Delta robot calibration method, control system, delta robot and robot system

Abstract

A method of calibrating a delta robot (12) includes: performing an arm movement (54) by moving one drive link (32a, 32b, 32c) relative to the other two drive links (32a, 32b, 32c); measuring the movement of a point (50) having a fixed relationship with an inclined body (24) as an arm measurement during the arm movement (54); performing a tilt movement (56) by tilting the inclined body (24) about a fifth axis (44); measuring the movement of the point (50) as a tilt measurement during the tilt movement (56); and calibrating a fourth axis (40) based on a comparison of the arm measurement and the tilt measurement. A method of calibrating the fifth axis (44), a control system (26), and a robot system (10) are also provided.

Description

Technical Field

[0001] The present disclosure generally relates to the calibration of a delta robot. In particular, a method of calibrating a delta robot including five axes, a control system for calibrating such a delta robot, a delta robot including such a control system, and a robot system and a measuring device including such a delta robot are provided. Background Art

[0002] Industrial robots based on the concept of parallel kinematic robots are previously known. Such robots are mainly used for picking up and placing relatively small objects. A delta robot is a parallel robot. For example, delta robots are used in the food industry, in the field of surgery and medical science, in the pharmaceutical industry and in many other fields. For example, delta robots are used to transfer chocolate bars or similar objects from a moving conveyor belt to a predetermined location, such as into a packaging box, at high speed and with high precision.

[0003] One known way to calibrate a delta robot is to partially disassemble the delta robot by separating the driven connection from the driving connection and locking the driving connection in a defined position by means of a fixing device. However, as the design of delta robots becomes more and more complex and bulky, disassembling a delta robot for calibration tends to be cumbersome, cumbersome and time consuming. The above type of disassembly is also not possible for some delta robots due to different designs. Furthermore, if the delta robot comprises more than three axes, the additional axes also need to be calibrated.

[0004] WO 2014029448 A1 discloses a fixture for calibrating a delta robot. The fixture fixes the longitudinal axes of a transmission arm to be parallel. With this configuration, the fixture always fixes the transmission arm at the same reference angle regardless of the length of the transmission arm. Summary of the invention

[0005] It is an object of the present disclosure to provide a simple method of calibrating a delta robot.

[0006] Yet another object of the present disclosure is to provide a less time consuming method of calibrating a delta robot.

[0007] Yet another object of the present disclosure is to provide an accurate method of calibrating a delta robot.

[0008] It is yet another object of the present disclosure to provide a method of calibrating a delta robot that addresses several or all of the aforementioned objects in combination.

[0009] Yet another object of the present disclosure is to provide a control system for calibrating a delta robot, which solves one, several or all of the aforementioned objects.

[0010] Yet another object of the present disclosure is to provide a delta robot including a control system, which solves one, several or all of the aforementioned objects.

[0011] Yet another object of the present disclosure is to provide a robot system comprising a delta robot and a measuring device, which solves one, several or all of the aforementioned objects.

[0012] According to one aspect, a method for calibrating a delta robot is provided, the delta robot comprising: a base; a translation body; three parallel robotic arms connected between the base and the translation body, each robotic arm comprising a driving connection and a driven connection, and the robotic arms are arranged to translate the translation body on three axes; a rotating body, arranged to rotate around a fourth axis relative to the translation body; and a tilting body, connected to the rotating body and arranged to tilt around a fifth axis relative to the rotating body; wherein the method comprises: performing arm movement by moving one of the driving connections relative to the other two driving connections; measuring the movement of a point having a fixed relationship with the tilting body during the arm movement as an arm measurement value; performing a tilt movement by tilting the tilting body around the fifth axis; measuring the movement of a point during the tilt movement as a tilt measurement value; and calibrating the fourth axis based on a comparison of the arm measurement value and the tilt measurement value.

[0013] The drive links of the manipulator arms provide the first three axes of the delta robot. Each drive link may be independently driven by an actuator, such as an electric motor. Each manipulator arm may include a driven link or a pair of driven links between the drive link and the translational body. The driven link may be connected to each of the translational body and the associated drive link via a ball joint.

[0014] The delta robot may further include a telescopic rotating shaft for controlling the rotating body to rotate about a fourth axis and a telescopic tilting shaft for controlling the tilting body to tilt about a fifth axis.

[0015] During arm movement, the fourth and fifth axes can be locked.During tilt movement, the first three axes and the fourth axis can be locked.

[0016] If the fourth axis could be perfectly calibrated, the tilt measurement at that point would be the expected value related to the arm measurement at that point, e.g., the projection of the arm movement in the projection plane would be parallel to the projection of the tilt movement in the projection plane. However, positioning errors may occur in a delta robot due to kinematic errors and / or incomplete calibration. An error in the fourth axis will manifest itself as an angular deviation between the arm movement and the tilt movement that is greater than expected (e.g., non-zero). By exploiting this deviation in a five-axis delta robot, the method enables simple and accurate calibration of the fourth axis by finding the parallelism (or any other arbitrarily defined relationship) between one of the drive links and the tilt body.

[0017] According to one variant, the method comprises calibrating the fourth axis based on a value indicating parallelism between the arm measurements and the inclination measurements.

[0018] The arm measurements and tilt measurements can be made with the aid of a measuring device according to the present disclosure, such as a laser measuring device. The measuring device can measure the absolute or relative movement of the arm movement and the tilt movement. In any case, the measurements can be made in an arbitrary coordinate system.

[0019] The method may further include performing the movement of the delta robot after calibrating the fourth axis.

[0020] The method may also include: commanding the positioning of the tilting body before the tilting movement so that the fifth axis is parallel to the axis of one of the drive connections (i.e., one of the first three axes). If there is an error in the fourth axis, the fifth axis will not be positioned completely parallel to one of the axes of the drive connection. However, the error will then be calibrated by the method. The command can optionally be completed before the arm moves. In this case, the comparison can include determining the parallelism (e.g., the deviation in parallelism) between the relatively moving drive connection and the fifth axis. As an alternative, the method may also include: commanding the positioning of the tilting body so that the fifth axis adopts any definable relationship (i.e., not necessarily parallel) to the axis of one of the drive connections.

[0021] The point having a fixed relationship to the tilt body may be the tool center point (TCP).However, alternative points may be used, such as a reference mark on a visible area of ​​the tilt body or a reference mark on an end effector attached to the tilt body.

[0022] The arm movement may include moving one of the drive connections while keeping the other two drive connections stationary. Alternatively, the arm movement may include simultaneously moving the first drive connection and the second drive connection while keeping the third drive connection stationary. And in this way, one drive connection (the third drive connection) will move relative to the other two drive connections (the first drive connection and the second drive connection).

[0023] The arm measurement may include the movement of the measured point as a projection in the projection plane, and the tilt measurement may include the movement of the measured point as a projection in the projection plane. By measuring the movement of the point in the projection plane, the calibration error of the fourth axis may be determined as the angle between the two lines corresponding to the projection plane. Therefore, a simpler measuring device may be used, such as a camera or other two-dimensional measuring device. The projection plane may be substantially perpendicular to or perpendicular to the fourth axis. In this case, each projection of the arm movement and the tilt movement of the point will be a straight line or substantially a straight line.

[0024] As an alternative, the arm measurement value may include determining a plane in which the point moves during arm movement as the arm movement plane, determining a plane in which the point moves during tilt movement as the tilt movement plane, and calibrating the fourth axis based on a comparison of the arm movement plane and the tilt movement plane. For example, the difference between the normals of each of the arm movement plane and the tilt movement plane may be determined, and the calibration of the fourth axis may be performed based on the difference.

[0025] According to another aspect, a method for calibrating a delta robot is provided, the delta robot comprising: a base; a translation body; three parallel robotic arms connected between the base and the translation body, each robotic arm comprising a driving connection and a driven connection, and the robotic arms are arranged to translate the translation body on three axes; a rotating body, arranged to rotate around a fourth axis relative to the translation body; and an inclined body, connected to the rotating body and arranged to tilt around a fifth axis relative to the rotating body; wherein the method comprises: measuring the position of an inclined body plane having a fixed relationship with the inclined body as a first plane measurement value in a first position of the inclined body; rotating the rotating body around the fourth axis so that the inclined body moves from the first position to a second position; measuring the position of the inclined body plane in the second position of the inclined body as a second plane measurement value; and calibrating the fifth axis based on a comparison of the first plane measurement value and the second plane measurement value.

[0026] If the fifth axis would be perfectly calibrated, the first plane measurement would be the expected value related to the second plane measurement, for example, the inclined body plane in the first plane measurement would be parallel to the inclined body plane in the second measurement. In this case, the inclined body plane will not wobble at all during the rotation of the rotating body around the fourth axis. However, positioning errors may occur in the delta robot due to motion errors and / or incomplete calibration. The error in the fifth axis will be manifested as an angular deviation between the first plane measurement and the second plane measurement that exceeds expectations (e.g., non-zero). Therefore, when the rotating body rotates around the fourth axis, the inclined body plane will wobble slightly and / or represent an imperfect cone. By utilizing this deviation in a five-axis delta robot, the method achieves a simple and accurate calibration of the fifth axis by finding the parallelism (or any other arbitrarily defined relationship) between the inclined body plane in the first plane measurement and the inclined body plane in the second plane measurement.

[0027] The tilting body plane may be constituted by a mounting flange or other flat surface of the tilting body, for example. The angular distance that the rotating body rotates about the fourth axis so that the tilting body moves from the first position to the second position may be arbitrary, such as 180 degrees.

[0028] According to a variant, only the rotating body is moved in order to move the tilting body from the first position to the second position. That is, during the movement of the tilting body from the first position to the second position, the first three axes and the fifth axis can be locked.

[0029] According to one variant, the method comprises calibrating the fifth axis based on a value indicative of parallelism between the first planar measurement and the second planar measurement.

[0030] The first plane measurement and the second plane measurement can be performed with the aid of a measuring device according to the present disclosure, such as a laser measuring device. The measuring device can measure the absolute position or relative position of the inclined body plane in the corresponding first position and second position of the inclined body. In any case, the measurement of the relative position of the inclined body plane can be performed in any coordinate system.

[0031] The method may further include performing the movement of the delta robot after calibrating the fifth axis.

[0032] The method may also include commanding the tilt body to be positioned in a zero position before the first plane measurement, wherein the tilt body plane is positioned in the zero position perpendicular to the fourth axis. If there is an error in the fifth axis, the tilt body plane will not be positioned completely perpendicular to the fourth axis. However, the error will then be calibrated by the method.

[0033] The method may further include determining an angular difference between a plane of the inclined body in the first position and a plane of the inclined body in the second position, and calibrating the fifth axis based on the angular difference.

[0034] The calibration may also be based on an angular distance about the fourth axis of the rotation body that causes the tilting body to move from the first position to the second position.

[0035] According to another aspect, a control system for calibrating a delta robot is provided, the delta robot comprising: a base; a translation body; three parallel robotic arms connected between the base and the translation body, each robotic arm comprising a driving connection and a driven connection, and the robotic arms are arranged to translate the translation body on three axes; a rotating body, arranged to rotate about a fourth axis relative to the translation body; and a tilting body, connected to the rotating body and arranged to tilt about a fifth axis relative to the rotating body; wherein the control system comprises a data processing device and a memory having a computer program stored thereon, the computer program comprising program code, which, when executed by the data processing device, causes the data processing device to perform the following steps: commanding an arm movement by moving one of the driving connections relative to the other two driving connections; commanding measurement of movement of a point having a fixed relationship with the tilting body as an arm measurement value during the arm movement; commanding a tilt movement by tilting the tilting body about a fifth axis; commanding measurement of movement of a point during the tilt movement as a tilt measurement value; and calibrating the fourth axis based on a comparison of the arm measurement value and the tilt measurement value. The computer program may also include program codes which, when executed by a data processing device, cause the data processing device to perform or instruct the data processing device to perform any steps according to the present disclosure.

[0036] According to another aspect, a control system for calibrating a delta robot is provided, the delta robot comprising: a base; a translation body; three parallel mechanical arms connected between the base and the translation body; the mechanical arms are arranged to translate the translation body on three axes; a rotating body arranged to rotate about a fourth axis relative to the translation body; and a tilting body connected to the rotating body and arranged to tilt about a fifth axis relative to the rotating body; wherein the control system comprises a data processing device and a memory having a computer program stored thereon, the computer program comprising program code, when executed by the data processing device, the program code causes the data processing device to perform the following steps: command measurement of a tilting body plane having a fixed relationship with the tilting body as a first plane measurement value in a first position of the tilting body; command rotation of the rotating body about the fourth axis so that the tilting body moves from the first position to the second position; command measurement of the tilting body plane in the second position of the tilting body as a second plane measurement value; and calibrate the fifth axis based on a comparison of the first plane measurement value and the second plane measurement value. The computer program may also include program code, when executed by the data processing device, the program code causes the data processing device to perform or command the execution of any step according to the present disclosure.

[0037] According to another aspect, a delta robot is adopted, comprising: a base; a translation body; three parallel robotic arms connected between the base and the translation body, each robotic arm comprising a driving connection and a driven connection, and the robotic arms are arranged to translate the translation body on three axes; a rotating body, arranged to rotate around a fourth axis relative to the translation body; a tilting body, connected to the rotating body and arranged to tilt around a fifth axis relative to the rotating body; and a control system according to the present disclosure.

[0038] According to yet another aspect, there is provided a robotic system comprising a delta robot according to the present disclosure and a measuring device configured to measure movement of a point having a fixed relationship to an inclined body and / or configured to measure an inclined body plane having a fixed relationship to the inclined body. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Other details, advantages and aspects of the present disclosure will become apparent from the following embodiments taken in conjunction with the accompanying drawings, in which:

[0040] Figure 1 : A perspective view schematically showing a robot system including a delta robot and a measuring device;

[0041] Figure 2 : schematically shows a bottom view of the delta robot in a starting position;

[0042] Figure 3 : schematically shows a bottom view of the delta robot after the actuator arm moves;

[0043] Figure 4 : schematically shows a bottom view of the delta robot after performing a tilt movement;

[0044] Figure 5 : schematically shows a bottom view of the delta robot with the tilting body in a first position; and

[0045] Figure 6 : Schematically shows a bottom view of the delta robot with the tilting body in the second position. DETAILED DESCRIPTION

[0046] In the following, a method of calibrating a delta robot comprising five axes, a control system for calibrating such a delta robot, a delta robot comprising such a control system, and a robot system and a measuring device comprising such a delta robot will be described. The same reference numerals will be used to denote the same or similar structural features.

[0047] Figure 1 Schematically shown is a perspective view of a robot system 10 comprising a delta robot 12 and a measuring device 14. The delta robot 12 comprises a base 16, a translation body 18, three parallel robot arms 20a, 20b, 20c, a rotation body 22 and a tilting body 24. Figure 1 A Cartesian coordinate system X, Y, Z is also shown for reference purposes.

[0048] The delta robot 12 also includes a control system 26. The control system 26 controls the operation of the delta robot 12. In this example, the control system 26 also controls the operation of the measurement device 14. The control system 26 includes a data processing device 28 and a memory 30. A computer program is stored in the memory 30. The computer program includes program code that, when executed by the data processing device 28, causes the data processing device 28 to perform or command the performance of any of the steps described herein.

[0049] exist Figure 1 In the example of FIG. 1 , each robot arm 20a, 20b, 20c comprises a driving connection 32a, 32b, 32c and a pair of driven connections 34a, 34b, 34c. Each driven connection 34a, 34b, 34c is connected to each of the associated driving connections 32a, 32b, 32c and the translation body 18 via a ball joint (not shown). Here, the driven connections 34a, 34b, 34c are composed of rigid rods.

[0050] The delta robot 12 also includes three actuators 36a, 36b, 36c for independently driving the corresponding drive connection 32a, 32b, 32c. In this example, each actuator 36a, 36b, 36c is an electric motor. The first actuator 36a is arranged to drive the first drive connection 32a to rotate around the first axis 38a. The second actuator 36b is arranged to drive the second drive connection 32b to rotate around the second axis 38b. The third actuator 36c is arranged to drive the third drive connection 32c to rotate around the third axis 38c. Each driven connection 34a, 34b, 34c follows the movement of the associated drive connection 32a, 32b, 32c, thereby causing the movement of the translation body 18.

[0051] The delta robot 12 is a parallel robot. The manipulators 20a, 20b, 20c form a plurality of kinematic chains connecting the base 16 and the translation body 18. The manipulators 20a, 20b, 20c restrict the movement of the translation body 18 to pure translation, that is, movement only in the X, Y or Z direction without rotation.

[0052] The rotating body 22 is rotationally coupled to the translating body 18. In this example, the rotating body 22 is arranged inside the translating body 18. The rotating body 22 can rotate relative to the translating body 18 around the fourth axis 40. Figure 1 As shown, the delta robot 12 of this example includes a telescopic rotation shaft 42 for controlling the rotation of the rotating body 22 relative to the translation body 18 around the fourth axis 40 .

[0053] The tilting body 24 is rotatably coupled to the rotating body 22. The tilting body 24 can be tilted relative to the rotating body 22 around the fifth axis 44. Figure 1 As shown, the delta robot 12 of this example includes a telescopic tilting shaft 46 for controlling the tilting body 24 to tilt relative to the rotating body 22 about the fifth axis 44. The tilting body 24 of this example has a bracket shape.

[0054] The delta robot 12 further comprises an end effector 48. Here, the end effector 48 is illustrated as a suction gripper having a generally flat surface. The end effector 48 is rigidly attached to the tilting body 24.

[0055] exist Figure 1 , point 50 is indicated on the end effector 48. Point 50 is used for calibration of the delta robot 12, as will be described below. In this example, point 50 is constituted by the tool center point of the end effector 48. However, a point 50 alternatively positioned in a fixed relationship relative to the tilt body 24 may also be used.

[0056] Figure 1Also shown is an inclined body plane 52 of the inclined body 24. The inclined body plane 52 is used for calibration of the delta robot 12, as will be described below. In this example, the inclined body plane 52 is aligned with the flat surface of the end effector 48. However, an inclined body plane 52 alternatively positioned in a fixed relationship relative to the inclined body 24 may also be used.

[0057] The measuring device 14 is arranged to measure the movement of the point 50. The measuring device 14 is also arranged to measure the position of the tilting body plane 52. In this example, the measuring device 14 is a laser measuring device configured to measure the absolute movement of the point 50 and the absolute position of the tilting body plane 52.

[0058] Figure 2 A bottom view of the delta robot 12 in a starting position is schematically shown. A method of calibrating the fourth axis 40 will now be described.

[0059] In this example, by rotating the rotating body 22 about the fourth axis 40, first the fifth axis 44 is commanded to be positioned parallel to the second axis 38b. The arm movement is then performed by moving the second drive connection 32b. In this example of arm movement, the first drive connection 32a and the third drive connection 32c are stationary, the rotating body 22 is locked from rotating about the fourth axis 40, and the tilting body 24 is locked from rotating about the fifth axis 44. During the arm movement, relative movement occurs between the second drive connection 32b and the first drive connection 32a and the third drive connection 32c.

[0060] Figure 3 Schematically shows a bottom view of the delta robot 12 after performing the arm movement 54. After the arm movement 54, the point 50 in fixed relationship with the tilt body 24 has moved from Figure 2 Move the starting position in Figure 3 The position in Figure 3 . The projection of the arm movement 54 in the XY plane is linear, but the arm movement 54 is not linear in space. In this example, the arm movement 54 is slightly curved in a plane parallel to the YZ plane. The linear projection of the arm movement 54 in the XY plane is detected by the measurement device 14 and recorded by the control system 26 as an arm measurement value.

[0061] In this example, the delta robot 12 is then returned to the Figure 2 The tilting movement is then performed by tilting the tilting body 24 about the fifth axis 44. In this example of a tilting movement, each of the three drive connections 32a, 32b, 32c is stationary and the rotating body 22 is locked from rotating about the fourth axis 40.

[0062] Figure 4 Schematically, a bottom view of the delta robot 12 is shown after performing a tilting movement 56. Figure 4 As shown, a point 50 having a fixed relationship with the tilt body 24 is located in the XY plane from Figure 2 The starting position in the linear movement to Figure 4 The linear projection of the tilt movement 56 is detected by the measuring device 14 and recorded as a tilt measurement by the control system 26. However, the tilt movement 56 in space is not linear.

[0063] If the fourth axis 40 is well calibrated, the linear projections of the arm movement 54 and the tilt movement 56 in the XY plane will be parallel. However, if the fourth axis 40 is incorrectly calibrated, the linear projections of the arm movement 54 and the tilt movement 56 in the XY plane will not be parallel. The angle between the linear projections is then calculated, and the fourth axis 40 is recalibrated based on this angle.

[0064] As an alternative to using linear projections, the arm measurements may include determining the plane in which the point 50 moves during the arm movement 54 as the arm movement plane, determining the plane in which the point 50 moves during the tilt movement 56 as the tilt movement plane, and calibrating the fourth axis 40 based on a comparison of the arm movement plane and the tilt movement plane. For example, the difference between the normals of each of the arm movement plane and the tilt movement plane may be determined, and calibration of the fourth axis 40 may be performed based on the difference.

[0065] Figure 5 Schematically represented is a bottom view of the delta robot 12 when the tilting body 24 has adopted the first position 58. The method of calibrating the fifth axis 44 will now be described.

[0066] In this example, the tilt body 24 is commanded to be positioned in the zero position as the first position 58. In the zero position, the tilt body plane 52 is positioned perpendicular to the fourth axis 40 if the fifth axis 44 is well aligned.

[0067] The position of the tilting body plane 52 in the first position 58 of the tilting body 24 is then measured by the measuring device 14. The first position 58 of the tilting body plane 52 is recorded as a first plane measurement value by the control system 26. The rotating body 22 is then rotated about the fourth axis 40. By this rotation, the tilting body 24 moves from the first position 58 to the second position.

[0068] Figure 6 The bottom view of the delta robot 12 is schematically shown with the tilting body 24 in the second position 60. In this example, the rotating body 22 is rotated about the fourth axis 40. Figure 5 The first position in 58 and Figure 6During this rotation, the three drive connections 32a, 32b, 32c are stationary and the tilting body 24 is locked from rotating about the fifth axis 44.

[0069] The second position 60 of the tilt body plane 52 is recorded by the control system 26 as the second plane measurement. If the fifth axis 24 is well calibrated, the tilt body plane 52 in the first position 58 of the tilt body 24 will be parallel to the tilt body plane 52 in the second position 60 of the tilt body 24. However, if the fifth axis 44 is incorrectly calibrated, the first plane measurement and the second plane measurement will not be parallel. In this case, the tilt body plane 52 will swing as the tilt body 24 rotates around the fourth axis 40. The angle between the tilt body plane 52 according to the first plane measurement and the tilt body plane 52 according to the second plane measurement is then calculated. The fifth axis 44 is then recalibrated based on this angle and optionally also based on the angular distance that the rotating body 22 rotates around the fourth axis 40 between the first position 58 and the second position 60.

[0070] Although the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the present invention is not limited to what has been described above.For example, it is to be understood that the dimensions of the components may be varied as desired.

Claims

1. A method of calibrating a delta robot (12), the delta robot (12) comprising: Base (16); Translation body (18); three parallel mechanical arms (20a, 20b, 20c) connected between the base (16) and the translation body (18), each mechanical arm (20a, 20b, 20c) comprising a driving connection (32a, 32b, 32c) and a driven connection (34a, 34b, 34c), and the mechanical arms (20a, 20b, 20c) are arranged to translate the translation body (18) on three axes (X, Y, Z); A rotating body (22) arranged to rotate relative to the translating body (18) around a fourth axis (40); as well as a tilting body (24) connected to the rotating body (22) and arranged to tilt relative to the rotating body (22) about a fifth axis (44); The method comprises: Actuating arm movement (54) by moving one of the drive links (32a, 32b, 32c) relative to the other two drive links (32a, 32b, 32c); During movement of the arm (54), measuring movement of a point (50) in fixed relationship to the tilting body (24) as an arm measurement; performing a tilting movement (56) by tilting the tilting body (24) about the fifth axis (44); During the tilting movement (56), measuring the movement of the point (50) as a tilt measurement; and The fourth axis (40) is calibrated based on a comparison of the arm measurements and the tilt measurements.

2. The method according to claim 1, further comprising: The positioning of the tilting body (24) is commanded so that, before the tilting movement (56), the fifth axis (44) is parallel to the axis (38a, 38b, 38c) of one of the drive connections (32a, 32b, 32c).

3. A method according to claim 1 or 2, wherein the point (50) is a tool centre point.

4. A method according to any of the preceding claims 1-2, wherein the arm movement (54) comprises moving one of the drive connections (32a, 32b, 32c) while keeping the other two drive connections (32a, 32b, 32c) stationary.

5. A method according to any one of the preceding claims 1-2, wherein the arm measurement comprises measuring the movement of the point (50) as a projection in a plane (XY), and wherein the tilt measurement comprises measuring the movement of the point (50) as a projection in the plane (XY).

6. A method of calibrating a delta robot (12), the delta robot (12) comprising: Base (16); Translation body (18); three parallel mechanical arms (20a, 20b, 20c) connected between the base (16) and the translation body (18), each mechanical arm (20a, 20b, 20c) comprising a driving connection (32a, 32b, 32c) and a driven connection (34a, 34b, 34c), and the mechanical arms (20a, 20b, 20c) are arranged to translate the translation body (18) on three axes (X, Y, Z); A rotating body (22) arranged to rotate relative to the translating body (18) around a fourth axis (40); as well as a tilting body (24) connected to the rotating body (22) and arranged to tilt relative to the rotating body (22) about a fifth axis (44); The method comprises: measuring the position of an inclined body plane (52) having a fixed relationship with the inclined body (24) as a first plane measurement value in a first position (58) of the inclined body (24); Rotating the rotating body (22) around the fourth axis (40) so that the tilting body (24) moves from the first position (58) to a second position (60); measuring the position of the inclined body plane (52) in the second position (60) of the inclined body (24) as a second plane measurement value; as well as The fifth axis (44) is calibrated based on a comparison of the first plane measurements and the second plane measurements.

7. The method according to claim 6, further comprising: Positioning the tilt body (24) in a zero position is commanded prior to the first plane measurement, wherein the tilt body plane (52) is positioned in the zero position perpendicular to the fourth axis (40).

8. The method according to claim 6 or 7, further comprising: An angular difference between the inclined body plane (52) in the first position (58) and the inclined body plane (52) in the second position (60) is determined, and the fifth axis (44) is calibrated based on the angular difference.

