Workpiece positioning abnormality processing method for servo positioning device and device thereof
By monitoring the torque output value and flexible bearing technology of the servo positioning device, the abnormal workpiece positioning is automatically analyzed and corrected, which solves the problems of poor accuracy and shortened equipment life in the workpiece positioning process of the servo positioning device, and realizes efficient production quality control and equipment maintenance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- YASKAWA ELECTRIC (CHINA) CO LTD
- Filing Date
- 2022-01-07
- Publication Date
- 2026-07-14
AI Technical Summary
Existing servo positioning devices suffer from problems such as poor accuracy, large judgment lag, large human judgment error, severe wear of positioning pins, and shortened equipment life during workpiece positioning, making it difficult to detect and resolve production quality issues in a timely manner.
By monitoring the torque output value of the servo positioning device, the system automatically analyzes workpiece positioning anomalies, uses flexible load-bearing technology to correct positioning errors, reduces wear and scratches on positioning pins, and extends equipment lifespan.
It enables automatic analysis and judgment of production quality problems, reduces the workload of workers, reduces human error, improves product precision and consistency, and extends the service life of equipment.
Smart Images
Figure CN116441818B_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of manufacturing, and in particular to a method and apparatus for determining workpiece positioning anomalies in a servo positioning device. Background Technology
[0002] The NC locator is a servo positioning device developed to meet the flexible production needs of automotive body welding production lines. The NC locator can achieve simultaneous movement along three axes (X, Y, and Z). The X-axis performs longitudinal reciprocating movement, the Y-axis performs lateral reciprocating movement, and the Z-axis performs vertical reciprocating movement. Based on the positioning hole positions of different workpieces, positioning pins and cylinders at the top of the Z-axis or other locations complete the positioning and clamping task, achieving precise positioning.
[0003] In a single production run, the servo positioning device goes through three processes: 1. The servo positioning device starts to bear the vehicle body from an unloaded state (hereinafter referred to as Step No.1, the workpiece loading stage); 2. While the servo positioning device is carrying the vehicle body, the robot performs welding (hereinafter referred to as Step No.2, the workpiece processing stage); 3. The vehicle body on the servo positioning device is removed, and the NC re-enters the unloaded state (hereinafter referred to as Step No.3, the workpiece unloading stage). Figure 1 The output torque curve of the servo positioning device during one production run is shown.
[0004] The main factors contributing to product quality issues can be categorized into three areas: 1. Inadequate precision of the servo positioning device; 2. Inadequate robot precision; and 3. Poor vehicle body precision. Currently, the causes of these quality issues are primarily determined manually, followed by targeted improvements. This results in significant delays in identifying quality problems, is time-consuming and labor-intensive, places high demands on workers, and is prone to errors in judgment.
[0005] Currently, during the welding and other processing of the vehicle body, absolute positioning is achieved using servo positioning pins to ensure that the position of each vehicle remains constant. When the positioning pins wear out, the robot can be compensated for overall offset by a host PLC, which is simple and easy to implement, allowing on-site workers to make corrections themselves. However, when the vehicle body processing precision is poor, the positioning pins may be scratched, affecting positioning accuracy, reducing equipment lifespan, and increasing maintenance costs. Moreover, the significant impact when the vehicle body is transported to the NC locator via the conveyor can affect the accuracy of the positioning pins and the hardware lifespan of the NC locator. In such cases, manual overall offset compensation may sometimes be inaccurate, affecting product precision. Summary of the Invention
[0006] In view of the above problems, one object of this disclosure is to provide a method and apparatus for determining workpiece positioning anomalies in a servo positioning device, so as to automatically analyze and judge the causes of production quality problems and reduce the workload of workers.
[0007] Another objective of this disclosure is to provide a method and apparatus for determining workpiece positioning anomalies in a servo positioning device, so as to reduce the error in determining the cause of production quality problems.
[0008] One objective of this disclosure is to provide a method and apparatus for handling workpiece positioning anomalies in a servo positioning device, so as to automatically correct positioning errors when an anomaly occurs in the vehicle body positioning position, thereby ensuring the workpiece machining accuracy.
[0009] Another objective of this disclosure is to provide a method and apparatus for handling workpiece positioning anomalies in a servo positioning device, so as to reduce the impact of uneven wear and scratches on the positioning pins when the vehicle body positioning position is abnormal, thereby improving the service life of the servo positioning device.
[0010] To achieve at least one of the above objectives, this disclosure adopts the following technical solution:
[0011] A method for determining workpiece positioning anomalies using a servo positioning device includes the following steps:
[0012] Obtain the first torque output value of at least one positioning axis of the servo positioning device for a first predetermined duration;
[0013] Obtain the second torque output value of the positioning axis for a second predetermined duration;
[0014] When the second torque output value deviates from the first torque output value by a predetermined amount, it is determined that the workpiece positioning is abnormal.
