CN113916200A

CN113916200A - Calibration system and method for coupling robot and external shaft

Info

Publication number: CN113916200A
Application number: CN202111162778.9A
Authority: CN
Inventors: 郭泽望; 唱丽丽; 张巍; 王凌风; 胡启凡; 于辉勇; 邢飞
Original assignee: Nanjing Zhongke Raycham Laser Technology Co Ltd
Current assignee: Nanjing Zhongke Raycham Laser Technology Co Ltd
Priority date: 2021-09-30
Filing date: 2021-09-30
Publication date: 2022-01-11
Anticipated expiration: 2041-09-30
Also published as: CN113916200B

Abstract

The invention provides a calibration system for coupling a robot and an external shaft, which comprises: a steel needle type calibrator for coupling to a distal shaft flange of the robot; the foldable annular mounting plate is provided with a central hole which is matched and mounted with the steel needle type calibrator, and is sleeved on the steel needle type calibrator and positioned at the position of a light beam emission port in the calibration process; the surface of the reflecting mirror surface is provided with orthogonal cross line marks; an L-shaped bracket, one end of which is connected with the reflector surface and the other end of which is coupled to the external shaft; the joint part of the L-shaped bracket adopts a rotatable adjustment design, and two ends of the L-shaped bracket adopt a telescopic adjustment structure. The calibration system can obviously improve the detection efficiency and precision, and the calibration precision and efficiency do not depend on the experience of operators any more.

Description

Calibration system and method for coupling robot and external shaft

Technical Field

The invention belongs to the technical field of robot and external shaft coupling calibration, and particularly relates to a robot and external shaft coupling rapid calibration device based on vertical reflection.

Background

TCP is the abbreviation of "Tool Central Point", the Chinese name is Tool coordinate Point, TCP of the robot initial state is the terminal shaft flange Central Point, when we let the robot approach a certain Point of the coordinate system in a manual or programming way, it is exactly that let TCP approach this Point. In practice, a tool is fixed on the end flange, such as: the relative position relationship between the action point of the tools and the central point of the flange of the tail end shaft of the robot needs to be known so as to control the running track of the action point, and the process of searching the relative position relationship is called TCP calibration.

The robot and external shaft coupling calibration refers to a process that after the robot finishes TCP (transmission control protocol), the robot finds a relative position between the robot and an external shaft, and is called as the robot and external shaft coupling calibration, the traditional calibration process is to make a small hole mark at a position far away from a plane central point by finding a plane of the external shaft, when people use a manual or programming mode to make the robot approach the hole and observe in different angles to ensure that the tail end of a steel needle of the robot coincides with the small hole without contacting, then rotate or turn over the external shaft for a certain angle, repeat the operation for many times, and realize calibration, the calibration mode is not suitable for observing whether the steel needle and the hole position coincide well, and is easy to collide, so that the measurement result has a large error and is useless, and the efficiency is low.

Disclosure of Invention

It is an object of a first aspect of the present invention to provide a calibration system for coupling a robot to an external axis, comprising:

a steel pin type calibrator for coupling to a distal shaft flange of a robot, the steel pin type calibrator configured to emit a light beam, receive the reflected light beam, and range from the received reflected light beam;

the foldable annular mounting plate is provided with a central hole which is matched and mounted with the steel needle type calibrator, and is sleeved on the steel needle type calibrator and positioned at a light beam emission port in the calibration process;

the surface of the reflecting mirror surface is provided with an orthogonal cross line mark, and in the calibration process, the surface of the reflecting mirror surface faces to the direction of a light beam emission port of the steel needle type calibrator;

an L-shaped bracket, one end of which is connected with the reflector surface and the other end of which is coupled to the external shaft;

the joint part of the L-shaped support adopts a rotatable adjusting design, and two ends of the L-shaped support adopt telescopic adjusting structures.

Preferably, the end of the L-shaped bracket coupled to the other end of the external shaft is provided with a first magnetic attraction part, and the L-shaped bracket is attracted to the surface of the external shaft through the first magnetic attraction part.

