TCP calibration method, device and equipment of robot tool and medium

Abstract

The invention relates to a TCP calibration method, device, equipment and medium for a robot tool, and the method comprises the steps: setting a measurement plane formed by the intersection of a first light ray and a second light ray, determining the intersection point position of the tool and the measurement plane according to the light ray on-off time during the circle drawing motion of the tool during TCP calibration, the direction information of the tool and the position information of the initial intersection point in the flange coordinate system are further determined, the tip rising length from the initial intersection point to the tip point of the tool is determined according to the light on-off time when the tool moves up and down, and the tip rising length is further determined according to the direction information of the tool, the position information of the initial intersection point in the flange coordinate system and the tip rising length. And determining a TCP calibration result of the tool. According to the technical scheme, during TCP calibration, only the light on-off time data collected by the sensor is adopted, dependence on data of all axes of a robot or specific shape information of a tool is not needed, the repeated precision of a calculation result is high, and the whole calibration process is automatic.

Description

Technical Field

[0001] The present disclosure relates to the field of robot technology, and in particular, to a TCP calibration method, device, equipment and medium for a robot tool. Background Art

[0002] Robots are increasingly applied to various daily scenarios. The tool is installed on the end flange of the robot and is used to perform various tasks. In order to ensure the working accuracy of the robot, it is necessary to calibrate the TCP (Tool CenterPoint) of the robot tool.

[0003] In the related art, methods such as the four-point method or the six-point method of fixed reference point calibration, and an improved point selection method based on a similar kinematic model are used for TCP calibration. The existing solutions rely on the data of each axis of the robot or the specific shape information of the tool, involve complex sensors, and require manual operation to collect data, resulting in human errors. Summary of the Invention

[0004] In order to solve the above technical problems, the present disclosure provides a TCP calibration method, device, equipment and medium for a robot tool.

[0005] In a first aspect, an embodiment of the present disclosure provides a TCP calibration method for a robot tool, including:

[0006] In response to the tool being transformed from an initial posture to a specified posture, controlling the tool to perform a circular motion at each posture;

[0007] According to the light on / off time when the tool performs a circular motion, determining the intersection position of the tool and the measurement plane at each posture; the measurement plane is formed by the intersection of a first light ray and a second light ray, and the light on / off time includes the on / off time of the first light ray and / or the second light ray;

[0008] According to the intersection position of the tool and the measurement plane at each posture, determining the direction information of the tool and the position information of the initial intersection point in the flange coordinate system; the initial intersection point is the intersection point of the tool and the measurement plane in the initial posture;

[0009] In response to controlling the tool to move up and down, according to the light on / off time when the tool moves up and down, determining the tip length from the initial intersection point to the tip of the tool;

[0010] According to the direction information of the tool, the position information of the initial intersection point in the flange coordinate system, and the tip length, determining the TCP calibration result of the tool.

[0011] In a second aspect, an embodiment of the present disclosure provides a TCP calibration device for a robot tool, including:

[0012] A first control module, configured to control the tool to perform a circular motion at each posture in response to the tool being transformed from an initial posture to a specified posture.

[0013] A first determination module, configured to determine the intersection position of the tool and a measurement plane at each posture according to the light on-off time when the tool performs a circular motion; the measurement plane is formed by the intersection of a first light ray and a second light ray, and the light on-off time includes the on-off time of the first light ray and / or the second light ray.

[0014] A processing module, configured to determine the direction information of the tool and the position information of the initial intersection point in the flange coordinate system according to the intersection position of the tool and the measurement plane at each posture; the initial intersection point is the intersection point of the tool and the measurement plane at the initial posture.

[0015] A second determination module, configured to determine the protruding length from the initial intersection point to the tip point of the tool according to the light on-off time when the tool moves up and down in response to controlling the tool to move up and down.

[0016] A calibration module, configured to determine the TCP calibration result of the tool according to the direction information of the tool, the position information of the initial intersection point in the flange coordinate system, and the protruding length.

[0017] In a third aspect, an embodiment of the present disclosure provides an electronic device, including: a processor; a memory for storing executable instructions of the processor; the processor is configured to read the executable instructions from the memory and execute the instructions to implement the TCP calibration method of the robot tool described in the first aspect above.

[0018] In a fourth aspect, an embodiment of the present disclosure provides a computer-readable storage medium, where the storage medium stores a computer program, and when the computer program is executed by a processor, the TCP calibration method of the robot tool described in the first aspect above is implemented.

[0019] The technical solutions provided by the embodiments of the present disclosure have the following advantages compared with the prior art: By setting a measurement plane composed of the intersection of the first light ray and the second light ray, during TCP calibration, the intersection position of the tool and the measurement plane is determined according to the light on / off time when the tool moves in a circular motion, and then the direction information of the tool, the position information of the initial intersection point in the flange coordinate system, and according to the light on / off time when the tool moves up and down, the protruding length from the initial intersection point to the tip point of the tool is determined. Further, according to the direction information of the tool, the position information of the initial intersection point in the flange coordinate system, and the protruding length, the TCP calibration result of the tool is determined. Thus, during TCP calibration, only the light on / off time data collected by the sensor is used. The involved sensor is simpler and allows data errors. It does not need to rely on the data of each axis of the robot or the specific shape information of the tool, and the repeated accuracy of the calculation result is high. In addition, the calibration process is fully automated. Compared with other solutions that require combining manual operations to collect data, this method only needs to execute according to the set parameters, and the calibration process does not require manual intervention, avoiding human errors during data collection and being safe and controllable, reducing labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present disclosure and, together with the specification, are used to explain the principles of the present disclosure.

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a schematic flow chart of a TCP calibration method for a robot tool provided by an embodiment of the present disclosure;

[0023] Figure 2 It is a schematic diagram for TCP calibration;

[0024] Figure 3 It is a schematic diagram of a measurement plane provided by an embodiment of the present disclosure;

[0025] Figure 4 It is a schematic diagram of the measurement principle of circular motion provided by an embodiment of the present disclosure;

[0026] Figure 5 It is a schematic diagram of the measurement principle of up and down motion provided by an embodiment of the present disclosure;

[0027] Figure 6 It is a schematic diagram of solving the normal vector of the ground provided by an embodiment of the present disclosure;

[0028] Figure 7 A schematic diagram of a data acquisition position provided by an embodiment of the present disclosure;

[0029] Figure 8 A schematic diagram of a rigid body motion provided by an embodiment of the present disclosure;

[0030] Figure 9 A schematic diagram of a TCF coordinate plane provided by an embodiment of the present disclosure;

[0031] Figure 10 A schematic diagram of solving the centroid of a flange provided by an embodiment of the present disclosure;

[0032] Figure 11 A schematic diagram of solving the axis angle provided by an embodiment of the present disclosure;

[0033] Figure 12 A schematic diagram of a TCP calibration result provided by an embodiment of the present disclosure;

[0034] Figure 13 A schematic structural diagram of a TCP calibration device for a robot tool provided by an embodiment of the present disclosure. Detailed implementation manners

[0035] In order to more clearly understand the above objects, features and advantages of the present disclosure, the solutions of the present disclosure will be further described below. It should be noted that, without conflict, the embodiments of the present disclosure and the features in the embodiments may be combined with each other.

[0036] Many specific details are set forth in the following description in order to fully understand the present disclosure, but the present disclosure may be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only a part of the embodiments of the present disclosure, rather than all the embodiments.

[0037] Figure 1 A schematic flowchart of a TCP calibration method for a robot tool provided by an embodiment of the present disclosure. The method provided by the embodiment of the present disclosure can be executed by a TCP calibration device for a robot tool. The device can be implemented by software and / or hardware and can be integrated on any electronic device with computing capabilities.

[0038] As Figure 1 shown, the TCP calibration method for a robot tool provided by the embodiment of the present disclosure may include:

[0039] Step 101, in response to the tool being transformed from an initial pose to a specified pose, controlling the tool to perform a circular motion at each pose.

[0040] The method of the embodiment of the present disclosure is applied to the TCP calibration of a robotic tool. The robot includes a tool and a flange. The tool can be a rod-shaped object with central symmetry. The schematic diagram of the TCP calibration is as Figure 2 shown, Figure 2 where E is the flange. The tool is connected to the flange and has an intersection point with the measurement plane. d is the length from the intersection point to the tip of the tool.

[0041] In this embodiment, during the TCP calibration process, the tool corresponds to multiple postures, and the multiple postures include an initial posture and a specified posture. Among them, the initial posture can be the posture corresponding to the tool initially, and the specified posture can be the posture when obtaining corresponding calculation parameters during the TCP calibration process. In the TCP calibration method of the embodiment of the present disclosure, a measurement plane is set. The measurement plane is formed by the intersection of a first light ray and a second light ray, and the first light ray and the second light ray can be realized by a sensor.

[0042] The measurement plane will be described below.

[0043] As an example, the schematic diagram of the sensor is as Figure 3 shown, Figure 3 where the measurement plane is formed by the perpendicular intersection of two light rays, Figure 3 where the dashed lines represent light rays. The measurement plane can be set according to the ground plane, and the measurement plane and the ground plane may not be completely parallel. It should be noted that the above measurement plane is only an example, and the two light rays can also intersect at other angles to form a measurement plane, which is not specifically limited here.

[0044] In this embodiment, for each posture corresponding to the tool, the tool is controlled to perform a circular motion at each posture. The circular motion can be realized by the end of the robot performing a circular motion in the ground plane (the radius size can be set). Through the circular motion, the tool forms a circular-like trajectory in the measurement plane, and at the same time cuts the light rays during the circular motion. The sensor can collect the on-off time caused by the cutting of the light rays in the measurement plane to determine the intersection position of the tool and the measurement plane at each posture.

[0045] Step 102: Determine the intersection position of the tool and the measurement plane at each posture according to the on-off time of the light rays during the circular motion of the tool.

[0046] Among them, the on-off time of the light rays includes the on-off time of the first light ray and / or the second light ray.

