CN108393928B - Multi-rigid-finite-element hybrid analysis method for contact collision of mechanical arm of flexible robot - Google Patents
Multi-rigid-finite-element hybrid analysis method for contact collision of mechanical arm of flexible robot Download PDFInfo
- Publication number
- CN108393928B CN108393928B CN201810076053.XA CN201810076053A CN108393928B CN 108393928 B CN108393928 B CN 108393928B CN 201810076053 A CN201810076053 A CN 201810076053A CN 108393928 B CN108393928 B CN 108393928B
- Authority
- CN
- China
- Prior art keywords
- rigid
- mechanical arm
- finite
- contact
- flexible robot
- 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.)
- Expired - Fee Related
Links
- 238000004458 analytical method Methods 0.000 title claims abstract description 35
- 238000004364 calculation method Methods 0.000 claims abstract description 24
- 238000000034 method Methods 0.000 claims abstract description 20
- 239000000463 material Substances 0.000 claims description 13
- 238000013016 damping Methods 0.000 claims description 5
- 238000000926 separation method Methods 0.000 claims description 5
- 238000006243 chemical reaction Methods 0.000 claims description 4
- 230000003252 repetitive effect Effects 0.000 abstract description 2
- 241000282414 Homo sapiens Species 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 210000001503 joint Anatomy 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J19/00—Accessories fitted to manipulators, e.g. for monitoring, for viewing; Safety devices combined with or specially adapted for use in connection with manipulators
- B25J19/0095—Means or methods for testing manipulators
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J19/00—Accessories fitted to manipulators, e.g. for monitoring, for viewing; Safety devices combined with or specially adapted for use in connection with manipulators
- B25J19/007—Means or methods for designing or fabricating manipulators
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J9/00—Programme-controlled manipulators
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
- G06F30/23—Design optimisation, verification or simulation using finite element methods [FEM] or finite difference methods [FDM]
Landscapes
- Engineering & Computer Science (AREA)
- Robotics (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Computer Hardware Design (AREA)
- Evolutionary Computation (AREA)
- Geometry (AREA)
- General Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Numerical Control (AREA)
Abstract
The invention discloses a multi-rigid-finite element mixed analysis method for contact collision of a flexible robot mechanical arm, which utilizes an equivalent unit to simulate a hinge bolt and a spring in a finite element model; in the calculation process, when the mechanical arm is not in contact, the rigid body algorithm is adopted by the mechanical arm, and when the mechanical arm is in contact, the multi-rigid body/finite element mixed analysis is carried out by adopting the deformation body algorithm. The invention solves the problems of low calculation efficiency and low calculation precision of the contact collision problem of the robot mechanical arm. When the contact collision of the robot mechanical arm is analyzed, the rigid body and the deformable body can be converted only by changing the K file, so that the repetitive work is reduced, the technical time is shortened, and the working efficiency is improved.
Description
Technical Field
The invention belongs to a contact collision analysis technology, and particularly relates to a multi-rigid-finite-element mixed analysis method for contact collision of a mechanical arm of a flexible robot.
Background
With the development of science and technology, robotic arms have been widely used in various fields, such as: aerospace, deep sea exploration, industrial, agricultural, and the like. Contact impact is also a common problem for robotic arms in engineering and domestic applications.
The contact collision is closely related to the life of human beings, and has advantages and disadvantages for the production and the life of human beings, such as: the friction impact of the foot and the ground when walking, the contact collision in the butt joint process of the space detector, the braking and collision of the automobile and the like. In dealing with the problem of contact collision, the main objective is to eliminate the adverse effects of contact collision, such as reducing the wear of the mechanical structure, increasing the service life of the machine, and avoiding the extra loss of energy. The problem of contact collision has been studied by related scholars since a long time ago, and a plurality of related theories are obtained and widely applied to the mechanical field. However, the process of contact collision is a very complicated process, and many difficulties still remain unsolved at present.
In a related study to perform contact impact analysis, a simple method to describe the dynamic contact problem employs a rigid body algorithm, without considering the deformation of the object. Although the calculation time is short by adopting the rigid body algorithm, a recovery coefficient needs to be introduced, the calculation precision of the rigid body algorithm is low, and the deformation or the stress wave of the contact area cannot be obtained.
The complex method considers that the object is a deformable body, adopts an elastic algorithm and uses a finite element method or a boundary element method for calculation. Although the elastic algorithm has high calculation precision and can obtain data which cannot be obtained in some rigid algorithms, the calculation amount is large, and the result cannot be obtained due to the large calculation amount.
