Gate valve element positioning and assembling device and method based on automation

Abstract

The invention discloses an automation-based gate valve element positioning and assembling device and method, and belongs to the technical field of automatic mechanical assembling. The automation-based gate valve element positioning and assembling device comprises an assembling base, a gantry movement mechanism, a Z-axis assembling head, a valve element grabbing hand, a process sensing system and a controller; the gantry movement mechanism is arranged on the assembling base and used for conducting two-dimensional movement in the horizontal plane. The Z-axis assembling head is installed on the gantry movement mechanism and comprises a linear driving part used for achieving vertical linear movement and a rotary driving part connected to the lower end of the linear driving part in series and used for achieving rotary movement. According to the valve core grabbing device, the strict requirement for the precision of a valve body positioning clamp is lowered, and the adaptability and robustness of the whole device to tool errors are improved.

Description

Technical Field

[0001] This invention relates to the field of automated mechanical assembly, specifically to an automated gate valve core positioning and assembly device and method. Background Technology

[0002] Traditional automated assembly of gate valves heavily relies on high-precision mechanical positioning and rigid preset programs. This method has an extremely low tolerance for deformation errors in parts with manufacturing tolerances, such as casting burrs. During high-speed assembly, abnormalities such as jamming and deflection can easily cause scratches on the valve core sealing surface or equipment downtime, making it impossible to balance assembly efficiency and quality. When switching production lines to different product specifications, the high cost of hardware modification and debugging time also limit its flexibility.

[0003] The technical challenge lies in resolving the conflict between high-speed assembly efficiency and the success rate of assembling 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 process state characteristics during assembly, from normal contact friction to abnormal jamming and scratching, using only low-cost sensor data such as motor current / driver torque, ordinary visual images, and contact forces, and to make dynamic responses.

[0004] Therefore, the core technical direction of this invention is to research a gate valve flexible assembly control method based on process data. This method aims to extract and analyze the temporal characteristics of multi-source information such as force, displacement, and 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, it achieves early prediction and adaptive online adjustment of assembly anomalies, such as flexible introduction and attitude correction, thereby achieving the goal of high-efficiency, high-reliability, and high-flexibility automated assembly on a low-cost hardware platform.

[0005] The information disclosed in the background section above is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide an automated gate valve core positioning and assembly device and method to solve the problems mentioned in the background art.

[0007] The technical solution of the present invention is an automated gate valve core positioning and assembly device, comprising an assembly base, a gantry motion mechanism, a Z-axis assembly head, a valve core gripper, a process sensing system, and a controller; The gantry motion mechanism is mounted on the assembly base and is used for two-dimensional motion in the horizontal plane; The Z-axis assembly head is mounted on the gantry motion mechanism, and includes a linear drive unit for realizing vertical linear motion, and a rotary drive unit connected in series at the lower end of the linear drive unit for realizing rotary motion. The valve core gripper is connected to the output end of the rotary drive unit; The process sensing system includes a multi-dimensional force sensor installed between the rotary drive unit and the valve core gripper, and a displacement sensor associated with the linear drive unit. The controller is electrically connected to the gantry motion mechanism, the Z-axis assembly head, and the process sensing system.

[0008] Preferably, the gantry motion mechanism includes a gantry frame fixed to the assembly base, and a motion component that can move along the gantry frame in a first direction and a second direction, wherein the Z-axis assembly head is mounted on the motion component.

[0009] Preferably, the process sensing system further includes a fixed industrial camera, which is mounted on the gantry motion mechanism and its field of view covers a valve body positioning station located on the assembly base.

[0010] Preferably, the valve core gripper is a pneumatic gripper with a pressure sensor on its gripper fingers. The pressure sensor is used to sense the pressure change when the valve core comes into lateral contact with the valve body cavity wall.

[0011] An automated gate valve spool positioning and assembly method includes: Model establishment steps: Based on the standard assembly samples collected during the teaching phase, including synchronous displacement sequences and multidimensional force sequences, the controller establishes a standard force-displacement model, which defines a standard force value range for each displacement point in the displacement sequence. Real-time monitoring steps: During the automatic assembly stage, the controller collects real-time force-displacement data consisting of the real-time displacement and real-time force value of the current 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 judgment is generated. Flexible adjustment step: In response to the abnormal state determination, the controller collects auxiliary state data including horizontal force and torque and classifies the abnormality. Then, based on the classification result, it executes a preset flexible adjustment strategy to drive the gantry motion mechanism or the Z-axis assembly head to perform motion compensation.

[0012] Preferably, the model building step further includes: performing statistical processing on the multidimensional force sequence of multiple 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.

[0013] Preferably, before the comparison, the real-time monitoring step further includes: 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.

[0014] Preferably, the flexible adjustment step further includes: when the abnormal state is classified as tilting 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.

[0015] Preferably, the flexible adjustment step further includes: when the abnormal state is classified as rotational jamming, the flexible adjustment strategy is to control the rotation drive of the Z-axis assembly head to perform a preset reciprocating rotational oscillation action.

[0016] This invention provides an automated gate valve core positioning and assembly device and method, which, compared with the prior art, has the following improvements and advantages: 1. Because this device is equipped with a process sensing system consisting of multi-dimensional force sensors and displacement sensors, the controller can construct force-displacement curves in real time and compare them with standard models, thereby accurately identifying abnormalities such as tilting, scraping, or rotational jamming during the assembly process. Furthermore, the controller can immediately trigger targeted flexible adjustment strategies for motion compensation, avoiding part damage or downtime caused by rigid assembly. In addition, because the process sensing system is also equipped with a fixed industrial camera, it can perform visual pre-positioning of the valve body before assembly, actively compensating for initial deviations caused by inaccurate material positions. These designs work together to significantly improve the device's adaptability and robustness to part tolerances and tooling errors without relying on high-precision positioning fixtures. 2. The process perception system can not only detect the occurrence of abnormalities, but also classify the causes of abnormalities through auxiliary data such as horizontal force and torque provided by multi-dimensional force sensors. For example, it can clearly distinguish between tilting scraping and rotational jamming, and execute targeted translation compensation or rotational swing strategies respectively, realizing refined and intelligent processing of assembly problems. 3. This scheme does not use a fixed force threshold, but instead establishes a standard model including an average curve and a dynamic tolerance band through statistical processing of multiple successful assembly samples. This method scientifically defines the allowable force fluctuation range at different assembly depths, making anomaly detection more reliable. Simultaneously, the introduction of a dynamic drift compensation curve allows the monitoring benchmark to self-adjust to adapt to the systematic drift generated by long-term equipment operation, ensuring long-term monitoring accuracy. 4. A pressure sensor is added to the gripper finger of the valve core gripper, providing an auxiliary dimension for force perception; when the valve core makes lateral contact with the cavity wall, the pressure change on the gripper finger can be monitored by the controller, which provides richer evidence for judging specific abnormal states such as tilting and scraping, and improves the accuracy of abnormal classification. Attached Figure Description

[0017] The present invention will be further explained below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the overall structure of the device; Figure 2 This is a structural schematic diagram of the assembly base; Figure 3 This is a structural schematic diagram of the gantry frame; Figure 4 This is a schematic diagram of the Z-axis assembly head; Figure 5 This is a schematic diagram of the method flow of the present invention; In the diagram: 1. Valve body positioning station; 2. Assembly base; 3. Gantry frame; 4. Y-axis guide rail; 5. X-axis crossbeam; 6. Z-axis assembly head; 7. Ball screw module; 8. Servo rotary motor; 9. Valve core gripper; 10. Multi-dimensional force sensor; 11. Miniature pressure sensor; 12. Fixed industrial camera; 13. Valve body positioning fixture. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. Example 1

[0019] Please see Figure 1-4 The present invention provides an automated gate valve core positioning and assembly device, including an assembly base 2, a gantry motion mechanism, a Z-axis assembly head 6, a valve core gripper 9, a process sensing system and a controller; The gantry motion mechanism is mounted on the assembly base 2 and is used for two-dimensional motion in the horizontal plane; The Z-axis assembly head 6 is mounted on the gantry motion mechanism, which includes a linear drive unit for realizing vertical linear motion and a rotary drive unit connected in series at the lower end of the linear drive unit for realizing rotary motion. The valve core gripper 9 is connected to the output end of the rotary drive unit; The process sensing system includes a multi-dimensional force sensor 10 installed between the rotary drive unit and the valve core gripper 9, and a displacement sensor associated with the linear drive unit. The controller is electrically connected to the gantry motion mechanism, the Z-axis assembly head 6, and the process sensing system.

[0020] The linear drive unit for achieving vertical linear motion is a ball screw module 7, and the rotary drive unit for achieving rotary motion is a servo rotary motor 8. This combination of structures ensures that the Z-axis assembly head 6 can achieve precise lifting and rotating combined motion. In this embodiment, an automated gate valve core positioning and assembly device is provided to address the shortcomings of traditional rigid assembly methods. This device uses a process sensing system to acquire real-time status information of the valve core during assembly. The multi-dimensional force sensor 10 can be an ATIOmega160 model, and the displacement sensor is an encoder integrated into the Z-axis servo motor, such as the 23-bit encoder built into the Panasonic MINASA6 series servo motor. The controller can be a Siemens SIMATIC S7-1500 model, used to receive the force and displacement data collected by the process sensing system and to control the movement of the gantry motion mechanism and the Z-axis assembly head 6 in real time based on this data. This design allows the device to move beyond simply relying on a preset fixed trajectory and dynamically adjust based on actual force feedback, thereby improving the assembly success rate of non-ideal parts without relying on expensive, high-precision hardware.

[0021] The gantry motion mechanism includes a gantry frame 3 fixed on the assembly base 2, and a motion component that can move along the gantry frame 3 in a first direction and a second direction. The Z-axis assembly head 6 is mounted on the motion component.

[0022] 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 movement by setting a gantry frame 3 spanning across the assembly base 2. The motion component, such as a slider assembly that can slide on the X-axis beam 5 and the Y-axis guide rail 4, is driven by an independent servo motor in conjunction with a ball screw. The purpose of this structure is to achieve high-rigidity two-dimensional planar motion, ensuring that the Z-axis assembly head 6 can be accurately transported to a predetermined position above the valve body, providing an accurate starting point for subsequent vertical insertion actions. By mounting the Z-axis assembly head 6 on the motion component, the horizontal two-dimensional motion and the vertical one-dimensional motion are decoupled, laying the structural foundation for executing independent horizontal compensation motion in subsequent flexible adjustment strategies.

[0023] The process sensing system also includes a fixed industrial camera 12, which is mounted on the gantry motion mechanism and its field of view covers a valve body positioning station 1 located on the assembly base 2.

[0024] In this embodiment, the capabilities of the process sensing system are expanded. A fixed industrial camera 12, such as a Keyence IV-G500MA vision sensor, is added and fixedly mounted on the crossbeam of the gantry frame 3, ensuring its field of view stably covers the valve body positioning station 1 below. The purpose of this design is to perform visual positioning of the valve body placed at the station before the valve core assembly begins. The controller processes the image captured by the industrial camera to identify the center coordinates of the valve cavity. Subsequently, the controller drives the gantry motion mechanism to move the valve core gripper 9 carrying the valve core directly above these coordinates. This step effectively compensates for minor deviations in the valve body's incoming position, reducing the accuracy requirements of the valve body positioning fixture 13, thereby improving the overall device's adaptability to tooling errors while maintaining positioning accuracy.

[0025] The valve core gripper 9 is a pneumatic gripper with a pressure sensor on its gripper fingers. The pressure sensor is used to sense the pressure change when the valve core comes into lateral contact with the valve body cavity wall.

[0026] In this embodiment, the structure of the valve core gripper 9 is specified. The valve core gripper 9 adopts the form of a pneumatic gripper to reliably hold the valve core. The key feature is that a miniature pressure sensor 11 is additionally set at the base of the gripper's fingers. The purpose of this design is to provide an auxiliary force perception dimension. When the valve core tilts during downward insertion, and its edge makes lateral contact or scrapes against the valve body cavity wall, this contact force is transmitted to the gripper, causing an abnormal change in the pressure sensor reading on the gripper's fingers. By monitoring this pressure change, the controller can more accurately determine the specific abnormal state of tilting and scraping, providing richer judgment basis for subsequent execution of targeted flexible adjustment strategies, thereby improving the accuracy of abnormal classification. Example 2

[0027] See Figure 5 An automated gate valve spool positioning and assembly method includes: Model building steps: Based on the standard assembly samples collected during the teaching phase, including synchronous displacement sequences and multidimensional force sequences, the controller establishes a standard force-displacement model, which defines a standard force value range for each displacement point in the displacement sequence. Real-time monitoring steps: During the automatic assembly stage, the controller collects real-time force-displacement data consisting of the real-time displacement and real-time force value of the current 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 judgment is generated. Flexible adjustment steps: In response to the abnormal state determination, the controller collects auxiliary state data including horizontal force and torque and classifies the abnormality. Then, based on the classification results, it executes the preset flexible adjustment strategy to drive the gantry motion mechanism or Z-axis assembly head 6 to perform motion compensation.

[0028] In this embodiment, the core of the control method is to transform the assembly process from an open execution process into a data feedback-based adjustment process. In the model building step, by having the device perform several successful assembly actions using standard parts, the controller can learn and record the complete force-displacement curve of the next ideal assembly process, forming a standard force-displacement model. The core advantage of this standard force-displacement model is that it is not a simple, fixed upper limit threshold of force, but can accurately depict every depth, displacement point, and normal contact and friction force during the valve core insertion process. This is like drawing a precise force map for the entire assembly process, enabling the system to intelligently distinguish which are the resistances that will inevitably occur during normal assembly and which are the actual tilting, scraping, or jamming abnormalities, thus making more timely and accurate judgments and adjustments. After entering the real-time monitoring step, the controller compares the real-time force-displacement data with the pre-established model during each automatic assembly. The purpose is to detect deviations from the ideal state in a timely manner. Once the real-time force value exceeds the standard force value range defined by the model, the flexible adjustment step is triggered. The controller will combine other dimension data from the multi-dimensional force sensor 10 to analyze the cause of the anomaly and execute the corresponding compensating motion. 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 the protection of parts.

[0029] The model building steps further include: performing statistical processing on the multidimensional force sequences of multiple 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, which is the standard force value range.

[0030] In this embodiment, the specific implementation of the model building steps is described. To make the established standard force-displacement model more robust, the controller performs statistical processing on the standard assembly samples collected from multiple teaching demonstrations. The controller aligns all sample data according to displacement, and at each displacement sampling point, calculates the average and standard deviation of the force value of all samples at that point. Connecting all the average points forms an average force-displacement curve, which represents the most typical successful assembly process. At the same time, by superimposing and subtracting a preset multiple of the standard deviation, such as three times the standard deviation, on 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 subsequent anomaly judgments more reliable and accurate.

[0031] Before the comparison, the real-time monitoring step further includes: generating a dynamic drift compensation curve based on a preset number of recent successful assembly data, and applying the dynamic drift compensation curve to a standard force-displacement model to generate a compensated model for real-time comparison.

[0032] In this embodiment, the adaptability of the real-time monitoring step is enhanced. Considering that after prolonged operation, the equipment may experience slight systematic drift due to factors such as temperature changes and mechanical wear, leading to changes in the force sensor baseline, the controller performs a dynamic compensation process before real-time comparison to address this issue. The controller caches recent force-displacement data from, for example, the last 20 successful assembly attempts and calculates a new average curve based on this 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. This difference curve 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. Using this compensated model for real-time comparison aims to allow the monitoring benchmark to dynamically adapt to the current state of the equipment, avoiding false alarms caused by system drift and improving the long-term accuracy of monitoring.

[0033] The flexible adjustment step further includes: when the abnormal state is classified as tilting 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.

[0034] In this embodiment, a flexible adjustment strategy for the specific anomaly of tilting scraping is described in detail. When the controller determines that an anomaly has occurred during the real-time monitoring step, it immediately analyzes the auxiliary state data collected by the multi-dimensional force sensor 10. If the data shows that the vertical force exceeds the tolerance zone, and at the same time a significant horizontal force is detected in a certain horizontal direction, such as the X direction, the controller will classify this anomaly as tilting scraping. At this time, the flexible adjustment strategy is executed: the controller first instructs the Z-axis assembly head 6 to lift slightly to release stress, drives the gantry motion mechanism to perform a small translational compensation movement in the X direction opposite to the direction of the detected horizontal force. The purpose of this is to actively correct the tilting posture of the valve core and make it realign with the center line of the valve cavity. Then, it attempts to continue to assemble downwards, thereby effectively solving the scraping problem caused by incorrect posture.

[0035] The flexible adjustment step further includes: when the abnormal state is classified as rotational jamming, the flexible adjustment strategy is to control the rotation drive of the Z-axis assembly head 6 to perform a preset reciprocating rotational oscillation action.

[0036] In this embodiment, a flexible adjustment strategy for the anomaly of rotational jamming is described in detail. When the controller determines that an anomaly has occurred and finds that the vertical force far exceeds the threshold from the auxiliary status data, and at the same time detects a significant rotational torque, the anomaly is classified as rotational jamming. This is usually caused by burrs or local deformation of the parts. To deal with this situation, a flexible adjustment strategy is activated: the controller stops the downward movement of the Z-axis and then instructs the rotation drive at the lower end of the Z-axis assembly head 6 to perform a small-range reciprocating rotational oscillation at a preset angle. The purpose of this action is to use slight rotational disturbance to help the corners of the valve core overcome the jamming point, similar to gently turning to find the right position when encountering resistance during manual assembly. While performing the oscillation action, the controller continuously monitors the torque value. Once the torque returns to the normal range, the oscillation stops and the downward assembly continues, thereby overcoming the jamming caused by hard contact in a flexible manner.

[0037] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. An automated gate valve core positioning and assembly device, characterized in that, Includes assembly base (2), gantry motion mechanism, Z-axis assembly head (6), valve core gripper (9), process sensing system and controller; The gantry motion mechanism is mounted on the assembly base (2) and is used to perform two-dimensional motion in the horizontal plane; The Z-axis assembly head (6) is mounted on the gantry motion mechanism, and includes a linear drive unit for realizing vertical linear motion and a rotary drive unit connected in series at the lower end of the linear drive unit for realizing rotary motion. The valve core gripper (9) is connected to the output end of the rotary drive unit; The process sensing system includes a multi-dimensional force sensor (10) installed between the rotary drive unit and the valve core gripper (9), and a displacement sensor associated with the linear drive unit. The controller is electrically connected to the gantry motion mechanism, the Z-axis assembly head (6), and the process sensing system.

2. The gate valve core positioning and assembly device based on automation according to claim 1, characterized in that, The gantry motion mechanism includes a gantry frame (3) fixed on the assembly base (2) and a motion component that can move along the gantry frame (3) in a first direction and a second direction. The Z-axis assembly head (6) is mounted on the motion component.

3. The gate valve core positioning and assembly device based on automation according to claim 1, characterized in that, The process sensing system also includes a fixed industrial camera (12), which is mounted on the gantry motion mechanism and its field of view covers a valve body positioning station (1) located on the assembly base (2).

4. The gate valve core positioning and assembly device based on automation according to claim 1, characterized in that, The valve core gripper (9) is a pneumatic gripper with a pressure sensor on its gripper fingers. The pressure sensor is used to sense the pressure change when the valve core comes into lateral contact with the valve body cavity wall.

5. A gate valve spool positioning and assembly method based on automation, characterized in that, An automated gate valve core positioning and assembly device according to any one of claims 1 to 4, comprising: Model establishment steps: Based on the standard assembly samples collected during the teaching phase, including synchronous displacement sequences and multidimensional force sequences, the controller establishes a standard force-displacement model, which defines a standard force value range for each displacement point in the displacement sequence. Real-time monitoring steps: During the automatic assembly stage, the controller collects real-time force-displacement data consisting of the real-time displacement and real-time force value of the current 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 judgment is generated. Flexible adjustment steps: In response to the abnormal state determination, the controller collects auxiliary state data including horizontal force and torque and classifies the abnormality. Then, based on the classification result, it executes a preset flexible adjustment strategy to drive the gantry motion mechanism or the Z-axis assembly head (6) to perform motion compensation.

6. The gate valve core positioning and assembly method based on automation according to claim 5, characterized in that, The model building step further includes: performing statistical processing on the multidimensional force sequence of multiple 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.

7. The gate valve core positioning and assembly method based on automation according to claim 5, characterized in that, Before the comparison, the real-time monitoring step further includes: 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.

8. The gate valve core positioning and assembly method based on automation according to claim 5, characterized in that, The flexible adjustment step further includes: when the abnormal state is classified as tilting 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.

9. The gate valve core positioning and assembly method based on automation according to claim 5, characterized in that, The flexible adjustment step further includes: when the abnormal state is classified as rotational jamming, the flexible adjustment strategy is to control the rotation drive of the Z-axis assembly head (6) to perform a preset reciprocating rotational swing action.

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