Preferably, the steel needle type calibrator has a longitudinal main body part, the main body part defines a first end coupled with a tail end shaft flange of the robot and a second end serving as a light beam emission port, a second magnetic attraction part is arranged at an end part of the first end, and the second magnetic attraction part is attracted to the tail end shaft flange of the robot.

Preferably, the foldable annular mounting plate has fan-shaped folding plates surrounding the central hole and distributed continuously and uniformly in the circumferential direction, each fan-shaped folding plate being arranged to be folded in multiple stages in the radial direction.

Preferably, each of the fan-shaped folding plates is independently operable to be folded or unfolded.

Preferably, the mirror face is flush with the plane of the outer axis.

Preferably, the emitted light beam is a red laser beam, which is driven and excited using a red laser.

The second aspect of the present invention aims to provide a calibration method for coupling a robot with an external shaft, comprising the following steps:

step 1, coupling and connecting two end parts of an L-shaped bracket with a reflector and an external shaft respectively;

step 2, adjusting the L-shaped bracket to enable the reflecting mirror surface to be flush with the plane of the external shaft;

step 3, combining the foldable annular mounting plate with the steel needle type calibrator, namely: sleeving a foldable annular mounting plate on one end of a light beam emitting opening of the steel needle type calibrator through a central hole of the foldable annular mounting plate, enabling the foldable annular mounting plate and the steel needle type calibrator to be in an orthogonal state, and coupling and connecting the other end of the steel needle type calibrator to a tail end shaft flange of a robot;

step 4, connecting the steel needle type calibrator to an upper computer, controlling the emitted light beam through the upper computer and carrying out distance measurement processing according to the returned light beam, and displaying the distance value of the distance measurement result in real time through a display on the surface of the steel needle type calibrator;

step 5, fine and bright light spots emitted by the steel needle type calibrator are aligned with the center of the orthogonal cross line mark of the reflector surface by moving and adjusting the tail end shaft of the robot;

step 6, after the light spot is aligned with the center of the orthogonal cross line mark of the reflector, the light spot of the light beam reflected by the reflector is irradiated on the foldable annular mounting plate by finely adjusting the tail end shaft of the robot, and the light spot of the light beam is positioned at the center of the foldable annular mounting plate, namely the light spot of the light beam returns to the steel needle type calibrator along the center hole of the foldable annular mounting plate and the direction opposite to the emission light path;

and 7, completing one measurement when the following three conditions are met: 1) the light spot generated by the emission light beam is positioned in the center of the orthogonal cross line mark of the reflector surface; 2) the light spot of the reflected light beam returns to the steel needle type calibrator along the central hole of the foldable annular mounting plate and the direction opposite to the emission light path; 3) the steel needle type calibrator receives the returned reflected light beam;

step 8, repeating the processes 2-7 by rotating or overturning the external shaft for a certain angle to complete the second measurement;

and 9, repeating the processes 6 and 7 on the basis of the angle adjusted in the step 8 to finish the third time and the fourth time, so as to realize the final calibration.

Wherein, in the step 6, the method further comprises the following steps:

judging whether the foldable annular mounting plate is mechanically interfered with the tail end shaft/the external shaft of the robot or not according to the posture of the robot, if the foldable annular mounting plate is not mechanically interfered, opening all the fan-shaped folding plates, and if an interference position exists between the tail end shaft/the external shaft of the robot and the foldable annular mounting plate, folding the fan-shaped folding plates at the interference position.

Wherein, in the step 7, the method further comprises the following steps:

and when the conditions 1) to 3) are met, visually representing the steel needle type calibrator.

According to the technical scheme, the calibration system for coupling the robot and the external shaft is optimized through the system design, and comprises L-shaped supports with two telescopic ends, a steel needle type calibration device (integrating red light emission, reflected light collection, target point ranging, feedback signal display and communication support) and a telescopic and foldable annular mounting plate. In the calibration process, a steel needle type calibration device is installed on a flange plate of a tail end shaft of the robot, an annular installation plate is installed on the calibration device, a telescopic L-shaped support is installed on an external shaft, a joint of the telescopic L-shaped support can rotate to facilitate adjustment, the calibration device is used for emitting red light, the robot is manually operated, the red light emitted by the tip end of the steel needle type calibration device is perpendicular to a reflecting mirror surface with an orthogonal cross reticle mark in a space three-dimensional coordinate system, and coupling calibration of the external shaft is achieved.

In the prior calibration mode, a needle-shaped small hole is formed in a plane far away from an external shaft, then a steel needle fixed on a manual mobile robot is aligned with the needle-shaped small hole in the external shaft, and calibration can be realized by aligning the mobile robot and the external shaft for four times, so that collision is easy to occur, and whether alignment is difficult to observe, the measurement precision is reduced, the error range is higher, and the calibration is carried out again.

Compared with the prior art, the calibration system for coupling the robot and the external shaft has the following remarkable beneficial effects and advantages:

1) the steel needle type calibration device can be quickly disassembled and assembled through the design of the magnetic base;

2) the design of the L-shaped bracket is used for being coupled to the reflecting mirror surface and the external shaft, the two ends of the L-shaped bracket can be extended and contracted, and the design with adjustable joints can be used for the external shafts with various shapes and sizes; the tail end of the bracket can be quickly coupled and connected by adopting the design of a magnetic base;

3) the foldable annular mounting plate is suitable for various angles of the robot and avoids interference with the robot due to the design that each sector surface is telescopic and foldable, and collision cannot occur in the calibration process; after the whole device is folded, the device is folded and reduced to form a small annular object, each sector can be opened independently, when the device is completely opened, a large annular plane is formed, the device is convenient to store and use, the large-size unfolded state is ensured to be capable of receiving light spots in the using process, observation and adjustment are facilitated, the problem that the reflected light spots cannot be found right at the beginning is avoided, and meanwhile, a red laser beam is adopted, so that the device is striking and easy to observe;

4) by designing the first indicating module, such as a green light indicating module, the completion of the calibration action can be clearly displayed, and the calibration result and the completion state can be visually observed to perform the next calibration treatment;

5) by designing a first indicating module, such as a distance digital display device, the positions of the calibration device and the external shaft calibration point can be clearly displayed;

6) the calibration system can obviously improve the detection efficiency and precision, and the calibration precision and efficiency do not depend on the experience of operators any more.

It should be understood that all combinations of the foregoing concepts and additional concepts described in greater detail below can be considered as part of the inventive subject matter of this disclosure unless such concepts are mutually inconsistent. In addition, all combinations of claimed subject matter are considered a part of the presently disclosed subject matter.

The foregoing and other aspects, embodiments and features of the present teachings can be more fully understood from the following description taken in conjunction with the accompanying drawings. Additional aspects of the present invention, such as features and/or advantages of exemplary embodiments, will be apparent from the description which follows, or may be learned by practice of specific embodiments in accordance with the teachings of the present invention.

Drawings

The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. Embodiments of various aspects of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of a calibration system for a robot coupled to an external axis according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a steel needle type calibrator according to an embodiment of the present invention.

FIG. 3 is a schematic view of a collapsible annular mounting plate in a fan and collapsed position according to an embodiment of the present invention.

FIG. 4 is a top view of a foldable annular mounting plate in a fan and folded position according to an embodiment of the present invention

Fig. 5 is a schematic diagram of the position of the spot of the emitted beam on the mirror surface according to an embodiment of the present invention, wherein the left side is a schematic diagram before the robot end axis is adjusted and the right side is a schematic diagram after the adjustment so that the spot is aligned with the center of the cross-hair mark of the mirror surface.

Fig. 6 is a schematic diagram of the position of the spot of the reflected beam on the foldable annular mounting plate according to the embodiment of the invention, wherein the left side is a schematic diagram before the adjustment of the robot end shaft, and the right side is a schematic diagram after the adjustment so that the spot of the reflected beam is positioned at the center of the foldable annular mounting plate.

Detailed Description

In order to better understand the technical content of the present invention, specific embodiments are described below with reference to the accompanying drawings.

In this disclosure, aspects of the present invention are described with reference to the accompanying drawings, in which a number of illustrative embodiments are shown. Embodiments of the present disclosure are not necessarily intended to include all aspects of the invention. It should be appreciated that the various concepts and embodiments described above, as well as those described in greater detail below, may be implemented in any of numerous ways, as the disclosed concepts and embodiments are not limited to any one implementation. In addition, some aspects of the present disclosure may be used alone, or in any suitable combination with other aspects of the present disclosure.

