CN114659595B - Intelligent test device and method for water meter durability based on Internet of Things - Google Patents

Abstract

The invention discloses an intelligent water meter durability test device and method based on the Internet of things, and relates to the field of flow metering verification. The device improves the space utilization rate through a three-dimensional structural design; secondly, based on the machine vision function of the image recognition technology, a CCD camera is adopted to realize the automatic acquisition of the data of the water meter to be detected; meanwhile, wireless transmission of standard flow signals is realized by using a wireless intelligent water meter; and finally, remote monitoring of the test process is realized by using a mobile terminal control program. Thereby realize the promotion of water gauge durability device in the aspect of integrating, automation, intellectuality.

Description

Intelligent test device and method for water meter durability based on Internet of Things

technical field

The invention belongs to the field of flow measurement verification, and in particular relates to a water meter durability intelligent test device and method based on the Internet of Things.

Background technique

The accuracy of the measurement of cold water meters for civil drinking water is directly related to the interests of residents. The national metrological verification regulations only require mandatory verification for the first time, use within a time limit, and rotate upon expiration. Metering performance is very important. The water meter durability test device tests the durability of the water meter under periodic flow conditions and the durability under continuous and overload flow conditions by simulating the actual use conditions and performing intermittent flow life test and continuous flow life test on the water meter. .

In the past ten years, with the continuous development of hardware and software technology, the water meter durability device has been upgraded from the first generation to the second generation. The core technology is based on the stepper motor to control the intermittent flow control valve, which is controlled by the stepper motor. , the valve switching speed can be precisely controlled at _0.15Q3 . Compared with the first-generation water meter durability test device, the second-generation water meter durability test device has the following improvements: (1) The workbench is lengthened and widened, so that 12 water meters can be tested in 4 batches at the same time. The device can only carry out 3 sets of 1 batch test; (2) realize the digital transmission of monitoring data, and upgrade the float flowmeter, pressure gauge and plug-in mercury thermometer in the first-generation device to monitor flow, pressure and temperature respectively to electromagnetic Flow meters, temperature sensors, and pressure transmitters for improved signal transmission strength and accuracy. (3) Optimize the control system to realize automatic reading, recording and printing of some data in the test process.

Nonetheless, the existing second-generation devices still suffer from the following drawbacks:

1. The degree of device integration is low. In order to increase the number of test prototypes, the length and width of the workbench are lengthened, resulting in an increase in the footprint of the device and a decrease in the convenience of operation.

2. The automation level of the device is low. The flow data of the test water meter is still manually read, which has low work efficiency and data accuracy is easily affected by human factors.

3. The intelligent ability of the device is weak. According to GB/T 778-2018 "Drinking Cold Water Meter and Hot Water Meter" and JJF1777-2019 "Drinking Cold Water Meter Type Evaluation Outline", more detailed requirements are put forward for each test item of the water meter. The total flow and continuous flow test takes about 1,000 hours, and it takes 42 days to complete the test if it runs 24 hours a day. If the device has no monitoring function and remote control function, it needs to be checked regularly by the test personnel, and there are certain security risks.

Therefore, the integration, automation and intelligence of the lifting device is an inevitable trend in the research and development of the third-generation water meter durability device.

SUMMARY OF THE INVENTION

In view of the above technical deficiencies, the present invention provides a water meter durability intelligent test device and method based on the Internet of Things, so as to improve the integration, automation and intelligence of the existing water meter durability device.

The invention firstly improves the space utilization rate through the three-dimensional structure design; secondly, the machine vision function based on the image recognition technology realizes the automatic collection of the measured water meter data; at the same time, the wireless intelligent water meter is used to realize the wireless transmission of the standard flow signal; The terminal control program realizes the remote monitoring of the test process.

In order to realize the purpose of the present invention, the following scheme is specifically adopted:

The intelligent test device for water meter durability based on the Internet of Things in the present invention includes a control system, a water supply system and a pipeline system.

The water supply system includes a water tank, a first automatic ball valve, a vertical water pump, a water inlet valve, and a drain valve.

The pipeline system includes a pressure sensor, a temperature sensor, a second automatic ball valve, a meter clamp, a third automatic ball valve, a wireless flow meter, and a flow regulating valve.

The control system includes a PLC controller, a host computer, a repeater, and a CCD camera.

The water tank is connected with the water inlet of the vertical water pump through the first automatic ball valve; there are three vertical water pumps, and the water outlet of each vertical water pump is connected with a second automatic ball valve, and is close to each vertical water pump. A pressure sensor and a temperature sensor are arranged on the pipeline of the second automatic ball valve; the water outlet at the other end of each second automatic ball valve is connected with the water inlet of the meter clamp; the water meters to be tested are placed in series, and the outermost ends are clamped by the meter clamp The water outlet of the clamp meter is connected to the water inlet of a third automatic ball valve; the water outlet of each third automatic ball valve is connected to a wireless flowmeter; the water outlet of each wireless flowmeter is connected to the water tank through a flow regulating valve; The water tank is provided with an inlet valve and a drain valve for water inlet and drainage.

The PLC controller is connected with the first automatic ball valve, the vertical water pump, the pressure sensor, the temperature sensor, the second automatic ball valve, the third automatic ball valve, the flow regulating valve and the upper computer.

The signal of the wireless flow meter is transmitted to the repeater, and the signal of the repeater is uploaded to the upper computer.

The CCD camera is arranged above the dial of the water meter to be tested, reads the dial digitally, and is connected with the host computer;

The image processing software is executed in the upper computer to identify the indicated volume displayed by the measured water meter and store the data; the image processing software includes an automatic positioning unit and an automatic identification unit.

The automatic positioning unit includes an edge detection unit, an angle detection unit and a character segmentation unit, wherein the edge detection unit is used to highlight the character wheel frame of the dial, so as to facilitate the detection of the upper and lower boundaries; the angle detection unit is used to extract from the edge image. The character wheel frame is detected; the character segmentation unit is used to record the number of pixels corresponding to each row or column in the character wheel frame, and determine the boundary according to the number.

The automatic recognition unit includes a character extraction unit and a character recognition unit, and the character extraction unit is used to perform a threshold operation on a grayscale image to obtain a binary image, and perform outermost contour detection; traverse all detected contours to obtain each A circumscribed rectangle of an outline; the character recognition unit uses a template matching method to perform character recognition.

Further, the CCD camera is fixedly arranged at the surface position of each water meter to be tested.

Furthermore, a single CCD camera is installed in the pipeline system, and a stepping motor is used to control the CCD camera to advance along the pipeline, so as to realize the recording of the dial plate.

Furthermore, as needed, 1 to 3 piping systems are set up and the durability test is carried out at the same time.

Further, the wireless flow meter adopts LoRa wireless ultrasonic smart water meter.

Further, multiple LoRa wireless ultrasonic smart water meters are connected to GSM wireless data collectors, and use the GSM network to upload data to the repeater to form a wireless monitoring system.

The method for the intelligent test of water meter durability based on the Internet of Things in the present invention comprises the following steps:

Step1: According to the test requirements, complete the installation of multiple batches of tested water meters on the water meter durability intelligent test device;

Step2: According to the water meter durability test requirements, set the relevant parameters on the host computer; set the measured water meter reading value to be taken every 24 hours;

Step3: The upper computer controls the vertical water pump to open and supply water;

Step4: The upper computer reads the upstream water pressure of the tested water meter, the upstream water temperature of the tested water meter, the flow through the tested water meter, the duration of the four stages of each cycle in the intermittent flow test, the number of cycles, and the indication of the tested water meter Volume; if it is interrupted once, it needs to be read again and written to the database;

Step5: Save the collected data or abnormal alarm information and send it to the user's mobile phone;

Step6: Stop the test after completing all the test requirements.

The beneficial effects of the present invention are:

(1) Three-dimensional structure design to improve laboratory space utilization;

(2) Wireless data transmission reads standard flow signals;

(3) The image recognition technology regularly shoots and recognizes the reading of the tested water meter to realize artificial intelligence;

(4) The mobile terminal control program realizes platform-based remote monitoring, data reading and viewing, differential display and modification of abnormal data, SMS reminder of key test status, and unmanned operation during the test process.

Description of drawings

Fig. 1 is a schematic diagram of a water meter durability intelligent test device based on the Internet of Things of the present invention;

FIG. 2 is a flow chart of the water pen recognition method of the present invention.

In the figure: 1. Water tank; 2. The first automatic ball valve; 3. Vertical water pump; 4. Pressure sensor; 5. Temperature sensor; 6. The second automatic ball valve; 7. Water meter to be tested; 8. CCD camera; 9. Clamping device; 10. The third automatic ball valve; 11. Wireless flowmeter; 12. Flow regulating valve; 13. Water inlet valve; 14. Drain valve.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

The three-dimensional structure design is an inevitable trend in the development of modern equipment. It has the advantages of small footprint and high space utilization, which can effectively alleviate the current situation of tight laboratory resources. Considering the convenience of installing and disassembling the tested sample and the moving track layout of the industrial camera used for automatic reading of the water meter under test, the three-dimensional spatial layout should be combined with an appropriate gradient.

As shown in FIG. 1 , the IoT-based water meter durability intelligent test device in this embodiment adopts a parallel connection of multiple water meter lines, including a control system, a water supply system, and a pipeline system. The water supply system includes a water tank 1 , a first automatic ball valve 2 , a vertical water pump 3 , a water inlet valve 13 and a drain valve 14 .

In this embodiment, the pipeline system includes a pressure sensor 4 , a temperature sensor 5 , a second automatic ball valve 6 , a meter clamp 9 , a third automatic ball valve 10 , a wireless flow meter 11 , and a flow regulating valve 12 .

In this embodiment, the control system includes a PLC controller, a host computer, a repeater, and a CCD camera 8 . The PLC controller is connected to the first automatic ball valve 2, the vertical water pump 3, the pressure sensor 4, the temperature sensor 5, the second automatic ball valve 6, the third automatic ball valve 10, the flow regulating valve 12 and the host computer, and the CCD camera is connected to host computer.

In this embodiment, the water tank 1 is connected to the water inlet of the vertical water pump 3 through the first automatic ball valve 2; the water outlet of the vertical water pump 3 is connected to the second automatic ball valve 6, and the pipeline close to the second automatic ball valve 6 A pressure sensor 4 and a temperature sensor 5 are arranged on it; the water outlet at the other end of the second automatic ball valve 6 is connected with the water inlet of the meter clamp 9; the three measured water meters 7 of each batch are placed in series, and the outermost ends are The meter clamp 9 is clamped; the water outlet of the meter clamp 9 is connected with the water inlet of the third automatic ball valve 10; the water outlet of the third automatic ball valve 10 is connected with the wireless flowmeter 11; the water outlet of the wireless flowmeter 11 passes through the flow regulating valve 12 Connect to tank 1. The water tank is provided with a water inlet valve 13 and a drain valve 14 for water inlet and drainage.

In this embodiment, the CCD camera 8 is arranged above the dial of the water meter 7 to be tested, and digitally reads the dial. The CCD camera 8 uploads the read value to the host computer through wireless transmission. The measurement system in the host computer uses image processing software to identify the indicated volume displayed by the measured water meter 7 and store the data, as shown in Figure 2.

The image processing software in this embodiment includes an automatic positioning unit, an automatic identification unit, and a font library unit; the general concept of software design: the system first preprocesses the image according to the input image, and filters out abnormal images. Then, the position of the characters in the picture is automatically positioned, and then a single character is obtained by segmenting according to the positioning parameters, and finally the character is recognized. The characters to be recognized have a standard template, which is stored in the font unit, and will be matched according to the standard template during the character recognition process.

Before image processing, image preprocessing is generally required, including judging the width, height and quality of the image separately, and screening out the abnormal situations that the width is too small, the height is too small, and the monochrome without dial. In the initialization of the positioning parameters, the offset angle is set to zero, and the upper and lower boundaries and the left and right boundaries are set to default values.

The automatic positioning unit includes an edge detection unit, an angle detection unit and a character segmentation unit, wherein the edge detection unit is used to highlight the character wheel frame of the dial, so as to facilitate the detection of the upper and lower boundaries; the present embodiment adopts the Canny edge detection operator, First, remove the noise. In general, denoising is convolved with a Gaussian smoothing filter. The gradient magnitude and direction are then calculated. Next, non-maximum suppression is performed. This step excludes non-edge pixels and only keeps some thin lines (candidate edges). As a final step, Canny uses the hysteresis threshold, which requires two thresholds (high and low). If the magnitude of a pixel location exceeds a high threshold, the pixel is reserved as an edge pixel. If the magnitude of a pixel location is less than the threshold, the pixel is excluded. If the magnitude of a pixel location is between two thresholds, the pixel is only retained if it is connected to a pixel above the high threshold.

The angle detection unit is used to detect the character wheel frame from the edge image; for the instrument, the upper and lower boundaries of the character wheel frame are the two longest straight lines in the edge image, and this embodiment is also implemented based on Hough transformation. Character wheel frame detection. Hough transform is a method of identifying geometric shapes from images. It uses the duality of point and line to transform a given line in the original image space into a point in the Hough parameter space. Therefore, the problem of detecting a given line in the original image is transformed into a peak problem in the Hough parameter space, that is, the detection of the overall characteristics is transformed into the detection of local characteristics. In this embodiment, the default positions and heights of the upper and lower boundaries of the character wheel are used as initial values, a pair of peak points are searched in the Hough parameter space, and the search range is continuously narrowed through an iterative optimization strategy to shield the interference of nameplates, water ripples, and strong light. , and then determine the best candidate for the upper and lower edge lines of the character wheel frame. After the upper and lower edge lines are determined, the offset angle and the upper and lower boundaries can be further calculated.

The character segmentation unit is used to record the number of pixels corresponding to each row or column in the character wheel frame, and determine the boundary according to the number; specifically, the projection method can be used. The main idea of the projection method is to record the desired pixels corresponding to each row or column. The number of , and then judge whether it is a boundary or a desired object according to these numbers. The number of pixels is like a threshold, and finally the number of points in each line can be drawn for intuitive observation.

The automatic recognition unit includes a character extraction unit and a character recognition unit, which are mainly based on the input instrument image and the set positioning parameters to automatically recognize the reading of the character wheel. The automatic identification function is closely related to the phenotypic structure parameters, positioning parameters and font library. It requires that the position of the character wheel region in the image remains unchanged, and the lighting conditions are not limited.

The image also needs to be preprocessed before the execution of this unit, specifically: the width, height, font library, character height, character width, character spacing and positioning parameter boundary of the image are judged separately. Screen out abnormal situations such as image width is too small, image height is too small, font file error, character height and width exceeding the limit, uneven character spacing and positioning parameters out of bounds.

The character extraction unit is used to perform a threshold operation on the grayscale image to obtain a binary image, and perform outermost contour detection; traverse all detected contours to obtain the circumscribed rectangle of each contour.

The character recognition unit uses a template matching method to perform character recognition. The main idea is to use template matching for identification. Template matching is the most basic way of pattern recognition to find images that match a template image. The template matching method used in water meter character recognition usually needs to first classify the water meter character pictures, that is, by creating the font library corresponding to different water meter pictures, obtain the digital model of 0-9, and then calculate the relationship between each template character and Similarity between characters to match. The one with the highest similarity will be regarded as the recognition result.

