Workpiece profile measurement method and device based on intelligent slave station and readable medium

Abstract

This invention relates to the field of measurement technology, specifically to a workpiece contour measurement method, apparatus, and readable medium based on an intelligent slave station. The method includes: constructing measurement posture constraints; generating a contour scanning path based on the contour curve of the workpiece to be measured and the measurement posture constraints; continuously scanning the workpiece to be measured along the contour scanning path according to the measurement posture constraints to obtain measurement data distributed along the contour scanning path, and simultaneously acquiring the pose data of the robot's motion during the continuous scanning process; acquiring the initial time deviation between devices and the data transmission delay in the communication link when the workpiece contour measurement system starts, and aligning the pose data and measurement data in time according to the initial time deviation and transmission delay; and then spatially mapping the time-aligned pose data and measurement data to obtain contour measurement data, thereby solving the problem that it is difficult to establish a correspondence between measurement data and specific spatial positions and measurement directions during continuous contour measurement.

Description

Technical Field

[0001] This invention relates to the field of measurement technology, and specifically to a workpiece contour measurement method, device, and readable medium based on an intelligent slave station. Background Technology

[0002] In industrial manufacturing, equipment assembly, and quality inspection applications, accurate workpiece dimensions are a crucial foundation for achieving high-quality machining and assembly. For workpieces with free-form surfaces or irregular contours, traditional offline measurement methods often require complex clamping and datum alignment processes, making it difficult to balance measurement flexibility with on-site adaptability.

[0003] Existing workpiece measurement technologies mainly include vision-based non-contact measurement and contact measurement. While vision-based measurement solutions offer high measurement efficiency, their stability and accuracy are easily affected by complex lighting environments, reflective metal surfaces, or occlusion conditions. Furthermore, multi-camera or structured light systems are typically costly and complex to calibrate, making them unsuitable for rapid deployment in industrial settings.

[0004] In contact measurement solutions, 3D edge finders, as a simple and reliable measuring device, are widely used in CNC machine tools and industrial robotics. In existing robot measurement applications, 3D edge finders are typically used for locating workpiece reference points or feature points. Their measurement process is based on a trigger event, outputting the corresponding measurement value when the probe contacts the workpiece surface. This measurement value is essentially the comprehensive displacement at the moment of triggering and does not directly contain displacement component information in various spatial directions.

[0005] In applications such as workpiece calibration or datum establishment, measurement tasks typically involve pre-setting the robot's motion direction, causing the edge finder to contact the workpiece surface along a known and controlled motion direction, thus triggering the measurement result to correspond to the expected measurement direction. Under these application conditions, the robot's motion direction during the measurement process has clear prior constraints, and a single trigger measurement can meet the accuracy requirements for datum point positioning or calibration. Therefore, 3D edge finders are widely used in discrete measurement scenarios such as workpiece calibration and datum establishment.

[0006] With increasing measurement demands, practical workpiece contour measurement applications have evolved from discrete trigger measurements to continuous scanning processes along the workpiece contour. Unlike reference calibration applications, continuous contour measurement requires the robot's end effector to move along a complex contour path, with its direction of movement constantly changing along the scanning path. However, the measurement results from 3D edge finders primarily reflect the contact state at the moment of triggering, making it difficult to directly characterize the specific spatial measurement direction. Under these measurement conditions, without unified constraints and coordinated management of the robot's motion state and measurement data, it is difficult to establish a clear correspondence between the results of a single trigger measurement and the contour position and measurement direction, thus increasing the complexity of the contour measurement data.

[0007] To achieve measurement tasks along the workpiece contour, it is typically necessary to simultaneously acquire 3D edge finder measurement data and robot end-effector pose information during robot movement, and then process them uniformly to establish the correspondence between measurement data and spatial position. As measurement tasks evolve from discrete measurement to continuous contour scanning, the requirements for data acquisition, timing coordination, and data processing consistency in measurement systems are further increasing.

[0008] However, in the existing robot measurement system architecture, sensor data acquisition and robot motion control are mostly completed by different modules, and there is a lack of a unified data management and coordination mechanism between the two. The measurement process relies to a certain extent on manual teaching and manual configuration, making it difficult to achieve unified management and automated collaborative processing of measurement data and motion data at the system level. Summary of the Invention

[0009] The purpose of this application is to provide a workpiece contour measurement method, device, and readable medium based on an intelligent slave station to address the aforementioned technical problems.

[0010] In a first aspect, the present invention provides a workpiece contour measurement method based on an intelligent slave station, applied to a workpiece contour measurement system. The workpiece contour measurement system includes a robot, a 3D edge finder, and an intelligent slave station. The 3D edge finder is installed at the end of the robot, and the intelligent slave station is communicatively connected to both the robot controller and the 3D edge finder. The method includes the following steps:

[0011] By constructing measurement direction constraints, roll degree of freedom constraints, and preload displacement constraints, the measurement attitude constraints are obtained.

[0012] Obtain the contour curve of the workpiece to be measured, and generate a contour scanning path based on the contour curve and measurement posture constraints;

[0013] The robot continuously scans the workpiece along the contour scanning path according to the measurement posture constraints, and obtains the measurement data distributed along the contour scanning path. At the same time, the robot's pose data during the continuous scanning process is also acquired.

[0014] The initial time deviation between the intelligent slave station and the 3D edge finder when the workpiece contour measurement system is started is obtained, as well as the transmission delay of the measurement data in the communication link between the intelligent slave station and the 3D edge finder. The pose data and measurement data are time-aligned according to the initial time deviation and transmission delay to obtain aligned pose data and aligned measurement data.

[0015] Spatial mapping is performed on the aligned pose data and the aligned measurement data to obtain contour measurement data.

[0016] As a preferred option, establish a tool coordinate system. and workpiece coordinate system and in the tool coordinate system The displacement trigger direction of the 3D edge finder is defined as the tool axis. ;

[0017] Measurement direction constraints specifically include:

[0018] In response to the availability of the normal n to a local surface region of the workpiece to be measured, the tool axis is set... It remains parallel to the normal n of a local area on the surface of the workpiece to be measured;

[0019] In response to the fact that the normal n of a local surface region of the workpiece to be measured is unavailable, the tool axis is set to... With workpiece coordinate system The Z-direction maintains the first preset included angle setting, and the tool axis Always pointing to the inside of the neighborhood of the workpiece contour being measured;

[0020] Roll freedom constraints specifically include: ensuring the 3D edge finder rotates around the tool axis. Its rotation angle remains constant or changes according to a preset pattern;

[0021] Preload displacement constraint, specifically including: setting preload displacement and safety clearance, in response to determining the distance between the 3D edge finder and the surface of the workpiece along the tool axis. If the distance in the direction is not greater than the preload displacement or the safety clearance, then the measurement is triggered.

[0022] Preferably, the contour curve of the workpiece to be measured is obtained, and a contour scanning path is generated based on the contour curve and measurement posture constraints, specifically including:

[0023] Extract the contour curve of the workpiece from the process model of the workpiece to be tested;

[0024] According to the preload displacement or safety clearance along the tool axis The direction of the offset curve is used to obtain the offset path;

[0025] The offset path is segmented based on the curvature of the contour curve to obtain the segmented offset path.

[0026] Set the desired point density, and based on the curvature of the contour curve and the desired point density, set the scanning speed for each scanning segment of the segmented offset path to obtain the contour scanning path.

[0027] Preferably, the initial time deviation between the intelligent slave station and the 3D edge finder is obtained when the workpiece contour measurement system starts, as well as the transmission delay of the measurement data in the communication link between the intelligent slave station and the 3D edge finder. The pose data and measurement data are then time-aligned based on the initial time deviation and transmission delay to obtain aligned pose data and aligned measurement data, specifically including:

[0028] Obtain the system clock of the intelligent slave station and the local clock of the 3D edge finder. Calculate the initial time deviation between the intelligent slave station and the 3D edge finder when the workpiece contour measurement system starts, based on the system clock of the intelligent slave station and the local clock of the 3D edge finder, as shown in the following formula:

[0029] ;

[0030] in, Indicates the initial time deviation. This indicates the system clock of the intelligent slave station. This indicates the local clock of the 3D edge finder;

[0031] During the initialization phase of the workpiece contour measurement system, the local transmission and reception times of the communication data between the intelligent slave station and the 3D edge finder, recorded based on the local time reference, are acquired. The transmission delay of the measurement data in the communication link between the intelligent slave station and the 3D edge finder is calculated based on the local transmission time, local reception time, and initial time deviation, as shown in the following formula:

[0032] ;

[0033] in, Indicates transmission delay. Indicates the local reception time. Indicates the local transmission time;

[0034] The timestamp corresponding to each pose data and measurement data is determined based on the transmission delay and initial time deviation.

[0035] All pose data and measurement data are time-aligned based on the timestamps to obtain aligned pose data and aligned measurement data.

[0036] Preferably, the aligned pose data and the aligned measurement data are spatially mapped to obtain contour measurement data, specifically including:

[0037] Establish the transformation relationship between the robot coordinate system and the edge finder measurement coordinate system, and transform the aligned pose data to the edge finder measurement coordinate system according to the transformation relationship to obtain the tool pose data of the 3D edge finder;

[0038] The measurement direction is determined based on the measurement posture constraints, and the contour measurement data is calculated along the measurement direction based on the tool pose data and the aligned measurement data.

[0039] Preferably, the method also includes: removing abnormal data from the contour measurement data. The measurement points corresponding to the abnormal data include measurement points that have not been effectively triggered, measurement points that exceed the preset range, measurement points with abnormally abrupt changes in the distance between adjacent points, and measurement points that are inconsistent with the robot's motion state.

[0040] Secondly, the present invention provides a workpiece contour measurement device based on an intelligent slave station, applied to a workpiece contour measurement system. The workpiece contour measurement system includes a robot, a 3D edge finder, and an intelligent slave station. The 3D edge finder is installed at the end of the robot, and the intelligent slave station is communicatively connected to both the robot controller and the 3D edge finder. The device includes:

[0041] The measurement attitude constraint construction module is configured to construct measurement direction constraints, roll degree of freedom constraints, and preload displacement constraints to obtain measurement attitude constraints.

[0042] The scanning path generation module is configured to acquire the contour curve of the workpiece to be measured and generate a contour scanning path based on the contour curve and measurement posture constraints.

[0043] The scanning module is configured to continuously scan the workpiece under test along the contour scanning path according to the measurement posture constraints, obtain measurement data distributed along the contour scanning path, and acquire the pose data of the robot's motion during the continuous scanning process.

[0044] The data alignment module is configured to acquire the initial time deviation between the intelligent slave station and the 3D edge finder when the workpiece contour measurement system starts, as well as the transmission delay of the measurement data in the communication link between the intelligent slave station and the 3D edge finder, and to perform time alignment of the pose data and the measurement data according to the initial time deviation and the transmission delay to obtain aligned pose data and aligned measurement data.

[0045] The data mapping module is configured to spatially map the aligned pose data and the aligned measurement data to obtain contour measurement data.

[0046] Thirdly, the present invention provides an electronic device including one or more processors; and a memory for storing one or more programs, which, when executed by one or more processors, cause the one or more processors to implement the method as described in any implementation of the first aspect.

[0047] Fourthly, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method as described in any of the implementations of the first aspect.

[0048] Fifthly, the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the method as described in any of the implementations in the first aspect.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] (1) The workpiece contour measurement method based on intelligent slave station proposed in this application applies a unified constraint on the robot's motion direction and measurement posture during the measurement process, and introduces an intelligent slave station with data acquisition, timing coordination and data management capabilities to realize the synchronous acquisition and matching of 3D edge finder measurement data and robot motion data. This solves the problem that it is difficult to establish a correspondence between measurement data and specific spatial position and measurement direction during continuous contour measurement, and provides systematic support for the acquisition of workpiece contour information.

[0051] (2) The workpiece contour measurement method based on intelligent slave station proposed in this application applies measurement direction constraints, rolling degree of freedom constraints and pre-pressure displacement constraints to the robot end posture, so that the 3D edge finder can complete the measurement trigger while moving along the contour scanning path, and ensures the consistency of measurement direction during scanning, improves motion smoothness, and enables the 3D edge finder to trigger stably.

[0052] (3) The workpiece contour measurement method based on intelligent slave station proposed in this application introduces intelligent slave station to calculate the clock error and transmission delay between different devices. This enables the intelligent slave station to bind the measurement data and robot pose data under the same time reference during the workpiece contour measurement process, forming a time-consistent and spatially corresponding measurement data unit. This avoids the data mismatch problem caused by the transmission delay of communication or the difference of device clocks, and provides a reliable data foundation for the comprehensive processing of subsequent contour measurement data. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a flowchart illustrating a workpiece contour measurement method based on an intelligent slave station, as an embodiment of this application.

[0055] Figure 2 This is a schematic diagram of the workpiece contour measurement system according to an embodiment of this application;

[0056] Figure 3 This is a general architecture diagram of the workpiece contour measurement system according to an embodiment of this application;

[0057] Figure 4 This is a schematic diagram of the intelligent slave station data processing flow according to an embodiment of this application;

[0058] Figure 5 This is a schematic diagram of a workpiece contour measuring device based on an intelligent slave station, as an embodiment of this application.

[0059] Figure 6 A schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present invention.

[0060] Figure labels: 11, robot; 12, 3D edge finder; 13, workpiece to be measured. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0062] Figure 1 The first aspect of this application is illustrated by an embodiment of the present invention, which provides a workpiece contour measurement method based on an intelligent slave station, applied to a workpiece contour measurement system. The workpiece contour measurement system includes a robot, a 3D edge finder, and an intelligent slave station. The 3D edge finder is installed at the end of the robot, and the intelligent slave station is communicatively connected to both the robot controller and the 3D edge finder. The method includes the following steps:

[0063] S1, construct the measurement direction constraint, roll degree of freedom constraint and preload displacement constraint to obtain the measurement attitude constraint.

[0064] In a specific embodiment, a tool coordinate system is established. and workpiece coordinate system and in the tool coordinate system The displacement trigger direction of the 3D edge finder is defined as the tool axis. ;

[0065] Measurement direction constraints specifically include:

[0066] In response to the availability of the normal n to a local surface region of the workpiece to be measured, the tool axis is set... It remains parallel to the normal n of a local area on the surface of the workpiece to be measured;

[0067] In response to the fact that the normal n of a local surface region of the workpiece to be measured is unavailable, the tool axis is set to... With workpiece coordinate system The Z-direction maintains the first preset included angle setting, and the tool axis Always pointing to the inside of the neighborhood of the workpiece contour being measured;

[0068] Roll freedom constraints specifically include: ensuring the 3D edge finder rotates around the tool axis. Its rotation angle remains constant or changes according to a preset pattern;

[0069] Preload displacement constraint, specifically including: setting preload displacement and safety clearance, in response to determining the distance between the 3D edge finder and the surface of the workpiece along the tool axis. If the distance in the direction is not greater than the preload displacement or the safety clearance, then the measurement is triggered.

[0070] For details, please refer to Figure 2 The workpiece contour measurement system includes a robot 11, a 3D edge finder 12, and an intelligent slave station. The 3D edge finder 12 is mounted at the end of the robot 11 and is used for contact measurement of the contour area of ​​the workpiece 13 to be measured. The workpiece 13 is located within the robot 11's workspace and fixed at the measurement station. The workpiece 13 can be a metal structural component, casting or forging, wheel hub, or other workpiece with a complex contour that is not easily obtained using traditional fixed fixtures or offline measurement methods. The robot 11 can measure the contour of the workpiece 13 in the field environment without complex clamping or repeated reference alignment. During measurement, the six-joint industrial robot 11 controls the 3D edge finder 12 to perform a predetermined scanning motion near the contour of the workpiece 13, causing the edge finder probe to generate multiple triggers on the contour surface, thereby collecting contour surface data.

[0071] In the embodiments of this application, the 3D edge finder 12 is installed after being mounted on the end flange of a six-joint industrial robot, and tool parameter calibration is completed to establish a tool coordinate system {T}. In the tool coordinate system {T}, the trigger sensitivity reverse of the edge finder is defined as the tool axis. That is, the displacement triggering direction. In one embodiment, the Z-axis of the tool coordinate system {T} can be selected as the measurement direction.

[0072] In order to ensure that the comprehensive displacement triggering amount of the 3D edge finder 12 corresponds to the known direction, measurement direction constraints, roll degree of freedom constraints and preload displacement constraints are applied to the end posture of the robot 11 during the scanning process.

[0073] In one embodiment, when the normal n of a local area of ​​the surface of the workpiece to be measured is available, the tool axis is... The tool axis is kept parallel to the normal n of a local surface region of the workpiece under test, so that the trigger displacement is mainly generated along the normal. In another embodiment, when the normal n of a local surface region of the workpiece under test is not available, a combination of a fixed tilt angle and pointing towards the contour region is used, with the tool axis... With workpiece coordinate system The Z-direction maintains the first preset included angle setting, and the tool axis Always point to the inside of the contour neighborhood of the workpiece to be measured and maintain a constant angle to ensure that the measurement direction is consistent throughout the entire scanning segment.

[0074] To ensure that the 3D edge finder 12 can move in the given posture during workpiece contour measurement, the tool axis also needs to be constrained, in addition to satisfying the measurement direction constraints. Its own rotation direction causes the 3D edge finder 12 to rotate around the tool axis The rotation angle remains constant or changes according to a preset pattern to avoid uncontrolled rotation of the 3D edge finder 12 during scanning, which would cause changes in the definition of the measurement direction. In one embodiment, the X-axis of the tool coordinate system {T} is always aligned with the tangential direction t of the contour of the workpiece 13 to be measured, or a fixed second preset angle is maintained, to improve motion smoothness and directional consistency.

[0075] To ensure stable triggering of the 3D edge finder 12 during scanning, a pre-load displacement constraint needs to be constructed. During scan path generation, a pre-load displacement or safety clearance is set between the edge finder and the surface of the workpiece 13. In one embodiment, this pre-load displacement is set along the tool axis. Direction setting preload displacement Alternatively, the 3D edge finder 12 can approach the surface of the workpiece 13 to a safe gap before entering the trigger scanning segment, ensuring that the triggering event can continue to occur during the scanning process.

[0076] S2, acquire the contour curve of the workpiece to be measured, and generate the contour scanning path based on the contour curve and measurement posture constraints.

[0077] In a specific embodiment, the contour curve of the workpiece to be measured is obtained, and a contour scanning path is generated based on the contour curve and measurement posture constraints, specifically including:

[0078] Extract the contour curve of the workpiece from the process model of the workpiece to be tested;

[0079] According to the preload displacement or safety clearance along the tool axis The direction of the offset curve is used to obtain the offset path;

[0080] The offset path is segmented based on the curvature of the contour curve to obtain the segmented offset path.

[0081] Set the desired point density, and based on the curvature of the contour curve and the desired point density, set the scanning speed for each scanning segment of the segmented offset path to obtain the contour scanning path.

[0082] Specifically, for areas with steps, chamfers, or holes on the workpiece 13 to be measured, the offset path can be segmented. Specifically, transition or deceleration sections can be added at points of abrupt curvature change to avoid false triggering or missed triggering caused by sudden changes in attitude and speed. In one embodiment, the scanning segment corresponding to a large curvature area has a reduced speed, while the scanning segment corresponding to a straight line can have a increased speed. In another embodiment, the minimum time interval or minimum spatial interval of the trigger events is planned to ensure that the measurement points on the contour scanning path meet the desired point density requirements, thereby ensuring that the measurement points are continuously distributed on the contour scanning path and avoiding data quality problems caused by excessively sparse or dense distribution.

[0083] S3, continuously scan the workpiece to be measured along the contour scanning path according to the measurement posture constraints, obtain the measurement data distributed along the contour scanning path, and at the same time acquire the pose data of the robot's motion during the continuous scanning process.

[0084] For details, please refer to Figure 3 The robot controller is connected to the multi-axis servo driver via EtherCAT communication. The multi-axis servo driver together constitute the robot's six-joint motion control system, which is used to execute motion control commands during the measurement process. The intelligent slave station is connected to the EtherCAT communication network to acquire the position information of the robot 11 and to send the collected and processed data back to the upper-level industrial controller. The intelligent slave station is also connected to the 3D edge finder 12 via Modbus TCP communication to realize the control of the 3D edge finder 12 and the acquisition of measurement data, thus forming the overall system architecture of robot motion control, data latching and matching, and workpiece contour acquisition.

[0085] After planning and generating the contour scanning path, the robot 11, carrying a 3D edge finder 12 mounted on its end effector, scans the contour of the workpiece 13 to be measured along the generated contour scanning path. During the scanning process, the robot 11 controls the end effector's posture according to pre-planned measurement posture constraints, ensuring that the displacement triggering direction of the 3D edge finder 12 remains consistent throughout the scanning process and corresponds to the expected measurement direction. While maintaining the measurement posture, the robot 11's end effector continuously moves along the contour direction of the workpiece 13 to be measured, causing the edge finder probe to contact the surface of the workpiece 13 and trigger displacement, thereby outputting the corresponding measurement data.

[0086] The scanning process is completed using a continuous scanning method. During the measurement process, the end effector of the robot 11 does not stop at a single point, but moves along the contour scanning path while triggering the measurement to obtain continuous measurement information distributed along the contour of the workpiece 13 to be measured. During the scanning process, the measurement data of the 3D edge finder 12 is acquired synchronously with the pose data of the robot end effector, and is used to generate the corresponding contour measurement data in subsequent steps.

[0087] S4. Obtain the initial time deviation between the intelligent slave station and the 3D edge finder when the workpiece contour measurement system starts, as well as the transmission delay of the measurement data in the communication link between the intelligent slave station and the 3D edge finder. Then, align the pose data and measurement data according to the initial time deviation and transmission delay to obtain aligned pose data and aligned measurement data.

[0088] In a specific embodiment, the initial time deviation between the intelligent slave station and the 3D edge finder when the workpiece contour measurement system starts is obtained, as well as the transmission delay of the measurement data in the communication link between the intelligent slave station and the 3D edge finder. The pose data and measurement data are then time-aligned based on the initial time deviation and transmission delay to obtain aligned pose data and aligned measurement data. Specifically, this includes:

[0089] Obtain the system clock of the intelligent slave station and the local clock of the 3D edge finder. Calculate the initial time deviation between the intelligent slave station and the 3D edge finder when the workpiece contour measurement system starts, based on the system clock of the intelligent slave station and the local clock of the 3D edge finder, as shown in the following formula:

[0090] ;

[0091] in, Indicates the initial time deviation. This indicates the system clock of the intelligent slave station. This indicates the local clock of the 3D edge finder;

[0092] During the initialization phase of the workpiece contour measurement system, the local transmission and reception times of the communication data between the intelligent slave station and the 3D edge finder, recorded based on the local time reference, are acquired. The transmission delay of the measurement data in the communication link between the intelligent slave station and the 3D edge finder is calculated based on the local transmission time, local reception time, and initial time deviation, as shown in the following formula:

[0093] ;

[0094] in, Indicates transmission delay. Indicates the local reception time. Indicates the local transmission time;

[0095] The timestamp corresponding to each pose data and measurement data is determined based on the transmission delay and initial time deviation.

[0096] All pose data and measurement data are time-aligned based on the timestamps to obtain aligned pose data and aligned measurement data.

[0097] Specifically, clock errors exist between different devices, primarily stemming from initial time deviations during system startup and data propagation delays in the communication link. If these clock errors are not addressed during measurement, it becomes difficult to establish an accurate time correspondence between the 3D edge finder 12's measurement data and the robot 11's pose data, thus affecting the spatial positioning accuracy of the measurement points.

[0098] Therefore, during the initialization phase of the workpiece contour measurement system, it is necessary to calculate and compensate for the clock errors between different devices to achieve consistency in time reference between devices, thus providing a foundation for the subsequent matching and alignment of pose data and measurement data.

[0099] The workpiece contour measurement method based on intelligent slave station proposed in this application can calculate the initial time deviation between devices during the initialization stage of the workpiece contour measurement system by using the time relationship between local sending time, local receiving time, initial time deviation and transmission delay. In the subsequent data matching and alignment process, the transmission delay in the communication process is uniformly processed, thereby achieving the effect of time alignment between different devices and ensuring that the reference time of robot pose data and 3D edge finder measurement data is consistent when the measurement trigger event occurs.

[0100] During the workpiece contour scanning process, the intelligent slave station acts as a data intermediary node between the robot 11 and the 3D edge finder 12, responsible for the synchronous acquisition and latching of measurement data and robot pose data. Specifically, such as... Figure 4As shown, the intelligent slave station includes an EtherCAT communication layer and an EtherCAT slave application layer. The EtherCAT communication layer receives and sends EtherCAT messages, enabling real-time communication with the robot controller. The EtherCAT slave application layer includes an EtherCAT data monitoring module and a Modbus TCP communication module, used to obtain the pose data of the robot 11 during operation from the EtherCAT messages and receive sensor measurement data output by the 3D edge finder 12. When acquiring the measurement data from the 3D edge finder 12 and the pose data of the robot 11, the corresponding acquisition time is synchronously latched based on a local time reference.

[0101] This application introduces an intelligent slave station to calculate the clock error and transmission delay between different devices. This enables the intelligent slave station to bind the measurement data and robot pose data under the same time reference during the workpiece contour measurement process, forming a time-consistent and spatially corresponding measurement data unit. This avoids data mismatch problems caused by communication transmission delay or device clock differences, and provides a reliable data foundation for the subsequent comprehensive processing of contour measurement data.

[0102] S5. Spatial mapping is performed on the aligned pose data and the aligned measurement data to obtain the contour measurement data.

[0103] In a specific embodiment, the aligned pose data and the aligned measurement data are spatially mapped to obtain contour measurement data, specifically including:

[0104] Establish the transformation relationship between the robot coordinate system and the edge finder measurement coordinate system, and transform the aligned pose data to the edge finder measurement coordinate system according to the transformation relationship to obtain the tool pose data of the 3D edge finder;

[0105] The measurement direction is determined based on the measurement posture constraints, and the contour measurement data is calculated along the measurement direction based on the tool pose data and the aligned measurement data.

[0106] Specifically, the workpiece contour measurement method based on an intelligent slave station proposed in this application enables the intelligent slave station to achieve synchronous alignment and matching of measurement data and pose data during the continuous movement of the robot 11 by using a unified time reference, thereby generating contour measurement data corresponding to the spatial position. (Reference) Figure 4After establishing a unified time reference, the intelligent slave station synchronously acquires, latches, and matches the robot pose data and the 3D edge finder measurement data. According to the intelligent slave station's data processing flow, firstly, the intelligent slave station synchronizes its device clock to establish a unified time reference for subsequent time alignment of position and measurement data. Secondly, the intelligent slave station monitors and acquires the pose parameters generated during robot movement in real time via the EtherCAT communication interface, and simultaneously acquires the 3D edge finder measurement data via the Modbus TCP communication interface. Then, the intelligent slave station synchronously latches the acquired pose and measurement data, recording and storing the corresponding acquisition time based on the unified time reference. After synchronous latching, it matches the robot pose data and the 3D edge finder measurement data based on the same timestamp, generating corresponding contour measurement data. Finally, the generated contour measurement data is output to the robot controller or host system via the EtherCAT communication interface.

[0107] Based on the generated contour measurement data, the contour reconstruction, dimensional analysis, or quality assessment of the workpiece 13 can be further realized, as well as subsequent processing corrections, assembly verification, or quality inspection. The workpiece contour measurement method based on intelligent slave station proposed in this application can improve the automation level and system integration level of the workpiece contour measurement process without changing the existing robot control architecture and sensors, and has good engineering applicability.

[0108] In a specific embodiment, the method further includes: removing abnormal data from the contour measurement data. The measurement points corresponding to the abnormal data include measurement points that have not been effectively triggered, measurement points that exceed the preset range, measurement points with abnormally abrupt changes in the spacing between adjacent points, and measurement points that are inconsistent with the robot's motion state.

[0109] Specifically, after the synchronous acquisition, latching, and matching of measurement data and robot pose data during the scanning process are completed, the intelligent slave station or host system obtains contour measurement data distributed along the contour of the workpiece 13 to be measured. The contour measurement data is then processed to remove abnormal or invalid data, resulting in processed contour measurement data to improve the accuracy of contour construction.

[0110] Based on the processed contour measurement data, contour description information of the workpiece 13 to be measured is constructed. In one embodiment, the processed contour measurement data is sorted according to the scanning order, and contour curves are generated by interpolation and fitting. When the workpiece 13 to be measured is a three-dimensional contour or a freeform surface boundary, the processed contour measurement data can be further reconstructed or a discrete contour surface can be generated.

[0111] Once the structure is complete, the contour description information is output as a contour point cloud and contour curve parameters for subsequent applications such as dimensional analysis, quality inspection, assembly verification, or machining control.

[0112] This application proposes a workpiece contour measurement method based on an intelligent slave station. Building upon existing robot and workpiece contour measurement systems, it imposes unified constraints on the robot's motion direction and measurement posture during the measurement process and introduces an intelligent slave station with data acquisition, timing coordination, and data management capabilities. Using the proposed method, measurement data from the 3D edge finder 12 and pose data from the robot 11 are synchronously acquired and coordinated, solving the problem of establishing a correspondence between measurement data and specific spatial positions and measurement directions during continuous contour measurement, thus providing system support for acquiring workpiece contour information.

[0113] The workpiece contour measurement method based on intelligent slave station proposed in this application is applicable to applications such as industrial manufacturing, equipment assembly and quality inspection where workpiece contour dimensions are measured, and is especially suitable for measurement objects with free-form surfaces, irregular contours or workpieces with unfixed mounting postures.

[0114] The steps S1-S5 above do not necessarily represent the order of the steps, but are represented by step symbols. The order of the steps can be adjusted.

[0115] Further reference Figure 5 As an implementation of the methods shown in the above figures, this application provides an embodiment of a workpiece contour measuring device based on an intelligent slave station. This device embodiment is similar to... Figure 1 Corresponding to the method embodiments shown, this device can be specifically applied to various electronic devices.

[0116] This application provides a workpiece contour measurement device based on an intelligent slave station, applied to a workpiece contour measurement system. The workpiece contour measurement system includes a robot, a 3D edge finder, and an intelligent slave station. The 3D edge finder is installed at the end of the robot, and the intelligent slave station is communicatively connected to both the robot controller and the 3D edge finder.

[0117] Measurement attitude constraint construction module 1 is configured to construct measurement direction constraints, roll degree of freedom constraints and preload displacement constraints to obtain measurement attitude constraints;

[0118] The scanning path generation module 2 is configured to acquire the contour curve of the workpiece to be measured and generate a contour scanning path based on the contour curve and measurement posture constraints.

[0119] The scanning module 3 is configured to continuously scan the workpiece to be measured along the contour scanning path according to the measurement posture constraints, obtain measurement data distributed along the contour scanning path, and acquire the pose data of the robot's motion during the continuous scanning process.

[0120] The data alignment module 4 is configured to acquire the initial time deviation between the intelligent slave station and the 3D edge finder when the workpiece contour measurement system is started, as well as the transmission delay of the measurement data in the communication link between the intelligent slave station and the 3D edge finder, and to perform time alignment of the pose data and the measurement data according to the initial time deviation and the transmission delay to obtain the aligned pose data and the aligned measurement data.

[0121] Data mapping module 5 is configured to spatially map the aligned pose data and the aligned measurement data to obtain contour measurement data.

[0122] Figure 6 This is a schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present invention. For example... Figure 6 As shown, the electronic device of this embodiment includes a processor 601 and a memory 602; wherein the memory 602 is used to store computer execution instructions; and the processor 601 is used to execute the computer execution instructions stored in the memory to implement the various steps performed by the electronic device in the above embodiment. For details, please refer to the relevant descriptions in the foregoing method embodiments.

[0123] Alternatively, the memory 602 can be either standalone or integrated with the processor 601.

[0124] When the memory 602 is set up independently, the electronic device also includes a bus 603 for connecting the memory 602 and the processor 601.

[0125] This invention also provides a computer storage medium storing computer execution instructions, which, when executed by processor 601, implement the above method.

[0126] This invention also provides a computer program product, including a computer program that, when executed by a processor 601, implements the above-described method.

[0127] In the embodiments provided by this invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or modules, and may be electrical, mechanical, or other forms.

[0128] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to implement the solution of this embodiment according to actual needs.

[0129] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing unit, or each module can exist physically separately, or two or more modules can be integrated into one unit. The unit composed of the above modules can be implemented in hardware or in the form of hardware plus software functional units.

[0130] The integrated modules described above, implemented as software functional modules, can be stored in a computer-readable storage medium. These software functional modules, stored in a storage medium, include several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor 601 to execute some steps of the methods of the various embodiments of this application.

[0131] It should be understood that the processor 601 described above can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor, or the processor 601 can be any conventional processor 601. The steps of the method disclosed in this invention can be directly manifested as the hardware processor 601 executing the steps, or as a combination of hardware and software modules within the processor 601 executing the steps.

[0132] The memory 602 may include high-speed RAM memory, and may also include non-volatile memory NVM, such as at least one disk storage device, and may also be a USB flash drive, portable hard drive, read-only memory, disk or optical disc, etc.

[0133] Bus 603 can be an Industry Standard Architecture (ISA), a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Bus 603 can be divided into address bus, data bus, control bus, etc. For ease of illustration, the bus 603 in the accompanying drawings of this application is not limited to only one bus 603 or one type of bus 603.

[0134] The aforementioned storage medium can be implemented from any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The storage medium can be any available medium accessible to general-purpose or special-purpose computers.

[0135] An exemplary storage medium is coupled to a processor 601, enabling the processor 601 to read information from and write information to the storage medium. Alternatively, the storage medium can be an integral part of the processor 601. The processor 601 and the storage medium can reside in an application-specific integrated circuit (ASIC). Alternatively, the processor 601 and the storage medium can exist as discrete components in an electronic device or a host device.

[0136] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A smart slave station based workpiece profile measurement method applied to a workpiece profile measurement system, characterized in that, The workpiece contour measurement system includes a robot, a 3D edge finder, and an intelligent slave station. The 3D edge finder is installed at the end of the robot, and the intelligent slave station is communicatively connected to both the robot controller and the 3D edge finder. The method includes the following steps: By constructing measurement direction constraints, roll degree of freedom constraints, and preload displacement constraints, the measurement attitude constraints are obtained. Obtain the contour curve of the workpiece to be measured, and generate a contour scanning path based on the contour curve and the measurement posture constraint; According to the measurement posture constraints, the workpiece to be measured is continuously scanned along the contour scanning path to obtain measurement data distributed along the contour scanning path, and at the same time, the pose data of the robot motion during the continuous scanning process is acquired. The initial time deviation between the intelligent slave station and the 3D edge finder when the workpiece contour measurement system is started is obtained, as well as the transmission delay of the measurement data in the communication link between the intelligent slave station and the 3D edge finder. The pose data and the measurement data are time-aligned according to the initial time deviation and the transmission delay to obtain aligned pose data and aligned measurement data. The aligned pose data and the aligned measurement data are spatially mapped to obtain contour measurement data.

2. The workpiece contour measurement method based on intelligent slave station according to claim 1, characterized in that, Establish tool coordinate system and workpiece coordinate system and define the displacement trigger direction of the 3D feeler in the tool coordinate system as the tool axis ; The measurement direction constraint specifically includes: in response to determining that the normal n of the local region of the surface of the workpiece under test is obtainable, causing the tool shaft to remain parallel with the normal n of the local region of the surface of the workpiece under test; in response to determining that the normal n of the local region of the surface of the workpiece under test is not obtainable, causing the tool axis to be set at a first preset angle to the Z direction of the workpiece coordinate system and the tool axis always to point towards the inside of the neighbourhood of the profile of the workpiece under test; The roll freedom constraint specifically includes: causing the 3D edge finder to rotate around the tool axis. Its rotation angle remains constant or changes according to a preset pattern; The preload displacement constraint specifically includes: setting a preload displacement and a safety clearance, in response to determining the distance between the 3D edge finder and the surface of the workpiece along the tool axis. If the distance in the direction is not greater than the preload displacement or the safety clearance, then the measurement is triggered.

3. The workpiece contour measurement method based on intelligent slave station according to claim 2, characterized in that, The process of acquiring the contour curve of the workpiece to be measured and generating a contour scanning path based on the contour curve and the measurement posture constraints specifically includes: Extract the contour curve of the workpiece from the process model of the workpiece to be tested; According to the preload displacement or safety clearance along the tool axis The direction is used to offset the contour curve to obtain the offset path; The offset path is segmented according to the curvature of the contour curve to obtain the segmented offset path. Set the desired point density, and set the scanning speed for each scanning segment of the segmented offset path according to the curvature of the contour curve and the desired point density to obtain the contour scanning path.

4. The workpiece contour measurement method based on intelligent slave station according to claim 1, characterized in that, The method involves acquiring the initial time deviation between the intelligent slave station and the 3D edge finder when the workpiece contour measurement system starts, as well as the transmission delay of the measurement data in the communication link between the intelligent slave station and the 3D edge finder. Based on the initial time deviation and the transmission delay, the pose data and the measurement data are time-aligned to obtain aligned pose data and aligned measurement data. Specifically, this includes: Obtain the system clock of the intelligent slave station and the local clock of the 3D edge finder. Calculate the initial time deviation between the intelligent slave station and the 3D edge finder when the workpiece contour measurement system starts, based on the system clock of the intelligent slave station and the local clock of the 3D edge finder, as shown in the following formula: ； in, Indicates the initial time deviation. This indicates the system clock of the intelligent slave station. This indicates the local clock of the 3D edge finder; During the initialization phase of the workpiece contour measurement system, the local transmission and reception times of the communication data between the intelligent slave station and the 3D edge finder, recorded based on the local time reference, are obtained. The transmission delay of the measurement data in the communication link between the intelligent slave station and the 3D edge finder is calculated based on the local transmission time, the local reception time, and the initial time deviation, as shown in the following formula: ； in, Indicates transmission delay. Indicates the local reception time. Indicates the local transmission time; The timestamp corresponding to each pose data and measurement data is determined based on the transmission delay and the initial time deviation. All the pose data and measurement data are time-aligned according to the timestamp to obtain aligned pose data and aligned measurement data.

5. The workpiece contour measurement method based on an intelligent slave station according to claim 1, characterized in that, The step of spatially mapping the aligned pose data and the aligned measurement data to obtain contour measurement data specifically includes: Establish the transformation relationship between the robot coordinate system and the edge finder measurement coordinate system, and transform the aligned pose data to the edge finder measurement coordinate system according to the transformation relationship to obtain the tool pose data of the 3D edge finder; The measurement direction is determined based on the measurement posture constraints, and contour measurement data is calculated along the measurement direction based on the tool pose data and the aligned measurement data.

6. The workpiece contour measurement method based on an intelligent slave station according to claim 1, characterized in that, Also includes: Abnormal data in the contour measurement data are removed. The measurement points corresponding to the abnormal data include measurement points that have not been effectively triggered, measurement points that exceed the preset range, measurement points with abnormal abrupt changes in the spacing between adjacent points, and measurement points that are inconsistent with the robot's motion state.

7. A workpiece contour measuring device based on an intelligent slave station, applied to a workpiece contour measuring system, characterized in that, The workpiece contour measurement system includes a robot, a 3D edge finder, and an intelligent slave station. The 3D edge finder is installed at the end of the robot, and the intelligent slave station is communicatively connected to both the robot controller and the 3D edge finder. The device includes: The measurement attitude constraint construction module is configured to construct measurement direction constraints, roll degree of freedom constraints, and preload displacement constraints to obtain measurement attitude constraints. The scanning path generation module is configured to acquire the contour curve of the workpiece to be measured, and generate a contour scanning path based on the contour curve and the measurement posture constraints. The scanning module is configured to continuously scan the workpiece to be measured along the contour scanning path according to the measurement posture constraints, obtain measurement data distributed along the contour scanning path, and simultaneously acquire the pose data of the robot's motion during the continuous scanning process. The data alignment module is configured to acquire the initial time deviation between the intelligent slave station and the 3D edge finder when the workpiece contour measurement system is started, as well as the transmission delay of the measurement data in the communication link between the intelligent slave station and the 3D edge finder, and to perform time alignment of the pose data and the measurement data according to the initial time deviation and the transmission delay to obtain aligned pose data and aligned measurement data. The data mapping module is configured to spatially map the aligned pose data and the aligned measurement data to obtain contour measurement data.

8. An electronic device, characterized in that, include: One or more processors; Memory, used to store one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1-6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1-6.

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