CN111804467B

CN111804467B - Method, system, host and storage medium for improving coating precision

Info

Publication number: CN111804467B
Application number: CN202010642030.8A
Authority: CN
Inventors: 潘昱凡; 关敬党
Original assignee: Shenzhen Shining Automation Co ltd
Current assignee: Shenzhen Shanying Automation Technology Co ltd
Priority date: 2020-07-06
Filing date: 2020-07-06
Publication date: 2021-07-06
Anticipated expiration: 2040-07-06
Also published as: CN111804467A

Abstract

The application relates to a method, a system, a host and a storage medium for improving coating precision, which comprises a splitting step of splitting a storage space of a memory and establishing a plurality of cache regions, wherein at least one working cache region and one readable cache region exist in the cache regions; a detection step of acquiring pressure data generated by a sensor at a sampling frequency determined by a first transmission protocol; wherein the first transmission protocol is a sensor-PLC information transmission protocol; a writing step, namely synchronously writing the acquired pressure data into a working cache region; a conversion step, converting the working buffer area and the readable buffer area with a reading frequency determined by a second transmission protocol, wherein the sampling frequency is greater than the reading frequency, and the second transmission protocol is an information transmission protocol of the PLC-terminal equipment; and an output step, transmitting all pressure data in the readable buffer area to the terminal equipment according to the reading frequency. The coating liquid flow measuring device has the effect of improving the measuring precision of the output flow of the coating liquid so as to improve the coating precision.

Description

Method, system, host and storage medium for improving coating precision

Technical Field

The present disclosure relates to the field of coating technologies, and in particular, to a method, a system, a host and a storage medium for improving coating accuracy.

Background

In an application apparatus such as a desktop coater for applying a coating liquid to a substrate made of glass or the like, the coating liquid can be applied to the entire substrate with a uniform coating film thickness (a unit in which an allowable error of a film thickness distribution is 1 μm or less). At present, a coater performs spraying in a total of two modes, continuous coating and space coating, respectively, the continuous coating mode being used for producing a coating film of a uniform and large length except for the start and end stages of coating in which a nozzle uniformly and stably discharges a coating liquid. While space coating is often used for pattern spraying, for a discontinuous pattern, the nozzle needs to be turned on and off from time to spray discontinuous coating fluid. The opening and closing of the nozzle is usually controlled by a valve, but when the nozzle is opened and closed, the flow rate in the nozzle is suddenly changed, and if the nozzle cannot be accurately controlled or compensated, the sprayed thickness of the coating liquid is not uniform. And can not directly detect the membrane thickness of wet cloth usually, need detect after drying for the dry piece with wet cloth, but the stoving case has the length of hundreds of meters usually, detects after the stoving that the membrane thickness takes place to fluctuate and when not meeting the requirements, will produce a large amount of defective products, causes a large amount of losses.

At present, a detection device, generally a pressure gauge and a flow meter, is usually disposed at the nozzle for measuring the discharge pressure and the discharge flow rate of the coating liquid at the front end of the nozzle, and people correspondingly adjust the discharge amount of the coating liquid from the nozzle according to the measured data, thereby improving the coating precision and reducing the fraction defective. In the production practice, in order to further improve the coating accuracy, the detection accuracy of the output flow rate is continuously improved, but the applicant finds that, when the detection accuracy of the output flow rate reaches a certain height under the condition that the pressure data is not changed, the coating accuracy is difficult to further improve even if the accuracy is improved to the order of one thousandth. For this reason, one has turned to using other methods to indirectly measure the flow rate of the coating liquid.

In the related art 1, a delivery state measuring portion that measures state quantities (discharge pressure and discharge flow rate) indicating discharge of the coating liquid from the leading end of the nozzle is provided at the nozzle. Which includes a pressure gauge for measuring the discharge pressure of the coating liquid or/and a flow meter for measuring the discharge flow rate of the coating liquid. The manometer samples at a sampling period of 1Kz, and removes a noise component of the measurement data using a 100Hz low-pass filter. Or smoothing the obtained pressure change curve by spline interpolation to remove singular points and discontinuous changes contained in the data.

In the related art 2, it inputs a process parameter to the coater, the process parameter is equal to a ratio of a coating speed to a pressure at which the nozzle discharges the coating liquid, and when the process parameter is stable, it is determined that the film thickness is uniform; and judging that the film thickness is abnormal when the process parameters are unstable.

Similar to the technical solution in the related art 1, the pressure data is preprocessed to be smoother, and from the mathematical statistics perspective, each obtained pressure data includes information of a plurality of original data, that is, it actually becomes a process quantity.

Similar to the solution of the related art 2, it employs a ratio of speed and pressure. The pressure measured by the pressure sensor is an instantaneous quantity, and the speed is a process quantity which is defined as the moving distance of the object in unit time, and the smaller the unit time is, the more accurate the measured speed value is. The average value will be masked by the fluctuation of the instantaneous velocity during a measurement period.

In view of the above, in order to improve the coating accuracy, improvements in the detection method are required.

Disclosure of Invention

In order to improve the accuracy of measuring the output flow of the coating liquid and improve the coating accuracy, the application provides a method, a system, a host and a storage medium for improving the coating accuracy.

In a first aspect, the present application provides a detection method for improving coating accuracy, which adopts the following technical scheme:

a detection method for improving coating accuracy, comprising:

splitting a storage space of a memory and establishing a plurality of cache regions, wherein at least one working cache region and one readable cache region exist in the cache regions;

a detection step of acquiring pressure data generated by a sensor at a sampling frequency determined by a first transmission protocol; wherein the first transmission protocol is a sensor-PLC information transmission protocol;

a writing step, namely synchronously writing the acquired pressure data into a working cache region;

a conversion step, converting the working buffer area and the readable buffer area with a reading frequency determined by a second transmission protocol, wherein the sampling frequency is greater than the reading frequency, and the second transmission protocol is an information transmission protocol of the PLC-terminal equipment;

an output step, transmitting all pressure data in the readable cache region to the terminal equipment according to the reading frequency;

the pressure data quantity which can be stored in the working buffer area and the readable buffer area is larger than or equal to the ratio of the sampling frequency to the reading frequency.

By adopting the technical scheme, the pressure sensor is matched with the PLC for use, and is connected and performs signal transmission through the first transmission protocol when leaving a factory. The pressure sensor can sample the hydraulic pressure of the coating liquid in real time, the collected data is instantaneous quantity, but the PLC can only acquire the pressure data collected by the pressure sensor at a limited frequency due to the limitation of a first transmission protocol. In the process of spraying the coating liquid, the pressure value in the nozzle is constantly changed and is limited by the magnitude of the reading frequency, in the related art, a plurality of pressure data in the buffer area are generally required to be processed and then transmitted to the terminal equipment, partial information of the data is lost in the process, and the lost data information just reflects the fluctuation condition of the flow in one reading period. In order to avoid losing the pressure data, in a reading period, the PLC writes the acquired pressure data into the working cache region, until the period is finished, the working cache region and the readable cache region are switched, and then the pressure data is continuously written into a new working cache region. During the switching process, the buffer area keeps writing of the pressure data from the sensor all the time, and transmits all the pressure data written in the last sampling period to the terminal equipment. The duration of each reading period is enough for the PLC to transmit all the pressure data stored in the PLC to the terminal equipment so as to avoid the loss of pressure data information caused by the limitation of reading frequency. Therefore, people can clearly learn the actual condition of the coating liquid pressure at the nozzle according to complete data information to guide the discharge amount adjustment of the coating machine as a process parameter, so that the film thickness control precision is improved.

Preferably, the splitting step further comprises: establishing an identification bit data block storing a plurality of identification bits, wherein each identification bit corresponds to each cache region;

the conversion step comprises:

reading the identification bits of the working cache region and the readable cache region from the identification bit data block;

modifying the identification bit information at the reading frequency, matching the working cache region with the identification bit of the original readable cache region, and using the working cache region as a new readable cache region; and matching the readable cache region with the identification bit of the original working cache region and using the readable cache region as a new working cache region.

By adopting the technical scheme, the number of the cache regions can be two or more, and when the number of the cache regions is more than two, the cache regions except the working cache region and the readable cache region are idle cache regions. The identification bit is used for marking the cache region, similar to a pointer, and points to the address of the cache region, and the PLC can acquire the corresponding address of the cache region by acquiring the identification bit.

The PLC reads the address corresponding to the work cache region from the identification bit data block, continuously acquires the pressure data acquired by the sensor at the sampling frequency in a reading period, and sequentially writes the pressure data into the work cache region according to the address of the work cache region in a time sequence. When the reading period is finished, the identification bit originally pointing to the working cache region is defined to point to the address of the reading cache region, the identification bit originally pointing to the address of the reading cache region is defined to point to the address of the working cache region, a new reading period is started, and the pressure data are sequentially written into the new working cache region according to the address of the new working cache region. And the old working buffer area, namely the new readable buffer area, transmits all the pressure data stored in the old working buffer area to the terminal equipment according to the second transmission protocol.

Preferably, the sampling frequency is greater than or equal to 500 Hz.

By adopting the technical scheme, the rapid fluctuation of the coating liquid pressure is difficult to detect due to the excessively low sampling frequency, and the oscillation process of the coating liquid pressure is generally 5 ms-15 ms when the valve is opened and closed, so that the sampling frequency at least needs to be higher than 500Hz, and the sampling frequency is preferably 1kHz in the embodiment.

In a second aspect, the present application provides a system based on detection for improving coating accuracy, which adopts the following technical solutions:

a system based on a detection method for improving coating accuracy, comprising:

the memory management system comprises a splitting module, a storage module and a storage module, wherein the splitting module is used for splitting a memory space and establishing a plurality of cache regions, and the cache regions at least comprise a working cache region and a readable cache region;

a detection module for acquiring pressure data generated by the coating liquid discharged from the front end of the nozzle at a sampling frequency determined by a first transmission protocol;

a conversion module for converting the working buffer and the readable buffer into each other at a reading frequency determined by the second transmission protocol;

and the output module is used for transmitting all pressure data in the readable buffer area to the terminal equipment according to the reading frequency.

In a third aspect, the present application provides a host, which adopts the following technical solution:

comprising a memory and a processor, said memory having stored thereon a computer program which can be loaded by the processor and which executes the method according to any of claims 1 to 3.

In a fourth aspect, the present application provides a computer-readable storage medium, which adopts the following technical solutions:

a computer-readable storage medium storing a computer program that can be loaded by a processor and execute any of the above-described methods based on a detection method for improving coating accuracy.

In a fifth aspect, the present application provides a method for improving coating accuracy, which adopts the following technical solutions:

a method for improving coating accuracy, comprising the detection method of any one of the above, and a determination method, the determination method comprising:

presetting, namely generating a standard data set based on input, wherein the standard data set consists of a pressure-time array;

a writing step, continuously reading all pressure data in the readable cache region according to the reading frequency, and correspondingly generating a real-time data group, wherein the real-time data group consists of a pressure-time array;

a comparison step, namely matching pressure-time arrays of the standard data set and the real-time data set at the same time node, and comparing results based on the fluctuation difference value of the pressure data in the standard data set and the real-time data set and a preset fluctuation threshold value; and outputting a corresponding execution signal.

By adopting the technical scheme, people input a standard data set in advance according to the type of a product, and the valve needs to be opened and closed frequently due to the characteristics of patterns and the like of the product, so that the pressure and the flow can be changed correspondingly in the process, and the bottom film moves at a constant speed below the spray head, namely the bottom film moves for a fixed distance for a fixed time, so that the pressure change related to the position of the bottom film can be associated with the time. The pressure-time array in the standard data set is a reference value for the pressure of the coating fluid in the valve at different time nodes. Due to the change of production environment, the change of potential physicochemical properties inside the coating liquid, the structural wear inside the equipment and the like, various factors cause the difference between the actual pressure data and the initial detection input standard pressure data, and the difference is fluctuated and corresponds to the fluctuation difference. The control of the thickness of the film material allows a certain tolerance, and the preset fluctuation threshold value of the pressure data corresponds to the tolerance. When the fluctuation difference value exceeds the preset fluctuation threshold value, or when several fluctuation difference values in continuous time exceed the preset fluctuation threshold value, the system outputs a corresponding execution signal to guide the coating machine or an operator or other equipment to make a targeted response.

Preferably, the alarm or shutdown is performed upon receipt of the execution signal.

By adopting the technical scheme, the pressure data volume acquired by the terminal equipment in each reading period is greatly improved, and although the pressure data volume is limited by the hysteresis of the reading time relative to the sampling time, the reading speed of the terminal equipment is still fast enough for the film material circulation speed. The judging step can judge the spraying pressure in a short time after spraying, can judge that waste chips appear when the spraying pressure exceeds the fluctuation range, and stops the machine according to the execution signal, so that unqualified products generated by continuous coating of the coating machine under the condition that the pressure of the nozzle does not reach the standard can be avoided, and the economic loss is reduced.

Preferably, the method further comprises the following steps:

and a display step, namely generating a visual chart on the terminal equipment according to the time relation of the pressure data transmitted in real time.

By adopting the technical scheme, the visual icon can be used for enabling people to visually know the pressure change of the coating liquid at the nozzle.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the actual condition of the coating liquid pressure at the nozzle can be clearly obtained according to the complete data information to be used as a process parameter to guide the discharge amount adjustment of the coating machine, so that the film thickness control precision is improved;

2. when the pressure data fluctuation is larger than a preset threshold value, a corresponding execution signal can be output to control the shutdown or alarm, so that the coating machine is prevented from continuing to perform coating to reduce loss.

Drawings

FIG. 1 is a block flow diagram of a detection method according to a first embodiment of the present application;

FIG. 2 is a block flow diagram of the transformation step of example one of the present application;

FIG. 3 is a block flow diagram of a determination method according to a first embodiment of the present application;

fig. 4 is a visualization chart in the first embodiment of the present application.

Detailed Description

The present application is described in further detail below with reference to figures 1-4.

At present, a flow rate detection method is usually adopted to obtain the output speed of the coating liquid in the nozzle of the coating machine, and the film thickness is changed by controlling the flow rate. In order to improve the yield of products, the measurement accuracy of the flow rate is naturally improved so that the film thickness can be accurately controlled. However, as the flow rate detection accuracy increases, the film thickness control accuracy is not improved in synchronization, and the film thickness control accuracy is improved only slightly even if the fluctuation of the output flow rate is reduced to the thousandth level. This is mainly because the flow sensor actually collects a process variable. The flow sensor works by measuring the volume of liquid passing through it per unit time and calculating its mean value to obtain the flow rate. When the flow fluctuates instantaneously, the fluctuation value is averaged and cannot be reflected. Therefore, in order to improve the detection accuracy of the output flow rate, the detection time corresponding to each flow rate data acquired as much as possible needs to be acquired, but the shortening of the detection time means that the liquid volume is reduced corresponding to the period of time, which raises a higher requirement on the measurement accuracy of the liquid volume, that is, the measurement error of the liquid volume is reduced in proportion to the detection time, but the current flow rate sensor design cannot achieve the same, which is why the film thickness control accuracy is not correspondingly improved.

In contrast, since the method of improving the flow rate detection accuracy is limited, the coater needs to be debugged at the start of the operation in order to keep the film thickness within the error range. The debugging method comprises the steps of trial coating the bottom film, enabling the wet film to flow into a drying box after coating, drying the wet film into a dry film through the drying box for hundreds of meters, measuring the thickness of the dry film, and adjusting parameters of the coating machine according to the measurement result. After multiple times of debugging, the thickness of the membrane material can be relatively kept within an error range. However, this is a hysteresis test, and if the film thickness fluctuates beyond an error range after the tape is fed out, a waste film material of hundreds of meters is generated when the film thickness detection device gives an alarm.

The first embodiment is as follows:

the embodiment of the application discloses a method for improving coating precision, which is used for instantly guiding the improvement of the coating precision on the premise of not continuously improving the flow detection precision. The method comprises a detection method based on a sensor-PLC-terminal device, and with reference to figure 1, the method comprises the following steps:

the splitting step comprises: splitting a storage space of a memory and establishing a plurality of cache regions, wherein at least one working cache region and one readable cache region exist in the cache regions; and establishing an identification bit data block storing a plurality of identification bits, wherein each identification bit corresponds to each cache region respectively.

The number of the buffers may be two or more, and when there are more than two buffers, the buffers other than the working buffer and the readable buffer are idle buffers. The identification bit is used for marking the cache region, similar to a pointer, and points to the address of the cache region, and the PLC can acquire the corresponding address of the cache region by acquiring the identification bit.

For example, there are two buffers, namely a working buffer and a readable buffer. Two identification bits, which are respectively 0 and 1, are stored in the identification bit data block, wherein 0 corresponds to the working cache region, and 1 corresponds to the readable cache region. Before the working cache region needs to be read, accessing the identification bit data block and searching for 0, and obtaining the address of the working cache region corresponding to 0; and before the scale cache region needs to be read, accessing the identification bit data block and searching for 1, and obtaining the address of the readable cache region corresponding to 1.

The detection step comprises: acquiring pressure data generated by a sensor according to a sampling frequency determined by a first transmission protocol; wherein the first transmission protocol is a sensor-PLC information transmission protocol;

the coating machine comprises a set of feeding system, a discharge port of the feeding system is a three-way valve connected with a nozzle, and when the nozzle is closed, the coating liquid can perform internal circulation in the feeding system; when the nozzle is opened, the coating liquid will flow out of the nozzle. The sensor is a pressure sensor provided in the three-way valve for detecting the hydraulic pressure of the coating liquid in the three-way valve. The sensor is matched with the PLC for use, is connected when being delivered from a factory and carries out signal transmission through a first transmission protocol. Compared with a flow sensor, the pressure sensor can sample the hydraulic pressure of the coating liquid in real time, the acquired data is instantaneous quantity, but the PLC can only acquire the pressure data acquired by the pressure sensor at a limited frequency due to the limitation of a first transmission protocol. The sampling frequency depends on the type of sensor and is typically in the order of hundreds of hertz to kilohertz, i.e. pressure data can be sampled at 0.1ms at the fastest and at 10ms at the slowest.

For example, when the sampling frequency determined by the first transmission protocol is 1kHz, i.e., every 1ms, the pressure sensor transmits a pressure data to the PLC.

The writing step comprises: synchronously writing the acquired pressure data into a working cache region;

since the acquired data needs to be cached to avoid loss, it needs to be written into the cache region. For example, if the sampling frequency is 1kHz, the PLC will acquire 1 pressure data from the pressure sensor every 1ms, and the PLC will write the pressure data into the working buffer at a time in a time sequence.

Referring to fig. 2, the transformation step includes: reading the identification bits of the working cache region and the readable cache region from the identification bit data block; modifying the identification bit information by using the reading frequency determined by the second transmission protocol, matching the working cache region with the identification bit of the original readable cache region, and using the working cache region as a new readable cache region; and matching the readable cache region with the identification bit of the original working cache region and using the readable cache region as a new working cache region. The sampling frequency is greater than the reading frequency, and the second transmission protocol is an information transmission protocol of the PLC-terminal equipment.

Although the sampling frequency of the pressure sensor can reach hundreds of hertz to kilohertz, the reading frequency determined by the second transmission protocol is low compared to the sampling frequency, for example, the terminal HMI can only read pressure data from the PLC with a reading frequency of 10 Hz. In the existing device, the PLC generally stores the pressure data received in a reading cycle in a buffer, calculates the average value of the pressure data in the buffer at the end of the reading cycle, and transmits the calculated average value to the terminal device, and then starts a new reading cycle. In the related art, pressure data is collected at a sampling frequency of 1kHz, and then a low-pass filter of 100Hz is used to remove noise components in the data; or smoothing the pressure change curve by spline interpolation. In the above, the raw pressure data acquired by the PLC is screened and processed in order to reduce the signal transmission amount from the PLC to the transmission device of the terminal and to remove singular points and discontinuous variations included in the data. However, this processing of the raw pressure data, similar to the flow sensor, is actually to change the pressure data transmitted to the terminal device to a process quantity based on the transmission cycle. This will result in some loss of data information.

In practice, however, the pressure value in the nozzle is constantly changing during the spraying of the coating liquid, and the data information lost in the related art reflects the change of the pressure value in one reading period. Similarly, no matter how smooth a piece of paper is, but as the accuracy of observation increases, it can be observed that the surface is still rugged, and the raw pressure data reflects the pressure variations in the adjacent sampling time points.

For example, in the case of intermittent coating, the three-way valve is repeatedly opened and closed. When a valve is opened and closed, the coating liquid pressure in the nozzle is subjected to sudden change, the sudden change is a vibration process, generally, the vibration process is 5 ms-15 ms, and the flow sensor is difficult to detect. When such sudden change occurs without a corresponding compensation measure, the film thickness sprayed at that time is liable to be out of the error range, resulting in the generation of waste pieces. In the above related art, various methods for processing the acquired data in the PLC and transmitting the processed data to the terminal device will result in floating of the measured pressure data.

In the conversion step, the PLC reads the address corresponding to the work cache region from the identification bit data block, continuously acquires the pressure data acquired by the sensor at the sampling frequency in a reading period, and sequentially writes the pressure data into the work cache region according to the address of the work cache region in a time sequence. When the reading period is finished, the identification bit originally pointing to the working cache region is defined to point to the address of the reading cache region, the identification bit originally pointing to the address of the reading cache region is defined to point to the address of the working cache region, a new reading period is started, and the pressure data are sequentially written into the new working cache region according to the address of the new working cache region. And the old working buffer area, namely the new readable buffer area, transmits all the pressure data stored in the old working buffer area to the terminal equipment according to the second transmission protocol. During the switching process, the buffer area keeps writing of the pressure data from the sensor all the time, and transmits all the pressure data written in the last sampling period to the terminal equipment. The duration of each reading period is enough for the PLC to transmit all the pressure data stored in the PLC to the terminal equipment so as to avoid the loss of pressure data information caused by the limitation of reading frequency.

The output step comprises: transmitting all pressure data in the readable cache region to the terminal equipment according to the reading frequency; the pressure data quantity which can be stored in the working buffer area and the readable buffer area is larger than or equal to the ratio of the sampling frequency to the reading frequency.

In order to ensure that the pressure data received by the PLC can be written into the buffer without overflowing during each reading cycle, it is necessary to ensure that the working buffer and the readable buffer have a sufficient space, and the lower limit of the space is the size capable of storing the pressure data corresponding to the ratio of the sampling frequency to the reading frequency. For example, if the sampling frequency is 1kHz and the reading frequency is 10Hz, the space of the working buffer and the readable buffer is required to be able to store at least 100 pressure data.

In summary, the detection method can sequentially and completely transmit all the pressure data that can be acquired by the PLC to the terminal device according to the reading frequency, instead of preprocessing the pressure data in the PLC and then transmitting the pressure data to the terminal device. For example, when the valve is opened and closed, the coating liquid pressure generates abrupt oscillation with the duration of 10ms, if the oscillation is a sine wave with the period of 5ms and the sampling frequency is 1kHz, the pressure sensor can collect five data in each oscillation period, and the five data have large difference, and the pressure change can be obviously found after the five data are transmitted to the terminal equipment. If the PLC performs mean processing or denoising on all pressure data detected in a sudden change period within 10ms, the obtained data cannot reflect the rapid change of the pressure in a short time, and therefore, the guiding significance on the film thickness precision control is lost.

Obviously, the too low sampling frequency will make it difficult to detect the rapid fluctuation of the coating liquid pressure, and since the oscillation process of the coating liquid pressure is generally 20ms to 30ms when the valve is opened and closed, the sampling frequency needs to be at least higher than 500Hz, and is preferably 1kHz in the embodiment.

The method further includes a judgment method based on the detection method, and referring to fig. 3, the judgment method includes the following steps:

and a presetting step, namely generating a standard data set based on the input, wherein the standard data set consists of a pressure-time array.

In the presetting step, one inputs a standard data set in advance according to the type of the product, the valve needs to be opened and closed frequently due to the characteristics of the product such as patterns, the pressure and the flow rate will change correspondingly in the process, and the bottom film moves at a constant speed under the spray head, namely, moves for a fixed distance for a fixed time, so the pressure change related to the position of the bottom film can be related to the time. The pressure-time array in the standard data set is a reference value for the pressure of the coating fluid in the valve at different time nodes. For example, the standard data set in the array of 0-10 ms is as follows:

time (ms)	Coating pressure (Bar)
		1	1.113400
2	1.113100
		3	1.114700
4	1.112700
		5	1.114000
6	1.113300
		7	1.114300
8	1.114200
		9	1.113500
10	1.114900

for example, if the sampling frequency is 1kHz, the reading frequency is 10Hz, and the readable buffer has a capacity to hold 1000 pressure data, then there are only 100 pressure data in the readable buffer, and all of them are output to the terminal device, and the terminal device correlates them with time to generate a real-time data set. For example, the real-time data sets in the 0-10 ms array are as follows:

Time	coating pressure (Bar)
		1	1.113426
2	1.113064
		3	1.114728
4	1.112702
		5	1.114005
6	1.113281
		7	1.114294
8	1.114222
		9	1.113498
10	1.114945

Due to the change of production environment, the change of potential physicochemical properties inside the coating liquid, the structural wear inside the equipment and the like, various factors cause the difference between the actual pressure data and the initial detection input standard pressure data, and the difference is fluctuated and corresponds to the fluctuation difference. The control of the thickness of the film material allows a certain tolerance, and the preset fluctuation threshold value of the pressure data corresponds to the tolerance. When the fluctuation difference value exceeds the preset fluctuation threshold value, or when several fluctuation difference values in continuous time exceed the preset fluctuation threshold value, the system outputs a corresponding execution signal to guide the coating machine or an operator or other equipment to make a targeted response.

For example, as shown in the following table, the preset fluctuation threshold values are-0.001 Bar and 0.001Bar, which are the pressure data pairing information of the standard data set and the real-time data set in 1-10 ms. The difference value between the real-time pressure data and the standard pressure data in the following table is between two preset fluctuation threshold values, and the system outputs an execution signal corresponding to normal work of the machine.

Time (ms)	Coating pressure (Bar)	Coating pressure (Bar)	Difference value
				1	1.113400	1.113426	0.000026
2	1.113100	1.113064	(0.000036)
				3	1.114700	1.114728	0.000028
4	1.112700	1.112702	0.000002
				5	1.114000	1.114005	0.000005
6	1.113300	1.113281	(0.000019)
				7	1.114300	1.114294	(0.000006)
8	1.114200	1.114222	0.000022
				9	1.113500	1.113498	(0.000002)
10	1.114900	1.114945	0.000045

In this embodiment, the system alarms or shuts down when it receives an execution signal.

Through the improvement of the detection method, the pressure data quantity acquired by the terminal device in each reading period is greatly improved, and although the reading time is limited by the hysteresis of the sampling time relative to the reading time, the reading speed of the terminal device is still fast enough for the film material circulation speed. For example, the current film material flowing speed is about 30m/min, which is converted into 0.5mm/ms, so that if the reading frequency is 10Hz, the film material moving distance corresponding to each reading period is 50mm, which is at least four orders of magnitude different from the wet sheet that needs to be dried by hundreds of meters before measurement. The judging step can judge the spraying pressure in a short time after spraying, can judge that waste chips appear when the spraying pressure exceeds the fluctuation range, and stops the machine according to the execution signal, so that unqualified products generated by continuous coating of the coating machine under the condition that the pressure of the nozzle does not reach the standard can be avoided, and the economic loss is reduced.

