A valve assembly robot with adjustable posture and use method thereof

Abstract

The present invention belongs to the technical field of industrial robots, and specifically relates to a valve assembly robot with adjustable posture and a method of using the same. The valve assembly robot of the present invention comprises a base plate, a three-degree-of-freedom parallel mechanism installed on the base plate, a moving platform rotatably connected to the output end of the three-degree-of-freedom parallel mechanism, a positioning and clamping device and an upper support clamping device installed on the moving platform for positioning and clamping the valve body to be assembled, and a manipulator arranged on the ground for clamping and installing the upper support of the valve body to be assembled. When the valve assembly robot of the present invention assembles the upper support of the valve onto the valve body, a three-degree-of-freedom parallel mechanism is designed to adjust the posture of the valve body, so that the valve body and the upper support of the valve can be accurately aligned in terms of hole position, and the manipulator is used to place the upper support of the valve and tighten the screws, thereby solving the problem of medium leakage caused by assembly errors between the valve body and the upper support of the valve in the prior art and extending the service life of the valve.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial robots, and in particular relates to a valve assembly robot with adjustable posture and a use method thereof. Background Art

[0002] A valve generally includes a valve body and a valve support installed on the valve body. It is mostly used in water supply, heating and gas supply systems. It is a common device for controlling the flow of gas or liquid in a pipeline.

[0003] In the prior art, the valve assembly process is mostly carried out purely manually or with mechanical assistance. The upper support of the valve is moved manually or the positioning and tightening device is carried by auxiliary tooling, the upper support of the valve is moved to the valve body, and the screws are manually screwed to fix the upper support of the valve to the valve body. This assembly method has a high risk factor for personal safety and has low assembly efficiency and assembly accuracy. In addition, manual assembly has large assembly errors. It is difficult to accurately align the hole position of the support on the valve with the corresponding hole position of the valve body. During the use of the valve, the sealing is not high and the medium leakage is prone to occur. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects in the prior art such as low assembly efficiency, difficulty in accurately aligning the support holes on the valve with the corresponding valve body holes, resulting in low sealing, and to provide a valve assembly robot with adjustable posture that can adjust the posture of the valve block and accurately position the support holes on the valve, and a method for using the same.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] As a first aspect, a posture-adjustable valve assembly robot comprises a base plate, a three-degree-of-freedom parallel mechanism mounted on the base plate, a moving platform rotatably connected to an output end of the three-degree-of-freedom parallel mechanism, a positioning and clamping device and an upper support clamping device mounted on the moving platform for positioning and clamping a valve body to be assembled, and a manipulator disposed on the ground for clamping and installing an upper support of the valve body to be assembled;

[0007] The three-degree-of-freedom parallel mechanism comprises three posture adjustment components with the same structure, namely a first posture adjustment component, a second posture adjustment component and a third posture adjustment component; the first posture adjustment component and the second posture adjustment component are symmetrically arranged, and both are perpendicular to the third posture adjustment component in a horizontal plane;

[0008] The posture adjustment assembly comprises: a base fixedly mounted on the base plate;

[0009] A fixed-length restraint chain assembly, one end of which is rotatably connected to the base, and the other end of which is rotatably connected to the moving platform;

[0010] A driving branch chain assembly, wherein the driving branch chain assembly changes the distance of the moving platform relative to the base plate in the vertical direction; the fixed end of the driving branch chain assembly is rotatably connected to the base plate, and the telescopic end thereof is rotatably connected to the moving platform;

[0011] The position and posture of the valve body to be assembled on the moving platform are adjusted through the displacement changes of the three driving branch chain assemblies and the constraints of the three fixed-length constraint chain assemblies; in the initial state, the fixed ends of the three driving branch chain assemblies are arranged to form a triangular structure, and the extension and retraction directions of the three driving branch chain assemblies are perpendicular to the base plate; the plane formed by the three fixed-length constraint chain assemblies in space is on the horizontal plane.

[0012] Furthermore, the moving platform is in a triangular structure, and the fixed-length constraint chain assembly includes a fixed-length constraint rod having one end rotatably connected to the base via a joint bearing and the other end rotatably mounted to the vertex of the moving platform via a joint bearing.

[0013] Furthermore, the drive branch chain assembly comprises:

[0014] A driving hydraulic cylinder, the fixed end of which is rotatably mounted on the base through a lower support assembly, and the telescopic end of the driving hydraulic cylinder is rotatably mounted on the vertex of the moving platform through an upper support assembly;

[0015] The first proportional servo valve is installed on the driving hydraulic cylinder and is used to adjust the flow of the driving hydraulic cylinder.

[0016] Furthermore, the driving displacement calculation of the driving branch chain assembly specifically includes:

[0017] The driving displacement calculation of the three driving branch chain components specifically includes:

[0018] With the center of the moving platform as the origin O, the moving platform motion coordinate system (X P , Y P , Z P ); take the center of the bottom plate as the origin O1, and set the platform coordinate system (X L , Y L , Z L ); the fixed platform coordinate system is parallel to the Cartesian coordinate system (x, y, z);

[0019] The kinematic analysis of the three-degree-of-freedom parallel stabilized platform is performed to obtain the motion spiral system S as follows:

[0020]

[0021] Where P z represents the movement of the moving platform along the z-axis, R xrepresents the rotation of the moving platform around the x-axis, R y Indicates the rotation of the moving platform around the y-axis;

[0022] According to the above-mentioned motion spiral system, the three-degree-of-freedom parallel mechanism includes a vertical swing movement degree of freedom, a roll rotation degree of freedom and a pitch rotation degree of freedom, and the vertical swing movement degree of freedom is the movement along the z-axis. z The roll and pitch degrees of freedom are the rotation θ of the moving platform around the x and y axes respectively. x =γ、θ y =β;

[0023] Establish the constraint equation according to the position of the fixed-length constraint rod:

[0024]

[0025] In the formula, l m Indicates the length of the fixed-length restraint rod, F i (i=1,2,3),D i (i=1,2,3) are the center points of the joint bearings connecting the fixed-length constraint rod and the moving platform and the fixed platform, respectively. Their positions in the fixed platform coordinate system are (F ix , F iy , F iz )、(D ix , D iy , D iz ).

[0026] The inverse kinematics of the parallel mechanism is combined with the above constraint equations to solve the displacement of the three drive branch chain components:

[0027] According to the known position and posture of the moving platform, solve the three input lengths of the drive branch chain components (l1, l2, l3):

[0028]

[0029] In the formula, R a R represents the radius of the circumscribed circle of the hinge point of the moving platform. b represents the radius of the circumscribed circle of the fixed platform hinge point, η i (i=1, 2, 3) represents the angle between each hinge point and the x-axis, H is the initial vertical distance between the moving platform and the fixed platform, r ij Represents the moving coordinate system (X P , Y P , Z P ) relative to the fixed coordinate system (X L , Y L , Z L )Rotation transformation matrix The corresponding value of the i-th row and j-th column in is, η irepresents the angle between each hinge point and the x-axis, where i=1,2,3;

[0030] The telescopic displacement of the hydraulic rod corresponding to the driving hydraulic cylinder is obtained by subtracting the initial length of the driving branch chain assembly from the length of the driving branch chain assembly solved above.

[0031] According to the known position and posture of the moving platform, the three input lengths of the drive branch chain components (l1, l2, l3) are solved, which specifically includes the following calculations:

[0032] Step 1: Construct a moving coordinate system (X P , Y P , Z P ) relative to the fixed coordinate system (X L , Y L , Z L ) is the rotation matrix of It consists of three RPY angles γ, β and α, which rotate around the x-axis, y-axis and z-axis in the Cartesian coordinate system (x, y, z), respectively. Here, the x-axis, y-axis and z-axis are respectively related to the fixed coordinate system (X L , Y L , Z L ) where the x-axis, y-axis, and z-axis are parallel, the transformation matrix is ​​expressed as:

[0033]

[0034] Wherein, s represents sin, and c represents cos.

[0035] Step 2: Set the hinge point B between the moving platform and the drive branch chain assembly i The coordinates of the bottom plate, i.e. the moving platform, and the hinge point A of the drive branch chain assembly are set at the same time. i The coordinates of

[0036] As an implementation method, the moving platform 13 and the corresponding bottom plate, i.e., the fixed platform, are both equilateral triangles, and the central angle θ corresponding to each side is a =θ b =2п / 3; where the hinge point A i In the fixed coordinate system (X L , Y L , Z L ) is a i , hinge point B i In the moving coordinate system (X P , Y P , Z P ) is the coordinate b i , its mathematical expression is:

[0037] a i =[R a cosη i Ra sinη i 0]

[0038] b i =[R b cosη i R b sinη i 0]

[0039] η i =2π(i-3) / 3+π / 2, i=1, 2, 3

[0040] In the formula, R a R represents the radius of the circumscribed circle of the hinge point of the moving platform. b represents the radius of the circumscribed circle of the fixed platform hinge point, η i (i=1, 2, 3) represents the angle between each hinge point and the x-axis;

[0041] Step 3, calculate the length vector of the drive branch chain assembly, the specific calculation is as follows: Determine the platform U sub-center point A i In the fixed coordinate system (X L , Y L , Z L ) is the position vector L A i for:

[0042] L A i =(A ix A iy A iz ) T ;

[0043] Center position B of the auxiliary ball joint of the moving platform S i In the moving coordinate system (X P , Y P , Z P ) is the position vector P B i for:

[0044] P B i =(B ix B iy B iz ) T ;

[0045] The origin O of the moving coordinate system is in the moving coordinate system (X P , Y P , Z P ) in the fixed coordinate system (X L , Y L , Z L ) is the position vectorL O P for:

[0046] L O P =( L O Px L O Py L O Pz ) T =(xy z+H) T ;

[0047] In the formula, H represents the initial vertical distance between the moving platform and the fixed platform;

[0048] The length vector of the i-th drive branch chain component is:

[0049]

[0050] Further, the upper support clamping device includes a clamping base fixedly mounted on the movable platform, an adjustable bracket slidably arranged on the clamping base through a vertical sliding module, a clamping hydraulic cylinder mounted on the adjustable bracket, an upper clamping arm rotatably connected to the telescopic end of the clamping hydraulic cylinder through a swivel pin, an upper pressure plate connected to the output end of the upper clamping arm, and a second proportional servo valve mounted on the clamping hydraulic cylinder for controlling the flow of the clamping hydraulic cylinder;

[0051] The upper clamping arm includes an active rod and a driven rod arranged in parallel on the adjustable bracket, and a small arm driving rod rotatably connected to the ends of the active rod and the driven rod; the telescopic end of the clamping hydraulic cylinder is rotatably connected to the active rod through a swivel pin, and the upper pressure plate is fixedly mounted at the end of the small arm driving rod.

[0052] Furthermore, the positioning and tightening device comprises two positioning and tightening mechanisms symmetrically arranged on the moving platform, namely a left positioning and tightening mechanism and a right positioning and tightening mechanism;

[0053] The positioning and clamping mechanism includes a side positioning base fixedly installed on the moving platform, a six-jaw chuck base slidably installed on the side positioning base through a horizontal moving module, and a six-jaw chuck module installed on the six-jaw chuck base; the horizontal moving module on the left positioning and clamping mechanism and the horizontal moving module on the right positioning and clamping mechanism drive the six-jaw chuck module to fix and position the valve body to be assembled.

[0054] Further, the manipulator includes a chassis fixedly arranged on the ground or placed on a platform, a shoulder mechanism rotatably mounted on the chassis, an upper arm mechanism, an elbow joint mechanism, a lower arm mechanism, a wrist mechanism and a manipulator tool module which are rotatably mounted with the shoulder mechanism in sequence;

[0055] The manipulator tool module comprises a pneumatic clamp mounted on the actuator conversion mechanism and an electric screwdriver fixedly mounted on the actuator conversion mechanism via a connecting seat.

[0056] Furthermore, it also includes a data acquisition module and a control module for analysis and control;

[0057] The data acquisition module includes a first force sensor installed on the positioning and clamping device, a second force sensor installed on the upper support and clamping device, and a visual sensor installed on the upper support and clamping device; the first force sensor is used to detect the opening force data of the six-jaw chuck module, and the control module receives the opening force data and compares it with a predetermined value to determine whether the valve body is in a clamped and fixed state on the moving platform; the second force sensor is used to collect the pressure value of the upper support and clamping device acting on the upper support of the valve body; the visual sensor is used to collect image information in real time, and the control module receives the image information to determine whether the end of the manipulator is aligned with the hole position of the valve body to be assembled.

[0058] As a second aspect, according to the above-mentioned method for using a posture-adjustable valve assembly robot, the method comprises the following steps:

[0059] A1. Lift the valve body to be assembled onto the moving platform;

[0060] A2. Pre-fix the valve body to be assembled; that is, start the horizontal moving modules on the left positioning and tightening mechanism and the right positioning and tightening mechanism to drive the six-jaw chuck base to move toward the valve body to be assembled, until the left positioning and tightening mechanism and the right positioning and tightening mechanism are in contact with the valve body to be assembled, and the horizontal moving module is self-locking;

[0061] A3. Tighten and fix the valve body to be assembled; that is, start the six-jaw chuck module to drive the jaws to open, and when the value measured by the first force sensor reaches a predetermined value, the six-jaw chuck module self-locks, and the valve body to be assembled is in a tightened and fixed state on the moving platform;

[0062] A4. Adjust the hole positions of the valve body to be assembled and the upper support of the valve; that is, the manipulator grasps the upper support of the valve and moves it to the top of the mounting surface of the valve body. The control module controls the movement of the three-degree-of-freedom parallel mechanism to adjust the position of the valve body to be assembled by receiving the image information collected in real time by the visual sensor, until the valve body to be assembled is aligned with the corresponding hole position of the upper support of the valve;

[0063] A5. Press and assemble the upper support of the valve and the valve body to be assembled; start the upper support pressing device to press the upper support of the valve and the valve body to be assembled, rotate the manipulator, and use the electric screwdriver to pre-tighten and tighten the screws on the upper support of the valve and the valve body to be assembled;

[0064] A6. Valve exit and initialization operation.

[0065] Specifically, the valve exit and initialization operation specifically includes the following steps:

[0066] A601. The manipulator rotates to the initial position;

[0067] A602. The upper support clamping device is separated from the valve and rotated back to the initial position;

[0068] A603. Control the three-degree-of-freedom parallel mechanism to level the moving platform, start the horizontal moving module of the positioning and tightening device to move away from the valve, so that the valve is in a movable state;

[0069] A604. Move the valve to the designated location using lifting equipment.

[0070] The beneficial effects of the posture-adjustable valve assembly robot and the use method thereof of the present invention are:

[0071] When assembling the valve upper support to the valve body, the valve assembly robot of the present invention designs a three-degree-of-freedom parallel mechanism to adjust the valve body posture, so that the valve body and the valve upper support can be accurately aligned in hole position, and the valve upper support is placed and screwed by a manipulator, so as to achieve complete alignment of the hole positions between the valve body and the valve upper support, solve the problem of medium leakage caused by assembly error between the valve body and the valve upper support in the prior art, and extend the service life of the valve. The three-degree-of-freedom parallel mechanism of the present invention is provided with three fixed-length constraint chain assemblies and three drive branch chain assemblies. In the initial state, the fixed ends of the three drive branch chain assemblies are surrounded into a triangular structure, and the telescopic directions of the three drive branch chain assemblies are perpendicular to the bottom plate. The plane formed by the three fixed-length constraint chain assemblies in space is on the horizontal plane. The entire three-degree-of-freedom parallel mechanism constitutes a 3UPS / 3SS structure with high speed, high load capacity and no error accumulation. By adjusting the displacement of the three drive branch chain assemblies to drive the moving platform to move, the purpose of adjusting the posture of the valve body to be installed is achieved. The entire structure is compact, flexible and stable, and can meet the assembly requirements of large valves. The danger caused by manual handling during the assembly process is avoided.

[0072] The present invention adopts a six-degree-of-freedom manipulator in conjunction with a three-degree-of-freedom parallel mechanism to assemble the valve, which effectively reduces the working space of the manipulator and improves the efficiency of aligning the support on the valve with the hole position of the valve body. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0074] Figure 1 4 is a three-dimensional diagram of a valve assembly robot according to an embodiment of the present invention.

[0075] Figure 2 Schematic diagram of the structure of a three-degree-of-freedom parallel stabilized platform according to an embodiment of the present invention.

[0076] Figure 3 Schematic diagram of a part of the structure of a three-degree-of-freedom parallel stabilization platform according to an embodiment of the present invention

[0077] Figure 4 It is a schematic structural diagram of a drive branch chain assembly according to an embodiment of the present invention.

[0078] Figure 5 Schematic diagram of the structure of the constraint branch chain assembly according to an embodiment of the present invention.

[0079] Figure 6 This is a calculation diagram of a three-degree-of-freedom parallel stable platform according to an embodiment of the present invention.

[0080] Figure 7 It is a structural schematic diagram of a positioning and tightening mechanism according to an embodiment of the present invention.

[0081] Figure 8 It is a detailed view of the six-jaw chuck module of an embodiment of the present invention.

[0082] Fig. 9 It is a structural schematic diagram of a horizontal moving module according to an embodiment of the present invention.

[0083] Fig.10 It is a schematic structural diagram of an upper support and clamping device according to an embodiment of the present invention.

[0084] Fig.11 Schematic diagram of the structure of the valve according to the embodiment of the present invention.

[0085] Fig.12 Schematic diagram of the structure of the robot according to the embodiment of the present invention.

[0086] Fig.13 It is a flow chart of the method for using the valve assembly robot according to an embodiment of the present invention.

[0087] Fig.14 It is a work flow chart of an embodiment of the present invention.

[0088] Fig.15 Is a control flow chart of an embodiment of the present invention.

[0089] In the figure: 1. three-degree-of-freedom parallel stable platform, 11. bottom plate, 12. three-degree-of-freedom parallel mechanism, 121. first posture adjustment component, 122. second posture adjustment component, 123. third posture adjustment component, 1211. base, 1212. fixed-length constraint chain component, 12121. fixed-length constraint rod, 12122. joint bearing, 1213. drive branch chain component, 12131. drive hydraulic cylinder, 12132. first proportional servo valve, 13. moving platform, 14. positioning and tightening device, 141. positioning and tightening mechanism, 1411. side positioning base, 1412. horizontal moving module, 14121. horizontal servo motor, 14122. horizontal screw nut pair, 14123. horizontal guide rail, 14124. horizontal slider, 1413. six-jaw chuck base, 1414. six-jaw chuck module, 14 141. Clamping claw servo motor, 14142. Clamping claw, 15. Upper support clamping device, 151. Clamping base, 152. Vertical sliding module, 153. Adjustable bracket, 154. Clamping hydraulic cylinder, 155. Rotary pin, 156. Upper clamping arm, 1561. Active rod, 1562. Driven rod, 1563. Forearm driving rod, 157. Upper pressure plate, 158. Second proportional servo valve, 2. Manipulator, 21. Chassis, 22. Shoulder mechanism, 23. Upper arm mechanism, 24. Elbow joint mechanism, 25. Forearm mechanism, 26. Wrist mechanism, 27. Manipulator tool module, 271. Pneumatic clamp, 272. Electric screwdriver, 28. Actuator conversion mechanism, 3. Valve, 31. Valve body to be assembled, 32. Valve upper support, 41. First force sensor, 42. Second force sensor, 43. Visual sensor. DETAILED DESCRIPTION

[0090] The present invention will now be further described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention. It should be known that in mechanism, C stands for cylindrical pair, R stands for revolute pair, P stands for translation pair, S stands for ball pair, U stands for Hooke's joint, and SS refers to a fixed-length connecting rod with ball pairs at both ends, which will not be described in detail later.

[0091] like Figure 1-Figure 12The specific embodiment of the valve assembly robot with adjustable posture of the present invention shown in the figure comprises a three-degree-of-freedom parallel stable platform 1 for placing the valve body 31 to be assembled and a manipulator 2 for clamping and installing the upper support 32 of the valve. The three-degree-of-freedom parallel stable platform 1 comprises a base plate 11, a three-degree-of-freedom parallel mechanism 12 installed on the base plate 11, a moving platform 13 rotatably connected to the output end of the three-degree-of-freedom parallel mechanism 12, and a positioning and tightening device 14 and an upper support and tightening device 15 installed on the moving platform 13 for positioning and pressing the valve body 31 to be assembled. Among them, the three-degree-of-freedom parallel mechanism 12 comprises three posture adjustment components with the same structure, namely, a first posture adjustment component 121, a second posture adjustment component 122 and a third posture adjustment component 123; the first posture adjustment component 121 and the second posture adjustment component 122 are symmetrically arranged, and both are perpendicular to the third posture adjustment component 123 in the horizontal plane.

[0092] In this embodiment, the posture adjustment assembly includes a base 1211 fixedly mounted on the base plate 11, a fixed-length constraint chain assembly 1212 mounted on the base 1211, and a drive branch chain assembly 1213; one end of the fixed-length constraint chain assembly 1212 is rotatably connected to the base 1211, and the other end is rotatably connected to the moving platform 13; the drive branch chain assembly 1213 changes the distance of the moving platform 13 relative to the base plate 11 in the vertical direction; the fixed end of the drive branch chain assembly 1213 is rotatably connected to the base plate 11, and its telescopic end is rotatably connected to the moving platform 13. Through the displacement change of the three drive branch chain assemblies 1213 and the constraints of the three fixed-length constraint chain assemblies 1212, the posture of the valve body 31 to be assembled set on the moving platform 13 is adjusted; in the initial state, the fixed ends of the three drive branch chain assemblies 1213 are surrounded to form a triangular structure, and the telescopic directions of the three drive branch chain assemblies 1213 are perpendicular to the base plate 11; the plane formed by the three fixed-length constraint chain assemblies 1212 in space is on the horizontal plane.

[0093] The posture-adjustable valve assembly robot of the present invention is provided with a three-degree-of-freedom parallel stable platform 1, a manipulator 2, a positioning and tightening device 14 for positioning the valve body, and an upper support clamping device 15 for clamping the valve upper support 32. The chassis 21 of the three-degree-of-freedom parallel stable platform 1 is fixed on the ground or other placement platform, three driving branch chain assemblies 1213 drive the moving platform 13 to move, and three fixed-length constraint branch chain assemblies limit the three degrees of freedom of the moving platform 13 so that it can only move along the z-axis and rotate around the x- and y-axes.

[0094] When the valve assembly robot of the present invention assembles the valve upper support 32 onto the valve body, a three-degree-of-freedom parallel mechanism 12 is designed to adjust the valve body posture so that the valve body and the valve upper support 32 can be accurately aligned in hole position, and the manipulator 2 is used to place the valve upper support 32 and tighten the screws, so as to achieve complete alignment of the hole positions between the valve body and the valve upper support 32, thereby solving the problem of medium leakage caused by assembly error between the valve body and the valve upper support 32 in the prior art and extending the service life of the valve 3.

[0095] like Figure 3 and Figure 5 As shown, in this embodiment, the moving platform 13 is a triangular structure, and the fixed-length constraint chain assembly 1212 includes a fixed-length constraint rod 12121 whose one end is rotatably connected to the base 1211 through a joint bearing 12122, and the other end is rotatably installed with the vertex of the moving platform 13 through the joint bearing 12122.

[0096] like Figure 4 As shown, the driving branch chain assembly 1213 includes a driving hydraulic cylinder 12131 and a first proportional servo valve 12132. The fixed end of the driving hydraulic cylinder 12131 is rotatably mounted on the base 1211 through the lower support assembly, and the telescopic end of the driving hydraulic cylinder 12131 is rotatably mounted through the upper support assembly and the vertex of the moving platform 13. The first proportional servo valve 12132 is installed on the driving hydraulic cylinder 12131 and is used to adjust the flow of the driving hydraulic cylinder 12131.

[0097] Combination Figure 3 and Figure 6 , Figure 6 A1A2A3 represents the bottom plate 11, i.e., the fixed platform, O1 is the center of the fixed platform, B1B2B3 represents the moving platform 13, and O is the center of the moving platform 13. A1B1, A2B2, and A3B3 represent the first drive branch chain assembly 1213, the second drive branch chain assembly 1213, and the third drive branch chain assembly 1213, respectively. C1D1, C2D2, and C3D3 represent the first fixed-length constraint branch chain assembly, the second fixed-length constraint branch chain assembly, and the third fixed-length constraint branch chain, respectively. In the initial state, the plane formed by the three fixed-length constraint branch chain assemblies in space is parallel to the plane formed by the x and y axes of the Cartesian coordinate system, and the driving axes, i.e., the telescopic directions, of the first drive branch chain assembly 1213, the second drive branch chain assembly 1213, and the third drive branch chain are parallel to each other and perpendicular to the bottom plate 11 and the moving platform 13, respectively. The three drive branch chain assemblies 1213 of the present invention are all UPS structures, the P pair is the drive pair, and the three fixed-length constraint branch chain assemblies are all SS structures.

[0098] In this embodiment, the driving displacement calculation of the three driving branch chain components 1213 specifically includes: The driving displacement calculation of the three driving branch chain components 1213 specifically includes:

[0099] With the center of the moving platform 13 as the origin O, the moving platform 13 motion coordinate system (X P , Y P , Z P ); Taking the center of the bottom plate 11 as the origin O1, set the platform coordinate system (X L , Y L , Z L ); The platform coordinate system is parallel to the Cartesian coordinate system (x, y, z);

[0100] The kinematic analysis of the three-degree-of-freedom parallel stabilized platform 1 is performed, and the motion spiral system S is obtained as follows:

[0101]

[0102] Where P z represents the movement of the moving platform 13 along the z-axis, R x represents the rotation of the moving platform 13 around the x-axis, R y represents the rotation of the moving platform 13 around the y-axis;

[0103] According to the above-mentioned motion spiral system, the three-degree-of-freedom parallel mechanism 12 includes a vertical swing degree of freedom, a roll rotation degree of freedom and a pitch rotation degree of freedom. The vertical swing degree of freedom is the movement along the z-axis. z The roll rotational freedom and pitch rotational freedom are respectively the rotation θ of the moving platform 13 around the x and y axes x =γ、θ y =β;

[0104] Establish the constraint equation according to the position of the fixed-length constraint rod 12121:

[0105]

[0106] In the formula, l m Indicates the length of the fixed-length restraint rod 12121, F i (i=1,2,3),D i (i=1,2,3) are the center points of the fixed-length constraint rod 12121, the moving platform 13, and the fixed platform connecting joint bearing 12122, and their positions in the fixed platform coordinate system are (F ix , F iy , F iz )、(D ix , D iy , D iz ).

[0107] The inverse kinematics of the parallel mechanism is combined with the above constraint equations to solve the displacement of the three drive branch chain components 1213:

[0108] According to the known position and posture of the moving platform (13), the length inputs of the three drive branch chain components (l1, l2, l3) are solved:

[0109]

[0110] In the formula, R a R represents the radius of the circumscribed circle of the hinge point of the moving platform. b represents the radius of the circumscribed circle of the fixed platform hinge point, η i (i=1, 2, 3) represents the angle between each hinge point and the x-axis, H is the initial vertical distance between the moving platform and the fixed platform, r ij Represents the moving coordinate system (X P , Y P , Z P ) relative to the fixed coordinate system (X L , Y L , Z L )Rotation transformation matrix The corresponding value of the i-th row and j-th column in is, η i represents the angle between each hinge point and the x-axis, where i=1,2,3;

[0111] The hydraulic rod telescopic displacement corresponding to the driving hydraulic cylinder is obtained by subtracting the initial length of the driving branch chain assembly from the length of the driving branch chain assembly solved above.

[0112] According to the known position and posture of the moving platform 13, the length input quantities (l1, l2, l3) of the three driving branch chain components (1213) are solved, which specifically includes the following calculations:

[0113] Step 1: Construct a moving coordinate system (X P , Y P , Z P ) relative to the fixed coordinate system (X L , Y L , Z L ) is the rotation matrix of It consists of three RPY angles γ, β and α, which rotate around the x-axis, y-axis and z-axis in the Cartesian coordinate system (x, y, z), respectively. Here, the x-axis, y-axis and z-axis are respectively related to the fixed coordinate system (X L , Y L , Z L ) where the x-axis, y-axis, and z-axis are parallel, the transformation matrix is ​​expressed as:

[0114]

[0115] Wherein, s represents sin, and c represents cos.

[0116] Step 2: Set the hinge point B between the moving platform 13 and the drive branch chain assembly 1213 iThe coordinates of the bottom plate, i.e. the moving platform, and the hinge point A of the drive branch chain assembly 1213 are set at the same time. i The coordinates of

[0117] As an implementation method, the moving platform 13 and the corresponding bottom plate, i.e., the fixed platform, are both equilateral triangles, and the central angle θ corresponding to each side is a =θ b =2п / 3; where the hinge point A i In the fixed coordinate system (X L , Y L , Z L ) is a i , hinge point B i In the moving coordinate system (X P , Y P , Z P ) is the coordinate b i , its mathematical expression is:

[0118] a i =[R a cosη i R a sinη i 0]

[0119] b i =[R b cosη i R b sinη i 0]

[0120] η i =2π(i-3) / 3+π / 2, i=1, 2, 3

[0121] In the formula, R a R represents the radius of the circumscribed circle of the hinge point of the moving platform. b represents the radius of the circumscribed circle of the fixed platform hinge point, η i (i=1, 2, 3) represents the angle between each hinge point and the x-axis;

[0122] Step 3, calculate the length vector of the drive branch chain assembly 1213, the specific calculation is as follows: Determine the sub-center point A of the platform U i In the fixed coordinate system (X L , Y L , Z L ) is the position vector L A i for:

[0123] L A i =(A ix A iy A iz )T ;

[0124] Center position B of the auxiliary ball joint of the moving platform S i In the moving coordinate system (X P , Y P , Z P ) is the position vector P B i for:

[0125] P B i =(B ix B iy B iz ) T ;

[0126] The origin O of the moving coordinate system is in the moving coordinate system (X P , Y P , Z P ) in the fixed coordinate system (X L , Y L , Z L ) is the position vector L O P for:

[0127] L O P =( L O Px L O Py L O Pz ) T =(xy z+H) T ;

[0128] Wherein, H represents the initial vertical distance between the moving platform 13 and the fixed platform;

[0129] The length vector of the i-th drive branch chain component 1213 is:

[0130]

[0131] In this embodiment, the displacement of the three driving branch chain components 1213 is obtained by inverse analysis of the control module, and then the telescopic change of the driving hydraulic cylinder 12131 is solved, so as to control the driving branch chain components 1213 of the three-degree-of-freedom parallel stable platform 1 to drive the moving platform 13 to move, so as to achieve the purpose of adjusting the posture of the assembled valve body 31.

[0132] As an implementation method, Fig.10As shown, the upper support clamping device 15 in this embodiment includes a clamping base 151 fixedly mounted on the moving platform 13, an adjustable bracket 153 slidably arranged on the clamping base 151 through a vertical sliding module 152, a clamping hydraulic cylinder 154 mounted on the adjustable bracket 153, an upper clamping arm 156 rotatably connected to the telescopic end of the clamping hydraulic cylinder 154 through a swivel pin 155, an upper pressure plate 157 connected to the output end of the upper clamping arm 156, and a second proportional servo valve 158 mounted on the clamping hydraulic cylinder 154 for controlling the flow of the clamping hydraulic cylinder 154. The upper clamping arm 156 includes an active rod 1561 and a driven rod 1562 arranged in parallel on the adjustable bracket 153, and a small arm driving rod 1563 rotatably connected to the ends of the active rod 1561 and the driven rod 1562; the telescopic end of the clamping hydraulic cylinder 154 is rotatably connected to the active rod 1561 through a rotary pin shaft 155, and the upper pressure plate 157 is fixedly installed at the end of the small arm driving rod 1563.

[0133] The upper pressure plate 157 in this embodiment is an annular pressure plate, and the adjustable bracket 153 is installed on the clamping base 151 by bolts to ensure that the upper pressure plate 157 is completely in contact with the valve body and the mounting surface of the valve upper support 32. The clamping hydraulic cylinder 154 is installed on the adjustable bracket 153 by fastening bolts. The end of the hydraulic rod of the clamping hydraulic cylinder 154 is connected to the swivel pin 155. The extension and retraction of the hydraulic rod drives the rotation and deformation of the upper clamping arm 156, thereby driving the upper pressure plate 157 to move up and down, thereby realizing the clamping or disengagement action of the upper pressure plate 157 on the valve upper support 32.

[0134] See also Figures 7 to 9 The positioning and tightening device 14 includes two positioning and tightening mechanisms 141 symmetrically arranged on the moving platform 13, namely a left positioning and tightening mechanism 141 and a right positioning and tightening mechanism 141. The positioning and tightening mechanism 141 includes a side positioning base 1411 fixedly installed on the moving platform 13, a six-jaw chuck base 1413 slidably installed on the side positioning base 1411 through a horizontal moving module 1412, and a six-jaw chuck module 1414 installed on the six-jaw chuck base; the horizontal moving module 1412 on the left positioning and tightening mechanism 141 and the horizontal moving module 1412 on the right positioning and tightening mechanism 141 drive the six-jaw chuck module 1414 to fix and position the valve body 31 to be assembled.

[0135] The six-claw chuck module 1414 includes a six-claw chuck body mounted on a six-claw chuck base 1413, six claws 14142 arranged in a circumferential array on the six-claw chuck body, and a claw servo motor 14141 that drives the claws 14142 to close / tighten outward through a bevel gear set. The claw servo motor 14141 rotates the small bevel gear built into the six-claw chuck module 1414 clockwise, and the small bevel gear drives the large bevel gear to rotate counterclockwise, thereby driving the claws 14142 to open, and the claw servo motor 14141 rotates counterclockwise to drive the claws 14142 to close. The six claws 14142 use a bevel gear set and a servo motor to realize the opening and closing of the six claws 14142. The internal connection relationship thereof should be conceivable to those skilled in the art, and the specific connection implementation method will not be elaborated in detail here.

[0136] In this embodiment, the horizontal moving module includes a mounting plate arranged on the side positioning base 1411, a horizontal servo motor 14121 and a horizontal guide rail 14123 fixedly arranged on the mounting plate, a horizontal screw nut pair 14122 coaxially arranged with the output shaft of the horizontal servo motor 14121, and a horizontal slider 14124 fixedly connected to the nut seat of the horizontal screw nut pair 14122, and the horizontal slider 14124 is slidably matched with the horizontal guide rail 14123. It should be noted that the above structure of the horizontal moving module in this embodiment is only an implementation method for realizing the relative sliding of the six-claw chuck base 1413 and the moving platform 13, and other implementation methods that can be thought of by those skilled in the art can also be adopted, which does not limit the robot of the present invention. Furthermore, the vertical moving module 152 in this embodiment also adopts a screw nut pair transmission method, which will not be elaborated in detail here.

[0137] In order to realize the fully automated assembly of the robot, the robot also includes a data acquisition module and a control module for analysis and control. The data acquisition module includes a first force sensor 41 installed on the positioning and clamping device 14, a second force sensor 42 installed on the upper support and clamping device 15, and a visual sensor 43 installed on the upper support and clamping device 15; the first force sensor 41 is used to detect the opening force data of the six-claw chuck module 1414, and the control module receives the opening force data and compares it with the predetermined value to determine whether the valve body is in a tightened and fixed state on the moving platform 13; the second force sensor 42 is used to collect the pressure value of the upper support and clamping device 15 acting on the upper support of the valve body; the visual sensor 43 is used to collect image information in real time, and the control module receives the image information to determine whether the end of the manipulator 2 is aligned with the hole position of the valve body 31 to be assembled.

[0138] The first force sensor 41 is installed on the clamp, and is used to detect the acting force between the clamp and the valve body 31 to be assembled, and compare it with a predetermined value, so as to determine whether the valve body is in a tightened and fixed state on the moving platform 13, and provide a basis for whether the subsequent posture can be adjusted. The second force sensor 42 is installed on the forearm drive rod 1563 by bolts, and the upper pressure plate 157 is installed on the second force sensor 42 by bolts. The second force sensor 42 is used to detect the force applied to the upper support 32 of the valve. The visual sensor 43 bracket for installing the visual sensor 43 is installed on the forearm drive rod 1563 by bolts, and the visual sensor 43 is installed on the visual sensor 43 bracket by threaded fitting. During the process of aligning the holes of the valve body and the upper support 32 of the valve, the visual sensor 43 continuously feeds back the collected images to the control module until the control module determines that the holes are completely aligned.

[0139] The robot of this embodiment, during the assembly process of the valve body and the valve upper support 32, places the valve body on the moving platform 13 through the gantry crane, and then uses the joint action of the left positioning and tightening mechanism 141 and the right positioning and tightening mechanism 141 to position and tighten both sides of the valve body. Specifically, the six-jaw chuck module 1414 is moved to the inside of the valve body through the horizontal moving module 1412, and the six clamping jaws are opened until the stress value measured by the second force sensor 42 reaches a predetermined value. Then, the driving motor in the horizontal moving module 1412 is self-locked, and the valve body is fixed on the moving platform 13. The manipulator 2 clamps the valve upper support 32 and places it on the valve body. The valve body posture is adjusted by rotating the valve upper support 32 and the moving platform 13, and the visual sensor 43 is used for real-time monitoring to meet the requirements of the hole position, thereby solving the problem of assembly error caused by the displacement of the valve body and other positions during the posture adjustment and bolt assembly and tightening process.

[0140] When the valve body is aligned with the hole position of the valve upper support 32, the clamping hydraulic cylinder 154 of the upper support clamping device 15 is started to drive the upper pressure plate 157 to clamp the valve upper support 32 until the stress value measured by the second force sensor 42 reaches a predetermined value. The clamping hydraulic cylinder 154 is self-locking. At this time, the valve upper support 32 will not move relative to the valve body when the bolts are assembled and tightened, which solves the problem of assembly error caused by the displacement of the valve upper support 32 during the process.

[0141] like Figure 6 As shown, the movable platform in this embodiment is also provided with a support block for supporting the valve body 4 to be assembled. The setting of the support block ensures the placement stability of the valve block 4 to be assembled, and further ensures that the position of the valve body and the like is offset during the bolt assembly and tightening process to cause assembly errors.

[0142] As shown in FIG. 12 , the chassis of the manipulator 2 in this embodiment is fixed on the ground or other placement platform. The manipulator 2 in this embodiment includes a chassis 21 fixedly set on the ground or the placement platform, a shoulder mechanism 22 rotatably mounted on the chassis 21, a large arm mechanism 23 rotatably mounted with the shoulder mechanism 22 in turn, an elbow joint mechanism 24, a small arm mechanism 25, a wrist mechanism 26, an actuator conversion mechanism 28, and a manipulator tool module 27. The manipulator tool module 27 includes a pneumatic clamp 271 mounted on the actuator conversion mechanism 28 and an electric screwdriver 272 fixedly mounted on the actuator conversion mechanism 28 through a connecting seat. The manipulator 2 has six degrees of freedom. During the assembly process, it cooperates with the stable platform to complete the hole alignment action between the valve body and the upper support 32 of the valve. The end of the manipulator is equipped with an actuator conversion mechanism 28, which can complete the clamping, hole alignment, screw assembly and tightening of the upper support 32 of the valve.

[0143] It should be understood that the structures of the shoulder mechanism 22, the upper arm mechanism 23, the elbow joint mechanism 24, the lower arm mechanism 25, and the wrist mechanism 26 of the manipulator 2 in this embodiment and the connection methods of each part are relatively mature, and the structures available on the market can be applied to the manipulator 2. The specific structures of each part will not be elaborated in detail here. The actuator conversion mechanism 28 in this embodiment is connected to the wrist mechanism 26 through the internal bearing, and the linear guide rail module of the electric screwdriver 272 and the pneumatic clamp 271 is connected to the actuator conversion mechanism 28 through bolts, wherein, The pneumatic clamp 271 includes a linear guide module fixedly mounted on the actuator conversion mechanism 28 and a pneumatic clamp set on the linear guide module through a slider. The pneumatic clamp is connected to the linear guide module through a transition fit. The actuator conversion mechanism 28 drives a rotatable conversion actuator through a built-in motor. When it is necessary to clamp the workpiece, the actuator is converted to the pneumatic clamp 271. The movement of the slider in the linear guide module drives the pneumatic clamp to contract or expand, thereby clamping the workpiece. When it is necessary to assemble and tighten the screws, the actuator is converted to an electric screwdriver 272.

[0144] The actuator conversion mechanism 28 is designed, and an electric screwdriver 272 and a pneumatic clamp 271 are installed on the actuator conversion mechanism 28. After the pneumatic clamp places the upper support 32 of the valve on the valve body, the upper support 32 of the valve is pressed by the clamping device 15, and the small arm mechanism 25 of the manipulator 2 moves upward, the actuator conversion mechanism 28 rotates, and the actuator is converted to the electric screwdriver 272 to absorb the screws for assembly. The operations of clamping, hole alignment, placement, and screw assembly of the upper support 32 of the valve are completed by a manipulator 2, which saves a lot of working space and improves economy. It should be further explained that the electric screwdriver 272 in this embodiment is equipped with a torque sensor. When the measured value reaches the pre-tightening torque of the screw, it will not be further tightened, otherwise it will continue to tighten, which solves the problem of manually tightening the screws with a torque wrench while ensuring that the workpiece is not crushed to produce cracks and affect the overall strength of the valve 3.

[0145] like Fig.13 As shown, the method for using the above-mentioned posture-adjustable valve assembly robot includes the following steps:

[0146] A1. Lift the valve body 31 to be assembled onto the moving platform 13;

[0147] A2. Pre-fix the valve body 31 to be assembled; that is, start the horizontal moving module 1412 on the left positioning and tightening mechanism 141 and the right positioning and tightening mechanism 141 to drive the six-jaw chuck base 1413 to move toward the valve body 31 to be assembled, until the left positioning and tightening mechanism 141 and the right positioning and tightening mechanism 141 are both in contact with the valve body 31 to be assembled, and the horizontal moving module 1412 is self-locking;

[0148] A3. The valve body 31 to be assembled is tightened and fixed; that is, the six-jaw chuck module 1414 is started to drive the claw 14142 to open, and after the value measured by the first force sensor 41 reaches a predetermined value, the six-jaw chuck module 1414 is self-locked, and the valve body 31 to be assembled is in a tightened and fixed state on the moving platform 13;

[0149] A4. Adjust the hole positions of the valve body 31 to be assembled and the upper support 32 of the valve; that is, the manipulator 2 clamps the upper support 32 of the valve and moves it to just above the mounting surface of the valve body. The control module controls the three-degree-of-freedom parallel mechanism 12 to move the valve body 31 to be assembled to adjust the position of the valve body 31 to be assembled, by receiving the image information collected in real time by the visual sensor 43, until the hole positions of the valve body 31 to be assembled and the corresponding upper support 32 of the valve are aligned;

[0150] A5. Press and assemble the upper support 32 of the valve and the valve body 31 to be assembled; start the upper support pressing device 15 to press the upper support 32 of the valve and the valve body 31 to be assembled, rotate the manipulator 2, and use the electric screwdriver 272 to pre-tighten and tighten the screws of the upper support 32 of the valve and the valve body 31 to be assembled;

[0151] A6. Valve 3 exit and initialization operation.

[0152] Specifically, the valve 3 entering the station for assembly process: after the valve body 31 to be assembled is hoisted onto the moving platform 13, the horizontal servo motor 14121 in the horizontal linear modules on both sides of the valve body 31 to be assembled rotates clockwise, driving the ball screw to rotate clockwise, and the screw nut assembly drives the six-jaw chuck base 1413 to move toward the valve body 31 to be assembled, and then the servo motor of the horizontal linear module self-locks, and the claw servo motor 14141 rotates clockwise, and the small bevel gear built-in in the six-jaw chuck module 1414 rotates clockwise, and the small bevel gear drives the large bevel gear to rotate counterclockwise, thereby driving the claw 14142 to open. After the value measured by the first force sensor 41 reaches the predetermined value, the claw servo motor 14141 self-locks. At this time, the valve body 31 to be assembled is in a tightened and fixed state on the moving platform 13.

[0153] Then, the pneumatic clamp 271 on the manipulator 2 clamps the valve upper support 32 to just above the mounting surface of the valve body to be installed, and the hydraulic rod of the upper support clamping device 15 is extended and retracted, driving the upper pressure plate 157 and the visual sensor 43 to move to above the valve upper support 32, and the image collected by the visual sensor 43 is fed back to the control module. After the control module processes the image recognition, it controls the size of the inlet and outlet oil ports of the three first proportional servo valves 12132 in the three-degree-of-freedom parallel stable platform 1, and then controls the extension and retraction of the driving hydraulic rod in the driving branch chain assembly 1213, and at the same time controls the manipulator 2 to clamp the valve upper support 32 and keep it just above the mounting surface of the valve body 31 to be assembled, so that it can adjust the posture of the valve upper support 32 and the valve body 31 to be assembled and align the hole positions, wherein, during the hole position alignment process, the visual sensor 43 continuously feeds back the collected image to the controller until the controller determines that the hole positions are completely aligned. The hydraulic rod corresponding to the clamping hydraulic cylinder 154 is extended and retracted to drive the upper pressure plate 157 to clamp the valve upper support 32 until the force applied to the second force sensor 42 reaches a predetermined value. At this time, the valve upper support 32 is in a clamped and fixed state on the valve body 31 to be assembled, and the manipulator 2 returns to its initial position.

[0154] Finally, in order to prevent the screws from getting stuck when the subsequent screws are installed due to the one-time tightening, the screw assembly process is set to two steps: pre-tightening and tightening. The actuator converter on the manipulator 2 rotates to convert the actuator into an electric screwdriver 272. The electric screwdriver 272 has magnetism after being energized, and absorbs the screws for assembly and pre-tightening. When the value measured by the torque sensor installed on the electric screwdriver 272 reaches a predetermined value, the electric screwdriver 272 will no longer tighten further. After all the screws are pre-tightened, they are tightened one by one to make the torque reach the predetermined value, and finally the purpose of assembling the support 32 on the valve is achieved.

[0155] The exit and initialization operation of valve 3 specifically includes the following steps:

[0156] A601. Robot 2 rotates to the initial position;

[0157] A602. The upper support clamping device 15 is separated from the valve 3 and rotated back to the initial position;

[0158] A603. Control the three-degree-of-freedom parallel mechanism 12 to level the moving platform 13, start the horizontal moving module 1412 of the positioning and tightening device 14 to move away from the valve 3, so that the valve 3 is in a movable state;

[0159] A604. Move valve 3 to the designated location using lifting equipment.

[0160] Specifically, after the assembly of the support 32 on the above-mentioned valve is completed, the manipulator 2 returns to the initial state position, the hydraulic rod corresponding to the clamping hydraulic cylinder 154 is extended and retracted to drive the upper pressure plate 157 to move upward, and the claw servo motor 14141 in the positioning and tightening device 14 on both sides of the assembled valve body rotates counterclockwise to drive the six claws 14142 to close, and the horizontal servo motor 14121 in the horizontal linear module rotates counterclockwise, and the horizontal servo motor 14121 drives the ball screw to rotate counterclockwise. According to the screw principle, when the screw rotates counterclockwise, the screw nut assembly moves away from the valve 3, thereby driving the six-claw chuck module 1414 to move to the initial state. At this time, the valve 3 is in a movable state, and it is moved to the designated location by the gantry crane.

[0161] As attached Figure 11-12 As shown, the specific process of assembling a valve 3 by a valve assembly robot with adjustable posture of the present invention is as follows:

[0162] The manual input command, if the control module determines that it is an entry command, the control module in this embodiment adopts a PID controller, wherein the horizontal servo motor 14121 that reaches the specified position needs to rotate at an angle determined according to the specific situation, the contactor corresponding to the horizontal servo motor 14121 is closed, the contactor corresponding to the claw servo motor 14141 in the six-claw chuck module 1414 is disconnected, the horizontal servo motor 14121 receives the electrical signal and rotates clockwise, during the rotation of the horizontal servo motor 14121, the corresponding encoder detects the rotation angle in real time and feeds back to the controller, when the controller receives the signal of reaching the specified position, the horizontal servo motor 14121 stops rotating, that is, the contactor corresponding to the horizontal servo motor 14121 is controlled to be disconnected, the contactor corresponding to the claw servo motor 14141 is closed, the claw servo motor 14141 receives the electrical signal and rotates clockwise, during the rotation of the claw servo motor 14141, the first pressure sensor detects the magnitude of the force in real time and feeds back to the controller, when the controller receives the signal that the force reaches the preset pressure value, the claw servo motor 14141 stops rotating, and the valve body tightening and fixing action is completed.

[0163] The controller sends a clamping electrical signal to the manipulator 2. After receiving the signal, the manipulator 2 clamps the valve upper support 3242 and adjusts the position of the upper support. During the adjustment process, the visual sensor 43 continuously feeds back the collected image to the controller until the valve upper support 32 is located above the mounting surface of the valve body 31 to be assembled. The controller sends a placement electrical signal to the manipulator 2. The manipulator 2 places the valve upper support 32 on the mounting surface and maintains the clamping action. The placement action of the valve upper support 32 is completed. When the visual sensor 43 collects the image of the valve upper support 32 being placed and sends it to the controller, the controller An electrical signal is sent to the first proportional servo valve 12132 in the three-degree-of-freedom parallel stable platform 1. After receiving the electrical signal, the first proportional servo valve 12132 controls the size of the oil inlet and outlet, thereby controlling the extension and retraction of the hydraulic rod in the driving hydraulic cylinder 12131, and then driving the moving platform 13 to move, so as to achieve the purpose of adjusting the posture of the valve body 31 to be assembled. During the posture adjustment process, the visual sensor 43 continuously feeds back the collected image to the controller to fully align the hole position, and the first proportional servo valve 12132 controls the oil port to stop the oil inlet and outlet, and the alignment action of the valve upper support 32 and the hole position of the valve body 31 to be assembled is completed.

[0164] The controller sends an electrical signal to the second proportional servo valve 158 in the clamping device 15 of the upper support 32 of the valve. After receiving the electrical signal, the second proportional servo valve 158 controls the size of the inlet and outlet oil ports, thereby controlling the extension and retraction of the hydraulic rod corresponding to the clamping hydraulic cylinder 154, and then driving the upper pressure plate 157 to move, thereby achieving the purpose of clamping the upper support 32 of the valve. During the downward pressure of the upper pressure plate 157, the second force sensor 42 detects the size of the force in real time and feeds back to the controller. When the controller receives a signal that the force reaches a preset pressure value, the second proportional servo valve 158 controls the oil port to stop the inlet and outlet of oil, and the manipulator 2 returns to the initial state, and the clamping action of the upper support 32 of the valve is completed.

[0165] The controller sends an electrical signal for screw assembly to the manipulator 2. After receiving the electrical signal, the manipulator 2 controls the actuator conversion mechanism 28 to rotate and converts the actuator into an electric screwdriver 272. The electric screwdriver 272 absorbs the screws for assembly and pre-tightening. When the value measured by the torque sensor of the electric screwdriver 272 reaches a predetermined value, the controller sends an electrical signal to the manipulator 2, and the electric screwdriver 272 no longer tightens the screws further. After all the screws are pre-tightened, they are tightened one by one until the torque reaches the predetermined value. The manipulator 2 returns to the initial state, and the assembly action of the screws on the support 32 of the valve is completed.

[0166] An exit instruction is sent to the controller, and the controller sends an electrical signal to the second proportional servo valve 158 in the clamping device 15 of the upper support 32 of the valve. After receiving the electrical signal, the second proportional servo valve 158 controls the size of the inlet and outlet oil ports, thereby controlling the extension and retraction of the hydraulic rod corresponding to the clamping hydraulic cylinder 154, and then driving the upper pressure plate 157 to move, so as to achieve the purpose of releasing the clamping of the upper support 32 of the valve. During the rising process of the upper pressure plate 157, the visual sensor 43 collects images in real time and feeds back to the controller. When the controller receives a signal that the specified position has been reached, the second proportional servo valve 158 stops the oil inlet and outlet, and the initialization action of the clamping device 15 of the upper support 32 of the valve is completed.

[0167] The contactor corresponding to the claw servo motor 14141 is closed, and the claw servo motor 14141 rotates counterclockwise after receiving the electrical signal. During the rotation of the claw servo motor 14141, the corresponding encoder detects the rotation angle in real time and feeds back to the controller. When the controller receives the signal that the designated position has been reached, the claw servo motor 14141 stops rotating, the contactor corresponding to the claw servo motor 14141 is disconnected, and the initialization action of the claw 14142 is completed. The horizontal moving module 1412 drives the six-claw chuck base 1413 to move. When the controller receives the signal that the six-claw chuck base 1413 has reached the designated position, the horizontal servo motor 14121 stops rotating, the contactor corresponding to the horizontal servo motor 14121 is disconnected, and the initialization action of the valve body positioning and tightening device 14 is completed. The purpose of opening / closing the two contactors corresponding to the horizontal servo motor 14121 and the claw servo motor 14141 is to interlock the two motors to prevent the two contactors from being attracted at the same time, thereby causing misoperation and power short circuit. In order to deal with emergencies such as power outages during the assembly process, an outbound instruction can be directly sent to the controller to interrupt the assembly process. The principle and process are the same as the outbound after assembly and will not be repeated here.

[0168] It should be understood that the specific embodiments described above are only used to explain the present invention, and are not used to limit the present invention. Obvious changes or modifications derived from the spirit of the present invention are still within the protection scope of the present invention.

Claims

1. A valve assembly robot with adjustable posture, characterized in that: The invention comprises a three-degree-of-freedom parallel stable platform (1) for placing a valve body (31) to be assembled and a manipulator (2) for clamping and installing a valve upper support (32); the three-degree-of-freedom parallel stable platform (1) comprises a base plate (11), a three-degree-of-freedom parallel mechanism (12) mounted on the base plate (11), a movable platform (13) rotatably connected to the output end of the three-degree-of-freedom parallel mechanism (12), a positioning and clamping device (14) and an upper support clamping device (15) mounted on the movable platform (13) for positioning and clamping the valve body (31) to be assembled; The three-degree-of-freedom parallel mechanism (12) comprises three posture adjustment components of the same structure, namely a first posture adjustment component (121), a second posture adjustment component (122) and a third posture adjustment component (123); the first posture adjustment component (121) and the second posture adjustment component (122) are symmetrically arranged, and both are perpendicular to the third posture adjustment component (123) on a horizontal plane; The posture adjustment component comprises a base (1211) fixedly mounted on the base plate (11), a fixed-length constraint chain component (1212) mounted on the base plate (1211), and a drive branch chain component (1213); one end of the fixed-length constraint chain component (1212) is rotatably connected to the base plate (1211), and the other end is rotatably connected to the moving platform (13); the drive branch chain component (1213) changes the distance of the moving platform (13) relative to the base plate (11) in the vertical direction; the fixed end of the drive branch chain component (1213) is rotatably connected to the base plate (11), and the telescopic end thereof is rotatably connected to the moving platform (13); The position and posture of the valve body (31) to be assembled, which is arranged on the moving platform (13), are adjusted by the displacement change of the three driving branch chain components (1213) and the constraints of the three fixed-length constraint chain components (1212); in the initial state, the fixed ends of the three driving branch chain components (1213) are arranged to form a triangular structure, and the extension and retraction directions of the three driving branch chain components (1213) are perpendicular to the bottom plate (11); and the plane formed by the three fixed-length constraint chain components (1212) in space is on a horizontal plane.

2. The valve assembly robot with adjustable posture according to claim 1, characterized in that: The movable platform (13) has a triangular structure, and the fixed-length restraint chain assembly (1212) comprises a fixed-length restraint rod (12121) having one end rotatably connected to the base (1211) via a joint bearing (12122) and the other end rotatably mounted to the vertex of the movable platform (13) via a joint bearing (12122).

3. The position-adjustable valve assembly robot according to claim 2, characterized in that: The drive branch chain assembly (1213) comprises: A driving hydraulic cylinder (12131), the fixed end of which is rotatably mounted on the base (1211) via a lower support assembly, and the telescopic end of the driving hydraulic cylinder (12131) is rotatably mounted on the vertex of the moving platform (13) via an upper support assembly; A first proportional servo valve (12132) is installed on the driving hydraulic cylinder (12131) and is used to adjust the flow of the driving hydraulic cylinder (12131).

4. The valve assembly robot with adjustable posture according to claim 3, characterized in that: The driving displacement calculation of the three driving branch chain components (1213) specifically includes: With the center of the moving platform (13) as the origin O, the moving platform (13) motion coordinate system (X P , Y P , Z P ); Take the center of the bottom plate (11) as the origin O1, and set the platform coordinate system (X L , Y L , Z L ); The fixed platform coordinate system is parallel to the Cartesian coordinate system (x, y, z); The kinematic analysis of the three-degree-of-freedom parallel stabilized platform (1) is performed to obtain the kinematic spiral system. S for: ； Where P z represents the movement of the moving platform (13) along the z-axis, R x represents the rotation of the moving platform (13) around the x-axis, R y represents the rotation of the moving platform (13) around the y-axis; According to the above-mentioned motion spiral system, the three-degree-of-freedom parallel mechanism (12) includes a vertical swing movement degree of freedom, a roll rotation degree of freedom and a pitch rotation degree of freedom, and the vertical swing movement degree of freedom is the movement along the z-axis. z The roll and pitch degrees of freedom are the rotation of the moving platform (13) around the x and y axes respectively. θ x = γ , θ y = β ; Establish the constraint equation according to the position of the fixed-length constraint rod (12121): ； In the formula, l m Indicates the length of the fixed-length restraint rod (12121), F i (i=1,2,3),D i (i=1,2,3) are respectively the center points of the fixed-length constraint rod (12121) and the movable platform (13) and the fixed platform (1) connecting the joint bearing (12122), and their positions in the fixed platform coordinate system are (F ix , F iy , F iz )、(D ix , D iy , D iz ); The displacement of the three driving branch chain components (1213) is solved by using the inverse kinematics of the parallel mechanism combined with the above constraint equations: According to the known position and posture of the moving platform (13), the three input lengths of the drive branch chain components (l1, l2, l3) are solved: ； In the formula, R a R represents the radius of the circumscribed circle of the hinge point of the moving platform. b represents the radius of the circumscribed circle of the fixed platform hinge point, H is the initial vertical distance between the moving platform and the fixed platform, r ij Represents the moving coordinate system (X P , Y P , Z P ) relative to the fixed coordinate system (X L , Y L , Z L )The corresponding value of the i-th row and j-th column in the rotation transformation matrix, η i represents the angle between each hinge point and the x-axis, where i=1,2,3; The telescopic displacement of the hydraulic rod corresponding to the driving hydraulic cylinder is obtained by subtracting the initial length of the driving branch chain assembly from the length of the driving branch chain assembly solved above.

5. The valve assembly robot with adjustable posture according to claim 1, characterized in that: The upper support clamping device (15) comprises a clamping base (151) fixedly mounted on the movable platform (13), an adjustable bracket (153) slidably arranged on the clamping base (151) via a vertical sliding module (152), a clamping hydraulic cylinder (154) mounted on the adjustable bracket (153), an upper clamping arm (156) rotatably connected to the telescopic end of the clamping hydraulic cylinder (154) via a swivel pin (155), an upper pressure plate (157) connected to the output end of the upper clamping arm (156), and a second proportional servo valve (158) mounted on the clamping hydraulic cylinder (154) for controlling the flow of the clamping hydraulic cylinder (154); The upper clamping arm (156) comprises an active rod (1561) and a driven rod (1562) which are arranged in parallel on the adjustable bracket (153), and a small arm driving rod (1563) which is rotatably connected to the ends of the active rod (1561) and the driven rod (1562); the telescopic end of the clamping hydraulic cylinder (154) is rotatably connected to the active rod (1561) via a swivel pin (155), and the upper pressure plate (157) is fixedly mounted on the end of the small arm driving rod (1563).

6. The position-adjustable valve assembly robot according to claim 1, characterized in that: The positioning and tightening device (14) comprises two positioning and tightening mechanisms (141) symmetrically arranged on the moving platform (13), namely a left positioning and tightening mechanism (141) and a right positioning and tightening mechanism (141); The positioning and clamping mechanism (141) comprises a side positioning base (1411) fixedly mounted on the moving platform (13), a six-jaw chuck base (1413) slidably mounted on the side positioning base (1411) via a horizontal moving module (1412), and a six-jaw chuck module (1414) mounted on the six-jaw chuck base (1413); the horizontal moving module (1412) on the left positioning and clamping mechanism (141) and the horizontal moving module (1412) on the right positioning and clamping mechanism (141) drive the six-jaw chuck module (1414) to fix and position the valve body (31) to be assembled.

7. The position-adjustable valve assembly robot according to claim 6, characterized in that: The manipulator (2) comprises a chassis (21) fixedly arranged on the ground or a placement platform, a shoulder mechanism (22) rotatably mounted on the chassis (21), an arm mechanism (23) rotatably mounted on the shoulder mechanism (22), an elbow joint mechanism (24), a forearm mechanism (25), a wrist mechanism (26), an actuator conversion mechanism (28), and a manipulator tool module (27); The manipulator tool module (27) comprises a pneumatic clamp (271) mounted on the actuator conversion mechanism (28) and an electric screwdriver (272) fixedly mounted on the actuator conversion mechanism (28) via a connecting seat.

8. The position-adjustable valve assembly robot according to claim 7, characterized in that: It also includes a data acquisition module (4) and a control module for analysis and control; The data acquisition module (4) comprises a first force sensor (41) installed on the positioning and clamping device (14), a second force sensor (42) installed on the upper support and clamping device (15), and a visual sensor (43) installed on the upper support and clamping device (15); the first force sensor (41) is used to detect the opening force data of the six-jaw chuck module (1414), the control module receives the opening force data, compares it with a predetermined value, and determines whether the valve body is in a clamped and fixed state on the moving platform (13); the second force sensor (42) is used to collect the pressure value of the upper support and clamping device (15) acting on the upper support of the valve body; the visual sensor (43) is used to collect image information in real time, the control module receives the image information, and determines whether the end of the manipulator (2) is aligned with the hole position of the valve body (31) to be assembled.

9. The method for using a posture-adjustable valve assembly robot according to claim 8, characterized in that: The following steps are involved: A1. Lift the valve body (31) to be assembled onto the moving platform (13); A2. Pre-fixing the valve body (31) to be assembled; that is, starting the horizontal moving module (1412) on the left positioning and tightening mechanism (141) and the right positioning and tightening mechanism (141), driving the six-jaw chuck base (1413) to move toward the valve body (31) to be assembled, until the left positioning and tightening mechanism (141) and the right positioning and tightening mechanism (141) are both in contact with the valve body (31) to be assembled, and the horizontal moving module (1412) is self-locking; A3. The valve body (31) to be assembled is tightened and fixed; that is, the six-jaw chuck module (1414) is started to drive the chuck jaws (14142) to be opened, and after the value measured by the first force sensor (41) reaches a predetermined value, the six-jaw chuck module (1414) is self-locked, and the valve body (31) to be assembled is in a tightened and fixed state on the moving platform (13); A4. Adjusting the hole positions of the valve body (31) to be assembled and the valve upper support (32); that is, the manipulator (2) grasps the valve upper support (32) and moves it to the position just above the valve body installation surface, and the control module controls the three-degree-of-freedom parallel mechanism (12) to move the valve body (31) to be assembled to adjust the position of the valve body (31) to be assembled by receiving image information collected in real time by the visual sensor (43), until the hole positions of the valve body (31) to be assembled and the corresponding valve upper support (32) are aligned; A5. Press and assemble the upper support (32) of the valve and the valve body (31) to be assembled; start the upper support pressing device (15) to press the upper support (32) of the valve and the valve body (31) to be assembled, rotate the manipulator (2), and use the electric screwdriver (272) to pre-tighten and tighten the screws of the upper support (32) of the valve and the valve body (31) to be assembled; A6. Valve (3) exit and initialization operation.

10. The method for using a posture-adjustable valve assembly robot according to claim 9, characterized in that: The valve (3) exit and initialization operation specifically includes the following steps: A601. The manipulator (2) rotates to its initial position; A602. The upper support clamping device (15) is separated from the valve (3) and rotated back to the initial position; A603. Control the three-degree-of-freedom parallel mechanism (12) to level the moving platform (13), start the horizontal moving module (1412) of the positioning and tightening device (14) to move away from the valve (3), so that the valve (3) is in a movable state; A604. Move the valve (3) to the designated location using lifting equipment.

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