CN111352371B - Bus type capacitance sensor for laser cutting and detection system - Google Patents
Bus type capacitance sensor for laser cutting and detection system Download PDFInfo
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- CN111352371B CN111352371B CN202010187148.6A CN202010187148A CN111352371B CN 111352371 B CN111352371 B CN 111352371B CN 202010187148 A CN202010187148 A CN 202010187148A CN 111352371 B CN111352371 B CN 111352371B
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- 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
- G05B19/04—Programme control other than numerical control, i.e. in sequence controllers or logic controllers
- G05B19/042—Programme control other than numerical control, i.e. in sequence controllers or logic controllers using digital processors
- G05B19/0423—Input/output
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- G—PHYSICS
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- 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
- G05B2219/20—Pc systems
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- G05B2219/24215—Scada supervisory control and data acquisition
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Abstract
The invention discloses a bus type capacitance sensor for laser cutting, which comprises: the device comprises a signal amplification module, a signal processing module and a communication module; the signal amplification module comprises an LC oscillation circuit, a signal amplification circuit and a temperature detection module, wherein the LC oscillation circuit is used for acquiring capacitance data of the capacitor to be detected, and transmitting a capacitance data signal to the signal processing module after the capacitance data signal is processed by the signal amplification circuit; the temperature detection module is used for acquiring and processing temperature data of the capacitor to be detected and transmitting a temperature data signal to the signal processing module; the signal processing module comprises an FPGA module and a data processing module, capacitance and temperature data information is processed by the FPGA module and then input into the data processing module, and an output signal of the data processing module is transmitted to the communication module; the numerical control system can be calibrated at different temperatures, so that the sensor precision at different temperatures is ensured, and the signal measurement precision and speed are improved.
Description
Technical Field
The invention relates to a bus type capacitance sensor and a detection system for laser cutting, and belongs to the field of laser cutting.
Background
When a metal plate material is laser-cut, it is necessary to stably irradiate a workpiece to be cut with a laser focus in order to obtain a smooth cut. However, during the actual cutting process, the metal plate material itself may not be flat enough or mechanical vibration may cause the focal point of the laser to be not stably irradiated on the cut plate material, thereby affecting the quality of the cut. To ensure the cutting quality, it is first necessary to keep the nozzle of the cutting head at a constant distance from the sheet material during the cutting process, which otherwise would result in poor quality of the cut.
It is therefore necessary to design a sensor capable of accurately measuring the distance between the nozzle of the laser head and the workpiece. Most of the distance sensors used for laser cutting at home and abroad adopt the principle of capacitance measurement of micro-distance, and the distance between a nozzle of a laser head and a workpiece is calculated by measuring the capacitance of a parallel plate between the nozzle of the laser head and the workpiece. However, the products on the market have communication interfaces without unified standards, and are difficult to access a numerical control system or an industrial personal computer; the sensor has lower resolution and can not reach the precision when being applied to three-dimensional laser cutting; the environment temperature changes violently in the industrial environment, if the working environment temperature of the sensor changes, the sensor needs to be recalibrated, otherwise the measurement accuracy of the sensor is affected, and the like.
Disclosure of Invention
The invention mainly aims to provide a bus type capacitance sensor for laser cutting, so as to improve the quality of cutting seams during laser cutting.
The invention is realized by the following technical scheme:
in a first aspect, the present invention provides a bus-based capacitive sensor for laser cutting, comprising: the device comprises a signal amplification module, a signal processing module and a communication module;
the signal amplification module comprises an LC oscillation circuit, a signal amplification circuit and a temperature detection module, wherein the LC oscillation circuit is used for acquiring capacitance data of the capacitor to be detected, and transmitting a capacitance data signal to the signal processing module after the capacitance data signal is processed by the signal amplification circuit;
the temperature detection module is used for acquiring and processing temperature data of the capacitor to be detected and transmitting a temperature data signal to the signal processing module;
the signal processing module comprises an FPGA module and a data processing module, capacitance and temperature data information is processed by the FPGA module and then input into the data processing module, an output signal of the data processing module is transmitted to the communication module, the communication module uploads the data to the numerical control system, the numerical control system is calibrated at different temperatures, and the sensor precision at different temperatures is guaranteed.
In a second aspect, the invention further provides a detection system for laser cutting, which comprises an industrial personal computer and the bus-type capacitance sensor in the first aspect, wherein the bus-type capacitance sensor is connected with the capacitor to be detected, and transmits capacitance data of the capacitor to be detected to the industrial personal computer through the communication module.
Compared with the prior art, the invention has the following beneficial effects:
1. the invention collects the capacitance data and the working temperature signal of the sensor at the same time, can calibrate the numerical control system at different temperatures, and ensures the accuracy of the sensor at different temperatures.