Calibration system for coupling robot and external shaft

Referring to fig. 1, a calibration system for coupling a robot to an external axis according to an exemplary embodiment of the present invention includes a steel pin type calibrator 10, a foldable ring-shaped mounting plate 20, a reflecting mirror 30, and an L-shaped bracket 40.

In the calibration system, a foldable ring-shaped mounting plate 20 is orthogonally mounted at a laser beam emitting port of a steel needle type calibrator 10, a reflecting mirror 30 is mounted at one end of an L-shaped bracket 40, and the other end of the L-shaped bracket 40 is coupled to an external shaft 100. In the calibration process, the reflecting mirror surface 30 is adjusted to be flush with the plane of the external shaft 100, the steel needle type calibrator 10 emits red laser beams, and the red laser beams emitted at the tip end of the steel needle type calibrator 10 are orthogonal to the reflecting mirror surface with the cross-shaped scribed lines in a three-dimensional space coordinate system by operating the robot, so that the external shaft coupling calibration is realized.

The L-shaped support 40 is provided with a rotary joint and two telescopic ends, and in the calibration process, the change of the position relation with the external shaft can be realized through the rotation or the overturning of the L-shaped support 40, so that the calibration can be carried out for multiple times.

Therefore, the problem caused by the fact that a small hole mark needs to be marked at a position far away from the central point of the plane on the external axis plane for marking in the prior art can be solved, the robot based on vertical reflection is calibrated by the manual quick calibration device based on the coupling of the robot and the external axis, the reflecting mirror surface can be flush with the surface of the external axis due to the fact that the L-shaped support is adjustable, holes are not formed in the external axis plane, direct contact is not needed in measurement, observation is facilitated by sending red laser beams and collecting reflected beams, and calibration precision and efficiency are greatly improved.

Steel needle type calibrator

A stylus type calibrator 10 for coupling to the distal shaft flange of the robot is provided for emitting a light beam, receiving a reflected light beam, and ranging based on the received reflected light beam.

In the example shown in fig. 1, the stylus type calibration device 10 has a main body portion with a longitudinal shape, the main body portion defines a first end 10A coupled to the end shaft flange of the robot and a second end 10B as a light beam emitting port, and a magnetic attraction portion is disposed at an end of the first end 10A, so that the stylus type calibration device 10 can be attracted to the end shaft flange of the robot through the magnetic attraction portion to achieve quick attraction and matching.

As shown in fig. 1 and 2, the main body is provided with a plurality of functional module designs, including a microprocessor 14, a first indication module 11, a second indication module 12, a communication interface, a laser emitting module 15A, a receiving module 15B, a laser ranging module 15C and a power supply module 19.

It should be understood that the aforementioned communication interfaces, such as 232 communication interface 13A, 485 communication interface 13B, RJ45 network interface 13C, etc., are intended to realize the communication between the steel needle type calibrator 10 and the upper computer.

The aforementioned first indication module 11 and the second indication module 12 may adopt an indication module that provides visual feedback to human eyes, such as an LED display screen, an LCD display screen, an LED indicator light, and the like.

The laser emitting module 15A, for emitting a light beam, for example, preferably a red laser emitting module, can controllably emit a red laser beam, which forms a red spot on the reflecting mirror 30 that is conspicuous and easy to observe, and is easy to adjust and align.

And a receiving module 15B for receiving a reflected beam formed by reflection of the emitted laser beam after reaching the mirror surface 30.

And the laser ranging module 15C is used for performing laser ranging according to the received reflected light beam.

In an alternative embodiment, the laser ranging module 15C may obtain the distance data by using a ranging process based on a TOF method.

In a preferred embodiment, the first indicating module 11 is disposed on the surface of the main body, and is used for indicating that the steel needle type marker receives the reflected light beam, and it preferably uses a green LED indicator, for example, when the reflected light beam is received, the green LED indicator 1s is turned on, the green LED indicator flashes 2 times rapidly, etc., or other means is used to indicate the received reflected light beam.

In a preferred embodiment, the second indicating module 12 is disposed on the surface of the main body, and is used for representing the distance value of the distance measuring result, and it preferably adopts an indicating module capable of displaying digital information, such as an LED display screen.

Foldable annular mounting plate

The foldable annular mounting plate 20 is provided with a central hole 21 which is matched with the steel needle type calibrator 10 for installation, and in the calibration process, the foldable annular mounting plate 20 is sleeved on the steel needle type calibrator through the central hole 21 and is positioned at the position of a light beam emission opening.

The foldable annular mounting plate 20 adopts a foldable telescopic design, is in a smaller annular shape after being folded and reduced, each sector can be independently opened, and a larger annular plane is formed after being completely opened.

Wherein, the foldable annular mounting plate 20 and the steel needle type calibrator 10 are in an orthogonal state (i.e. the central axis is vertical).

As shown in fig. 3 and 4, the foldable annular mounting plate 20 further has fan-shaped folding plates 22 disposed around the central hole 21 and distributed continuously and uniformly in the circumferential direction, and each fan-shaped folding plate 22 is disposed to be folded in multiple stages in the radial direction.

Wherein each fan fold plate 22 can be independently operated to fold or unfold.

It will be appreciated that during calibration, the collapsible annular mounting plate 20 is manipulated into an open position with a large annular flat surface for receiving and viewing, and adjusting the spot of the reflected beam.

Thus, during calibration, when the foldable ring-shaped mounting plate 20 mechanically interferes with the robot/external shaft at an angle, the interfering fan-shaped folding plate 22 can be folded.

Reflecting mirror surface

The mirror surface 30 is connected to an L-shaped bracket 40. Wherein one end of the L-shaped bracket 40 is connected to the bottom of the mirror plate 30. The surface of the mirror surface 30 facing the direction of the light beam emitting port of the steel pin type marker is provided with orthogonal cross-line marks as shown in fig. 1.

L-shaped bracket

An L-shaped bracket 40, in connection with the illustrated example, has one end connected to the bottom of the mirror plate 30 and the other end coupled to an external shaft.

In a preferred embodiment, the end of the L-shaped bracket 40 coupled to the other end of the outer shaft is provided with a magnetic attraction portion, through which the L-shaped bracket is attracted to the surface of the outer shaft 100.

In the preferred embodiment, the joint of the L-shaped bracket 40 is designed to be rotatably adjustable, for example, to be omni-directionally adjustable by 360 °, and the two ends of the L-shaped bracket are both telescopically adjustable. In this manner, multiple angular and positional adjustments may be achieved.

Calibration method

With reference to fig. 1, 5, and 6, a calibration process of coupling a robot and an external axis by using a calibration system provided by an embodiment of the present invention includes the following steps:

step 1, coupling two end parts of an L-shaped bracket 40 with a reflector 30 and an external shaft 100 respectively;

step 2, the reflecting mirror surface 30 is aligned with the plane of the external shaft 100 by adjusting the L-shaped bracket 40;

step 3, combining the foldable annular mounting plate 20 with the steel needle type calibrator 10, namely: sleeving a foldable annular mounting plate 20 on one end of a light beam emitting opening of the steel needle type calibrator 10 through a central hole 21 of the foldable annular mounting plate, enabling the foldable annular mounting plate and the steel needle type calibrator to be in an orthogonal state, and coupling and connecting the other end of the steel needle type calibrator 10 to a tail end shaft flange of a robot in a coupling manner, for example, performing quick coupling connection through a magnetic part;

step 4, connecting the steel needle type calibrator 10 to an upper computer, controlling the emitted light beam and performing distance measurement processing according to the returned reflected light beam by the upper computer, and displaying the distance value of the distance measurement result in real time through a display (such as a second indication module 12) on the surface of the steel needle type calibrator 10;

step 5, by moving and adjusting the tail end shaft of the robot, the fine and bright light spots (namely emission light spots) formed by the light beams 16 emitted by the steel needle type calibration device 10 are aligned with the centers of the orthogonal cross line marks of the reflecting mirror surface, as shown in fig. 5; the tiny bright light spots particularly mean light spots with extremely tiny light spot sizes and bright sizes lower than 1 mm; especially red light spots as described above to facilitate viewing;

step 6, after the light spot is aligned with the center of the orthogonal cross mark of the reflector 30, the tail end shaft of the robot is finely adjusted, so that the light spot formed by the reflected light beam 18 reflected by the reflector 30 (i.e. the reflected light spot) is irradiated on the foldable annular mounting plate 20, and the light spot formed by the reflected light beam is positioned at the center of the foldable annular mounting plate 20, as shown in fig. 6, namely the light spot formed by the reflected light beam returns to the steel needle type calibrator 10 along the central hole 21 of the foldable annular mounting plate and the direction opposite to the emission light path;

and 7, completing measurement calibration once when the following three conditions are achieved: 1) the light spot generated by the emission light beam is positioned in the center of the orthogonal cross line mark of the reflector surface; 2) the light spot of the reflected light beam returns to the steel needle type calibrator along the central hole of the foldable annular mounting plate and the direction opposite to the emission light path; 3) the steel needle type calibrator receives the returned reflected light beam;

step 8, repeating the processes 2-7 by rotating or overturning the external shaft for a certain angle to finish the second measurement calibration;

In an optional embodiment, in the step 6, the following steps are further included:

whether the foldable ring-shaped mounting plate 20 is mechanically interfered with the end shaft/outer shaft of the robot is judged according to the posture of the robot, if the mechanical interference does not occur, all the fan-shaped folding plates are opened, and if an interference position exists between the end shaft/outer shaft of the robot and the foldable ring-shaped mounting plate, the fan-shaped folding plate at the interference position is folded.

In an optional embodiment, the step 7 further includes the following steps:

when the conditions 1) -3) are all satisfied, visually characterizing on the steel needle type calibrator, for example by the aforementioned first indicator module 11.

In this embodiment, the green LED indicator quickly flashes 2 times to prompt completion of one measurement calibration.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims

1. A calibration system for coupling a robot to an external shaft, comprising:

2. The calibration system of claim 1, wherein the end of the L-shaped bracket coupled to the other end of the external shaft is provided with a first magnetic attraction part, and the first magnetic attraction part is attracted to the surface of the external shaft.

3. The system of claim 1, wherein the pin-type steel calibrator has a main body with a longitudinal shape, the main body defines a first end coupled to the shaft flange at the end of the robot and a second end serving as a light beam emitting port, and the first end is provided with a second magnetic attraction unit at an end thereof and attracted to the shaft flange at the end of the robot by the second magnetic attraction unit.

4. The system of claim 3, wherein the main body has a laser emitting module for emitting a beam, a receiving module for receiving a beam, and a laser ranging module for detecting a distance according to the beam.

5. A calibration system for coupling a robot to an external shaft according to claim 3, wherein the surface of the main body part is provided with a first indication module for indicating that the steel needle type calibrator receives the reflected light beam.

6. A calibration system for coupling a robot to an external shaft according to claim 3, wherein the surface of the main body part is provided with a second indication module for distance values characterizing the distance measurement results.

7. A calibration system for coupling a robot to an external shaft according to claim 3, wherein the main body part is further provided with a communication interface.

8. Calibration system for coupling a robot to an external shaft according to any of claims 1-7, characterized in that the foldable annular mounting plate has sector folding plates surrounding a central hole and being continuous and evenly distributed in the circumferential direction, each sector folding plate being arranged to be folded in multiple stages in the radial direction.

9. A calibration system for coupling a robot to an external shaft according to claim 8, wherein each of the fan-shaped folding plates is operable to fold or unfold independently.

10. A calibration system for a robot coupled to an external axis according to claim 1 wherein the mirror surface is flush with the plane of the external axis.

11. Calibration method for a calibration system for a robot coupled to an external shaft according to any of the claims 1-10, characterized in that it comprises the following steps:

12. The calibration method for a calibration system of a robot coupled with an external shaft according to claim 11, wherein the step 6 further comprises the steps of:

13. The calibration method for a calibration system of a robot coupled with an external shaft according to claim 11, wherein the step 7 further comprises the steps of: