CN115431278B - Robot calibration method, system and storage medium based on VTK feature point transformation - Google Patents

Robot calibration method, system and storage medium based on VTK feature point transformation Download PDF

Info

Publication number
CN115431278B
CN115431278B CN202211369302.7A CN202211369302A CN115431278B CN 115431278 B CN115431278 B CN 115431278B CN 202211369302 A CN202211369302 A CN 202211369302A CN 115431278 B CN115431278 B CN 115431278B
Authority
CN
China
Prior art keywords
mechanical arm
point
transformation
camera
tail end
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202211369302.7A
Other languages
Chinese (zh)
Other versions
CN115431278A (en
Inventor
周再望
黄志俊
刘金勇
钱坤
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Lancet Robotics Co Ltd
Original Assignee
Lancet Robotics Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Lancet Robotics Co Ltd filed Critical Lancet Robotics Co Ltd
Priority to CN202211369302.7A priority Critical patent/CN115431278B/en
Publication of CN115431278A publication Critical patent/CN115431278A/en
Application granted granted Critical
Publication of CN115431278B publication Critical patent/CN115431278B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J9/00—Programme-controlled manipulators
    • B25J9/16—Programme controls
    • B25J9/1628—Programme controls characterised by the control loop
    • B25J9/1653—Programme controls characterised by the control loop parameters identification, estimation, stiffness, accuracy, error analysis
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J9/00—Programme-controlled manipulators
    • B25J9/16—Programme controls
    • B25J9/1679—Programme controls characterised by the tasks executed
    • B25J9/1692—Calibration of manipulator

Landscapes

  • Engineering & Computer Science (AREA)
  • Robotics (AREA)
  • Mechanical Engineering (AREA)
  • Manipulator (AREA)

Abstract

The invention provides a robot calibration method based on VTK feature point transformation, wherein a reference array for identifying and positioning a camera is fixed at the tail end of a mechanical arm of a robot; s1, keeping the tail end of the mechanical arm unchanged, controlling the tail end of the mechanical arm to move to three different point positions respectively, and obtaining a conversion relation between a positioning camera coordinate system and a mechanical arm base coordinate system and a conversion relation between a TCP coordinate system at the tail end of the mechanical arm and a reference array coordinate system by adopting a VTK characteristic point transformation function; after the attitude of the tail end of the mechanical arm is adjusted, keeping the attitude unchanged, and repeating the process of the step S1; and finally, calculating to obtain the transformation parameters of the coordinate system of the positioning camera and the coordinate system of the mechanical arm base and the transformation parameters of the TCP coordinate system of the mechanical arm tail end and the reference array coordinate system. In the calibration process, the mechanical arm is less in walking times, so that the calibration efficiency is greatly improved; and the coverage area of the tail end of the mechanical arm can be smaller, so that the mechanical arm can be suitable for an operating room with smaller space.

Description

Robot calibration method, system and storage medium based on VTK feature point transformation
Technical Field
The invention relates to the technical field of mechanical arm positioning, in particular to a robot calibration method and system based on VTK characteristic point transformation and a storage medium.
Background
The surgical robot has the advantages of high positioning precision and good repeatability, and is widely applied to image navigation type orthopedic clinical surgery. The navigation and positioning principle of the surgical robot is briefly described as follows: the positioning camera tracks a reference array installed at the tail end of the mechanical arm, and obtains the actual spatial pose of the tail end of the mechanical arm through the transformation relation between a reference array coordinate system and a TCP (tool center point) coordinate system of the tail end of the mechanical arm, so that the mechanical arm is guided to move to the planned target pose. The pose of the TCP at the tail end of the mechanical arm relative to the coordinate system of the base of the mechanical arm can be directly obtained from a control system of the mechanical arm, the conversion relation between the reference array coordinate system at the tail end of the mechanical arm and the TCP coordinate system at the tail end of the mechanical arm needs to be obtained through calibration, and the accuracy of the calibration result directly influences the positioning accuracy of the mechanical arm assisted surgery.
The transformation relationship between the reference array coordinate system of the tail end of the mechanical arm and the TCP coordinate system of the tail end of the mechanical arm (referred to as tail end tool coordinate system transformation relationship for short) can be obtained by the following methods:
the reference array at the tail end of the mechanical arm and the TCP at the tail end of the mechanical arm are in rigid connection, the coordinate system conversion relation of the reference array and the TCP can be measured in a hardware design drawing, and the measurement value is a design value. The value is used for calibrating the mechanical arm base and the hand eye of the positioning camera. On the basis of the hand-eye calibration, acquiring coordinates of verification points on a mechanical arm tail end reference array by using a probe, and correcting a tail end tool coordinate system conversion relation by using the coordinates; the disadvantages of this calibration method are: an error exists between a design value and an assembled object, the error is brought into hand-eye calibration of a mechanical arm base and a positioning camera, and the result of the hand-eye calibration is used for correcting the coordinate system conversion relation of the end tool, so that the correction has locality, and when the tail end posture of the mechanical arm is greatly changed, the correction is not applicable.
Chinese patent publication No. CN113843792A discloses a hand-eye calibration method for a surgical robot, which is to translate the tail end of a robot arm to three positions by keeping the posture of the tail end of the robot arm unchanged relative to a robot arm base, and obtain the rotation relationship between a positioning camera coordinate system and a robot arm base coordinate system through different descriptions of the three positions under the positioning camera coordinate system and the robot arm base coordinate system; and fitting the spherical surface and the spherical center thereof in a mode of keeping the origin of the TCP coordinate system of the mechanical arm still and rotating the reference array at the tail end of the mechanical arm, calculating the translation amount in the coordinate system conversion relation of the tail end tool by using the position of the spherical center, and finally obtaining the complete coordinate system conversion relation of the tail end tool by combining the rotation amount obtained before. The disadvantages of the calibration method are that: when the spherical surface is fitted, the tail end of the mechanical arm rotates around the tail end of the TCP, so that the reference coordinate system is easily shielded, and the reference array is difficult to be visible when being positioned in the whole calibration process.
Chinese patent publication No. CN112525074A discloses a calibration method of a knee joint surgical robot, which uses an improved "nine-point calibration method" to calibrate a hand-eye matrix and a saw-swinging end matrix of the knee joint surgical robot; the disadvantages of the calibration method are that: the tail end of the mechanical arm needs to move for 9 times, the calibration process is complicated, and the efficiency is low; and it needs to cover a larger space range to ensure the global applicability of the calibration result, and the large-range movement of the mechanical arm is limited to an operating room with a smaller space.
Disclosure of Invention
The invention provides a calibration method, a calibration system and a storage medium of an orthopedic robot based on VTK characteristic point transformation technology, which solve the problems that a reference array cannot be captured in the whole process, the calibration process is complicated, the coverage required by a mechanical arm is large and the like in the prior art.
The technical scheme of the invention is realized as follows:
according to one aspect of the invention, a robot calibration method based on VTK feature point transformation is provided, wherein a reference array for identifying and positioning a camera is fixed at the tail end of a mechanical arm of a robot; defining: reference array coordinate system F drf And the TCP coordinate system at the tail end of the mechanical arm is F tcp The mechanical arm base coordinate system is F base The coordinate system of the positioning camera is F camera (ii) a The calibration method comprises the following steps:
step S1, keeping the tail end posture of the mechanical arm unchanged, namely F base To F tcp Is maintained asR 0 The change is not changed; controlling the tail end of the mechanical arm to move to three different positions, namely point A, point B and point C;
when the tail end of the mechanical arm is at the point A, the point B and the point C, F tcp At origin of F base The lower homogeneous coordinates are respectively
Figure DEST_PATH_IMAGE002
，F drf At origin of F camera The lower homogeneous coordinates are respectively
Figure DEST_PATH_IMAGE004
；
When the tail end of the mechanical arm is at the point A, the point B and the point C, F drf At origin of F base The lower homogeneous coordinates are respectively
Figure DEST_PATH_IMAGE006
；
Defining:
Figure DEST_PATH_IMAGE007
the ordered set of points formed is
Figure DEST_PATH_IMAGE009
；
Figure 880540DEST_PATH_IMAGE004
The ordered set of points formed is
Figure DEST_PATH_IMAGE011
；
Figure 418969DEST_PATH_IMAGE006
The ordered set of points formed is
Figure DEST_PATH_IMAGE013
；
Let F tcp To F drf Is a conversion matrix of
Figure DEST_PATH_IMAGE015
；
If the tail end of the mechanical arm is at any position of the points A, B and C, F base To F tcp A translation vector ofTThen F is base To F tcp Is a rotation matrix of
Figure DEST_PATH_IMAGE017
；
Obtained according to the iterative transformation relationship of the coordinate system, F base To F drf Is converted into
Figure DEST_PATH_IMAGE019
；
Let F camera To F base Is a conversion matrix of
Figure DEST_PATH_IMAGE021
；
Then
Figure DEST_PATH_IMAGE023
；
Using the feature point transformation function of the VTK function library, will
Figure DEST_PATH_IMAGE024
Set as the set of target points of the transformation function,
Figure 561938DEST_PATH_IMAGE013
setting an initial point set of a transformation function, and calculating a rigid body space transformation relation between a target point set and the initial point set;
s2, the tail end of the mechanical arm is in a postureR 0 Is changed into
Figure DEST_PATH_IMAGE026
And keeping the tail end of the mechanical arm at the attitude
Figure 578435DEST_PATH_IMAGE026
Keeping the original shape; controlling the end of the mechanical arm to move to
Figure DEST_PATH_IMAGE028
A point is arranged,
Figure DEST_PATH_IMAGE030
A point is arranged,
Figure DEST_PATH_IMAGE032
Pointing at three different locations;
end of mechanical arm is obtained
Figure 686200DEST_PATH_IMAGE028
A point is arranged,
Figure 425223DEST_PATH_IMAGE030
A point is arranged,
Figure 844703DEST_PATH_IMAGE032
At a point of time, F tcp At origin of F base Clear awayThe secondary coordinates are respectively
Figure DEST_PATH_IMAGE034
，F drf At origin of F camera The lower homogeneous coordinates are respectively
Figure DEST_PATH_IMAGE036
；
With the end of the mechanical arm at
Figure 336996DEST_PATH_IMAGE028
A point is arranged,
Figure 423900DEST_PATH_IMAGE030
A point is arranged,
Figure 537088DEST_PATH_IMAGE032
At a point of time, F drf At origin of F base The lower homogeneous coordinates are respectively
Figure DEST_PATH_IMAGE038
；
Defining:
Figure 912705DEST_PATH_IMAGE034
the ordered set of points formed is
Figure DEST_PATH_IMAGE040
；
Figure 536585DEST_PATH_IMAGE036
The ordered set of points formed is
Figure DEST_PATH_IMAGE042
；
Figure DEST_PATH_IMAGE043
The ordered set of points formed is
Figure DEST_PATH_IMAGE045
；
F tcp To F drf Is a conversion matrix of
Figure DEST_PATH_IMAGE047
；
With the end of the mechanical arm at
Figure 55160DEST_PATH_IMAGE028
A point,
Figure 637451DEST_PATH_IMAGE030
A point is arranged,
Figure 31523DEST_PATH_IMAGE032
At any position of the dot, F base To F tcp A translation vector of
Figure DEST_PATH_IMAGE049
Then F is base To F tcp Is a rotation matrix of
Figure DEST_PATH_IMAGE051
；
Obtained according to the iterative transformation relationship of the coordinate system, F base To F drf Is a conversion matrix of
Figure DEST_PATH_IMAGE053
；
F camera To F base Is converted into
Figure DEST_PATH_IMAGE055
；
Then
Figure DEST_PATH_IMAGE057
；
Using the feature point transformation function of the VTK function library, will
Figure DEST_PATH_IMAGE058
Set as the set of target points of the transformation function,
Figure DEST_PATH_IMAGE059
setting the initial point set as transformation function, calculating target point setA rigid body space transformation relation between the starting point set and the initial point set;
step S3, combining the rigid body space transformation relation between the target point set and the starting point set in the step S1 and the step S2, and calculating to obtain F camera To F base Rotational transformation parameter, translational transformation parameter and F tcp To F drf The calibration process of the mechanical arm is completed by changing parameters in a translation way.
As a preferable scheme of the present invention, the reference array comprises a rigid support and at least 3 asymmetrically arranged reflective markers fixedly mounted on the rigid support, and a reference array coordinate system F is established based on any 3 reflective markers therein drf ；F drf At origin of F camera The lower coordinate value can be directly obtained by a positioning camera; the reflective marker can be a reflective ball, a reflective sheet and other markers which can be captured by a positioning camera.
As a preferable aspect of the present invention, the positioning camera is a monocular camera, a binocular camera, or a depth camera.
According to another aspect of the present invention, there is provided a calibration system, comprising a robot, a reference array mounted at the end of a mechanical arm of the robot, and a positioning camera, for performing the above calibration method; the calibration system further comprises:
a first calibration module for obtaining F tcp At origin of F base Lower homogeneous coordinate and F drf At origin of F camera The lower homogeneous coordinate;
a second calibration module for obtaining F base To F drf The transformation matrix of (2);
the first calculation module is respectively connected with the first calibration module and the second calibration module and is used for calculating the rigid body space transformation relation between the target point set and the starting point set;
a second computing module connected with the first computing module for computing F camera To F base Rotational transformation parameter, translational transformation parameter and F tcp To F drf The translation transformation parameters of (1).
According to still another aspect of the present invention, a computer-readable storage medium is provided, in which a computer program is stored, the computer program being executed by a controller to implement the steps of the calibration method described above.
Advantageous effects
Compared with the prior art, the invention has the beneficial effects that:
(1) The calibration method is based on VTK characteristic point transformation function, the obtained conversion relation between the coordinate system of the positioning camera and the coordinate system of the mechanical arm base and the conversion relation between the TCP coordinate system at the tail end of the mechanical arm and the coordinate system of the reference array are all global solutions, the problem that errors exist in the obtained conversion matrix due to the use of design parameters does not exist, and extra calibration is not needed after calibration;
(2) In the walking process of the mechanical arm, the tail end posture of the mechanical arm is kept constant, the tail end posture of the mechanical arm does not need to be changed for multiple times, the reference array at the tail end of the mechanical arm can be always captured by the positioning camera, and the problem that the reference array is shielded does not exist;
(3) In the calibration process, the times of moving the mechanical arm are less, the moving path in the step S1 can be completely the same as that in the step S2, and only the tail end of the mechanical arm has different postures, so that the coverage area of the tail end of the mechanical arm can be smaller, and the mechanical arm can be suitable for an operating room with smaller space; and because the walking times of the mechanical arm are few, the calibration efficiency is greatly improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic diagram of a robot calibration system based on VTK feature point transformation in an embodiment of the present invention.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1, the embodiment provides a robot calibration system based on VTK feature point transformation, where a reference array for identifying and positioning a camera is fixed at the end of a mechanical arm of a robot;
defining: reference array coordinate system F drf And the TCP coordinate system at the tail end of the mechanical arm is F tcp The mechanical arm base coordinate system is F base The coordinate system of the positioning camera is F camera ；
The reference array comprises a rigid support and 4 asymmetrically arranged light-reflecting markers fixedly arranged on the rigid support, and a reference array coordinate system F is established by taking any 3 light-reflecting markers as references drf ；F drf At origin of F camera The lower coordinate value can be directly obtained by a positioning camera; the reflective marker can be a reflective ball, a reflective sheet and other markers which can be captured by the positioning camera, and the positioning reflective sheet is adopted as the reflective marker in the embodiment.
As a preferred scheme of the present invention, the positioning camera is a monocular camera, a binocular camera or a depth camera, and the binocular camera is used as the positioning camera in this embodiment.
The calibration method of the embodiment comprises the following steps:
step S1, keeping the tail end posture of the mechanical arm unchanged, namely F base To F tcp Is maintained asR 0 Keeping the original shape; controlling the tail end of the mechanical arm to move to three different positions of a point A, a point B and a point C respectively;
when the tail end of the mechanical arm is at the point A, the point B and the point C, F tcp At origin of F base The following homogeneous coordinates (which can be obtained by combining the displacement of the tail end of the mechanical arm according to the hardware design parameters of the mechanical arm) are respectively:
Figure DEST_PATH_IMAGE061
F drf at origin of F camera The following homogeneous coordinates (directly obtainable by the positioning camera) are respectively:
Figure DEST_PATH_IMAGE063
when the tail end of the mechanical arm is at the point A, the point B and the point C, F drf At origin of F base The following homogeneous coordinates (unknown) are:
Figure DEST_PATH_IMAGE065
defining:
Figure 556963DEST_PATH_IMAGE007
the ordered set of points formed is
Figure 87301DEST_PATH_IMAGE009
；
Figure 840494DEST_PATH_IMAGE004
The ordered set of points formed is
Figure DEST_PATH_IMAGE066
；
Figure 190704DEST_PATH_IMAGE006
The ordered set of points formed is
Figure 186079DEST_PATH_IMAGE013
；
Let F tcp To F drf Is (unknown) as:
Figure DEST_PATH_IMAGE068
wherein the content of the first and second substances,
Figure DEST_PATH_IMAGE070
is F tcp To F drf The parameters of the rotational transformation of (a),
Figure DEST_PATH_IMAGE072
is F tcp To F drf The translation transformation parameters of (1);
if the tail end of the mechanical arm is at a certain position of the points A, B and C, F base To F tcp A translation vector ofTDue to F base To F tcp Rotation matrix maintenance ofR 0 Not changing, then F base To F tcp Is a rotation matrix of
Figure DEST_PATH_IMAGE073
；
Obtained according to the iterative transformation relationship of the coordinate system, F base To F drf The transformation matrix of (c) is:
Figure DEST_PATH_IMAGE075
i.e. at F base In the following, the first and second parts of the material,
Figure DEST_PATH_IMAGE076
is composed of
Figure 85771DEST_PATH_IMAGE009
Translation
Figure DEST_PATH_IMAGE078
The translation relationship of the two point sets can be described as:
Figure DEST_PATH_IMAGE080
wherein, the first and the second end of the pipe are connected with each other,Iis a 3 × 3 identity matrix;
let F camera To F base The transformation matrix (unknown) of (a) is:
Figure DEST_PATH_IMAGE082
wherein the content of the first and second substances,
Figure DEST_PATH_IMAGE084
is F camera To F base The parameters of the rotational transformation of (a),
Figure DEST_PATH_IMAGE086
is F camera To F base The translation transformation parameters of (1);
then
Figure 354790DEST_PATH_IMAGE076
And
Figure 723454DEST_PATH_IMAGE066
the following transformation relationships exist:
Figure DEST_PATH_IMAGE088
using the feature point transformation function of the VTK function library, will
Figure DEST_PATH_IMAGE089
Set as the set of target points of the transformation function,
Figure 368193DEST_PATH_IMAGE013
setting the initial point set of the transformation function, and calculating the rigid body space transformation relation between the target point set and the initial point set as follows:
Figure DEST_PATH_IMAGE091
namely, it is
Figure DEST_PATH_IMAGE093
Wherein the content of the first and second substances,
Figure DEST_PATH_IMAGE095
converting parameters for rotation between the starting point set and the target point set (the parameters can be directly obtained by calculation from the design parameters of the mechanical arm hardware and positioning data acquired by a positioning camera);
Figure DEST_PATH_IMAGE097
a translation transformation parameter between the starting point set and the target point set (the parameter can be directly obtained by calculation from a mechanical arm hardware design parameter and positioning data acquired by a positioning camera);
Figure DEST_PATH_IMAGE098
、
Figure 184708DEST_PATH_IMAGE086
、
Figure 512659DEST_PATH_IMAGE072
is the unknown to be solved for.
S2, the tail end of the mechanical arm is in a postureR 0 Is changed into
Figure 368620DEST_PATH_IMAGE026
And keeping the tail end of the mechanical arm at the attitude
Figure 410525DEST_PATH_IMAGE026
The change is not changed; controlling the end of the mechanical arm to move to
Figure 769962DEST_PATH_IMAGE028
A point is arranged,
Figure 35859DEST_PATH_IMAGE030
A point is arranged,
Figure 113536DEST_PATH_IMAGE032
The dots are in three different positions (in this embodiment,
Figure 755870DEST_PATH_IMAGE028
a point,
Figure 733928DEST_PATH_IMAGE030
A point is arranged,
Figure 170725DEST_PATH_IMAGE032
The three point positions can be completely superposed with the point A, the point B and the point C in the step S1, so that the activity space of the tail end of the mechanical arm is reduced);
the end of the mechanical arm is obtained
Figure 735699DEST_PATH_IMAGE028
A point is arranged,
Figure 916145DEST_PATH_IMAGE030
A point,
Figure 250174DEST_PATH_IMAGE032
At a point of time, F tcp At origin of F base The following homogeneous coordinates (which can be obtained by combining the displacement of the tail end of the mechanical arm according to the hardware design parameters of the mechanical arm) are respectively:
Figure DEST_PATH_IMAGE100
F drf at origin of F camera The following homogeneous coordinates (directly obtainable by the positioning camera) are respectively:
Figure DEST_PATH_IMAGE102
with the end of the mechanical arm at
Figure 795556DEST_PATH_IMAGE028
A point is arranged,
Figure 352220DEST_PATH_IMAGE030
A point is arranged,
Figure 70777DEST_PATH_IMAGE032
At a point of time, F drf At origin of F base The following homogeneous coordinates (unknown) are:
Figure DEST_PATH_IMAGE104
defining:
Figure 993734DEST_PATH_IMAGE034
the ordered set of points formed is
Figure 37913DEST_PATH_IMAGE040
；
Figure 577479DEST_PATH_IMAGE036
The ordered set of points formed is
Figure 99727DEST_PATH_IMAGE042
；
Figure DEST_PATH_IMAGE105
The ordered set of points formed is
Figure 375726DEST_PATH_IMAGE045
；
F tcp To F drf Is (unknown);
Figure DEST_PATH_IMAGE106
wherein, the first and the second end of the pipe are connected with each other,
Figure 466173DEST_PATH_IMAGE070
is F tcp To F drf The parameters of the rotational transformation of (a),
Figure 227455DEST_PATH_IMAGE072
is F tcp To F drf The translation transformation parameters of (a); these two parameters are fixed and invariant, and are related to the mounting position of the reference array;
machinery installationThe arm ends at
Figure 553394DEST_PATH_IMAGE028
A point is arranged,
Figure 716522DEST_PATH_IMAGE030
A point is arranged,
Figure 335460DEST_PATH_IMAGE032
At any position of the dot, F base To F tcp Is a translation vector of
Figure 849618DEST_PATH_IMAGE049
Then F is base To F tcp Is a rotation matrix of
Figure 713669DEST_PATH_IMAGE051
；
Obtained according to the iterative transformation relationship of the coordinate system, F base To F drf The transformation matrix of (c) is:
Figure DEST_PATH_IMAGE108
namely at F base In the following, the first step is to put the paper into the bag,
Figure 200145DEST_PATH_IMAGE045
is composed of
Figure DEST_PATH_IMAGE109
Translation
Figure DEST_PATH_IMAGE111
The translation relationship of the two point sets can be described as follows:
Figure DEST_PATH_IMAGE113
wherein the content of the first and second substances,Iis a 3 × 3 identity matrix;
F camera to F base Is (unknown) as:
Figure DEST_PATH_IMAGE082A
wherein the content of the first and second substances,
Figure DEST_PATH_IMAGE114
is F camera To F base The parameters of the rotational transformation of (a),
Figure 68613DEST_PATH_IMAGE086
is F camera To F base The translation transformation parameters of (1); these two parameters are fixed because the relative position of the positioning camera and the arm base is constant;
then the
Figure 804488DEST_PATH_IMAGE045
And
Figure 472229DEST_PATH_IMAGE042
the following transformation relationship exists:
Figure DEST_PATH_IMAGE116
using the feature point transformation function of the VTK function library, will
Figure 813212DEST_PATH_IMAGE058
Set as the set of target points of the transformation function,
Figure DEST_PATH_IMAGE117
setting the initial point set of the transformation function, and calculating the rigid body space transformation relation between the target point set and the initial point set as follows:
Figure DEST_PATH_IMAGE119
namely, it is
Figure DEST_PATH_IMAGE121
Wherein the content of the first and second substances,
Figure DEST_PATH_IMAGE123
the method comprises the following steps of (1) converting parameters for rotation between an initial point set and a target point set (the parameters can be directly obtained by calculation from hardware design parameters of a mechanical arm and positioning data acquired by a positioning camera);
Figure DEST_PATH_IMAGE125
translation transformation parameters between the starting point set and the target point set (the parameters can be directly calculated from the design parameters of the hardware of the mechanical arm and positioning data acquired by a positioning camera);
Figure 315563DEST_PATH_IMAGE098
、
Figure 37269DEST_PATH_IMAGE086
、
Figure 243123DEST_PATH_IMAGE072
is the unknown to be solved for.
Step S3, combining the rigid body space transformation relation between the target point set and the starting point set in the step S1 and the step S2, namely
Figure DEST_PATH_IMAGE127
Calculating according to the formula to obtain F camera To F base Rotational transformation parameter of
Figure DEST_PATH_IMAGE128
Translation transformation parameters
Figure 376295DEST_PATH_IMAGE086
And F tcp To F drf Translation transformation parameters of
Figure 274981DEST_PATH_IMAGE072
The calibration of the mechanical arm is completedAnd (5) working procedures.
Correspondingly, the embodiment also provides a calibration system, which comprises a robot, a reference array and a positioning camera, wherein the reference array is installed at the tail end of the mechanical arm of the robot, and the positioning camera is used for executing the calibration method; the calibration system further comprises:
a first calibration module for obtaining F tcp At origin of F base Lower homogeneous coordinate and F drf At origin of F camera The lower homogeneous coordinate;
a second calibration module for obtaining F base To F drf The transformation matrix of (2);
the first calculation module is respectively connected with the first calibration module and the second calibration module and is used for calculating the rigid body space transformation relation between the target point set and the starting point set;
a second computing module connected with the first computing module for computing F camera To F base Rotational transformation parameter, translational transformation parameter and F tcp To F drf The translation transformation parameters of (1).
Accordingly, the present embodiment further provides a computer-readable storage medium, in which a computer program is stored, and the computer program is executed by a controller to implement the steps of the calibration method.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (5)

1. A robot calibration method based on VTK feature point transformation, the end of mechanical arm of the robot is fixed with the reference array used for positioning the camera recognition and positioning; defining: reference array coordinate system F drf And the TCP coordinate system at the tail end of the mechanical arm is F tcp The mechanical arm base coordinate system is F base The coordinate system of the positioning camera is F camera (ii) a The method is characterized by comprising the following steps:
step S1, keeping the tail end posture of the mechanical arm unchanged, namely F base To F tcp Is maintained asR 0 The change is not changed; controlling the tail end of the mechanical arm to move to three different positions of a point A, a point B and a point C respectively;
when the tail end of the mechanical arm is at the point A, the point B and the point C, F tcp At origin of F base The lower homogeneous coordinates are respectively
Figure 396677DEST_PATH_IMAGE001
，F drf At origin of F camera The lower homogeneous coordinates are respectively
Figure 764204DEST_PATH_IMAGE002
；
When the tail end of the mechanical arm is arranged at the point A, the point B and the point C, F drf At origin of F base The lower homogeneous coordinates are respectively
Figure 474671DEST_PATH_IMAGE003
；
Defining:
Figure 953057DEST_PATH_IMAGE001
the ordered set of points formed is
Figure 799791DEST_PATH_IMAGE004
；
Figure 603799DEST_PATH_IMAGE002
The ordered set of points formed is
Figure 535982DEST_PATH_IMAGE005
；
Figure 83638DEST_PATH_IMAGE003
The ordered set of points formed is
Figure 784878DEST_PATH_IMAGE006
；
Let F tcp To F drf Is a conversion matrix of
Figure 783225DEST_PATH_IMAGE007
；
When the tail end of the mechanical arm is at any one of the points A, B and C, F base To F tcp A translation vector ofTThen F is base To F tcp Is a rotation matrix of
Figure 937126DEST_PATH_IMAGE008
；
Obtained according to the iterative transformation relationship of the coordinate system, F base To F drf Is a conversion matrix of
Figure 288473DEST_PATH_IMAGE009
；
Let F camera To F base Is a conversion matrix of
Figure 844219DEST_PATH_IMAGE010
；
Then
Figure 255609DEST_PATH_IMAGE011
；
Using the feature point transformation function of the VTK function library, will
Figure 896806DEST_PATH_IMAGE005
Set as the set of target points of the transformation function,
Figure 520685DEST_PATH_IMAGE004
setting an initial point set of a transformation function, and calculating a rigid body space transformation relation between a target point set and the initial point set;
s2, the tail end of the mechanical arm is in a postureR 0 Is changed into
Figure 462096DEST_PATH_IMAGE012
And keeping the tail end of the mechanical arm at the attitude
Figure 778808DEST_PATH_IMAGE012
The change is not changed; controlling the end of the mechanical arm to move to
Figure 907301DEST_PATH_IMAGE013
A point is arranged,
Figure 600451DEST_PATH_IMAGE014
A point is arranged,
Figure 865210DEST_PATH_IMAGE015
Pointing at three different locations;
calculating a rigid body space transformation relation between the target point set and the starting point set by adopting the same method as the step S1;
step S3, combining the rigid body space transformation relation between the target point set and the starting point set in the step S1 and the step S2, calculating to obtain F camera To F base Rotational transformation parameter, translational transformation parameter and F tcp To F drf The calibration process of the mechanical arm is completed by translating and converting the parameters.
2. The method for calibrating the robot based on VTK characteristic point transformation of claim 1, wherein the reference array comprises a rigid support and at least 3 asymmetrically arranged reflective markers fixedly mounted on the rigid support.
3. The robot calibration method based on VTK feature point transformation of claim 1, wherein the positioning camera is a monocular camera, a binocular camera or a depth camera.
4. A calibration system comprising a robot, a reference array mounted at the end of a robot arm of the robot, and a positioning camera, characterized by being adapted to perform the calibration method of any one of claims 1 to 3; the calibration system further comprises:
a first calibration module for obtaining F tcp At origin of F base Lower homogeneous coordinate and F drf At origin of F camera The lower homogeneous coordinate;
a second calibration module for obtaining F base To F drf The transformation matrix of (2);
the first calculation module is respectively connected with the first calibration module and the second calibration module and is used for calculating the rigid body space transformation relation between the target point set and the starting point set;
a second computing module connected with the first computing module for computing F camera To F base Rotational transformation parameter, translational transformation parameter and F tcp To F drf The translation transformation parameters of (1).
5. A storage medium storing a computer program, characterized in that the computer program is executed by a controller to implement the steps of the calibration method according to any one of claims 1 to 3.
CN202211369302.7A 2022-11-03 2022-11-03 Robot calibration method, system and storage medium based on VTK feature point transformation Active CN115431278B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211369302.7A CN115431278B (en) 2022-11-03 2022-11-03 Robot calibration method, system and storage medium based on VTK feature point transformation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211369302.7A CN115431278B (en) 2022-11-03 2022-11-03 Robot calibration method, system and storage medium based on VTK feature point transformation

Publications (2)

Publication Number Publication Date
CN115431278A CN115431278A (en) 2022-12-06
CN115431278B true CN115431278B (en) 2023-02-14

Family

ID=84252807

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202211369302.7A Active CN115431278B (en) 2022-11-03 2022-11-03 Robot calibration method, system and storage medium based on VTK feature point transformation

Country Status (1)

Country Link
CN (1) CN115431278B (en)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102589437A (en) * 2012-03-09 2012-07-18 天津大学 Calibration method for measuring head center position in light pen-type portable three-coordinate measuring system
CN108942922A (en) * 2018-06-11 2018-12-07 杭州灵西机器人智能科技有限公司 Mechanical arm hand and eye calibrating method, apparatus and system based on circular cone calibration object
CN109443206A (en) * 2018-11-09 2019-03-08 山东大学 Mechanical arm tail end pose measurement system and method based on color spherical fishing light source target
CN109658460A (en) * 2018-12-11 2019-04-19 北京无线电测量研究所 A kind of mechanical arm tail end camera hand and eye calibrating method and system
CN110238851A (en) * 2019-06-14 2019-09-17 苏州大学 A kind of mobile robot and its quick calibrating method and system
CN111775146A (en) * 2020-06-08 2020-10-16 南京航空航天大学 Visual alignment method under industrial mechanical arm multi-station operation
CN112525074A (en) * 2020-11-24 2021-03-19 杭州素问九州医疗科技有限公司 Calibration method, calibration system, robot, computer device and navigation system
CN113263499A (en) * 2021-04-19 2021-08-17 深圳瀚维智能医疗科技有限公司 Mechanical arm hand-eye calibration method, device and system and computer readable storage medium
CN113843792A (en) * 2021-09-23 2021-12-28 四川锋准机器人科技有限公司 Hand-eye calibration method of surgical robot

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102294695A (en) * 2010-06-25 2011-12-28 鸿富锦精密工业（深圳）有限公司 Robot calibration method and calibration system

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102589437A (en) * 2012-03-09 2012-07-18 天津大学 Calibration method for measuring head center position in light pen-type portable three-coordinate measuring system
CN108942922A (en) * 2018-06-11 2018-12-07 杭州灵西机器人智能科技有限公司 Mechanical arm hand and eye calibrating method, apparatus and system based on circular cone calibration object
CN109443206A (en) * 2018-11-09 2019-03-08 山东大学 Mechanical arm tail end pose measurement system and method based on color spherical fishing light source target
CN109658460A (en) * 2018-12-11 2019-04-19 北京无线电测量研究所 A kind of mechanical arm tail end camera hand and eye calibrating method and system
CN110238851A (en) * 2019-06-14 2019-09-17 苏州大学 A kind of mobile robot and its quick calibrating method and system
CN111775146A (en) * 2020-06-08 2020-10-16 南京航空航天大学 Visual alignment method under industrial mechanical arm multi-station operation
CN112525074A (en) * 2020-11-24 2021-03-19 杭州素问九州医疗科技有限公司 Calibration method, calibration system, robot, computer device and navigation system
CN113263499A (en) * 2021-04-19 2021-08-17 深圳瀚维智能医疗科技有限公司 Mechanical arm hand-eye calibration method, device and system and computer readable storage medium
CN113843792A (en) * 2021-09-23 2021-12-28 四川锋准机器人科技有限公司 Hand-eye calibration method of surgical robot

Also Published As

Publication number Publication date
CN115431278A (en) 2022-12-06

Similar Documents

Publication Publication Date Title
CN109974584B (en) Calibration system and calibration method for auxiliary laser osteotomy robot
EP3254621B1 (en) 3d image special calibrator, surgical localizing system and method
CN114041875B (en) Integrated operation positioning navigation system
CN113442169B (en) Method and device for calibrating hands and eyes of robot, computer equipment and readable storage medium
CN113499138B (en) Active navigation system for surgical operation and control method thereof
CN106457562B (en) Method and robot system for calibration machine people
CN113133832B (en) Calibration method and system for double-arm robot puncture system
CN112754616B (en) Ultrasonic positioning puncture system and storage medium
WO2022141153A1 (en) Ultrasonic positioning puncture system and storage medium
CN114343847B (en) Hand-eye calibration method of surgical robot based on optical positioning system
CN111759463A (en) Method for improving positioning precision of surgical mechanical arm
CN110919658A (en) Robot calibration method based on vision and multi-coordinate system closed-loop conversion
CN113974835B (en) Telecentric motionless point constraint-based surgical robot motion control method
CN115222801A (en) Method and device for positioning through X-ray image, X-ray machine and readable storage medium
CN113524201B (en) Active adjusting method and device for pose of mechanical arm, mechanical arm and readable storage medium
JP7258516B2 (en) Calibration method and gripping system
CN115431278B (en) Robot calibration method, system and storage medium based on VTK feature point transformation
CN116942314A (en) Positioning method and system for mixing optical positioning and mechanical positioning
CN115424701A (en) Bone surface follow-up technology about optimal path planning
CN113040910B (en) Calibration method of tracer on tail end of surgical navigation robot
CN113470184A (en) Endoscope augmented reality error compensation method and device
CN117679178B (en) Minimally invasive surgical robot system for traumatic orthopedics department
CN113720261B (en) Plane-based target ball head calibration method, system and application
CN117338422B (en) Space registration and kinematics solver control method, system and device
CN114176787B (en) Control method based on effective working space of surgical robot

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant