A control system based on a pipe grabbing robot and a control method thereof

Abstract

The application discloses a control system based on a pipe grabbing robot and a control method thereof, and solves the problem of low automation degree in the pipe splicing process in the prior art. The control system based on the pipe grabbing robot comprises a control cabinet, a man-machine interaction module connected with the control cabinet, an image acquisition device connected with the control cabinet and an execution component. The image acquisition device comprises an image acquisition device I arranged at a pipe to-be-grabbed position and an image acquisition device II arranged at a pipe splicing position. The execution component comprises a hydraulic execution unit and an electric execution unit. The control system cooperates with a sensor unit, a hydraulic execution mechanism unit and an electric execution mechanism unit, can intelligently grab a tubular workpiece, finely adjusts the posture and assembles, realizes automatic pipe grabbing operation, guarantees the construction safety of an operator and improves the operation efficiency.

Description

Technical Field

[0001] This invention relates to the field of pipe splicing technology, and in particular to a control system and control method based on a pipe-grabbing robot. Background Technology

[0002] In construction projects such as tunneling, coal mining, and drilling, there are often scenarios involving the handling of heavy pipelines. For example, in oil drilling, pipework consists of rods or tubular components used to connect drilling tools and transmit power; pipework handling is the most labor-intensive stage of the construction process. In shield tunnel construction, mud pipes, sewage pipes, and other pipelines need to be laid as the shield advances, making it a crucial part of the entire tunnel construction cycle. In these scenarios, single pipelines are often several meters long and heavy, typically requiring manual pushing or hoisting. Precisely adjusting the pipeline's position is difficult, necessitating constant adjustments during alignment to ensure proper installation of the two pipe sections. Manual labor is labor-intensive, carries high risks, and impacts construction efficiency.

[0003] In the prior art, such as the control system of a wheeled heavy-duty pipe-grabbing robot with application number 202311764956.4, it relies on a lot of precision equipment such as cameras, inertial navigation, lidar, and total station, which is not very reliable in underground construction.

[0004] The patent application number 202210662033.7 proposes a control system and method for an electric pipe-handling robot. This method involves positioning and controlling the pipe placement and gripping positions between the pipe support box and the wellhead. The operation requires manual determination of the pipe's movement position on the HMI, followed by automatic gripping and movement by the robot. This process is quite cumbersome and does not address the issue of precise assembly after pipe gripping.

[0005] Therefore, it is necessary to design a highly reliable control system and method for this type of robot, capable of gripping tubular workpieces, fine-tuning their posture, and assembling them, to achieve automated pipe gripping operations. Summary of the Invention

[0006] To address the shortcomings in the aforementioned background technology, this invention proposes a control system and control method based on a pipe-grabbing robot, which solves the problem of low automation in the pipe splicing process in the prior art.

[0007] The technical solution of the present invention is implemented as follows: a control system based on a pipe-grabbing robot includes a control cabinet and a human-machine interaction module connected to the control cabinet, as well as an image acquisition device and an execution component connected to the control cabinet.

[0008] The image acquisition device includes image acquisition device I located at the position where the pipe is to be grasped and image acquisition device II located at the pipe splicing position; the execution components include a hydraulic execution unit and an electric execution unit. The robotic arm mechanism is equipped with corresponding hydraulic execution units and sensor units.

[0009] The pipe-grabbing robot includes a robotic arm mechanism and a gripper mechanism with a gripper end effector. The gripper mechanism has at least one active roller gripper. The active roller gripper is equipped with a pair of adjustable wheels that are arranged opposite each other. The adjustable wheels are controlled to extend and retract by an electric actuator. The active roller gripper is equipped with a friction drive wheel driven by the electric actuator. The friction drive wheel drives the pipe section to rotate around its axis under the action of the electric actuator.

[0010] Specifically, the active roller gripper includes a first fixed seat with an opening on one side. The opening of the first fixed seat is provided with a first clamping plate for opening and closing. The clamping surface of the first fixed seat and the clamping surface of the first clamping plate are provided with opposing adjusting wheels. The adjusting wheels are controlled to extend and retract by an electric actuator. The first fixed seat is provided with a friction drive wheel driven by the electric actuator.

[0011] Further preferably, the gripper mechanism also includes a passive ball joint gripper; the ball joint structure of the passive ball joint gripper rotates passively with the tubular workpiece.

[0012] Further preferably, the robotic arm mechanism includes a base, on which a longitudinal moving mechanism is connected via a bottom slewing mechanism. The moving component of the longitudinal moving mechanism is equipped with a lateral moving mechanism, which is connected to a gripper mechanism via a secondary beam. The bottom slewing mechanism is driven by a rotary motor, and the rotary motor is equipped with an angle encoder.

[0013] Further preferably, the longitudinal moving mechanism is driven by the longitudinal hydraulic cylinder of the hydraulic actuator, and the lateral moving mechanism is driven by the lateral hydraulic cylinder of the hydraulic actuator; the longitudinal moving mechanism is equipped with a displacement sensor for detecting its longitudinal moving distance, and the lateral moving mechanism is equipped with a displacement sensor for detecting its lateral moving distance; further preferably, the electric actuator is an electric cylinder and / or a motor; the adjusting wheelset is controlled to extend and retract by the electric cylinder, and the friction drive wheel is driven to rotate by a rolling motor, the rolling motor being equipped with an angle encoder.

[0014] In a further preferred embodiment, the adjusting wheel pair includes an electric cylinder and an I-shaped wheel frame. The vertical beam of the I-shaped wheel frame is connected to the telescopic end of the electric cylinder, the fixed end of the electric cylinder is fixed by a fixing plate frame, and pulleys are provided on both sides of the I-shaped wheel frame.

[0015] Further preferably, the passive ball-joint gripper includes a second ball-joint seat with an opening on one side, and a second clamping plate for opening and closing is provided at the opening of the second ball-joint seat. An inner ball-shaped card seat is connected inside the second ball-joint seat in a ball-joint manner, and pulleys are provided on the working surface of the inner ball-shaped card seat and the working surface of the second clamping plate.

[0016] In a further preferred embodiment, the control cabinet includes a power management module and a controller and a slave coupler connected to the power management module. The output end of the slave coupler is connected to a data acquisition module, which is connected to the input end of the controller. The slave coupler is hardware-coupled to the data acquisition module and the control output module. The data acquisition module is connected to the sensor unit, and the control output module is connected to the actuator.

[0017] A control method for the control system based on the pipe-grabbing robot, comprising the following steps:

[0018] S1, the pipe-grabbing robot is in the initial position, and the control system performs a self-check;

[0019] S2, Image acquisition device I starts to acquire information about the pipe to be grasped at position A1, calculates the pose of the pipe to be grasped, and generates motion path information of the robot from the initial position to position A1 of the pipe to be grasped;

[0020] S3, the generated robot motion path information is transmitted to the controller, the controller controls the robot to move to position A1 of the pipe to be grasped, and grasps the pipe;

[0021] S4, the robot moves along the set path, moving the currently gripping pipe from position A1 to the interface A2 of the previous pipe section;

[0022] S5, Image acquisition device II starts acquiring the image of the previous pipe section, calculates the axial orientation of the previous pipe section, and simultaneously calculates the axial orientation of the current pipe section using data from the robot sensor unit; Based on the axial orientation of the previous pipe section and the axial orientation of the current pipe section, the axial deviation angle between the two is obtained.

[0023] S6, based on the axial deviation angle between the previous pipe section and the current pipe section, the controller controls the extension distance of the adjustment wheel pair to ensure that the axis orientation of the current pipe section in the clamping state is consistent with that of the previous pipe section, and to align the flanges of the two.

[0024] S7, Image acquisition device II acquires the image of the docking point between the current pipe and the previous pipe section, and calculates the deviation angle at the flange connection between the two; based on the deviation angle, the motor is controlled to drive the friction drive wheel to rotate, thereby driving the current pipe clamped to rotate, so that the flange holes of the two docking flanges are aligned.

[0025] S8, the next construction step can be taken;

[0026] S9. Repeat steps S1 to S8 until all pipes are picked up and connected.

[0027] The specific process of step S2 is as follows: S2.1, the image data of the pipe to be grasped at point A1 is acquired through the image acquisition device I, the position and orientation information of the pipe to be grasped in the camera coordinate system are calculated through feature detection, and then coordinate transformation is performed to convert the orientation information of the pipe to be grasped to the robot coordinate system.

[0028] S2.2, using a motion planning algorithm, generate the shortest motion path for the robot from its initial position to its target position; and perform interpolation and smoothing on the generated shortest path to generate motion path information for the robot from its initial position to the position A1 of the gripper to be grasped.

[0029] The specific process of step S5 is as follows: S5.1 The steps for calculating the orientation of the axis of the previous pipe section are as follows: First, image acquisition device II is used to acquire image information of the previous pipe section. By scanning, the edge pixel coordinates of the pipe openings at both ends of the previous pipe section are obtained. The least squares method is used to fit the contours of the pipe openings at both ends to generate standard circles for the pipe openings at both ends. Specifically:

[0030] The coordinates of the edge point set are Let the radius of the circle be... The coordinates of the center of the circle are Then the equation of the circle is ,in For random error; minimum sum of squared errors According to the least squares principle, we know Solving the above system of linear equations yields the coordinates of the center of the pipe opening at the beginning. Coordinates of the center of the tailpipe opening ;

[0031] Then, based on the center coordinates of the pipe opening at the beginning of the pipe fitting in the previous section... Coordinates of the center of the tailpipe opening and the known length of the pipe in the previous section. Calculate the orientation of the axis of the previous pipe section:

[0032] The angle in the X direction is ,

[0033] The angle in the Y direction is ,

[0034] The orientation of the axis of the previous pipe section is: ;

[0035] S5.2 The steps for calculating the current pipe clamp axis orientation are as follows: Assume there are four electric cylinders in the active roller gripper, denoted as A, B, C, and D, and the total stroke of the four electric cylinders are respectively... The height between the upper active roller grippers is H.

[0036] Then the deviation angle in the X direction ,

[0037] Y-direction deviation angle The current orientation of the clamping tool's axis is... .

[0038] The specific process of step S7 is as follows: Image acquisition device II acquires an image of the connection point between the current pipe fitting and the previous pipe fitting, and calculates the angular deviation between the two flange holes closest to each other between the current pipe fitting and the previous pipe fitting using image processing technology. , To ensure the current pipe needs to be rotated clockwise, If the value is negative, the current pipe needs to be rotated counterclockwise. The angle of rotation of the rolling motor corresponding to the friction drive wheel that drives the current pipe is... Then there is , where k is the number of unit angles by which the clamped pipe rotates.

[0039] The beneficial effects of this invention are as follows: This invention is based on a control system for a pipe-gripping robot with active adjustment of pipe segment posture. The passive ball-joint gripper has three degrees of freedom in rotational directions due to its ball-joint connection. The active roller gripper uses a friction drive wheel with autonomous drive and an adjustment wheel pair to cooperate. Through the structure of the upper gripper ball joint, the tubular workpiece has three degrees of rotational freedom. Under the rotation of the friction drive wheel, it can rotate around the axis. With the cooperation of the symmetrically arranged posture adjustment wheel pairs, it can swing in the other two degrees of freedom. Through the actions of the passive ball-joint gripper and the active roller gripper, the rotation of the tubular workpiece in three degrees of freedom, i.e., posture adjustment, is realized, meeting the high-precision positioning requirements during the assembly of tubular workpieces.

[0040] The control system of this invention utilizes the cooperation of sensor units, hydraulic actuator units, and electric actuator units to perform intelligent gripping, posture fine-tuning, and assembly of tubular workpieces, realizing automated pipe gripping operations, ensuring the construction safety of workers, and improving work efficiency. Attached Figure Description

[0041] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the pipe-grabbing robot of the present invention.

[0043] Figure 2 This is a schematic diagram of the passive ball joint gripper structure of the present invention.

[0044] Figure 3 This is a schematic diagram of the active roller gripper structure of the present invention.

[0045] Figure 4 This is a schematic diagram of the arrangement of the active roller type gripper adjustment wheel pair of the present invention.

[0046] Figure 5 This is a block diagram illustrating the control system principle of the present invention.

[0047] Figure 6 This is a schematic diagram of the control system layout of the present invention.

[0048] Figure 7 A schematic diagram of image acquisition by image acquisition device II.

[0049] Figure 8 This is a schematic diagram showing the current orientation of the clamping pipe axis.

[0050] Figure 9 This is a schematic diagram of the adjustment of the flange of the two-section pipe fitting.

[0051] Figure 10 This is a schematic diagram showing the alignment of the flange holes of two pipe sections.

[0052] In the figure: 1. Seat body; 2. Bottom rotation mechanism; 3. Longitudinal movement mechanism; 4. Configuration mechanism; 5. Traction rope; 6. Guide wheel; 7. Lateral movement mechanism; 8. Sub-beam; 9. Passive ball joint gripper; 902. Second clamping plate; 904. Pulley; 905. Second ball joint seat; 907. Inner ball type seat; 10. Active roller gripper; 10. First clamping plate; 1002. Adjusting wheel pair; 1003. First fixed seat; 1004. Friction drive wheel; 1005. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] Example 1, as Figure 5 As shown, a control system based on a pipe-grabbing robot includes a control cabinet and a human-machine interface (HMI) connected to the control cabinet. The HMI is a human-machine interface, also called a user interface or user interface, which serves as the medium for interaction and information exchange between the system and the user. It converts information from its internal form to a human-readable form. The HMI is connected to the controller via a network cable and transmits data via Modbus TCP or other bus protocols. The control system also includes an image acquisition device and actuators connected to the control cabinet. The control system comprises a control cabinet, an HMI, sensor units, a hydraulic actuator unit, and an electric actuator unit. The control cabinet is installed near the pipe-grabbing robot and connected to the power supply system via cables. The HMI is installed at the operating position of the equipment to provide an operation display interface, and the HMI is connected to the control cabinet via a communication cable. The sensor unit is installed on the pipe-grabbing robot body, and all sensor cables are bundled into a multi-core cable through a junction box and connected to the control cabinet. The hydraulic actuator unit is installed on the pipe-grabbing robot body and connected to the hydraulic actuator via oil pipes. All hydraulic valve cables are bundled into a multi-core cable through a junction box and connected to the control cabinet. The electric actuator unit is installed on the pipe-grabbing robot body, and all hydraulic valve cables are bundled into a multi-core cable through a junction box and connected to the control cabinet.

[0055] Preferably, the control cabinet includes a power management module and a controller and a slave coupler connected to the power management module. The output end of the slave coupler is connected to a data acquisition module, which is connected to the input end of the controller. The slave coupler is hardware-coupled to the data acquisition module and the control output module. The data acquisition module is connected to the sensor unit, and the control output module is connected to the actuator.

[0056] Specifically, the control cabinet includes a power management module, a controller, a slave coupler, a data acquisition module, a control output module, and an emergency stop module. The power management module comprises a circuit breaker, a DC regulated power supply, and a current distribution module. The circuit breaker is connected to the DC regulated power supply to cut off the upstream power supply. The output of the DC regulated power supply is connected to the input of the current distribution module. The multiple outputs of the current distribution module supply power to different parts of the control system. When a short circuit, overload, or short circuit occurs in one of the outputs, the power supply to that output can be automatically cut off, and an alarm signal can be output, thus providing protection and enabling timely fault location.