2. According to the invention, the frequency modulation signal which is uploaded to the signal processing module by the signal amplification module is subjected to difference frequency and then input into the FPGA, so that the basic frequency of the measured signal is reduced, the signal measurement precision and speed are improved, and the problems that the sensor resolution is low and the precision cannot be achieved when the sensor is applied to three-dimensional laser cutting are solved.
3. The invention uses EtherMac industrial real-time Ethernet to transmit data, thereby ensuring the transmission speed of the data.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application.
Fig. 1 is a schematic structural diagram of a bus type capacitive sensor according to the present invention.
Fig. 2 is a circuit diagram of a difference frequency circuit and a circuit for converting a differential signal into a single-ended signal according to the present invention.
The specific implementation mode is as follows:
the invention is further described with reference to the following figures and examples.
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
In the present invention, terms such as "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "side", "bottom", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only terms of relationships determined for convenience of describing structural relationships of the parts or elements of the present invention, and are not intended to refer to any parts or elements of the present invention, and are not to be construed as limiting the present invention.
In the present invention, terms such as "fixedly connected", "connected", and the like are to be understood in a broad sense, and may be a fixed connection, or may be an integral connection or a detachable connection; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be determined according to specific situations by persons skilled in the relevant scientific or technical field, and are not to be construed as limiting the present invention.
The embodiments of the present invention are described below with reference to the drawings, and the technical solutions in the embodiments of the present invention are clearly and completely described. 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 scope of the present invention.
Example 1
A bussed capacitive sensor for laser cutting comprising: the device comprises a signal amplification module, a signal processing module and a communication module;
the signal amplification module comprises an LC oscillating circuit, a signal amplification circuit and a temperature detection module, wherein the LC oscillating circuit is used for acquiring capacitance data of a measured capacitor, the LC oscillating circuit outputs a frequency modulation sine wave signal of 12 Mhz-14 Mhz, the frequency modulation sine wave signal is directly accessed to the signal amplification circuit in a capacitance coupling mode, and the capacitance data signal is processed by the signal amplification circuit and then transmitted to the signal processing module;
the temperature detection module is used for acquiring and processing temperature data of the capacitor to be detected and transmitting a temperature data signal to the signal processing module;
the signal processing module comprises an FPGA module and a data processing module, capacitance and temperature data information is processed by the FPGA module and then input into the data processing module, and an output signal of the data processing module is transmitted to the communication module.
The FPGA module comprises a frequency detection module and a serial port receiving module, and the capacitance data information is processed by the frequency detection module and then output to the data processing module; the temperature detection module is processed by the serial port receiving module and then transmitted to the data processing module. The communication module uploads the data to the numerical control system, so that the numerical control system can be calibrated at different temperatures, and the sensor precision at different temperatures is ensured.
The capacitance data signal is transmitted to the signal processing module through the signal amplifying circuit in a differential mode; and the temperature data signals are transmitted to the signal processing module by adopting difference.
The signal amplification module further comprises a circuit for converting a single-ended signal into a differential signal, the signal processing module further comprises a circuit for converting a differential signal into a single-ended signal, and the signal amplification module outputs two paths of differential signals which are respectively a capacitance data differential signal and a temperature data differential signal. The signal amplifying circuit outputs square wave signals with variable frequency, the square wave signals are connected into the single-end signal to differential signal converting circuit, and the single-end signals are converted into capacitance data differential signals. The capacitance data differential signal is converted into a capacitance data single-ended signal after being processed by a differential signal to single-ended signal conversion circuit of the signal processing module, and the capacitance data single-ended signal is transmitted to the FPGA module after being processed by a difference frequency circuit.
The temperature data differential signal is converted into a temperature data single-ended signal after being processed by a differential signal to single-ended signal conversion circuit of the signal processing module, and the temperature data single-ended signal is transmitted to a serial port receiving module of the FPGA module.
The difference frequency circuit comprises a serial number C85 capacitor, a serial number C86 capacitor, a serial number C87 capacitor, a serial number U20D trigger, a serial number R118 resistor, a serial number R119 resistor, a serial number R120 resistor, a serial number R122 resistor, a serial number R121 resistor and a serial number R123 resistor, wherein a CLK FX port is connected with the R118 resistor, the R119 resistor and the R120 resistor in series in sequence and then is connected with a fourth pin of the serial number U20D trigger; one end of the C85 capacitor is connected into the CLK FX interface and the R118 resistor connecting section, and the other end of the C85 capacitor is connected with the C86 capacitor and the C87 capacitor and then grounded; one end of the C86 resistor is connected into the resistor connecting section of R118 and R119; one end of the capacitor C87 is connected into the resistor connecting segment of R119 and R120. And one end of the resistor with the number R122 is connected with the 3V voltage, and the other end of the resistor with the number R20 is connected with the fifth pin of the D trigger with the number U20. The third pin of the D flip-flop of U20 is grounded; the second pin of the D flip-flop of U20 is connected to R121 resistor and then switched into the Standard clk interface.
The differential signal to single-ended signal conversion circuit comprises a signal conversion chip with the number R125 resistor, the number R126 resistor and the number U21, one end of the number R125 resistor is grounded, the other end of the number R125 resistor is connected with the R126 resistor, and one end of the R126 resistor is connected with a third pin of the signal conversion chip of the U21; and the R125 resistor and the R126 resistor are connected into the R123 resistor in the resistor connecting circuit, and the R123 resistor is connected with the first pin of the D trigger with the number U20.
The temperature detection module comprises a temperature detection circuit and an MCU, the temperature detection circuit is connected to the MCU, the temperature detection circuit collects temperature information of the detected circuit, the temperature data signal is processed and output through the MCU, and the temperature data signal is transmitted to the signal processing module.
The communication module comprises an EtherMac real-time Ethernet IP core, a first Ethernet interface module and a second Ethernet interface module, and the data processing module sends the processed data to the EtherMac real-time Ethernet IP core; the EtherMac real-time Ethernet IP core is respectively connected with the first Ethernet interface module and the second Ethernet interface module for data exchange, and is connected to the EtherMac communication network in a cascading mode through the first Ethernet interface module and the second Ethernet interface module. The EtherMac real-time Ethernet IP core is in cascade connection with an EtherMac communication network through a first Ethernet interface module and a second Ethernet interface module to serve as an EtherMac node, transmits capacitance data and sensor working temperature to the industrial personal computer or the numerical control system, and then calculates the height through the industrial personal computer or the numerical control system.
The differential signal to single-ended signal conversion circuit receives the capacitance data differential signal and the temperature data differential signal from the signal amplification module and respectively converts the capacitance data differential signal and the temperature data differential signal into two paths of single-ended signals to be connected into the differential frequency circuit and the serial port receiving module.
The difference frequency circuit receives a reference signal from the reference frequency module and a capacitance data signal from the differential signal to single-ended signal circuit, and then outputs a signal to access the frequency detection module; and the frequency detection module and the serial port receiving module send the calculated data to the data processing module.
In other embodiments, there is also provided:
the utility model provides a detecting system for laser cutting, includes, is surveyed the electric capacity, as embodiment 1 the total line formula capacitive sensor and industrial computer, is surveyed the electric capacity with total line formula capacitive sensor is connected, will be surveyed the electric capacity data of electric capacity and transmit to the industrial computer through communication module.
Although the embodiments of the present invention have been described with reference to the accompanying drawings, it is not intended to limit the scope of the present invention, and it should be understood by those skilled in the art that various modifications and variations can be made without inventive efforts by those skilled in the art based on the technical solution of the present invention.
Claims (3)
1. A bus-based capacitive sensor for laser cutting, applied to three-dimensional laser cutting, comprising: the device comprises a signal amplification module, a signal processing module and a communication module;
the signal amplification module comprises an LC oscillation circuit, a signal amplification circuit and a temperature detection module, wherein the LC oscillation circuit is used for acquiring capacitance data of the capacitor to be detected, and transmitting a capacitance data signal to the signal processing module after the capacitance data signal is processed by the signal amplification circuit;
the temperature detection module is used for acquiring and processing temperature data of the capacitor to be detected and transmitting a temperature data signal to the signal processing module;
the signal processing module comprises an FPGA module and a data processing module, capacitance and temperature data information is processed by the FPGA module and then input into the data processing module, and an output signal of the data processing module is transmitted to the communication module;
the signal processing module also comprises a differential signal to single-ended signal conversion circuit;
the differential signal to single-ended signal conversion circuit receives the capacitance data differential signal and the temperature data differential signal from the signal amplification module and respectively converts the capacitance data differential signal and the temperature data differential signal into two paths of single-ended signals to be connected into the differential frequency circuit and the serial port receiving module;
the difference frequency circuit receives a reference signal from the reference frequency module and a capacitance data signal from the differential signal to single-ended signal circuit, and then outputs a signal to access the frequency detection module; the frequency detection module and the serial port receiving module send the calculated data to the data processing module;
the capacitance data signal is processed by the difference frequency circuit and then transmitted to the FPGA module, and the frequency-modulated signal which is uploaded to the signal processing module by the signal amplification module is input into the FPGA after being subjected to difference frequency, so that the basic frequency of the measured signal is reduced, and the signal measurement precision and speed are improved;
the FPGA module comprises a frequency detection module and a serial port receiving module, and the capacitance data information is processed by the frequency detection module and then output to the data processing module; the temperature detection module is processed by the serial port receiving module and then transmitted to the data processing module;
the communication module comprises an EtherMac real-time Ethernet IP core, a first Ethernet interface module and a second Ethernet interface module, and the data processing module sends the processed data to the EtherMac real-time Ethernet IP core; the EtherMac real-time Ethernet IP core is respectively connected with the first Ethernet interface module and the second Ethernet interface module for data exchange, and is connected to the EtherMac communication network in a cascading mode through the first Ethernet interface module and the second Ethernet interface module.