For example, as shown in fig. 4, a visualization graph generated on the terminal device according to the time relationship of the real-time transmitted pressure data is used. In the related art regarding coating, the first inspection is required each time the coater is turned on. The first sample detection process comprises the steps of coating a section of sample, drying the sample, detecting the thickness, repeating for many times until the detected thickness meets the requirement, and recording related parameters set by the coating machine corresponding to the thickness. The first sample detection method not only causes certain waste, but also needs repeated tests and consumes long time. The method can synchronously generate the visual chart in the coating process during initial detection, and compares the actual waveform with the preset standard waveform to directly adjust the parameters without subsequent drying and thickness measuring operations. And after the parameter adjustment is finished, performing drying and thickness measurement again to confirm whether the requirements are met, and finishing the first sample detection. In contrast, waste and first-check time can be greatly reduced.

For another example, the nozzle in the coating machine supplies materials through a feeding system, the feeding system supplies materials in a metering mode, and discharging precision is accurate. In daily maintenance, the materials need to be sent back to a manufacturer for disassembly, cleaning and maintenance, and the discharging precision of the materials cannot be guaranteed after the materials are reassembled. According to the judging method, when the discharge valve of the coating machine is closed, the coating liquid can be subjected to internal circulation in the feeding system, the sensor continuously obtains the hydraulic pressure of the coating liquid in the three-way valve at the moment, and the terminal equipment can generate a corresponding visual chart. During the internal circulation, if the pressure standard is no longer within the preset range or the pressure-time curve fluctuates all the time, it is indicated that the assembly of the feeding system does not reach the standard, so that the problem can be directly positioned on the feeding system. In the related technical scheme, positions of a dryer, a die head and the like need to be detected and eliminated item by item respectively, so that the problem of the feeding system can be determined, and the feeding system is quite inconvenient.

Example two:

a system based on a method for improving coating accuracy, comprising:

the output module is used for transmitting all pressure data in the readable cache region to the terminal equipment according to the reading frequency;

the preset module generates a standard data set based on the input, wherein the standard data set consists of a pressure-time array;

the writing module is used for continuously reading all pressure data in the readable cache region according to the reading frequency and correspondingly generating a real-time data group, wherein the real-time data group consists of a pressure-time array;

the comparison module is used for matching pressure-time arrays of the standard data set and the real-time data set at the same time node and comparing results based on the fluctuation difference value of the pressure data in the standard data set and the real-time data set and a preset fluctuation threshold value; outputting a corresponding execution signal;

and the display module is used for generating a visual chart on the terminal equipment according to the time relation of the real-time transmitted pressure data.

Example three:

a host computer comprising a memory and a processor, the memory having stored thereon a computer program capable of being loaded by the processor and executing the detection method for improving coating accuracy of the embodiments. The host can be a terminal device with various storage and processing capabilities such as a PC, a mobile phone, a tablet and the like.

Example four:

a computer-readable storage medium storing a computer program that can be loaded by a processor and executes any of the above-described methods based on a detection method for improving coating accuracy. The computer-readable storage medium includes, for example: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. A detection method for improving coating accuracy, comprising:

a detection step of acquiring pressure data generated by a sensor at a sampling frequency determined by a first transmission protocol; the first transmission protocol is an information transmission protocol of a sensor-PLC, and the sampling frequency is more than or equal to 500 Hz;

the number of the pressure data which can be stored in the working buffer area and the readable buffer area is respectively more than or equal to the ratio of the sampling frequency to the reading frequency.

2. The inspection method for improving coating accuracy according to claim 1,

the splitting step further comprises: establishing an identification bit data block storing a plurality of identification bits, wherein each identification bit corresponds to each cache region;

the conversion step comprises:

3. A system based on a detection method for improving coating accuracy, comprising:

4. A host comprising a memory and a processor, the memory having stored thereon a computer program that can be loaded by the processor and that executes the method according to claim 1 or 2.

5. A computer-readable storage medium, in which a computer program is stored which can be loaded by a processor and which executes the method according to claim 1 or 2.

6. A method for improving coating accuracy, characterized by comprising a judging method and the detecting method of claim 1 or 2, the judging method comprising:

7. Method for improving coating accuracy according to claim 6, characterized in that an alarm or a shutdown is performed upon reception of the execution signal.

8. The method for improving coating accuracy of claim 6, further comprising: