CN106681269A - Cutted thread processing method based on dynamic moving average step number - Google Patents

Cutted thread processing method based on dynamic moving average step number Download PDF

Info

Publication number
CN106681269A
CN106681269A CN201510745458.4A CN201510745458A CN106681269A CN 106681269 A CN106681269 A CN 106681269A CN 201510745458 A CN201510745458 A CN 201510745458A CN 106681269 A CN106681269 A CN 106681269A
Authority
CN
China
Prior art keywords
dynamic
spindle
step number
interpolation cycle
dynamic mobile
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.)
Granted
Application number
CN201510745458.4A
Other languages
Chinese (zh)
Other versions
CN106681269B (en
Inventor
刘荫忠
樊丙建
孙维堂
黄冠
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.)
Liaocheng Lusheng Numerical Control Machinery Co Ltd
Shenyang Institute of Computing Technology of CAS
Original Assignee
Liaocheng Lusheng Numerical Control Machinery Co Ltd
Shenyang Institute of Computing Technology of CAS
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 Liaocheng Lusheng Numerical Control Machinery Co Ltd, Shenyang Institute of Computing Technology of CAS filed Critical Liaocheng Lusheng Numerical Control Machinery Co Ltd
Priority to CN201510745458.4A priority Critical patent/CN106681269B/en
Publication of CN106681269A publication Critical patent/CN106681269A/en
Application granted granted Critical
Publication of CN106681269B publication Critical patent/CN106681269B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B19/00—Programme-control systems
    • G05B19/02—Programme-control systems electric
    • G05B19/18—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form
    • G05B19/182—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form characterised by the machine tool function, e.g. thread cutting, cam making, tool direction control
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B19/00—Programme-control systems
    • G05B19/02—Programme-control systems electric
    • G05B19/18—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form
    • G05B19/404—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form characterised by control arrangements for compensation, e.g. for backlash, overshoot, tool offset, tool wear, temperature, machine construction errors, load, inertia
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B2219/00—Program-control systems
    • G05B2219/30—Nc systems
    • G05B2219/45—Nc applications
    • G05B2219/45136—Turning, lathe
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B2219/00—Program-control systems
    • G05B2219/30—Nc systems
    • G05B2219/45—Nc applications
    • G05B2219/45203—Screwing

Landscapes

  • Engineering & Computer Science (AREA)
  • Human Computer Interaction (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Numerical Control (AREA)

Abstract

The invention relates to the field of numerical control machine tool control and particularly relates to a cutted thread processing method based on dynamic moving average step number for numerically controlled lathe thread processing. According to a spindle encoder resolution which is a spindle pulse number per revolution and a set allowable spindle rotation number feedback dynamic error, through a thread processing instruction and a given spindle rotation speed, a dynamic moving average step number is obtained, a spindle rotation number is dynamically calculated according to cycle interpolation counting, the spindle rotation speed feedback jitter caused by spindle encoder low resolution is reduced, spindle accumulated rotation number correctness is satisfied, the thread processing precision is improved, and the method is suitable for all digital controlled lathe control systems with support of cutted thread processing.

Description

A kind of cutted thread processing method average based on dynamic mobile
Technical field
The present invention relates to Digit Control Machine Tool control field, specifically for a kind of turning spiral shell of numerically controlled lathe Pattern processing method.
Background technology
Current numerically controlled lathe be quantity it is extremely huge, using extremely wide Digit Control Machine Tool.Screw thread process is car One of typical processing mode of bed, economical, popular lathe is the most universal, and lathe manufacturer is in order to control This is made, the relatively low rotation of resolution generally can be selected in the type selecting of main spindle's sensory feedback device Encoder, for realization rotate into processing can be met in mode to, main shaft orientation, uniformly linear cutting etc. will Ask.And for cutted thread aspect, it is not high that the numerical control control method being usually used can only meet required precision Screw thread process, especially precision more declines in the case of workpiece spindle (main shaft) slow-speed of revolution, due to machine tool mechanical Characteristic and workpiece technological requirement, cause the speed of mainshaft during screw thread process to arrange too high；Main shaft If position sensing feedback device selects high-resolution rotary encoder, the increase of lathe cost can be brought again, it is right For the numerically controlled lathe of relative low price, lathe manufacturer will not generally purchase high resolution encoder to be used for On economical and popular numerically controlled lathe.
With developing rapidly for modern manufacturing industry, machine tool structure is also constantly changing, such as occur in that each Class tooth machining unit, rib machine etc..But it is after all simple function thread generator, using CNC Lathe Turning screw thread Remain the means being widely used.Numerically controlled lathe tradition turning screw method, due to main shaft resolution it is low, In workpiece spindle rotation process, each planning interpolation cycle threading tool feeds with main axis position, It is uneven that feed shaft follows the amount of feeding, and certain impact is caused on accuracy of screw machining.
The content of the invention
For the deficiency that existing cutted thread method is present, it is an object of the invention to provide a kind of based on dynamic shifting Dynamic average cutted thread processing method.Based on the method, the present invention can improve CNC Lathe Turning screw thread and add Work precision, it is ensured that feed shaft follows speed steady, and thread pitch is uniform.
The present invention is applied to economical, the popular and most of numerically controlled lathe control for possessing cutted thread processing System, it is adaptable to one start screw, multiple thread processing, it is adaptable to which straight thread, oblique screw thread, end-face helical add Work.
The technical scheme that adopted for achieving the above object of the present invention is：A kind of car average based on dynamic mobile Screw thread process method is cut, is comprised the following steps：
Step 1：Setting allows main axis revolution to feed back dynamic error ratio；
Step 2：Instructed according to screw thread process, draw the average step number of dynamic mobile；
Step 3：By the average step number of dynamic mobile, again dynamic calculation show that the main shaft of each interpolation cycle turns Dynamic revolution；
Step 4：The main axis revolution according to obtained by each interpolation cycle dynamic calculation, and thread pitch, obtain Go out feed shaft and follow displacement.
The permission main axis revolution feeds back dynamic error ratio, refers to each interpolation cycle spindle encoder Feedback pulse counts the allowable error ratio value for calculating gained revolution, by digital control system parameter setting.
Average step number n of the dynamic mobile is to turn umber of pulse, interpolation cycle, permission according to spindle encoder is every Main axis revolution feeds back the speed of mainshaft given in dynamic error ratio, and screw thread process instruction and calculates institute , computing formula is as follows：
Wherein PrTurn umber of pulse for spindle encoder is every, S is the speed of mainshaft during screw thread process, and Δ t is Interpolation cycle, EpTo allow main axis revolution to feed back dynamic error ratio.
Again the dynamic calculation draws the main axis revolution K of each interpolation cyclei, it is according to axial coding Device periodic feedback umber of pulse, is counted by the average step number of dynamic mobile and interpolation cycle, flat by dynamic mobile Algorithm calculates gained, and computing formula is as follows：
When average step number n of dynamic mobile is 1：
Ki=ki
When average step number n of dynamic mobile is 2：
When average step number n of dynamic mobile>When 2：
WhereiniFor interpolation cycle counting, start counting up from screw thread process instruction execution；kiFor each interpolation cycle Gained spindle revolutions are calculated according to spindle encoder feedback, computing formula is as follows：
Wherein Δ SPiFor spindle encoder periodic feedback umber of pulse, PrTurn umber of pulse for spindle encoder is every.
The present invention has advantages below：
1. strong adaptability.Every Digit Control Machine Tool for supporting cutted thread to process, can adopt the side of the present invention Method.
2. accuracy of screw machining is high.Traditional turning Screw thread process method, generally only according to each interpolation cycle master Shaft counter calculates feed shaft and follows displacement, due to the restriction of spindle encoder resolution, follows displacement to shake It is larger, and the inventive method is adopted, can substantially reduce following displacement to shake, and then improve machining accuracy.
3. computation complexity is low, easily realizes.Generally control system of numerically-controlllathe lathe is not using the process that performance is high Core, the inventive method will not additionally increase control system resource, it is not necessary to the higher control system of performance, Meanwhile, method is uncomplicated, can use in CNC system for lathe.
4. support that screw thread process species is wide.The present invention can support straight thread, oblique screw thread, end-face helical processing, It is same to support one start screw, multiple thread processing, do not limited by screw thread species.
5. numerically controlled lathe cost can be reduced.The screw thread of processing request high precision, generally need to be from high-grade numerical control lathe Bed, a topmost part is exactly high-resolution spindle encoder；And the inventive method is adopted, using general Logical encoder can equally process high precision screw, still reach in the case where lathe cost is not improved Processing progress, from this view can reduces cost.
One kind of the present invention be directed to spindle encoder resolution it is low and can meet feed shaft each planning interpolation week Phase follows the amount of feeding as far as possible uniform, and and can guarantee that and follow the correct Screw thread process method in position, improve car Cut accuracy of thread.
Description of the drawings
Fig. 1 is the inventive method flow chart；
Fig. 2 be using the inventive method before and after workpiece spindle each cycle rotate revolution comparison diagram；
Fig. 3 be using the inventive method before and after feed shaft follow velocity contrast to scheme；
Fig. 4 be using the inventive method before and after feed shaft acceleration of motion comparison diagram.
Specific embodiment
Below in conjunction with the accompanying drawings and embodiment the present invention is described in further detail.
Setting first allows main axis revolution to feed back dynamic error ratio；Given according to screw thread process instruction The speed of mainshaft, draws the average step number of dynamic mobile；Find spindle encoder zero point and latch position；Through screw thread Main shaft original position required by machining starting point, starts screw thread process；
The main axis revolution of current interpolation cycle is calculated according to spindle encoder feedback count；By dynamic shifting Average step number is moved, again dynamic calculation draws the main axis revolution of current interpolation cycle；According to current interpolation Cycle dynamic calculation gained main axis revolution, and thread pitch, show that feed shaft follows moving displacement； Machined reach is calculated, judges whether to machine, it is unfinished then wait next interpolation cycle to continue, Otherwise complete processing.
Referring to Fig. 1, the flow process of dynamic mobile averaging method of the present invention is described.
The permission main axis revolution feeds back dynamic error ratio, refers to each interpolation cycle spindle encoder Feedback pulse counts the allowable error ratio value for calculating gained revolution, by digital control system parameter setting.This ginseng Number is less, and the average step Numerical of dynamic mobile is bigger, and feed shaft follows velocity variations less.
Average step number n of the dynamic mobile is to turn umber of pulse, interpolation cycle, permission according to spindle encoder is every Main axis revolution feeds back speed of mainshaft S given in dynamic error, and screw thread process instruction and calculates gained, The average step number of this dynamic mobile is the important evidence of the inventive method, and computing formula is as follows：
Wherein PrTurn umber of pulse for spindle encoder is every, S is the speed of mainshaft during screw thread process, and Δ t is Interpolation cycle, EpTo allow main axis revolution to feed back dynamic error ratio.
Can be seen that spindle encoder is every to turn that the less i.e. resolution of umber of pulse is lower, main shaft turns according to this formula Fast less, interpolation cycle is shorter, and the average step Numerical of dynamic mobile is bigger, and by the way that setting is suitable main shaft is allowed Revolution feedback dynamic error ratio is rotated, the average step number of dynamic mobile is drawn, feed shaft is reduced and is followed speed to become Change.
The spindle encoder zero point latches position, refers to main shaft per turning have a fixed position to be embodied in master On shaft encoder, encoder to count is latched by finding this position, can be accurately to main shaft orientation.
Main shaft original position required by the screw thread process starting point, to refer to and process what is needed for multiple thread Main shaft deviation angle in fact.
The main axis revolution of the current interpolation cycle, computing formula is as follows：
Wherein i is interpolation cycle counting, starts counting up from screw thread process instruction execution, PrIt is every for spindle encoder Turn umber of pulse, Δ SPiFor spindle encoder periodic feedback umber of pulse, kiTo calculate gained spindle revolutions.
Again the dynamic calculation draws the main axis revolution K of each interpolation cycleiIt is according to spindle encoder Periodic feedback umber of pulse, is counted by the average step number of dynamic mobile and interpolation cycle, average by dynamic mobile Algorithm calculates gained, it is key that the inventive method is achieved, computing formula is as follows：
When average step number n of dynamic mobile is 1, representing need not adopt dynamic mobile averaging method, meet Accuracy of screw machining is required：
Ki=ki
When average step number n of dynamic mobile is 2：
When average step number n of dynamic mobile>When 2：
Wherein i is interpolation cycle counting, starts counting up from screw thread process instruction execution；kiFor each interpolation cycle Gained spindle revolutions are calculated according to spindle encoder feedback.
Referring to Fig. 2, describe to use main shaft (i.e. workpiece spindle) each cycle before and after the inventive method to rotate revolution Contrast situation, it can be seen that the actual speed fluctuation of main shaft is obviously reduced, closer to practical situation.
According to formula as can be seen that not being affected using the accumulative revolution of main shaft after dynamic mobile averaging method, I.e.：
The feed shaft follows moving displacement, the amount of feeding for needed for current interpolation cycle feed shaft, computing formula It is as follows：
ΔLi=Ki×Pitch
Referring to Fig. 3, the feed shaft before and after describing using the inventive method follows velocity contrast's situation, trend with It is completely the same shown in Fig. 2；Referring to Fig. 4, describe to use the feed shaft acceleration of motion before and after the inventive method Contrast situation, it can be seen that feed shaft velocity variations are substantially reduced.
The machined reach, refers to feed shaft moving displacement, and computing formula is as follows：
It is described to judge whether to machine, refer to whether machined reach has reached screw thread process instruction institute The reach of requirement, condition criterion is as follows：
Li＞ L
Wherein L is the required reach of screw thread process instruction.

Claims (4)

1. a kind of cutted thread processing method average based on dynamic mobile, it is characterised in that comprise the following steps：
Step 1：Setting allows main axis revolution to feed back dynamic error ratio；
Step 2：Instructed according to screw thread process, draw the average step number of dynamic mobile；
Step 3：By the average step number of dynamic mobile, again dynamic calculation show that the main shaft of each interpolation cycle turns Dynamic revolution；
Step 4：The main axis revolution according to obtained by each interpolation cycle dynamic calculation, and thread pitch, obtain Go out feed shaft and follow displacement.
2. a kind of cutted thread processing method average based on dynamic mobile according to claim 1, its feature It is that the permission main axis revolution feeds back dynamic error ratio, refers to each interpolation cycle axial coding Device feedback pulse counts the allowable error ratio value for calculating gained revolution, by digital control system parameter setting.
3. a kind of cutted thread processing method average based on dynamic mobile according to claim 1, its feature It is that average step number n of the dynamic mobile is to turn umber of pulse, interpolation cycle, permit according to spindle encoder is every Perhaps the speed of mainshaft given in the instruction of main axis revolution feedback dynamic error ratio, and screw thread process is calculated Gained, computing formula is as follows：
Wherein PrTurn umber of pulse for spindle encoder is every, S is the speed of mainshaft during screw thread process, and Δ t is Interpolation cycle, EpTo allow main axis revolution to feed back dynamic error ratio.
4. a kind of cutted thread processing method average based on dynamic mobile according to claim 1, its feature It is that the dynamic calculation again draws the main axis revolution K of each interpolation cyclei, it is to be compiled according to main shaft Code device periodic feedback umber of pulse, is counted, by dynamic mobile by the average step number of dynamic mobile and interpolation cycle Average algorithm calculates gained, and computing formula is as follows：
When average step number n of dynamic mobile is 1：
Ki=ki
When average step number n of dynamic mobile is 2：
When average step number n of dynamic mobile>When 2：
WhereiniFor interpolation cycle counting, start counting up from screw thread process instruction execution；kiFor each interpolation cycle Gained spindle revolutions are calculated according to spindle encoder feedback, computing formula is as follows：
k i = ΔSP i P r
Wherein Δ SPiFor spindle encoder periodic feedback umber of pulse, PrTurn umber of pulse for spindle encoder is every.
CN201510745458.4A 2015-11-05 2015-11-05 A kind of cutted thread processing method average based on dynamic mobile Active CN106681269B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201510745458.4A CN106681269B (en) 2015-11-05 2015-11-05 A kind of cutted thread processing method average based on dynamic mobile

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201510745458.4A CN106681269B (en) 2015-11-05 2015-11-05 A kind of cutted thread processing method average based on dynamic mobile

Publications (2)

Publication Number Publication Date
CN106681269A true CN106681269A (en) 2017-05-17
CN106681269B CN106681269B (en) 2018-11-27

Family

ID=58857335

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201510745458.4A Active CN106681269B (en) 2015-11-05 2015-11-05 A kind of cutted thread processing method average based on dynamic mobile

Country Status (1)

Country Link
CN (1) CN106681269B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111857040A (en) * 2020-07-15 2020-10-30 清华大学 Main shaft following synchronous control method for improving thread turning precision
CN113676091A (en) * 2021-09-01 2021-11-19 珠海格力智能装备有限公司 Motor driving method and device and motion control system
CN117092966A (en) * 2023-10-16 2023-11-21 中山迈雷特数控技术有限公司 Control method for thread processing based on EtherCAT bus

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1418758A (en) * 2002-12-20 2003-05-21 南京师范大学 Working method of linear cutting high precision double plane runin different plane
CN1647881A (en) * 2004-01-30 2005-08-03 发那科株式会社 Threading/tapping control apparatus
EP2033726A1 (en) * 2007-09-10 2009-03-11 HANWHA TECH M Co., Ltd. Automatic lathe
CN101853013A (en) * 2009-04-01 2010-10-06 中国科学院沈阳计算技术研究所有限公司 Acceleration and deceleration control method for high speed machining of numerical control machine
CN102789204A (en) * 2011-05-20 2012-11-21 沈阳机床(集团)设计研究院有限公司上海分公司 High-speed thread interpolation method for economic numerical control lathe
CN103713580A (en) * 2013-12-31 2014-04-09 深圳市配天数控科技有限公司 Numerical control system and feed-forward control method for shaft movement thereof

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1418758A (en) * 2002-12-20 2003-05-21 南京师范大学 Working method of linear cutting high precision double plane runin different plane
CN1647881A (en) * 2004-01-30 2005-08-03 发那科株式会社 Threading/tapping control apparatus
EP2033726A1 (en) * 2007-09-10 2009-03-11 HANWHA TECH M Co., Ltd. Automatic lathe
CN101853013A (en) * 2009-04-01 2010-10-06 中国科学院沈阳计算技术研究所有限公司 Acceleration and deceleration control method for high speed machining of numerical control machine
CN102789204A (en) * 2011-05-20 2012-11-21 沈阳机床(集团)设计研究院有限公司上海分公司 High-speed thread interpolation method for economic numerical control lathe
CN103713580A (en) * 2013-12-31 2014-04-09 深圳市配天数控科技有限公司 Numerical control system and feed-forward control method for shaft movement thereof

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111857040A (en) * 2020-07-15 2020-10-30 清华大学 Main shaft following synchronous control method for improving thread turning precision
CN111857040B (en) * 2020-07-15 2021-10-08 清华大学 Main shaft following synchronous control method for improving thread turning precision
CN113676091A (en) * 2021-09-01 2021-11-19 珠海格力智能装备有限公司 Motor driving method and device and motion control system
CN113676091B (en) * 2021-09-01 2024-04-16 珠海格力智能装备有限公司 Motor driving method, motor driving device and motor motion control system
CN117092966A (en) * 2023-10-16 2023-11-21 中山迈雷特数控技术有限公司 Control method for thread processing based on EtherCAT bus
CN117092966B (en) * 2023-10-16 2024-01-02 中山迈雷特数控技术有限公司 Control method for thread processing based on EtherCAT bus

Also Published As

Publication number Publication date
CN106681269B (en) 2018-11-27

Similar Documents

Publication Publication Date Title
US4033206A (en) Numerically controlled machine tool
US4580225A (en) Method for producing multiple entry threads
CN103123477B (en) Shaft motion control method based on double feedbacks of motor and machine tool location
CN101879636B (en) Method for machining a fence drum rope groove by using numerical control machine
CN106681269A (en) Cutted thread processing method based on dynamic moving average step number
CN103809520B (en) Full closed-loop control method for multi-shaft linked dynamic correction of interpolation positions
CN101332524A (en) Numerical control generating gear grinding machine and numerical control device thereof and driving method
GB2178199A (en) Machine tool control systems
GB1596453A (en) Grinding workpieces
CN100411792C (en) Threading control method and controller
CN107615195B (en) Method for tapping threaded hole, numerical control machine tool and numerical control machining device
CN102806494B (en) Rotation angle location device
US3817129A (en) Numerically controlled threadcutting system
CN101323035A (en) Digital control continuous finishing method of large pitch ball screw nut
CN111007803B (en) Numerical control code standardized integrated model and method for machining process
US6628097B2 (en) Machine tool and control method therefor
Guo et al. A rapid and accurate positioning method with linear deceleration in servo system
JP2005202844A (en) Numerical controller
KR101336520B1 (en) Apparatus for processing serew and controlling method thereof
CN111857040B (en) Main shaft following synchronous control method for improving thread turning precision
US6658317B2 (en) Method for setting a moving position in a machine tool
JP5887987B2 (en) Gear machining method and NC data creation device
US4266170A (en) Safety arrangement for NC systems
JP2001228909A (en) Machine tool and its control method
KR102067843B1 (en) Feed drive system thermal deformation correction device of machine tool and method thereof

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