-axis assembly head (6) to perform motion compensation. The model establishing step further comprises: statistically processing the multi-dimensional force sequences of a plurality of standard assembly samples at each displacement point of the displacement sequences to generate an average force-displacement curve and a dynamic tolerance band around the curve, and the dynamic tolerance band is the standard force value range. The real-time monitoring step further comprises, before comparison: generating a dynamic drift compensation curve based on a preset number of recent successful assembly data, and applying the dynamic drift compensation curve to the standard force-displacement model to generate a compensated model used for real-time comparison. The flexible adjustment step further comprises: when the abnormal state is classified as inclined scraping, the flexible adjustment strategy is to control the gantry motion mechanism to perform a slight translation compensation motion opposite to the horizontal force direction detected in the auxiliary state data; The flexible adjustment step further comprises: when the abnormal state is classified as rotational sticking, the flexible adjustment strategy is to control the rotation driving part of the Z-axis assembly head (6) to perform a preset reciprocating rotation swing action.

2. An automated-based valve trim positioning assembly method for a gate valve as set forth in claim 1, wherein, The gantry motion mechanism comprises a gantry frame (3) fixed on the assembly base (2), and a motion assembly capable of moving along the gantry frame (3) in a first direction and a second direction, and the Z-axis assembly head (6) is installed on the motion assembly.

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