9. The method according to any one of claims 6 to 7, wherein the calibration is also based on an angular distance around the fourth axis (40) of the rotating body (22), which angular distance causes the tilting body (24) to move from the first position (58) to the second position (60).

10. A control system (26) for calibrating a delta robot (12), the delta robot (12) comprising: A base (16); a translation body (18); three parallel mechanical arms (20a, 20b, 20c) connected between the base (16) and the translation body (18), each mechanical arm (20a, 20b, 20c) comprising a driving connection (32a, 32b, 32c) and a driven connection (34a, 34b, 34c), and the mechanical arms (20a, 20b, 20c) are arranged to translate the translation body (18) on three axes (X, Y, Z); a rotating body (22) is arranged to for the translational body (18) to rotate about a fourth axis (40); and a tilting body (24) connected to the rotating body (22) and arranged to tilt about a fifth axis (44) relative to the rotating body (22); wherein the control system (26) comprises a data processing device (28) and a memory (30) having a computer program stored thereon, the computer program comprising program code which, when executed by the data processing device (28), causes the data processing device (28) to perform the steps of: commanding the actuator arm to move (54) by moving one of the drive links (32a, 32b, 32c) relative to the other two drive links (32a, 32b, 32c); commanding measurement of movement of a point (50) in fixed relation to the tilting body (24) as an arm measurement during movement (54) of the arm; commanding a tilting movement (56) by tilting the tilting body (24) about the fifth axis (44); During said tilting movement (56), commanding measurement of the movement of said point (50) as a tilt measurement; as well as The fourth axis (40) is calibrated based on a comparison of the arm measurements and the tilt measurements.

11. A control system (26) for calibrating a delta robot (12), the delta robot (12) comprising: A base (16); a translation body (18); three parallel mechanical arms (20a, 20b, 20c) connected between the base (16) and the translation body (18); the mechanical arms (20a, 20b, 20c) are arranged to translate the translation body (18) on three axes (X, Y, Z); a rotating body (22) arranged to rotate around a fourth axis (40) relative to the translation body (18); and a tilting body (24) connected to the rotating body (22) and arranged to tilt around a fifth axis (44) relative to the rotating body (22); wherein the control system (26) includes a data processing device (28) and a memory (30) having a computer program stored thereon, the computer program including program code, which, when executed by the data processing device (28), causes the data processing device (28) to perform the steps of: commanding measurement of an inclined body plane (52) having a fixed relationship with the inclined body (24) as a first plane measurement value in a first position (58) of the inclined body (24); commanding the rotating body (22) to rotate about the fourth axis (40) so that the tilting body (24) moves from the first position (58) to a second position (60); commanding measurement of the inclined body plane (52) in the second position (60) of the inclined body (24) as a second plane measurement value; as well as The fifth axis (44) is calibrated based on a comparison of the first plane measurements and the second plane measurements.

12. A delta robot (12), comprising: Base (16); Translation body (18); three parallel mechanical arms (20a, 20b, 20c) connected between the base (16) and the translation body (18), each mechanical arm (20a, 20b, 20c) comprising a driving connection (32a, 32b, 32c) and a driven connection (34a, 34b, 34c), and the mechanical arms (20a, 20b, 20c) are arranged to translate the translation body (18) on three axes (X, Y, Z); A rotating body (22) arranged to rotate relative to the translating body (18) around a fourth axis (40); an inclined body (24) connected to the rotating body (22) and arranged to be inclined about a fifth axis (44) relative to the rotating body (22); and A control system (26) according to claim 10 or 11.

13. A robot system (10) comprising a delta robot (12) according to claim 12 and a measuring device (14), the measuring device (14) being configured to measure the movement of a point (50) having a fixed relationship with the tilting body (24) and / or being configured to measure an tilting body plane (52) having a fixed relationship with the tilting body (24).

14. The robotic system (10) according to claim 13, wherein the measuring device (14) is a laser measuring device.

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