A four-degree-of-freedom pipe-grabbing robotic arm control system and its control method

Abstract

This invention discloses a four-degree-of-freedom pipe-grabbing robotic arm control system and its control method, including a robotic arm body control section and a driller's cab control section. The robotic arm body control section is equipped with a corresponding main controller, and encoders and proximity switches are respectively set for the gripping, lifting, rotating, and flipping of the robotic arm. Signals are collected through a high-precision counting module and an analog input module to achieve precise motion control of the robotic arm, realizing accurate positioning of the robotic arm's height, rotation position, and flipping angle. The driller's cab control section is set up, which allows for centralized observation and control in multiple modes through a remote operation terminal. In automated live-line operations, the four-degree-of-freedom pipe-grabbing robotic arm replaces traditional hoists and hydraulic winches for conveying pipe columns, freeing operators from heavy physical labor and the safety risks of operating on high-level platforms. Various interlocking protections ensure equipment safety.

Description

Technical Field

[0001] This invention relates to the field of live well workover technology. More specifically, this invention relates to a four-degree-of-freedom manipulator control system and its control method. Background Technology

[0002] Traditional live-line working equipment primarily relies on manual labor to transport the tubing string from the ground to the elevated working platform. Operators use a hydraulic winch to hoist the tubing string couplings onto a fixed pulley on the mast of the elevated platform using a wire rope and clamps, then control the hydraulic winch to lift the tubing string to the platform. This method is relatively inefficient, carries the risk of tubing loss due to human error, and poses a significant safety risk to personnel escaping in the event of a blowout or tubing run-through. Using a robotic arm to grasp the tubing string, clamp it to the wellhead for docking, and retrieve it after use involves different postures and positions for each retrieval, requiring greater space and path movement. The accuracy and precision of the tubing grasp will affect the subsequent docking at the wellhead. Currently, there is a lack of systematic control over the robotic arm to ensure the accuracy and safety of tubing string movement and positioning. Summary of the Invention

[0003] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0004] Another objective of this invention is to provide a four-degree-of-freedom pipe-grabbing robotic arm control system and its control method to solve the technical problem of the lack of systematic control in existing pipe column transportation.

[0005] To achieve these objectives and other advantages according to the present invention, in one aspect, a four-degree-of-freedom pipe-grabbing manipulator control system is provided, comprising a main controller for the manipulator body, an amplifier, a multi-valve assembly, a safety barrier, multiple proximity switches, multiple safety isolation barriers, a displacement sensor, encoder one, encoder two, and a remote operation terminal, for controlling the operation of the pipe-grabbing manipulator. The pipe-grabbing manipulator is equipped with a pipe-grabbing arm control box, a hydraulic valve island box, a lifting and lowering mechanical pipe-grabbing mechanism, a rotating mechanism, a gear and rack lifting mechanism, and a tilting mechanism. The main controller for the manipulator body is located inside the pipe-grabbing arm control box and is communicatively connected to the remote operation terminal. The multi-valve assembly is installed on the hydraulic valve island box. The main controller for the manipulator body is equipped with a high-precision counting module and an analog input module. Encoder one is located in the rotating mechanism. The encoder two is installed on the gear and rack lifting mechanism. The main controller of the robotic arm is connected to the encoder one through a high-precision counting module for real-time positioning and acquisition of the robotic arm's rotation position signal. The main controller of the robotic arm is also connected to the encoder two through the high-precision counting module for real-time positioning and acquisition of the height signal of the gear and rack lifting mechanism. The main controller of the robotic arm is connected to the flipping mechanism through an analog input module for real-time positioning and acquisition of the robotic arm's flipping angle signal. The main controller of the robotic arm is connected to the multi-valve group through an amplifier to realize the proportional control of the valves. The main controller of the robotic arm is connected to the proximity switch through a safety isolation barrier. The proximity switch collects status signals including the robotic arm's rotation position, gripper with tube, and gripper without tube status signals.

[0006] Preferably, the rotating mechanism is provided with three rotating positions: a waiting position, a pipe row position, and a wellhead position. Each rotating position is provided with a proximity switch. The main controller of the robotic arm body is connected to the three proximity switches of the rotating mechanism through a safety isolation fence to achieve precise point positioning and position protection of the rotating mechanism at the three positions.

[0007] Preferably, the flipping mechanism has a built-in magnetostrictive displacement sensor to collect displacement signals. The main controller of the robotic arm is connected to the magnetostrictive displacement sensor for precise positioning of the flipping angle of the robotic arm. The flipping mechanism is provided with two flipping points, corresponding to the flipping mechanism being in a completely horizontal state and a vertical state. Each flipping point is provided with a proximity switch. The main controller of the robotic arm is connected to the two proximity switches of the flipping mechanism through another safety barrier to achieve precise positioning and position protection of the flipping mechanism in the horizontal and vertical positions.

[0008] Preferably, the upper and lower mechanical pipe gripping mechanism includes an upper ring gripper, a lower ring gripper, an upper clamping hand, a lower clamping hand, a lower clamping hand floating mechanism, a ring gripping and clamping opening and closing position detection sensor, a ring gripper containing or not containing pipe string detection sensor, and a lower clamping hand floating limit detection sensor, which respectively realize the ring gripping and centering function of pipe string, the upper and lower mechanical gripper pipe string clamping function, and the wellhead downward connection function.

[0009] Preferably, the control system of the pipe-grabbing robotic arm has three operating modes: valve stem, remote control, and driller's cabin. The driller's cabin includes an integrated remote operation terminal and two touch screens connected to the remote operation terminal, as well as operating components. The remote control is connected to the main controller of the robotic arm and is in manual operation mode. It is used to remotely send control commands and receive data signals, serving as the control unit of the pipe-grabbing robotic arm to control the opening and closing of the upper gripper, lower gripper, upper ring gripper, and lower ring gripper, and to control the rotation, flipping, and lifting movements of the robotic arm. The valve stem operation is a pure hydraulic operation mode, and the driller's cabin operation is divided into manual and automatic operation modes.

[0010] On the other hand, the present invention also provides a control method for a four-degree-of-freedom pipe-gripping robotic arm control system, including process control for drilling down and process control for drilling up. The process control for drilling down specifically includes the following steps: S1, Initialization; S2. The pipe-grabbing robotic arm descends to the pipe-grabbing position; S3, upper and lower ring holding rings are closed; S4. Lower clamping hand closed, upper clamping hand closed; S5. Move the upper and lower ring handles to the ring holding positions and wait for the next command. After manual confirmation, continue to automatically execute the subsequent steps. S6. The pipe-grabbing robotic arm moves upward; S7. After the pipe gripping robot arm moves up to the set height position one, it begins to rotate. At the same time, the pipe gripping robot arm continues to move up. When it rotates at the height position one, the pipe column and the ground support frame do not interfere with each other. S8. The pipe-grabbing robotic arm stops rotating after it reaches the vertical position. S9. The pipe gripping robot arm continues to move upward to the set height position two and then starts to rotate. After rotating to the waiting position, it stops. At the same time, the pipe gripping robot arm continues to move upward. When rotating at height position two, the pipe column and the moving pipeline do not interfere with each other. S10. The pipe-grabbing robotic arm continues to move upward to the set height position three and then stops moving upward. When the pipe-grabbing robotic arm at the height position three rotates with the pipe to the wellhead position, it does not interfere with the wellhead equipment. S11. The pipe-grabbing robotic arm rotates with the pipe to the wellhead position; S12. The manipulator arm descends with the pipe and engages with the wellhead tubing string. The specific steps involved in controlling the drilling process include: Q1. Initialization: Both gripping hands and both ring gripping hands are in the open state; Q2. The pipe-grabbing robotic arm moves upward; Q3. After the pipe-grabbing robotic arm moves up to the program-set height position one, it begins to rotate, while the pipe-grabbing robotic arm continues to move up. Q4. The pipe-grabbing robotic arm stops rotating after it reaches the vertical position. Q5. The pipe-grabbing robotic arm continues to move upward to the second height position set in the program and then starts to rotate. After rotating to the waiting position, it stops, and at the same time, the pipe-grabbing robotic arm continues to move upward. Q6. The pipe-grabbing robotic arm continues to move upwards to the third stop position set in the program and then stops moving upwards. After manual confirmation, it will continue to automatically execute the subsequent steps. Q7. Rotate the pipe-grabbing robotic arm to the wellhead position; Q8. The robotic arm grips the pipe string, the automatic hydraulic tongs extend and automatically uncouple, and after manual confirmation that the uncoupling is complete and the automatic hydraulic tongs have withdrawn from the wellhead position, the subsequent steps are executed automatically. Q9. The upper and lower grippers of the pipe-grabbing robotic arm are closed; Q10. The upper and lower grippers of the robotic arm are closed; Q11. The pipe-grabbing robotic arm moves the pipe upwards, confirming that the male end of the pipe column has disengaged from the coupling. Q12. The pipe-grabbing robotic arm rotates and repositions the pipe; Q13. The pipe-grabbing robotic arm descends with the pipe to the pipe-grabbing position; Q14. The two ring grippers of the pipe gripping robotic arm hold the pipe column; Q15. The two gripping hands and two ring gripping hands on the robotic arm are open; Q16. The manipulator arm moves up to the waiting position, waiting for the next drilling process.

[0011] Preferably, when initializing the operation, it is determined whether the following optimal state is being maintained: S101. If the robotic arm is in the wellhead position, the robotic arm initialization program is triggered, and it automatically rotates to the pipe row position. S102. If the robotic arm is in a vertical position, the robotic arm initialization program is triggered, and it automatically flips to a horizontal position. S103. If the gripper is not open, the robotic arm initialization program is triggered, and the gripper opens automatically. S104. If the pipe-gripping robot arm is not open, the robot arm initialization program will be triggered, and the upper and lower mechanical grippers will open automatically. S105. If the robotic arm does not reach the waiting position, the robotic arm initialization program is triggered, and the robotic arm automatically moves up or down to reach the waiting position.

[0012] Preferably, the precise control method for the robotic arm to rotate to the tube row position and flip to the horizontal position is as follows: S201. Based on the scale on the rotation stroke and the wellhead position, standby position and pipe row position detected by the three proximity switches respectively, a target position is given, which is the pipe row position under the initialization condition. S202. Compare the real-time value of the feedback rotary encoder with the target position scale value or detect whether the tube row position has been reached. S203. Automatically adjust the comparison value using a PID algorithm; S204. The control value after PID adjustment is calculated by the amplifier PWMI and then output to the hydraulic solenoid proportional valve. S205. The proportional valve controls the rotation mechanism until it reaches the target position and then stops. The automatic control method for the tilting mechanism under initialization conditions is as follows: S301. Given a destination position, initialized as a horizontal position; S302. Compare the real-time displacement value with the target position scale value or detect whether the vertical position has been reached. S303. Automatically adjust the comparison value using a PID algorithm; S304. The control value after PID adjustment is calculated by the amplifier PWMI and then output to the hydraulic solenoid proportional valve. S305, the proportional valve controls the tilting mechanism to operate until it reaches the target position and then stops.

[0013] Preferably, before the pipe-grabbing robotic arm is initialized, a step for identifying and adjusting the pipe string is also included: T1. A guide rail is provided on the flip arm of the robotic arm along the length direction parallel to the flip arm. A drive module is installed on the guide rail, and a camera module is connected to the drive module. The drive module and the camera module are respectively connected to the main controller of the robotic arm body. The main controller of the robotic arm body is also connected to a calculation module. An adjustment cylinder is provided between the gripping robotic arm and the upper gripper. The adjustment cylinder is connected to the main controller of the robotic arm body and the distance between the upper gripper and the lower gripper is adjusted by the adjustment cylinder. T2. After the pipe-grabbing robotic arm grabs the pipe, it starts the drive module to move along the guide rail, and the camera module scans the pipe column along the length direction to obtain and record the initial contour information. T3. Before engaging the drill string with the trip ring, restart the drive module to move along the guide rail. The camera module scans the string along its length to acquire and record real-time contour information and set the contour data deviation. T4. Compare the real-time contour information with the initial contour information. If the deviation exceeds the contour data, adjust the distance between the upper gripper and the lower gripper through the main controller of the robotic arm body to avoid the position where the outer diameter changes too much after the pipe column is operated. T5. After adjusting the upper clamping hand to a position that meets the profile data deviation, continue to hold the tubing column.

[0014] The present invention has at least the following beneficial effects: (1) The four-degree-of-freedom pipe-grabbing robotic arm control system and its control method of the present invention use a four-degree-of-freedom pipe-grabbing robotic arm to replace manual operation, reduce the number of workers on the high-level platform by 3, realize unmanned operation of pipe column conveying on the high-level work platform, and improve the safety of workers.

[0015] (2) The four-degree-of-freedom pipe-grabbing manipulator control system and its control method of the present invention have the functions of gripping, clamping, moving up and down, flipping and rotating, precise positioning, automatic cruising, and automatic coupling at the wellhead. The four-degree-of-freedom pipe-grabbing manipulator has high precision, reduces manual intervention, and improves efficiency by 20% compared with the manual operation mode.

[0016] (3) The four-degree-of-freedom manipulator control system and its control method of the present invention are equipped with a remote operation terminal in the driller's room and a main controller of the manipulator body. The integrated control in the driller's room can control each degree of freedom of the manipulator body through the main controller of the manipulator body, or it can be embedded in the automatic tripping and jacking operation process for "one-click" control.

[0017] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the four-degree-of-freedom pipe-grabbing robotic arm provided by the present invention; Figure 2 The structural block diagram of the control system provided by the present invention; Figure 3 This is a flowchart illustrating the process of controlling the robotic arm during drilling according to the present invention. Figure 4 This is a flowchart of the initialization process for the four-degree-of-freedom pipe-grabbing robotic arm of the present invention. Figure 5 A flowchart of the control method for automatic rotation of a robotic arm provided by the present invention; Figure 6 A flowchart of the control method for automatic flipping of a robotic arm provided by the present invention; Figure 7 The flowchart for controlling the robotic arm during the drilling process provided by this invention.

[0019] Instruction manual illustrations and reference numerals: 1. Ring gripper; 2. Clamping gripper; 3. Tilting arm; 4. Rotating arm; 5. Control box; A. Driller's cabin; B. Pipe gripping robotic arm; A-1. Driller's cabin remote operation terminal; A-2. Touch screen one; A-3. Touch screen two; A-4. Operating components; B-1. Main controller of robotic arm body; B-2. Remote controller; B-3. Amplifier; B-4. Multi-valve manifold; B-5. Safety barrier one; B-6. Proximity switches 1~8; B-7. Safety barrier two; B-8. Magnetostrictive displacement sensors 1~5; B-9. Encoder one; Encoder two. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0021] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified. In the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] like Figure 1-7As shown, this invention provides a four-degree-of-freedom pipe-grabbing manipulator control system, including a main controller B-1, an amplifier B-3, a multi-valve assembly B-4, a safety barrier, multiple proximity switches, multiple safety isolation barriers (B-5, B-7), a displacement sensor, encoder one, encoder two B-9, and a remote operation terminal A-4, used to control the operation of the pipe-grabbing manipulator B. The pipe-grabbing manipulator B is equipped with a pipe-grabbing arm control box 5, a hydraulic valve island box, a vertical pipe-grabbing mechanism, a rotating mechanism, a gear and rack lifting mechanism, and a tilting mechanism. The main controller B-1 is located inside the pipe-grabbing arm control box 5 and communicates with the remote operation terminal. The multi-valve assembly B-4 is installed on the hydraulic valve island box. The main controller B-1 contains a high-precision counting module and an analog input module. Encoder one is installed on the rotating mechanism, and encoder two is installed on the gear and rack lifting mechanism. The main controller B-1 controls the operation of the pipe-grabbing manipulator B via a high-precision counting module. The main controller B-1 is connected to encoder 1 for real-time positioning and acquisition of the robotic arm's rotation position signal to accurately locate the robotic arm's rotation position. The main controller B-1 of the robotic arm body is connected to encoder 2 through a high-precision counting module for real-time positioning and acquisition of the height signal of the robotic arm's rack and pinion lifting mechanism to accurately locate the robotic arm's height position. The main controller B-1 of the robotic arm body is connected to the flipping mechanism through an analog input module for real-time positioning and acquisition of the robotic arm's flipping angle signal to accurately locate the robotic arm's flipping angle. The main controller B-1 of the robotic arm body is connected to multi-valve group B-4 through amplifier B-3. Multi-valve group B-4 is a multi-way proportional valve to realize proportional control of the valve. The main controller B-1 of the robotic arm body is connected to proximity switches through safety isolation barriers. The proximity switches have proximity sensors, and the status signals collected by the proximity switches include the robotic arm's rotation position, gripper with tube, and gripper without tube status signals.

[0023] The pipe-grabbing robotic arm B rises and falls along a vertical column, driven by a lifting motor via a rack and pinion mechanism. A rotating arm 4 is mounted on the rack and pinion structure and connected to a rotating frame. A control box 5 is mounted on the rotating frame, and a tilting arm 3 is connected to the outer end of the rotating frame. Upper and lower grippers 2 and upper and lower ring grippers 1 are respectively connected to the two ends of the tilting arm 3. In the vertical state, the grippers 2 and ring grippers 1 are positioned one up and one down, and in the horizontal state, they are positioned one left and one right. Some of the mechanisms have been disclosed and will not be described further here. The tilting mechanism is a tilting cylinder, and the rotating mechanism is a rotating motor. The control system of the four-degree-of-freedom pipe-grabbing robotic arm B of this invention is based on the pipe-grabbing machine... On robotic arm B, corresponding control and acquisition of the up-and-down movement, rotation, flipping, and gripping of the four-degree-of-freedom pipe-grabbing robotic arm B and corresponding feedback data are provided. Proximity switches are set for the robotic arm's rotation position, gripper with pipe, and gripper without pipe, so that the four-degree-of-freedom pipe-grabbing robotic arm B has the functions of gripping, clamping, moving up and down, flipping, and rotating. It can accurately position and automatically cruise, realizing unmanned pipe delivery operations on the high-level work platform, replacing manual operation, reducing the number of personnel working on the high-level platform by 3, and the automatic coupling accuracy at the wellhead is high, reducing manual intervention and improving efficiency by 20% compared to the manual operation mode.

[0024] In another technical solution, such as Figure 1 , 3 As shown in Figure 7, the rotating mechanism is provided with three rotating positions: the waiting position, the pipe row position, and the wellhead position. Each rotating position is provided with a proximity switch. The main controller B-1 of the robotic arm body is connected to the three proximity switches of the rotating mechanism through a safety isolation fence to achieve precise point positioning and position protection of the rotating mechanism at the three positions.

[0025] The waiting position is usually set higher than the pipe string position, in a standby waiting state, to avoid interfering with the pipe string laying and pipe laying machine operation below. Then, according to the instruction, the pipe is moved down to retrieve the pipe or moved up and flipped to connect to the wellhead position for drilling.

[0026] In another technical solution, such as Figure 1-3 As shown in Figure 7, the flipping mechanism has a built-in magnetostrictive displacement sensor B-8 to collect displacement signals. The main controller B-1 of the robotic arm body is connected to the magnetostrictive displacement sensor B-8 for precise positioning of the robotic arm's flipping angle. The flipping mechanism has two corresponding flipping points, corresponding to the fully horizontal and vertical states. Each flipping point is equipped with a proximity switch. The main controller B-1 of the robotic arm body is connected to the two proximity switches of the flipping mechanism through another safety barrier to achieve precise positioning and position protection of the flipping mechanism in horizontal and vertical positions. The horizontal state is used to grasp the tubing string and drive it upward a certain distance, while the vertical state is used to drive the tubing string to rotate horizontally and dock with the wellhead tubing string.

[0027] In another technical solution, such as Figure 1-7 As shown, the upper and lower mechanical pipe gripping mechanism includes an upper ring gripper 1, a lower ring gripper 1, an upper clamping hand 2, a lower clamping hand 2, a floating mechanism for the lower clamping hand 2, a ring gripping and clamping opening / closing position detection sensor, a pipe string presence / absence detection sensor for the ring gripper 1, and a floating limit detection sensor for the lower clamping hand 2. These respectively realize the ring gripping and centering function of the pipe string, the pipe string clamping function of the upper and lower mechanical hands, and the wellhead downlink connection function. The ring gripping and clamping opening / closing position detection sensor detects whether the ring gripper 1 and clamping hand 2 are open or closed. The pipe string presence / absence detection sensor detects whether there is pipe string inside the two ring grippers 1. The lower clamping hand 2 has a floating distance for flexible connection. When the pipe string posture is adjusted and determined to be completely parallel to the clamping axes of the two clamping hands 2, it is first clamped in the floating section and then fully clamped. The floating limit detection sensor for the lower clamping hand 2 detects whether the floating section is in place and whether the clamping hand 2 is fully clamped.

[0028] In another technical solution, such as Figure 1-7 As shown, the control system of the pipe-grabbing robotic arm B has three operating modes: valve stem, remote controller B-2, and driller's cabin A. Driller's cabin A includes an integrated remote operation terminal A-1 and touch screens A-2, A-3, and A-4, which are respectively connected to the remote operation terminal A-1. The remote controller B-2 is connected to the main controller B-1 of the robotic arm body and is in manual operation mode. It is used to remotely send control commands and receive data signals. As the control unit of the pipe-grabbing robotic arm B body, it controls the opening and closing of the upper gripper 2, lower gripper 2, upper ring gripper 1, and lower ring gripper 1, and controls the rotation, flipping, and lifting actions of the robotic arm. The valve stem operation is a pure hydraulic operation mode. The operation of driller's cabin A is divided into manual and automatic operation modes. The main controller B-1 of the robotic arm and the remote operation terminal are PLC control systems. The main controller is connected to the main controller B-1 of the robotic arm via a PN bus to realize multi-mode operation of the robotic arm, reduce the number of personnel working on the ground and high-level platform, and ensure the safety of the personnel. By detecting the status data of the robotic arm through various sensors, the unmanned transportation of the tubing from the ground to the wellhead of the high-level platform is realized.

[0029] The control system in this embodiment includes an integrated control unit for the driller's cabin A and a main control unit for the pipe-grabbing robotic arm B. These two units are connected via a communication line. In the integrated control unit for the driller's cabin A, touchscreen A-2, touchscreen A-3, and operating components A-4 are connected to the remote operation terminal A-1 of the integrated control system for the driller's cabin. In the main control unit for the pipe-grabbing robotic arm B, remote controller B-2 is connected to the main controller B-1 of the robotic arm. The main controller B-1 is connected to the multi-valve assembly B-4 via amplifier B-3 to control the valve movements. Device B-1 is connected to proximity switches (1~8) and B-6 via safety barriers (1~2) and B-5 respectively to acquire multiple position status signals. The main controller of the robotic arm body is connected to the magnetostrictive displacement sensors (1~5) and B-8 of the gripper 2 mechanism, the ring gripper 1 mechanism, and the flipping mechanism via safety barriers (1~2) and B-7 respectively to achieve precise positioning of the gripper position, ring gripping state, and flipping arm 3 mechanism at different positions. The main controller is connected to the rotating arm 4 mechanism, encoder 1, and encoder 2 (B-9) to achieve precise positioning of the rotating mechanism angle and the vertical column height.

[0030] The pipe-grabbing robotic arm B is controlled via three operating modes: a multi-way valve stem, remote controller B-2, and driller's cabin A. The valve stem operation is purely hydraulic and is used only for debugging purposes. Remote controller B-2 is manual operation without any logic protection and is for emergency use. Driller's cabin A operation has both manual and automatic modes.

[0031] The proximity switch signal sources include proximity switches for detecting the presence or absence of pipe in the ring gripper 1, the position of the rotating arm 4 in the pipe row, waiting position, and wellhead position, the horizontal and vertical position of the tilting arm 3, and the floating limit of the lower gripper 2, thus realizing the detection of each position. The displacement detection sensors for the tilting arm 3 cylinder, the ring gripper 1 cylinder, and the gripper 2 cylinder are built-in magnetostrictive displacement sensors B-8, which realize the stroke detection of the cylinder. Encoder 1 is installed on the shaft end of the rotary mechanism to realize the detection of the rotation angle; encoder 2 is installed on the shaft end of the trolley lifting motor to realize the detection of the height position of the robotic arm trolley at the vertical column.

[0032] This invention also provides a control method for the control system of a four-degree-of-freedom pipe-grabbing robotic arm B, combined with Figure 1-7 As shown, this includes process control for drilling down and process control for tripping out, such as... Figure 3 As shown, the process control for drilling includes the following steps: S1. Initialize the pipe-grabbing robotic arm B; S2. The pipe-grabbing robotic arm B descends to the pipe-grabbing position; S3, Upper ring handle 1, Lower ring handle 1 ring closed; S4. Lower clamping hand 2 is closed, upper clamping hand 2 is closed; S5. Upper ring handle 1 and lower ring handle 1 move to the ring holding position, wait for the next command, and continue to automatically execute the subsequent steps after manual confirmation; S6. The pipe-grabbing robotic arm B moves upward; S7. After the pipe gripping robot arm B moves up to the set height position one, it begins to rotate. At the same time, the pipe gripping robot arm B continues to move up. When it rotates at the height position one, the pipe column and the ground support frame do not interfere with each other. S8. The pipe-grabbing robotic arm B stops rotating after it reaches the vertical position. S9. The pipe gripping robot arm B continues to move upward to the set height position two and then starts to rotate. After rotating to the waiting position, it stops. At the same time, the pipe gripping robot arm B continues to move upward. When rotating at the height position two, the pipe column and the moving pipeline do not interfere with each other. S10. The pipe-grabbing robotic arm B continues to move upward to the set height position three and then stops moving upward. When the pipe-grabbing robotic arm B rotates with the pipe to the wellhead position at the height position three, it does not interfere with the wellhead equipment. S11. The pipe-grabbing robotic arm B rotates with the pipe to the wellhead position; S12, the pipe-grabbing robotic arm B descends with the pipe and engages with the wellhead tubing string; like Figure 7 As shown, the specific steps involved in controlling the drilling process include the following: Q1. Initialization: Both gripping hands 2 and both ring gripping hands 1 are in the open state; Q2. The pipe-grabbing robotic arm B moves upward; Q3. After the pipe-grabbing robotic arm B moves up to the program-set height position one, it begins to rotate, and at the same time, the pipe-grabbing robotic arm B continues to move up. Q4. The pipe-grabbing robotic arm B stops rotating after it reaches the vertical position. Q5. After the pipe gripping robot arm B continues to move upward to the second height position set in the program, it starts to rotate. After rotating to the waiting position, it stops, and at the same time, the pipe gripping robot arm B continues to move upward. Q6. The pipe-grabbing robotic arm B continues to move upwards to the third stop position set in the program and then stops moving upwards. After manual confirmation, it will continue to automatically execute the subsequent steps. Q7. Rotate the pipe gripping robot arm B to the wellhead position (after initialization, both the robot arm gripper and the ring gripper 1 are in the open state). Q8. The pipe gripping robotic arm B ring holder 1 ring holds the pipe string, the automatic hydraulic tongs extend and automatically uncouple, and after manual confirmation that the uncoupling is completed and the automatic hydraulic tongs have withdrawn from the wellhead position, the subsequent steps are automatically executed. Q9. The upper and lower ring grippers of the pipe gripping robotic arm B are closed. Q10. Close the upper gripper 2 and lower gripper 2 of the robotic arm; Q11. The pipe-grabbing robotic arm B moves the pipe upwards by 50mm, confirming that the male end of the pipe column has disengaged from the coupling. Q12. Pipe-grabbing robotic arm B rotates and repositions the pipe; Q13. The pipe-grabbing robotic arm B descends with the pipe to the pipe-grabbing position; Q14. Pipe gripping robotic arm B has two ring grippers and one ring gripper for holding the pipe column; Q15. The two gripping hands 2 on the robotic arm are open, and the two ring gripping hands 1 are open; Q16. The pipe-grabbing robotic arm B moves up to the waiting position, waiting for the next drilling process.

[0033] In another technical solution, such as Figure 4 As shown, the initialization process ensures that the system is in the optimal state as follows: S101. If the robotic arm is in the wellhead position, the robotic arm initialization program is triggered, and it automatically rotates to the pipe row position. S102. If the robotic arm is in a vertical position, the robotic arm initialization program is triggered, and it automatically flips to a horizontal position. S103. If the ring gripper 1 is not open, the robotic arm initialization program is triggered, and the ring gripper 1 opens automatically. S104. If the pipe-gripping robot arm is not open, the robot arm initialization program will be triggered, and the upper and lower mechanical grippers will open automatically. S105. If the robotic arm does not reach the waiting position, the robotic arm initialization program is triggered, and the robotic arm automatically moves up or down to reach the waiting position.

[0034] In another technical solution, such as Figure 5-6 As shown, the programs for rotating the robotic arm to the tube row position (S2) and flipping it to the horizontal position (S3) achieve precise control of the position to the waiting position. The automatic rotation (S2) program achieves automatic control of the rotary motor's movement under initialization conditions. The precise control methods for rotating the robotic arm to the tube row position and flipping it to the horizontal position are as follows: S201. Based on the scale on the rotation stroke and the wellhead position, standby position and pipe row position detected by the three proximity switches respectively, a target position is given, which is the pipe row position under the initialization condition. S202. Compare the real-time value of the feedback rotary encoder with the target position scale value or detect whether the tube row position has been reached. S203. Automatically adjust the comparison value using a PID algorithm (automatic adjustment of P, I, and D parameters); S204. The control value after PID adjustment is calculated by amplifier B-3PWMI and output to the hydraulic solenoid proportional valve. S205. The proportional valve controls the rotation mechanism until it reaches the target position and then stops. The automatic tilting (S3) program automatically controls the tilting cylinder's movement under initialization conditions. The automatic control method for the tilting mechanism's movement under initialization conditions is as follows: S301. Given a destination position, initialized as a horizontal position; S302. Compare the real-time displacement value with the target position scale value or detect whether the vertical position has been reached. S303. Automatically adjust the comparison value using a PID algorithm (automatic adjustment of P, I, and D parameters); The control value after S304 and PID adjustment is calculated by amplifier B-3PWMI and then output to the hydraulic solenoid proportional valve. S305, the proportional valve controls the tilting mechanism to operate until it reaches the target position and then stops.

[0035] By performing PID negative feedback calculations and PWMI strategy control on the tilting cylinder and rotary motor, the precise control of the tilting mechanism at the two target positions (vertical and horizontal) and the rotary mechanism at the three target positions (waiting position, pipe row position, and wellhead position) on the scale is ensured. The positioning is accurate and error-free, which guarantees the accuracy of the robotic arm's downward connection at the wellhead and the reliability of the pipe row position for gripping the pipe.

[0036] In another technical solution, such as Figure 1 As shown, before the initialization of the pipe-grabbing robotic arm B, there is also a step of identifying and adjusting the pipe column: T1. A guide rail is provided on the flipping arm 3 of the robotic arm along the length direction parallel to the flipping arm 3. A drive module is installed on the guide rail, and a camera module is connected to the drive module. The drive module and the camera module are respectively connected to the main controller B-1 of the robotic arm body. The main controller B-1 of the robotic arm body is also connected to a calculation module. An adjustment cylinder is provided between the gripping robotic arm B and the upper gripper 2. The adjustment cylinder is connected to the main controller B-1 of the robotic arm body. The distance between the upper gripper 2 and the lower gripper 2 is adjusted by the adjustment cylinder. T2. After the pipe-grabbing robotic arm B grabs the pipe, the drive module is activated to move along the guide rail, and the camera module scans the pipe column along its length to acquire and record the initial contour information. T3. Before engaging the drill string with the trip ring, restart the drive module to move along the guide rail. The camera module scans the string along its length to acquire and record real-time contour information and set the contour data deviation. T4. Compare the real-time contour information with the initial contour information. If the deviation exceeds the contour data, adjust the distance between the upper gripper 2 and the lower gripper 2 through the main controller B-1 of the robotic arm body to avoid the position where the outer diameter changes too much after the operation of the pipe column. T5. After the upper clamping hand 2 is adjusted to a position that meets the deviation of the contour data, it continues to hold the column.

[0037] To address the issue of contamination on the outer wall of the tubing after tripping, which can affect clamping stability and cleanliness, a camera module is installed to scan the tubing as it is gripped by the tubing machine. This scan serves as the initial comparison of contour parameters. Before unclamping, the camera scans the exposed outer wall of the tubing and adjusts the vertical position of the robotic arm relative to the tubing to select a better clamping position. Specifically, the vertical clamping hands 2 and 1 are positioned such that the lower clamping hands 2 and 1 serve as the main clamping support, while the upper clamping hands 2 and 1 can be further adjusted to maintain their distance from the lower clamping hand 2. This allows for better selection of the appropriate position on the outer wall of the tubing and ensures the balance and stability of the tubing clamping.

[0038] The four-degree-of-freedom pipe-grabbing manipulator control system and its control method of the present invention include a manipulator body control section and a driller's cab control section. The manipulator body control section is equipped with a corresponding main controller. Encoders and proximity switches are respectively set for the gripping, lifting, rotating and flipping of the manipulator. Signals are collected through a high-precision counting module and an analog input module to achieve precise motion control of the manipulator, realizing accurate positioning of the manipulator's height, rotation position and flipping angle. The driller's cab control section is set up to centrally observe and control in multiple modes through a remote operation terminal. In the process of automated live-line operation, the four-degree-of-freedom pipe-grabbing manipulator replaces the traditional hoist and hydraulic winch for conveying pipe columns, freeing operators from heavy physical labor and the safety risks of operating on high-level platforms. With the help of various interlocking protections, the safety of the equipment is absolutely guaranteed.

[0039] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A four-degree-of-freedom pipe-grabbing robotic arm control system, characterized in that, The system includes a main controller for the robotic arm, an amplifier, a multi-valve assembly, safety barriers, multiple proximity switches, multiple safety isolation barriers, displacement sensors, encoder one, encoder two, and a remote operating terminal. This system controls the operation of the pipe-grabbing robotic arm. The robotic arm is equipped with a pipe-grabbing arm control box, a hydraulic valve island box, a lifting and lowering mechanical pipe-grabbing mechanism, a rotating mechanism, a gear and rack lifting mechanism, and a tilting mechanism. The main controller is located inside the pipe-grabbing arm control box and communicates with the remote operating terminal. The multi-valve assembly is mounted on the hydraulic valve island box. The main controller contains a high-precision counting module and an analog input module. Encoder one is mounted on the rotating mechanism, and encoder two is mounted on the gear and rack lifting mechanism. The main controller of the robot arm is connected to encoder one via a high-precision counting module for real-time positioning and acquisition of the robot arm's rotation position signal. The main controller of the robot arm is connected to encoder two via a high-precision counting module for real-time positioning and acquisition of the height signal of the robot arm's gear and rack lifting mechanism. The main controller of the robot arm is connected to the flipping mechanism via an analog input module for real-time positioning and acquisition of the robot arm's flipping angle signal. The main controller of the robot arm is connected to a multi-valve group via an amplifier to achieve proportional control of the valves. The main controller of the robot arm is connected to proximity switches via safety isolation barriers. The proximity switches acquire status signals including the robot arm's rotation position, gripper with tube, and gripper without tube status signals.

2. The four-degree-of-freedom pipe-grabbing robotic arm control system as described in claim 1, characterized in that, The rotating mechanism is provided with three rotation points: a waiting position, a pipe row position, and a wellhead position. Each rotation point is provided with a proximity switch. The main controller of the robotic arm is connected to the three proximity switches of the rotating mechanism through a safety isolation fence to achieve precise point positioning and position protection of the rotating mechanism at the three positions.

3. The four-degree-of-freedom pipe-grabbing robotic arm control system as described in claim 1, characterized in that, The flipping mechanism has a built-in magnetostrictive displacement sensor to collect displacement signals. The main controller of the robotic arm is connected to the magnetostrictive displacement sensor for precise positioning of the flipping angle of the robotic arm. The flipping mechanism is provided with two flipping points, corresponding to the flipping mechanism being in a completely horizontal state and a vertical state. Each flipping point is provided with a proximity switch. The main controller of the robotic arm is connected to the two proximity switches of the flipping mechanism through another safety isolation fence to achieve precise positioning and position protection of the flipping mechanism in the horizontal and vertical positions.

4. The four-degree-of-freedom pipe-grabbing robotic arm control system as described in claim 3, characterized in that, The upper and lower mechanical pipe gripping mechanism includes an upper ring gripper, a lower ring gripper, an upper clamping hand, a lower clamping hand, a lower clamping hand floating mechanism, a ring gripping and clamping opening and closing position detection sensor, a ring gripper with or without pipe string detection sensor, and a lower clamping hand floating limit detection sensor, which respectively realize the ring gripping and centering function of the pipe string, the upper and lower mechanical gripper pipe string clamping function, and the wellhead downward connection function.

5. The four-degree-of-freedom pipe-grabbing robotic arm control system as described in claim 4, characterized in that, The control system of the pipe-grabbing robotic arm has three operating modes: valve stem, remote control, and driller's cabin. The driller's cabin includes an integrated remote operation terminal and two touch screens connected to the remote operation terminal, as well as operating components. The remote control is connected to the main controller of the robotic arm and is in manual operation mode. It is used to remotely send control commands and receive data signals. As the control unit of the pipe-grabbing robotic arm, it controls the opening and closing of the upper gripper, lower gripper, upper ring gripper, and lower ring gripper, and controls the rotation, flipping, and lifting movements of the robotic arm. The valve stem operation is a pure hydraulic operation mode. The driller's cabin operation is divided into manual and automatic operation modes.

6. The control method of the four-degree-of-freedom pipe-grabbing robotic arm control system as described in claim 5, characterized in that, This includes process control for drilling rig running and process control for tripping out of the hole. The specific steps for drilling rig running include: S1, Initialization; S2. The pipe-grabbing robotic arm descends to the pipe-grabbing position; S3, upper and lower ring holding rings are closed; S4. Lower clamping hand closed, upper clamping hand closed; S5. Move the upper and lower ring handles to the ring holding positions and wait for the next command. After manual confirmation, continue to automatically execute the subsequent steps. S6. The pipe-grabbing robotic arm moves upward; S7. After the pipe gripping robot arm moves up to the set height position one, it begins to rotate. At the same time, the pipe gripping robot arm continues to move up. When it rotates at the height position one, the pipe column and the ground support frame do not interfere with each other. S8. The pipe-grabbing robotic arm stops rotating after it reaches the vertical position. S9. The pipe gripping robot arm continues to move upward to the set height position two and then starts to rotate. After rotating to the waiting position, it stops. At the same time, the pipe gripping robot arm continues to move upward. When rotating at height position two, the pipe column and the moving pipeline do not interfere with each other. S10. The pipe-grabbing robotic arm continues to move upward to the set height position three and then stops moving upward. When the pipe-grabbing robotic arm at the height position three rotates with the pipe to the wellhead position, it does not interfere with the wellhead equipment. S11. The pipe-grabbing robotic arm rotates with the pipe to the wellhead position; S12. The manipulator arm descends with the pipe and engages with the wellhead tubing string. The specific steps involved in controlling the drilling process include: Q1. Initialization: Both gripping hands and both ring gripping hands are in the open state; Q2. The pipe-grabbing robotic arm moves upward; Q3. After the pipe-grabbing robotic arm moves up to the program-set height position one, it begins to rotate, while the pipe-grabbing robotic arm continues to move up. Q4. The pipe-grabbing robotic arm stops rotating after it reaches the vertical position. Q5. The pipe-grabbing robotic arm continues to move upward to the second height position set in the program and then starts to rotate. After rotating to the waiting position, it stops, and at the same time, the pipe-grabbing robotic arm continues to move upward. Q6. The pipe-grabbing robotic arm continues to move upwards to the third stop position set in the program and then stops moving upwards. After manual confirmation, it will continue to automatically execute the subsequent steps. Q7. Rotate the pipe-grabbing robotic arm to the wellhead position; Q8. The robotic arm grips the pipe string, the automatic hydraulic tongs extend and automatically uncouple, and after manual confirmation that the uncoupling is complete and the automatic hydraulic tongs have withdrawn from the wellhead position, the subsequent steps are executed automatically. Q9. The upper and lower grippers of the pipe-grabbing robotic arm are closed; Q10. The upper and lower grippers of the robotic arm are closed; Q11. The pipe-grabbing robotic arm moves the pipe upwards, confirming that the male end of the pipe column has disengaged from the coupling. Q12. The pipe-grabbing robotic arm rotates and repositions the pipe; Q13. The pipe-grabbing robotic arm descends with the pipe to the pipe-grabbing position; Q14. The two ring grippers of the pipe gripping robotic arm hold the pipe column; Q15. The two gripping hands and two ring gripping hands on the robotic arm are open; Q16. The manipulator arm moves up to the waiting position, waiting for the next drilling process.

7. The control method of the four-degree-of-freedom pipe-grabbing robotic arm control system as described in claim 6, characterized in that, When initializing and ensuring operations are performed, determine if the following optimal state is being maintained: S101. If the robotic arm is in the wellhead position, the robotic arm initialization program is triggered, and it automatically rotates to the pipe row position. S102. If the robotic arm is in a vertical position, the robotic arm initialization program is triggered, and it automatically flips to a horizontal position. S103. If the gripper is not open, the robotic arm initialization program is triggered, and the gripper opens automatically. S104. If the pipe-gripping robot arm is not open, the robot arm initialization program will be triggered, and the upper and lower mechanical grippers will open automatically. S105. If the robotic arm does not reach the waiting position, the robotic arm initialization program is triggered, and the robotic arm automatically moves up or down to reach the waiting position.

8. The control method of the four-degree-of-freedom pipe-grabbing robotic arm control system as described in claim 6, characterized in that, The precise control method for the robotic arm to rotate to the tube row position and flip to the horizontal position is as follows: S201. Based on the scale on the rotation stroke and the wellhead position, standby position and pipe row position detected by the three proximity switches respectively, a target position is given, which is the pipe row position under the initialization condition. S202. Compare the real-time value of the feedback rotary encoder with the target position scale value or detect whether the tube row position has been reached. S203. Automatically adjust the comparison value using a PID algorithm; S204. The control value after PID adjustment is calculated by the amplifier PWMI and then output to the hydraulic solenoid proportional valve. S205. The proportional valve controls the rotation mechanism until it reaches the target position and then stops. The automatic control method for the tilting mechanism under initialization conditions is as follows: S301. Given a target position, initialized as a horizontal position; S302. Compare the real-time displacement value with the target position scale value or detect whether the vertical position has been reached. S303. Automatically adjust the comparison value using a PID algorithm; S304. The control value after PID adjustment is calculated by the amplifier PWMI and then output to the hydraulic solenoid proportional valve. S305, the proportional valve controls the tilting mechanism to operate until it reaches the target position and then stops.

9. The control method of the four-degree-of-freedom pipe-grabbing robotic arm control system as described in claim 6, characterized in that, Before the pipe-grabbing robotic arm is initialized, the process also includes identifying and adjusting the pipe column: T1. A guide rail is provided on the flip arm of the robotic arm along the length direction parallel to the flip arm. A drive module is installed on the guide rail, and a camera module is connected to the drive module. The drive module and the camera module are respectively connected to the main controller of the robotic arm body. The main controller of the robotic arm body is also connected to a calculation module. An adjustment cylinder is provided between the gripping robotic arm and the upper gripper. The adjustment cylinder is connected to the main controller of the robotic arm body and the distance between the upper gripper and the lower gripper is adjusted by the adjustment cylinder. T2. After the pipe-grabbing robotic arm grabs the pipe, it starts the drive module to move along the guide rail, and the camera module scans the pipe column along the length direction to obtain and record the initial contour information. T3. Before engaging the drill string with the trip ring, restart the drive module to move along the guide rail. The camera module scans the string along its length to acquire and record real-time contour information and set the contour data deviation. T4. Compare the real-time contour information with the initial contour information. If the deviation exceeds the contour data, adjust the distance between the upper gripper and the lower gripper through the main controller of the robotic arm body to avoid the position where the outer diameter changes too much after the pipe column is operated. T5. After adjusting the upper clamping hand to a position that meets the profile data deviation, continue to hold the tubing column.

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