Method and system for calibrating a camera by means of a robot arm

Abstract

A method of calibrating a camera (2) with the aid of a robot arm (10) and a calibration reference (3), wherein the camera or the calibration reference is arranged on a distal side segment (12) of the robot arm and the calibration reference or the camera is positionally fixed relative to a proximal side base (11) of the robot arm; comprising the steps of detecting (S10) the calibration reference with the camera in a starting pose of the robot arm; automatically performing (S50) a plurality of search cycles, wherein in each search cycle a different pose is driven to with the robot arm and at least one image of the calibration reference is taken with the camera in this pose, and at least one search cycle is performed based on the starting pose; determining (S60) a transformation between a reference system (K) fixed to the camera and a reference system (R) fixed to the robot arm based on the taken images and the pose of the robot arm at the time of taking the images. The invention also relates to a system or computer program (product).

Description

Technical Field

[0001] The present invention relates to a method and system for calibrating a camera using a robotic arm and a calibration reference, and a computer program or computer program product for performing the method. Summary of the Invention

[0002] The purpose of this invention is to improve camera calibration.

[0003] The object of this invention is achieved by a method for calibrating a camera using a robotic arm. This invention also relates to a system, computer program, or computer program product designed or used to perform the methods described herein.

[0004] According to one embodiment of the invention, in an extended version, a camera is arranged on the distal segment of a robot arm, and a calibration reference is positioned fixed relative to the proximal base of the robot arm.

[0005] According to an alternative embodiment of the invention, in an extended scheme, the calibration reference is instead arranged on the distal segment of the robot arm, while the camera is positioned fixed relative to the proximal base of the robot arm.

[0006] In this manner, by moving the robotic arm (the distal segment), the camera and the calibration reference can be moved relative to each other, thereby causing changes in the image taken by the camera from the calibration reference, or in other words, the image or view of the calibration reference in the camera image, particularly its position, orientation, size, and / or viewing angle. By comparing multiple images taken by the camera from the calibration reference in different poses of the robotic arm, the transformation between a reference system fixed to the camera and a reference system fixed to the robotic arm can be determined in a known manner based on the different camera images (the image or view of the calibration reference in them); in one embodiment, particularly when the camera is positioned on the distal segment of the robotic arm, the transformation between a reference system fixed to the camera and a reference system fixed in position relative to the distal segment; or in another embodiment, particularly when the calibration reference is positioned on the distal segment of the robotic arm, the transformation between a reference system fixed to the camera and a reference system fixed in position relative to the proximal base.

[0007] The distal segment can be, in particular, the tool side or end segment of the robotic arm, and the proximal base can be, in particular, a fixed base or a base fixed to the environment. The distal segment and the proximal base are preferably connected to each other by at least three, in particular at least six joints, or in an extended embodiment, rotary joints.

[0008] In one embodiment, the calibration reference has known, preferably prior-known, features, such as size and / or markings, such as patterns. Preferably, the calibration reference can be constructed as a planar or plate-like structure, which can improve its operation and / or detection.

[0009] In one implementation, the reference system fixed to the camera and / or the reference system fixed to the robot arm mentioned herein are (respectively) coordinate systems, and in an extended embodiment, they are Cartesian coordinate systems.

[0010] According to one embodiment of the present invention, a method for calibrating a camera using a robotic arm and a calibration reference includes the following steps: - Use a camera to detect and calibrate a reference object while the robot arm is in its initial pose.

[0011] In one implementation, the method includes the following steps: - The robot arm moves to the starting posture as follows or under the following conditions: in this starting posture, the calibration reference can be detected by the camera.

[0012] Therefore, in one implementation, the operator can manually control the robotic arm. In an advantageous extension, a reference marker is displayed to the operator in the camera image. The operator can adjust the robotic arm accordingly to align the reference marker with the image of a calibration reference in the camera image. This can improve, in particular simplify, and / or accelerate the journey to a favorable starting pose. Similarly, the journey to the starting pose can be automated, for example, based on the known position of the camera or calibration reference relative to the robotic arm, or based on image-assisted search, etc.

[0013] According to one embodiment of the present invention, the method comprises the following steps: - Multiple search cycles are executed automatically, wherein in each search cycle, a robotic arm moves to another pose and, in that pose, at least one image of a calibration reference is captured using a camera, and one or more of these search cycles are based on a starting pose, determined in one embodiment from the starting pose. In one embodiment, one or more images of the calibration reference have also been captured using a camera while moving to the corresponding (final) pose.

[0014] By automating the execution of search cycles and performing one or more search cycles based on the initial posture during this period, calibration can be advantageously improved compared to manual movement of the robotic arm by an operator, particularly by using a (more) advantageous posture and / or improving speed, reliability and / or accuracy, and / or enabling calibration to be performed (better) by (less) experienced operators.

[0015] According to one embodiment of the present invention, the method includes the following steps: - Based on or using or according to the captured images and the pose of the robot arm when these images were captured, determine, preferably automatically, the transformation between a reference system fixed to the camera and a reference system fixed to the robot arm. In one embodiment, determining the transformation includes initially determining the transformation and updating the transformation determined (so far) one or more times, preferably updating the transformation determined (so far) after one or more search cycles based on one or more images captured in (corresponding) search cycles and (multiple) poses (when) the one or more images were captured.

[0016] Determining such a transformation based on different poses of the robotic arm and images taken from the calibration reference at different positions of the camera and the calibration reference relative to each other using a camera in those poses is known to those skilled in the art as so-called "hand-eye calibration." In one embodiment, calibrating the camera using a robotic arm and a calibration reference includes, in particular, the determination of the transformation.

[0017] In one implementation, at least one image of the calibration reference is captured using a camera in an initial orientation, wherein the transformation between a reference system fixed to the camera and a reference system fixed to the robot arm is determined based on the image and the initial orientation. This can improve calibration, particularly increasing speed, reliability, and / or accuracy.

[0018] In one implementation, based on one or more images captured during the search cycle and / or in the initial pose, one or more camera parameters, preferably camera-specific and / or camera-internal or intrinsic, are determined. These parameters are preferably image capture and / or image processing parameters, such as aperture and / or exposure and / or color and / or scaling parameters, etc., which are specific to the respective camera and / or do not depend on, or depend solely on, its current pose relative to the robotic arm. This allows for more comprehensive and / or faster and / or more accurate calibration, and / or improved camera usage. Accordingly, in addition to determining transformations or corresponding extrinsic parameters, calibration may also include determining camera-specific and / or camera-internal or intrinsic camera parameters.

[0019] In one implementation, before one or more search cycles, preferably between two or more search cycles, (respectively).

[0020] - Based on the images captured so far and the robot arm's pose when these images were captured, determine the transformation between the reference system fixed to the camera and the reference system fixed to the robot arm. In an extended scheme, this transformation is updated, and then...

[0021] - Based on the transformations determined (so far), automatically execute the (corresponding or current) search cycle; and then

[0022] - After performing the (corresponding or current) search cycle, the (determined) transformation is (further) updated (if necessary) based on one or more images taken during that search cycle and the (multiple) poses of the robot arm when those images were taken. This allows for improved calibration, particularly in subsequent search cycles using (more) favorable poses and / or improved speed, reliability, and / or accuracy.

[0023] In one implementation, during one or more search cycles, the vehicle is (each time) driven again from the starting attitude to the desired attitude. This "recentering" can improve calibration, particularly increasing speed, reliability, and / or accuracy.

[0024] It is particularly advantageous to combine this “recentering” with the previously described update-based transformation to determine the desired attitude, as this can improve the convergence of the calibration.

[0025] In one embodiment, the distal segment of the robot arm translates (from) a starting pose along a first straight line set to be fixed relative to a reference system fixed to the robot arm, and in an extended embodiment, along a coordinate axis fixed to a camera or a reference system fixed to the robot arm; then, in an extended embodiment, again translates (from) the starting pose along another straight line set to be fixed relative to the reference system fixed to the robot arm, and in an extended embodiment, along another coordinate axis of the reference system; and then again translates (from) the starting pose along yet another straight line set to be fixed relative to the reference system fixed to the robot arm, and in an extended embodiment, along yet another coordinate axis of the reference system.

[0026] Based on the changes in the images taken by the camera from the calibration reference caused by the translational motion, a preferred initial or initial transformation between the reference system fixed to the camera and the reference system fixed to the robot arm is determined, wherein the (initial or initial) transformation is then updated based on the images taken in a preferred subsequent search cycle and the pose of the robot arm when these images were taken, and / or one or more search cycles are automatically executed based on the transformation.

[0027] Therefore, in one extended scheme, starting from the initial posture, the distal segment with the camera or calibration reference is translated along a first straight line, preferably fixed to the first coordinate axis of the reference system fixed to the camera or the robot; and based on the changes in the image taken by the camera from the calibration reference due to this translational movement, a preferably initial or preliminary transformation between the reference system fixed to the camera and the reference system fixed to the robot arm is determined: if the image of the calibration reference in the camera image does not (again only) move along the first straight line or coordinate axis, the transformation can be determined accordingly, in particular, to make the corresponding straight lines or axes in the reference system fixed to the camera and the reference system fixed to the robot parallel.

[0028] Then, in an extended scheme, starting again from the initial posture, the distal limb is translated along another second straight line, preferably the coordinate axis of the reference system, which is preferably perpendicular to the first straight line or axis, and the transformation is determined based on the change in the image taken by the camera from the calibration reference due to this second translational movement: if the image of the calibration reference in the camera image does not (again only) move along the second straight line or coordinate axis, the transformation can be determined accordingly, in particular, so that the corresponding straight lines or axes in the reference system fixed to the camera and the reference system fixed to the robot are parallel, preferably aligned.

[0029] Then, for another third line, preferably a coordinate axis, the same thing can be repeated, which is preferably perpendicular to the first and second lines or axes.

[0030] These movements allow for the particularly advantageous determination of an initial transformation between a reference system fixed to the camera and a reference system fixed to the robot arm. Based on this initial transformation, a preferred search cycle can then be performed, which is then executed with particular advantage. This allows for improved calibration, particularly with the use of (more)favorable postures and / or increased speed, reliability, and / or accuracy, and / or enables calibration to be performed (better) by (less)inexperienced operators.

[0031] In one implementation, two or more attitudes to be driven are determined such that the camera and calibration reference have different positions and / or orientations relative to each other.

[0032] In a preferred extension, two or more driving postures are determined such that the camera and calibration reference are offset from the starting posture along and / or twisted about the coordinate axes of a reference system fixed to the camera or robot arm. Preferably, during two or more search cycles, the distal segment with the camera or calibration reference is translated or rotated about the different coordinate axes of the reference system (fixed to the camera or robot arm) in directions of translation or rotation. This improves calibration, particularly by using more advantageous postures and / or increases speed, reliability, and / or accuracy, and / or allows calibration to be performed (better) by less experienced operators.

[0033] Additionally or alternatively, in a preferred extension, the two or more attitudes to be navigated to are determined such that, in each subsequent attitude, the camera and calibration reference have a larger, particularly maximum, minimum, or average distance from each other. Preferably, in two or more search cycles, the distance between the camera and calibration reference in the attitude to be navigated to in subsequent search cycles is increased relative to the distance in the earlier search cycle, or the attitude to be navigated to in subsequent search cycles is determined accordingly. In one embodiment, one or more search cycles are performed with a larger, particularly maximum, minimum, or average distance between the camera and calibration reference compared to one or more, preferably immediately preceding, search cycles, or the distance between the camera and calibration reference is increased (respectively or gradually) in two or more successive search cycles. This can improve calibration, particularly by using a more advantageous attitude and / or by improving speed, reliability, and / or accuracy, and / or by enabling calibration to be performed (better) by less experienced operators.

[0034] In one implementation, one or more orientations to be driven toward, which in one extension is during the corresponding search cycle and in another extension is before the execution of the corresponding search cycle, are determined in such a way or under such conditions that a calibration reference (in or under the orientation) is arranged at the boundary of the camera detection area.

[0035] Alternatively or particularly preferably additionally, during one or more movements of the distal segment of the robotic arm, particularly during one or more search cycles, the detection of a calibration reference by a camera is monitored, and the movement is terminated if the calibration reference reaches the boundary of the camera detection area in one embodiment or leaves the camera detection area in another embodiment.

[0036] Particularly advantageously, the two features described above can be combined, particularly in the following manner: In one embodiment, the distal segment of the moving robotic arm is simultaneously monitored for detection of a calibration reference object via a camera; if the calibration reference object reaches the boundary of the camera detection area in one embodiment or leaves the camera detection area in another embodiment, the (corresponding) movement is terminated, and the pose of the calibration reference object at the boundary of the camera detection area is used as the pose in which a corresponding image of the calibration reference object is captured by the camera, the image and the pose being used together to determine the transformation between the reference system fixed to the camera and the reference system fixed to the robotic arm.

[0037] Particularly advantageously, two or more of the above features are combined in one of the following two embodiments.

[0038] First, preferably manually or by an operator, the robot arm is moved or controlled to a starting posture in which the calibration reference can be detected by the camera, and particularly preferably aligned in the camera image by the location and / or relative to the displayed reference mark.

[0039] Then, preferably, an initial transformation between the reference system fixed to the camera and the reference system fixed to the robot arm is determined. This is particularly advantageous for variant B, which is described below, but calibration can also be advantageously (further) improved in variant A.

[0040] To determine the initial transformation, or in determining the initial transformation, the robotic arm preferably moves the distal segment slowly along a first axis of a reference system fixed to the camera or a reference system fixed to the robotic arm, so that the first axis of the reference system fixed to the camera and the first axis of the reference system fixed to the robotic arm are aligned with each other, or in other words, the transformation is determined such that the two first axes are parallel to each other. This operation is then repeated for a second axis perpendicular to the first axis, and, if necessary, for a third axis perpendicular to the first and second axes; in an extended scheme, this is done again from the starting position. For example, if the distal segment with the camera or calibration reference moves along its x-axis or in its x-axis direction in the reference system fixed to the robotic arm, but the calibration reference in the camera image produces movement in the xy direction, then the reference system fixed to the camera twists about the z-axis until only movement in the x-axis direction occurs in the reference system fixed to the camera, or in other words, the transformation is determined accordingly.

[0041] In one variant, A, the robotic arm moves and twists its distal segment to different (towards, to be driven, or final) poses in multiple search cycles, wherein the distance between the calibration reference and the camera gradually increases in successive (towards, to be driven, or final) poses or search cycles. Here, movement continues in a single search cycle until the calibration reference is positioned at or away from the camera detection area, and an image is captured in the pose where the calibration reference is positioned at the detection area boundary, based on which the transformation is updated. The robotic arm then returns to the initial pose and executes the next search cycle. In this way, the search range is used iteratively as large as possible, particularly advantageously using different poses due to the increasing distance. This improves calibration, particularly increasing speed, reliability, convergence, and / or accuracy.

[0042] In variant B, an initial transformation is used between a determined reference system fixed to the camera and a reference system fixed to the robot arm, causing the distal segment to move successively along or in the direction of different coordinate axes of the reference system fixed to the camera or the reference system fixed to the robot arm, and preferably additionally to twist about the corresponding axis. Here, the detection of a calibration reference by the camera can be monitored to prevent the calibration reference from leaving the camera detection area. Again, an image is captured in the driven posture, or in an extended embodiment, one or more additional images are captured while driving to that state; the transformation is updated based on this image or images; and the robot arm is returned to the initial posture and the next search cycle is executed.

[0043] If enough images have been captured or the calibration is sufficiently accurate, the search cycle is terminated. Furthermore, in one implementation, the execution is terminated if the calibration reference leaves the camera detection area or if the robotic arm collides with its environment.

[0044] According to one embodiment of the invention, a system for calibrating a camera by means of a robotic arm and a calibration reference is provided, particularly designed by hardware and / or software techniques, especially programming techniques, to perform the methods described herein.

[0045] In one implementation, the system includes: - Camera; and / or - Robotic arm; and / or - Calibration reference; and / or - A device for detecting and calibrating a reference object using a camera in the initial posture of a robotic arm; and / or - A means for performing multiple search cycles, wherein in each search cycle a robotic arm moves to a different pose and, in that pose, captures at least one image of a calibration reference using a camera, and wherein at least one search cycle is performed based on a starting pose; and / or - A device for determining the transformation between a reference system fixed to a camera and a reference system fixed to the robot arm based on an image captured and the pose of the robot arm when the image was captured.

[0046] The systems and / or apparatuses under the present invention can be constructed using hardware and / or software techniques, and in particular include: at least one processing unit, preferably connected to a storage system and / or a bus system via data or signal connections, particularly a digital processing unit, particularly a microprocessor unit (CPU), graphics card (GPU), etc.; and / or one or more programs or program modules, particularly one or more computers preferably programmed accordingly. The processing unit can be designed to: execute instructions implemented as programs stored in the storage system; acquire input signals from the data bus; and / or send output signals to the data bus. The storage system can have one or more, particularly different, storage media, particularly optical, magnetic, solid-state, and / or other non-volatile media. The program can be designed to embody or execute the methods described herein, enabling the processing unit to perform the steps of these methods, and thereby, in particular, to control camera calibration and / or (for this purpose) control the camera and / or robotic arm. In one embodiment, the computer program product can have, particularly can be, a computer-readable and / or non-volatile storage medium for storing programs or instructions, or a storage medium on which programs or instructions are stored. In one implementation, the program or instructions are executed by a system or controller, particularly a computer or an array of computers, such that the system or controller, particularly one or more computers, performs the methods or one or more steps thereof described herein, or the program or instructions are designed for this purpose.

[0047] In one implementation, one or more, particularly all, steps of the method are implemented entirely or partially by a computer, or one or more, particularly all, steps of the method are executed entirely or partially automatically, particularly by the system or its apparatus. Attached Figure Description

[0048] Further advantages and features of the present invention will be set forth below by way of examples. For this purpose, they will be illustrated in part: Figure 1 A system for calibrating a camera using a robotic arm and a calibration reference is shown according to one embodiment of the present invention.

[0049] Figure 2 The camera image is shown.

[0050] Figure 3 The system is shown in another pose of the robotic arm.

[0051] Figure 4 A variation of the system is shown.

[0052] Figure 5 The method is shown.

[0053] The attached figure label list is as follows: 2: Camera 3: Calibration reference 3': Imaging 10: Robotic Arm 11: Base 12: Distal lateral limb E: Detection area (boundary) K: Coordinate system fixed to the camera M: Reference marker R: Coordinate system fixed to the robot arm X K : x-axis of K Y K : K's y-axis X R : x-axis of R Y R : The y-axis of R. Detailed Implementation

[0054] Figure 1 A system for calibrating a camera 2 using a robotic arm 10 and a calibration reference 3, according to one embodiment of the present invention, is shown.

[0055] In the first step S10 (see Figure 5 In the process, the robotic arm 10 is controlled to an initial posture, under which the imaging 3' of the reference object 3 is calibrated. Figure 2 The camera image from camera 2 is centered relative to the reference marker M. An image was captured in this pose, and based on this image, camera-specific or internal / intrinsic camera parameters can be determined.

[0056] Then, starting from this initial posture, in step S20, the distal segment 12 of the robot arm 10, on which the camera 2 is located, is moved along the x-axis X of the coordinate system or reference system R fixed to the robot arm. R Movement. Here, if the image 3' in the camera image is not only along the x-axis X of the coordinate system or reference system K fixed to the camera. K The movement is not in the direction of the x-axis, but rather, for example, in the direction of the x-axis and simultaneously in the direction of the y-axis of K. KMoving in the direction of the axis determines or updates the transformation between the two systems R and K accordingly. This transformation can be initialized by default as an identity matrix, for example, by rotating about the z-axis so that the x-axis of the two systems R and K are parallel to each other. Similarly, in steps S30 and S40, the y-axis and z-axis are also oriented parallel to each other, thus determining the initial transformation or starting transformation.

[0057] Then a search cycle is executed, in which, in variant A, as the distance between camera 2 and calibration reference 3 increases, camera 2 is moved by robotic arm 10 until the image 3' of calibration reference 3 is located at the edge of the detection area E of camera 2 (see [link to documentation]). Figure 2 In this posture, and in an extended scheme, in an intermediate posture while driving towards the edge, an image of the calibration reference 3 is captured by camera 2. Figure 5 Step S50).

[0058] Then, based on these images and poses, the transformation is updated ( Figure 5 Step S60). If it is determined that the transformation is not accurate enough (S70: "N"), then a new search cycle with a larger distance between camera 2 and calibration reference 3 is executed; otherwise, or if calibration reference 3 leaves the detection area E of camera 2 or the robot arm 10 collides with its environment (S70: "Y" respectively), then the method is terminated. Figure 5 Step S80).

[0059] In another similar variant B, starting from the initial posture, during the corresponding search cycle, the distal limb 12 or the camera 2 is moved to a predetermined posture along the coordinate axis of the coordinate system or reference system R fixed to the robot arm, and twisted around the axis (S50), and the transformation is also updated based on the images captured thereand the posture when these images were captured (S60).

[0060] Figure 4 A variation of the system or method is shown, wherein the calibration reference 3 is hereby arranged, in turn, on the distal end limb 12 of the robot arm 10, while the camera 2 is fixed in position relative to the proximal end base 11 of the robot arm. Here, the method or system is otherwise similar to the aforementioned implementation, as described previously.

[0061] In this disclosure, "having X" generally does not mean exhaustive, but is short for "having at least one X," and also includes "having two or more X" and "having Y in addition to X." Although exemplary embodiments have been set forth in the foregoing description, it should be noted that many variations are possible. Furthermore, it should be noted that these exemplary embodiments are merely examples and should not in any way limit the scope of protection, application, or construction. Rather, the foregoing description provides guidance for those skilled in the art to implement at least one exemplary embodiment, wherein various changes can be made, particularly with respect to the function and arrangement of the components, without departing from the scope of protection given by the claims and their equivalent combinations.

Claims

1. A method for calibrating a camera (2) using a robotic arm (10) and a calibration reference (3), wherein, - The camera is arranged on the distal segment (12) of the robot arm, and the calibration reference is fixed in position relative to the proximal base (11) of the robot arm; or - The calibration reference is arranged on the distal segment (12) of the robot arm, and the camera is fixed in position relative to the proximal base (11) of the robot arm; The method includes the following steps: -The calibration reference is detected by the camera (S10) in the initial posture of the robotic arm; - Automatically execute (S50) multiple search cycles, wherein in each search cycle, the robotic arm moves to a different pose, and at least one image of the calibration reference is captured by the camera in the pose, and at least one search cycle is executed based on the initial pose; and - Based on the captured image and the pose of the robot arm when the image was captured, determine (S60) the transformation between the reference system (K) fixed to the camera and the reference system (R) fixed to the robot arm.

2. The method according to claim 1, characterized in that, At least one image of the calibration reference is captured using the camera in the initial posture, wherein the transformation between the reference system fixed to the camera and the reference system fixed to the robot arm is also determined based on the image and the initial posture (S20, S30, S40).

3. The method according to any one of the preceding claims, characterized in that, At least one camera parameter is determined based on one or more of the captured images.

4. The method according to any one of the preceding claims, characterized in that, - Before at least one of the search cycles, based on the images captured so far and the pose of the robot arm when the images were captured, determine the transformation between the reference system fixed to the camera and the reference system fixed to the robot arm; -Then, the search cycle is automatically executed based on the determined transformation; and - After performing the search cycle, update the transformation based on the attitude of the vehicle during the search cycle and at least one image captured.

5. The method according to any one of the preceding claims, characterized in that, During one or more of the search cycles, the vehicle starts from the initial attitude and heads toward the desired attitude.

6. The method according to any one of the preceding claims, characterized in that, The distal segment of the robotic arm translates from an initial pose along a first straight line set to be fixed relative to a reference system fixed to the robotic arm, and then translates once or multiple times along another straight line set to be fixed relative to the reference system fixed to the robotic arm. A transformation between the reference system fixed to the camera and the reference system fixed to the robotic arm is determined based on changes in images captured by the camera from the calibration reference caused by the translation. This transformation is then updated based on the pose traversed and images captured therein during a search cycle, and / or at least one search cycle is automatically executed based on this transformation.

7. The method according to any one of the preceding claims, characterized in that, At least two orientations to be driven in are determined such that the camera and calibration reference have different positions and / or orientations relative to each other in these orientations, in particular offset and / or twisted about a coordinate axis along a reference system fixed to the camera or a reference system fixed to the robot arm from the initial orientation, and / or the camera and calibration reference have a greater distance in the subsequent orientations to be driven in.

8. The method according to any one of the preceding claims, characterized in that, At least one desired orientation is determined such that the calibration reference is positioned at the boundary of the camera's detection area (E).

9. The method according to any one of the preceding claims, characterized in that, During at least one movement of the distal segment of the robotic arm, particularly during a search cycle, the camera's detection of the calibration reference is monitored, and the movement is terminated if the calibration reference reaches the boundary of the camera's detection area (E) or leaves the camera's detection area.

10. A system for calibrating a camera (2) using a robotic arm (10) and a calibration reference (3), the system being designed to perform the method according to any one of the preceding claims, and / or including: A device for detecting a calibration reference using a camera in the initial posture of the robotic arm, wherein the camera is arranged on the distal segment of the robotic arm and the calibration reference is fixed in position relative to the proximal base of the robotic arm, or the calibration reference is arranged on the distal segment of the robotic arm and the camera is fixed in position relative to the proximal base of the robotic arm. A device for automating multiple search cycles, wherein in each search cycle the robotic arm moves to a different pose, and in said pose at least one image of the calibration reference is captured by the camera, and at least one search cycle is performed based on the initial pose; and A device for determining the transformation between a reference system fixed to a camera and a reference system fixed to the robot arm based on the captured image and the posture of the robot arm when the image was captured.

11. A computer program or computer program product, wherein, The computer program or computer program product includes, in particular, instructions stored on a computer-readable and / or non-volatile storage medium, which, when executed by one or more computers or the system according to claim 10, cause the one or more computers or the system according to claim 10 to perform the method according to any one of claims 1 to 9.

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