[0057] The controller consists of a CPU and an industrial computer, which are connected by a communication cable. The CPU is used for logic control, motion control, process control, data processing, and communication networking; the industrial computer is used to receive images captured by the vision camera in real time, calculate the coordinate position of the pipe through a vision calculation program, perform robot path planning and obstacle avoidance based on this coordinate position, and send the path points to the CPU for execution.

[0058] The slave coupler includes a PN bus coupler, which connects to the PLC via a communication bus. The bus coupler is hardware-coupled to the data acquisition module and the control output module. By connecting an I / O module to the PN bus coupler, an I / O device station is created, thereby configuring the I / O device as a PN node into the CPU network, enabling the CPU to control the I / O device.

[0059] The data acquisition module includes a digital input module and an analog input module. By connecting the sensor cable to the corresponding data acquisition module, the sensor data can be read.

[0060] The control output module includes a digital output module, an analog output module, a relay, and a current amplifier. By connecting the output module to the controlled object such as a solenoid valve or an electric cylinder via a cable, motion control of the actuator can be achieved.

[0061] The emergency stop module includes an emergency stop button, a reset button, and a safety relay. The emergency stop button, reset button, and safety relay form an emergency stop circuit through hard wiring, which is used for emergency stop handling in case of emergency. Pressing the emergency stop button disconnects the power supply to the power management module, de-energizes all hydraulic valves and electric cylinders, and stops the equipment from running. To restart the equipment, the emergency stop button must be reset and the reset button must be pressed.

[0062] The HMI (Hybrid Management Interface) is used to display the status of various devices on the pipe-grabbing robot, as well as the pipe-grabbing process and operations. It includes the following functional areas: Device Status Area, Manual Operation Area, Automatic Operation Area, Vision Calculation Area, Path Planning Area, and Workflow Area. Specifically, the Device Status Area displays all robot sensor values ​​and determines if there are any hardware anomalies; the Manual Operation Area is used to manually adjust the movement of individual joints, such as controlling the left / right rotation of the bottom slewing mechanism, mainly for equipment debugging and resetting actions in fault conditions; the Automatic Operation Area controls the robot's pipe-grabbing and docking in automatic mode, with manual and automatic modes switched via buttons; the Vision Calculation Area displays the images captured and processed by the vision camera, and shows the calculated motion coordinates; the Path Planning Area outputs the coordinates of the robot's path planning points and sends them to the robot for execution; and the Workflow Area displays the current workflow in automatic mode, such as currently performing vision capture, pipe-grabbing, transfer, or docking.

[0063] The sensor unit includes a bottom rotation mechanism angle sensor, a longitudinal movement mechanism displacement sensor, a horizontal movement mechanism displacement sensor, four electric cylinders built-in displacement sensors for the lower claw, a lower claw rolling motor angle sensor, and a vision camera.

[0064] Specifically, such as Figure 6 As shown, the image acquisition device in this embodiment includes an image acquisition device I100 positioned at the pipe gripping location and an image acquisition device II200 positioned at the pipe splicing location; the execution components include a hydraulic execution unit and an electric execution unit; the image acquisition device I100 and the image acquisition device II200 can be CCD cameras. The hydraulic execution unit includes a hydraulic pump station, a bottom slewing mechanism hydraulic valve, a longitudinal movement mechanism hydraulic valve, a horizontal movement mechanism hydraulic valve, an upper jaw opening and closing hydraulic valve, a lower jaw opening and closing hydraulic valve, and their respective corresponding hydraulic cylinders. Hydraulic valves A and B are connected to their corresponding hydraulic cylinders via oil pipes, and hydraulic valves P and T are connected to the hydraulic pump station via oil pipes. The hydraulic valves can be on / off valves, proportional directional valves, servo valves, etc. The electric execution unit includes electric cylinders for four sets of attitude adjustment wheels within the sidewall of the active roller gripper and a rolling motor on the inner sidewall of the active roller gripper.

[0065] Specifically, the pipe-grabbing robot includes a robotic arm mechanism and a gripper mechanism with an end effector on the robotic arm mechanism. The gripper mechanism includes at least one active roller gripper 10, on which an adjustable wheel pair 1003 is provided. The adjustable wheel pair 1003 is controlled to extend and retract by an electric actuator. The active roller gripper is provided with a friction drive wheel 1005 driven by an electric actuator. The friction drive wheel 1005 drives the pipe section to rotate around its axis under the action of the electric actuator.

[0066] like Figure 3 ,4 As shown, the active roller gripper 10 has the power to drive a tubular workpiece to rotate around its axis. Specifically, it includes a first fixed seat 1004 with an opening on one side. The opening of the first fixed seat 1004 is provided with a first clamping plate 1002 for opening and closing. The first clamping plate 1002 serves as the clamping mechanism of the active roller gripper, used to press the workpiece into the first fixed seat 1004, thus realizing the clamping and releasing of the tubular workpiece by the active roller gripper. Adjustable wheelsets 1003 are provided oppositely on both the clamping surface of the first fixed seat 1004 and the clamping surface of the first clamping plate 1002. The adjustable wheelsets 1003 are controlled to extend and retract by an electric actuator. The first fixed seat 1004 is provided with a friction drive wheel 1005 driven by the electric actuator; the friction drive wheel 1005, in contact with the tubular workpiece, can drive the tubular workpiece to rotate around its axis. The robotic arm mechanism is provided with a corresponding hydraulic actuator and sensor unit.

[0067] As a further preferred embodiment, the gripper mechanism also includes a passive ball-joint gripper 9; the ball-joint structure of the passive ball-joint gripper passively rotates with the tubular workpiece. The passive ball-joint gripper 9 and the active roller gripper 10 provide multi-stage clamping for the tubular workpiece, ensuring gripping stability. The passive ball-joint gripper 9 and the active roller gripper 10 work together primarily for gripping, tightening, and adjusting the posture of the tubular workpiece, meeting the high-precision requirements of tubular workpiece assembly. The active roller gripper has the power to drive the tubular workpiece to rotate around its axis, and the ball-joint structure of the passive ball-joint gripper passively rotates with the tubular workpiece; this is used to adjust the posture of the tubular workpiece to achieve intelligent, high-precision adjustment and splicing.

[0068] like Figure 2 As shown, the passive ball-joint gripper 9 includes a second ball-joint seat 905 with an opening on one side. A second clamping plate 902 for opening and closing is provided at the opening of the second ball-joint seat 905. An inner ball-shaped clamping seat 907 is connected to the second ball-joint seat 905 via a ball-joint connection. Both the working surface of the inner ball-shaped clamping seat 907 and the working surface of the second clamping plate 902 are provided with pulleys 904. The pulleys allow the tubular workpiece to rotate around its axis after being clamped.

[0069] Taking a jaw clamping mechanism comprising an active roller type jaw 10 and a passive ball joint type jaw 9 as an example, the active roller type jaw 10 is defined as the lower jaw, and the passive ball joint type jaw 9 is defined as the upper jaw. Since the upper jaw adopts the form of a ball joint, after the upper and lower jaws clamp the workpiece, the workpiece has three degrees of freedom. At this time, the adjustment of these three degrees of freedom is achieved by the coordinated action of the lower jaw posture adjustment wheel pair. The specific adjustment method is as follows: when the posture adjustment wheel pair on one side of the lower jaw extends, the posture adjustment wheel pair on the other side, which is symmetrically installed with it, retracts. Through the coordinated action of the symmetrical wheel pair, the swing of the clamped tubular workpiece is realized, thereby achieving the purpose of posture adjustment.

[0070] Example 2: A control system based on a pipe-grabbing robot. This example further optimizes Example 1. The robotic arm mechanism includes a base 1, on which a longitudinal moving mechanism 3 is connected via a bottom rotating mechanism 2. A lateral moving mechanism 7 is mounted on the moving part of the longitudinal moving mechanism 3. The lateral moving mechanism 7 is connected to a gripper mechanism via a secondary beam 8. The bottom rotating mechanism 2 is driven by a rotary motor, which is equipped with an angle encoder for precisely adjusting the circumferential angle of the robotic arm mechanism.

[0071] Preferably, the bottom slewing mechanism 2 includes a turntable rotatably mounted on the base 1, the turntable being connected to a drive component mounted on the base 1; the bottom slewing mechanism can be in the form of a slewing reducer, which is equipped with an angle encoder. The longitudinal moving mechanism 3 is driven by the longitudinal hydraulic cylinder of the hydraulic actuator, and the lateral moving mechanism 7 is driven by the lateral hydraulic cylinder of the hydraulic actuator; the longitudinal moving mechanism 3 is equipped with a displacement sensor for detecting its longitudinal moving distance, and the lateral moving mechanism 7 is equipped with a displacement sensor for detecting its lateral moving distance. The displacement sensor and the angle encoder constitute a sensor unit.

[0072] Preferably, the electric actuator is an electric cylinder and / or a motor; the adjusting wheel pair 1003 is controlled to extend and retract by the electric cylinder, and the friction drive wheel 1005 is driven to rotate by a rolling motor. The rolling motor is equipped with an angle encoder. The active roller gripper 10, through the rotation of its friction drive wheel 1005, drives the tubular workpiece to rotate around its axis, adjusting the circumferential angle of the tubular workpiece. The active roller gripper achieves the adjustment of the tubular workpiece's posture through four symmetrically arranged electric cylinders and two symmetrically arranged adjusting wheel pairs, specifically, such as extending one side's telescopic cylinder while retracting the other side, thus achieving rotation; the advantage of this structure is that the workpiece's posture calculation is simple and the control is simple, but it can also be designed with three pairs or other numbers.

[0073] Preferably, the adjusting wheelset 1003 includes an electric cylinder and an I-shaped wheel frame. The vertical beam of the I-shaped wheel frame is connected to the telescopic end of the electric cylinder, and the fixed end of the electric cylinder is fixed by a fixing plate frame. Pulleys are provided on both sides of the I-shaped wheel frame. The passive ball-joint gripper has no drive unit, while the active roller gripper uses symmetrical cylinders, motors, etc., to achieve workpiece rotation and two-way oscillation. Posture adjustment is achieved through the adjustment of the active roller gripper and the follow-up movement of the passive ball-joint gripper. Alternatively, the functions of the passive ball-joint gripper and the active roller gripper can be interchanged as needed, with the passive ball-joint gripper driving and the active roller gripper following.

[0074] In addition, a corresponding configuration mechanism 4 can be configured on the robotic arm mechanism of the pipe gripping robot as needed. The configuration mechanism 4 is equipped with a corresponding guide wheel 6 to realize the reversal of the traction rope 5, so as to achieve the force balance of the double gripper mechanism and meet the requirements of safe construction.

[0075] Example 3, a control method for a control system based on a pipe-grabbing robot as described in Example 1 or 2, wherein the gripper mechanism includes an active roller gripper 10 and a passive ball joint gripper 9, wherein the active roller gripper 10 is defined as the lower gripper and the passive ball joint gripper 9 is defined as the upper gripper.

[0076] The control method steps of the above control system are as follows:

[0077] S1, the pipe-grabbing robot is in the initial position, and the control system performs a self-check. The self-check contents are as follows: (1) Communication quality, including PN bus communication between the CPU and the slave coupler, and Ethernet communication between the CPU and the HMI; (2) Power management, specifically the status of each power channel of the current distributor. If there is a fault in the channel, an alarm signal will be output; (3) Sensor data, by reading the data of each sensor, it is determined whether there is a sensor data abnormality.

[0078] S2, after the pipe is transported to the gripping position, the operator confirms it and presses the one-button gripping button on the HMI. When the pipe enters the area, image acquisition device I detects it and issues an indication signal. At this point, a second confirmation is performed manually to confirm that the pipe has been transported to the gripping position and is securely placed. Image acquisition device I 100 begins acquiring information about the pipe to be gripped at position A1, calculates the pose of the pipe, and generates the robot's motion path information from its initial position to position A1. Specifically:

[0079] S2.1, The image data of the pipe to be grasped at point S1 is acquired by the image acquisition device I100. The position and orientation information of the pipe to be grasped in the camera coordinate system are calculated by feature detection such as template matching and YOLO algorithm. Then, coordinate transformation is performed to convert the orientation information of the pipe to be grasped into the robot coordinate system.

[0080] S2.2 A motion planning algorithm, such as Dijkstra's shortest path algorithm, is used to generate the shortest motion path for the robot from its initial position to its target position A1. The generated shortest path is then interpolated and smoothed to reduce jitter and instability during motion. Finally, the motion path information for the robot from its initial position to the position A1 of the gripper is generated. A fence is set up near the planned motion path to ensure there are no obstacles within the fence, and personnel are prohibited from entering the area.

[0081] S3 transmits the generated robot motion path information to the controller, which then controls the robot to move to position A1 of the pipe to be grasped and grasp the pipe.

[0082] S4, the robot moves along the set path, moving the currently gripping pipe from position A1 to the interface A2 of the previous pipe section. Except for the first operation, which requires manual setting of the coordinates of position A2, the controller can remember the previous position of A2 each time it works automatically, thus automatically executing the process from the initial position to A1 and then to A2, without the need for manual resetting.

[0083] S5, the image acquisition device II200 starts acquiring the image of the previous pipe section, calculates the axial orientation of the previous pipe section, and simultaneously calculates the axial orientation of the current pipe section using data from the robot sensor unit; based on the axial orientation of the previous pipe section and the axial orientation of the current pipe section, the axial deviation angle between the two is obtained.

[0084] The camera used in this step is a CCD camera. The acquired image mainly consists of a background and target with relatively uniform grayscale. Filtering removes noise that could affect the algorithm's accuracy. The filtered image is then converted to a binary image using the maximum variance automatic thresholding method, making the pipe area black and the rest white. The camera is mounted at a certain angle to the pipe, covering both ends of the pipe. Scanning is used to obtain the edge pixel coordinates of the pipe ends (the far end is not a complete circle, such as...). Figure 7 (As shown).

[0085] Specifically: such as Figure 8 As shown, the steps for calculating the axis orientation of the previous pipe section in S5.1 are as follows: First, the image acquisition device II200 is used to acquire the image information of the previous pipe section. The edge pixel coordinates of the pipe openings at both ends of the previous pipe section are obtained by scanning. The contours of the pipe openings at both ends are fitted using the least squares method to generate standard circles for the pipe openings at both ends. Specifically:

[0086] The coordinates of the edge point set are Let the radius of the circle be... The coordinates of the center of the circle are Then the equation of the circle is ,in For random error; minimum sum of squared errors According to the least squares principle, we know Solving the above system of linear equations yields the coordinates of the center of the pipe opening at the beginning. Coordinates of the center of the tailpipe opening ;

[0087] Then, based on the center coordinates of the pipe opening at the beginning of the pipe fitting in the previous section... Coordinates of the center of the tailpipe opening and the known length of the pipe in the previous section. Calculate the orientation of the axis of the previous pipe section:

[0088] The angle in the X direction is ,

[0089] The angle in the Y direction is ,

[0090] The orientation of the axis of the previous pipe section is: ;

[0091] S5.2 The steps for calculating the current pipe clamp axis orientation are as follows: Assume there are four electric cylinders in the active roller gripper, denoted as A, B, C, and D, and the total stroke of the four electric cylinders are respectively... The height between the upper active roller grippers is H.

[0092] Then the deviation angle in the X direction ,

[0093] Y-direction deviation angle The current orientation of the clamping pipe axis is... .

[0094] S6, such as Figure 9 As shown, based on the axial deviation angle between the previous pipe section and the current pipe section, the controller controls the extension distance of the adjustment wheel pair 1003 to ensure that the axis orientation of the current pipe section in the clamping state is consistent with that of the previous pipe section, and to align the flanges of the two.

[0095] Specifically, based on the current pipe shaft orientation and the previous pipe shaft orientation calculated by S5, the angular deviation between the two is decomposed into X and Y directions. Based on the angular deviation in each direction, the electric cylinder in that direction is controlled to extend or shorten. During this process, the camera calculates the angular deviation in real time and guides the electric cylinder to move until the angular deviation is eliminated.

[0096] S7, such as Figure 10 As shown, the image acquisition device II200 acquires images of the docking point between the current pipe and the previous pipe section, calculates the deviation angle at the flange connection between the two; based on the deviation angle, the motor is controlled to drive the friction drive wheel 1005 to rotate, thereby driving the clamped current pipe to rotate, so that the flange holes of the two docking flanges are aligned.

[0097] Specifically, the image acquisition device II200 acquires images of the connection point between the current pipe fitting and the previous pipe fitting, and calculates the angular deviation between the two closest flange holes of the current pipe fitting and the previous pipe fitting using image processing technology. , To ensure the current pipe needs to be rotated clockwise, If the value is negative, the current pipe needs to rotate counterclockwise. The angle of rotation of the rolling motor corresponding to the friction drive wheel 1005 that drives the current pipe rotation is... Then there is , where k is the number of unit angles by which the clamped pipe rotates.

[0098] S8, then take the next construction step such as fixing with bolts;

[0099] S9. Repeat steps S1 to S8 until all pipes are picked up and connected.

[0100] The control system and method for the pipe-grabbing robot proposed in this invention enable the robot to automatically grab pipes and precisely align and assemble them, thereby improving the automation level of the equipment and ensuring the personal safety of the operators.

[0101] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A control system based on a pipe-grabbing robot, comprising a control cabinet and a human-machine interface module connected to the control cabinet, characterized in that: It also includes image acquisition devices and execution components connected to the control cabinet; The image acquisition device includes image acquisition device I (100) set at the position where the pipe is to be grasped and image acquisition device II (200) set at the pipe splicing position; the actuation components include a hydraulic actuation unit and an electric actuation unit; The pipe-grabbing robot includes a robotic arm mechanism and a gripper mechanism with a gripper end set at the end of the robotic arm mechanism; the gripper mechanism includes at least one active roller gripper (10); the active roller gripper is provided with an adjustable wheel pair (1003) arranged opposite to each other, the adjustable wheel pair (1003) is controlled to extend and retract by an electric actuator, and the active roller gripper is provided with a friction drive wheel (1005) driven by an electric actuator, the friction drive wheel (1005) drives the pipe section to rotate around its axis under the action of the electric actuator; The robotic arm mechanism is equipped with corresponding hydraulic actuators and sensor units; The adjusting wheelset includes an electric cylinder and an I-shaped wheel frame. The vertical beam of the I-shaped wheel frame is connected to the telescopic end of the electric cylinder. The fixed end of the electric cylinder is fixed by a fixed plate frame. Pulleys are provided on both sides of the I-shaped wheel frame.

2. The control system based on the pipe-grabbing robot according to claim 1, characterized in that: The active roller gripper (10) includes a first fixed seat (1004) with an opening on one side. The opening of the first fixed seat (1004) is provided with a first pressing plate (1002) for opening and closing. The clamping surface of the first fixed seat (1004) and the clamping surface of the first pressing plate (1002) are provided with opposing adjusting wheels (1003). The first fixed seat (1004) is provided with a friction drive wheel (1005) driven by an electric actuator.

3. The control system based on the pipe-grabbing robot according to claim 1 or 2, characterized in that: The gripper mechanism also includes a passive ball joint gripper (9); the ball joint structure of the passive ball joint gripper rotates passively with the tubular workpiece.

4. The control system based on the pipe-grabbing robot according to claim 1, characterized in that: The robotic arm mechanism includes a base (1), on which a longitudinal moving mechanism (3) is connected via a bottom rotating mechanism (2). A transverse moving mechanism (7) is provided on the moving part of the longitudinal moving mechanism (3), and the transverse moving mechanism (7) is connected to the gripper mechanism via a sub-beam (8).

5. The control system based on the pipe-grabbing robot according to claim 4, characterized in that: The longitudinal moving mechanism (3) is driven by the longitudinal hydraulic cylinder of the hydraulic actuator, and the lateral moving mechanism (7) is driven by the lateral hydraulic cylinder of the hydraulic actuator. The longitudinal moving mechanism (3) is equipped with a displacement sensor for detecting its longitudinal moving distance, and the lateral moving mechanism (7) is equipped with a displacement sensor for detecting its lateral moving distance. The bottom rotating mechanism (2) is driven by a rotary motor, and the rotary motor is equipped with an angle encoder.

6. The control system based on the pipe-grabbing robot according to any one of claims 1, 2, 4 and 5, characterized in that: The adjustment wheel pair (1003) is controlled to extend and retract by an electric cylinder, and the friction drive wheel (1005) is driven to rotate by a rolling motor, which is equipped with an angle encoder.

7. The control system based on the pipe-grabbing robot according to claim 3, characterized in that: The passive ball joint gripper (9) includes a second ball joint seat (905) with an opening on one side. The opening of the second ball joint seat (905) is provided with a second pressure plate (902) for opening and closing. An inner ball joint seat (907) is connected to the second ball joint seat (905) in a ball joint manner. Both the working surface of the inner ball joint seat (907) and the working surface of the second pressure plate (902) are provided with pulleys.

8. The control system based on the pipe-grabbing robot according to claim 1, characterized in that: The control cabinet includes a power management module and a controller and a slave coupler connected to the power management module. The output of the slave coupler is connected to a data acquisition module, which is connected to the input of the controller. The slave coupler is hardware-coupled to the data acquisition module and the control output module. The data acquisition module is connected to the sensor unit, and the control output module is connected to the actuator.

9. A control method for a control system based on a pipe-grabbing robot as described in any one of claims 1 to 8, characterized in that: The claw clamping mechanism includes an active roller type jaw (10) and a passive ball joint type jaw (9). The active roller type jaw (10) is defined as the lower jaw, and the passive ball joint type jaw (9) is defined as the upper jaw. The control method steps are as follows: S1, the pipe-grabbing robot is in the initial position, and the control system performs a self-check; S2, Image acquisition device I (100) starts to acquire information about the pipe to be grasped at position A1, calculates the pose of the pipe to be grasped, and generates motion path information of the robot from the initial position to position A1 of the pipe to be grasped; S3, the generated robot motion path information is transmitted to the controller, the controller controls the robot to move to position A1 of the pipe to be grasped, and grasps the pipe; S4, the robot moves along the set path, moving the currently gripping pipe from position A1 to the interface A2 of the previous pipe section; S5, Image acquisition device II (200) starts to acquire the image of the previous pipe section, calculates the axis orientation of the previous pipe section, and calculates the axis orientation of the current pipe section through the data of the robot sensor unit; and obtains the axial deviation angle between the two based on the axis orientation of the previous pipe section and the axis orientation of the current pipe section. S6, based on the axial deviation angle between the previous pipe section and the current pipe section, the controller controls the extension distance of the adjustment wheel pair (1003) to make the axis orientation of the current pipe section in the clamping state consistent with that of the previous pipe section, and to align the flanges of the two pipe sections. S7, Image acquisition device II (200) acquires the image of the docking point between the current pipe and the previous pipe, and calculates the deviation angle at the flange connection between the two; based on the deviation angle, the motor is controlled to drive the friction drive wheel (1005) to rotate, thereby driving the current pipe being clamped to rotate, so that the flange holes of the two docking flanges are aligned. S8, the next construction step can be taken; S9. Repeat steps S1 to S8 until all pipes are picked up and connected.

10. The control method for the control system based on the pipe-grabbing robot according to claim 9, characterized in that: The specific process of step S2 is as follows: S2.1, the image data of the pipe to be grasped at point A1 is obtained through the image acquisition device I (100), the position and posture information of the pipe to be grasped in the camera coordinate system are calculated through feature detection, and then the coordinate transformation is performed to convert the posture information of the pipe to be grasped to the robot coordinate system. S2.2, using a motion planning algorithm, generate the shortest motion path for the robot from its initial position to its target position; and perform interpolation and smoothing on the generated shortest path to generate motion path information for the robot from its initial position to the position A1 of the gripper to be grasped.

11. The control method for the control system based on the pipe-grabbing robot according to claim 10, characterized in that: The specific process of step S5 is as follows: S5.1 The steps for calculating the orientation of the axis of the previous pipe section are as follows: First, the image acquisition device II (200) is used to acquire the image information of the previous pipe section. The edge pixel coordinates of the pipe openings at both ends of the previous pipe section are obtained by scanning. The contours of the pipe openings at both ends are fitted using the least squares method to generate the standard circles of the pipe openings at both ends. Specifically: The coordinates of the edge point set are Let the radius of the circle be... The coordinates of the center of the circle are Then the equation of the circle is ,in For random error; minimum sum of squared errors According to the least squares principle, we know Solving the above system of linear equations yields the coordinates of the center of the pipe opening at the beginning. Coordinates of the center of the tailpipe opening ; Then, based on the center coordinates of the pipe opening at the beginning of the pipe fitting in the previous section... Coordinates of the center of the tailpipe opening and the known length of the pipe in the previous section. Calculate the orientation of the axis of the previous pipe section: The angle in the X direction is , The angle in the Y direction is , The orientation of the axis of the previous pipe section is: ; S5.2 The steps for calculating the current pipe clamp axis orientation are as follows: Assume there are four electric cylinders in the active roller gripper, denoted as A, B, C, and D, and the total stroke of the four electric cylinders are respectively... The height between the upper active roller grippers is H. Then the deviation angle in the X direction , Y-direction deviation angle , The current orientation of the clamping pipe axis .

12. The control method for the control system based on the pipe-grabbing robot according to claim 9, characterized in that: The specific process of step S7 is as follows: Image acquisition device II (200) acquires the image of the docking point between the current pipe fitting and the previous pipe fitting, and calculates the angular deviation between the two flange holes closest to each other between the current pipe fitting and the previous pipe fitting through image processing technology. , To ensure the current pipe needs to be rotated clockwise, If the value is negative, the current pipe needs to rotate counterclockwise. The angle of rotation of the rolling motor corresponding to the friction drive wheel (1005) that drives the current pipe to rotate is... Then there is , where k is the number of unit angles by which the clamped pipe rotates.

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