Disclosure of Invention
The invention aims to provide a multi-rigid-finite element mixed analysis method for contact collision of a flexible robot mechanical arm, which solves the problems of low computational efficiency and low computational accuracy of finite element analysis of the existing robot mechanical arm contact collision problem.
The technical solution for realizing the purpose of the invention is as follows: a multi-rigid-finite element hybrid analysis method for contact collision of a flexible robot mechanical arm comprises the following steps:
step S1, establishing a three-dimensional CAD model of the flexible robot mechanical arm;
step S2, checking the established three-dimensional CAD model;
step S3, importing the three-dimensional CAD model obtained in the step S1 into a Hypermesh pretreatment environment;
step S4, removing the hinge bolt and the spring in the three-dimensional CAD model obtained in step S1, and dividing the remaining mechanical arm part into grids;
a step S5 of establishing a rotary hinge unit at the position of the hinge bolt deleted in the step S4 while establishing a spring unit thereat;
step S6, defining and assigning the unit properties and material parameters of the arm portion and the spring unit;
and step S7, adding loads and constraints, generating a K file solved by a nonlinear finite element solver, and turning to step 2.
step S8, determining the contact start time and the contact separation time by calculation;
step S9, opening the K file generated in the step S7, modifying the K file, adding sentences used for converting rigid bodies and deformable bodies, and generating a new K file;
in step S10, the new K file generated in step S9 is imported to a nonlinear finite element solver for analysis and data processing.
Compared with the prior art, the invention has the remarkable advantages that: and simulating the hinge bolt and the spring in the finite element model by using the equivalent unit, and performing local more detailed treatment on the contact area. In the calculation process, when the mechanical arm is not in contact, the rigid body algorithm is adopted by the mechanical arm, and when the mechanical arm is in contact, the deformation body algorithm is adopted to perform multi-rigid-finite element mixed analysis. When the contact collision of the robot mechanical arm is analyzed, the rigid body and the deformable body can be converted only by changing the K file, so that the repetitive work is reduced, the technical time is shortened, and the working efficiency is improved.
Drawings
Fig. 1 is a flow chart of a multi-rigid-finite-element hybrid analysis method for contact collision of a flexible robot mechanical arm according to a preferred embodiment of the present invention.
Fig. 2 is a node and graph of a spring unit provided in a preferred embodiment of the present invention.
Fig. 3 is a finite element model provided by a flexible robotic arm according to a preferred embodiment of the present invention.
Detailed Description
The present invention is described in further detail below with reference to the attached drawing figures.
Referring to fig. 1, a multi-rigid-finite element hybrid analysis method for contact collision of a flexible robot mechanical arm includes the following steps:
step S1, establishing a three-dimensional CAD model of the flexible robot mechanical arm;
step S2, checking the established three-dimensional CAD model;
step S3, importing the three-dimensional CAD model obtained in the step S1 into a Hypermesh pretreatment environment;
step S4, removing the hinge bolt and the spring in the three-dimensional CAD model obtained in step S1, and dividing the remaining mechanical arm part into grids;
a step S5 of establishing a rotary hinge unit at the position of the hinge bolt deleted in the step S4 while establishing a spring unit thereat;
step S6, defining and assigning the unit properties and material parameters of the arm portion and the spring unit;
and step S7, adding loads and constraints, generating a K file solved by a nonlinear finite element solver, and turning to step 2.
step S8, determining the contact start time and the contact separation time by calculation;
step S9, opening the K file generated in the step S7, modifying the K file, adding sentences used for converting rigid bodies and deformable bodies, and generating a new K file; the keywords in the K file for conversion between the rigid body and the deformable body are as follows:
*DEFORMABLE_TO_RIGID_AUTOMATIC 。
in step S10, the new K file generated in step S9 is imported to a nonlinear finite element solver for analysis and data processing.
The spring unit is a torsion spring unit, and the parameters of the torsion spring unit are a stiffness coefficient k and a damping coefficient c.
The material attribute of the rigid body algorithm is set as a rigid body, and the material of the deformable body algorithm is set as a deformable body or an elastic-plastic body.
The rigid body and the deformable body adopt the same material parameters, and the rigid body and the elastic plastic body adopt the same material parameters.
Example 1
As shown in fig. 3, the modules of the flexible robot arm include a fixed disk 1, a dual link arm connecting shaft 2, a first link 3, a spring 4, a hinge bolt 5, a second link 6, and a sliding plate 7. The fixed disk 1 is fixed on a certain mechanism, one end of the double-connecting-rod connecting shaft 2 is fixedly connected with the fixed disk 1, and the other end of the double-connecting-rod connecting shaft is rotatably connected with one end of the first connecting rod 3. The other end of the first connecting rod 3 is rotatably connected with one end of a second connecting rod 6 through a spring 4 and a hinge shaft 5, and the other end of the second connecting rod 6 is contacted with a sliding flat plate 7.
In this embodiment, the equivalent unit is a rotation hinge unit and a spring unit, the rotation hinge unit simulates a hinge bolt of the finite element model, and the spring unit simulates a spring in the finite element model. As shown in fig. 2, the two ends of the spring unit respectively have an I node and a J node, and the parameters of the spring unit further include a stiffness coefficient k and a damping coefficient c. Performing local more detailed treatment on the contact area; in the calculation process, when the mechanical arm is not in contact, the rigid body algorithm is adopted by the mechanical arm, and when the mechanical arm is in contact, the multi-rigid body/finite element mixed analysis is carried out by adopting the deformation body algorithm.
When the mechanical arm is not in contact, two stages of separation before and after the contact are referred to.
The invention relates to a multi-rigid-finite element mixed analysis method for contact collision of a flexible robot mechanical arm, which comprises the following specific steps:
step S1, establishing a three-dimensional CAD model of the flexible robot mechanical arm;
step S2, checking the established three-dimensional CAD model;
step S3, importing the three-dimensional CAD model obtained in the step S1 into a Hypermesh pretreatment environment;
step S4, removing the hinge bolt and the spring in the three-dimensional CAD model obtained in step S1, and dividing the remaining mechanical arm part into grids;
a step S5 of establishing a rotary hinge unit at the position of the hinge bolt deleted in the step S4 while establishing a spring unit thereat;
step S6, defining and assigning the unit properties and material parameters of the arm portion and the spring unit;
and step S7, adding loads and constraints, generating a K file solved by a nonlinear finite element solver, and turning to step 2.
step S8, determining the contact start time and the contact separation time by calculation;
step S9, opening the K file generated in the step S7, modifying the K file, adding sentences used for converting rigid bodies and deformable bodies, and generating a new K file; the keywords in the K file for conversion between the rigid body and the deformable body are as follows:
*DEFORMABLE_TO_RIGID_AUTOMATIC 。
in step S10, the new K file generated in step S9 is imported to a nonlinear finite element solver for analysis and data processing.
In the Hypermesh unit library, the spring unit has axial and torsional properties, and by utilizing the torsional property of the spring unit, the name of the spring unit in Hypermesh is spring, and parameters required to be determined during use are as follows: the stiffness coefficient k and the damping coefficient c are determined by the actual spring parameters.
In Hypermesh, the hinge bolt is removed while the swivel hinge unit and the spring unit are established at the hinge.
In order to analyze the contact collision of the flexible robot mechanical arm, considering that the movement time of the mechanical arm before contact is larger than the time of the contact process, and considering that the calculation time is saved, the movement of the robot mechanical arm before contact can be calculated by a multi-rigid-body algorithm; elastic vibration caused by collision gradually disappears due to material damping, and the object motion is mainly represented as rigid motion, so that calculation is preferably performed by using a multi-rigid-body algorithm; however, during the contact process of the object, the frequency of the contact force is very high and the amplitude is very large, and the deformation of the object must be considered, and finite element calculation is preferably used. Therefore, the purposes that only the deformation body algorithm is used for calculation in the contact collision process and the multi-rigid body algorithm is used for calculation in other motion processes can be achieved through modification of the K file of the LS-DYNA.
Claims (8)
1. A multi-rigid-finite element hybrid analysis method for contact collision of a flexible robot mechanical arm is characterized by comprising the following steps:
step 1, simulating bolts and springs in a finite element model of the flexible robot mechanical arm by using an equivalent unit, and turning to step 2;
step 2, in the calculation process, when the flexible robot mechanical arm is not in contact, a rigid body algorithm is adopted to perform multi-rigid body/finite element mixed analysis; and performing multi-rigid body/finite element mixed analysis by adopting a deformable body algorithm during contact.
2. The multi-rigid-finite-element hybrid analysis method for contact collision of the flexible robot mechanical arm according to claim 1, wherein: in the step 1, the equivalent unit comprises a rotary hinge unit and a spring unit, the rotary hinge unit simulates a hinge bolt of the finite element model, and the spring unit simulates a spring in the finite element model.
3. The multi-rigid-finite-element hybrid analysis method for the contact collision of the flexible robot mechanical arm according to claim 1 or 2, wherein in the step 1, the bolt and the spring in the finite-element model of the flexible robot mechanical arm are simulated by using the equivalent unit, and the specific steps are as follows:
step S1, establishing a three-dimensional CAD model of the flexible robot mechanical arm;
step S2, checking the established three-dimensional CAD model;
step S3, importing the three-dimensional CAD model obtained in the step S1 into a Hypermesh pretreatment environment;
step S4, removing the hinge bolt and the spring in the three-dimensional CAD model obtained in step S1, and dividing the remaining mechanical arm part into grids;
a step S5 of establishing a rotary hinge unit at the position of the hinge bolt deleted in the step S4 while establishing a spring unit thereat;
step S6, defining and assigning the unit properties and material parameters of the arm portion and the spring unit;
and step S7, adding loads and constraints, generating a K file solved by a nonlinear finite element solver, and turning to step 2.
4. The multi-rigid-finite-element hybrid analysis method for contact collision of the flexible robot mechanical arm according to claim 3, wherein the spring unit is a torsion spring unit, and the parameters are a stiffness coefficient k and a damping coefficient c.
5. The multi-rigid-finite-element hybrid analysis method for contact collision of the flexible robot mechanical arm according to claim 3, wherein: in the step 2, the specific steps of the rigid algorithm and the deformable body algorithm conversion are as follows:
step S8, determining the contact start time and the contact separation time by calculation;
step S9, opening the K file generated in the step S7, modifying the K file, adding sentences used for converting rigid bodies and deformable bodies, and generating a new K file;
in step S10, the new K file generated in step S9 is imported to a nonlinear finite element solver for analysis and data processing.
6. The multi-rigid-finite-element hybrid analysis method for contact collision of the flexible robot mechanical arm according to claim 5, wherein: the keywords added into the new K file generated by the sentence for converting the rigid body and the deformable body are as follows:
*DEFORMABLE_TO_RIGID_AUTOMATIC 。
7. the multi-rigid-finite-element hybrid analysis method for contact collision of the flexible robot mechanical arm according to claim 5, wherein: the material attribute of the rigid body algorithm is set as a rigid body, and the material of the deformable body algorithm is set as a deformable body or an elastic-plastic body.
8. The multi-rigid-finite-element hybrid analysis method for contact collision of the flexible robot mechanical arm according to claim 7, wherein: the rigid body and the deformable body adopt the same material parameters, and the rigid body and the elastic plastic body adopt the same material parameters.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810076053.XA CN108393928B (en) | 2018-01-26 | 2018-01-26 | Multi-rigid-finite-element hybrid analysis method for contact collision of mechanical arm of flexible robot |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810076053.XA CN108393928B (en) | 2018-01-26 | 2018-01-26 | Multi-rigid-finite-element hybrid analysis method for contact collision of mechanical arm of flexible robot |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108393928A CN108393928A (en) | 2018-08-14 |
| CN108393928B true CN108393928B (en) | 2020-06-30 |
Family
ID=63094967
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810076053.XA Expired - Fee Related CN108393928B (en) | 2018-01-26 | 2018-01-26 | Multi-rigid-finite-element hybrid analysis method for contact collision of mechanical arm of flexible robot |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108393928B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112131658B (en) * | 2020-08-28 | 2022-10-28 | 南京理工大学 | Automobile bumper and railing collision finite element analysis method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102222137A (en) * | 2011-05-30 | 2011-10-19 | 山东理工大学 | Fire-fighting robot arm double-coupling simulation method |
| CN102540881A (en) * | 2012-02-17 | 2012-07-04 | 国电科学技术研究院 | Design method for boundary control law of Flexible mechanical arm-based partial differential equation model |
| CN102637228A (en) * | 2012-04-05 | 2012-08-15 | 天津大学 | Serial robot structural design optimization method |
| CN105760576A (en) * | 2016-01-27 | 2016-07-13 | 首都师范大学 | Formalized analyzing method and system for mechanical arm motion planning on basis of conformal geometric algebra |
| CN106737855A (en) * | 2016-08-22 | 2017-05-31 | 南京理工大学 | A kind of robot precision compensation method of comprehensive position and attitude error model and rigidity compensation |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8751040B2 (en) * | 2010-04-02 | 2014-06-10 | GM Global Technology Operations LLC | Systems and methods for evaluating braking performance |
-
2018
- 2018-01-26 CN CN201810076053.XA patent/CN108393928B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102222137A (en) * | 2011-05-30 | 2011-10-19 | 山东理工大学 | Fire-fighting robot arm double-coupling simulation method |
| CN102540881A (en) * | 2012-02-17 | 2012-07-04 | 国电科学技术研究院 | Design method for boundary control law of Flexible mechanical arm-based partial differential equation model |
| CN102637228A (en) * | 2012-04-05 | 2012-08-15 | 天津大学 | Serial robot structural design optimization method |
| CN105760576A (en) * | 2016-01-27 | 2016-07-13 | 首都师范大学 | Formalized analyzing method and system for mechanical arm motion planning on basis of conformal geometric algebra |
| CN106737855A (en) * | 2016-08-22 | 2017-05-31 | 南京理工大学 | A kind of robot precision compensation method of comprehensive position and attitude error model and rigidity compensation |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108393928A (en) | 2018-08-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Liu et al. | Dynamics and control of a spatial rigid-flexible multibody system with multiple cylindrical clearance joints | |
| Erkaya | Prediction of vibration characteristics of a planar mechanism having imperfect joints using neural network | |
| Bascetta et al. | Closed form Newton–Euler dynamic model of flexible manipulators | |
| O'Shea et al. | Reference conditions and substructuring techniques in flexible multibody system dynamics | |
| Hong et al. | Optimization of flexible components of multibody systems via equivalent static loads | |
| Di Gregorio | Kinematics of the translational 3-URC mechanism | |
| Refachinho de Campos et al. | Rigid body formulation in a finite element context with contact interaction | |
| Qiu et al. | Analysis and Synthesis of Compliant Parallel Mechanisms--screw Theory Approach | |
| Lindberg et al. | Component mode synthesis using undeformed interface coupling modes to connect soft and stiff substructures | |
| Agarwal et al. | Dynamics of serial kinematic chains with large number of degrees-of-freedom | |
| Khalil et al. | General dynamic algorithm for floating base tree structure robots with flexible joints and links | |
| Udai et al. | Dynamic simulation of a KUKA KR5 industrial robot using MATLAB SimMechanics | |
| Vidoni et al. | 3-D ERLS based dynamic formulation for flexible-link robots: theoretical and numerical comparison between the finite element method and the component mode synthesis approaches | |
| CN108393928B (en) | Multi-rigid-finite-element hybrid analysis method for contact collision of mechanical arm of flexible robot | |
| CN113524174B (en) | Mechanical arm digital twin model construction method, system, device and storage medium | |
| Arsenault et al. | Kinematic, static, and dynamic analysis of a spatial three-degree-of-freedom tensegrity mechanism | |
| Ma et al. | Elasto-dynamic performance evaluation of a 6-DOF hybrid polishing robot based on kinematic modeling and CAE technology | |
| Bowling et al. | Reliability-based design optimization of robotic system dynamic performance | |
| Gasparetto | On the modeling of flexible-link planar mechanisms: experimental validation of an accurate dynamic model | |
| Tigue et al. | Simultaneous kinematic and contact force modeling of a human finger tendon system using bond graphs and robotic validation | |
| Luo et al. | Rigid-flexible coupling dynamics simulation of 3-RPS parallel robot based on ADAMS and ANSYS | |
| Luo et al. | Rigid-flexible coupling dynamics analysis of a spot-welding robot | |
| Collard et al. | Optimal synthesis of a planar reactionless three-degree-of-freedom parallel mechanism | |
| CN107220459B (en) | Finite element analysis method for push rod of bulldozer | |
| Gmiterko et al. | Analysis of air-spring for a link of hyper-redundant manipulator |
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 | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20210429 Address after: 211135 No.26, Xicun shooting range Central Road, Qilin street, Jiangning District, Nanjing City, Jiangsu Province Patentee after: Nanjing jianweitai automation equipment Co.,Ltd. Address before: 210094 Xuanwu District, Jiangsu, Xiaolingwei 200, Nanjing Patentee before: NANJING University OF SCIENCE AND TECHNOLOGY |
|
| TR01 | Transfer of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20200630 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |