CN112050724A - Deformation detection device and deformation detection method for building structure - Google Patents
Deformation detection device and deformation detection method for building structure Download PDFInfo
- Publication number
- CN112050724A CN112050724A CN202010776129.7A CN202010776129A CN112050724A CN 112050724 A CN112050724 A CN 112050724A CN 202010776129 A CN202010776129 A CN 202010776129A CN 112050724 A CN112050724 A CN 112050724A
- Authority
- CN
- China
- Prior art keywords
- deformation
- building structure
- resistance
- strain gauge
- controller
- 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.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/16—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge
- G01B7/18—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge using change in resistance
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
Abstract
The invention provides a deformation detection device and a deformation detection method for a building structure, wherein the deformation detection device comprises a box body and a plurality of sensors, the sensors are distributed on the transverse direction and the longitudinal direction of the building structure to be detected, a controller and a display nixie tube are arranged in the box body, the sensors are connected with an A/D pin of the controller through an operational amplification circuit, one side of the box body is an operation panel, a display screen, a switch button and an indicator light are arranged on the operation panel, the display nixie tube is electrically connected with the controller and arranged on the inner side of the display screen, and the transverse deformation and the longitudinal deformation of the building structure to be detected are displayed on the display screen. The device can measure the shape variable of the building structures such as bridges, houses, tunnels and the like, can be used in laboratories or fields, can be used for workers to accurately measure the shape variable of the building structures such as bridges, houses, tunnels and the like very conveniently, and has the advantages of high measurement accuracy, convenient reading and no need of secondary calculation on the result.
Description
Technical Field
The invention relates to the field of deformation detection of building structures, in particular to a device and a method for detecting deformation of a building structure.
Background
Because the deformation of the building structure is generated by dynamic accumulation and has uncertainty on the time and the deformation amount of the deformation, the traditional monitoring instrument and method are not easy to find, and the current building industry determines the deformation of the building structure such as bridges, houses, tunnels and the like by a professional detection instrument, and the defects and disadvantages are that: the monitoring precision is limited by technical parameters of purchased instruments, the deformation is usually delayed in manual field monitoring, the deformation perception degree is low in real-time monitoring, and the most important problem is that the real-time monitoring cannot be carried out in underground engineering or places with weak satellite signals.
Disclosure of Invention
The invention aims to provide a deformation detection device and a deformation detection method for a building structure, which can acquire the deformation of the building structures such as bridges, houses and tunnels in real time and high precision, and the deformation value is dynamically displayed in real time through a nixie tube.
In order to solve the technical problem, an embodiment of the present invention provides a building structure deformation detection device, which includes a box body and a plurality of sensors, wherein the plurality of sensors are distributed in the transverse direction and the longitudinal direction of the characteristic sensitive point position of a building structure to be detected, a controller and a display nixie tube are arranged in the box body, the plurality of sensors are connected with an a/D pin of the controller through an operational amplification circuit, one side of the box body is an operation panel, a display screen, a switch button and an indicator light are arranged on the operation panel, the display nixie tube is electrically connected with the controller and is arranged on the inner side of the display screen, and the transverse deformation amount and the longitudinal deformation amount of the building structure to be detected are displayed on the display screen.
The side of the box body is provided with a plurality of wiring terminals, the sensors are connected with the wiring terminals in a one-to-one correspondence mode, and the wiring terminals are correspondingly connected with A/D pins of the controller through the operational amplification circuit.
Wherein, a power supply for supplying power to the operational amplification circuit and the controller is arranged in the box body.
Preferably, the power supply voltage of the power supply is 5V.
Preferably, the sensor is a BX120-50AA resistance strain gauge. The controller selects an STM32F103ZET6 chip of a 32-bit machine.
The sensor is adhered to the building structure to be detected through an adhesive, and the adhesive has electric insulation.
Wherein, be equipped with deformation early warning and transfinite buzzer siren in the box body.
The indicating lamps comprise a reset indicating lamp, a zero clearing indicating lamp, a calibration indicating lamp and a display maintaining indicating lamp.
The invention also provides a deformation detection method using the building structure deformation detection device, which comprises the following steps:
(1) the resistance strain gauge is adhered or fixed to the position of the characteristic point of the building structure to be detected, when the structure is deformed, the resistance strain gauge deforms along with the building structure to be detected, resistance of a resistance wire in the resistance strain gauge is changed due to mechanical deformation of the resistance wire, and the change of the resistance can reflect the deformation condition of the building structure to be detected;
the sticking requirement of the resistance strain gauge is as follows:
(1-1) carefully checking and sorting the resistance strain gauges to ensure the quality of the resistance strain gauges; meanwhile, the measuring points are transversely and longitudinally arranged at characteristic measuring points capable of reflecting the deformation of the building structure to be detected;
(1-2) flattening, cleaning and drying the measuring point substrate, so that the resistance strain gauge can be firmly adhered or fixed to the characteristic point of the building structure to be detected without falling off, warping and containing no bubbles;
(1-3) insulating the resistance strain gauge from a test piece by using the adhesive, and ensuring the stability of the resistance value of the resistance strain gauge without creep deformation;
(1-4) the pasting direction and position must be accurate;
(2) the controller receives the deformation signals of the resistance strain gauges and calculates the longitudinal deformation and the transverse deformation of the structure according to the resistance variation;
(3) the transverse deformation and the longitudinal deformation of the building structure to be detected are displayed on the display screen.
The technical scheme of the invention has the following beneficial effects: the system can measure the shape variable of the building structures such as bridges, houses, tunnels and the like, can be used in laboratories or in the field, can be used for conveniently and dynamically and accurately measuring the shape variable of the building structures such as bridges, houses, tunnels and the like in real time by workers, has high measurement precision, is convenient to read, does not need secondary calculation as a result, integrates communication, network sensing and deformation analysis and calculation, can be used for detecting and evaluating the deformation state of the building structures, and is an economical and efficient structure health detection system.
Drawings
FIG. 1 is a schematic structural view of the present invention;
FIG. 2 is a schematic structural view of the inner side of the case body according to the present invention;
FIG. 3 is a block circuit diagram of the present invention;
fig. 4 is a flow chart of the operation of the present invention.
Description of reference numerals:
1. a box body; 2. a sensor; 4. a controller; 5. displaying the nixie tube; 6. an operation panel; 61. a display screen; 62. a switch button; 63. an indicator light; 7. a wiring terminal; 8. a power source; 9. a buzzer alarm.
Detailed Description
In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings and specific embodiments.
As shown in fig. 1 and 2, an embodiment of the present invention provides a building structure deformation detection apparatus, including a box 1 and a plurality of sensors 2, the plurality of sensors 2 are distributed in the transverse direction and the longitudinal direction of a building structure feature detection point to be detected, a controller 4 and a display nixie tube 5 are arranged in the box 1, the plurality of sensors 2 are connected with an a/D pin of the controller 4 through an operational amplifier circuit, one side of the box 1 is an operation panel 6, the operation panel 6 is provided with a display screen 61, a switch button 62 and an indicator light 63, and the indicator light 63 includes a reset indicator light, a clear indicator light, a calibration indicator light and a display maintenance indicator light.
The display nixie tube 5 is electrically connected with the controller 4 and is arranged on the inner side of the display screen 61, and the transverse deformation and the longitudinal deformation of the building structure to be detected are displayed on the display screen 61.
A buzzer alarm 9 is further arranged in the box body 1, and an occurrence opening of the buzzer alarm 9 is arranged on the operation panel 6.
The side of box body 1 is equipped with a plurality of binding post 7, and is a plurality of sensor 2 is connected with a plurality of binding post 7 one-to-one, binding post 7 corresponds with the AD pin of controller 4 through operational amplifier circuit and is connected.
The box body 1 is internally provided with a power supply 8 for supplying power to the operational amplification circuit and the controller 4. The power supply voltage of the power supply 8 is 5V.
The sensor 2 adopts a BX120-50AA resistance strain gauge.
The controller 4 selects an STM32F103ZET6 chip of a 32-bit machine.
The sensor 2 is adhered to the building structure to be detected through an adhesive, and the adhesive is good in electrical insulation and stable in chemical property.
The technical solution of the present invention is described in detail below.
1. Sensor selection for deformation measuring device
The sensor of the measuring device uses a BX120-50AA resistance strain gauge, and can be used for measuring the deformation of building structures such as bridges, houses, tunnels and the like. The sensitive part of the sensor is a cantilever beam structure or a characteristic point (a tunnel top point, a tunnel bottom point, a pair of convergence points at two waists and points at two sides of a crack) on one section of the shield subway tunnel, and the nonlinear error is less than 0.5 percent within the range of +/-1 g of corresponding linear acceleration. The installation mode is gluing, and the use is very convenient. The BX120-50AA strain gauge is an analog sensor and can be directly connected with an analog I/O port of an stm32f103 series single chip microcomputer for use. Parameters of the BX120-50AA strain gage sensor are as follows.
(1) Sensitivity coefficient: 2.0 +/-1%
(2) Working temperature: minus 10 to plus 60 DEG C
(3) Operating Voltage (VDC): + 3- +10V
(4) Resistance value: 120 +/-1 ohm
(5) Base material: constantan.
2. Controller and display device selection and design for deformation measuring device
The controller of the deformation measuring device selects a common 32-bit machine STM32F103ZET6 on the market, and the display part selects a nixie tube to display the transverse and longitudinal structural deformation values. The sensor signal is connected with the A/D pin of the STM32F103ZET6 after being amplified by the operational amplifier circuit. The display nixie tube can effectively overcome the crosstalk when not gating, so that the static characteristic of display is irrelevant to scanning, and the stability of display is greatly improved. The STM32F103 chip used in the design of the measuring device is provided with the FSMC interface, so that the access speed of the measured value is greatly improved, and the real-time property and the memory of the measured value are enhanced.
3. Hardware circuit design and function description of deformation measuring device
The block diagram of the deformation measuring device is shown in fig. 3, and the sensor of the circuit is composed of 14 groups of resistance strain gauges which are required to be respectively arranged in the transverse direction and the longitudinal direction of the structure. Generally, the more the resistive strain gauge is arranged, the closer the deformation value obtained is to the true value. The multi-channel signal amplifying circuit converts the resistance variation of the resistance strain gauge into an amplified voltage signal, and because 14 groups of resistance strain gauges exist, the multi-channel signal amplifying circuit outputs 14 groups of analog signals. The signals are directly sent to the single chip microcomputer, and the selected single chip microcomputer is internally provided with 16 groups of A/D conversion modules, so that the single chip microcomputer can directly process the signals without an additional A/D conversion module. The power supply unit of the deformation measuring device is powered by 5V, a power adapter of a mobile phone is usually used, the measured deformation value is in mm, and the deformation of the building structure to be measured is displayed by the transverse deformation value and the longitudinal deformation value.
