Automatic motion control method, device and medium for rope-driven flexible robot joints

Abstract

The present invention discloses a method, device, and medium for automatic motion control of a rope-pulled flexible robot joint, belonging to the field of flexible robot control. The method comprises: Step 1: setting a coordinate system for a variable-rigidity rope-pulled flexible robot joint, and determining the rope length and joint angle variable representation according to the coordinate system; Step 2: completing the forward kinematics solution of the variable-rigidity rope-pulled flexible robot joint based on the geometric relationship and the constant curvature model; Step 3: completing the inverse kinematics solution through mathematical derivation based on the result; Step 4: automatically controlling the motion of the variable-rigidity rope-pulled flexible robot joint based on the mapping relationship between the traction rope length and the end-end posture matrix determined by the inverse kinematics solution result. The present invention performs kinematic modeling based on the constant curvature model, obtains the mapping relationship between the traction rope length and the end-end posture matrix of the robot joint, drives the robot joint to the desired posture according to the mapping relationship, and realizes motion control of the variable-rigidity rope-pulled flexible robot joint.

Description

Technical Field

[0001] The invention relates to the field of flexible robot control, and in particular to an automatic motion control method for a flexible robot joint pulled by a variable stiffness rope. Background Art

[0002] A rope-pulled flexible robot is a robot whose end effector is pulled by multiple ropes. It can adapt to different working environments and task requirements. Its flexible joints allow for greater maneuverability during operation, reducing the need for precise data. It can better adapt to various unstructured environments and is less susceptible to damage from external impacts. It can complete complex tasks, especially in confined and unstructured environments.

[0003] Due to the high deformability of flexible robots, solving their forward and inverse kinematics presents challenges. While complex kinematic models improve solution accuracy, their limited computational speed restricts practical applications. Conversely, overly simplistic kinematic models suffer from significant solution errors and are unsuitable for practical applications. Therefore, achieving efficient and accurate solutions for the forward and inverse kinematics of flexible robot joints and enabling automated motion control is a pressing issue.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide an automatic motion control method, equipment and medium for the joints of a rope-pulled flexible robot, which can achieve efficient and accurate forward and inverse kinematics solutions of the flexible robot joints, perform automatic motion control, and realize the execution of operation tasks in complex environments, thereby solving the above-mentioned technical problems existing in the prior art.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A method for automatically controlling the joint motion of a rope-pulled flexible robot is provided, which is used to automatically control the joint motion of a rope-pulled flexible robot composed of an end motion platform, a flexible control support, a joint traction mechanism, a variable stiffness traction servo, and a fixed base, and comprises:

[0008] Step 1: Set the coordinate system of the variable stiffness rope-traction flexible robot joint fixed base and the end motion platform, and determine the rope length and joint angle variable representation according to the set coordinate system;

[0009] Step 2: Based on the determined rope length and joint angle variables, the forward kinematics solution of the variable stiffness rope-traction flexible robot joint is completed according to the geometric relationship and constant curvature model:

[0010] Step 3: Based on the forward kinematics solution, the inverse kinematics solution of the variable stiffness rope traction flexible robot joint is completed through mathematical derivation:

[0011] Step 4: Automatically control the motion of the variable stiffness rope traction flexible robot joints based on the mapping relationship between the traction rope length and the terminal pose matrix determined by the inverse kinematics solution.

[0012] A processing device comprising:

[0013] at least one memory for storing one or more programs;

[0014] At least one processor is capable of executing one or more programs stored in the memory. When the one or more programs are executed by the processor, the processor is enabled to implement the method described in the present invention.

[0015] A readable storage medium stores a computer program, which can implement the method described in the present invention when the computer program is executed by a processor.

[0016] Compared with the prior art, the method, device and medium for automatically controlling the motion of a rope-pulled flexible robot joint provided by the present invention have the following beneficial effects:

[0017] The kinematic modeling of the rope-traction flexible robot joint is carried out based on the constant curvature model. According to the structural characteristics of the joint, a kinematic model that takes into account both accuracy and efficiency is established. The mapping relationship between the traction rope length and the end pose matrix of the robot joint is obtained. The traction rope drive mechanism changes the traction rope length to drive the robot joint to reach the desired pose, realizing automatic motion control of the variable stiffness rope-traction flexible robot joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is a flow chart of the automatic motion control method for the variable stiffness rope-traction flexible robot joint provided by an embodiment of the present invention.

[0020] Figure 2 Schematic diagram of the kinematic model of the variable stiffness rope traction flexible robot joint provided in an embodiment of the present invention.

[0021] Figure 3 A schematic diagram of the three-dimensional structure of a rope-traction flexible robot joint with variable stiffness provided by an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the main structure of a rope-traction flexible robot joint with variable stiffness provided by an embodiment of the present invention.

[0023] Figure 5 A schematic diagram of the exploded three-dimensional structure of a rope-traction flexible robot joint with variable stiffness provided by an embodiment of the present invention.

[0024] Figure 6 Schematic diagram of the three-dimensional structure of the flexible control support body of the variable stiffness rope-traction flexible robot joint provided by an embodiment of the present invention.

[0025] Figure 7 Schematic diagram of the structure of a three-dimensional flexible support sleeve assembly of a flexible control support body of a rope-traction flexible robot joint with variable stiffness provided by an embodiment of the present invention.

[0026] Figure 8 Schematic diagram of the three-dimensional structure of the movable support ring shaft assembly of the flexible control support body of the variable stiffness rope-traction flexible robot joint provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the specific content of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments, and do not constitute a limitation of the present invention. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0028] First, the following terms may be used in this article:

[0029] The term “and / or” means that either or both of them can be realized at the same time. For example, X and / or Y includes both “X” or “Y” and “X and Y”.

[0030] The terms "include," "comprises," "contains," "has," or other similar expressions should be interpreted as non-exclusive. For example, "including certain technical features (such as raw materials, components, ingredients, carriers, dosage forms, materials, dimensions, parts, components, mechanisms, devices, steps, procedures, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products, or manufactured articles)" should be interpreted as including not only the technical features explicitly listed, but also other technical features known in the art that are not explicitly listed.

[0031] The term "consisting of" excludes any technical features not explicitly listed. If used in a claim, this term renders the claim closed, excluding any technical features other than those explicitly listed, except for conventional impurities associated with them. If this term appears only in a clause of a claim, it limits only the elements explicitly listed in that clause; elements listed in other clauses are not excluded from the claim as a whole.

[0032] Unless otherwise specified or limited, the terms "mounted," "connected," "connect," and "fixed" should be interpreted broadly. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this document based on specific circumstances.

[0033] When concentration, temperature, pressure, size or other parameters are expressed in the form of a numerical range, the numerical range should be understood to specifically disclose all ranges formed by the pairing of any upper limit, lower limit, or preferred value within the numerical range, regardless of whether the range is explicitly stated. For example, if a numerical range of "2 to 8" is stated, the numerical range should be interpreted as including ranges of "2 to 7," "2 to 6," "5 to 7," "3 to 4 and 6 to 7," "3 to 5 and 7," "2 and 5 to 7," etc. Unless otherwise specified, the numerical ranges stated herein include both their endpoints and all integers and fractions within the numerical range.

[0034] The terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings and are only for the convenience and simplification of description, and do not explicitly or implicitly indicate that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation to this document.

[0035] The scheme provided by the present invention is described in detail below. The contents not described in detail in the examples of the present invention belong to the prior art known to professionals in this field. If specific conditions are not specified in the examples of the present invention, they are carried out according to conventional conditions in the field or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used in the examples of the present invention is not specified, they are all conventional products that can be purchased commercially.

[0036] like Figure 1As shown, an embodiment of the present invention provides an automatic motion control method for a rope-driven flexible robot joint, which is used to automatically control the motion of a variable stiffness rope-driven flexible robot joint composed of an end motion platform 1, a flexible control support body, a joint traction mechanism, a variable stiffness traction servo 10, and a fixed base 3, including the following steps:

[0037] Step 1: Set the coordinate system of the variable stiffness rope-traction flexible robot joint fixed base and the end motion platform, and determine the rope length and joint angle variable representation according to the set coordinate system;

[0038] Step 2: Based on the determined rope length and joint angle variables, the forward kinematics solution of the variable stiffness rope-traction flexible robot joint is completed according to the geometric relationship and constant curvature model:

[0039] Step 3: Based on the forward kinematics solution, the inverse kinematics solution of the variable stiffness rope traction flexible robot joint is completed through mathematical derivation:

[0040] Step 4: Automatically control the motion of the variable stiffness rope traction flexible robot joints based on the mapping relationship between the traction rope length and the terminal pose matrix determined by the inverse kinematics solution.

[0041] Preferably, in step 1 of the above method, the coordinate systems of the joint fixed base and the terminal motion platform of the variable stiffness rope traction flexible robot are set in the following manner, including:

[0042] The flexible control support body of the flexible robot joint pulled by the variable stiffness rope is used as a curve express;

[0043] The intersection points of the three traction ropes of the variable stiffness rope traction flexible robot joint and the bottom disk plane of the flexible control support are 、 and , and the intersection points with the plane of the end disk are 、 and , the center of the bottom disk plane is , the center of the end disk plane is ;

[0044] Base coordinate system Set at the bottom center of the flexible control support body, The axis is perpendicular to the bottom disk plane, The axis points from the center of the circle to the intersection of the first traction rope and the bottom disc plane ;

[0045] For the end tool coordinate system , The axis is perpendicular to the plane of the end disk, The axis points from the center of the end disk to the intersection of the first traction rope and the end disk plane ;

[0046] When the length of the three traction ropes changes, the support body is flexibly adjusted It will show the motion characteristics of bending to one side, and the normal vector of the end disk plane is Axis, and flexible control support At the end The tangent vectors at coincide with each other, that is, and axis, The axes together form a bending plane ,in is the intersection of the bending plane and the bottom disk plane, is the intersection of the bending plane and the end motion disk, and The intersection is ;

[0047] The rotation angle of the bending plane is expressed as It is called the bending azimuth ; The plane bending angle of the bending plane is expressed as , called the bending angle ;

[0048] Based on the constant curvature beam assumption, Is a constant value , the joint motion of the flexible robot with variable stiffness pulled by three ropes is determined by the bending azimuth angle and bending angle These two angles describe the two degrees of freedom of bending motion.

[0049] Preferably, in step 1 of the above method, the variable representation of the rope length and the joint angle is determined according to the set coordinate system in the following manner, including:

[0050] The lengths of the three traction ropes of the flexible robot joint with variable stiffness rope traction use The length of The values ​​are 1, 2, and 3. The length of the traction rope is expressed as:

[0051] (1);

[0052] in,

[0053] (2);

[0054] in, Indicates winding Coordinate axis rotation bending angle The rotation matrix of Indicates winding Coordinate axis rotation bending azimuth The rotation matrix of Indicates the radius of the disk, that is, the distance between the traction rope lead-out hole and the center of the disk, that is The distance, that is The superscript T represents the transpose of the matrix; express Around Rotate counterclockwise to Angle, and bending azimuth The relationship is expressed as:

[0055] (3);

[0056] Get the bending azimuth and bending angle With three traction rope lengths The mapping relationship between them is:

[0057] (4).

[0058] Preferably, in step 2 of the above method, the forward kinematics solution of the variable stiffness rope-traction flexible robot joint is completed according to the determined rope length and joint angle variable representation, based on the geometric relationship and the constant curvature model, including:

[0059] Base coordinate system To the end tool coordinate system The homogeneous transformation matrix The general form is:

[0060] (5);

[0061] in, Indicates the coordinate system from the base To the end tool coordinate system The three-dimensional rotation transformation matrix of Represents the base coordinate system to the end tool coordinate system The displacement vector Represented as a vector :

[0062] (6);

[0063] The three-dimensional rotation transformation matrix With the help of ZYZ Euler angle method, the bending azimuth and bending angle The derivation is:

[0064] (7);

[0065] In the above formulas (6) and (7), s represents sin, and c represents cos;

[0066] Combining formula (7) can get the length of the three traction ropes and bending azimuth and bending angle As well as the mapping relationship between the position and pose matrix, the forward kinematics solution of the variable stiffness rope-traction flexible robot joint is completed.

[0067] Preferably, in step 3 of the above method, the inverse kinematics solution of the variable stiffness rope traction flexible robot joint is completed by mathematical derivation based on the forward kinematics solution result in the following manner, including:

[0068] Three traction rope lengths and bending azimuth and bending angle The mapping relationship between them is:

[0069] (8);

[0070] Combining Equation (8) with Equation (7) yields the pose matrix and bending azimuth and bending angle and the length of the three traction ropes The mapping relationship is used to complete the inverse kinematics solution of the variable stiffness rope-traction flexible robot joints.

[0071] Preferably, in step 4 of the above method, the variable stiffness rope traction flexible robot joint is automatically controlled in the following manner according to the mapping relationship between the traction rope length and the terminal posture matrix determined by the inverse kinematics solution result, including:

[0072] According to the mapping relationship between the position and posture of the joint of the variable stiffness rope traction flexible robot and the length of the traction rope, the traction rope length is changed by pulling the traction rope driving mechanism, and the bending posture of the joint of the variable stiffness rope traction flexible robot is changed to achieve the desired posture, thereby realizing automatic motion control of the joint of the variable stiffness rope traction flexible robot.

[0073] Preferably, in the above method, in the controlled variable stiffness rope-traction flexible robot joint, the lower end of the flexible control support is connected to the fixed base 3, and the upper end is connected to the end motion platform 1;

[0074] The flexible control support body includes a flexible support sleeve assembly 6 and a movable support ring shaft assembly 9. The flexible support sleeve assembly 6 is nested outside the movable support ring shaft assembly 9 and connected to form a flexible control support body structure;

[0075] The variable stiffness traction servo 10 is installed at the center of the fixed base 3, connecting and pulling the flexible support sleeve assembly 6 and the movable support ring shaft assembly 9 to rotate relative to each other to change the stiffness of the flexible control support body;

[0076] The joint traction mechanism is installed on the fixed base 3, and the terminal motion platform 1 is pulled by the traction rope to drive the flexible control support body to bend, thereby realizing the bending movement of the flexible robot joint pulled by the variable stiffness rope.

[0077] Preferably, in the above method, the flexible support sleeve assembly 6 and the movable support ring shaft assembly 9 are both made of flexible materials;

[0078] The lower end of the flexible support sleeve assembly 6 is connected to the fixed base 3, and the upper end is connected to the terminal motion platform 1.

[0079] The flexible support sleeve assembly 6 is a sleeve structure, and at least one sleeve support ring is provided in the inner hole of the sleeve; the sleeve support ring includes more than three fan-shaped sleeve support columns 61 uniformly distributed in the circumferential direction;

[0080] The movable support ring shaft assembly 9 includes a movable flange 91 and a core column 92. The lower end of the core column 92 is fixed to the center of the movable flange 91. The core column 92 is provided with at least one layer of core column support ring on the movable flange 91. The core column support ring includes more than three fan-shaped core column support columns 93 uniformly distributed in the circumferential direction.

[0081] The upper end of the core column 92 extends into the central hole formed by the inner arc surface of the sleeve support column 61;

[0082] The sleeve support column 61 and the core column support column 93 are spaced apart and their end faces contact each other to support the flexible support sleeve assembly 6;

[0083] The variable stiffness traction steering gear 10 is connected to and pulls the movable support ring shaft assembly 9 to rotate relative to the flexible support sleeve assembly 6, adjusts the contact area between the end faces of the sleeve support column 61 and the core column support column 93, and changes the stiffness of the flexible control support body.

[0084] Preferably, the joint traction mechanism includes three groups, which are evenly distributed circumferentially and fixed on the fixed base 3. The three ropes 13 controlled by them are respectively led out from the bottom to the top from under the three base rope holes 301 evenly distributed circumferentially on the fixed base 3, and introduced from the bottom to the top along the circumference of the flexible control support body into the three platform rope holes 101 evenly distributed circumferentially on the terminal motion platform 1, and fixed on the terminal motion platform 1; the flexible control support body is controlled to bend by pulling the three ropes, and the terminal motion platform 1 moves accordingly.

[0085] Preferably, the joint traction mechanism includes a traction rope-driven servo 4, a reel 8 and a rope 13; the reel 8 is installed on the traction shaft of the traction rope-driven servo 4, one end of the rope 13 is fixedly wound on the reel 8, and the other end is led out from the bottom to the top from the bottom of the base rope through hole 301 and along the outer periphery of the flexible control support body from the bottom to the top through a platform rope through hole 101, and is fixed on the end motion platform 1.

[0086] Correspondingly, through the mapping relationship established between the length of the traction rope and the end posture of the rope-traction flexible robot joint, the length of the traction rope can be changed with the help of the joint traction mechanism, thereby changing the bending posture of the robot joint to achieve the desired posture, realizing the motion control of the variable stiffness rope-traction flexible robot joint.

[0087] An embodiment of the present invention further provides a processing device, comprising:

[0088] at least one memory for storing one or more programs;

[0089] At least one processor can execute one or more programs stored in the memory, and when the one or more programs are executed by the processor, the processor can implement the above method.

[0090] The embodiments of the present invention further provide a readable storage medium storing a computer program, which can implement the above method when executed by a processor.

[0091] In summary, the control method of the embodiment of the present invention performs motion control on the joints of the variable stiffness rope-traction flexible robot based on the constant curvature model, and derives the mapping relationship between the traction rope length, joint angle, and end pose matrix through geometric relationships. This model takes into account both solution accuracy and computational efficiency and has good practicality.

[0092] In order to more clearly demonstrate the technical solution and technical effects provided by the present invention, the solution provided by the embodiment of the present invention is described in detail with reference to specific embodiments below.

[0093] Example 1

[0094] like Figure 1 As shown, the embodiment of the present invention provides an automatic motion control method for a flexible robot joint pulled by a variable stiffness rope, which is used to control the flexible robot joint (see Figure 3 The mapping relationship between the traction rope length and the terminal pose matrix is ​​solved. This solution method can be applied to the kinematic planning and kinematic control of the joints of a flexible robot with variable stiffness rope traction, and can realize the automatic motion control of the joints of a flexible robot with variable stiffness rope traction, and realize the execution of operation tasks in complex environments. The method includes the following steps:

[0095] Step 1: Set the coordinate system of the variable stiffness rope-traction flexible robot joint fixed base and the end motion platform, and determine the rope length and joint angle variable representation according to the set coordinate system:

[0096] like Figure 2 As shown, the flexible control support can be It means that based on the constant curvature beam assumption, The arc length is a constant value, set as The intersection points of the three traction ropes of the flexible robot joint and the bottom disk plane of the flexible control support are 、 and , and the intersection points with the plane of the end disk are 、 and , the center of the bottom disk plane is , the center of the end disk plane is . Base coordinate system Set at the bottom center of the flexible control support body, The axis is perpendicular to the bottom disk plane, The axis points from the center of the circle to the intersection of the traction rope 1 and the bottom disc plane For the end tool coordinate system , The axis is perpendicular to the plane of the end disk, The axis points from the center of the end disk to the intersection of the first traction rope and the end disk plane .

[0097] When the length of the three traction ropes changes, the support body is flexibly adjusted It will show the motion characteristics of bending to one side. Obviously, the normal vector of the end disk plane, that is, Axis, and flexible control support At the end The tangent vectors at coincide with each other, so and axis, The axes together form a bending plane ,in is the intersection of the bending plane and the bottom disk plane, is the intersection of the bending plane and the end motion disk, and The intersection is Therefore, the rotation angle of the bending plane can be expressed as It is called the bending azimuth ; The plane bending angle of the bending plane can be used , called the bending angle Based on the constant curvature beam assumption, Is a constant value Therefore, the joint motion of the robot pulled by three ropes can be described as a two-degree-of-freedom bending motion, which is determined by the bending azimuth angle. and bending angle These two angles are described.

[0098] The length of the three traction ropes Can be used The length of The values ​​are 1, 2 and 3. A traction rope can be expressed as:

[0099] (1);

[0100] in,

[0101] (2);

[0102] in, Indicates winding Coordinate axis rotation bending angle The rotation matrix of Indicates winding Coordinate axis rotation bending azimuth The rotation matrix of represents the radius of the disk (the distance from the rope lead-out hole to the center of the disk), that is, The distance, that is distance, express Around Rotate counterclockwise to angle, and The relationship is expressed as:

[0103] (3);

[0104] From this, the bending azimuth can be obtained and bending angle With three traction rope lengths The mapping relationship between them:

[0105] (4);

[0106] Step 2: Complete the forward kinematics solution based on the geometric relationship and constant curvature model:

[0107] For the base coordinate system To the end tool coordinate system The homogeneous transformation matrix , the general form is:

[0108] (5);

[0109] in, Indicates the coordinate system from the base To the end tool coordinate system The rotation transformation matrix, Represents the coordinate system To coordinate system The displacement vector of . Figure 2 So, the displacement vector Can be represented as a vector :

[0110] (6);

[0111] The rotation transformation matrix The ZYZ Euler angle method can be used to calculate the bending azimuth and bending angle Derivation:

[0112] (7);

[0113] In the above formulas (6) and (7), s represents sin and c represents cos. Combining formula (7), we can get the lengths of the three traction ropes: and bending azimuth and bending angle And the mapping relationship of the pose matrix to complete the forward kinematics solution.

[0114] Step 3: Complete the inverse kinematics solution through mathematical derivation:

[0115] Three traction rope lengths and bending azimuth and bending angle The mapping relationship between them:

[0116] (8);

[0117] Combining formula (7) we can get the pose matrix and bending azimuth and bending angle and the length of the three traction ropes The mapping relationship is used to complete the inverse kinematics solution.

[0118] Step 4: Complete motion control through mapping relationship:

[0119] By deriving the mapping relationship between the joint position and posture of the rope-traction flexible robot and the length of the traction rope, with the help of the traction rope driving mechanism, that is, the servo-reel-traction rope mechanism, the change of the traction rope length can drive the rotation of the reel 8 through the rotation of the servo 4, thereby realizing the pulling and traction of the rope and completing the motion control of the joint of the rope-traction flexible robot.

[0120] Specifically, the change in the length of the traction rope divided by the radius of the drum 8 is used to obtain the corresponding servo rotation angle, thereby realizing the motion control of the rope traction robot joint.

[0121] In the above method, the variable stiffness rope-driven flexible robot joint is as follows Figures 3 to 5 As shown, it includes an end motion platform 1, a flexible control support body, a joint traction mechanism, a variable stiffness traction servo 10 and a fixed base 3; the lower end of the flexible control support body is connected to the fixed base 3, and the upper end is connected to the end motion platform 1; the flexible control support body includes a flexible support sleeve assembly 6 and a movable support ring shaft assembly 9; the flexible support sleeve assembly 6 is nested outside the movable support ring shaft assembly 9 and connected to form a flexible control support body, and the variable stiffness traction servo 10 is installed at the center of the fixed base 3, connecting and pulling the flexible support sleeve assembly 6 and the movable support ring shaft assembly 9 to rotate relative to each other to change the stiffness of the flexible control support body; the joint traction mechanism is installed on the fixed base 3, and pulls the end motion platform 1 through a rope to drive the flexible control support body to bend, thereby realizing the bending movement of the joint robot. This embodiment can realize active stiffness control through the structural design of the flexible control support body inside the joint, without changing the external environmental conditions, thereby realizing the control of joint stiffness.

[0122] In this embodiment, Figures 6 to 8 As shown, the flexible control support body includes a flexible support sleeve assembly 6 and a movable support ring shaft assembly 9. The flexible support sleeve assembly 6 and the movable support ring shaft assembly 9 are both made of flexible materials. The flexible materials have good plasticity and deformation properties and can be deformed under the action of external forces. Its main characteristics are softness, lightness, good elasticity, and large deformation capacity. Common flexible materials include rubber, plastic, etc. In this example, polyurethane elastomers, silicone, etc. can be used. Polyurethane elastomers, also known as thermoplastic polyurethane elastomers (TPU), are a type of elastomer that can be plasticized by heating and dissolved by solvents. They have excellent comprehensive properties such as high strength, high toughness, wear resistance, and oil resistance. They have good processing performance and are widely used in defense, medical, food and other industries. They are produced by processing methods such as injection molding, extrusion, and blow molding.

[0123] The lower end of the flexible control support body is connected to the fixed base 3, and the upper end is connected to the terminal motion platform 1; the flexible control support body includes a flexible support sleeve assembly 6 and a movable support ring shaft assembly 9; the flexible support sleeve assembly 6 is nested outside the movable support ring shaft assembly 9 and connected to form a flexible control support body, and the variable stiffness traction servo 10 is installed at the center of the fixed base 3, connecting and pulling the flexible support sleeve assembly 6 and the movable support ring shaft assembly 9 to rotate relative to each other to change the stiffness of the flexible control support body.

[0124] The joint traction mechanism is installed on the fixed base 3, and pulls the terminal motion platform 1 through the rope to drive the flexible control support body to bend, thereby realizing the movement of the joint robot.

[0125] Preferably, the flexible support sleeve assembly 6 is a sleeve structure, and at least one sleeve support ring is provided in the inner hole of the sleeve; the sleeve support ring includes more than three fan-shaped sleeve support columns 61 uniformly distributed in the circumferential direction;

[0126] The movable support ring shaft assembly 9 includes a movable flange 91 and a core column 92. The lower end of the core column 92 is fixed to the center of the movable flange 91. The circumference of the core column 92 is provided with at least one layer of core column support ring on the movable flange 91; the core column support ring includes more than three fan-shaped core column support columns 93 uniformly distributed circumferentially; the upper end of the core column 92 extends into the center hole formed by the inner arc surface of the sleeve support column 61; the sleeve support column 61 and the core column support column 93 are spaced apart and the end faces contact each other to support the flexible support sleeve assembly 6;

[0127] The lower end of the flexible support sleeve assembly 6 is connected to the fixed base 3, and the upper end is connected to the terminal motion platform 1; the variable stiffness traction servo 10 is connected and pulls the movable support ring shaft assembly 9 to rotate relative to the flexible support sleeve assembly 6, adjusting the contact area between the end faces of the sleeve support column 61 and the core column support column 93, and changing the stiffness of the flexible control support body.

[0128] Preferably, the sleeve of the flexible support sleeve assembly 6 includes two layers of sleeve support rings, the sleeve support columns 61 of the upper layer are fixed to the inner wall and / or bottom surface of the sleeve; the sleeve support columns 61 of the lower layer are fixed to the inner wall of the sleeve;

[0129] The movable support ring shaft assembly 9 and the core column 92 are provided with two layers of core column support rings around their circumferences. The core column support columns 93 of the upper layer are fixed to the outer wall of the core column 92; the core column support columns 93 of the lower layer are fixed to the outer wall of the core column 92 and / or the end face of the movable flange 91;

[0130] The axial spacing between the two layers of sleeve support columns 61 is the same as the axial height of the core column support column 93 of the upper layer, and the core column support column 93 of the upper layer is arranged between the two layers of sleeve support columns 61;

[0131] The axial spacing between the two layers of core column support columns 93 is the same as the axial height of the sleeve support columns 61 of the next layer, and the sleeve support columns 61 of the next layer are arranged between the two layers of core column support columns 93;

[0132] The end faces of the sleeve support column 61 and the core column support column 93 , which are arranged at intervals, contact each other to support the flexible support sleeve assembly 6 .

[0133] Preferably, the cross-sectional dimensions of the fan-shaped gaps between the adjacent sleeve support columns 61 of the next layer are adapted to the cross-sectional dimensions of the core column support columns 93 of the previous layer, and the core column support columns 93 of the previous layer pass through the fan-shaped gaps to between the two layers of sleeve support columns 61.

[0134] Preferably, the sleeve of the flexible support sleeve assembly 6 includes a sleeve support ring, and the sleeve support column 61 is fixed to the inner wall and / or bottom surface of the sleeve;

[0135] The movable support ring shaft assembly 9 and the core column 92 are provided with a layer of core column support ring around their circumferences, and the core column support column 93 is fixed to the outer wall of the core column 92 and / or the end face of the movable flange 91;

[0136] The end faces of the sleeve support column 61 and the core column support column 93 contact each other to support the flexible support sleeve assembly 6.

[0137] Preferably, the variable stiffness traction servo 10 is connected to the movable flange 91 via a rigid connection flange 12 and pulls the movable support ring shaft assembly 9 to rotate.

[0138] Preferably, the joint traction mechanism includes three groups, which are evenly distributed circumferentially and fixed on the fixed base 3. The three ropes 13 controlled by them are respectively led out from the bottom to the top from under the three base rope holes 301 evenly distributed circumferentially on the fixed base 3, and introduced from the bottom to the top along the circumference of the flexible control support body into the three platform rope holes 101 evenly distributed circumferentially on the terminal motion platform 1, and fixed on the terminal motion platform 1; the flexible control support body is controlled to bend by pulling the three ropes, and the terminal motion platform 1 moves accordingly.

[0139] Preferably, the joint traction mechanism includes a traction rope traction servo 4, a reel 8 and a rope 13; the reel 8 is installed on the traction shaft of the traction rope traction servo 4, one end of the rope 13 is fixedly wound on the reel 8, and the other end is led out from the bottom to the top from the bottom of the base rope through hole 301 and along the outer periphery of the flexible control support body from the bottom to the top through a platform rope through hole 101, and is fixed on the end motion platform 1.

[0140] Correspondingly, through the mapping relationship established between the length of the traction rope and the end posture of the rope-traction flexible robot joint, the length of the traction rope can be changed with the help of the joint traction mechanism, thereby changing the bending posture of the robot joint to achieve the desired posture, realizing the motion control of the variable stiffness rope-traction flexible robot joint.

[0141] In summary, for the motion control of the flexible robot joints pulled by variable stiffness ropes, based on the constant curvature model, the mapping relationship between the traction rope length, joint angle, and end pose matrix is ​​derived through geometric relationships. This model takes into account both solution accuracy and computational efficiency and has good practicality.

[0142] Those skilled in the art will appreciate that all or part of the processes in the above-described method embodiments can be implemented by instructing related hardware through a program. The program can be stored in a computer-readable storage medium. When executed, the program can include the processes in the above-described method embodiments. The storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

[0143] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims. The information disclosed in the background technology section of this article is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or any form of implication that the information constitutes prior art already known to those skilled in the art.

Claims

1. A method for automatically controlling the joint motion of a rope-pulled flexible robot, for automatically controlling the joint motion of a rope-pulled flexible robot comprising an end motion platform (1), a flexible control support, a joint traction mechanism, a variable stiffness traction servo (10) and a fixed base (3), characterized in that: include: Step 1: Set the coordinate system of the variable stiffness rope-traction flexible robot joint fixed base and the end motion platform, and determine the rope length and joint angle variable representation according to the set coordinate system; Step 2: Based on the determined rope length and joint angle variables, complete the forward kinematics solution of the variable stiffness rope traction flexible robot joint according to the geometric relationship and constant curvature model, including: base coordinate system To the end tool coordinate system The homogeneous transformation matrix The general form is: （5）； in, Indicates the coordinate system from the base To the end tool coordinate system The three-dimensional rotation transformation matrix of Represents the base coordinate system to the end tool coordinate system The displacement vector Represented as a vector : （6）； The three-dimensional rotation transformation matrix With the help of ZYZ Euler angle method, the bending azimuth and bending angle The derivation is: （7）； In the above formulas (6) and (7), s represents sin and c represents cos; Combining formula (7) can get the length of the three traction ropes and bending azimuth and bending angle And the mapping relationship between the position and pose matrix is ​​used to complete the forward kinematics solution of the variable stiffness rope-traction flexible robot joint; Step 3: Based on the forward kinematics solution, the inverse kinematics solution of the variable stiffness rope traction flexible robot joint is completed through mathematical derivation; Step 4: Automatically control the motion of the variable stiffness rope traction flexible robot joints based on the mapping relationship between the traction rope length and the terminal pose matrix determined by the inverse kinematics solution.

2. The automatic motion control method of the rope-driven flexible robot joint according to claim 1 is characterized in that: In step 1, the coordinate systems of the variable stiffness rope-traction flexible robot joint fixed base and the terminal motion platform are set in the following manner, including: The flexible control support body of the flexible robot joint pulled by the variable stiffness rope is used as a curve express; The intersection points of the three traction ropes of the variable stiffness rope traction flexible robot joint and the bottom disk plane of the flexible control support are 、 and , and the intersection points with the plane of the end disk are 、 and , the center of the bottom disk plane is , the center of the end disk plane is ; Base coordinate system Set at the bottom center of the flexible control support body, The axis is perpendicular to the bottom disk plane, The axis points from the center of the circle to the intersection of the first traction rope and the bottom disc plane ; For the end tool coordinate system , The axis is perpendicular to the plane of the end disk, The axis points from the center of the end disk to the intersection of the first traction rope and the end disk plane ; When the length of the three traction ropes changes, the support body is flexibly adjusted It will show the motion characteristics of bending to one side, and the normal vector of the end disk plane is Axis, and flexible control support At the end The tangent vectors at coincide with each other, that is, and axis, The axes together form a bending plane ,in is the intersection of the bending plane and the bottom disk plane, is the intersection of the bending plane and the end motion disk, and The intersection is ; The rotation angle of the bending plane is expressed as It is called the bending azimuth ; The plane bending angle of the bending plane is expressed as , called the bending angle ; Based on the constant curvature beam assumption, Is a constant value , the joint motion of the flexible robot with variable stiffness pulled by three ropes is determined by the bending azimuth angle and bending angle These two angles describe the two degrees of freedom of bending motion.

3. The automatic motion control method of the rope-driven flexible robot joint according to claim 2 is characterized in that: In step 1, the variable representation of the rope length and the joint angle is determined according to the set coordinate system in the following manner, including: The lengths of the three traction ropes of the flexible robot joint with variable stiffness rope traction use The length of The values ​​are 1, 2, and 3. The length of the traction rope is expressed as: （1）； in, （2）； in, Indicates winding Coordinate axis rotation bending angle The rotation matrix of Indicates winding Coordinate axis rotation bending azimuth The rotation matrix of Indicates the radius of the disk, that is, the distance between the traction rope lead-out hole and the center of the disk, that is The distance, that is The superscript T represents the transpose of the matrix; express Around Rotate counterclockwise to Angle, and bending azimuth The relationship is expressed as: （3）； Get the bending azimuth and bending angle With three traction rope lengths The mapping relationship between them is: （4）。 4. The automatic motion control method of the rope-driven flexible robot joint according to claim 1 is characterized in that: In step 3, the inverse kinematics solution of the variable stiffness rope traction flexible robot joint is completed by mathematical derivation based on the forward kinematics solution result in the following manner, including: Three traction rope lengths and bending azimuth and bending angle The mapping relationship between them is: （8）； Combining Equation (8) with Equation (7) yields the pose matrix and bending azimuth and bending angle and the length of the three traction ropes The mapping relationship is used to complete the inverse kinematics solution of the variable stiffness rope-traction flexible robot joints.

5. The automatic motion control method for a rope-driven flexible robot joint according to any one of claims 1 to 3, characterized in that: In step 4, the variable stiffness rope traction flexible robot joint is automatically controlled in the following manner according to the mapping relationship between the traction rope length and the terminal posture matrix determined by the inverse kinematics solution result, including: According to the mapping relationship between the position and posture of the joint of the variable stiffness rope traction flexible robot and the length of the traction rope, the traction rope length is changed by pulling the traction rope driving mechanism, and the bending posture of the joint of the variable stiffness rope traction flexible robot is changed to achieve the desired posture, thereby realizing automatic motion control of the joint of the variable stiffness rope traction flexible robot.

6. The automatic motion control method for a rope-driven flexible robot joint according to any one of claims 1 to 3, characterized in that: In the method, in the controlled variable stiffness rope-traction flexible robot joint, the lower end of the flexible control support is connected to the fixed base (3), and the upper end is connected to the terminal motion platform (1); The flexible control support body comprises a flexible support sleeve assembly (6) and a movable support ring shaft assembly (9), wherein the flexible support sleeve assembly (6) is nested outside the movable support ring shaft assembly (9) and connected to form a flexible control support body structure; The variable stiffness traction steering gear (10) is installed at the center of the fixed base (3), and is connected to and pulls the flexible support sleeve assembly (6) and the movable support ring shaft assembly (9) to rotate relative to each other to change the stiffness of the flexible control support body; The joint traction mechanism is mounted on a fixed base (3), and pulls the terminal motion platform (1) via a traction rope, thereby driving the flexible control support to bend, thereby achieving a bending movement of the flexible robot joint pulled by a variable stiffness rope.

7. The automatic motion control method of the rope-driven flexible robot joint according to claim 6 is characterized in that: The flexible support sleeve assembly (6) and the movable support ring shaft assembly (9) are both made of flexible materials; The lower end of the flexible support sleeve assembly (6) is connected to the fixed base (3), and the upper end is connected to the terminal motion platform (1); The flexible support sleeve assembly (6) is a sleeve structure, and at least one sleeve support ring is provided in the inner hole of the sleeve; the sleeve support ring includes more than three fan-shaped sleeve support columns (61) uniformly distributed in the circumferential direction; The movable support ring shaft assembly (9) includes a movable flange (91) and a core column (92), the lower end of the core column (92) is fixed to the center of the movable flange (91), and the core column (92) is provided with at least one layer of core column support ring on the movable flange (91) on the circumference; the core column support ring includes more than three fan-shaped core column support columns (93) uniformly distributed in the circumferential direction; The upper end of the core column (92) extends into the central hole formed by the inner arc surface of the sleeve support column (61); The sleeve support column (61) and the core column support column (93) are spaced apart and their end faces contact each other to support the flexible support sleeve assembly (6); The variable stiffness traction steering gear (10) is connected to and pulls the movable support ring shaft assembly (9) to rotate relative to the flexible support sleeve assembly (6), thereby adjusting the contact area between the end faces of the sleeve support column (61) and the core column support column (93), and changing the stiffness of the flexible control support body.

8. A processing device, characterized in that include: at least one memory for storing one or more programs; At least one processor is capable of executing one or more programs stored in the memory, and when the one or more programs are executed by the processor, the processor is capable of implementing the method according to any one of claims 1 to 7.

9. A readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 can be implemented.

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