Method and system for robot position correction data analysis

Abstract

The invention relates to a method and system for robot position correction data analysis. When the robot operator notices that the position of an operation performed by the robot is inaccurate, such as a spot welding position error on a workpiece, which may be caused by mechanical wear of a joint of the robot, the robot operator performs a correction on the position of a tool center point of the robot. Each correction defined by the robot operator alters the position of a particular point in the robot motion program, and optionally alters its pose. The disclosed method provides a graphical display of the history of robot position modifications and analyzes the modification data for specific criteria of distance, direction and frequency of the modifications. When the analysis determines that any single criterion or a combination of multiple criteria is satisfied, a warning is issued that indicates that the robot may have a mechanical wear problem and needs attention.

Description

Technical Field

[0001] The present disclosure relates generally to the field of industrial robot operational diagnostics and, more particularly, to methods and systems for analyzing data defining corrections to a tool center point position performed by a robot operator, providing a graphical display of the position corrections, and alerting the robot operator when the distance, direction, and / or frequency of the corrections on a particular robot meet criteria indicating a possible maintenance issue with the robot. Background Art

[0002] The use of industrial robots to perform a wide range of manufacturing, assembly, and material movement operations is well known. Many of these operations and tasks are performed by articulated robots, such as five- or six-axis robots with servo motors at each rotary joint. These robots are controlled in real time, where the end-tool motion program is broken down into small motion increments, and the robot's controller performs real-time feedback control calculations to calculate the joint motor input commands that move the robot's end-tool according to the specified motion program.

[0003] Kinematics and inverse kinematics (IK) calculations are used to accurately determine the position of the tool center point (TCP) in the workcell coordinate system based on the joint angle positions, and vice versa. However, over time, wear can occur in the robot (such as in the joint bearings), leading to mechanical looseness that, depending on the load conditions on the robot, causes the tool center point position to differ from the position predicted by the kinematic calculations. When this occurs, the robot operator will notice that a particular operation (such as a spot weld) is not being performed at the appropriate spatial location (such as a point on the workpiece).

[0004] When differences in the spatial position of an operation are detected, the robot operator can apply "corrections" to one or more points in the motion program for a specific robot. For example, a correction might define adjusting the position of a specific point in the motion program by a distance defined by the robot operator in the X, Y, and Z directions. Adjustments can also be made to the tool's yaw, pitch, and roll angles. Several robots can perform the same operation on the same type of workpiece using the same motion program. However, because wear varies from robot to robot, the corrections to the tool center point position defined by the robot operator will also be different for each robot.

[0005] As wear on a robot's joints continues to worsen, the need for tool center point corrections becomes more frequent and / or larger. Multiple corrections may also be performed, each incrementally moving the tool center point position further in a common direction. However, these trends may be invisible to robot operators, who are responsible for multiple robots and certainly cannot be expected to memorize and identify specific trends in corrections for each individual robot. Furthermore, to date, there has been no automated way to visualize and analyze tool center point correction data to determine if a deterioration trend is emerging.

[0006] In view of the foregoing, there is a need for an improved method of analyzing tool center point position correction data to determine whether maintenance or other action is necessary. Summary of the Invention

[0007] The present disclosure describes a method and system for analyzing data describing corrections made to a robot's tool center point position. When a robot operator notices positional inaccuracies during an operation performed by the robot (such as a spot weld in the wrong place on a workpiece or a gripper attempting to grasp a workpiece in the wrong location, where the inaccuracy may be caused by mechanical wear in the robot's joints), the robot operator can perform corrections to the robot's tool center point position. Each operator-defined correction changes the position and pose of a specific point in the robot's motion program. The disclosed method provides a graphical display of the robot's positional correction history and analyzes the correction data against specific criteria regarding the distance, direction, and frequency of the corrections. When the analysis determines that any single criterion or combination of criteria is met, a warning is issued, indicating that the robot may have mechanical wear issues and requires attention.

[0008] Additional features of the presently disclosed systems and methods will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is an illustration of an industrial robot showing how mechanical wear of spherical bearings can cause the robot to tilt, resulting in inaccurate positioning of the robot tool.

[0010] Figure 2 is a three-dimensional graph illustrating a robot tool center point position correction performed by a robot operator according to an embodiment of the present disclosure;

[0011] Figure 3 is a conceptual illustration of features and functions of the disclosed method and system for visualization and analysis of robot position correction data according to an embodiment of the present disclosure;

[0012] Figure 4 is a simulated display of a robot position correction data visualization feature according to an embodiment of the present disclosure, wherein a three-dimensional chart illustrates multiple corrections performed at the same point in the robot motion program;

[0013] Figure 5 is a conceptual illustration of a robot position correction data analysis feature according to an embodiment of the present disclosure, wherein multiple corrections performed at increasing frequencies at the same point in a robot motion program trigger an alert;

[0014] Figure 6 is a conceptual illustration of a robot position correction data analysis feature according to an embodiment of the present disclosure, wherein corrections performed in a common direction at multiple points in a robot motion program trigger an alert;

[0015] Figure 7 is a flow chart of a method for visualization and analysis of robot position correction data according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0016] The following discussion of embodiments of the present disclosure related to visualization and analysis of robot position correction data is merely exemplary in nature and is in no way intended to limit the disclosed apparatus and techniques, or their applications and uses.

[0017] Industrial robots are used in a variety of manufacturing, assembly, and material movement operations. While robots can be operated in manual control mode, they are typically provided with predefined motion programs that control the robot's movements. For example, a spot welding robot may have a motion program that defines several sequential positions on a workpiece where spot welds will be performed. A pick-and-place robot may have a motion program that defines a first position and posture for picking up a workpiece and a second position and posture for placing the workpiece. These are very basic examples, and many other types of robotic operations are well known in the art.

[0018] Like any other machine, industrial robots are subject to wear and tear during their service life. Certain types of wear can cause inaccuracies when the robot moves its tool according to its prescribed motion program. This situation is the subject of this disclosure.

[0019] Figure 1is a diagram of an industrial robot 100 illustrating how mechanical wear of the articulated bearings can cause the robot to tilt resulting in inaccurate positioning of the robot's tool. As discussed above and well known in the art, the robot 100 is controlled by a controller 102 to perform tasks described by a motion program. The robot 100 is an articulated robot consisting of a base 110, an "arm" 112, an arm 114, an arm 116, and a tool 120, among other components. In the robot 100, each robot arm is connected to an adjacent arm by a revolute joint, wherein the motion of each joint is controlled by a joint motor, and the actual angular position of each joint is measured by an encoder that feeds back a signal to the controller 102. The controller 102 sends joint motion commands to the joint motors to cause the robot 100 to move the tool 120 according to the specified motion program.

[0020] Joint 130 couples arm 112 to arm 114 and serves as an example for the present discussion. In addition to the joint motor and position encoder described above, joint 130 may also typically include a support bearing. This support bearing is designed to allow rotational movement of arm 114 relative to arm 112 about the axis of joint 130 while preventing other rotational or translational movement at joint 130. Some joints in robot 100 may have more than one support bearing, and each joint may have a different type of joint design depending on the loads it must withstand and other factors. Importantly, regardless of the joint and bearing design details, loosening of the joint / bearing due to mechanical wear can result in unwanted, undesirable motion in the robot joint. For example, loosening of the support bearing of joint 130 can cause arm 114 (and all other downstream arm components) to tilt relative to arm 112 and base 110. This tilt, illustrated by arrow 140, affects the spatial position of tool 120. Of course, other robot designs, numbers of arms / joints, and so on, are equally applicable to this discussion.

[0021] When wear and looseness in the robot 100 is severe enough to cause tilting movement in one or more joints, the robot operator may notice that operations at certain points in the motion program are not being performed in precisely the correct spatial location. For example, a spot weld at a particular point on a workpiece may be slightly off from the desired target location; or a robot gripper (e.g., Figure 1 The robot operator (shown in Figure 1 for tool 120) may attempt to grasp a workpiece at a position that is slightly offset or tilted from the optimal grasping position. When the robot operator notices that the robot is consistently failing to reach a point in the motion program, the operator can perform a position change ("correction") on the robot to adjust the position and / or orientation of the tool center point. This correction instructs the robot to use the adjusted position of the point instead of the original position defined in the motion program.

[0022] Figure 22 is a three-dimensional diagram 200 illustrating a robot tool center point position correction performed by a robot operator according to an embodiment of the present disclosure. Point 210 defines the current position and pose of a particular point "P

[53] " in the motion program, while point 220 defines the position and pose of point P

[53] as adjusted by the correction operation. Figure 2 The correction shown (from point 210 to point 220) only changes the 3D position (x / y / z coordinates) of point P

[53] , as shown by vector 230. Figure 2 In a correction, the yaw, pitch, and roll angles are not changed, although generally, these attitude angles may be changed during a correction operation. Graph 200 shows the positions of points 210 and 220 in 3D space, where the data defining each point includes at least x / y / z coordinates and the yaw / pitch / roll angles. The actual text and values ​​shown on graph 200 are not important. For the purposes of this discussion, a typical correction may result in a small change (such as less than a few millimeters) in each of the x, y, and z positions, while leaving the yaw, pitch, and roll angles unchanged. The robot operator can perform a correction by manually "jogging" the robot's tool center point from its current position (point 210) to its adjusted position (point 220) using the teach pendant.

[0023] In addition to illustrating the concept of corrections, diagram 200 also shows how the corrections are displayed to the robot operator after the fact. This will be discussed further below.

[0024] Figure 2 The corrections shown can be defined for a single point or for multiple points in the motion program of the robot. For a single point in the motion program, corrections can be defined again and again, where each successive correction further adjusts the tool center point position from its previously adjusted position. Thus, point 210 (the current position) can be the original position of point P

[53] defined in the motion program, or point 210 can be the position of point P

[53] adjusted by a previous correction.

[0025] In a typical factory, several robots of the same type may use the same motion program to perform the same operation on their corresponding workpieces. Figure 1 Because the accuracy of the robot's position (as shown) varies for each individual robot, the robot operator will need to make corrections to each robot individually, in the amounts and directions necessary to keep the robot's operation within the specified range. Until now, there has been no effective technology that allows the robot operator to track the corrections made or determine what conclusions, if any, can be drawn from the population of corrections made for a particular robot. The technology of the present disclosure addresses this problem.

[0026] Figure 3is a conceptual illustration 300 of the features and functions of the disclosed method and system for visualization and analysis of robot position correction data according to an embodiment of the present disclosure; Figure 3 Across the top is a timeline 302 showing corrections made to the positions of points in the robot's motion program. At 310, the robot is operating normally, such as after it is initially put into service. Tool center point position corrections are indicated at 312, 314, 316, 318, 320, 322, 324, and 326 on timeline 312. At 330, the robot is no longer operating reliably because it has executed numerous corrections and continues to deviate from the specified range. As discussed below, corrections 312 through 326 are used to illustrate features of the presently disclosed methods and systems.

[0027] In a preferred embodiment, all correction data are eventually collected into a centralized database, which may be located at the site where the robot is located or remotely. Figure 3 In this example, remote data collection devices are directed by cloud server 340. The data collection architecture can be of any suitable design. In one example, each robot within a facility (which can be of many different types, performing many different operations) communicates with its own controller, and each of these controllers communicates with a site data collection device. The site data collection devices at all company facilities then send their data to cloud server 340. Analysis of the corrected data can be performed by the individual controllers, by the site data collection devices, or by cloud server 340.

[0028] A first feature of the present disclosure is a graphical display of one or more corrections. Box 350 is a simulated display screen that includes two different types of correction displays. Graph 352 displays all of the corrections to a particular point in the robot's motion program, showing that many corrections have been made in many different directions. Graph 354 displays a particular correction from graph 352, where the details of that correction can be examined. For example, a robot operator can request a display of corrections to any point or points in the motion program for any robot using a display device that communicates with a site data collection device or cloud server 340. This display feature enables a robot operator to quickly visually view and understand the correction history of a particular robot in a more intuitive manner than a simple tabular listing of correction data. Graphs 352 and 354 are intended only to convey a conceptual idea of ​​the graphical display feature; in Figure 3 The points and text on these diagrams are not intended to be readable. Display features are discussed further below.

[0029] A second feature of the present disclosure is to perform automated analysis of all correction data to determine if the robot has a wear condition that requires attention. Figure 1As discussed, mechanical wear and looseness of the robot's joints can lead to inaccuracies in the position of the robot's tool center point during a motion program. The robot operator then performs corrections to reestablish the desired accuracy at each point in the motion program. Analysis of the correction data can detect position correction trends that indicate compensation for joint wear and looseness.

[0030] Robot joint wear can be detected in correction data in several ways—including the frequency of corrections, the number of points in the motion program that require correction, and the distance and direction of each individual correction—as well as combinations of these factors. All correction data analyses were performed on a single robot basis. Figure 3 Two different types of corrective data analysis are shown that can trigger an alert indicating that the robot needs attention.

[0031] Block 360 illustrates an analysis of the robot correction data that determines that a correction frequency criterion has been exceeded, resulting in a warning being issued to the robot operator. Block 370 illustrates an analysis of the robot correction data that determines that a criterion for multiple points requiring correction in a common direction has been exceeded, resulting in a warning being issued to the robot operator. Graphs 352 and 354 are intended only to convey a conceptual idea of ​​the graphical display features; Figure 3 The points and text on these charts are not intended to be readable. These and other analyses are discussed further below.

[0032] Figure 4 A simulated display 400 illustrates a robot position correction data visualization feature according to an embodiment of the present disclosure, wherein a three-dimensional (3D) chart 410 illustrates multiple corrections performed at the same point in the robot's motion program. Display 400 is presented on a display device available to a robot operator, such as a display device in communication with a site data collection device. Alternatively, display 400 can be presented on any display device in communication with cloud server 340, in which case correction data for any robot at any facility can be viewed. Display 400 can also be presented on a display device connected to a single controller.

[0033] Correction data visualization is typically performed on a single robot basis. For a specific robot, you can view any combination of one or more corrections at one or more points in the motion program. For example, Figure 4Graph 410 in shows all corrections to a particular point ("P[5]") in the robot's motion program, where each correction is represented by a vector from the "current" (starting) position to the adjusted (final) position. Another example might be to display the most recent correction made to each of a plurality of points in the motion program; this example is shown in a later figure. Yet another example combines a timeline with a graphical display of corrections to points by associating events on the timeline with correction vectors in a 3D graph (e.g., by color coding or numerical numbering).

[0034] 3D chart 410 has x, y, and z axes that display coordinate values ​​in a "world" coordinate system, or the coordinate system of the workcell in which the robot operates. Each correction vector is sequentially numbered (1, 2, etc.), allowing the robot operator to understand the spatial relationships and temporal trends of the corrections. When displaying correction data for multiple points in a motion program, the identity of each point is displayed next to its correction vector. The numerical data defining each correction (such as the x / y / z values ​​for the starting and final positions and the yaw / pitch / roll angles) can be turned on or off in display 400. A textual caption 420 is presented on chart 410, listing information such as the robot's identity and the identity of the point displayed in the correction data.

[0035] The robot operator can manipulate the display of the 3D chart 410 to best visualize the correction data—including zooming and panning the display, and rotating the display in 3D as needed to best illustrate the 3D geometric relationships between the corrections.

[0036] Figure 5 Figure 500 is a conceptual illustration of a feature of analyzing robot position correction data, according to an embodiment of the present disclosure, in which multiple corrections performed at increasing frequency at the same point in a robot motion program trigger a warning. A characteristic of corrections related to mechanical wear and looseness of a robot is that wear tends to result in increasing inaccuracies in the tool center point position over time. This characteristic can be easily detected through analysis of position correction data. Figure 5 A timeline 502 is included, illustrating multiple corrections made to the robot's tool center point position over time. Correction 510 is performed shortly after the robot is placed into service. For example, correction 510 could be a minor adjustment to properly calibrate the robot's operation based on the robot's physical setup and the fixtures used in the workcell. Some time later, corrections 520 and 522 are applied to the robot, perhaps to adjust for some mechanical wear that has just begun to set in. Correction 520 is added to the graph containing correction 510, and correction 522 is plotted on the graph alongside corrections 510 and 520, and so on.

[0037] The robot then operates for a period of time without any additional corrections. On the right side of timeline 502, a series of corrections 530 through 538 are performed in rapid succession relative to the robot's overall operating life. The frequency of corrections 530 through 538 likely indicates that the robot's mechanical wear is deteriorating, and therefore the robot should be inspected to determine if preventative maintenance is necessary. Algorithms for triggering warnings based on the frequency of corrections can include several different calculations and criteria. Figure 5 The example shown in has a series of several corrections made to a single point in the motion program. The warning can be triggered by detecting two or more corrections to the same point separated by a time interval less than a specified value. Figure 5 A warning can also be triggered by detecting a number of corrections (e.g., 3 or 4) with an average time interval less than a specified value. Other similar calculations can also be used for this frequency-based warning, including frequency-based calculations that take into account the frequency of corrections to multiple points on a particular robot (not just the frequency of corrections to a single point).

[0038] An alert is triggered when the algorithm detects that alert criteria (e.g., frequency of remediation) have been met. The alert indicates which robot is affected and information about the remediation that triggered the alert. Preferably, the alert is sent to at least the robot operator responsible for the affected robot (e.g., via a pop-up message sent to a display device connected to the site's data collection equipment) and / or by displaying a message or emitting an audio or visual indication on the controller of the affected robot. Alerts can also be sent to other recipients—such as the quality or manufacturing department, maintenance department, etc., of the company operating the robot.

[0039] Figure 5 The timeline 502 is shown for illustration purposes only. It should be understood that the analysis of the correction data is performed automatically, such as by algorithms running on site data collection devices or cloud servers. However, alerts triggered by the analysis can be used Figure 5 The format of the display (with time axis 502) or the previous Figure 4 The robot operator can automatically provide a graphical display of the correction data in one of the formats discussed for visual review.

[0040] Figure 66 is a conceptual illustration 600 of a robot position correction data analysis feature in accordance with an embodiment of the present disclosure, wherein corrections performed in a common direction at multiple points in a robot motion program trigger an alert. A 3D chart 602 shows three corrections; a correction 610 made to a first point P[5], a correction 620 made to a second point P[6], and a correction 630 made to a third point P[7]. Points P[5], P[6], and P[7] are three points in a particular robot's motion program; for example, they may be locations where the robot performs spot welds.

[0041] exist Figure 6 As can be seen in graph 602, corrections 610, 620, and 630 are made in a substantially common direction. That is, the vectors of corrections 610 and 620 are within a few degrees of parallel, as are corrections 620 and 630. When multiple points in a robot's motion program require corrections made in a substantially common direction, this likely indicates that mechanical wear conditions are causing the robot to wobble or tilt. This is another analysis that can be used to trigger a warning. Algorithms that trigger warnings based on corrections made in a common direction at multiple points can include several different calculations and criteria. For example, the minimum number of points included in the analysis and the maximum directional difference in the correction vectors are configurable parameters that can be defined based on the application.

[0042] Figure 6 The 3D graph 602 shown above is for illustration purposes only. As described above, the analysis of the correction data is performed automatically by an algorithm. However, the warnings triggered by the analysis can be used Figure 6 The robot operator can then automatically provide a graphical display of the correction data in the displayed format (3D chart 602) or one of the other formats discussed above for intuitive viewing by the robot operator.

[0043] Other criteria for triggering a warning can also be defined, such as the distance of a single correction exceeding a predefined criteria. Other warning criteria can also be defined as appropriate, involving a single point or multiple points in the motion program and evaluating the distance, direction and frequency of the corrections.

[0044] Figure 7 700 is a flowchart of a method for visualizing and analyzing robot position correction data according to an embodiment of the present disclosure. The steps of flowchart 700 are performed using the site data collection device or cloud server 340 discussed above, and a display device connected to one of the above devices.

[0045] At block 702, correction data is collected for at least one robot. As previously discussed, corrections performed on each robot and controller are transmitted to a site data collection device, which stores correction data for all robots at the site, and preferably also to a cloud server, which stores all correction data for all sites in the enterprise. For each correction, the correction data includes the identity of the robot and motion program involved, the identity of one or more points modified in the correction, and the magnitude of the change in the x / y / z position and yaw / pitch / roll attitude of the one or more points.

[0046] At block 704, the correction data is displayed upon request of the robot operator or other user. The display of the correction data is as follows: Figure 3 and Figure 4 As shown in the figure and described in the corresponding discussion, a robot operator or other user can request the display of one or more corrections for any robot at the site or for which correction data is stored in the cloud server. A single correction to a single point, multiple corrections to the same point in a motion program, and corrections to multiple points in a motion program are all examples of how a user can select to display correction data.

[0047] At block 706, the correction data is continuously and automatically analyzed. As previously discussed, the correction data analysis is performed with respect to predefined criteria, such as the frequency of corrections that will trigger an alert and the criteria for corrections made to multiple points in a substantially common direction. Different criteria can be defined for different types / models of robots, for different motion programs, etc. These criteria can be configured at the site level and / or at the enterprise level, as appropriate. The correction data analysis at block 706 can be performed continuously in real time, for each robot after a correction is performed, or periodically (such as every hour).

[0048] At decision diamond 708, a determination is made as to whether any warning criteria have been met in the analysis at block 706. When no warning criteria have been met, the process returns to block 702 to continue corrective data collection. When any robot meets a warning criterion at decision diamond 708, a corresponding warning is sent at block 710. The warning can be an audible or visual signal at the controller, an email or pop-up message, a push notification, any combination of these, or other communication technology. The purpose of the warning is to notify appropriate personnel that the corrective data analysis indicates that mechanical wear may have caused looseness in the joints of at least one affected robot and that inspection and / or maintenance should be performed.

[0049] From blocks 704 and 710, the process loops back to block 702 where correction data is collected each time a robot operator performs a correction for any robot.

[0050] Throughout the preceding discussion, various computers and controllers have been described and implied. It should be understood that the software applications and modules of these computers and controllers are executed on one or more electronic computing devices having processors and memory modules. Specifically, this includes Figure 1 The controller 102, the site data collection device, and the above Figure 3 Specifically, the processors in these devices are configured to perform the above-mentioned robot correction data collection, analysis and display functions.

[0051] Although various exemplary aspects and embodiments of the method and system for visualization and analysis of robot position correction data have been discussed above, those skilled in the art will recognize modifications, permutations, additions, and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced be construed to include all such modifications, permutations, additions, and sub-combinations as come within the true spirit and scope of the claims.

Claims

1. A method for analyzing robot position correction data, the method comprising: collecting correction data for the robot, wherein the correction data includes one or more corrections, each correction being a robot operator-defined change to a tool center point position at a point in a motion program; upon user request, displaying the corrected data on a display device; analyzing the correction data on a computer having a processor and memory using an algorithm configured to determine whether warning criteria have been met, wherein the warning criteria are defined in terms of correction distance, direction, and frequency; and An alert is sent when the alert criteria have been met.

2. The method according to claim 1, wherein Each correction is defined by the robot operator using the teach pendant to command the robot to move the tool center point to a new position, which is saved and thereafter used for that point in the motion program.

3. The method according to claim 2, wherein: Each correction also includes changes to the pose of the tool center point at that point in the motion program.

4. The method according to claim 3, wherein: Each correction changes the position and / or orientation of the tool center point relative to the original position and orientation of the point in the motion program, or relative to a previously defined correction.

5. The method according to claim 1, wherein Displaying the correction data includes displaying vectors on a three-dimensional graph, the vectors illustrating changes made to the tool center point position for the one or more corrections.

6. The method according to claim 5, wherein: The three-dimensional graph includes a textual display of position and pose data regarding the points at the head and tail of each vector.

7. The method according to claim 1, wherein One of the warning criteria determines whether the correction data includes multiple corrections made to a particular point of the motion program at a frequency exceeding a threshold, the frequency being defined as the number of corrections per unit time.

8. The method according to claim 1, wherein One of the warning criteria determines whether the correction data includes multiple corrections made to a particular point in the motion program in a common direction, wherein the common direction is defined as an angle of deviation from parallelism of the multiple corrections being below a threshold.

9. The method according to claim 1, wherein One of the warning criteria determines whether the correction data includes corrections made to a plurality of points in the motion program in a common direction, wherein the common direction is defined as an angle of deviation from parallelism of the corrections being below a threshold.

10. The method according to claim 1, wherein Sending a warning includes providing an audible or visual indication on a controller of the robot, or sending an email or text message or push notification to the user or robot operator.

11. The method according to claim 10, wherein: The warning includes an indication that the robot may be experiencing mechanical wear that causes the correction data to trigger the warning, and a description of which warning criteria are met.

12. The method according to claim 1, wherein The correction data is collected and analyzed for multiple robots by a site data collection device located at the same site as the robots or by a cloud server located at another location, and the warning criteria are configured for each robot model and running motion program.

13. A method for analyzing robot position correction data, the method comprising: collecting correction data for the plurality of robots on a data collection device in communication with a controller of each robot, wherein the correction data includes a plurality of corrections, each correction being a robot operator-defined change to a tool center point position at a point in a motion program for one of the robots; upon user request, displaying the modified data on a display device, including displaying one or more modified vectors on a three-dimensional graph; analyzing, at the data collection device, the correction data using an algorithm configured to determine whether warning criteria have been met, wherein the warning criteria are defined based on the correction distance, direction, and frequency of the corrections on each robot; and An alert is sent when the alert criteria have been met, wherein the alert lists the affected robots and includes an indication that the affected robots may be experiencing mechanical wear that caused the correction data to trigger the alert, and a description of which alert criteria have been met.

14. The method according to claim 13, wherein One of the warning criteria determines whether the correction data includes multiple corrections made to a specific point in the motion program at a frequency exceeding a threshold, wherein the frequency is defined as the number of corrections per unit time, and one of the warning criteria determines whether the correction data includes corrections made to one or more points in the motion program in a common direction, wherein the common direction is defined as an angle of deviation from parallelism of the corrections being below a threshold.

15. A system for analyzing robot position correction data, the system comprising: Multiple robots and robot controllers; as well as a computer having a processor and a memory and in communication with the controller, the computer being configured to: collecting correction data for the robots, wherein the correction data includes one or more corrections, each correction being a robot operator-defined change to a tool center point position at a point in a motion program for one of the robots; upon user request, displaying the corrected data on a display device; analyzing the correction data to determine whether warning criteria have been met, wherein the warning criteria are defined based on the correction distance, direction, and frequency of the corrections on each robot; and An alert is sent when the alert criteria have been met.

16. The system according to claim 15, wherein: Each correction is defined by the robot operator using a teach pendant to command one of the robots to move the tool center point to a new position, which is saved and thereafter used by the one robot for that point in the motion program.

17. The system according to claim 16, wherein: Each correction changes the tool center point position and / or tool center point pose relative to the original position and pose of the point in the motion program, or relative to a previously defined correction.

18. The system according to claim 15, wherein: Displaying the correction data includes displaying vectors on a three-dimensional graph, the vectors illustrating changes made to the tool center point position for one or more corrections, and wherein the three-dimensional graph includes a textual display of position and pose data for points at the head and tail of each vector.

19. The system of claim 15, wherein: One of the warning criteria determines whether the correction data includes multiple corrections made to a particular point in the motion program for a single robot at a frequency exceeding a threshold, the frequency being defined as the number of corrections per unit time.

20. The system of claim 15, wherein: One of the warning criteria determines whether the correction data includes corrections made to a particular point or points in the motion program for a single robot in a common direction, wherein the common direction is defined as an angle of deviation from parallelism of the corrections being below a threshold.

21. The system of claim 15, wherein: Sending a warning includes providing an audible or visual indication on the controller of the affected robot, or sending an email or text message or push notification to the user or robot operator, and the warning includes an indication that the affected robot may be experiencing mechanical wear that causes the correction data to trigger the warning, and a description of which warning criteria are met.

22. The system of claim 15, wherein: The computer is a site data collection device located at the same site as the plurality of robots or a cloud server located at another location, and the warning criteria are configured for each robot model and running motion program.

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