A positioner and its swing parameter calibration method

Abstract

A positioner and a method for calibrating its swing parameters belong to the field of positioners, and include a base, on which a linear guide and a ball screw driven by a motor are installed, the linear guide and the ball screw are arranged horizontally, the ball screw is connected to a slide via a nut seat, the slide is slidably connected to the linear guide via a slider, the slide is connected to a right L-shaped connecting plate via a swing mechanism, a V-axis servo motor is vertically installed on the L-shaped connecting plate, the V-axis servo motor is connected to a workbench, the arrangement of the V-axis servo motor and the swing mechanism enables the workbench to swing or rotate around the Z-axis, the workbench can achieve more complex motion trajectories, the flexibility of the workbench is increased, and the application range of the workbench is improved, and the structure of the two linear axes moving into a swing avoids the disadvantages of large torque turntables having large manufacturing difficulty, large volume, and poor rigidity, and has the advantages of compact structure, good rigidity, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of positioners, and in particular to a positioner and a method for calibrating its swing parameters. Background Art

[0002] A positioner is a device widely used in industrial production, mechanical processing, automatic control and other fields. It is a device used to change the position or posture of an object. It can convert one form of motion into another, or change the spatial position of an object to meet different production processes and operational requirements.

[0003] Traditional positioners generally use servo motors + precision reducers to achieve high precision. In order to ensure load stiffness, high-rigidity reducers with large reduction ratios are generally used. However, precision reducers with large reduction ratios and high rigidity are generally expensive and have large installation dimensions. Currently, high-precision swing turntables (such as publication number CN109702645A) have appeared, which are small in overall size.

[0004] However, the existing high-precision swing turntable structure has one end of its spindle seat rotatably connected to the first vertical slide, and the other end is connected to the second vertical slide through a connecting rod, which cannot provide sufficient rigid support. When heavy cutting or high-speed processing is performed, the cutting force is large, which can easily cause deformation of components such as the connecting rod, rotating pair and slide, thereby affecting the processing accuracy; in addition, traditional processing, installation and debugging methods are difficult to accurately guarantee the installation dimensions of each pendulum length in the swing mechanism. The swing accuracy of the existing high-precision swing turntable structure depends on precision manufacturing and precision assembly, which greatly increases the manufacturing cost of the turntable structure. Summary of the invention

[0005] In order to solve the technical problem of poor structural rigidity and stability of the existing high-precision swing turntable in the above-mentioned background technology, the present invention provides a positioner.

[0006] The technical solution of the present invention is as follows: The present invention provides a positioner, including a base, on which a linear guide and a ball screw driven by a motor are installed, the linear guide and the ball screw are arranged horizontally, the ball screw is connected to a slide through a nut seat, the slide is slidably connected to the linear guide through a slider, the slide is connected to a right L-shaped connecting plate through a swinging mechanism, a V-axis servo motor is vertically installed on the L-shaped connecting plate, the V-axis servo motor is connected to a workbench, the arrangement of the V-axis servo motor and the swinging mechanism allows the workbench to swing or rotate around the Z-axis, the workbench can achieve more complex motion trajectory, the flexibility of the workbench is increased, the application range of the workbench is improved, the structure of changing the motion of two linear axes into swinging avoids the disadvantages of large torque turntables, large size, poor rigidity, etc., and has the advantages of compact structure, good rigidity, etc.

[0007] Preferably, the swing mechanism includes a rocker arm and a connecting rod, one end of the connecting rod is rotatably connected to the slide via a first cross roller bearing, the other end of the connecting rod is rotatably connected to the lower end of the rocker arm via a second cross roller bearing, the upper end of the rocker arm is fixedly connected to the L-shaped connecting plate via a connecting sleeve, and the connecting sleeve is rotatably connected to the base. The use of cross roller bearings can withstand larger radial and axial loads while ensuring high precision and low friction of rotation, so that the relative movement between the rocker arm and the connecting rod is smoother and more stable, reducing the motion error caused by bearing wear or clearance, extending the service life of the swing mechanism and improving its motion accuracy, which has obvious advantages in frequent swinging operations.

[0008] Preferably, the connecting sleeve is arranged transversely and perpendicular to the rocker arm, which is beneficial to the uniform transmission of force, and the force transmission path from the rocker arm to the L-shaped connecting plate is more reasonable, thereby reducing stress concentration.