4. Implementation of deformation measurement
When the resistance strain gauge is used for measuring strain, the strain gauge is adhered to a detection point of a building structure to be detected, when the structure deforms, the resistance strain gauge deforms along with the structure, the resistance of the resistance wire changes due to mechanical deformation of the resistance wire in the resistance strain gauge, and the change of the resistance reflects the deformation condition of the detection point of the structure, which is the basic principle of measuring strain by using the resistance strain gauge. Strain gage resistance changes are caused by mechanical deformation of the metal,
the invention is realized by arranging a plurality of resistance strain gauges in the transverse direction and the longitudinal direction of a structure, when the detection point of the structure is slightly deformed, the resistance strain gauges are inevitably deformed, the deformation of the detection point of the structure is in direct proportion to the deformation of the strain gauges, and the deformation result of the strain gauges directly causes the resistance value change of a resistor. When the transverse stretching (compression) of the detection point of the structure changes, the resistance of the transversely arranged strain gauge can be increased (reduced), and the transverse deformation of the structure is calculated by a certain algorithm according to the increase (reduction) of the resistance. When the longitudinal stretching (compression) of the detection point of the structure changes, the resistance of the longitudinally arranged strain gauge can be increased (reduced), and the longitudinal deformation of the structure is calculated by a certain algorithm according to the increase (reduction) of the resistance.
5. Deformation measuring device sensor mounting
When the resistance strain gauge is arranged on the structure: firstly, the strain gauge and the detected point are required to be deformed together, and secondly, the resistance value of the resistance strain gauge is required to be stable, so that an accurate strain measurement result can be obtained, which is the basic principle of strain gauge pasting. Therefore, the quality of the strain gauge itself and the quality of the adhesion have a great influence on the measurement result, and the strain gauge must be firmly adhered to the detected point of the test piece, so that the technical requirement on the adhesion is very strict. In order to ensure the pasting quality and the measurement accuracy, the following requirements are required:
(1) carefully checking and sorting the resistance strain gauges to ensure the quality of the strain gauges; both laterally and longitudinally at the structure measurement points.
(2) The measuring point substrate is flat, clean and dry, so that the strain gauge can be firmly pasted on a test piece, does not fall off or warp, and does not contain bubbles;
(3) the adhesive has good electrical insulation, stable chemical property, good process performance, small creep, high bonding strength and small influence of temperature and humidity, ensures the bonding quality, insulates the strain gauge from a test piece, does not creep, and ensures the stability of the resistance value of the resistance strain gauge;
(4) the direction and position of the sticking must be correct because the deformation is different at different positions and different directions on the test piece.
6. Deformation measurement device software design
The programming flow chart of the detection device provided by the invention is shown in fig. 4.
7. The outline of the detection device provided by the invention is shown in figure 1.
While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (10)
1. The utility model provides a building structure thing becomes detection device, its characterized in that, includes box body and a plurality of sensor, and is a plurality of the sensor distributes in the horizontal and vertical of waiting to detect building structure characteristic sensitive point position, be provided with controller and demonstration charactron in the box body, it is a plurality of the sensor passes through the operation amplifier circuit and is connected with the AD pin of controller, one side of box body is operating panel, operating panel is last to be equipped with display screen, shift knob and pilot lamp, show charactron and controller electric connection and locate the inboard of display screen, wait to detect the horizontal deflection and the vertical deflection of building structure and show on the display screen.
2. The building structure shape change detection device according to claim 1, wherein a plurality of connection terminals are provided on a side of the box body, the plurality of sensors are connected to the plurality of connection terminals in a one-to-one correspondence, and the connection terminals are connected to a/D pins of the controller through an operational amplifier circuit.
3. The building structure shape change detecting apparatus according to claim 1, wherein a power supply for supplying power to the operational amplifier circuit and the controller is provided in the box body.
4. A deformation sensing device for building structures according to claim 3, characterized in that the power supply voltage of said power supply is 5V.
5. The building structure form factor detection device of claim 1, wherein the sensor is a BX120-50AA resistance strain gauge.
6. The building structure form change detecting device of claim 1 or 2, wherein the controller selects a 32 bit machine STM32F103ZET6 chip.
7. A deformation sensing device for building structures according to claim 3, characterized in that said sensor is affixed to the building structure to be sensed by means of an adhesive, said adhesive having electrical insulation properties.
8. The building structure shape change detection device according to claim 1, wherein a deformation warning and overrun buzzer alarm is provided in the box body.
9. The building structure form factor detection device of claim 1, wherein the indicator lights include a reset indicator light, a clear indicator light, a calibration indicator light, and a display hold indicator light.