2. The bus type capacitive sensor according to claim 1, wherein the temperature detection module comprises a temperature detection circuit and an MCU, the temperature detection circuit is connected to the MCU, the temperature detection circuit collects temperature information of the circuit to be detected, the MCU processes and outputs a temperature data signal, and the temperature data signal is transmitted to the signal processing module.
3. A detection system for laser cutting is characterized by comprising the bus-type capacitance sensor and an industrial personal computer according to any one of claims 1-2, wherein the bus-type capacitance sensor is connected with a capacitor to be detected, and data of the capacitor to be detected is transmitted to the industrial personal computer through a communication module.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN112525060B (en) * | 2020-12-11 | 2022-11-25 | 固高科技股份有限公司 | Distance measuring device, method and system based on temperature compensation and height regulator equipment |
| CN114682925A (en) * | 2020-12-31 | 2022-07-01 | 大族激光科技产业集团股份有限公司 | Device and method for improving precision and stability of capacitive sensor |
| CN114543648A (en) * | 2022-04-11 | 2022-05-27 | 深圳软动智能控制有限公司 | A metal cutting height sensor |
| CN114785294B (en) * | 2022-06-20 | 2022-09-16 | 南京超颖新能源科技有限公司 | Capacitor acquisition amplifier and laser head adjusting device using same |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102007048812A1 (en) * | 2007-10-10 | 2009-04-16 | Endress + Hauser Conducta Gesellschaft für Mess- und Regeltechnik mbH + Co. KG | Cable circuit with digital signal conditioning |
| CN105115535A (en) * | 2015-09-25 | 2015-12-02 | 成都华太测控技术有限公司 | Simulation apparatus of capacitance sensor |
| WO2018015774A1 (en) * | 2016-07-22 | 2018-01-25 | University Of Zagreb Faculty Of Electrical Engineering And Computing | Device for measurement of temperature or other physical quantities on a rotating assembly where the transmission of signal and energy between rotating and stationary parts is achieved by means of contactless transmission |
| CN110411412A (en) * | 2018-04-27 | 2019-11-05 | 精工爱普生株式会社 | Resampling circuit, physical quantity sensor unit and inertial measurement device |
| CN110823283A (en) * | 2019-09-29 | 2020-02-21 | 大族激光科技产业集团股份有限公司 | Capacitance and temperature signal sensor |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ITUA20163099A1 (en) * | 2016-05-03 | 2017-11-03 | Torino Politecnico | CAPACITIVE SENSOR AND METHOD TO DETECT CHANGES IN A SPACE |
| CN108422079B (en) * | 2016-11-08 | 2020-04-10 | 中国人民解放军空军工程大学航空机务士官学校 | Control device of laser cutting system |
| CN106885948B (en) * | 2017-03-02 | 2019-05-07 | 广东工业大学 | A laser height controller capacitance measuring device |
-
2020
- 2020-03-17 CN CN202010187148.6A patent/CN111352371B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102007048812A1 (en) * | 2007-10-10 | 2009-04-16 | Endress + Hauser Conducta Gesellschaft für Mess- und Regeltechnik mbH + Co. KG | Cable circuit with digital signal conditioning |
| CN105115535A (en) * | 2015-09-25 | 2015-12-02 | 成都华太测控技术有限公司 | Simulation apparatus of capacitance sensor |
| WO2018015774A1 (en) * | 2016-07-22 | 2018-01-25 | University Of Zagreb Faculty Of Electrical Engineering And Computing | Device for measurement of temperature or other physical quantities on a rotating assembly where the transmission of signal and energy between rotating and stationary parts is achieved by means of contactless transmission |
| CN110411412A (en) * | 2018-04-27 | 2019-11-05 | 精工爱普生株式会社 | Resampling circuit, physical quantity sensor unit and inertial measurement device |
| CN110823283A (en) * | 2019-09-29 | 2020-02-21 | 大族激光科技产业集团股份有限公司 | Capacitance and temperature signal sensor |
Non-Patent Citations (2)
| Title |
|---|
| ECT系统微小电容信号采集的研究;周云龙等;《仪表技术与传感器》;20110715(第07期);全文 * |
| 激光传感智能识别系统设计与实现;张秋娜;《激光杂志》;20180625(第06期);全文 * |
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