[0009] Preferably, the connecting sleeve and the base are rotatably connected via a turntable bearing, so that the rocker arm can rotate with a stable axis and maintain good stability and repeatability when swinging at different angles, which can effectively improve the work quality in industrial scenarios requiring multi-angle operations. The turntable bearing has high load-bearing capacity, high precision and good rotation performance, which can further enhance the rotation flexibility and stability between the swing mechanism and the base, reduce friction resistance and energy loss during rotation, and can reduce equipment maintenance costs and improve work efficiency for equipment that requires frequent adjustment of the swing angle and long-term continuous operation.

[0010] Preferably, the V-axis servo motor is connected to the workbench through a reducer, and the speed and torque of the motor output can be adjusted according to actual needs so that the workbench can obtain appropriate movement speed and power. The cooperation of the V-axis servo motor and the reducer can accurately adjust the angle and position of the workbench to meet the diverse needs of the workbench movement during the processing or assembly of complex workpieces, and improve the adaptability of the equipment to different process requirements.

[0011] The present invention provides a swing parameter calibration method, which is as follows: a laser interferometer is used to measure the pendulum length parameter and the initial offset angle of the pendulum rod. As the original data, the pendulum length parameters include the distance between the second cross roller bearing and the connecting sleeve in the Z direction , connecting rod length , the distance between the two ends of the connecting rod in the Z direction when the swing arm is in the initial position The PSO algorithm based on the layer-by-layer partition search strategy calibrates the pendulum length parameters and the initial position of the pendulum. The laser interferometer is a high-precision measuring instrument that can accurately obtain the relevant parameters of the pendulum length and the initial offset angle of the pendulum, providing an accurate and reliable data basis for subsequent calibration, making the calibration results closer to the true value, thereby improving the accuracy of the motion control of the entire positioner system and reducing the equipment operation instability or processing errors caused by parameter errors.

[0012] Preferably, the swing mechanism parameters to be measured are and the initial deflection angle of the pendulum As decision variables, they correspond to the four dimensions of the particles respectively. The PSO algorithm based on the layer-by-layer partition search strategy obtains the particle fitness value. The multi-dimensional decision variable setting can comprehensively consider the influence of various parameters of the swing mechanism on its motion characteristics. The PSO algorithm based on the layer-by-layer partition search strategy has a stronger global search capability. By combining the measured data with the algorithm, it can quickly search for a better solution in a complex parameter space. Compared with the traditional single parameter adjustment or local search algorithm, it can more efficiently find the swing parameter combination that meets the requirements, thereby improving the calibration efficiency and accuracy.

[0013] Preferably, the specific process of obtaining the particle fitness value by the PSO algorithm based on the layer-by-layer partition search strategy is as follows: Step 1: Input the design parameters of the swing mechanism As the initial decision variable center, enter the search upper and lower limits , , determine the initial search space , input laser interferometer measurement data, optimize parameters, and set the number of search layers , search space number , and clear the high-quality particle set G, which can provide clear scope definition and starting conditions for subsequent searches; Step 2: In the search space Initializing each particle uniformly and calculating the appropriate value of each particle can enable the algorithm to fully explore the search space in the initial stage. =0; Step 3: Compare search counts With the preset maximum number MAXITE1, such as Go to step 4. If Go to step 7. Step 4: Update the particle position, calculate the fitness value of each updated particle, and execute step 5; Step 5: Update the historical optimal fitness value and position of each particle and execute step 6; Step 6 , execute step 3, and decide whether to update particles or search regions by comparing the number of searches with the preset maximum number of searches. When updating particles, the quality of the solution can be continuously optimized, while the regional search can avoid falling into the local optimal solution; Step 7: Divide equally in each dimension into m regions, and in each region Search for the best particle in the region and save it in the high-quality particle set G. Execute step 8. By equally dividing the search space and searching for the best particle in each region and storing it in the set, the potential optimal solution in different regions can be explored. Step 8. Compare search space numbers With the number of partitions m, such as Go to step 9. If Go to step 10. Step 9 , execute step 2; Step 10: Sort the particles from small to large and select the first , execute step 11; Step 11: Compare the number of search layers With the number of partitions MAXITE2, such as Go to step 12. If Go to step 13. Step 12. Settings , , , plan the search area with the selected particle as the center , clear the high-quality particle set G, set , execute step 2; Step 13, output the best particle in the high-quality particle set, sort and select part of the set particles, and adjust the search area according to the number of search layers to continue searching. The layered partitioning and cyclic iteration method can continuously narrow the search range and approach the global optimal solution. The best particle in the high-quality particle set finally output can provide high-precision results for swing parameter calibration, thereby ensuring the precise motion control of the positioner in actual work, improving the overall performance and work quality of the equipment, and reducing equipment failures and production losses caused by inaccurate parameters.

[0014] It can be seen from the above technical solutions that the advantages of the present invention are: 1. The workbench is connected to the vertically arranged V-axis servo motor, and is connected to the slide table through a swing mechanism. The setting of the V-axis servo motor and the swing mechanism allows the workbench to swing or rotate around the Z-axis. The workbench can achieve more complex motion trajectories, increase the flexibility of the workbench, and improve the scope of application of the workbench. The structure of two linear axes moving into a swing avoids the disadvantages of high torque turntables, such as high manufacturing difficulty, large volume, and poor rigidity, and has the advantages of compact structure and good rigidity.

[0015] 2. The swing mechanism adopts a connecting rod and cross roller bearing structure. The use of cross roller bearings can withstand large radial and axial loads while ensuring high precision and low friction of rotation, making the relative movement between the swing rod and the connecting rod smoother and more stable, reducing the motion error caused by bearing wear or clearance, extending the service life of the swing mechanism and improving its motion accuracy, which has obvious advantages in frequent swing operations.

[0016] 3. Through the multi-dimensional decision variable setting, the influence of various parameters of the swing mechanism on its motion characteristics can be comprehensively considered. The PSO algorithm based on the layer-by-layer partition search strategy has a stronger global search capability. By combining the measurement data with the algorithm, it can quickly search for a better solution in a complex parameter space. Compared with the traditional single parameter adjustment or local search algorithm, it can more efficiently find the swing parameter combination that meets the requirements and improve the calibration efficiency and accuracy. The production personnel use conventional methods to produce and install the swing mechanism. After installation, the real parameters of the swing mechanism can be quickly identified through calibration. These parameters can be used to accurately control and adjust the equipment to ensure the high rotation accuracy of the swing mechanism, while greatly reducing its manufacturing cost.

[0017] 4. First, input relevant parameters to determine the initial search space and clear the high-quality particle set, which can provide clear scope definition and starting conditions for subsequent searches; evenly distribute the initialized particles in the search space and calculate the appropriate value, so that the algorithm can fully explore the search space in the initial stage; by comparing the number of searches with the preset maximum number of times to determine the particle update or regional search, the quality of the solution can be continuously optimized when updating the particles, and the regional search can avoid falling into the local optimal solution; divide the search space equally and search for the best particles in each area and store them in the set, which can explore the potential optimal solutions in different areas; sort and select some of the particles in the set and adjust the search area according to the number of search layers to continue searching. This hierarchical partitioning and cyclic iteration method can continuously narrow the search range and approach the global optimal solution. The best particles in the high-quality particle set finally output can provide high-precision results for the swing parameter calibration, thereby ensuring the precise motion control of the positioner in actual work, improving the overall performance and work quality of the equipment, and reducing equipment failures and production losses caused by inaccurate parameters. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0019] Figure 1 It is a schematic diagram of the overall structure of a positioner according to one or more embodiments of the present invention; Figure 2 A schematic diagram of the rear view structure of a positioner according to one or more embodiments of the present invention; Figure 3 The present invention is a schematic diagram of the positive motion principle of the swing mechanism according to one or more embodiments. Figure 1 ; Figure 4 The present invention is a schematic diagram of the positive motion principle of the swing mechanism according to one or more embodiments. Figure 2 ; Figure 5 The present invention is a schematic diagram of the positive motion principle of the swing mechanism according to one or more embodiments. Figure 3 ; Figure 6 The reverse motion principle of the swing mechanism according to one or more embodiments of the present invention is shown in FIG. Figure 1 ; Figure 7 The reverse motion principle of the swing mechanism according to one or more embodiments of the present invention is shown in FIG. Figure 2 ; Figure 8 A schematic diagram of the effect of parameter H error on swing accuracy according to one or more embodiments of the present invention; Fig. 9 A schematic diagram of the effect of parameter L error on swing accuracy according to one or more embodiments of the present invention; Fig.10 A schematic diagram of the effect of parameter d error on swing accuracy according to one or more embodiments of the present invention; Fig.11 A schematic diagram of the effect of the pendulum rod offset angle on the swing accuracy according to one or more embodiments of the present invention; Fig.12 A schematic diagram of a layer-by-layer partition search strategy according to one or more embodiments of the present invention; Fig.13 A schematic diagram of a particle fitness value acquisition process according to one or more embodiments of the present invention; Fig.14 A schematic diagram of a particle fitness value acquisition process of a PSO algorithm based on a layer-by-layer partition search strategy according to one or more embodiments of the present invention; Fig.15 A schematic diagram of initial laser interference detection of a swing mechanism according to one or more embodiments of the present invention; Fig.16 A comparison diagram of the PSO algorithm of the layer-by-layer partition search strategy according to one or more embodiments of the present invention and the traditional search algorithm for detecting swing mechanism errors; The components represented by the reference numerals in the figure are: 1. Workbench; 2. Rocker arm; 3. U-axis drive motor; 4. Ball screw; 5. Connecting rod; 6. Slide; 7. Linear guide; 8. First cross roller bearing; 9. Second cross roller bearing; 10. Connecting sleeve; 11. Transition connecting plate; 12. Reducer; 13. L-shaped connecting plate; 14. Base; 15. Turntable bearing; 16. V-axis V-axis servo motor 16. DETAILED DESCRIPTION

[0020] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in this specific embodiment. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of them. Based on the embodiments in this patent, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this patent.

[0021] Example 1 In a typical embodiment of the present invention, Figure 1-Figure 2As shown, a positioner is proposed, including: a workbench 1, a rocker 2, a U-axis drive motor 3, a ball screw 4, a connecting rod 5, a slide 6, a linear guide 7, a first cross roller bearing 8, a second cross roller bearing 9, a connecting sleeve 10, a transition connecting plate 11, a reducer 12, an L-shaped connecting plate 13, a base 14, a turntable bearing 15 and a V-axis servo motor 16, wherein the U-axis drive motor 3, the ball screw 4 and the linear guide 7 are all fixedly mounted on the base 14, the ball screw 4 and the linear guide 7 are all arranged horizontally, the ball screw 4 is installed in the linear guide 7, the output end of the U-axis drive motor 3 is connected to one end of the ball screw 4 through a coupling, and a nut seat is threadedly connected to the ball screw 4 so as to pass through the nut seat It is connected to the slide 6, and sliders are installed on both sides of the end surface of the slide 6 close to the ball screw 4. The sliders are slidably connected to the linear guide 7. The slide 6 is connected to the L-shaped connecting plate 13 through a swing mechanism. The swing mechanism includes a first cross roller bearing 8, a connecting rod 5, a second cross roller bearing 9, a rocker arm 2 and a connecting sleeve 10. The outer circle of the first cross roller bearing 8 is fixedly connected to the slide 6, the inner circle of the first cross roller bearing 8 is fixedly connected to one end of the connecting rod 5, the outer circle of the second cross roller bearing 9 is fixedly connected to the lower end of the rocker arm 2, and the inner circle of the second cross roller bearing 9 is fixedly connected to the other end of the connecting rod 5. In the non-working state, the rocker arm 2 is vertically arranged, the connecting rod 5 is horizontally arranged, the rocker arm 2 is perpendicular to the connecting rod 5 and is combined into an L-shaped structure.

[0022] The upper end of the rocker arm 2 is fixed to the rear end of the connecting sleeve 10. The connecting sleeve 10 is arranged horizontally and perpendicular to the rocker arm 2. The front end of the connecting sleeve 10 is fixedly connected to the L-shaped connecting plate 13. The front end of the connecting sleeve 10 is fixedly connected to the inner ring of the turntable bearing 15. The outer ring of the turntable bearing 15 is fixedly installed in the circular hole on the upper side of the base 14. The upper end of the L-shaped connecting plate 13 is fixedly installed with a reducer 12. The reducer 12 is a harmonic reducer. The lower end of the L-shaped connecting plate 13 is fixedly installed with a V-axis servo motor 16. The output shaft of the V-axis servo motor 16 is inserted into the input end of the harmonic reducer. The output end of the harmonic reducer is fixedly installed with a transition connecting plate 11. The workbench 1 is fixedly installed on the upper end of the transition connecting plate 11.

[0023] The V-axis servo motor 16 can drive the workbench 1 to rotate around the Z-axis; the U-axis drive motor 3 drives the workbench ball screw 30 to rotate around the axis through the coupling, thereby causing the slide 6 to move left and right along the linear guide 7. Figure 2The figure shows a reference datum. When the slide 6 moves to the right along the linear guide 7, the connecting rod 5 rotates counterclockwise around the first cross roller bearing 8, and the rocker arm 2 rotates clockwise around the turntable bearing 15, thereby driving the connecting sleeve 10 to rotate clockwise, so that the worktable 1 swings around the Y-axis; when the slide 6 moves to the left along the first linear guide 33, the movement mode is opposite to the above process; the worktable 1 can rotate in two directions, so that the worktable 1 can achieve a more complex motion trajectory, increase the flexibility of the worktable 1, and improve the application range of the worktable 1. This structure that swings through the movement of two linear axes avoids the disadvantages of high torque turntables, large size, and poor rigidity, and has the advantages of compact structure and good rigidity.

[0024] The crossed roller bearing itself has a high rotational accuracy, and the clearance between its rolling elements is controlled within a very small range, which can ensure the high-precision positioning of the workbench 1 during the movement process and meet the demand for high-precision positioning. It also has good performance when running at high speed and can achieve rapid swinging of the workbench 1. The movement process is smooth, which helps to improve work efficiency. The rollers of the crossed roller bearing are arranged at 90 degrees and can withstand large axial and radial loads at the same time. Even if subjected to complex external forces, it can maintain the stability of the structure and ensure the normal operation of the print head. It can also effectively resist the overturning moment caused by external forces or during movement, prevent the workbench 1 from tilting or offsetting, ensure the stability of the posture of the workbench 1 when swinging at multiple angles, and improve the accuracy of the swing.

[0025] Since the inner and outer rings of the crossed roller bearings are relatively small in size and cooperate with the connecting rod, the entire structure is compact and occupies less space, which is conducive to the miniaturization and lightweight design of the equipment. Through the cooperation of the connecting rod and the crossed roller bearing, the workbench 1 can make a small swing along the U-axis direction, which increases the flexibility and adaptability of the equipment and can meet different work requirements. The connecting rod length, bearing clearance and other parameters can be adjusted according to actual needs, which is convenient for optimizing the motion range and accuracy of the workbench 1, so that it can better adapt to different work tasks and working environments.

[0026] Example 2 In another typical embodiment of the present invention, a method for calibrating the swing parameters of a positioner is proposed: The U-axis of the positioner adopts a swing mechanism, and the transmission ratio of the reducer 12 is a fixed value, the rotation angle of the V-axis servo motor 1616 when the machine tool is running The angle of the final output of the workbench 1 The relationship between , the rocker mechanism converts the linear displacement into the swing of the rocker 2.

[0027] There are two types of positional relationships between the first cross roller bearing 8 and the second cross roller bearing 9 , one is that the second cross roller bearing 9 is located on the left side of the first cross roller bearing 8 , and the other is that the second cross roller bearing 9 is located on the right side of the first cross roller bearing 8 .

[0028] It should be noted that the left side and the right side mentioned in this embodiment are both attached. Figure 2 The left and right sides of the front view structure shown in are used as reference.

[0029] After the swing angle of the swing rod 2 is obtained, the actual moving distance of the linear motion pair can be obtained by calculation according to the actual positional relationship between the first cross roller bearing 8 and the second cross roller bearing 9.

[0030] When the second cross roller bearing 9 is located on the right side of the first cross roller bearing 8: like Figure 3 As shown, is the oscillation center of the pendulum shaft, is the rotation pair located on the linear motion pair (i.e. the rotation connection position between the first cross roller bearing 8 and the slide 6), and Through the rotating pair connection (i.e. the swing rod 2 and the connecting rod 5 are connected via the second cross roller bearing 9), it is known that and The distance in the Z direction is H, The length of the rod is L (that is, the length of the connecting rod 5 is L). (i.e. pendulum 2) initial position and (i.e. the distance between the two ends of the connecting rod 5) in the Z direction is d, then Initial position of point on linear motion pair , (i.e. pendulum 2) rotates Corner Point (i.e. Rotation Angular revolute joint The actual point is along the Y-direction line and the revolute pair The Y position corresponding to the intersection point along the Z direction is ,in, for Rotation Angular revolute joint The actual point is along the Y-direction line. At the intersection point along the Z-direction, the geometric relationship shows that: , ,therefore (i.e., the rotation of pendulum 2) The displacement of the linear motion pair (i.e. slide 6) corresponding to the angle It can be obtained from formula (1):

[0031] When d is a negative number (in this case, the rotation pair Towards away direction of movement), such as Figure 4 As shown, is the oscillation center of the pendulum shaft, is a revolute pair located on a linear motion pair. and Through the rotating pair Connection, known and The distance in the Z direction is H, The length of the rod is L. Initial position and The distance in the Z direction is d, then Initial position of point on linear motion pair ; Rotation Corner The Y position of the point is ,in, for Rotation Angular revolute joint The actual point of for The initial point of Rotation Angular revolute joint Along the Z direction and the revolute joint The initial point is at the intersection of the Y-upward line. From the geometric relationship, we can know that: , but ,therefore Rotation Displacement of the linear motion pair corresponding to the angle This is consistent with formula (1).

[0032] When the second cross roller bearing 9 is located on the left side of the first cross roller bearing 8: like Figure 5 As shown, is the oscillation center of the pendulum shaft, is a revolute pair located on a linear motion pair. and Through the rotating pair Connection, known and The distance in the Z direction is H, The length of the rod is L. Initial position and The distance in the Z direction is d, then Initial position of point on linear motion pair , Rotation Corner The Y position of the point is ,in, Rotation Angular revolute joint The actual point is along the Y-direction line and the revolute pair The actual point is at the intersection of the Z-upward line. for Rotation Angular revolute joint The actual point is along the Y-direction line. At the intersection point along the Z-direction, the geometric relationship shows that: , ,therefore Rotation Displacement of the linear motion pair corresponding to the angle It can be obtained from formula (2):

[0033] After the actual moving distance of the linear motion pair is obtained, an inverse calculation can be performed according to the actual positional relationship between the first cross roller bearing 8 and the second cross roller bearing 9 to obtain the swing angle of the swing rod 2.

[0034] Specifically, when the second cross roller bearing 9 is located on the right side of the first cross roller bearing 8, as shown in FIG. Figure 6 As shown, it is known that the linear motion pair moves After the distance, The coordinates can be expressed as (y0-y, H+d), for The horizontal straight line distance in the Y direction can be calculated from this The distance e between The distance between them is f, The distance g between them, for Rotation Angular revolute joint Actual point along the line The points where the lines intersect vertically can be known from the trigonometric relationship. , combined with , can be obtained , then we can find , , and then obtain , Right now

[0035] When the second cross roller bearing 9 is located on the left side of the first cross roller bearing 8, as shown in FIG. Figure 7 As shown, it is known that after the linear motion pair moves the y distance, The coordinates of can be expressed as ( ), for The horizontal straight line distance in the Y direction can be calculated from this The distance e between The distance between , The distance g between them, for Rotation Angular revolute joint Actual point along the line The points where the lines intersect vertically can be known from the trigonometric relationship. , combined with , can be obtained , then we can find , , and then obtain .

[0036] When the swing mechanism moves, according to the swing mechanism parameters , the swing angle Transformation into linear axis displacement When the swing mechanism is running, the displacement of the linear axis , converted to the actual angle of the swing axis , because the actual pendulum length Manufacturing and installation deviations, actual angles From the same theoretical perspective There are pendulum length parameter errors, so it is necessary to analyze the influence of each pendulum length error and initial position error on the angle error, and calibrate the pendulum length parameters and initial position.

[0037] by Figure 2 The swing mechanism shown is taken as the analysis object to analyze the influence of each swing length on the error. Figure 2 In the theoretical initial position of the swing mechanism, the main shaft (the axis of the V-axis servo motor 16) is consistent with the axial direction of the swing rod 2, and the swing rod and the connecting rod are at 90°. At this time, take -9°-21° and calculate the corresponding linear displacement at every 3° interval. The calculation results are shown in Table 1: Table 1

[0038] Add errors of -0.02mm, -0.01mm, 0.01mm, and 0.01mm to the parameters respectively, and use the inverse calculation formula (3) to solve the angle after swinging. Subtract the theoretical angle from the solved angle to obtain the error number of different swing parameter errors at different angles. For details, see Figure 8-Figure 10 As shown, it can be seen that the error of the swing parameter H has a greater impact on the swing accuracy. When the swing angle is 24°, the error of 0.02 mm will produce an error of 15 arc seconds. The error of L has the second largest impact, and the error of d has a smaller impact and can be ignored. At the same time, the influence of different parameter errors on the swing deviation has different trends. The influence of the error of parameter H on the swing deviation is approximately a straight line, and the influence of parameters L and d on the swing deviation is approximately a parabola, but in opposite directions.

[0039] At the same time, during the actual installation, because the spindle axis (the axis of the V-axis servo motor 16) is not parallel to the axis of the pendulum 2, the machine tool is calibrated based on the verticality of the spindle. At this time, the initial state of the pendulum 2 is not vertical. At this time, the offset angle of the pendulum 2 is , then under the premise of eliminating the swing mechanism error, the actual swing angle Should be , the corresponding linear displacement is However, in actual operation, it is often ignored The existence of the axis zero position is , so the actual spool runs to the position , the corresponding angle is , thus causing the swing deviation, assuming that the initial angle offset is -60 arc seconds, -30 arc seconds, 30 arc seconds, and 60 arc seconds, the specific influence of the pendulum offset angle on the swing accuracy is solved in Fig.11 , it can be seen that the initial angle error has little effect on the swing accuracy, and the main impact range is in the negative angle area.

[0040] Since the final accuracy of the swing mechanism is affected by multiple parameters, the influence of each parameter on the accuracy is nonlinear, and the influence trends and laws of different parameters are also different, it is difficult to accurately calibrate each parameter using traditional methods. This embodiment uses laser interferometer measurement data as raw data and combines it with the improved PSO algorithm to optimize the parameters of the swing mechanism. This embodiment uses a layer-by-layer partition search strategy to improve the PSO algorithm. Specifically, Fig.12 As shown, in the initial search space Initialize each particle and iterate After that, the search space Perform partition processing and search each partition The best particle in ,right Sort from small to large and select the first For each selected particle As the center, set the upper and lower limits of the search respectively, and obtain Independent search space , in each space Initialize each particle and iterate After that, for each search space Partition processing is performed for each search space Use the partition strategy to find the front The regional high-quality particles of the All high-quality particles in the And so on, until the optimal solution is found.

[0041] The process of determining the decision variables and search range of the PSO algorithm based on the layer-by-layer partition search strategy is as follows: and the initial offset angle of pendulum 2 As decision variables, they correspond to the four dimensions of the particle respectively, and the design size or the optimal solution obtained during the optimization process is used as the search center ,in is the layer number to search, is the partition number. The upper and lower search boundaries of each decision variable are set according to the processing and manufacturing, assembly conditions, and the number of search layers. The upper and lower limit changes of linear dimensions are taken as , the search range of the first three dimensions of the corresponding particle is ,in , the upper and lower limits of the rotation size are taken , the search range of the fourth dimension of the particle is , in this example, when the upper and lower contraction boundaries of each decision variable are set, Take 0.1, Take 0.0003 (the radian corresponding to 60 arc seconds), and reduce the upper and lower limits proportionally for each subsequent search. times ( ).

[0042] When calculating the fitness function of each particle, Fig.13 As shown, first, according to the design parameters, the swing angles are obtained by using the positive solution formula of the swing mechanism (i.e., the above formula (1) or formula (2)). The corresponding linear displacement ,in The corresponding angle values ​​of the test quantity during calibration are numbered; then, the corresponding swing angles under the particle parameters are obtained by the inverse formula (i.e., the above formula (3)) Next, solve the error corresponding to each angle caused by the inconsistency between the actual swing parameters and the theoretical swing parameters , and With test data Difference Finally, take The maximum value obtained is the final fitness value.

[0043] like Fig.14 As shown in the figure, the specific steps of the particle fitness value acquisition process of the PSO algorithm based on the layer-by-layer partition search strategy are as follows: Step 1: Input the design parameters of the swing mechanism As the initial decision variable center, enter the search upper and lower limits , , determine the initial search space , input laser interference detection data, optimize parameters, and set the number of search layers , search space number , and clear the high-quality particle set G; Step 2: In the search space Initialize each particle uniformly, calculate the appropriate value of each particle, and set =0; Step 3: Compare search counts With the preset maximum number MAXITE1, such as Go to step 4. If Go to step 7. Step 4: Update the particle position, calculate the fitness value of each updated particle, and execute step 5; Step 5: Update the historical optimal fitness value and position of each particle and execute step 6; Step 6 , execute step 3; Step 7: Divide equally in each dimension into m regions, and in each region Search for the best particle in the kernel and save it in the high-quality particle set G, and execute step 8; Step 8. Compare search space numbers With the number of partitions m, such as Go to step 9. If Go to step 10. Step 9 , execute step 2; Step 10: Sort the particles from small to large and select the first , execute step 11; Step 11: Compare the number of search layers With the number of partitions MAXITE2, such as Go to step 12. If Go to step 13. Step 12. Settings , , , plan the search area with the selected particle as the center , clear the high-quality particle set G, set , execute step 2; Step 13: Output the best particle in the high-quality particle set.

[0044] by Figure 2 Take the swing device shown in the figure as an example, the swing mechanism parameters are firstly designed using the design parameters, and then tested by laser interferometer. Figure 2 The error of the swing device, the test results are as follows Fig.15 As shown, the corresponding average deviation data is taken as the detection data used in optimization. Since the laser data will be set to zero starting point error, the corresponding laser deviation data of each point must be subtracted from the deviation corresponding to 0° to obtain the absolute deviation of each measurement point. The specific data is shown in Table 2: Table 2 Swing mechanism angle-linear displacement

[0045] The traditional PSO algorithm and the PSO algorithm with layer-by-layer partition search strategy are respectively called to calibrate the swing parameters. Since the layer-by-layer partition strategy has a large amount of calculation, it is less efficient than the table algorithm. The final error of the search is compared. The algorithm parameter settings and the final results are shown in Table 3: Table 3

[0046] It can be seen that compared with the traditional search strategy, the PSO using the layer-by-layer partition search strategy has higher search accuracy. This is because PSO is more likely to fall into the local optimum when processing high-dimensional data, and the layer-by-layer partition search strategy has stronger global and local search capabilities, so it can obtain better optimization solutions. In order to further verify the effectiveness of the algorithm, the optimization solutions of the two strategies are used to generate test programs to re-detect the errors of the swing mechanism. The test results are shown in Fig.16 ,from Fig.16 It can be seen that the detection results of the data optimized by the layer-by-layer partition search strategy are significantly better than those optimized by the traditional strategy. At the same time, there are still certain errors in the optimized results. This is because in addition to the pendulum length error, the system also has factors such as screw pitch error and installation geometry error. However, the swing parameter calibration method in this embodiment can quickly achieve high-precision calibration of the swing parameters.

[0047] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A positioner, comprising: The base (14) is characterized in that a linear guide (7) and a motor-driven ball screw (4) are installed on the base (14), the linear guide (7) and the ball screw (4) are arranged horizontally, the ball screw (4) is connected to a slide (6) through a nut seat, the slide (6) is slidably connected to the linear guide (7) through a slider, the slide (6) is connected to the right L-shaped connecting plate (13) through a swing mechanism, a V-axis servo motor is vertically installed on the L-shaped connecting plate (13), and the V-axis servo motor is connected to the workbench (1).

2. The positioner according to claim 1, characterized in that: The swing mechanism comprises a swing rod (2) and a connecting rod (5); one end of the connecting rod (5) is rotatably connected to the slide table (6) via a first cross roller bearing (8); the other end of the connecting rod (5) is rotatably connected to the lower end of the swing rod (2) via a second cross roller bearing (9); the upper end of the swing rod (2) is fixedly connected to an L-shaped connecting plate (13) via a connecting sleeve (10); and the connecting sleeve (10) is rotatably connected to a base (14).

3. The positioner according to claim 2, characterized in that: The connecting sleeve (10) is arranged transversely and perpendicular to the swing rod (2).

4. The positioner according to claim 2, characterized in that: The connecting sleeve (10) and the base (14) are rotatably connected via a turntable bearing (15).

5. The positioner according to claim 1, characterized in that: The V-axis servo motor is connected to the workbench (1) via a reducer (12).

6. A method for calibrating swing parameters, used for a positioner as claimed in any one of claims 1 to 5, characterized in that: The details are as follows: A laser interferometer is used to measure the pendulum length parameters and the initial offset angle of the pendulum (2). As the original data, the pendulum length parameter includes the distance between the second cross roller bearing (9) and the connecting sleeve (10) in the Z direction. , connecting rod length , the distance between the two ends of the connecting rod (5) in the Z direction when the pendulum (2) is in the initial position , the PSO algorithm based on the layer-by-layer partition search strategy is used to calibrate the pendulum length parameters and the initial position of the pendulum (2).

7. The swing parameter calibration method according to claim 6, characterized in that: The swing mechanism parameters to be measured and the initial deflection angle of the pendulum (2) As decision variables, corresponding to the four dimensions of particles, the PSO algorithm based on the layer-by-layer partition search strategy obtains the particle fitness value.

8. The swing parameter calibration method according to claim 7, characterized in that: The specific process of obtaining particle fitness value by PSO algorithm based on layer-by-layer partition search strategy is as follows: Step 1: Input the design parameters of the swing mechanism As the initial decision variable center, enter the search upper and lower limits , , determine the initial search space , input laser interferometer measurement data, optimize parameters, and set the number of search layers , search space number , and clear the high-quality particle set G; Step 2: In the search space Initialize each particle uniformly, calculate the appropriate value of each particle, and set =0; Step 3: Compare search counts With the preset maximum number MAXITE1, such as Go to step 4. If Go to step 7. Step 4: Update the particle position, calculate the fitness value of each updated particle, and execute step 5; Step 5: Update the historical optimal fitness value and position of each particle and execute step 6; Step 6 , execute step 3; Step 7: Divide equally in each dimension into m regions, and in each region Search for the best particle in the kernel and save it in the high-quality particle set G, and execute step 8; Step 8. Compare search space numbers With the number of partitions m, such as Go to step 9. If Go to step 10. Step 9 , execute step 2; Step 10: Sort the particles from small to large and select the first , execute step 11; Step 11: Compare the number of search layers With the number of partitions MAXITE2, such as Go to step 12. If Go to step 13. Step 12. Settings , , , plan the search area with the selected particle as the center , clear the high-quality particle set G, set , execute step 2; Step 13: Output the best particle in the high-quality particle set.

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