10. A deformation sensing method using the building structure deformation sensing apparatus according to any one of claims 1 to 9, characterized by comprising the steps of:
(1) the resistance strain gauge is adhered or fixed to the position of the characteristic point of the building structure to be detected, when the structure is deformed, the resistance strain gauge deforms along with the building structure to be detected, resistance of a resistance wire in the resistance strain gauge is changed due to mechanical deformation of the resistance wire, and the change of the resistance can reflect the deformation condition of the building structure to be detected;
the sticking requirement of the resistance strain gauge is as follows:
(1-1) carefully checking and sorting the resistance strain gauges to ensure the quality of the resistance strain gauges; meanwhile, the measuring points are transversely and longitudinally arranged at characteristic measuring points capable of reflecting the deformation of the building structure to be detected;
(1-2) flattening, cleaning and drying the measuring point substrate, so that the resistance strain gauge can be firmly adhered or fixed to the characteristic point of the building structure to be detected without falling off, warping and containing no bubbles;
(1-3) insulating the resistance strain gauge from a test piece by using the adhesive, and ensuring the stability of the resistance value of the resistance strain gauge without creep deformation;
(1-4) the pasting direction and position must be accurate;
(2) the controller receives the deformation signals of the resistance strain gauges and calculates the longitudinal deformation and the transverse deformation of the structure according to the resistance variation;
(3) the transverse deformation and the longitudinal deformation of the building structure to be detected are displayed on the display screen.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010776129.7A CN112050724A (en) | 2020-08-05 | 2020-08-05 | Deformation detection device and deformation detection method for building structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010776129.7A CN112050724A (en) | 2020-08-05 | 2020-08-05 | Deformation detection device and deformation detection method for building structure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112050724A true CN112050724A (en) | 2020-12-08 |
Family
ID=73602299
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010776129.7A Pending CN112050724A (en) | 2020-08-05 | 2020-08-05 | Deformation detection device and deformation detection method for building structure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112050724A (en) |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1266182A (en) * | 2000-04-05 | 2000-09-13 | 深圳职业技术学院 | Method for testing working stress of buildings structure in situ |
| CN101982724A (en) * | 2010-09-21 | 2011-03-02 | 同济大学 | Online real-time monitoring method for dynamic deflection deformation of wind driven generator blade |
| CN103808248A (en) * | 2013-07-31 | 2014-05-21 | 镇江市高等专科学校 | Large-span steel structure bridge resistance strain type safety detection device |
| CN103983182A (en) * | 2014-05-27 | 2014-08-13 | 相斌辉 | Portable type strain gauge adhering technology |
| CN104748664A (en) * | 2015-03-13 | 2015-07-01 | 南华大学 | Rock-soil mass interior displacement measuring system |
| CN104820022A (en) * | 2015-04-03 | 2015-08-05 | 山东大学 | Steel pipe concrete arch frame coupling performance detection and evaluation method, and steel pipe concrete arch frame coupling performance detection structure |
| CN105203238A (en) * | 2015-10-23 | 2015-12-30 | 四川大学 | Pressure measurement and data transmission system based on MSP430 single chip microcomputer |
| CN206593589U (en) * | 2017-03-20 | 2017-10-27 | 华中科技大学 | A kind of strain transducer of visualization of presence |
| CN207798304U (en) * | 2017-09-22 | 2018-08-31 | 鞍山天翼机电科技有限公司 | A kind of strain-type rectangular sensor |
| CN108709534A (en) * | 2018-06-27 | 2018-10-26 | 中国地质大学（武汉） | Shield tunnel construction stress deformation indoor model test device and its installation method |
| CN209910581U (en) * | 2019-06-12 | 2020-01-07 | 山东东汇工程检测鉴定有限公司 | Identification device for house safety static strain |
-
2020
- 2020-08-05 CN CN202010776129.7A patent/CN112050724A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1266182A (en) * | 2000-04-05 | 2000-09-13 | 深圳职业技术学院 | Method for testing working stress of buildings structure in situ |
| CN101982724A (en) * | 2010-09-21 | 2011-03-02 | 同济大学 | Online real-time monitoring method for dynamic deflection deformation of wind driven generator blade |
| CN103808248A (en) * | 2013-07-31 | 2014-05-21 | 镇江市高等专科学校 | Large-span steel structure bridge resistance strain type safety detection device |
| CN103983182A (en) * | 2014-05-27 | 2014-08-13 | 相斌辉 | Portable type strain gauge adhering technology |
| CN104748664A (en) * | 2015-03-13 | 2015-07-01 | 南华大学 | Rock-soil mass interior displacement measuring system |
| CN104820022A (en) * | 2015-04-03 | 2015-08-05 | 山东大学 | Steel pipe concrete arch frame coupling performance detection and evaluation method, and steel pipe concrete arch frame coupling performance detection structure |
| CN105203238A (en) * | 2015-10-23 | 2015-12-30 | 四川大学 | Pressure measurement and data transmission system based on MSP430 single chip microcomputer |
| CN206593589U (en) * | 2017-03-20 | 2017-10-27 | 华中科技大学 | A kind of strain transducer of visualization of presence |
| CN207798304U (en) * | 2017-09-22 | 2018-08-31 | 鞍山天翼机电科技有限公司 | A kind of strain-type rectangular sensor |
| CN108709534A (en) * | 2018-06-27 | 2018-10-26 | 中国地质大学（武汉） | Shield tunnel construction stress deformation indoor model test device and its installation method |
| CN209910581U (en) * | 2019-06-12 | 2020-01-07 | 山东东汇工程检测鉴定有限公司 | Identification device for house safety static strain |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH1183420A (en) | Strain measuring module and multipoint-strain measuring system | |
| CN112325763B (en) | Inspection device and inspection method for detecting mounting quality of mounted strain gauge | |
| CN214095895U (en) | Building structure object deformation detection device | |
| CN112050724A (en) | Deformation detection device and deformation detection method for building structure | |
| CN209524930U (en) | A kind of displacement sensor for pull rope calibrating installation | |
| CN1061096A (en) | Multi-purpose quick detector for grain | |
| CN208689156U (en) | A kind of Insulation Resistance Tester calibrating installation | |
| CN213689329U (en) | Self-powered environmental corrosion monitoring system for wind power equipment | |
| CN210775338U (en) | Locomotive detection hammer | |
| CN209820655U (en) | Dynamic temperature calibration device | |
| CN112213007A (en) | Wireless monitoring method for tunnel primary support arch strain based on RFID technology | |
| CN2160111Y (en) | Portable intelligent temperature detection calibrator | |
| CN214426794U (en) | Intelligent liquid level meter | |
| KR100246737B1 (en) | Digital humidity meter | |
| CN219066124U (en) | Device for detecting multipoint height difference of touch screen | |
| CN210154996U (en) | Dust concentration measuring instrument | |
| CN109540379A (en) | A kind of pressure gauge with function of failure alarm | |
| CN219842047U (en) | Sensor static characteristic acceptance equipment | |
| CN220932226U (en) | Automatic calibrating device for soldering iron temperature tester | |
| CN212433407U (en) | Sound velocity measurement and positioning experimental instrument | |
| CN214041711U (en) | Multifunctional signal calibrator | |
| CN220153802U (en) | High-sensitivity measuring system of flexible film piezoelectric sensor | |
| CN219369023U (en) | Pressure gauge calibrating instrument | |
| CN211123032U (en) | Resistivity test system for metal wire | |
| JP2577110B2 (en) | Street accuracy measuring device and street accuracy measuring method at construction site |
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 | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20201208 |
|
| WD01 | Invention patent application deemed withdrawn after publication |