[0015] In a preferred embodiment, the first predetermined duration is longer than the second predetermined duration, and the first predetermined duration and the second predetermined duration are consecutive durations.
[0016] In a preferred embodiment, the first predetermined duration is more than five times the second predetermined duration.
[0017] In a preferred embodiment, the first torque output value of each positioning axis of the XYZ axis of the servo positioning device is obtained.
[0018] In a preferred embodiment, the first torque output value and the second torque output value are the maximum torque output values during the workpiece loading stage.
[0019] In a preferred embodiment, the first torque output value is the average of the maximum torque output value during the workpiece loading stage in the first predetermined time period; the second torque output value is the average of the maximum torque output value during the workpiece loading stage in the second predetermined time period.
[0020] In a preferred embodiment, when the second torque output value is greater than the first torque output value by a first predetermined multiple, it is determined that there is an abnormality in the workpiece accuracy; the first predetermined multiple is not less than 1.05 times.
[0021] In a preferred embodiment, when the second torque output value is less than the first torque output value by a second predetermined multiple, it is determined that there is an abnormality at the positioning end of the servo positioning device; the second predetermined multiple is not higher than 0.95 times.
[0022] In a preferred embodiment, the first torque output value and the second torque output value are the minimum torque output values during the workpiece unloading stage.
[0023] In a preferred embodiment, the first torque output value is the average of the minimum torque output values during the workpiece unloading phase in the first predetermined time period; the second torque output value is the average of the minimum torque output values during the workpiece unloading phase in the second predetermined time period.
[0024] In a preferred embodiment, when the second torque output value is less than the first torque output value by a third predetermined multiple, it is determined that there is an abnormality in the workpiece accuracy; the third predetermined multiple is not higher than 0.95 times.
[0025] In a preferred embodiment, when the second torque output value is greater than the first torque output value by a fourth predetermined multiple, it is determined that there is an abnormality at the positioning end of the servo positioning device; the second predetermined multiple is not less than 1.05 times.
[0026] In a preferred embodiment, the first torque output value and the second torque output value are the average torque output values during the workpiece processing stage.
[0027] In a preferred embodiment, the first torque output value is the average torque output value of the workpiece processing stage during the first predetermined time period; the second torque output value is the average torque output value of the workpiece processing stage during the second predetermined time period.
[0028] In a preferred embodiment, when the second torque output value is greater than the first torque output value by a fifth predetermined multiple, it is determined that the output torque of the servo positioning device is too large; the fifth predetermined multiple is not less than 1.05 times.
[0029] A workpiece positioning anomaly detection device for a servo positioning apparatus includes the following steps:
[0030] The first acquisition module is used to acquire the first torque output value of at least one positioning axis of the servo positioning device for a first predetermined duration.
[0031] The second acquisition module is used to acquire the second torque output value of the positioning shaft for a second predetermined time.
[0032] The anomaly determination module is used to determine that the workpiece positioning has become abnormal when the second torque output value deviates from the first torque output value by a predetermined degree.
[0033] This disclosure also provides a method for handling workpiece positioning anomalies in a servo positioning device, comprising the following steps:
[0034] Move the servo positioning device to the target bearing position;
[0035] Obtain the actual load-bearing position of the workpiece in the working area;
[0036] Calculate the offset of the actual load-bearing position of the workpiece relative to the target load-bearing position;
[0037] The offset is provided to the robot performing the target operation on the workpiece to correct the operation trajectory.
[0038] In a preferred embodiment, the workpiece is flexibly supported when the servo positioning device is moved to the target bearing position.
[0039] In a preferred embodiment, when an abnormality is determined at the positioning end of the servo positioning device, the servo positioning device is controlled to flexibly support the workpiece.
[0040] In a preferred embodiment, the servo positioning device has a positioning pin; wherein, in the abnormal handling method, when the servo positioning device moves to the target bearing position, the load applied to the XY bearing on the positioning pin is 1 / 3 to 2 / 3 of the rated load and the Z-axis position remains fixed.
[0041] In a preferred embodiment, the servo positioning device has a positioning pin; wherein, in the abnormal handling method, when the servo positioning device moves to the target bearing position, the load applied to the XY bearing on the positioning pin is 1 / 3 to 2 / 3 of the minimum bearing force for maintaining the position unchanged and the Z-axis position remains fixed.
[0042] In a preferred embodiment, the step of obtaining the actual bearing position of the workpiece in the working area includes:
[0043] After the servo positioning device carries the workpiece, the displacement information of the positioning pin is obtained;
[0044] The actual bearing position of the workpiece is determined based on the displacement information of the positioning pin.
[0045] In a preferred embodiment, the robot is a welding robot.
[0046] As a preferred embodiment, the location anomaly handling method includes:
[0047] Multiple servo positioning devices are moved to the target bearing position, and the positioning pins on the multiple servo positioning devices correspond one-to-one with the multiple target bearing position points.
[0048] Obtain the actual bearing positions of the multiple locating pins after the workpiece is borne;
[0049] The target bearing position points are rotated one by one to the actual bearing position points to determine the rotation center position point and the rotation angle;
[0050] The actual bearing position of the workpiece is calculated based on the rotation center position and the rotation angle.
[0051] As a preferred embodiment, it further includes:
[0052] Establish the ideal load-bearing position of the workpiece in the simulated three-dimensional space, perform robot teaching, and determine the robot teaching trajectory;
[0053] Obtain the actual bearing position of the actual workpiece located in the work area relative to the robot located at the work position;
[0054] Calculate the deviation data of the actual bearing position of the actual workpiece from the ideal bearing position;
[0055] The robot's teaching trajectory is corrected based on the deviation data to obtain the execution process trajectory.
[0056] As a preferred embodiment, the method further includes: moving the robot to the work position and placing the actual workpiece in the work area without deviation using the positioning pin, with the current position of the actual workpiece as the target bearing position.
[0057] This disclosure also provides a workpiece positioning anomaly handling device for a servo positioning device, comprising the following steps:
[0058] A moving module is used to move the servo positioning device to the target bearing position;
[0059] The acquisition module is used to acquire the actual bearing position of the workpiece in the working area;
[0060] The calculation module is used to calculate the offset of the actual bearing position of the workpiece relative to the target bearing position;
[0061] A processing module is used to provide the offset to the robot performing the target operation on the workpiece to correct the operation trajectory.
[0062] Beneficial effects:
[0063] In one embodiment of the workpiece positioning anomaly determination method provided in this disclosure, if the second torque output value is higher than the first torque output value by more than a predetermined threshold, or if the second torque output value is lower than the first torque output value by more than a predetermined threshold, it indicates that the deviation between the first torque output value and the second torque output value is too large. This confirms that a workpiece positioning anomaly has occurred, and an alarm can be triggered to remind on-site workers to conduct an investigation. Therefore, the workpiece positioning anomaly determination method provided in this embodiment can automatically analyze and determine the causes of production quality problems, reducing the workload of workers.
[0064] In one embodiment of the present disclosure, a part positioning anomaly handling method is provided, which reduces friction with positioning pins when the machining accuracy of the vehicle body is poor, thereby increasing the service life of the equipment and reducing maintenance costs.
[0065] In one embodiment of the present disclosure, a part positioning anomaly handling method is provided, in which the servo positioning device provides flexible positioning support for the workpiece, which can absorb the large impact generated when the vehicle body is transported to the NC locator through the conveying equipment, ensure the accuracy of the positioning pin, and improve the life of the NC hardware.
[0066] The part positioning anomaly handling method provided in one embodiment of this disclosure can perform calculations for each vehicle body, ensuring the accuracy of the marking operation for each vehicle body, improving the consistency of product quality, and reducing errors and misoperations caused by manual correction.
[0067] Specific embodiments of this disclosure are disclosed in detail with reference to the following description and accompanying drawings, indicating how the principles of this disclosure can be applied. It should be understood that the embodiments of this disclosure are not limited in scope as a result.
[0068] Features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.
[0069] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, whole, step, or component, but does not exclude the presence or addition of one or more other features, wholes, steps, or components. Attached Figure Description
[0070] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0071] Figure 1 The output torque curve of the servo positioning device during a single production run is shown.
[0072] Figure 2 This is a schematic flowchart of a workpiece positioning anomaly determination method provided in one embodiment of this disclosure;
[0073] Figure 3 This is a schematic flowchart of a workpiece positioning anomaly handling method provided in one embodiment of this disclosure;
[0074] Figure 4 yes Figure 3 A schematic diagram showing the displacement of the target bearing position point and the center position point before and after the workpiece offset;
[0075] Figure 5 yes Figure 4 Equivalent rotation diagram. Detailed Implementation
[0076] To enable those skilled in the art to better understand the technical solutions in this disclosure, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.
[0077] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or may be interposed with another element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or may be interposed with another element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementations.
[0078] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0079] Please see Figure 2 This disclosure provides an embodiment of a method for determining workpiece positioning anomalies in a servo positioning device, comprising the following steps:
[0080] S100: Obtain the first torque output value of at least one positioning axis of the servo positioning device for a first predetermined duration;
[0081] S200: Obtain the second torque output value of the positioning shaft for a second predetermined duration;
[0082] S300: When the second torque output value deviates from the first torque output value by a predetermined degree, it is determined that the workpiece positioning is abnormal.
[0083] In the workpiece positioning anomaly determination method provided in this embodiment, if the second torque output value is higher than the first torque output value by a predetermined threshold, or if the second torque output value is lower than the first torque output value by a predetermined threshold, it indicates that the deviation between the first torque output value and the second torque output value is too large. This confirms that a workpiece positioning anomaly has occurred, and an alarm can be triggered to remind on-site workers to check. Therefore, the workpiece positioning anomaly determination method provided in this embodiment can automatically analyze and determine the causes of production quality problems, reducing the workload of workers.
[0084] Considering that the workpiece undergoes loading, machining, and unloading stages throughout the entire processing phase, the first and second torque output values should be compared using values from the same stage. For example... Figure 1 As shown, during the workpiece loading stage, the servo positioning device has a maximum output torque. During the entire workpiece processing stage, the output torque of the servo positioning device is roughly constant (with slight fluctuations). During the workpiece unloading stage, similar to the loading stage, there is a minimum output torque.
[0085] In this embodiment, the first predetermined duration and the second predetermined duration each include multiple complete processing steps for multiple workpieces, encompassing the processing of multiple workpieces from the loading stage to the unloading stage. The first predetermined duration is longer than the second predetermined duration, and the first predetermined duration and the second predetermined duration are consecutive durations. The first predetermined duration is more than 5 times the second predetermined duration. For example, the first predetermined duration can be more than 5 hours or more than 1 day. In some embodiments, the first predetermined duration and the second predetermined duration can be 1 day, thereby determining whether there are any problems with the production quality on that day.
[0086] In steps S100 and S200, a first torque output value and a second torque output value for each positioning axis of the XYZ axis of the servo positioning device are acquired. The second predetermined duration is later than the first predetermined duration. The first torque output value includes at least one of the maximum torque output value during the workpiece loading stage, the average torque output value during the workpiece machining stage, and the minimum torque output value during the workpiece unloading stage. The second torque output value includes at least one of the maximum torque output value during the workpiece loading stage, the average torque output value during the workpiece machining stage, and the minimum torque output value during the workpiece unloading stage.
[0087] Specifically, the first torque output value can be the average value of each workpiece processing stage, processing stage, or unloading stage obtained through calculation, or the average value of each workpiece processing stage, processing stage, or unloading stage per day. The second torque output value can be the average value of each workpiece processing stage, processing stage, or unloading stage obtained through calculation, or the average value of each workpiece processing stage, processing stage, or unloading stage per day.
[0088] In this embodiment, the first torque output value and the second torque output value are the maximum torque output values during the workpiece loading stage. Specifically, the first torque output value is the average of the maximum torque output values during the workpiece loading stage over a first predetermined time period. The second torque output value is the average of the maximum torque output values during the workpiece loading stage over a second predetermined time period.
[0089] When the second torque output value is greater than the first torque output value by a first predetermined multiple, it is determined that there is an abnormality in the workpiece accuracy; the first predetermined multiple is not less than 1.05 times.
[0090] When the second torque output value is less than the first torque output value by a second predetermined multiple, it is determined that there is an anomaly at the positioning end of the servo positioning device; the second predetermined multiple is not higher than 0.95 times. In this embodiment, the sum of the first and second predetermined multiples is 2. Of course, the first, second, third, fourth, and fifth predetermined multiples can be set as desired and are not fixed values. For example, the workpiece positioning anomaly determination method may also include a setting step for setting at least one of the first, second, third, fourth, and fifth predetermined multiples.
[0091] In this embodiment, the first torque output value and the second torque output value include the average torque output value during the workpiece processing stage. Specifically, the first torque output value is the average torque output value during the workpiece processing stage within a first predetermined time period; the second torque output value is the average torque output value during the workpiece processing stage within a second predetermined time period. Further, when the second torque output value is greater than the first torque output value by a fifth predetermined multiple, it is determined that the output torque of the servo positioning device is too large; the fifth predetermined multiple is not less than 1.05 times.
[0092] The following details a specific application embodiment of this disclosure in order to better understand this disclosure:
[0093] The torque output data of each positioning axis of the servo positioning device is extracted over a period of time (a days, a≥1), with the first 90% of the time period (first predetermined duration) used as reference data and the last 10% of the time period (second predetermined actual duration) used as the data for consideration. (a days can be set according to customer requirements, and the 90% and 10% here can also be changed according to requirements).
[0094] To examine whether there are any abnormalities in the robot welding, the torque output data of each positioning axis in Step No.2 (workpiece processing stage) is used, and the average torque output value (first torque output value and second torque output value) is calculated for each day. The first torque output value and second torque output value of each positioning axis are then compared.
[0095] If, during the latter 10% of the observation period, the daily average torque output value (second torque output value) of Step No. 2 (workpiece processing stage) is greater than 1.1 * the daily average torque output value of Step No. 2 during the first 90% of the observation period (first torque output value), it indicates that the output torque of the servo positioning device (NC locator) is too high and exceeds the normal range during production. If, during the latter 10% of the observation period, the daily average torque output value (second torque output value) is less than or equal to 1.1 * the daily average torque output value of Step No. 2 during the first 90% of the observation period (first torque output value), it indicates that the output torque of the servo positioning device (NC locator) is within the normal range during production, and no positioning abnormalities have occurred.
[0096] If, during the latter 10% of the observation period, the maximum torque output value (second torque output value) of Step No.1 (workpiece loading stage) is greater than 1.1 * the maximum torque output value (first torque output value) of Step No.1 during the first 90% of the observation period, it indicates that the servo positioning device encountered excessive resistance when receiving the workpiece, indicating poor workpiece accuracy.
[0097] If, during the latter 10% of the observation period, the maximum torque output value (second torque output value) for each day in Step No. 1 (workpiece loading stage) is less than 0.9 * the maximum torque output value (first torque output value) for each day in Step No. 1 during the first 90% of the observation period, it indicates that the servo positioning device experiences less resistance when receiving the workpiece, but greater resistance during actual welding. This suggests that the positioning end of the servo positioning device has deformed, becoming more closely aligned with the workpiece position, resulting in reduced overall accuracy and causing a deviation between the taught point and the actual point during spot welding.
[0098] In a specific embodiment, considering that the output torque curves of the workpiece loading stage and the workpiece unloading stage are similar (and move in opposite directions, with the maximum output torque occurring during the workpiece loading stage and the minimum output torque occurring during the workpiece unloading stage, and the output torque reaching an inflection point after experiencing the maximum and minimum output torques), the first torque output value and the second torque output value are the minimum torque output value during the workpiece unloading stage.
[0099] The first torque output value is the average of the minimum torque output values during the workpiece unloading phase within a first predetermined time period, or the minimum torque output value during the workpiece unloading phase each day. The second torque output value is the average of the minimum torque output values during the workpiece unloading phase within a second predetermined time period.
[0100] When the second torque output value is less than a third predetermined multiple of the first torque output value, an anomaly is determined in the workpiece accuracy; the third predetermined multiple is not higher than 0.95 times. When the second torque output value is greater than a fourth predetermined multiple of the first torque output value, an anomaly is determined in the positioning end of the servo positioning device; the second predetermined multiple is not lower than 1.05 times. For example, when the second torque output value is < 0.9 times the first torque output value, an anomaly is determined in the workpiece accuracy, where poor workpiece accuracy may be caused by poor processing accuracy in the preceding production line; when the second torque output value is greater than 1.1 times the first torque output value, an anomaly is determined in the first torque output value.
[0101] This workpiece positioning anomaly determination method also includes an anomaly visualization step, in which pie charts and line graphs are displayed based on the proportion of each fault cause each day. The pie charts clearly show the reasons for reduced processing quality, while the line graphs show the development trend of each fault cause.
[0102] The workpiece positioning anomaly determination method provided in this embodiment has the following advantages:
[0103] 1) By classifying and analyzing the causes of failures, we can roughly deduce the most important reasons for the failure and help customers conduct more targeted inspections. For example, the largest area in a pie chart indicates that the cause is most likely to cause the failure.
[0104] 2) By observing the changes over time as a whole, mismeasurements can be avoided to some extent.
[0105] 3) By monitoring and observing, the optimal maintenance time can be deduced, reducing the number of ineffective maintenance operations, lowering maintenance costs, improving production efficiency, and ensuring production quality. For example, line graphs can be used to observe the trends of fault causes.
[0106] Another embodiment of this disclosure provides a workpiece positioning anomaly determination device for a servo positioning device, comprising: a first acquisition module for acquiring a first torque output value of at least one positioning axis of the servo positioning device for a first predetermined duration; a second acquisition module for acquiring a second torque output value of the positioning axis for a second predetermined duration; and an anomaly determination module for determining that a workpiece positioning anomaly has occurred when the first torque output value deviates from the second torque output value by a predetermined degree.
[0107] Please see Figure 3 This disclosure provides an embodiment of a workpiece positioning anomaly handling method for a servo positioning device, comprising the following steps:
[0108] S5. Move the servo positioning device to the target bearing position.
[0109] S6. Obtain the actual bearing position of the workpiece in the working area.
[0110] S7. Calculate the offset of the actual bearing position of the workpiece relative to the target bearing position.
[0111] S8. Provide the offset to the robot performing the target operation on the workpiece to correct the operation trajectory.
[0112] In this embodiment, the robot performs welding, grinding, or assembly processes on the workpiece. The robot is a welding robot. The vehicle body has support points such as positioning holes. The servo positioning device has positioning pins. Each servo positioning device provides one positioning pin, and multiple positioning pins are inserted into the positioning holes on the vehicle body to position the vehicle body for processing by the robot. When the workpiece position deviates or the processing accuracy is insufficient, the positions of the positioning holes and positioning pins deviate, and the center line of the positioning pin cannot be aligned with the center line of the positioning hole. To avoid scratching or pulling the positioning pin, the positioning pin is designed to float, providing flexible support for the workpiece. This allows the positioning pin to undergo a certain degree of adaptive displacement when the workpiece is placed. The actual position of the abnormally positioned workpiece can be obtained through the planar displacement of the positioning pin, thereby correcting the robot's execution process trajectory.
[0113] In step S5, the workpiece is flexibly supported when the servo positioning device is moved to the target bearing position. In this embodiment, the positioning pin of the servo positioning device can always maintain a flexible bearing state, flexibly supporting each workpiece. This allows for calculations to be performed for each vehicle body, ensuring the accuracy of the marking operation for each vehicle body, improving the consistency of product quality, and reducing errors and misoperations caused by manual correction.
[0114] In one embodiment, when an anomaly is determined at the positioning end of the servo positioning device, the servo positioning device is controlled to provide flexible support for the workpiece. The method for determining the anomaly at the positioning end of the servo positioning device can refer to the positioning anomaly determination method in the above embodiments, and will not be repeated in this embodiment. In this embodiment, before determining that an anomaly is found at the positioning end of the servo positioning device, the servo positioning device provides absolute positioning support. After determining that an anomaly is found at the positioning end of the servo positioning device, the servo positioning device provides flexible support (floating positioning). Calculations are performed for each subsequent vehicle body to ensure the accuracy of the marking operation for each vehicle body, improve product quality consistency, and reduce errors and misoperations caused by manual correction.
[0115] To achieve flexible load-bearing, when the servo positioning device moves to the target load-bearing position, the load applied to the XY bearings on the positioning pins is 1 / 3 to 2 / 3 of the rated load-bearing capacity, while keeping the Z-axis position fixed. Alternatively, when the servo positioning device moves to the target load-bearing position, the load applied to the XY bearings on the positioning pins is 1 / 3 to 2 / 3 of the minimum load-bearing capacity required to maintain the position, while keeping the Z-axis position fixed. In this way, by reducing the load-bearing capacity output by the XY axes (the torque in the previous embodiment), the floating positioning of the vehicle body is achieved. When the vehicle body is placed on multiple positioning pins, the positioning pins adapt to the vehicle body position by changing their own displacement. The fixed Z-axis position ensures the load-bearing height of the vehicle body and prevents the vehicle body from falling.
[0116] Moreover, the output torque of the locating pin is higher than 1 / 3 of the minimum output torque for maintaining the position unchanged (e.g., the output torque in the previous embodiment), which prevents the locating pin from arbitrarily shifting its position or from shifting undesirably, ensuring that only the vehicle body is displaced and that the displacement is not excessive.
[0117] Step S6 is executed as follows: S61, after the servo positioning device carries the workpiece, the displacement information of the positioning pins is obtained; S62, the actual carrying position of the workpiece is determined based on the displacement information of the positioning pins. The positioning pins are located at the desired target carrying position before the carrying vehicle body, and move to the position of the supported point after the carrying vehicle body. The offset information between the positioning pins and the known target carrying position is determined by the displacement information of each positioning pin, thereby determining the actual carrying position of the workpiece.
[0118] like Figure 4 , Figure 5 As shown, more specifically, the location anomaly handling method is performed by the following steps:
[0119] S1': Move multiple servo positioning devices to the target bearing position, with each positioning pin on the servo positioning device corresponding to one of the multiple target bearing position points; the multiple positioning pins establish the work area of the workpiece; the positioning pins are controlled to provide flexible bearing.
[0120] S2' Obtain the actual bearing positions of the multiple positioning pins after the workpiece is supported;
[0121] S31. Rotate multiple target bearing position points one by one to multiple actual bearing position points to determine the rotation center position point and rotation angle;
[0122] S32. Calculate the actual bearing position of the workpiece based on the rotation center position and rotation angle;
[0123] S7. Calculate the offset of the actual bearing position of the workpiece relative to the target bearing position;
[0124] S8. Provide the offset to the robot performing the target operation on the workpiece to correct the operation trajectory.
[0125] In this embodiment, the vehicle body is equivalent to a rigid body that does not change shape. To determine the pattern of position changes of the NC locators, multiple NC locators (with their locating pins) rotate around a distant point (the rotation center point). This point is the rotation center of the multiple NC locators. The rotation center (rotation center point) satisfies the condition that the distance L from this point to the front or rear position of each NC locator is... NC The rotation angle θ of each NC locator remains constant, that is: ①L NC#1 =L' NC#1 ; ②L NC#2 =L' NC#2 ;③L NC#3 =L' NC#3 ④L NC#4 =L' NC#4 ⑤θ NC#1 =θ NC#2 =θ NC#3 =θ NC#4 .
[0126] By deriving and calculating the rotation center based on the above conditions, the rotation center position O(X0,Y0) and rotation angle β=θNC#1 can be calculated. Based on the rotation center position O(X0,Y0) and rotation angle β, the new position (P') of the floating vehicle body can be calculated. The difference between the original position (P point position) and the new position (P' point position) of the vehicle body is the workpiece offset, which is used to transmit to the robot for correction.
[0127] See Figure 1 The method for handling location anomalies also includes the following steps:
[0128] S1. Establish the ideal bearing position of the workpiece in the simulated three-dimensional space, perform robot teaching, and determine the robot teaching trajectory;
[0129] S2. Obtain the actual bearing position of the actual workpiece located in the work area relative to the robot located at the work position;
[0130] S3. Calculate the deviation data of the actual bearing position of the actual workpiece from the ideal bearing position;
[0131] S4. Correct the robot's teaching trajectory based on the deviation data to obtain the execution process trajectory.
[0132] The positioning anomaly handling method also includes step S15: moving the robot to the work position and placing the actual workpiece in the work area without deviation using the positioning pin, with the current position of the actual workpiece as the target bearing position. Step S15 is executed between S1 and S2. In steps S1 to S4, the servo positioning device provides absolute positioning, accurately placing the actual workpiece on the positioning pin to provide accurate data support for subsequent robot corrections. In the subsequent steps S5-S8, the servo positioning device provides flexible bearing.
[0133] Another embodiment of this disclosure provides a workpiece positioning anomaly handling device for a servo positioning device, comprising:
[0134] A moving module is used to move the servo positioning device to the target bearing position;
[0135] The acquisition module is used to acquire the actual bearing position of the workpiece in the working area;
[0136] The calculation module is used to calculate the offset of the actual bearing position of the workpiece relative to the target bearing position;
[0137] A processing module is used to provide the offset to the robot performing the target operation on the workpiece to correct the operation trajectory.
[0138] In the workpiece positioning anomaly handling method and apparatus provided in this disclosure, the NC locator is mainly used to fix the workpiece, and other equipment such as a robot processes the fixed workpiece. During the welding or other processing in Step No. 2, this embodiment can calculate the position and posture of the workpiece based on the torque information read from the X-axis, Y-axis, and Z-axis, and then transmit the information involving parameters such as workpiece position and posture to the controller. The controller then transmits this information to the controller of other equipment, such as the robot, so that the other equipment can adjust its operation based on the information to compensate for the position and posture errors of the fixed workpiece, thereby improving the accuracy of workpiece processing.
[0139] Any numerical values cited herein include all values ranging from a lower limit to an upper limit, increasing by one unit, with at least two units between any lower and any higher value. For example, if the quantity of a component or the value of a process variable (e.g., temperature, pressure, time, etc.) is described as being from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, the purpose is to illustrate that values such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 are also explicitly listed in this specification. For values less than 1, a unit is appropriately considered to be 0.0001, 0.001, 0.01, 0.1, etc. These are merely examples intended for explicit expression, and it can be assumed that all possible combinations of values listed between the minimum and maximum values are similarly explicitly stated in this specification.
[0140] Unless otherwise stated, all ranges include the endpoints and all numbers between them. The terms "approximately" or "about" used with ranges apply to both endpoints of the range. Thus, "approximately 20 to 30" is intended to cover "approximately 20 to approximately 30," including at least the specified endpoints.
[0141] All articles and references disclosed herein, including patent applications and publications, are incorporated herein by reference for various purposes. The term “substantially constitutes…” used to describe a combination should include the identified elements, components, parts, or steps, as well as other elements, components, parts, or steps that do not substantially affect the essential novelty of the combination. The use of the terms “comprising” or “including” to describe combinations of elements, components, parts, or steps herein also contemplates embodiments substantially constituted by such elements, components, parts, or steps. The use of the term “may” herein is intended to indicate that any described attribute included by “may” is optional.
[0142] Multiple elements, components, parts, or steps can be provided by a single integrated element, component, part, or step. Alternatively, a single integrated element, component, part, or step can be divided into multiple separate elements, components, parts, or steps. The use of "a" or "an" to describe an element, component, part, or step does not imply the exclusion of other elements, components, parts, or steps.
[0143] It should be understood that the above description is for illustrative purposes and not for limitation. Many embodiments and applications beyond the provided examples will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this teaching should not be determined by reference to the above description, but rather by reference to the appended claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the inventors have not considered that subject matter as part of the disclosed inventive subject matter.
Claims
1. A method for handling workpiece positioning anomalies in a servo positioning device, characterized in that, The servo positioning device is used to support the workpiece. The servo positioning device has a positioning pin, and the workpiece has a positioning hole into which the positioning pin can be inserted. The positioning pin can flexibly support the workpiece. The servo positioning device's workpiece positioning anomaly handling method includes the following steps: After determining that there is an abnormality at the positioning end of the servo positioning device, the servo positioning device is moved to the target bearing position. During this process, the positioning pin of the servo positioning device provides flexible bearing for the workpiece to eliminate the deviation between the positioning hole and the positioning pin. The center line of the positioning pin and the center line of the positioning hole cannot be aligned. The robot moves to the working position and places the workpiece in the working area with the positioning pin in place without deviation. The current position of the workpiece is the target bearing position. Obtaining the actual bearing position of the workpiece in the working area includes: obtaining the displacement information of the positioning pin after the servo positioning device bears the workpiece; and determining the actual bearing position of the workpiece based on the displacement information of the positioning pin and the known target bearing position. Calculate the offset of the actual load-bearing position of the workpiece relative to the target load-bearing position; The offset is provided to the robot performing the target operation on the workpiece to correct the operation trajectory.
2. The workpiece positioning anomaly handling method for the servo positioning device as described in claim 1, characterized in that, In the abnormal handling method, when the servo positioning device moves to the target bearing position, the load applied to the XY bearing on the positioning pin is 1 / 3 to 2 / 3 of the rated load and the Z-axis position remains fixed.
3. The workpiece positioning anomaly handling method for the servo positioning device as described in claim 1, characterized in that, In the anomaly handling method, when the servo positioning device moves to the target bearing position, the load applied to the XY bearing on the positioning pin is 1 / 3 to 2 / 3 of the minimum bearing force to keep the position unchanged, and the Z-axis position remains fixed.
4. The workpiece positioning anomaly handling method for the servo positioning device as described in claim 1, characterized in that, The robot in question is a welding robot.
5. The workpiece positioning anomaly handling method for the servo positioning device as described in claim 1, characterized in that, The location anomaly handling method includes: Multiple servo positioning devices are moved to the target bearing position, and the positioning pins on the multiple servo positioning devices correspond one-to-one with the multiple target bearing position points. Obtain the actual bearing positions of the multiple locating pins after the workpiece is borne; The target bearing position points are rotated one by one to the actual bearing position points to determine the rotation center position point and the rotation angle; The actual bearing position of the workpiece is calculated based on the rotation center position and the rotation angle.
6. The workpiece positioning anomaly handling method for the servo positioning device as described in claim 1, characterized in that, Also includes: Establish the ideal load-bearing position of the workpiece in the simulated three-dimensional space, perform robot teaching, and determine the robot teaching trajectory; Obtain the actual bearing position of the actual workpiece located in the work area relative to the robot located at the work position; Calculate the deviation data of the actual bearing position of the actual workpiece from the ideal bearing position; The robot's teaching trajectory is corrected based on the deviation data to obtain the execution process trajectory.
7. A workpiece positioning anomaly handling device for a servo positioning apparatus, wherein the servo positioning apparatus is used to support a workpiece, the servo positioning apparatus has a positioning pin, the workpiece has a positioning hole into which the positioning pin can be inserted, and the positioning pin is capable of flexibly supporting the workpiece, characterized in that... The workpiece positioning anomaly handling device for the servo positioning device includes: The moving module is used to move the servo positioning device to the target bearing position after determining that there is an abnormality at the positioning end of the servo positioning device. During this process, the positioning pin of the servo positioning device provides flexible bearing for the workpiece to eliminate the deviation between the positioning hole and the positioning pin, and the center line of the positioning pin and the center line of the positioning hole cannot be aligned. The robot moves to the working position and places the workpiece in the working area with the positioning pin in place without deviation. The current position of the workpiece is the target bearing position. The acquisition module is used to acquire the actual bearing position of the workpiece in the working area, including: acquiring the displacement information of the positioning pin after the servo positioning device carries the workpiece; and determining the actual bearing position of the workpiece based on the displacement information of the positioning pin and the known target bearing position. The calculation module is used to calculate the offset of the actual bearing position of the workpiece relative to the target bearing position; A processing module is used to provide the offset to the robot performing the target operation on the workpiece to correct the operation trajectory.