[0047] In this embodiment, for each posture, when determining the intersection position between the tool and the measurement plane, the on / off time of the first light ray or the second light ray can be used for calculation. Optionally, according to the on / off time of the light ray and the radius of the circular motion, the intersection position between the tool and the measurement plane is determined by using the calculation method of circular eccentricity. Wherein, the radius of the circular motion is a known quantity set in advance, and the on / off time of the light ray is a measurement value collected by the sensor.

[0048] Step 103: Determine the direction information of the tool and the position information of the initial intersection point in the flange coordinate system according to the intersection positions between the tool and the measurement plane in each posture.

[0049] Wherein, the initial intersection point is the intersection point between the tool and the measurement plane in the initial posture.

[0050] In this embodiment, the intersection positions between the tool and the measurement plane in each posture can be determined through the on / off time of the light ray during the circular motion, and the control parameters for the tool to change from one posture to another can be obtained. Thus, the direction information of the tool and the position information of the initial intersection point in the flange coordinate system can be determined. Wherein, the control parameters include the rigid body change parameter Δtcp sent to the flange.

[0051] The determination of the direction information of the tool will be described below.

[0052] In an embodiment of the present disclosure, the specified posture includes the first posture after the flange is translated a first distance along the three axes of the flange coordinate system respectively. According to the intersection positions between the tool and the measurement plane in each posture, the direction information of the tool is determined, including: determining the target transformation relationship between the flange coordinate system and the measurement plane coordinate system and the direction of the tool axis in the flange coordinate system according to the intersection position between the tool and the measurement plane in the first posture; and determining the direction information of the tool according to the target transformation relationship and the direction of the tool axis in the flange coordinate system.

[0053] In this embodiment, by controlling the flange to be translated a first distance along the axis direction of the flange coordinate system, the tool is transformed to the first posture. Furthermore, based on the intersection position between the tool and the measurement plane in the first posture, the direction information of the tool is estimated through the cross product conclusion. Wherein, the first distances translated along the three axis directions can be the same or different. Taking the initial posture as an example, the flange is controlled to be translated a length one along the x-axis direction of the flange coordinate system to make the tool reach the first posture from the initial posture, and the flange is re-controlled to be translated a length two along the y-axis direction of the flange coordinate system to make the tool reach the second posture from the initial posture, and the flange is re-controlled to be translated a length three along the z-axis direction of the flange coordinate system to make the tool reach the third posture from the initial posture. The intersection positions of the first posture, the second posture, and the third posture are respectively determined. Furthermore, the transformation relationship between the flange coordinate system and the measurement plane coordinate system and the direction r3 of the tool axis in the flange coordinate system are obtained through Determine the direction information λ of the tool.

[0054] Furthermore, for the case where multiple simultaneously meet the accuracy requirements, for example, there are two that simultaneously meet the same accuracy, and the directions of the tools obtained through these two in the measurement plane coordinate system are symmetric about the normal of the measurement plane, and their projections on the measurement plane are located in different coordinate quadrants respectively. In this embodiment, according to the intersection position of the tool and the measurement plane in the first posture, multiple candidate transformation relationships of the flange coordinate system relative to the measurement plane coordinate system and the direction of the tool axis in the flange coordinate system are determined; axial discrimination processing is performed on the multiple candidate transformation relationships to determine the target transformation relationship from the multiple candidate transformation relationships.

[0055] Among them, the axial discrimination processing is described as follows: Control the flange so that the intersection of the tool and the measurement plane is at the center of the measurement plane, and the center of the measurement plane can be the intersection of the light rays. When the intersection is at the center of the measurement plane, control the tool to perform a circular motion once. Furthermore, control the tool to rise or fall a certain distance (which can be set), and then perform a circular motion again after rising or falling. In this step, according to the characteristics of the tool itself, the direction of the tool when rising or falling is along the earth's normal vector. Furthermore, for the coordinates determined by the above two circular motions, the projection component directions are respectively determined, and the candidate transformation relationships that do not meet the preset conditions are eliminated from the multiple candidate transformation relationships according to the projection component directions, so as to determine the target transformation relationship that meets the preset conditions, thereby determining the direction information of the tool.

[0056] The following describes how to determine the position information of the intersection in the flange coordinate system.

[0057] In an embodiment of the present disclosure, the specified posture includes a second posture after the flange performs a preset rigid body motion, where the preset rigid body motion causes the intersection of the tool and the measurement plane to move a second distance along a specified direction, and the specified direction and the second distance can be set as needed. In this embodiment, multiple groups of data can be obtained, and each group of data includes the intersection position of the tool and the measurement plane and the control parameters for the tool to transform from one posture to another posture. According to the multiple groups of data, the position information of the intersection of the tool and the measurement plane in the flange coordinate system in a specific posture can be determined, and thus, the position information of the initial intersection in the flange coordinate system can be determined.

[0058] Step 104, in response to controlling the tool to move up and down, determine the protruding length from the initial intersection to the tip of the tool according to the on-off time of the light when the tool moves up and down.

[0059] In this embodiment, the control tool moves up and down. The up-and-down movement can be that the robot controls the tool to move vertically up and down, so that the tool vertically blocks two light rays in the measurement plane. The sensor can collect the on-off time caused by the blocking of the light rays in the measurement plane to determine the length of the protrusion. Among them, the on-off time of the first light ray and the second light ray can be used for calculation. Optionally, by simplifying the model to a simple harmonic vibration, according to the on-off time of the light ray and the distance of the up-and-down movement, the corresponding calculation method is used to determine the length of the protrusion.

[0060] As an example, after adjusting the axis of the tool to be consistent with the normal vector of the ground, the control tool moves up and down. Among them, the distance of the up-and-down movement is a known quantity set in advance, and the on-off time of the light ray is a measured value collected by the sensor.

[0061] Step 105: Determine the TCP calibration result of the tool according to the direction information of the tool, the position information of the initial intersection point in the flange coordinate system, and the length of the protrusion.

[0062] In this embodiment, referring to Figure 2 the schematic diagram of TCP calibration, the TCP calibration result of the tool can be obtained according to the direction information of the tool, the position information of the initial intersection point in the flange coordinate system, and the length of the protrusion.

[0063] According to the technical solution of the embodiment of the present disclosure, by setting a measurement plane composed of the intersection of the first light ray and the second light ray, during TCP calibration, the intersection position of the tool and the measurement plane is determined according to the on-off time of the light ray during the circular motion of the tool, and then the direction information of the tool and the position information of the initial intersection point in the flange coordinate system are determined. And according to the on-off time of the light ray during the up-and-down movement of the tool, the length of the protrusion from the initial intersection point to the tip of the tool is determined. Further, according to the direction information of the tool, the position information of the initial intersection point in the flange coordinate system, and the length of the protrusion, the TCP calibration result of the tool is determined. Thus, during TCP calibration, only the on-off time data of the light ray collected by the sensor is used. The involved sensor is simpler and allows data errors. It does not need to rely on the data of each axis of the robot or the specific shape information of the tool. The repeated accuracy of the calculation result is high, for example, it can reach within 0.5 mm. In addition, the calibration process is fully automated. Compared with other solutions that require combined manual operation to collect data, this method only needs to execute according to the set parameters, and the calibration process does not require manual intervention, avoiding human errors during data collection and being safe and controllable, and reducing labor costs.

[0064] Based on the above embodiments, the measurement principles of the circular motion and the up-and-down motion are described below.

[0065] For circular motion of the tool, in an embodiment of the present disclosure, the intersection position between the tool and the measurement plane at each posture is determined according to the light on-off time during the circular motion of the tool, including: for each posture, obtaining a first duration for the tool to perform one circular motion and a second duration between any light in the measurement plane being truncated once and being truncated again; determining the intersection position between the tool and the measurement plane according to the radius of the circular motion, the ratio of the second duration to the first duration. Wherein, any light in the measurement plane can be the first light or the second light, and for each posture, the tool can be controlled to perform two circular motions.

[0066] As an example, as Figure 4 shown, the coordinate axis X is set along the light in the measurement plane, and the following formula is used to calculate the coordinates of the center of the circle in the measurement plane, that is, the intersection position between the tool and the measurement plane:

[0067]

[0068] Wherein, t is the second duration, T is the first duration, and R is the radius of the circular motion. The intersection position between the tool and the measurement plane can be determined according to y and the coordinate axis X. Due to the thickness of the tool, Figure 4 the second duration t in

[0069] can be determined by averaging the moments when the tool just cuts the X-axis and just leaves the X-axis, or can be set as needed.

[0070] Thus, the intersection position between the tool and the measurement plane can be accurately calculated through the light on-off time, and only the light on-off time collected by the sensor is used, without relying on the data of each axis of the robot or the specific shape information of the tool, and the calibration system has a simple structure.

[0071] As an example, as Figure 5 shown, the tool longitudinally blocks two lights in the measurement plane, and the tool performs three cycles of up-and-down motion. Assuming that there is an acceleration and deceleration process in the motion, the model can be simplified to a simple harmonic vibration, and the following formula is used to calculate the distance from the intersection point to the tip of the tool:

[0072]

[0073] Wherein, A is the fourth distance, T is the third duration, t is the fourth duration, and h is the distance from the intersection point to the tip of the tool. The fourth duration can be determined according to the first moment when the tool starts to cut and block the light and the second moment when the tool leaves the light. The first moment can be the moment when the first light and the second light are blocked simultaneously, and the second moment can be the moment when the tool first leaves any one of the lights. Due to the instability of the robot movement in the starting stage and the ending stage, in this example, the middle cycle of three cycles can be used for calculation.

[0074] Thus, the distance from the intersection point to the tip of the tool can be accurately calculated through the light on-off time, and only the light on-off time collected by the sensor is used, without relying on the data of each axis of the robot or the specific shape information of the tool, and the calibration system has a simple structure.

[0075] Further, based on the above steps of determining the protruding length by up and down movement, in the embodiment of the present disclosure, controlling the tool to perform up and down movement includes: controlling the tool to move a third distance along a preset direction, and obtaining a first measurement point and a second measurement point before and after moving along the preset direction; determining the normal vector of the ground according to the third distance, the first measurement point and the second measurement point; after the axis of the tool is aligned with the normal vector of the ground, controlling the tool to perform up and down movement.

[0076] The determination of the normal vector of the ground will be described below.

[0077] In an embodiment of the present disclosure, the third distance is preset, and the preset direction is the tool rising or falling. According to the characteristics of the tool itself, the direction when the tool rises or falls is along the normal vector of the ground. Optionally, by controlling the flange, the intersection point of the tool and the measurement plane is made to be at the center of the measurement plane. The center of the measurement plane can be the intersection of the lights. When the intersection point is at the center of the measurement plane, the tool is controlled to perform a circular motion once. Further, the tool is controlled to rise or fall by the third distance, and after rising or falling, a circular motion is performed again. Further, based on the intersection point positions obtained by the two circular motions, combined with the third distance and the direction information of the tool, the normal vector of the ground is solved.

[0078] As an example, referring to Figure 6 , Figure 6 in which the tool is controlled to perform a downward movement, H is the third distance. For example, in the figure, H = -15. The representation of the normal vector of the ground in the measurement plane coordinate system is obtained by using trigonometric functions:

[0079] Where

[0080] Where, is the normal vector of the ground, The direction information of the tool, C1 is the intersection position corresponding to the first circular motion, and C2 is the intersection position corresponding to the second circular motion. Further, after determining the earth normal vector, by moving the initial intersection point of the tool to the center of the measurement plane and rotating it around the center point to the earth normal direction so that the tool axis is consistent with the earth normal vector, and then performing up and down movement to obtain the length from the initial intersection point to the tip point of the tool.

[0081] Based on the above embodiments, the position information of the initial intersection point in the flange coordinate system will be further described below. The position information of the initial intersection point in the flange coordinate system is determined by the foregoing multiple sets of data. Each set of data includes the intersection position and Δtcp. In this step, multiple sets of data can be obtained by solving the flange centroid and the axis-angle motion.

[0082] In an embodiment of the present disclosure, the specified posture includes the second posture after the flange plate performs a preset rigid body motion. The preset rigid body motion causes the intersection point of the tool and the measurement plane to move a second distance along the specified direction. The method further includes: obtaining the flange centroid of the flange plate, the rotation angle and the rotation axis of the preset rigid body motion; determining the target rotation transformation according to the rotation angle and the rotation axis; determining the rigid body change parameters according to the flange centroid and the target rotation transformation, so as to control the flange plate to perform the preset rigid body motion through the rigid body change parameters. Among them, the rotation angle can be determined by the second distance, the preset test angle and the motion distance at the preset test angle, and the rotation axis can be obtained by cross-multiplying and projecting the tool axis and the specified direction.

[0083] As a possible implementation manner, the specified direction includes the direction of the first light ray and the direction of the second light ray. The second distance can be determined according to the size parameters of the tool and the size parameters of the measurement plane, or can be set as required. The method further includes: controlling the flange plate to perform the preset rigid body motion respectively, so that the intersection point of the tool and the measurement plane moves the second distance along the positive direction and the negative direction of the first light ray and the positive direction and the negative direction of the second light ray respectively.

[0084] As an example, as Figure 7 shown, Figure 7 the dotted lines in the figure represent the first light ray and the second light ray, and a is the second distance. In this example, the tool is positioned at a better position to collect data, which is beneficial to model solution, that is, the intersection point position of the tool and the measurement plane is distributed at the four corners of the light rays in the measurement plane as much as possible on the premise of avoiding collision, such as Figure 7 shown, the distances from the four corners to the center of the measurement plane are a.

[0085] To achieve the above position, referring to the schematic diagram of the rigid body motion as Figure 8 shown, Figure 8The A plane, B plane, and L plane are shown, as well as the solid lines 81, 83, the dashed lines 82, 84, and the three axis directions 801, 802, 803 of the TCF coordinate system. Among them, E is a point on the flange, L is the measurement plane, 83 represents the tool, 84 represents the light ray, the 801 direction represents the tool axis direction. Assume that the tool extends infinitely in the opposite direction of the 801 arrow, and the intersection of the current tool and the measurement plane is at the center. The direction 802 represents the direction obtained by the cross product of the tool axis direction and the light ray 84 direction. The B plane is a plane with the direction 802 as the normal and passing through the solid line 81. TCF is a coordinate system formed by the directions 801 and 802 as the coordinate axes. The A plane is a plane with the tool axis direction as the normal and passing through the flange point E. The dashed line 82 is the intersection line of the A plane and the B plane and intersects the tool axis at point O. The solid line 81 is parallel to the 802 direction and passes through point O. It can be seen that keeping the point O on the tool axis stationary and rotating by a certain angle around the solid line 81 passing through point O as the axis can achieve the intersection of the tool and the measurement plane moving a distance a along the light ray.

[0086] To perform the above rigid body motion, the centroid of the flange is solved as follows. After controlling the flange to rotate symmetrically in the positive and negative directions around the tool axis by a certain angle θ (estimated proportionally), two measurement points are obtained in the measurement plane by the method of drawing a circular motion to find the intersection point positions, and the two measurement points are projected onto the TCF coordinate plane (the TCF coordinate plane passes through the center of the measurement plane), as Figure 9 shown. Figure 9 In it, A and B are the projection points, and the center O ′ is calculated for its coordinates in this TCF coordinate system.

[0087] Among them, is the coordinate of the center O ′ in this TCF coordinate system, and O ′ is the centroid of the flange on this TCF coordinate plane.

[0088] Furthermore, the position and attitude of point O in the flange coordinate system are calculated. The specific derivation is as follows: Assume the corresponding relationship as Figure 10 shown, O corresponds to O ′ , E corresponds to E ′ , and the position vector of point O relative to E is the negative of the position vector of point O ′ relative to E ′ . Taking the TCF frame as the attitude of point O, E represents the flange, and L represents the measurement plane, we can obtain:

[0089]

[0090] Thus, the transformation

[0091] The axial angle movement process will be described below.

[0092] In this embodiment, the control flange is made to perform a rigid body movement, so that the intersection point of the tool and the measurement plane moves a certain distance along the four directions of the light ray. Specifically, as described above, it rotates a certain angle β around an axis ( Figure 8 the solid line 81 in ) passing through point O on the tool axis. After moving a certain distance, a circular motion is respectively performed to obtain the intersection point positions in four postures. Refer to Figure 11 , the derivation of the rigid body movement is as follows. First, calculate the rotation angle β through the following formula: xcot(0.1)+(8 - x)cot(α) = 8cot(β), Figure 11 in which a safety angle (0.1) can be tested first to obtain the corresponding intersection point position x, then enlarged to the angle β corresponding to the corresponding position, and then the rotation axis can be calculated. It can be obtained by taking the cross product of the tool axis direction and the light ray to be along and then projecting the cross product result onto the TCF coordinate system. Thus, in the TCF coordinate system with O as the origin, the rotation transformation around point O can be obtained Furthermore, according to the rigid body transformation in the flange coordinate system is obtained, and thus the control parameters for the preset rigid body movement of the flange are determined.

[0093] Based on the above steps, multiple groups of data can be obtained, and then the coordinates of the initial intersection point of the tool and the measurement plane in the flange coordinate system can be calculated. Optionally, the multiple groups of data include the data at the aforementioned four angles, the data after translation along the three axial directions of the flange coordinate system respectively, and the data of symmetric rotation of a certain angle around the positive and negative directions of the tool axis, a total of nine groups of data. In summary, in the actual application process of TCP calibration in the embodiments of the present disclosure, the tool can first be made to intersect at the center of the measurement plane as much as possible, and a circular motion is performed to determine the initial intersection point of the tool and the measurement plane. Then, the steps of controlling the flange to translate along the three axial directions of the flange coordinate system respectively and axial discrimination are sequentially executed to determine the direction information of the tool. The steps of solving the flange orthocenter and axial angle movement are executed to obtain multiple groups of data and determine the position information of the initial intersection point of the tool and the measurement plane in the flange coordinate system. The steps of solving the earth normal vector and the tip length are executed, and then the TCP calibration result is obtained. The schematic diagram of the TCP calibration result can be referred to Figure 12 shown in Figure 12 in, represents the coordinates of the initial intersection point in the flange coordinate system, and d0 represents the tip length.

[0094] Figure 13 is a schematic structural diagram of a TCP calibration device for a robot tool provided by an embodiment of the present disclosure. As Figure 13 shown, the TCP calibration device for the robot tool includes: a first control module 131, a first determination module 132, a processing module 133, a second determination module 134, and a calibration module 135.

[0095] The first control module 131 is configured to control the tool to perform a circular motion at each posture in response to the tool being transformed from an initial posture to a specified posture;

[0096] The first determination module 132 is configured to determine the intersection position of the tool and the measurement plane at each posture according to the light on-off time when the tool performs a circular motion; the measurement plane is formed by the intersection of a first light ray and a second light ray, and the light on-off time includes the on-off time of the first light ray and / or the second light ray;

[0097] The processing module 133 is configured to determine the direction information of the tool and the position information of the initial intersection point in the flange coordinate system according to the intersection position of the tool and the measurement plane at each posture; the initial intersection point is the intersection point of the tool and the measurement plane at the initial posture;

[0098] The second determination module 134 is configured to determine the protruding length from the initial intersection point to the tip point of the tool according to the light on-off time when the tool moves up and down in response to controlling the tool to move up and down;

[0099] The calibration module 135 is configured to determine the TCP calibration result of the tool according to the direction information of the tool, the position information of the initial intersection point in the flange coordinate system, and the protruding length.

[0100] In an embodiment of the present disclosure, the first determination module 132 is specifically configured to:

[0101] For each posture, obtain a first duration for the tool to perform a circular motion once, and a second duration between any light ray in the measurement plane being truncated once and the next truncation;

[0102] Determine the intersection position of the tool and the measurement plane according to the radius of the circular motion, the ratio of the second duration to the first duration.

[0103] In an embodiment of the present disclosure, the specified posture includes a first posture after the flange is translated a first distance along the three axes of the flange coordinate system respectively. The processing module 133 is specifically configured to:

[0104] According to the intersection position of the tool and the measurement plane in the first posture, determine a plurality of candidate transformation relationships of the flange coordinate system relative to the measurement plane coordinate system, and the direction of the tool axis in the flange coordinate system;

[0105] Perform an axial discrimination process on the plurality of candidate transformation relationships to determine a target transformation relationship from the plurality of candidate transformation relationships;

[0106] Determine the direction information of the tool according to the target transformation relationship and the direction of the tool axis in the flange coordinate system.

[0107] In one embodiment of the present disclosure, the specified posture includes the second posture after the flange plate undergoes a preset rigid body motion, and the preset rigid body motion causes the intersection point of the tool and the measurement plane to move a second distance along the specified direction. The device further includes:

[0108] A solution module, configured to obtain the flange centroid of the flange plate, the rotation angle and the rotation axis of the preset rigid body motion; determine the target rotation transformation according to the rotation angle and the rotation axis; and determine the rigid body change parameters according to the flange centroid and the target rotation transformation, so as to control the flange plate to perform the preset rigid body motion through the rigid body change parameters.

[0109] In one embodiment of the present disclosure, the specified direction includes the direction of the first light ray and the direction of the second light ray. The device further includes:

[0110] A movement control module, configured to determine the second distance according to the size parameters of the tool and the size parameters of the measurement plane; and control the flange plate to perform the preset rigid body motion respectively, so that the intersection point of the tool and the measurement plane moves the second distance along the positive direction and the negative direction of the first light ray and the positive direction and the negative direction of the second light ray respectively.

[0111] In one embodiment of the present disclosure, the device further includes:

[0112] A second control module, configured to control the tool to move a third distance along a preset direction, and obtain a first measurement point and a second measurement point before and after moving along the preset direction;

[0113] Determine the earth normal vector according to the third distance, the first measurement point and the second measurement point;

[0114] After controlling the axis of the tool to be consistent with the earth normal vector, control the tool to move up and down.

[0115] In one embodiment of the present disclosure, the second determination module 134 is specifically configured to:

[0116] Obtain the third time period for the tool to perform one up and down movement and the fourth time period for the light ray in the measurement plane to be truncated;

[0117] Determine the tip length according to the fourth distance of the up and down movement and the ratio of the fourth time period to the third time period.

[0118] The TCP calibration device of the robot tool provided by the embodiments of the present disclosure can execute any TCP calibration method of the robot tool provided by the embodiments of the present disclosure, and has the corresponding functional modules and beneficial effects for executing the method. The content not described in detail in the device embodiments of the present disclosure can be referred to the description in any method embodiment of the present disclosure.

[0119] An electronic device provided by an embodiment of the present disclosure includes one or more processors and a memory. The processor may be a central processing unit (CPU) or other forms of processing units with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. The memory may include one or more computer program products, and the computer program products may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. Volatile memory may include, for example, random access memory (RAM) and / or cache memory, etc. Non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage media, and the processor may run the program instructions to implement the methods of the embodiments of the present disclosure above and / or other desired functions. Various contents such as input signals, signal components, noise components, etc. may also be stored in the computer-readable storage media.

[0120] In one example, the electronic device may further include: an input device and an output device, and these components are interconnected through a bus system and / or other forms of connection mechanisms. In addition, the input device may include, for example, a keyboard, a mouse, etc. The output device may output various information to the outside, including the determined distance information, direction information, etc. The output device may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, etc. In addition, according to specific application scenarios, the electronic device may further include any other appropriate components such as a bus, an input / output interface, etc.

[0121] In addition to the above methods and devices, an embodiment of the present disclosure may also be a computer program product, which includes computer program instructions that cause the processor to execute any method provided by the embodiment of the present disclosure when the computer program instructions are run by the processor.

[0122] The computer program product may be written in any combination of one or more programming languages to write program code for performing the operations of the embodiments of the present disclosure. The programming languages include object-oriented programming languages such as Java, C++, etc., and also include conventional procedural programming languages such as the "C" language or similar programming languages. The program code may be executed entirely on the user's computing device, partially on the user's device, executed as an independent software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0123] In addition, an embodiment of the present disclosure may also be a computer-readable storage medium storing computer program instructions, which cause a processor to execute any method provided by the embodiments of the present disclosure when the computer program instructions are run by the processor.

[0124] The computer-readable storage medium may adopt any combination of one or more readable media. The readable media may be a readable signal medium or a readable storage medium. The readable storage medium may include, for example, but not be limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (a non-exhaustive list) of the readable storage medium include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0125] It should be noted that, in this document, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0126] The above are only specific embodiments of the present disclosure, enabling those skilled in the art to understand or implement the present disclosure. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A TCP calibration method for a robotic tool, characterized in that, The method includes: In response to the tool being transformed from an initial posture to a specified posture, controlling the tool to perform a circular motion at each posture; According to the light on-off time when the tool performs a circular motion, determining the intersection position of the tool and the measurement plane at each posture; the measurement plane is formed by the intersection of a first light ray and a second light ray, and the light on-off time includes the on-off time of the first light ray and / or the second light ray; According to the intersection position of the tool and the measurement plane at each posture, determining the direction information of the tool and the position information of the initial intersection point in the flange coordinate system; the initial intersection point is the intersection point of the tool and the measurement plane in the initial posture; In response to controlling the tool to move up and down, according to the light on-off time when the tool moves up and down, determining the protruding length from the initial intersection point to the tip point of the tool; According to the direction information of the tool, the position information of the initial intersection point in the flange coordinate system, and the protruding length, determining the TCP calibration result of the tool.

2. The method according to claim 1, characterized in that, The determining the intersection position of the tool and the measurement plane at each posture according to the light on-off time when the tool performs a circular motion includes: For each posture, obtaining a first duration for the tool to perform a circular motion once and a second duration between one truncation and the next truncation of any light ray in the measurement plane; According to the radius of the circular motion, the ratio of the second duration to the first duration, determining the intersection position of the tool and the measurement plane.

3. The method according to claim 1, wherein The specified posture includes a first posture after the flange plate is translated a first distance along the three axes of the flange coordinate system respectively. The determining the direction information of the tool according to the intersection position of the tool and the measurement plane at each posture includes: According to the intersection position of the tool and the measurement plane in the first posture, determining a plurality of candidate transformation relationships of the flange coordinate system relative to the measurement plane coordinate system and the direction of the tool axis in the flange coordinate system; Performing an axial discrimination process on the plurality of candidate transformation relationships to determine a target transformation relationship from the plurality of candidate transformation relationships; According to the target transformation relationship and the direction of the tool axis in the flange coordinate system, determining the direction information of the tool.

4. The method according to claim 1, characterized in that, The specified posture includes a second posture after the flange plate performs a preset rigid body motion, and the preset rigid body motion causes the intersection point of the tool and the measurement plane to move a second distance along a specified direction. The method further includes: Obtaining the flange centroid of the flange plate, the rotation angle and the rotation axis of the preset rigid body motion; According to the rotation angle and the rotation axis, determining a target rotation transformation; According to the flange centroid and the target rotation transformation, determining rigid body change parameters to control the flange plate to perform a preset rigid body motion through the rigid body change parameters.

5. The method according to claim 4, characterized in that, The specified direction includes the direction of the first light ray and the direction of the second light ray. The method further includes: According to the dimension parameters of the tool and the dimension parameters of the measurement plane, determining the second distance; Control the flange to perform the preset rigid body motion respectively, so that the intersection points of the tool and the measurement plane move the second distance along the positive and negative directions of the first light ray and the positive and negative directions of the second light ray respectively.

6. The method according to claim 1, wherein The controlling the tool to move up and down includes: Control the tool to move a third distance along a preset direction, and obtain a first measurement point and a second measurement point before and after moving along the preset direction; Determine the earth normal vector according to the third distance, the first measurement point and the second measurement point; After controlling the axis of the tool to be consistent with the earth normal vector, control the tool to move up and down.

7. The method according to claim 1, characterized in that The determining the length of the protrusion from the initial intersection point to the tip point of the tool according to the light on-off time when the tool moves up and down includes: Obtain a third duration for the tool to perform one up and down motion and a fourth duration for the light in the measurement plane to be truncated; Determine the length of the protrusion according to the fourth distance of the up and down motion and the ratio of the fourth duration to the third duration.

8. A TCP calibration device for a robotic tool, characterized in that, Includes: A first control module, configured to control the tool to perform a circular motion at each posture in response to the tool being transformed from an initial posture to a specified posture; A first determination module, configured to determine the intersection point position of the tool and the measurement plane at each posture according to the light on-off time when the tool performs a circular motion; the measurement plane is formed by the intersection of a first light ray and a second light ray, and the light on-off time includes the on-off time of the first light ray and / or the second light ray; A processing module, configured to determine the direction information of the tool and the position information of the initial intersection point in the flange coordinate system according to the intersection point positions of the tool and the measurement plane at each posture; the initial intersection point is the intersection point of the tool and the measurement plane in the initial posture; A second determination module, configured to determine the length of the protrusion from the initial intersection point to the tip point of the tool according to the light on-off time when the tool moves up and down in response to controlling the tool to move up and down; A calibration module, configured to determine the TCP calibration result of the tool according to the direction information of the tool, the position information of the initial intersection point in the flange coordinate system and the length of the protrusion.

9. An electronic device, characterized in that, Includes: A processor; A memory for storing executable instructions of the processor; The processor is configured to read the executable instructions from the memory and execute the instructions to implement the TCP calibration method of the robotic tool according to any one of claims 1-7 above.

10. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, and when the computer program is executed by a processor, it implements the TCP calibration method of the robotic tool according to any one of claims 1-7 above.

Images