Pneumatic flexible clamping jaw grabbing system

Abstract

The invention relates to a pneumatic flexible clamping jaw grabbing system which solves the technical problems that an existing rigid clamping jaw is poor in adaptability, prone to causing damage to a target object and low in man-machine cooperation safety. The pneumatic flexible clamping jaw grabbing system comprises a frame, an XYZ three-axis linear module and a flexible clamping jaw, and the XYZ three-axis linear module is used for adjusting the position of the flexible clamping jaw; the flexible clamping jaw comprises a pneumatic flexible arm fixing plate, an air guide pipe, an air pipe adapter, an air feeding pipe, three pneumatic flexible arms and three air guide pipes, the three pneumatic flexible arms are connected with the pneumatic flexible arm fixing plate, the lower ends of the three air guide pipes are communicated with the three pneumatic flexible arms respectively, the air pipe adapter is provided with an air inlet and three air outlets, and the air feeding pipe is connected with the air pipe adapter. The upper ends of the three gas guide pipes are respectively connected with three gas outlets of the gas pipe adapter, and the gas feeding pipe is connected with a gas inlet of the gas pipe adapter; and the air pipe adapter is fixedly connected with the lower fixing plate and the lower fixing plate.

Description

Technical Field

[0001] The present invention relates to the technical field of robotic arm grasping, and more particularly to a pneumatic flexible gripper grasping system. Background Art

[0002] Traditional rigid robotic arms have high load-bearing capacity and control accuracy and are widely used in manufacturing, industrial production, medical rehabilitation and other fields. Traditional rigid grippers dominate in structured industrial scenarios due to their high stiffness, fast response and ultra-high precision; their metal or carbon fiber structures can carry loads from hundreds of kilograms to several tons, and servo motors or pneumatic drives enable millisecond-level actions with a repeat positioning accuracy that perfectly suits high-precision scenarios. In the fields of automotive manufacturing, 3C electronics assembly, heavy-load logistics and high-temperature injection molding, rigid grippers have become an irreplaceable cornerstone technology due to their long service life and stability.

[0003] However, the hard-contact structure of rigid grippers has significant drawbacks. First, they have insufficient adaptability, relying on preset trajectories and regular geometric objects, and custom fixtures are required for irregular targets. Second, they pose high safety risks. The local pressure of metal contact exceeds 10 MPa, and the breakage rate of fragile items reaches 10% - 30%. Moreover, the impact force during human-robot collaboration often exceeds the ISO safety limit, and additional protective devices are needed. Third, they have disadvantages in energy efficiency and cost. The energy consumption of the high-power drive system accounts for 15% - 25% of the production line, and the annual maintenance cost reaches 8% - 12% of the equipment value. Complex calibration further drags down efficiency. Summary of the Invention

[0004] The present invention aims to solve the problems of poor adaptability of existing rigid grippers, easy damage to target objects, and low safety in human-robot collaboration, and provides a pneumatic flexible gripper grasping system that optimizes rigid grippers and improves grasping safety and stability.

[0005] The present invention provides a pneumatic flexible gripper grasping system, which includes a frame, a first lead screw slide table module, a second lead screw slide table module, an X-axis guide rod, a Y-axis guide rod, a robotic arm and a flexible gripper. The first lead screw slide table module and the second lead screw slide table module are respectively connected to the frame;

[0006] The robotic arm includes a fixed fixture, a left servo motor, a left transmission gear, a left connecting rod, a right servo motor, a right transmission gear, a right connecting rod, an upper fixing plate, a front fixing plate, a rear fixing plate, a lower fixing plate and a lower fixing plate. The fixed fixture is fixedly connected to the upper fixing plate. The left servo motor and the right servo motor are respectively connected to the front fixing plate. The left transmission gear is provided with a rod portion and a tooth portion. The tooth portion of the left transmission gear is connected to the output end of the left servo motor. The right transmission gear is provided with a rod portion and a tooth portion. The tooth portion of the right transmission gear is connected to the output end of the right servo motor. The tooth portions of the left transmission gear and the right transmission gear are meshed; the upper end of the left connecting rod is rotatably connected to the rod portion of the left transmission gear, and the upper end of the right connecting rod is rotatably connected to the rod portion of the right transmission gear; the left connecting rod and the right connecting rod are symmetrically arranged, and the rod portion of the left transmission gear and the rod portion of the right transmission gear are symmetrically arranged;

[0007] The fixed fixture includes an upper part of the fixed fixture, a middle part of the fixed fixture, a lower part of the fixed fixture, a Y-axis guide rod linear bearing and an X-axis guide rod linear bearing. The middle part of the fixed fixture is fixedly connected to the lower part of the fixed fixture. The X-axis guide rod linear bearing is connected between the middle part of the fixed fixture and the lower part of the fixed fixture. The upper part of the fixed fixture is fixedly connected to the middle part of the fixed fixture. The Y-axis guide rod linear bearing is connected between the upper part of the fixed fixture and the middle part of the fixed fixture; the Y-axis guide rod passes through the Y-axis guide rod linear bearing, and the X-axis guide rod passes through the X-axis guide rod linear bearing; the first lead screw slide module is provided with a first slider and a second slider. One end of the X-axis guide rod is fixedly connected to the first slider, and the other end of the X-axis guide rod is fixedly connected to the second slider; the second lead screw slide module is provided with a first slider and a second slider. One end of the Y-axis guide rod is fixedly connected to the first slider, and the other end of the Y-axis guide rod is fixedly connected to the second slider;

[0008] The flexible gripper includes a pneumatic flexible arm fixing plate, a tracheal adapter, an air supply pipe, three pneumatic flexible arms and three air guide pipes. The three pneumatic flexible arms are connected to the pneumatic flexible arm fixing plate. The lower ends of the three air guide pipes are respectively communicated with the three pneumatic flexible arms. The tracheal adapter is provided with one gas inlet and three gas outlets. The upper ends of the three air guide pipes are respectively connected to the three gas outlets of the tracheal adapter. The air supply pipe is connected to the gas inlet of the tracheal adapter; the tracheal adapter is fixedly connected to the lower fixing plate and the lower fixing plate, and the tracheal adapter is located in the horizontal plane.

[0009] Preferably, the pneumatic flexible arm includes an inner body, a corrugated outer body and a Luer connector; several left corrugated portions are provided on the left side of the inner body, several right corrugated portions are provided on the right side of the inner body. The left corrugated portions and the right corrugated portions are arranged oppositely. The width of the inner body gradually decreases from its rear end to its front end;

[0010] The top of the corrugated outer body is provided with a gas channel, which is distributed along the length direction of the corrugated outer body. The corrugated outer body is provided with a number of arc-shaped corrugated parts, and the number of arc-shaped corrugated parts are arranged in a line along the length direction of the corrugated outer body. The angle between the arc-shaped corrugated part and the axis of the corrugated outer body is 90°. The corrugated outer body is provided with a number of semi-circular deformation air chambers, and the number of semi-circular deformation air chambers are arranged in a line along the length direction of the corrugated outer body. The angle between the semi-circular deformation air chamber and the axis of the corrugated outer body is 90°. The number of semi-circular deformation air chambers is the same as the number of arc-shaped corrugated parts, and one semi-circular deformation air chamber corresponds to one arc-shaped corrugated part. The semi-circular deformation air chambers extend downward from the top of the corrugated outer body to the arc-shaped corrugated parts, and a number of semi-circular deformation air chambers are all communicated with the gas channel; from the rear end to the front end of the corrugated outer body, the widths of a number of arc-shaped corrugated parts gradually become smaller, the thickness of the corrugated outer body gradually becomes smaller, the widths of a number of semi-circular deformation air chambers gradually become smaller, and the depths of a number of semi-circular deformation air chambers gradually become smaller;

[0011] The Luer connector is connected to the rear end of the corrugated outer body, and the Luer connector is communicated with the gas channel;

[0012] The inner body is connected to the top of the corrugated outer body. The left corrugated part of the inner body corresponds to the left side of the arc-shaped corrugated part of the corrugated outer body, and the right corrugated part corresponds to the right side of the arc-shaped corrugated part of the corrugated outer body;

[0013] The material of the inner body is a flexible material, and the material of the corrugated outer body is a flexible material;

[0014] The Luer connector of the pneumatic flexible arm is connected to the lower end of the air duct.

[0015] Preferably, from the rear end to the front end of the corrugated outer body, the width of the gas channel gradually becomes larger.

[0016] Preferably, the inner body and the top of the corrugated outer body are connected by an integral molding method.

[0017] Preferably, three pneumatic flexible arms are evenly distributed along the circumferential direction.

[0018] The present invention also provides a pneumatic flexible gripper grasping system, including a frame, a first lead screw slide module, a second lead screw slide module, an X-axis guide rod, a Y-axis guide rod, a robotic arm and a flexible gripper. The first lead screw slide module and the second lead screw slide module are respectively connected to the frame;

[0019] The robotic arm includes a fixed fixture, a left servo motor, a left transmission gear, a left connecting rod, a right servo motor, a right transmission gear, a right connecting rod, an upper fixing plate, a front fixing plate, a rear fixing plate, a lower fixing plate and a lower fixing plate. The fixed fixture is fixedly connected to the upper fixing plate. The left servo motor and the right servo motor are respectively connected to the front fixing plate. The left transmission gear has a rod portion and a tooth portion. The tooth portion of the left transmission gear is connected to the output end of the left servo motor. The right transmission gear has a rod portion and a tooth portion. The tooth portion of the right transmission gear is connected to the output end of the right servo motor. The tooth portions of the left transmission gear and the right transmission gear are meshed; the upper end of the left connecting rod is rotatably connected to the rod portion of the left transmission gear, and the upper end of the right connecting rod is rotatably connected to the rod portion of the right transmission gear; the left connecting rod and the right connecting rod are symmetrically arranged, and the rod portions of the left transmission gear and the right transmission gear are symmetrically arranged;

[0020] The fixed fixture includes an upper part of the fixed fixture, a middle part of the fixed fixture, a lower part of the fixed fixture, a Y-axis guide rod linear bearing and an X-axis guide rod linear bearing. The middle part of the fixed fixture is fixedly connected to the lower part of the fixed fixture. The X-axis guide rod linear bearing is connected between the middle part of the fixed fixture and the lower part of the fixed fixture. The upper part of the fixed fixture is fixedly connected to the middle part of the fixed fixture. The Y-axis guide rod linear bearing is connected between the upper part of the fixed fixture and the middle part of the fixed fixture; the Y-axis guide rod passes through the Y-axis guide rod linear bearing, and the X-axis guide rod passes through the X-axis guide rod linear bearing; the first lead screw slide module is provided with a first slider and a second slider. One end of the X-axis guide rod is fixedly connected to the first slider, and the other end of the X-axis guide rod is fixedly connected to the second slider; the second lead screw slide module is provided with a first slider and a second slider. One end of the Y-axis guide rod is fixedly connected to the first slider, and the other end of the Y-axis guide rod is fixedly connected to the second slider;

[0021] The flexible gripper includes a pneumatic flexible arm fixing plate, three pneumatic flexible arms and three air ducts. The three pneumatic flexible arms are connected to the pneumatic flexible arm fixing plate. The lower ends of the three air ducts are respectively communicated with the three pneumatic flexible arms. The pneumatic flexible arm fixing plate is fixedly connected to the lower fixing plate and the lower fixing plate. The air pipe adapter is located in the horizontal plane;

[0022] The pneumatic flexible arm includes an inner body, a corrugated outer body and a luer connector; several left corrugated parts are provided on the left side of the inner body, several right corrugated parts are provided on the right side of the inner body. The left corrugated parts and the right corrugated parts are arranged oppositely. The width of the inner body gradually becomes smaller from its rear end to its front end;

[0023] The top of the corrugated outer body is provided with a gas channel, which is distributed along the length direction of the corrugated outer body. The corrugated outer body is provided with a number of arc-shaped corrugated parts, and the number of arc-shaped corrugated parts are arranged in a line along the length direction of the corrugated outer body. The angle between the arc-shaped corrugated part and the axis of the corrugated outer body is 90°. The corrugated outer body is provided with a number of semi-circular deformation air chambers, and the number of semi-circular deformation air chambers are arranged in a line along the length direction of the corrugated outer body. The angle between the semi-circular deformation air chamber and the axis of the corrugated outer body is 90°. The number of semi-circular deformation air chambers is the same as the number of arc-shaped corrugated parts, and one semi-circular deformation air chamber corresponds to one arc-shaped corrugated part. The semi-circular deformation air chamber extends downward from the top of the corrugated outer body to the arc-shaped corrugated part, and a number of semi-circular deformation air chambers are all communicated with the gas channel; from the rear end to the front end of the corrugated outer body, the widths of a number of arc-shaped corrugated parts gradually become smaller, the thickness of the corrugated outer body gradually becomes smaller, the widths of a number of semi-circular deformation air chambers gradually become smaller, and the depths of a number of semi-circular deformation air chambers gradually become smaller;

[0024] The Luer connector is connected to the rear end of the corrugated outer body, and the Luer connector is communicated with the gas channel;

[0025] The inner body is connected to the top of the corrugated outer body. The left corrugated part of the inner body corresponds to the left side of the arc-shaped corrugated part of the corrugated outer body, and the right corrugated part corresponds to the right side of the arc-shaped corrugated part of the corrugated outer body;

[0026] The material of the inner body is a flexible material, and the material of the corrugated outer body is a flexible material;

[0027] The Luer connector of the pneumatic flexible arm is connected to the lower end of the air duct;

[0028] The method for controlling three pneumatic flexible arms to grasp a target object includes the following steps:

[0029] The first step is to respectively denote the three pneumatic flexible arms as pneumatic flexible arm A1, A2, and A3; perform target object size modeling and shape curvature extraction;

[0030] Collect the image data of the target object through the vision module, extract the three-dimensional boundary dimensions of the target object, and set its length, width, and height to be L, W, and H respectively. From this, the equivalent volume of the object can be calculated:

[0031] V = L·W·H (5)

[0032] Further construct an equivalent covering sphere model to estimate the average surface curvature, and define the equivalent curvature radius as:

[0033]

[0034] Construct the average principal curvature

[0035]

[0036] Step 2: Target curvature back-calculation and target pressure calculation;

[0037] The pneumatic flexible arm bends and deforms after being pressurized, and its end attitude is characterized by its bending angle θ i The wrapping curvature κ of the target object * is set as: where ∈ is the grasping safety redundancy term; define the length of each pneumatic flexible arm as L0, and the corresponding attitude bending angle is θ i = κ * ·L0; Let the attitude angles of the three pneumatic flexible arms form an attitude vector Combined with the size and shape of the target object, generate the target attitude vector: To achieve this target attitude; there is the following non-linear mapping relationship between the air pressure applied to the pneumatic flexible arm and the attitude angle: θ i (t) = a1P i 3 (t) + a2P i 2 (t) + a3P i (t) + a4, according to the target attitude, back-calculate the required target air pressure P id = f -1 (θ i ), calculate the target pressure vector of the three pneumatic flexible arms: P d (t) = [P 1d (t), P 2d (t), P 3d (t)] T , and this result will be used as the target reference input for pneumatic control and enter the next closed-loop regulation stage;

[0038] Step 3: Attitude-guided closed-loop air pressure control strategy;

[0039] Define the system state variable as: P(t) = [P1(t), P2(t), P3(t)] T , the control input is the gas volume flow rate vector: φ(t) = [φ1(t), φ2(t), φ3(t)] T , the system dynamics is: where f(·) represents the pneumatic non-linear change term, B is the gas path flow-pressure coefficient matrix, construct the following PID controller for closed-loop air pressure regulation, and the control rate is:

[0040]

[0041] where the error term is defined as: e i (t) = P id (t) - P i (t).

[0042] The present invention also provides a pneumatic flexible gripper grasping system, including a frame 100, an XYZ three-axis linear module, and a flexible gripper 400. The XYZ three-axis linear module is connected to the frame and is used to adjust the position of the flexible gripper 400; the flexible gripper 400 includes a pneumatic flexible arm fixing plate 402, a trachea 403, a trachea adapter 404, an air supply pipe 405, three pneumatic flexible arms 401, and three tracheas 403. The three pneumatic flexible arms 401 are connected to the pneumatic flexible arm fixing plate 402, and the lower ends of the three tracheas 403 are respectively connected to the three pneumatic flexible arms 401 in communication. The trachea adapter 404 is provided with one gas inlet and three gas outlets. The upper ends of the three tracheas 403 are respectively connected to the three gas outlets of the trachea adapter 404, and the air supply pipe 405 is connected to the gas inlet of the trachea adapter 404; the trachea adapter 404 is fixedly connected to the lower fixing plate 311 and the lower fixing plate 312; the trachea adapter 404 is located in the horizontal plane.

[0043] The beneficial effects of the present invention are that, compared with traditional rigid grippers, this system has high environmental adaptability and object compatibility, can realize the grasping of objects with different shapes and various postures, and at the same time provides safer human-machine interaction and low-damage operation. The grasping effect is better, and accurate and safe grasping is achieved.

[0044] The flexible gripper has a fast response speed, strong load capacity, and better airtightness.

[0045] The structure of the semi-circular deformation air chamber not only makes the inflow of gas smoother, and the gas can fill the entire cavity faster, thus achieving a faster response speed; the widths of several arc-shaped corrugated parts gradually decrease, the widths of several semi-circular deformation air chambers gradually decrease, the depths of several semi-circular deformation air chambers gradually decrease, and the thickness of the corrugated outer body gradually decreases. Such an air path design from wide to narrow can make the gas flow into each cavity more quickly and evenly, make the gas fill each semi-circular deformation air chamber faster, and further improve the response speed of the robotic arm and the motion stability, meeting better control requirements.

[0046] The further features and aspects of the present invention will be clearly described in the following description of the specific embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is an axonometric view of the pneumatic flexible gripper grasping system;

[0048] Figure 2It is the front view of the pneumatic flexible gripper grasping system;

[0049] Figure 3 It is the side view of the pneumatic flexible gripper grasping system;

[0050] Figure 4 It is the top view of the pneumatic flexible gripper grasping system;

[0051] Figure 5 It is the axonometric view of the robotic arm;

[0052] Figure 6 It is the front view of the robotic arm;

[0053] Figure 7 It is the top view of the robotic arm;

[0054] Figure 8 It is the left view of the robotic arm;

[0055] Figure 9 It is the bottom view of the robotic arm;

[0056] Figure 10 It is the axonometric view of the robotic arm fixing device;

[0057] Figure 11 It is the axonometric view of the flexible gripper;

[0058] Figure 12 It is the front view of the flexible gripper;

[0059] Figure 13 It is the top view of the flexible gripper;

[0060] Figure 14 It is the bottom view of the flexible gripper;

[0061] Figure 15 It is the left view of the flexible gripper;

[0062] Figure 16 It is the right view of the flexible gripper;

[0063] Figure 17 It is the structural schematic diagram of the pneumatic flexible arm in the flexible gripper;

[0064] Figure 18 It is Figure 17 the front view of the pneumatic flexible arm shown;

[0065] Figure 19 It is the structural schematic diagram of the inner body;

[0066] Figure 20 It is Figure 19 the top view of the inner body shown;

[0067] Figure 21 It is Figure 17In the pneumatic flexible arm shown, a schematic structural diagram of the corrugated outer body;

[0068] Figure 22 is Figure 21 a top view of the structure shown;

[0069] Figure 23 is Figure 21 a front view of the structure shown;

[0070] Figure 24 is Figure 17 a cross-sectional view of the pneumatic flexible arm shown;

[0071] Figure 25 is Figure 17 an isometric view of the pneumatic flexible arm shown;

[0072] Figure 26 is Figure 17 a schematic diagram of the state of the pneumatic flexible arm after bending.

[0073] Explanation of symbols in the figure:

[0074] 100. Frame; 200. First lead screw slide module, 201. X-axis guide rod, 202. Y-axis guide rod, 203. Stepper motor X, 200-1. First slider, 200-2. Second slider; 210. Second lead screw slide module, 204. Stepper motor Y, 210-1. Slider one, 210-2. Slider two; 300. Robot arm, 301. Fixed fixture, 301-1. Upper part of the fixed fixture, 301-2. Middle part of the fixed fixture, 301-3. Lower part of the fixed fixture, 301-4. Y-axis guide rod linear bearing, 301-5. X-axis guide rod linear bearing, 302. Left servo motor, 303. Left transmission gear, 304. Left connecting rod, 305. Right servo motor, 306. Right transmission gear, 307. Right connecting rod, 308. Upper fixing plate, 309. Front fixing plate, 310. Rear fixing plate, 311. Lower fixing plate, 312. Lower fixing plate; 400. Flexible gripper, 401. Pneumatic flexible arm, 1. Inner body, 1-1. Left corrugated part, 1-2. Right corrugated part; 2. Corrugated outer body, 2-1. Arc-shaped corrugated part, 2-2. Semi-circular deformation air chamber, 2-3. Gas channel; 4. Luer connector; 402. Pneumatic flexible arm fixing plate, 403. Air duct, 404. Air duct adapter, 405. Air supply pipe. Detailed implementation method

[0075] As Figures 1 - 4As shown in the figure, the pneumatic flexible gripper grasping system includes a frame 100, a first lead screw sliding table module 200, a second lead screw sliding table module 210, an X-axis guide rod 201, a Y-axis guide rod 202, a robotic arm 300, and a flexible gripper 400. The first lead screw sliding table module 200 and the second lead screw sliding table module 210 are installed on the frame 100. The robotic arm 300 is installed at the intersection of the X-axis guide rod and the Y-axis guide rod. The flexible gripper 400 is installed at the bottom of the robotic arm 300.

[0076] As Figures 5 - 8 shown in the figure, the robotic arm 300 includes a fixed fixture 301, a left servo motor 302, a left transmission gear 303, a left connecting rod 304, a right servo motor 305, a right transmission gear 306, a right connecting rod 307, an upper fixing plate 308, a front fixing plate 309, a rear fixing plate 310, a lower fixing plate 311, and a lower fixing plate 312. The fixed fixture 301 is installed on the upper fixing plate 308. The left servo motor 302 and the right servo motor 305 are respectively fixedly installed on the front fixing plate 309. The left transmission gear 303 is provided with a rod portion and a tooth portion. The tooth portion of the left transmission gear 303 is connected to the output end of the left servo motor 302. The right transmission gear 306 is provided with a rod portion and a tooth portion. The tooth portion of the right transmission gear 306 is connected to the output end of the right servo motor 305. The tooth portions of the left transmission gear 303 and the right transmission gear 306 are meshed. The upper end of the left connecting rod 304 is rotatably connected to the rod portion of the left transmission gear 303. The upper end of the right connecting rod 307 is rotatably connected to the rod portion of the right transmission gear 306. The left connecting rod 304 and the right connecting rod 307 are symmetrically arranged. The rod portions of the left transmission gear 303 and the right transmission gear 306 are symmetrically arranged.

[0077] There are through holes at the four corners of the fixed fixture 301, and there are also through holes in the upper fixing plate 308. The four through holes of these two parts can be concentric and have the same radius. The fixed fixture 301 and the fixing plate 308 are fixed together by double-headed studs.

[0078] As Figures 9 - 10As shown in the figure, the fixed fixture 301 includes an upper part 301-1 of the fixed fixture, a middle part 301-2 of the fixed fixture, a lower part 301-3 of the fixed fixture, a linear bearing 301-4 of the Y-axis guide rod, and a linear bearing 301-5 of the X-axis guide rod. The middle part 301-2 of the fixed fixture is fixedly connected to the lower part 301-3 of the fixed fixture. The linear bearing 301-5 of the X-axis guide rod is connected between the middle part 301-2 and the lower part 301-3 of the fixed fixture. The upper part 301-1 of the fixed fixture is fixedly connected to the middle part 301-2 of the fixed fixture. The linear bearing 301-4 of the Y-axis guide rod is connected between the upper part 301-1 and the middle part 301-2 of the fixed fixture. Among them, the linear bearing 301-4 of the Y-axis guide rod cooperates with the Y-axis guide rod 202, and the Y-axis guide rod 202 passes through the linear bearing 301-4 of the Y-axis guide rod. The linear bearing 301-5 of the X-axis guide rod cooperates with the X-axis guide rod 201, and the X-axis guide rod 201 passes through the linear bearing 301-5 of the X-axis guide rod. As Figures 1 - 4 As shown in the figure, the first lead screw slide module 200 is provided with a lead screw, a stepping motor X203, a first slider 200-1, and a second slider 200-2. When the stepping motor X203 works, the first slider 200-1 and the second slider 200-2 move along the X-axis direction. One end of the X-axis guide rod 201 is fixedly connected to the first slider 200-1, and the other end of the X-axis guide rod 201 is fixedly connected to the second slider 200-2. The second lead screw slide module 210 is provided with a lead screw, a stepping motor Y204, a first slider 210-1, and a second slider 210-2. When the stepping motor Y204 works, the first slider 210-1 and the second slider 210-2 move along the Y-axis direction. One end of the Y-axis guide rod 202 is fixedly connected to the first slider 210-1, and the other end of the Y-axis guide rod 202 is fixedly connected to the second slider 210-2.

[0079] When the stepping motor X203 works, it can drive the X-axis guide rod 201 to move along the X-axis direction, and the X-axis guide rod 201 drives the fixed fixture 301 to move in the X-axis direction along the Y-axis guide rod 202; when the stepping motor Y204 works, it can drive the Y-axis guide rod 202 to move along the Y-axis direction, and the Y-axis guide rod 202 drives the fixed fixture 301 to move in the Y-axis direction along the X-axis guide rod 201; thereby driving the flexible gripper 400 to move in the X and Y axis directions, realizing the adjustment of the position of the flexible gripper 400. When the left servo motor 302 and the right servo motor 305 receive control signals, they can control the left transmission gear 303 and the right transmission gear 306 to rotate synchronously within a certain range, thereby driving the flexible gripper 400 to move in the Z-axis direction.

[0080] As Figures 11 - 19As shown, the flexible gripper 400 includes a pneumatic flexible arm 401, a pneumatic flexible arm fixing plate 402, an air duct 403, an air duct adapter 404, and an air supply pipe 405. Among them, three pneumatic flexible arms 401 are connected to the pneumatic flexible arm fixing plate 402. The lower ends of the three air ducts 403 are respectively connected to the three pneumatic flexible arms 401, and the upper ends of the three air ducts 403 are respectively connected to the three gas outlets of the air duct adapter 404. The air duct adapter 404 is provided with one gas inlet and three gas outlets, and the air supply pipe 405 is connected to the gas inlet of the air duct adapter 404. The air duct adapter 404 is fixedly connected to the lower fixing plate 311 and the lower fixing plate 312. The air duct adapter 404 is located in the horizontal plane.

[0081] It should be noted that the air supply pipe 405 is connected to a gas pumping device, and the gas inlet and outlet can be controlled through this device, so as to control the synchronous change of different postures of the pneumatic flexible arm 401, and further meet the actual grasping needs of different objects in different situations, and realize the grasping of objects with different shapes.

[0082] As Figure 17 and 18 shown, the pneumatic flexible arm 401 includes an inner body 1, a corrugated outer body 2, and a Luer connector 4. The inner body 1 is connected to the corrugated outer body 2, and the Luer connector 4 is connected to the rear end of the corrugated outer body 2. The front ends of the corrugated outer body 2 and the inner body 1 together form the free end of the pneumatic flexible arm. The material of the inner body 1 is a flexible material, and the material of the corrugated outer body 2 is a flexible material.

[0083] As Figure 19 and 20 shown, a number of left corrugated parts 1-1 are provided on the left side of the inner body 1, and a number of right corrugated parts 1-2 are provided on the right side of the inner body 1. One left corrugated part 1-1 and one right corrugated part 1-2 are arranged oppositely. As Figure 20 shown, the left end of the inner body 1 is the front end of the inner body 1, and the right end of the inner body 1 is its rear end. It can be seen from the figure that the width of the inner body 1 gradually decreases from the rear end to the front end.

[0084] As Figure 21 、 22As shown in FIGS. 23, a gas passage 2-3 is provided at the top of the corrugated outer body 2, and the gas passage 2-3 is distributed along the length direction of the corrugated outer body 2. The corrugated outer body 2 is provided with a plurality of arc-shaped corrugated portions 2-1, and the plurality of arc-shaped corrugated portions 2-1 are arranged in a line along the length direction of the corrugated outer body 2. The angle between the arc-shaped corrugated portion 2-1 and the axis of the corrugated outer body 2 is 90°. The corrugated outer body 2 is further provided with a plurality of semi-circular deformation air chambers 2-2. The number of the semi-circular deformation air chambers 2-2 is the same as the number of the arc-shaped corrugated portions 2-1. One semi-circular deformation air chamber 2-2 corresponds to one arc-shaped corrugated portion 2-1. The semi-circular deformation air chamber 2-2 extends downward from the top of the corrugated outer body 2 to the arc-shaped corrugated portion 2-1. The plurality of semi-circular deformation air chambers 2-2 are arranged in a line along the length direction of the corrugated outer body 2. The angle between the semi-circular deformation air chamber 2-2 and the axis of the corrugated outer body 2 is 90°. The gas passage 2-3 communicates with each semi-circular deformation air chamber 2-2. It can be seen from the figure that from the rear end to the front end, the width of the corrugated outer body 2 gradually becomes smaller, that is, the widths of the plurality of arc-shaped corrugated portions 2-1 gradually become smaller. Since the semi-circular deformation air chamber 2-2 matches the arc-shaped corrugated portion 2-1, the width of the semi-circular deformation air chamber 2-2 also gradually becomes smaller. In addition, from the rear end to the front end, the thickness of the corrugated outer body 2 gradually becomes smaller. Since the thickness of the corrugated outer body 2 gradually becomes smaller, the depths of the plurality of semi-circular deformation air chambers 2-2 gradually become smaller.

[0085] The Luer connector 4 is connected to the rear end of the corrugated outer body 2, and the Luer connector 4 communicates with the gas passage 2-3.

[0086] Reference Figure 17 、 18 Referring to FIGS. 24 and 25, the inner body 1 is connected to the top of the corrugated outer body 2. The left corrugated portion 1-1 of the inner body 1 corresponds to the left side of the arc-shaped corrugated portion 2-1 of the corrugated outer body 2, and the right corrugated portion 1-2 corresponds to the right side of the arc-shaped corrugated portion 2-1 of the corrugated outer body 2. That is to say, a group formed by the left corrugated portion 1-1 and the right corrugated portion 1-2 corresponds to one arc-shaped corrugated portion 2-1.

[0087] It should be noted that the Luer connector 4 is a preferred method, and other known or air-permeable connectors can also be used.

[0088] When inflating the gas passage 2-3 through the Luer connector 4, the gas in the gas passage 2-3 enters each semi-circular deformation air chamber 2-2, so that the semi-circular deformation air chamber 2-2 expands and deforms. The expansion and deformation of each semi-circular deformation air chamber 2-2 can cause the entire corrugated outer body 2 to generate a bending deformation toward the inner body 1 direction. Finally, the inner body 1 is bent and deformed, as shown in Figure 26As shown, a bend is formed that can wrap the object to be grasped, contact and wrap the object to be grasped, thereby achieving the grasping of the object. The degree of bending deformation increases with the increase in the volume of the gas filled. In the state where the pneumatic flexible arm is bent and deformed, the pneumatic flexible arm can be restored to its initial state by deflating through the Luer connector 4.

[0089] The lower end of the air duct 403 is connected to the Luer connector 4.

[0090] It can be seen that the use of the pneumatic flexible arm 401 can well enhance the flexibility, safety and stability of the system.

[0091] The following describes the manufacturing method of the above pneumatic flexible arm:

[0092] First, place the Luer connector 4 in the first mold for manufacturing the corrugated outer body 2, pour the silicone raw liquid into the first mold, and then after a series of refined treatments such as bubble extraction and feeding, wait for it to naturally form to manufacture the integrally formed corrugated outer body 2, and the Luer connector 4 is embedded at the end of the corrugated outer body 2. Secondly, pour the silicone raw liquid into the second mold for manufacturing the inner body 1, and also go through refined treatment. Then, invert the formed corrugated outer body 2 that has not been removed from the mold onto the second mold filled with unformed silicone, requiring the unformed silicone in the second mold to be closely attached to the formed silicone in the first mold, and the left corrugated part 1-1, right corrugated part 1-2 of the inner body 1 to correspond and match with the arc-shaped corrugated part 2-1. Finally, wait for it to naturally form and then perform demolding treatment to complete the preparation of the entire flexible arm, and at the same time ensure that its airtight performance meets the requirements.

[0093] The pneumatic flexible arm 401 has a fast response speed, high motion stability and load capacity.

[0094] The following introduces the working process of the above pneumatic flexible gripper grasping system:

[0095] When the vision module recognizes the object to be grasped, the vision module transmits a signal to the STM32 single-chip microcomputer, and then the STM32 single-chip microcomputer transmits control signals to the stepping motor X203 and stepping motor Y204. When the stepping motor X203 and stepping motor Y204 receive the control signals, they will drive the fixed fixture 301 to move along the X-axis guide rod 201 and Y-axis guide rod 202 directions, so that the flexible gripper 400 is positioned at the corresponding XY coordinates.

[0096] After the flexible gripper 400 completes the XY coordinate positioning of the grasped object, the stepper motor X203 and the stepper motor Y204 stop operating, and the STM32 single-chip microcomputer transmits control signals to the left servo 302 and the right servo 305. After the left servo 302 and the right servo 305 receive the control signals, they will drive the left transmission gear 303 and the right transmission gear 306 to rotate synchronously within a certain range, causing the flexible gripper 400 to move along the Z direction, and further positioning the flexible gripper 400 to the specific coordinates of the object to be grasped.

[0097] After the flexible gripper 400 completes the positioning of the specific coordinates of the object to be grasped, the STM32 single-chip microcomputer will send a control signal to the air pumping device, causing the air pumping device to synchronously supply air to the three pneumatic flexible arms 401 through the air supply pipe 405, the air pipe adapter 404, and the three air guide pipes 403. The STM32 single-chip microcomputer calculates the air pressure that needs to be supplied according to the size and shape of the grasped object, controls the air supply volume of the air pumping device, and further controls the postures of the three pneumatic flexible arms 401 to achieve the grasping of the object.

[0098] Through the control of the STM32 single-chip microcomputer, the positioning of the stepper motor X203, the stepper motor Y204, the left servo 302, and the right servo 305, and the air supply of the air pumping device, the precise grasping of the target object by the system can be ensured. At the same time, based on the characteristics of the pneumatic flexible arm 401, it can be seen that it has a significant effect on reducing the damage to soft and fragile items such as fruits, and can significantly improve the grasping efficiency and integrity of soft and fragile items. For the sorting work of soft and fragile fruits such as strawberries, apples, and peaches, the system has significant advantages.

[0099] It should be noted that in the specification drawings, the included angles between any two of the three pneumatic flexible arms 401 are all 120°. However, for different grasping requirements, the number of pneumatic flexible arm units that can be connected in parallel is not limited to three, and the angle between every two adjacent units is not limited to 120°. The number of air guide pipes 403 and the number of interfaces of the air pipe adapter 404 can be appropriately changed according to different needs.

[0100] In order to more precisely control the deformation of the three pneumatic flexible arms 401 for the target object, when the three pneumatic flexible arms 401 are evenly distributed along the circumference, the air pipe adapter 404 and the air supply pipe 405 are not provided, and the three air guide pipes 403 are directly connected to the air pumping device respectively to achieve independent and coordinated deformation, so as to complete the flexible wrapping and clamping of the target object. The three pneumatic flexible arms 401 are respectively denoted as pneumatic flexible arm A1, A2, and A3. The specific control method includes the following steps:

[0101] Step 1: Modeling the size of the target object and extracting the shape curvature. Image data of the object to be grasped is collected through the vision recognition module carried by the system, and the three-dimensional boundary size of the target object is extracted. Let its length, width, and height be L, W, and H respectively. Thus, the equivalent volume of the object can be calculated:

[0102] V = L·W·H (9)

[0103] Furthermore, an equivalent enveloping sphere model is constructed to estimate the average surface curvature. The equivalent curvature radius is defined as:

[0104]

[0105] Based on the estimation of the principal curvature, the complexity of the object's contour is used to construct the average principal curvature

[0106]

[0107] Step 2: Inverse deduction of the target curvature and calculation of the target pressure. Each pneumatic flexible arm 401 will generate a bending deformation after being pressurized, and its end posture is characterized by its bending angle θ i The target object's enveloping curvature κ * is set as: where ∈ is the grasping safety redundancy term to enhance the clamping and enveloping ability. Given that the length of each pneumatic flexible arm 401 is L0, the corresponding posture bending angle is θ i = κ * ·L0. Let the posture angles of the three pneumatic flexible arms form a posture vector Combined with the size and shape of the target object, a target posture vector is generated: To achieve this target posture, the corresponding internal pressure needs to be applied to the air chamber of the pneumatic flexible arm. There is the following non-linear mapping relationship between the air pressure and the posture angle: θ i (t) = a1P i 3 (t) + a2P i 2 (t) + a3P i (t) + a4. According to the target posture, the required target air pressure P id = f -1 (θ i ) is calculated, and the target pressure vector of the three pneumatic flexible arms is obtained: P d (t) = [P 1d (t), P 2d (t), P 3d (t)] T , and this result will be used as the target reference input of the pneumatic controller to enter the next closed-loop regulation stage.

[0108] Step 3: Pose-oriented closed-loop air pressure control strategy. To achieve the target pressure, the STM32 single-chip microcomputer independently sets a closed-loop air pressure control loop for each pneumatic flexible arm. Define the system state variables as: P(t) = [P1(t), P2(t), P3(t)] T , and the control input is the gas volume flow rate vector: φ(t) = [φ1(t), φ2(t), φ3(t)] T , and the system dynamics is: where f(·) represents the pneumatic nonlinear change term, and B is the gas path flow-pressure coefficient matrix. Construct the following PID controller for closed-loop air pressure regulation, and the control law is:

[0109]

[0110] where the error term is defined as: e i (t) = P id (t) - P i (t). The actual air supply is delivered to the three pneumatic flexible arms through three air ducts 403 by the air pumping device, and the adjustment process is updated every 5 ms.

[0111] Finally, by performing high-precision closed-loop control on the internal air pressure of each pneumatic flexible arm, the system ensures that the output pose angle θ of the pneumatic flexible arm i accurately approaches the expected value, realizes the spatial wrapping pose control, and completes the grasping task.

[0112] The above description is only for the preferred embodiments of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the scope defined by the claims of the present invention shall fall within the protection scope of the present invention.

Claims

1. A pneumatic flexible gripper grasping system, characterized in that, It includes a frame, a first lead screw slide module, a second lead screw slide module, an X-axis guide rod, a Y-axis guide rod, a robotic arm, and a flexible gripper. The first lead screw slide module and the second lead screw slide module are respectively connected to the frame; The robotic arm includes a fixed fixture, a left servo motor, a left transmission gear, a left connecting rod, a right servo motor, a right transmission gear, a right connecting rod, an upper fixing plate, a front fixing plate, a rear fixing plate, a lower fixing plate, and a lower fixing plate. The fixed fixture is fixedly connected to the upper fixing plate. The left servo motor and the right servo motor are respectively connected to the front fixing plate. The left transmission gear is provided with a rod portion and a tooth portion. The tooth portion of the left transmission gear is connected to the output end of the left servo motor. The right transmission gear is provided with a rod portion and a tooth portion. The tooth portion of the right transmission gear is connected to the output end of the right servo motor. The tooth portions of the left transmission gear and the right transmission gear are meshed; the upper end of the left connecting rod is rotatably connected to the rod portion of the left transmission gear, and the upper end of the right connecting rod is rotatably connected to the rod portion of the right transmission gear; the left connecting rod and the right connecting rod are symmetrically arranged, and the rod portions of the left transmission gear and the right transmission gear are symmetrically arranged; The fixed fixture includes an upper part of the fixed fixture, a middle part of the fixed fixture, a lower part of the fixed fixture, a Y-axis guide rod linear bearing, and an X-axis guide rod linear bearing. The middle part of the fixed fixture is fixedly connected to the lower part of the fixed fixture. The X-axis guide rod linear bearing is connected between the middle part of the fixed fixture and the lower part of the fixed fixture. The upper part of the fixed fixture is fixedly connected to the middle part of the fixed fixture. The Y-axis guide rod linear bearing is connected between the upper part of the fixed fixture and the middle part of the fixed fixture; the Y-axis guide rod passes through the Y-axis guide rod linear bearing, and the X-axis guide rod passes through the X-axis guide rod linear bearing; the first lead screw slide module is provided with a first slider and a second slider. One end of the X-axis guide rod is fixedly connected to the first slider, and the other end of the X-axis guide rod is fixedly connected to the second slider; the second lead screw slide module is provided with a first slider and a second slider. One end of the Y-axis guide rod is fixedly connected to the first slider, and the other end of the Y-axis guide rod is fixedly connected to the second slider; The flexible gripper includes a pneumatic flexible arm fixing plate, a tracheal adapter, an air supply pipe, three pneumatic flexible arms, and three air guide pipes. The three pneumatic flexible arms are connected to the pneumatic flexible arm fixing plate. The lower ends of the three air guide pipes are respectively communicated with the three pneumatic flexible arms. The tracheal adapter is provided with one gas inlet and three gas outlets. The upper ends of the three air guide pipes are respectively connected to the three gas outlets of the tracheal adapter. The air supply pipe is connected to the gas inlet of the tracheal adapter; the tracheal adapter is fixedly connected to the lower fixing plate and the lower fixing plate, and the tracheal adapter is located in the horizontal plane.

2. The pneumatic flexible gripper grasping system according to claim 1, characterized in that The pneumatic flexible arm includes an inner body, a corrugated outer body, and a Luer connector; several left corrugated portions are provided on the left side of the inner body, and several right corrugated portions are provided on the right side of the inner body. The left corrugated portions and the right corrugated portions are arranged oppositely. The width of the inner body gradually decreases from its rear end to its front end; The top of the corrugated outer body is provided with a gas channel, which is distributed along the length direction of the corrugated outer body. The corrugated outer body is provided with a number of arc-shaped corrugated parts, and the number of arc-shaped corrugated parts are arranged in a line along the length direction of the corrugated outer body. The angle between the arc-shaped corrugated part and the axis of the corrugated outer body is 90°. The corrugated outer body is provided with a number of semi-circular deformation air chambers, and the number of semi-circular deformation air chambers are arranged in a line along the length direction of the corrugated outer body. The angle between the semi-circular deformation air chamber and the axis of the corrugated outer body is 90°. The number of semi-circular deformation air chambers is the same as the number of arc-shaped corrugated parts, and one semi-circular deformation air chamber corresponds to one arc-shaped corrugated part. The semi-circular deformation air chamber extends downward from the top of the corrugated outer body to the arc-shaped corrugated part, and a number of semi-circular deformation air chambers are all communicated with the gas channel; from the rear end to the front end of the corrugated outer body, the widths of a number of arc-shaped corrugated parts gradually become smaller, the thickness of the corrugated outer body gradually becomes smaller, the widths of a number of semi-circular deformation air chambers gradually become smaller, and the depths of a number of semi-circular deformation air chambers gradually become smaller; The Luer connector is connected to the rear end of the corrugated outer body, and the Luer connector is communicated with the gas channel; The inner body is connected to the top of the corrugated outer body. The left corrugated part of the inner body corresponds to the left side of the arc-shaped corrugated part of the corrugated outer body, and the right corrugated part corresponds to the right side of the arc-shaped corrugated part of the corrugated outer body; The material of the inner body is a flexible material, and the material of the corrugated outer body is a flexible material; The Luer connector of the pneumatic flexible arm is connected to the lower end of the air duct.

3. The pneumatic flexible gripper grasping system according to claim 2, characterized in that, From the rear end to the front end of the corrugated outer body, the width of the gas channel gradually becomes larger.

4. The pneumatic flexible gripper grasping system according to claim 3, characterized in that, The inner body and the top of the corrugated outer body are connected by an integral molding method.

5. The pneumatic flexible gripper grasping system according to claim 1 or 2, characterized in that, The three pneumatic flexible arms are evenly distributed along the circumferential direction.

6. A pneumatic flexible gripper grasping system, characterized in that, It includes a frame, a first lead screw sliding table module, a second lead screw sliding table module, an X-axis guide rod, a Y-axis guide rod, a robotic arm and a flexible gripper. The first lead screw sliding table module and the second lead screw sliding table module are respectively connected to the frame; The robotic arm includes a fixed fixture, a left servo motor, a left transmission gear, a left connecting rod, a right servo motor, a right transmission gear, a right connecting rod, an upper fixing plate, a front fixing plate, a rear fixing plate, a lower fixing plate and a lower fixing plate. The fixed fixture is fixedly connected to the upper fixing plate. The left servo motor and the right servo motor are respectively connected to the front fixing plate. The left transmission gear is provided with a rod part and a tooth part, and the tooth part of the left transmission gear is connected to the output end of the left servo motor. The right transmission gear is provided with a rod part and a tooth part, and the tooth part of the right transmission gear is connected to the output end of the right servo motor. The tooth parts of the left transmission gear and the right transmission gear are meshed; the upper end of the left connecting rod is rotatably connected to the rod part of the left transmission gear, and the upper end of the right connecting rod is rotatably connected to the rod part of the right transmission gear; the left connecting rod and the right connecting rod are symmetrically arranged, and the rod parts of the left transmission gear and the right transmission gear are symmetrically arranged; The fixed fixture includes an upper part of the fixed fixture, a middle part of the fixed fixture, a lower part of the fixed fixture, a linear bearing for the Y-axis guide rod, and a linear bearing for the X-axis guide rod. The middle part of the fixed fixture is fixedly connected to the lower part of the fixed fixture. The X-axis guide rod linear bearing is connected between the middle part of the fixed fixture and the lower part of the fixed fixture. The upper part of the fixed fixture is fixedly connected to the middle part of the fixed fixture. The Y-axis guide rod linear bearing is connected between the upper part of the fixed fixture and the middle part of the fixed fixture. The Y-axis guide rod passes through the Y-axis guide rod linear bearing, and the X-axis guide rod passes through the X-axis guide rod linear bearing. The first lead screw slide module is provided with a first slider and a second slider. One end of the X-axis guide rod is fixedly connected to the first slider, and the other end of the X-axis guide rod is fixedly connected to the second slider. The second lead screw slide module is provided with a first slider and a second slider. One end of the Y-axis guide rod is fixedly connected to the first slider, and the other end of the Y-axis guide rod is fixedly connected to the second slider. The flexible gripper includes a pneumatic flexible arm fixing plate, three pneumatic flexible arms, and three air ducts. The three pneumatic flexible arms are connected to the pneumatic flexible arm fixing plate. The lower ends of the three air ducts are respectively communicated with the three pneumatic flexible arms. The pneumatic flexible arm fixing plate is fixedly connected to the lower fixing plate. The air duct adapter is located in the horizontal plane. The pneumatic flexible arm includes an inner body, a corrugated outer body, and a Luer connector. A plurality of left corrugated parts are provided on the left side of the inner body. A plurality of right corrugated parts are provided on the right side of the inner body. The left corrugated parts and the right corrugated parts are arranged oppositely. The width of the inner body gradually decreases from its rear end to its front end. The top of the corrugated outer body is provided with a gas channel, which is distributed along the length direction of the corrugated outer body. The corrugated outer body is provided with a plurality of arc-shaped corrugated parts, which are arranged in a row along the length direction of the corrugated outer body. The angle between the arc-shaped corrugated part and the axis of the corrugated outer body is 90°. The corrugated outer body is provided with a plurality of semi-circular deformation air chambers, which are arranged in a row along the length direction of the corrugated outer body. The angle between the semi-circular deformation air chamber and the axis of the corrugated outer body is 90°. The number of semi-circular deformation air chambers is the same as the number of arc-shaped corrugated parts. One semi-circular deformation air chamber corresponds to one arc-shaped corrugated part. The semi-circular deformation air chamber extends downward from the top of the corrugated outer body to the arc-shaped corrugated part. A plurality of semi-circular deformation air chambers are all communicated with the gas channel. From the rear end to the front end of the corrugated outer body, the widths of the plurality of arc-shaped corrugated parts gradually decrease, the thickness of the corrugated outer body gradually decreases, the widths of the plurality of semi-circular deformation air chambers gradually decrease, and the depths of the plurality of semi-circular deformation air chambers gradually decrease. The Luer connector is connected to the rear end of the corrugated outer body and is communicated with the gas channel. The inner body is connected to the top of the corrugated outer body. The left corrugated part of the inner body corresponds to the left side of the arc-shaped corrugated part of the corrugated outer body, and the right corrugated part corresponds to the right side of the arc-shaped corrugated part of the corrugated outer body. The material of the inner body is a flexible material, and the material of the corrugated outer body is a flexible material. The Luer connector of the pneumatic flexible arm is connected to the lower end of the air duct; The method for controlling the three pneumatic flexible arms to grasp the target object includes the following steps: First step, respectively denote the three pneumatic flexible arms as pneumatic flexible arm A1, A2, and A3; perform target object size modeling and shape curvature extraction; Collect the image data of the target object through the vision module, extract the three-dimensional boundary size of the target object, and assume its length, width, and height are L, W, and H respectively. From this, the equivalent volume of the object can be calculated: V = L·W·H (1) Further construct an equivalent enveloping sphere model to estimate the average surface curvature, and define the equivalent curvature radius as: Construct the average principal curvature Second step, target curvature back-calculation and target pressure calculation; The pneumatic flexible arm bends and deforms after being pressurized, and its end attitude is characterized by its bending angle θ i characterizes; the wrapping curvature κ of the target object * Set as: where ∈ is the grasping safety redundancy term; define the length of each pneumatic flexible arm as L0, then the corresponding attitude bending angle is θ i = κ * ·L0; let the attitude angles of the three pneumatic flexible arms form an attitude vector Combined with the size and shape of the target object, generate a target attitude vector: To achieve this target attitude; there is the following non-linear mapping relationship between the air pressure applied to the pneumatic flexible arm and the attitude angle: θ i (t) = a1P i 3 (t) + a2P i 2 (t) + a3P i (t) + a4, according to the target attitude, inversely deduce the required target air pressure P id = f -1 (θ i ), calculate the target pressure vector of the three pneumatic flexible arms: P d (t) = [P 1d (t), P 2d (t), P 3d (t)] T , this result will be used as the target reference input for pneumatic control and enter the next closed-loop regulation stage; Third step, attitude-guided closed-loop air pressure control strategy; Define the system state variable as: P(t) = [P1(t), P2(t), P3(t)] T , and the control input is the gas volume flow rate vector: φ(t) = [φ1(t), φ2(t), φ3(t)] T , and the system dynamics is: where f(·) represents the pneumatic nonlinear variation term, B is the gas path flow rate-pressure coefficient matrix, construct the following PID controller for closed-loop air pressure regulation, and the control law is: where the error term is defined as: e i (t) = P id (t) - P i (t).

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