Industrial robotic device with improved tool path generation and method of operating the industrial robotic device according to the improved tool path

Abstract

The present invention discloses an apparatus (1) for performing industrial machining operations on a workpiece (2), the apparatus comprising: an anthropomorphic robot (3) comprising an end effector (10) comprising a 2D laser scanner (13) and a machining tool (12); an RTOS computer (4); and a robot controller (5). The computer (4) provides continuous position data along a scanning path to the robot controller (5) and directly provides a synchronization signal (17) to an input port (16) of the 2D laser scanner (13), thereby commanding the continuous scanning operation of the workpiece (2) to be synchronized with the continuous posture of the end effector (10) to obtain 3D shape information about the workpiece (2). The machining tool (12) is operated when the end effector (10) subsequently moves along a tool path and / or along a combined scanning and tool path. The present invention also discloses an apparatus and method for acquiring the shape of an object arranged at a machining area.

Description

[0001] manual Technical Field

[0002] The present disclosure relates to robotic processing of workpieces, in particular robotic welding. The embodiments disclosed herein relate specifically to industrial robots, in particular robotic welding equipment, and more specifically to an anthropomorphic robot provided with a 2D laser scanner at the end effector. Methods for operating such industrial robots (robotic welding equipment), and devices and methods for acquiring shapes by industrial robots are also disclosed herein.

[0003] In the following, for the sake of brevity, robotic welding will mainly be referred to as an illustrative and non-limiting example of robotic processing. Background Art

[0004] Today, automated or robotic machining operations, especially welding operations, require very accurate knowledge of the 3D trajectory or tool path, particularly the welding path, and require very precise mechanical structures and actuation systems in order to manipulate the machining tool, particularly the welding gun, along the 3D trajectory or tool path with maximum accuracy.

[0005] The tool path may be designed to a sample part, while the actual workpiece may have a slightly different shape.

[0006] Furthermore, the ability to follow the welding path or trajectory accurately is necessary in order to take into account thermal effects, for example on very thin steel layers of critical parts of airspace machine structures; indeed, thermal effects can lead to a change in the initial geometry of the object to be welded. Therefore, considering that an airspace machine component can include several welding paths on the same part, it is very important to carry out a 3D measurement of the shape of the object as accurately as possible before and / or after each welding operation, in order to accurately adjust the welding path each time it is necessary.

[0007] Similar problems arise in the case of multilayer coating of workpieces and in other applications, in which the 3D shape of the workpiece changes slightly after the application of each layer.

[0008] Furthermore, the air space machine components and other workpieces are complex 3D structures, and the associated weld (or tooling in general) trajectories similarly have complex 3D paths.

[0009] A very precise 3D shape can usually be acquired by appropriate use of known 2D laser scanners - so that a very precise 3D path can usually be extracted therefrom.

[0010] Most known 2D laser scanners use the triangulation principle to acquire (by means of a suitable camera) an accurate 2D image of the laser line formed at the intersection of the outer surface of the workpiece and the laser scanning plane (provided, for example, by suitable scanning of the laser beam emitted by a laser projector) at a given mutual position thereof.

[0011] In order to acquire a 3D image of the workpiece shape, the 2D laser scanner must move relative to the part to be scanned (along a scan line trajectory or scan path that provides the third dimension or coordinates of each point of the laser line) while taking continuous 2D images; the 3D shape can then be reconstructed from the 3D point cloud.

[0012] In known arrangements, a conveyor moves the workpiece towards a fixed 2D laser scanner, or conversely, the workpiece is stationary and the 2D laser scanner is supported by a carriage movable along a track and takes successive 2D images at regular time intervals. To account for non-constant mutual speeds and other irregularities in the linear motion, such as acceleration and deceleration phases at the beginning and end of the scanning path, encoders can be used to provide correct synchronization between the continuous laser line acquisition and the continuous mutual position of the workpiece and the scanner over time, i.e., to provide correct information in the third dimension.

[0013] However, the 3D complexity, very unusual small-scale manufacturing and possibly large size of the airspace machine components do not allow for such an arrangement.

[0014] It is known in the art to solve these problems by using an anthropomorphic robotic arm which mounts as an end effector a component including, in addition to a welding gun or other tool, a 2D laser scanner: the 3D shape of the workpiece can be acquired by moving the 2D laser scanner relative to the stationary workpiece, while acquiring continuous 2D images.

[0015] The 2D laser scanner is therefore suitable for observing the welding pool or generally observing the processing area; it therefore allows to have up-to-date information about the shape of the workpiece or relevant parts thereof, as the shape changes, for example due to thermal effects or due to newly applied layers.

[0016] The six degrees of freedom of the robotic anthropomorphic arm can be exploited to obtain linear relative motion between the 2D laser camera and the workpiece along a straight scan path or even more complex scan paths.

[0017] However, the problem of knowing exactly where on the 3D shape each 2D image is taken is more severe, and since there is no conveyor or track system for support, it is not possible to use a linear motion encoder.

[0018] Although a stop-and-go approach can be used to overcome the negative effects of non-constant speed and other irregularities in the motion of the robot arm, this is too slow to be practically implemented in real industrial scenarios.

[0019] Therefore, an improved apparatus including an industrial anthropomorphic robot (specifically a welding robot) and a method for performing robotic machining (specifically robotic welding) that addresses the problem of interpreting changes in workpiece shape during machining operations by efficiently and up-to-dately acquiring accurate 3D scan data would be beneficial and would be welcomed in the art.

[0020] More generally, it would be desirable to provide methods and systems suitable for more efficiently acquiring the accurate shape of large and / or delicate workpieces or other objects. Summary of the invention

[0021] In one aspect, the subject matter disclosed herein relates to an apparatus configured to perform industrial machining operations on a workpiece arranged at a machining area. The apparatus includes an anthropomorphic robot movable in a space at the machining area, a computer, and a robot controller. The anthropomorphic robot includes an end effector, the end effector including a 2D laser scanner and a machining tool capable of performing the machining operation on the workpiece. The 2D laser scanner includes a laser projector, a camera, and an input port. The robot controller is configured to enable the robot to move the end effector along a path, and the machining tool can be selectively operated during the movement. The computer is provided with a real-time operating system and is operatively connected to the robot controller and the input port of the 2D laser scanner. The computer is configured to provide continuous position data along the scanning path to the robot controller, and to directly provide a synchronization signal to the input port of the 2D laser scanner, thereby commanding the continuous scanning operation of the workpiece to be synchronized with the continuous pose of the end effector along the scanning path to obtain 3D shape information about the workpiece. The machining tool is configured to be operated when the end effector subsequently moves along the tool path and / or moves along the scanning path, thereby defining a combined scanning and tool path.

[0022] In another aspect, the subject matter disclosed herein relates to a method for performing an industrial machining operation on a workpiece disposed at a machining area. The method includes the steps of acquiring 3D shape information about the workpiece by operating a computer with a real-time operating system to provide continuous position data along a scan path to a robotic controller and directly providing a synchronization signal to an input port of a 2D laser scanner; and operating the robotic controller to move an end effector along the scan path, thereby performing a continuous scanning operation in synchronization with the continuous pose of the end effector. The method also includes the steps of subsequently operating the robotic controller to move the end effector along a tool path different from the scan path, and operating a machining tool while moving the end effector along the tool path; or operating the machining tool while moving the end effector along the scan path, thereby defining a combined scan and tool path.

[0023] In the above aspects, the arrangement of the camera at the end effector of the anthropomorphic robot advantageously allows the workpiece to remain stationary, although this is not strictly necessary, and advantageously allows the highest resolution in contour or shape data acquisition, and therefore maximum accuracy in the 3D tool path, just matching the robot movement capabilities, i.e., the minimum displacement provided by the robot arm.

[0024] Advantageously, the acquisition synchronization of the three coordinates of the 3D point of the cloud is obtained by using a real-time operating system and a synchronization signal, thereby eliminating the need for external encoders.

[0025] Advantageously, updating of the 3D tool path is easily accomplished during subsequent machining processes on the same workpiece.

[0026] Furthermore, new 3D shape data can also be acquired from the same component during the manufacturing process, for example for quality control.

[0027] On the other hand, the subject matter disclosed herein relates to a device configured to acquire the shape of an object arranged at a processing area. The device includes an anthropomorphic robot movable in space at the processing area, a computer, and a robot controller. The anthropomorphic robot includes an end effector, which includes a 2D laser scanner. The 2D laser scanner includes a laser projector, a camera, and an input port. The robot controller is configured to cause the robot to drive the 2D laser scanner along a scanning path. The computer is provided with a real-time operating system and is operatively connected to the robot controller and the input port of the 2D laser scanner. The computer is configured to provide continuous position data along the scanning path to the robot controller, and directly provide a synchronization signal to the input port of the 2D laser scanner, thereby commanding the continuous scanning operation of the object to be synchronized with the continuous posture of the end effector along the scanning path.

[0028] In another aspect, the subject matter disclosed herein relates to a method for acquiring 3D shape information of an object disposed at a processing area. The method comprises the steps of operating a computer with a real-time operating system to provide continuous position data along a scanning path to a robot controller and directly providing a synchronization signal to an input port of a 2D laser scanner; and comprising the steps of operating the robot controller to move an end effector along the scanning path, thereby performing continuous scanning operations in synchronization with the continuous poses of the end effector. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] A more complete understanding of the disclosed embodiments of the present invention and many of its attendant advantages will be readily obtained by reference to the following detailed description when considered in conjunction with the accompanying drawings, which likewise become better understood, wherein:

[0030] - Figure 1 A schematic diagram showing an implementation scheme of an industrial robot device is shown,

[0031] - Figure 2 Yes and Use Figure 1 A flowchart related to a method for a robotic device to perform a machining operation,

[0032] - Figure 3 Yes and Use Figure 1 A flowchart related to a method for a robot device to obtain a workpiece shape, and

[0033] - Figure 4 Is with improved tool path operation Figure 1 A flowchart associated with a method of a robotic device. DETAILED DESCRIPTION

[0034] According to one aspect, the present subject matter relates to apparatus and methods for improving the generation of tool paths that robotic tools must follow. Specifically, in the embodiments disclosed herein, an industrial anthropomorphic robot is used to perform industrial machining operations, such as welding or coating operations, on a workpiece (such as a mechanical part). The arm of the industrial anthropomorphic robot has joints that allow its end effector, which includes a machining tool, to move in space along a desired tool path. The tool path can be designed onto a sample piece, while the actual workpiece may have a slightly different shape, and therefore the desired tool path may also be slightly different. In addition, each operation may include several passes on the same workpiece, and the shape of the workpiece may change from one pass to the next, so that the tool path may also change from one pass to the next.

[0035] In order to acquire the actual shape of the workpiece on which it is necessary to calculate or adjust the tool path, the robot arm is provided with a 2D laser scanner at the end effector. The robot arm takes 2D images of the workpiece at each pose as the workpiece moves into successive poses to provide a third dimension, so that the 3D shape of the workpiece can be reconstructed by the assembly of 2D data from each image paired with its shooting position. The workpiece does not need to move, which is important in several cases. A computer provided with a real-time operating system is used to control the robot arm at least during the scanning movement and to command the taking of images, thereby ensuring by a synchronization signal that each image is taken only after the expected pose has actually been reached, thus ensuring that each point in the 3D point cloud has consistent data, regardless of the movement speed and any irregularities in the movement. Once the shape of the workpiece has been acquired, the tool path for the next machining operation is calculated or adjusted based on the actual shape, which may have changed, for example, due to the thermal effects of a previous welding operation. Because the 2D laser scanner is carried by the same robotic arm end effector that carries the machining tool, the resolution of the reconstructed 3D shape, and therefore the resolution of the tool path defined on that shape, automatically matches the actual ability of the robotic arm to follow that tool path: no computational effort is wasted reconstructing the shape at a higher resolution than when machining will be performed, nor is there a need to interpolate additional positions of the machining tool along a tool path calculated at a lower resolution; therefore, the accuracy is the highest possible.

[0036] During tool operation, additional images may also be captured, again in sync with the successive poses of the robot arm along what becomes a combined scan and tool path.

[0037] According to a more general aspect, the subject matter disclosed herein relates to a system and method for accurately acquiring the shape of an object by a robotic device. The robotic device carries a 2D laser scanner, which is operated as described above by a computer running a real-time operating system. The acquired shape is used for any desired purpose.

[0038] Reference will now be made in detail to embodiments of the present disclosure, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the disclosure rather than limitation of the disclosure. Rather, the scope of the invention is defined by the following claims.

[0039] Figure 1A first embodiment of an apparatus 1 for performing an industrial machining operation (particularly welding) on ​​a workpiece is schematically shown, showing an exemplary workpiece 2, the apparatus 1 comprising an anthropomorphic robot 3 movable in space, a computer 4 and a robot controller 5, which are operatively connected as described in detail below. A platform 6 supporting the workpiece 2 and defining a machining area 7 is also shown, but this is not strictly necessary. The workpiece 2 may, for example, comprise a very thin steel layer of a critical part of a turbomachine. It should be understood that although the controller 5 has been shown as being separate from the robot 3, it may also be included therein, for example in a base 8.

[0040] For reasons that will become clear below, the computer 4 is provided with a real-time operating system (RTOS) 41 .

[0041] The robot 3 comprises in a known manner a base 8 and an arm 9 extending from and rotationally coupled to the base 8, the end of the arm remote from the base 8 being called a hand or end effector 10. Several joints 11 are provided along the arm 9, four joints being shown by way of example.

[0042] The end effector 10 is provided with a processing tool 12, in particular a welding gun. When the processing tool 12 is a welding gun, it can provide heat to the molten metal so as to provide the desired welding of the workpiece 2, such as welding of two metal parts thereof; in other cases, the processing tool can perform the desired processing operation on the workpiece 2, such as spraying paint for coating, spraying glue for gluing, etc.

[0043] The end effector 10 is also provided with a 2D laser scanner 13. The 2D laser scanner 13 comprises, in a known manner, a laser projector 14 and a camera 15 which are angled with respect to each other.

[0044] The 2D laser scanner 13 comprises an input port 16 for receiving a synchronization signal for controlling the laser projector 14 to generate a laser line and the camera 15 to acquire a continuous image. The signal provided at the input port 16 of the 2D laser scanner 13 can be considered as a non-periodic signal comprising pulses, each pulse triggering an image acquisition. It should be noted that the input port 16 is usually available on a 2D laser scanner, however, it is designed to receive a synchronization signal from an encoder operatively connected to a conveyor belt or similar member, which is usually arranged to move the workpiece relative to the 2D laser scanner, when the latter is stationary or operatively connected to a carriage moving on a track to move the 2D laser scanner relative to a stationary workpiece, as described above.

[0045] While in previously known robotic devices the input port of the 2D laser scanner would be connected to an encoder, in device 1 the input port 16 of the 2D laser scanner 13 is instead connected to the computer 4 and receives signals from the computer along a synchronization signal connection 17 .

[0046] A data connection 18 is provided between the 2D laser scanner and the controller 5 to allow the controller 5 to receive the acquired images. The 2D laser scanner 13 may include a pre-processor for the images. The controller 5 may also include an image processing device and / or a memory device for buffering or storing the images (for simplicity, Figure 1 Alternatively, the controller 5 may simply forward the image to be processed elsewhere, such as to the computer 4 or to another remote computer. Alternatively, the received acquired image (possibly pre-processed) may be sent directly from the 2D laser scanner 13 to the computer 4 or remote computer along a suitable data connection (not shown).

[0047] Further data and signal connections 19, 20 are provided between the robot controller 5 and the robot 3. Although generally shown to / from the robot 3, the data and signals carried on connection 19 are primarily intended for controlling the pose of its arm 9; connection 20 primarily carries feedback signals as to whether a pose has been achieved.

[0048] More specifically, when the robot controller 5 typically includes computer program modules (software, hardware or firmware) implementing a path generator 21 and a path actuator 22, data and signal connections 19, 20 are provided between the robot path actuator 22 and the robot 3. In this case, an additional signal connection 23 is provided from the path generator 21 to the path actuator 22. It should be understood from the following description that the path generator 21 is an optional component in this context.

[0049] Additional data and signal connections 24, 25 are provided between the robot controller 5 and the computer 4. More specifically, when the robot controller 5 comprises a path generator 21 and a path actuator 22, data and signal connections 24, 25 are provided between the computer 4 and the path actuator 22. The data and signals carried on the connection 24 are mainly used to control the pose of the robot 3, in particular the pose of its arm 9, as described below; the connection 25 mainly carries feedback signals as to whether the pose has been achieved.

[0050] A gun control line 26 is provided from the controller 5 (specifically, from the path actuator 22) to the end effector 10 for signals for driving the tool 12, e.g., its switching on and off, its power level in the case of a welding gun, and / or other variables. Alternatively, the processing tool 12 may be controlled directly by the computer 4 along a suitable connection (not shown).

[0051] The robot device 1 operates as follows, and allows the method described below to be implemented.

[0052] In a method 100 for welding or performing other machining operations, such as Figure 2 As shown in the flowchart and as continued in reference Figure 1 As discussed, the robot controller 5 together with the computer 4 moves the robot 3 along a defined tool trajectory or tool path or welding path (step 101), and during this movement, appropriately drives the spray gun or other processing tool 12 (step 102). The tool path is the path that the robot 3 (particularly the end effector 10) should follow during the operation of the processing tool 12.

[0053] In more detail, the robot controller 5 and in particular its path effector 22 controls the position of the joints 11 of the robot arm 9 via suitable actuators (not shown) so that the end effector 10 as a whole is provided with a maximum of six degrees of freedom of movement in the space including and surrounding the processing area 7. The signal output by the path effector 22 can be represented as a time-varying signal (but not necessarily a time-continuous signal), wherein each value of the overall signal comprises a plurality of values ​​in robot internal coordinates, such as in the case of six degrees of freedom, Q(t)=[q1(t),q2(t),…q6(t)]. Each quantity qi(tn) represents, for example, the angle that a particular joint 11 of the arm 9 must assume at a particular time tn, so that Q(tn) represents the pose of the end effector 10 at time tn, and the variation of the pose over time Q(t) represents the path followed by the end effector 10. It should be noted that here and hereinafter, italic symbols are used for indexing.

[0054] The path that the end effector 10 must follow is provided to a path effector 22 of the robot controller 5 in another system of spatial coordinates (usually in Cartesian coordinates, such as P(t)=[x(t), y(t), z(t)]), the task of which is to perform the task of spatial transformation. Any other suitable spatial reference system may be used instead of Cartesian coordinates.

[0055] As previously mentioned, the path generator 21 is typically present in the robot controller 5, which may have the task of generating the path P(t) according to the desired machining operation, the shape of the workpiece, its variation relative to the sample piece, the speed of the tool and other variables. In addition, as will be apparent from the following description, the path P(t) may also be generated according to variations in the shape of the workpiece due to, for example, thermal effects and / or other consequences of the machining process being performed. The path generator 21 will generate the path P(t), especially when the scan data from the 2D laser scanner 13 is processed by the robot controller 5.

[0056] Alternatively, the latter task of generating the machining or tool path P(t) in Cartesian space may be performed by the computer 4, particularly when the scan data from the 2D laser scanner 13 is processed by the controller 4 or by an external computer, or when the path generator 21 is absent.

[0057] The complete tool path P(t) can be provided simultaneously and converted into a tool path Q(t) (it should be noted that both P(t) and Q(t) are referred to as tool paths because they are different representations of the same entity), but preferably, in step 103, the robot controller 5, in particular the path generator 21, or the computer 4 outputs the next pose P(tn+1) along the tool trajectory or path in an external reference system, and in step 104, the robot controller 5, in particular the path actuator 22, converts the pose into the robot reference system Q(tn+1) and moves the end actuator 10 to the pose.

[0058] Unless the desired tool trajectory has been completed, as checked in step 105, the above steps are then repeated for the next pose, as indicated by the increment of index n in step 106. It will be appreciated that methods of controlling the repetition of steps other than those illustrated in steps 105, 106 may be equally used. It will also be appreciated that if the controls as schematically shown are used routinely, it may be desirable to add additional "false" start points or "false" end points to the trajectory to ensure that machining is performed along the entire desired trajectory.

[0059] In reference Figure 3 Flowchart and reference Figure 1 In the method 200 for acquiring the shape of the workpiece 2, the computer 4 running the RTOS 41 (in short, the RTOS computer 4 hereinafter) has the task of generating (in addition to the tool path P(t) as described above, it is also possible to generate) a scanning path R(t) in Cartesian coordinates or other spatial reference systems, which is similarly transformed into the robot coordinate system by the path actuator 22, for example, into a scanning path S(t) = [s1(t), s2(t), ...s6(t)]. It should be noted that both R(t) and S(t) are called scanning paths because they are different representations of the same entity, namely the path that the robot 3 (in particular the end effector 10) should follow during the operation of the 2D laser scanner 13.

[0060] Specifically, in step 201, the end effector 10 is in a current pose R(tn) along the scan trajectory R(t). This may be ensured by the computer 4 due to the RTOS 41 and / or possibly by feedback along the connections 20 and 25. Thereafter, in step 202, the RTOS computer 4 outputs the next pose R(tn+1) along the scan trajectory R(t) in the external coordinate system. In step 203, the pose R(tn+1) is transformed into the robot coordinate system by the path effector 22 of the robot controller 5, for example as S(tn+1)=[s1(tn+1), s2(tn+1), ...s6(tn+1)], and the end effector 10 is moved to this new pose.

[0061] As the end effector 10 moves along the scanning path R(t), continuous 2D images are captured by the 2D laser scanner 13 .

[0062] Specifically, in step 204 , the RTOS computer 4 controls the synchronization signal via the connection 17 , in particular changes its state very quickly to generate a trigger pulse, which is output in step 202 no later than the output of the next posture R(tn+1).

[0063] Based on the synchronization signal, in particular when the 2D laser scanner 13 receives such pulses of the synchronization signal at its input port 16, the 2D laser scanner 13 captures a 2D image in step 205. Due to the synchronization signal, it is ensured that the image is captured at the current pose R(tn) which is equivalent to S(tn).

[0064] In more detail, the laser projector 14 emits a laser beam which is suitably scanned (or shaped by suitable optics) in a laser plane to form a scan line extending in a first direction after it intersects the outer surface of the workpiece 2. The camera 15 captures the light reflected by the surface of the workpiece 2, and by the well-known triangulation principle, the distance of each surface point located on the scan line is calculated by the 2D laser scanner 13 itself or by downstream components, in particular the robot controller 5 or computer 4, or even by an external computer. The calculated distances, the position of the laser spot along the scan line and the position of the scan plane (which in turn is indicated by the position of the end effector 10 along the scan path R (t)) provide a 3D point of the shape of the workpiece 2, which is collected at step 206.

[0065] Steps 201 and 202 are shown as separate subsequent steps, and it will be appreciated that step 202 occurs immediately after step 201, preferably as quickly as possible after step 201, in order to speed up the 3D shape acquisition method 200. Step 202 may even be performed strictly simultaneously with step 201: in fact, the time taken to execute step 205, and therefore the time taken to capture an image at the current pose R(tn), is typically shorter than the time taken by the path actuator 22 of the controller 5 to make the transition and start actuating to move from the current pose to the next pose, and therefore, even if the computer 4 issues its two commands (to the controller and the 2D laser scanner) simultaneously, it will still ensure that an image is captured at the current pose R(tn) equivalent to S(tn).

[0066] Unless the desired scan trajectory has been completed, as checked in step 207, the above steps are then repeated for the next pose, as indicated by the increment n of the counter in step 208. It will be appreciated that methods of controlling the repetition of steps other than those illustrated in steps 207, 208 may equally be used. It will also be appreciated that if the controls as schematically shown are used normally, no image will be taken at the last pose, so an additional "false" endpoint should be added to the trajectory.

[0067] The RTOS 41 running on the computer 4 and the synchronization signals emitted thereby ensure that each 2D image is taken at step 205 only after the desired pose has actually been reached and therefore ensures that each point of the 3D point cloud collected at step 205 has consistent data, regardless of the movement speed of the robot 3 and any irregularities in this movement. The perfect synchronization of steps 201 and 205 is schematically shown by the double arrow 209.

[0068] It should be noted that the end effector movement during shape acquisition need not be a translation along a direction orthogonal to the laser plane emitted by the laser projector 14; instead, for example, a rotation of the laser plane may be used. It should be noted that robotic movement can in principle also be used to form the length of the scan line from the laser spot, thereby avoiding the scanning mechanism or any optics of the laser projector; however, the scan trajectory R(t) then becomes quite complex, for example a serpentine pattern.

[0069] It should be emphasized that, in the case where the computer 4 provides the tool trajectory P(t), during the machining operation (see Figure 2 ), the RTOS 41 may also be used to drive the processing tool 12 according to the movement rather than constantly during the entire movement process, for example, to reduce the power provided to the welding gun during deceleration and increase the power during acceleration, so as to obtain an overall constant heat output.

[0070] refer to Figure 4Flowchart and previously discussed Figure 2 and Figure 3 , discloses an improved tool path operation according to Figure 1 Method 300 of a robotic device.

[0071] In optional step 301 , a nominal tool path P(t) is retrieved, for example from a storage device.

[0072] Then, in step 302, the device is operated to obtain information about the actual shape of the workpiece 2 at the processing area 7. Figure 3 The method 200 described in the flowchart is executed, thereby ensuring the highest time correspondence between the posture of the robot 3 and the contour data acquired by the 2D laser scanner 13 through the synchronization signal, so that each collected 3D point has highly consistent data, and ultimately through a complete scanning operation, the workpiece 2 is actually reconstructed by a program executed in the controller 5 or on the computer 4 (or in an external computer).

[0073] The path generator 21 of the controller 5 or computer 4 is then used in step 303 to calculate a tool path P(t), in particular a welding path, or to adjust a nominal or other currently valid tool path according to the workpiece shape obtained in step 302 .

[0074] Then, the machining operation is performed on the workpiece 2 along the tool path P(t) calculated in step 303. Figure 2 The method 100 is performed as described in the flowchart.

[0075] Unless all the required machining operations have been completed for the same workpiece 2, as checked in step 305, a return is made to step 302 to obtain the latest information about the actual shape of the workpiece 2 at the machining area 7 before the subsequent machining operation in step 304. It should be understood that methods of controlling the repetition of steps other than the method illustrated in step 305 may be equally used.

[0076] The advantages of this method 300 of operating a robotic apparatus are appreciated taking into account that the nominal tool path obtained in optional step 301 may have been designed onto a sample part, whereas the actual workpiece 2 may have a slightly different shape.

[0077] Furthermore, the same workpiece 2 is often subjected to multiple subsequent operations, such as welding operations along corresponding multiple welding paths, for example because the workpiece 2 has a complex mechanical structure comprising multiple components. It is highly desirable to check the geometry of the workpiece 2 after each welding operation in order to accurately adjust the subsequent welding paths, taking into account, for example, thermal expansion caused by previous welding paths.

[0078] As another exemplary case, multiple passes may be required to perform a coating operation on the workpiece 2. Each layer slightly increases the workpiece 2, thereby changing its shape and the coating path required during the coating of subsequent layers.

[0079] In each individual operation, a very precise tool path is provided to the machining tool 12. Since the 2D laser scanner 13 is carried by the same robot arm end effector 10 that carries the machining tool 12, the resolution of the reconstructed 3D shape obtained in step 302 and therefore of the tool path defined on this shape in step 303 automatically matches the actual ability of the robot arm 9 to follow this tool path in step 304: no computational effort is wasted in reconstructing the shape at a higher resolution than when machining will be performed, nor is it necessary to interpolate additional positions of the machining tool 12 along the tool path calculated at a lower resolution; therefore, the accuracy is the highest possible, as is the computational efficiency.

[0080] It will be appreciated that the computer 4 simulates a real encoder - thus embodying what is referred to herein as a "simulated encoder" - to generate a signal suitable for use at the input port 16 of the 2D laser scanner 13, which input port is generally referred to as the encoder port.

[0081] In summary, advantageously, real-time updates of the 3D path resulting from subsequent welding or other machining processes are provided, as well as the highest possible resolution of the 3D weld or tool path, based on robot movement and external control capabilities.

[0082] Maximum accuracy in contour data acquisition is achieved via the synchronization signal.

[0083] The tool trajectory is further slightly adjusted "on-line" in accordance with feedback provided by the processing tool 12 using automatic voltage control (AVC) in a manner known per se.

[0084] Additionally or in principle even alternatively, for example, when the tool path is a straight line, the machining operation can be performed along the same tool path as the scanning path while acquiring the 3D shape of the workpiece. In other words, instead of performing step 302 while moving the end effector 10 on a complete scanning path covering the entire surface of the workpiece 2, and then moving the end effector 10 on the complete tool path performing the machining operation, a single movement of the end effector 10 along the combined tool and scanning path can be used to actually perform the machining operation and simultaneously scan the workpiece 2 in order to acquire at least partial data about its shape. The acquired shape can be used to adjust the tool path of the next machining operation, and / or can be slightly adjusted locally.

[0085] The computer 4 may be a personal computer or any suitable computing device operating with any suitable real-time operating system.

[0086] Although an industrial robot device, in particular a robot welding device, has been shown and mentioned above, the device may also be a robot device lacking any processing tools and intended only to acquire the shape of a workpiece or object. In such a case, the robot head 10 will support a 2D laser scanner 13, but a welding gun or other tool 12 will not be present.

[0087] It should be understood that although the shape of the workpiece is mentioned above, this term should not be understood in a limiting manner, because in fact the shape acquired by the robotic device 1 is the shape of the outer surface of the workpiece 2 that is exposed rather than the portion facing the platform 6 or other supporting device (including the base plate), or even the shape of a smaller area of ​​the outer surface of the workpiece 2, which is, for example, of concern in the current machining operation.

[0088] Different interchangeable machining tools 12 may be provided.

[0089] The data and / or signal connections between the components may be wired connections or wireless connections.

[0090] There may be an additional camera at the end effector.

[0091] It is possible that local updating of a portion of a tool path (or combined path) may be performed during the same machining process: as discussed, known automatic voltage control (AVC) may additionally be provided for slightly adjusting the tool trajectory or path (or combined path) during a machining operation.

[0092] Although various aspects of the present invention have been described in terms of various specific embodiments, it is apparent to those of ordinary skill in the art that a variety of modifications, variations, and omissions are possible without departing from the spirit and scope of the present claims. In addition, unless otherwise specified herein, the order or sequence of any process or method steps may be changed or reordered according to an alternative embodiment. References to "one embodiment" or "embodiment" or "some embodiments" throughout this specification are intended to mean that the specific features, structures, or characteristics described in conjunction with the embodiments are included in at least one embodiment of the disclosed subject matter. Therefore, the phrases "in one embodiment" or "in an embodiment" or "in some embodiments" that appear in multiple places throughout the specification do not necessarily refer to the same embodiment. In addition, in one or more embodiments, specific features, structures, or characteristics may be combined in any suitable manner.

[0093] When introducing elements of various embodiments, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0094] The term "operate" when used in expressions such as "operate a computer," "operate a processing tool," and "operate a controller" does not necessarily refer to a person per se, but rather encompasses associated components following a sequence of instructions that may be stored therein and / or imparted by another component in order to perform the methods and steps described herein and protected by the claims.

[0095] When used in connection with the exchange of signals and data between two components, the term "directly" is intended to indicate that there are no additional signal processing components or data processing components in between, but encompasses the presence of components that do not process signals or data in between, such as, for example, wired cables and connectors.

Claims

1. A device (1) configured to perform an industrial machining operation on a workpiece (2) arranged at a machining area (7), the device (1) comprising a humanoid robot (3) capable of moving in space at the machining area (7), a computer (4) and a robot controller (5), The humanoid robot (3) comprises an end effector (10), wherein the end effector comprises a 2D laser scanner (13) and a processing tool (12) capable of performing the processing operation on the workpiece (2), The 2D laser scanner (13) comprises a laser projector (14), a camera (15) and an input port (16), and wherein the robot controller (5) is configured to cause the humanoid robot (3) to move the end effector (10) along a path, the processing tool (12) being selectively operable during the movement, Features The computer (4) is provided with a real-time operating system (RTOS) (41) and is operatively connected to the robot controller (5) and the input port (16) of the 2D laser scanner (13), and is configured to provide continuous position data along the scanning path to the robot controller (5), wherein the position data includes an expected pose of the humanoid robot (3), wherein the computer (4) is configured to directly provide a synchronization signal (17) to the input port (16) of the 2D laser scanner (13) in response to receiving a feedback signal via the connection (25) that the humanoid robot (3) has reached the expected posture, thereby commanding each scanning operation of the continuous scanning operation of the workpiece (2) to be performed only after the end effector reaches each posture of the continuous postures along the scanning path, so as to obtain 3D shape information of the workpiece (2); And in The processing tool (12) is configured to be operated when the end effector (10) is subsequently moved along a tool path and / or along the scan path, thereby defining a combined scan and tool path.

2. The device (1) according to claim 1, wherein the robot controller (5) comprises a path actuator (21) and a path generator (22), and wherein, The computer (4) is configured to provide position data along the scan path and / or the tool path and / or the combined scan and tool path directly to the path executor (21) bypassing the path generator (22).

3. An apparatus (1) according to claim 1 or 2, wherein the computer (4) or the robot controller (5) or another processing device provided in the apparatus (1) is configured to perform a 3D reconstruction of the shape of the workpiece (2) after following a portion of the scanning path and / or the combined scanning and tool path or the entire scanning path and / or the combined scanning and tool path from the scanning data and position data matched by the synchronization signal.

4. The device (1) according to claim 3, wherein the computer (4) or the robot controller (5) or another processing device provided in the device (1) is configured to calculate or adjust the tool path or the combined scan and tool path based on the 3D reconstruction of the shape of the workpiece (2).

5. The device (1) according to claim 1, wherein the synchronization signal comprises a pulse emitted simultaneously with each consecutive position data.

6. The apparatus (1) according to claim 1, wherein the industrial machining operation is welding, the anthropomorphic robot (3) is a welding robot, and the machining tool is a welding gun.

7. The apparatus (1) according to claim 1, wherein the workpiece (2) comprises a very thin steel layer of a critical part of a turbomachinery.

8. A method for performing an industrial machining operation on a workpiece (2) arranged at a machining area (7) by means of an anthropomorphic robot (3) capable of moving in space at the machining area (7), a computer (4) and a robot controller (5), wherein the anthropomorphic robot (3) comprises an end effector (10), the end effector comprising a 2D laser scanner (13) and a machining tool (12) capable of performing the machining operation on the workpiece (2), wherein the 2D laser scanner (13) comprises a laser projector (14), a camera (15) and an input port (16), and wherein the computer (4) is operatively connected to the robot controller (5) and the input port (16) of the 2D laser scanner (13), the method comprising the following steps: (a) obtaining 3D shape information about the workpiece (2) by: (i) operating the computer (4) with a real-time operating system (RTOS) (41) to provide continuous position data along a scan path to the robot controller (5), wherein the position data includes an expected pose of the anthropomorphic robot (3), and in response to receiving a feedback signal via a connection (25) that the anthropomorphic robot (3) has reached the expected pose, directly providing a synchronization signal (17) to the input port (16) of the 2D laser scanner (13); and (ii) operating the robot controller (5) to move the end effector (10) along the scanning path so that each scanning operation of the continuous scanning operation is performed only after the end effector reaches each of the continuous poses along the scanning path, so as to obtain 3D shape information of the workpiece (2); and (b) subsequently operating the robot controller (5) to move the end effector (10) along a tool path different from the scanning path, and operating the processing tool (12) while moving the end effector (10) along the tool path; or operating the processing tool (12) while moving the end effector (10) along the scanning path, thereby defining a combined scanning and tool path.

9. The method according to claim 8, comprising the steps of: After having followed a portion of the scan path or the combined scan and tool path or the complete scan path or the combined scan and tool path from the scan data and position data matched by the synchronization signal, the shape of the workpiece (2) is 3D reconstructed.

10. The method according to claim 9, further comprising the steps of: The tool path and / or the combined scan and tool path is calculated or adjusted based on the 3D reconstruction of the shape of the workpiece (2).

11. The method according to any one of claims 8 to 10, wherein the synchronization signal comprises a pulse emitted simultaneously with each consecutive position data.

12. The method of any one of claims 8 to 10, wherein the industrial machining operation is welding, the humanoid robot is a welding robot, and the machining tool is a welding gun.

13. A method according to any one of claims 8 to 10, wherein the workpiece (2) comprises a very thin steel layer of a critical part of a turbomachinery.

14. A device (1) configured to acquire the shape of a workpiece (2) arranged at a processing area (7), the device (1) comprising an anthropomorphic robot (3) capable of moving in space at the processing area (7), a computer (4) and a robot controller (5), wherein the anthropomorphic robot (3) comprises an end effector (10), the end effector comprising a 2D laser scanner (13), The 2D laser scanner (13) comprises a laser projector (14), a camera (15) and an input port (16), The robot controller (5) is configured to enable the humanoid robot (3) to drive the 2D laser scanner (13) along a scanning path, wherein the computer (4) is provided with a real-time operating system (RTOS) (41) and is operatively connected to the robot controller (5) and the input port (16) of the 2D laser scanner (13), and is configured to provide continuous position data along the scanning path to the robot controller (5), wherein The position data includes the expected position and posture of the anthropomorphic robot (3), and The computer (4) is configured to provide a synchronization signal (17) directly to the input port (16) of the 2D laser scanner (13) in response to receiving a feedback signal via a connection (25) indicating that the humanoid robot (3) has reached the expected posture, thereby commanding each scanning operation of the continuous scanning operation of the workpiece (2) to be performed only after the end actuator reaches each posture of the continuous posture along the scanning path, so as to obtain 3D shape information of the workpiece (2).

15. A method for acquiring 3D shape information of a workpiece (2) arranged at a processing area (7) by means of an anthropomorphic robot (3) capable of moving in a space at the processing area (7), a computer (4) and a robot controller (5), wherein the anthropomorphic robot (3) comprises an end effector (10), the end effector comprises a 2D laser scanner (13), wherein the 2D laser scanner (13) comprises a laser projector (14), a camera (15) and an input port (16), and wherein the computer (4) is operatively connected to the robot controller (5) and the input port (16) of the 2D laser scanner (13), the method comprising the following steps: - operating the computer (4) with a real-time operating system (RTOS) (41) to provide continuous position data along a scanning path to the robot controller (5), wherein the position data includes an expected pose of the anthropomorphic robot (3), and in response to receiving a feedback signal via the connection (25) that the anthropomorphic robot (3) has reached the expected pose, directly providing a synchronization signal (17) to the input port (16) of the 2D laser scanner (13), and -operating the robot controller (5) to move the end effector (10) along the scanning path, thereby performing each scanning operation of the continuous scanning operation only after the end effector reaches each of the continuous postures along the scanning path, so as to obtain 3D shape information of the workpiece (2).

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