Multi-degree-of-freedom pose adjustment method for target with large length-diameter ratio

Abstract

The invention discloses a multi-degree-of-freedom pose adjustment method for a large-length-diameter-ratio target, and belongs to the technical field of multi-degree-of-freedom pose adjustment of automatic spraying equipment.The multi-degree-of-freedom pose adjustment method comprises the steps that firstly, the tail end pose deviation value of the target is obtained; and establishing a five-connecting-rod model and a forward kinematics model of the pose adjusting device. A five-connecting-rod model is constructed along the tail end of the large-length-diameter-ratio target, the pitching unit, the rotation unit, the transverse moving unit and the supporting foot unit in sequence; constructing a forward kinematics transformation matrix based on a product of coordinate transformation of the five connecting rods; and based on the forward kinematics transformation matrix, inversely solving the adjustment amount of each motion axis of the pose adjustment device at the target tail end pose deviation amount. And finally, according to an inverse solution result, adjusting each motion axis of the pose adjusting device so as to realize multi-degree-of-freedom pose adjustment of the tail end of the target with the large length-diameter ratio. According to the method, high-precision adjustment of the tail end posture is achieved, the purpose of precise adjustment of the automatic spraying length-diameter ratio target posture is achieved, and good practicability is achieved.

Description

Technical Field

[0001] This invention belongs to the technical field of multi-degree-of-freedom pose adjustment of automated spraying equipment, specifically relating to a multi-degree-of-freedom pose adjustment method for a target with a large aspect ratio. Background Technology

[0002] Currently, the automation level of aviation painting equipment is limited, especially for painting large aspect ratio aviation targets. For example, Chinese patent CN111300081A discloses an attitude adjustment device and method for achieving multi-degree-of-freedom motion, utilizing a screw elevator, a cross slide, a tension spring, and a ball joint structure to achieve six degrees of freedom motion of components. The X / Y translational motion and minor adjustments in the A / B / C directions of the aircraft components can be manually and quickly adjusted; the Z-axis vertical motion and A-axis rotational motion of the aircraft components rely on the quantitative adjustment of the screw elevator to achieve real-time quantitative control, realizing six degrees of freedom motion. However, the presence of gaps in the ball joint fit in this scheme reduces the platform's attitude adjustment repeatability and rigidity, making it difficult to meet the requirements for precise angle adjustment of large aspect ratio targets; at the same time, the parallel drive of the platform through four screw elevators connected by ball joints for attitude adjustment requires high algorithm accuracy and synchronous control accuracy, which can easily lead to mechanism motion jamming and affect operational stability. Summary of the Invention

[0003] The purpose of this invention is to provide a multi-degree-of-freedom pose adjustment method for a target with a large aspect ratio, aiming to solve any of the above-mentioned problems and achieve precise pose adjustment of the target with a large aspect ratio.

[0004] This invention is mainly achieved through the following technical solutions: A method for adjusting the pose of a target with a large aspect ratio using multiple degrees of freedom includes the following steps: Step S1: Obtain the target end attitude deviation ( , , , ); in: This is the horizontal displacement adjustment amount; This refers to the vertical adjustment amount. This is the horizontal plane rotation adjustment amount; This is the vertical plane pitch adjustment amount; Step S2: Establish the five-bar model and forward kinematics model of the pose adjustment device; The posture adjustment device includes a main body and support units located on the periphery of the bottom of the main body. The support units are used to adjust the pitch angle, yaw angle, and vertical height of the main body. The main body includes a pitch unit, a rotation unit, and a traverse unit arranged sequentially from top to bottom. Support units are arranged on the periphery of the traverse unit. The pitch unit is used to drive the workbench to perform a swaying motion. The rotation unit is used to drive the pitch unit to perform a circumferential rotation motion. The traverse unit is used for the linear motion of the rotation unit. Step S21: Construct a five-link model sequentially along the end of the target with a large aspect ratio and the pitch, rotation, lateral and support units; Step S22: Establish the representation matrix for each link; Step S23: Construct the forward kinematic transformation matrix based on the product of the coordinate transformations of the five links; Step S3: Based on the forward kinematics transformation matrix, inversely solve the attitude deviation of each motion axis of the pose adjustment device at the target end ( , , , Adjustment amount at time; Step S4: Based on the inverse kinematics result in step S3, adjust each motion axis of the pose adjustment device to achieve a multi-degree-of-freedom pose adjustment of the target end with a large aspect ratio.

[0005] Specifically, the representation matrix of each link refers to the homogeneous transformation matrix used in robotics or mechanics to describe the relative position and orientation between adjacent links, also known as the link transformation matrix or A matrix.

[0006] To better realize the present invention, further, in step S2, the pitch unit, rotation unit, traverse unit, and support unit are respectively provided with a worktable, a rotation table, a traverse table, and a base frame arranged sequentially from top to bottom; the pitch unit is used to drive the worktable to swing around the bearing support axis on the rotation table; the rotation unit is used to drive the rotation table to rotate around the support bearing axis on the traverse table; the traverse unit is used to drive the traverse table to move linearly relative to the base frame; the support unit is used to adjust the pitch angle, sway angle, and vertical height position of the base frame.

[0007] To better implement the present invention, step S21 further includes the following steps: (1) Establish an initial link coordinate system at the bottom of the support element; Establish the first link coordinate system at the intersection of the support element and the transverse element; Establish a second link coordinate system along the centerline of the transverse unit; A third link coordinate system is constructed at the intersection of the central axis of the pitch arc of the rotary table motion and the central axis of the rotation arc; Construct a fourth link coordinate system at the intersection of the central axis of the pitch arc of the workbench movement and the central axis of the rotation arc; Construct a fifth link coordinate system at the end center point of the target with a large aspect ratio; (2) The initial link coordinate system and the first link coordinate system, the first link coordinate system and the second link coordinate system, the second link coordinate system and the third link coordinate system, the third link coordinate system and the fourth link coordinate system, and the fourth link coordinate system and the fifth link coordinate system are respectively provided with a first link, a second link, a third link, a fourth link, and a fifth link.

[0008] To better realize the present invention, further, in step S22, an expression matrix for the first to fifth links is established: ; ; ; ; ; in: L 1 is the length of the third link, and it is equal to the distance from the transverse axis to the axis of rotation. It is the joint angle of the third link, and is equal to the rotation angle of the posture adjustment device; It is the joint angle of the fourth link, and is equal to the pitch angle of the posture adjustment device; d 1 is the offset of the first link, which is equal to the ground clearance of the lateral movement unit and has an initial value. After adjusting the support unit, d1 will change accordingly. ,in: It is the amount of movement of the support; d 2 is the offset of the second link, and the center line of the transverse translation element is equal to that of the first coordinate system. The distance between the axes, with an initial value. After the transverse unit moves, d2 will change accordingly. ,in: It is the amount of motion of the lateral movement unit; d 3 is the offset of the third link, and it is equal to the distance from the third link to the origin of the coordinate system of the third link; d4 is the offset of the fifth link, and it is equal to the distance from the origin of the coordinate system of the fourth link to the target with the large aspect ratio; L 2 is the length of the fifth link, and it is equal to the length of the target with the large length-to-diameter ratio.

[0009] To better realize the present invention, further, in step S23, the positive kinematic transformation matrix is: ; in: ; ; ; ; ; ; ; ; ; ; ; .

[0010] To better implement the present invention, further, in step S3, the adjustment amount is obtained ( , , , This includes the following steps: Step S31: Assume ,and Each element in the table represents the target value; in: nx , ny , nz They are respectively , , ; ox , oy , oz They are respectively , , ; , , They are respectively , , ; qx , qy , qz They are respectively , , These can respectively characterize the origin of the fifth link coordinate system in the initial link coordinate system. axis, axis, Axis coordinates; Step S32: Based on step S31, solve the simultaneous equations. Solving for: ; Step S33: Based on step S31, solve the simultaneous equations. Solving for: ; Step S34: Based on step S31, solve the simultaneous equations. Solving for: ; Step S35: Based on step S31, solve the simultaneous equations. Solving for: ; in: This represents the amount of motion of the support frame, and the amount of attitude deviation of the posture adjustment device at the end. , , , The actual adjustment amount of vertical plane lifting during the process.

[0011] The motion of the lateral movement unit is the attitude deviation of the pose adjustment device at the end point. , , , The actual adjustment amount of horizontal plane lateral movement at that time.

[0012] The beneficial effects of this invention are as follows: This invention establishes a forward kinematic model of the pose adjustment device and performs inverse kinematics calculations on the adjustment amounts of each motion axis. It calculates the adjustment amounts of each motion axis when the pose deviation of the target end is known, and ultimately achieves high-precision adjustment of the end pose. This solves the problem of precise pose adjustment of the target with a length-to-diameter ratio in automatic spraying and has good practicality. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the posture adjustment device. Figure 2 This is a schematic diagram of the swing mechanism; Figure 3 This is a schematic diagram of the rotary unit. Figure 4 This is a bottom view of the posture adjustment device; Figure 5This is the front view of the pose adjustment device; Figure 6 This is a schematic diagram of a five-bar linkage model; Figure 7 This is a flowchart of the multi-degree-of-freedom attitude adjustment method for a target with a large aspect ratio according to the present invention.

[0014] Wherein: 311-Workbench frame, 3111-Linear guide rail slider pair I, 312-Swing mechanism, 3121-Slide table, 3122-Hinge, 3123-Swing table, 313-Screw screw and nut pair I, 314-Bearing support, 315-Rotary table frame, 3151-Linear guide rail slider pair II, 316-Angle measuring sensor I, 317-Drive device II, 3171-Servo motor II, 3172-Reducer II. 321-Gear and rack pair II, 322-Arc-shaped guide rail pair, 323-Support bearing, 324-Transverse moving platform, 325-Angle measuring sensor II, 326-Drive device III, 3261-Servo motor III, 3262-Reducer III 331-Base frame, 332-Lead screw and nut pair II, 3321-Nut II, 3322-Lead screw II, 3323-Bearing housing, 333-Linear guide rail and slider pair III, 335-Drive device IV, 3351-Servo motor IV, 3352-Reducer IV 34-Feet unit, 341-Fixed body, 342-Moving body, 343-Foot plate 100 - Initial link coordinate system, 101 - First link coordinate system, 102 - Second link coordinate system, 103 - Third link coordinate system, 104 - Fourth link coordinate system, 105 - Fifth link coordinate system 200 - First link offset, 201 - Second link offset, 202 - Third link length, 203 - Third link offset, 204 - Third link joint angle, 205 - Fourth link joint angle, 206 - Fifth link offset, 207 - Fifth link length. Detailed Implementation

[0015] Example 1: A multi-degree-of-freedom pose adjustment method for targets with high aspect ratios calculates the adjustment amounts of each motion axis of the pose adjustment device based on the target's end-effector pose deviation, thereby achieving accurate pose adjustment of the target. Figure 7 As shown, the specific steps include: S1: Known target end attitude deviation ( , , , ); in: This is the horizontal displacement adjustment amount; This refers to the vertical adjustment amount. This is the horizontal plane rotation adjustment amount; This is the vertical plane pitch adjustment amount; S2: Establish the five-bar linkage model and forward kinematics model of the posture adjustment device; S21: As Figure 6 As shown, a five-bar model of the pose adjustment device is established.

[0016] like Figures 1-5 As shown, the posture adjustment device includes a pitch unit, a rotation unit, a lateral movement unit and a support unit 34 arranged sequentially from top to bottom; the lateral movement unit is provided with a support unit 34 on its periphery.

[0017] The pitch unit, rotation unit, traverse unit, and support unit 34 are respectively provided with a workbench, a rotary table, a traverse table, and a base frame arranged sequentially from top to bottom. The pitch unit is used to drive the workbench 311 to swing around the axis of the bearing support 314 on the rotary table 315. The rotation unit is used to drive the rotary table 315 to rotate around the axis of the support bearing 323 on the traverse table 324. The traverse unit is used to drive the traverse table 324 to move linearly relative to the base frame 331. The support unit 34 is used to adjust the pitch angle, sway angle, and vertical height position of the base frame 331.

[0018] like Figure 6 As shown, a five-link model is established. The initial link coordinate system 100 is located at the bottom of the support unit 34; the link offset d1 is a variable parameter with an initial height value d1_0; the first link coordinate system 101 is located at the intersection of the support unit 34 and the lateral unit; the link offset d2 is a variable parameter with an initial value of the horizontal distance d2_0 from the center line of the lateral unit to the support unit 34; the second link coordinate system 102 is located at the center line of the lateral unit; the third link coordinate system 103 and the fourth link coordinate system 104 are located at the intersection of the central axis of the pitch arc and the central axis of the rotation arc; the fifth link coordinate system 105 is located at the end center point of the target with a large aspect ratio.

[0019] As shown in Table 1, where: L1 is the length of the third link, 202, and is equal to the distance from the transverse axis to the axis of rotation; d 1 is the offset of the first link, which is 200, and equal to the ground clearance of the lateral movement unit; d 2 is the offset of the second link, 201, and is equal to the distance from the center line of the transverse translation element to the first coordinate system. Distance between axes; L1 is the length of the third link, 202, and equal to the line d2 extending to the coordinate system of the third link, 103. Distance along the axial direction; d3 is the offset of the third link 203, and is equal to the distance in the height direction from the line L1 to the origin of the coordinate system 103 of the third link; d4 is the offset of the fifth link, 206, and is equal to the distance from the origin of the fourth link's coordinate system 104 to the target with a large aspect ratio. It is the joint angle of the third link, 204, and is equal to the rotation angle of the posture adjustment device; It is the fourth link joint angle of 205°, which is equal to the pitch angle of the posture adjustment device; L2 is the length of the fifth link, 207, which is equal to the length of the target with a large aspect ratio.

[0020] S22: Based on the link parameters and The general expression is used to establish the expression matrix for each link, and the results are as follows: ; , , , , ; S23: Construct the forward kinematic transformation matrix based on the product of the coordinate transformations of the five links: ; in: ; ; ; ; ; ; ; ; ; ; ; .

[0021] S3: Inverse solution of the attitude deviation of each motion axis at the target end ( , , , Adjustment amount when () , , , ).

[0022] in: This represents the amount of motion of the support frame, and the amount of attitude deviation of the posture adjustment device at the end. , , , The actual adjustment amount of vertical plane lifting and lowering during the process.

[0023] The motion of the lateral movement unit is the attitude deviation of the pose adjustment device at the end point. , , , The actual adjustment amount of horizontal displacement during the process.

[0024] It is the joint angle of the third link, 204, and is equal to the rotation angle of the posture adjustment device; It is the fourth link joint angle of 205°, which is equal to the pitch angle of the posture adjustment device; S31: Make an assumption, let... and Each element in the table represents the target value; S32: Simultaneous Equations Solving for: ; S33: Simultaneous Equations Solving for: ; S34: Simultaneous Equations Solving for: .

[0025] S35: Simultaneous Equations Solving for: .

[0026] S4: Based on the inverse kinematics result, adjust each motion axis of the pose adjustment device to achieve a multi-degree-of-freedom pose adjustment of the target end with a large aspect ratio.

[0027] Table 1 Linkage Parameters

[0028] Example 2: This embodiment is an optimization based on Embodiment 1, such as... Figures 1-5 As shown, the specific structure of the pose adjustment device is as follows: The pitch unit includes a workbench 311, a swing mechanism 312, a lead screw and nut assembly I 313, a bearing support 314, a rotary table 315, an angle measuring sensor I 316, and a drive device II 317. A target 2 with a large length-to-diameter ratio is mounted on the upper part of the workbench 311. A linear guide rail slider assembly I 3111 is mounted on one inclined surface of the lower part of the workbench 311, and the other end is connected to the bearing support 314. The workbench 311 can swing around the bearing axis of the bearing support 314, and the bearing support 314 is fixedly connected to the rotary table 315. The swing mechanism 312 includes a slide 3121, a hinge 3122, and a swing platform 3123. The swing platform 3123 is connected to the slide 3121 through the hinge 3122, and the swing platform 3123 can swing around the axis connected to the hinge 3122.

[0029] The slide 3121 of the swing mechanism 312 is connected to the rotary table 315 via linear guide slider pair II 3151 and lead screw and nut pair I 313. The swing table 3123 of the swing mechanism 312 is connected to the workbench 311 via linear guide slider pair I 3111. The drive device II 317 is connected to the lead screw and nut pair I 313. The drive device II 317 consists of a servo motor II 3171 and a reducer II 3172. It drives the swing mechanism 312 to move linearly along the axis of the linear guide slider pair II 3151 via the lead screw and nut pair I 313. During the linear motion of the swing mechanism 312 along the axis of the linear guide slider pair II 3151, the linear motion of the slide 3121 is converted into the swing motion of the workbench 311 around the axis of the bearing support 314. The angle measuring sensor I is coaxially connected to the rotation axis of the bearing support 314 and can detect the angle value of the rotation of the workbench 311 around the axis of the bearing support 314.

[0030] like Figure 3 and Figure 5 As shown, the rotary unit includes a rack and pinion pair II 321, an arc-shaped guide rail pair 322, a support bearing 323, a transverse platform 324, an angle measuring sensor II 325, and a drive device III 326. The rotary platform 315 is connected to the transverse platform 324 via the arc-shaped guide rail pair 322 and the support bearing 323. The rack and pinion pair II 321 consists of an arc-shaped rack and a gear II. The central axis of the arc of the arc-shaped rack and the arc-shaped guide rail pair 322 is coaxial with the axis of the support bearing 323. The drive device III 326 consists of a servo motor III 3261 and a reducer III 3262, which drives the rotary platform 315 to rotate around the axis of the support bearing 323 via the rack and pinion pair II 321. The angle measuring sensor II 325 is connected to the support bearing 323 and can detect the angle value of the rotary platform 315 rotating around the axis of the support bearing 323.

[0031] like Figure 4 and Figure 5As shown, the transverse unit includes a base frame 331, a lead screw and nut pair II 332, a linear guide rail and slider pair III 333, a carriage, and a drive device IV 335. The transverse platform 324 is connected to the base frame 331 through the linear guide rail and slider pair III 333. The nut II 3321 of the lead screw and nut pair II 332 is connected to the carriage, and the carriage is fixedly installed on the base frame 331. The lead screw 3322 of the lead screw and nut pair II 332 is installed on the transverse platform 324 through the bearing seat 3323. The drive device IV 335 consists of a servo motor IV 3351 and a reducer IV 3352. By driving the lead screw and nut pair II 332, the transverse platform 324 can move linearly relative to the base frame 331 along the axial direction of the linear guide rail and slider pair III 333.

[0032] like Figure 1 As shown, the support unit 34 includes a fixed body 341, a movable body 342, and a foot plate 343. The movable body 342 can move up and down relative to the fixed body 341. The foot plate 343 is connected to the movable body 342 by a ball joint. The fixed body 341 of the support unit 34 is arranged and installed around the base frame 331. By driving the different support units 34 to adjust the lifting height, the pitch angle, sway angle, and vertical height position of the base frame 331 can be adjusted.

[0033] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for adjusting the pose of a target with a large aspect ratio using multiple degrees of freedom, characterized in that, Includes the following steps: Step S1: Obtain the target end attitude deviation ( , , , ); in: This is the horizontal displacement adjustment amount; This refers to the vertical adjustment amount. This is the horizontal plane rotation adjustment amount; This is the vertical plane pitch adjustment amount; Step S2: Establish the five-bar model and forward kinematics model of the pose adjustment device; The posture adjustment device includes a main body and support units located on the periphery of the bottom of the main body. The support units are used to adjust the pitch angle, yaw angle, and vertical height of the main body. The main body includes a pitch unit, a rotation unit, and a traverse unit arranged sequentially from top to bottom. Support units are arranged on the periphery of the traverse unit. The pitch unit is used to drive the workbench to perform a swaying motion. The rotation unit is used to drive the pitch unit to perform a circumferential rotation motion. The traverse unit is used for the linear motion of the rotation unit. Step S21: Construct a five-link model sequentially along the end of the target with a large aspect ratio and the pitch, rotation, lateral and support units; Step S22: Establish the representation matrix for each link; Step S23: Construct the forward kinematic transformation matrix based on the product of the coordinate transformations of the five links; Step S3: Based on the forward kinematics transformation matrix, inversely solve the attitude deviation of each motion axis of the pose adjustment device at the target end ( , , , Adjustment amount at time; Step S4: Based on the inverse kinematics result in step S3, adjust each motion axis of the pose adjustment device to achieve a multi-degree-of-freedom pose adjustment of the target end with a large aspect ratio.

2. The method for adjusting the pose of a target with a large aspect ratio according to claim 1, characterized in that, In step S2, the pitch unit, rotation unit, traverse unit, and support unit are respectively provided with a worktable, a rotation table, a traverse table, and a base frame arranged sequentially from top to bottom; the pitch unit is used to drive the worktable to swing around the bearing support axis on the rotation table; the rotation unit is used to drive the rotation table to rotate around the support bearing axis on the traverse table; the traverse unit is used to drive the traverse table to move linearly relative to the base frame; and the support unit is used to adjust the pitch angle, sway angle, and vertical height position of the base frame.

3. The method for adjusting the pose of a target with a large aspect ratio according to claim 2, characterized in that, Step S21 includes the following steps: (1) Establish an initial link coordinate system at the bottom of the support element; Establish the first link coordinate system at the intersection of the support element and the transverse element; Establish a second link coordinate system along the centerline of the transverse unit; A third link coordinate system is constructed at the intersection of the central axis of the pitch arc of the rotary table motion and the central axis of the rotation arc; Construct a fourth link coordinate system at the intersection of the central axis of the pitch arc of the workbench movement and the central axis of the rotation arc; Construct a fifth link coordinate system at the end center point of the target with a large aspect ratio; (2) The initial link coordinate system and the first link coordinate system, the first link coordinate system and the second link coordinate system, the second link coordinate system and the third link coordinate system, the third link coordinate system and the fourth link coordinate system, and the fourth link coordinate system and the fifth link coordinate system are respectively provided with a first link, a second link, a third link, a fourth link, and a fifth link.

4. The method for adjusting the pose of a target with a large aspect ratio according to claim 3, characterized in that, In step S22, the representation matrices of the first to fifth links are established: ； ； ； ； ； in: L 1 is the length of the third link, and it is equal to the distance from the transverse axis to the axis of rotation. It is the joint angle of the third link, and is equal to the rotation angle of the posture adjustment device; It is the joint angle of the fourth link, and is equal to the pitch angle of the posture adjustment device; d 1 is the offset of the first link, and it is equal to the ground clearance of the lateral movement unit; d 2 is the offset of the second link, and it is equal to the distance from the center line of the transverse translation element to the first coordinate system. Distance between axes; d 3 is the offset of the third link, and it is equal to the distance from the third link to the origin of the coordinate system of the third link; d 4 is the offset of the fifth link, and it is equal to the distance from the origin of the coordinate system of the fourth link to the target with the large aspect ratio; L 2 is the length of the fifth link, and it is equal to the length of the target with the large length-to-diameter ratio.

5. The method for adjusting the pose of a target with a large aspect ratio according to claim 4, characterized in that, In step S23, the positive kinematic transformation matrix is: ； in: ; ; ; ； ； ； ； ； ； ； ； 。 6. The method for adjusting the pose of a target with a large aspect ratio according to claim 5, characterized in that, In step S3, the adjustment amount is obtained ( , , , This includes the following steps: Step S31: Assume ,and Each element in the table represents the target value; in: nx , ny , nz They are respectively , , ; ox , oy , oz They are respectively , , ; , , They are respectively , , ; qx , qy , qz They are respectively , , ; Step S32: Based on step S31, solve the simultaneous equations. Solving for: ； Step S33: Based on step S31, solve the simultaneous equations. Solving for: ； Step S34: Based on step S31, solve the simultaneous equations. Solving for: ； Step S35: Based on step S31, solve the simultaneous equations. Solving for: ； in: The attitude deviation of the pose adjustment device at the end point ( , , , The actual adjustment amount of vertical plane lifting during the process; The attitude deviation of the pose adjustment device at the end point ( , , , The actual adjustment amount of horizontal plane lateral movement at that time.

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