The character library unit is used in character recognition, and is a standard character template in the template matching process. Font files are marked in ".dat" format. The character library file stores the overall structure characteristic parameters of the character wheel and the characteristic parameters of each character bit. Each character wheel type corresponds to a character library. If the character wheels of the two watches are the same, the same character library can be shared for image recognition. Both automatic positioning and automatic identification algorithms need to be based on the parameter information in the font file. The font file parameters related to automatic positioning include the ratio of the width of a single character to the character spacing, the number of pixels corresponding to normal characters, and the default vertical coordinates of the upper and lower boundaries of the normal character wheel frame.

In this embodiment, the CCD camera 8 is fixedly set at each measured water meter surface, or a CCD camera 8 is set in a single pipeline system, and a stepping motor is used to control the CCD camera 8 to advance along the pipeline and realize data shooting.

In the present invention, there are three identical pipeline systems, and the high and low are arranged in parallel. According to needs, 1 to 3 pipelines can be tested at the same time. When each pipeline system is working, the CCD camera 8 is turned on to work together.

In this embodiment, the wireless flow meter 11 uses LoRa wireless ultrasonic intelligent cold water water meter to replace the existing electromagnetic flow meter as the monitoring of the test standard flow, and can realize the wireless transmission of data. The LoRa wireless ultrasonic smart water meter integrates measurement, calculation, display, and LoRa wireless communication. It adopts micro-power consumption technology. At the same time, the meter has the characteristics of small size, good stability, and strong anti-interference ability. The ultrasonic flow measurement technology is adopted, which can realize multi-angle installation, the instrument measurement is not affected, and the pressure loss of the pipeline is minimized. Multiple LoRa wireless ultrasonic smart water meters are connected to GSM wireless data collectors, and use GSM network to upload data to wireless LoRa repeaters to form a wireless monitoring system. The upper computer is provided with an ultrasonic intelligent water meter wireless communication module to collect data uploaded by the line LoRa repeater.

Carry out a durability test test on the water meter under test. The test requires reading the test water meter reading at least once every 24 hours. The test period of continuous durability takes 4-5 days, and the test period of intermittent durability takes 38-40 days. , the whole test period is 43-45 days.

Using the IoT-based water meter durability intelligent test device of the present invention, the method for carrying out the durability test test on the water meter under test specifically includes:

Step1: According to the test requirements, complete the installation of multiple batches of tested water meters on the water meter durability intelligent test device;

Step2: According to the water meter durability test requirements, set the relevant parameters on the host computer; set the measured water meter reading value to be taken every 24 hours;

Step3: The upper computer controls the vertical water pump to open and supply water;

Step4: The upper computer reads the upstream water pressure of the tested water meter, the upstream water temperature of the tested water meter, the flow through the tested water meter, the duration of the four stages of each cycle in the intermittent flow test, the number of cycles, and the indication of the tested water meter volume; if interrupted

It needs to be read once again and written to the database;

Step5: Save the collected data or abnormal alarm information and send it to the user's mobile phone;

Step6: Stop the test after completing all the test requirements.

The present invention utilizes the machine vision technology of image recognition word wheel, which can effectively liberate the simple manpower work of the test personnel and improve the automation degree of the equipment. In the background, the mobile terminal data verification and confirmation are combined. If the identification data is found to be abnormal, the corresponding image can be directly called up on the mobile terminal for manual secondary determination. Through the three-dimensional structure design, it can meet the durability test of 36 pieces and 12 batches of DN15~DN25 cold water water meters at the same time.

The above are only preferred embodiments of the present invention, and are not intended to be the only or limit the present invention. Those skilled in the art should understand that, without departing from the scope of the present invention, various changes or equivalent substitutions made to the present invention all belong to the protection scope of the present invention.

Claims (7)

1. The water meter durability intelligent test device based on the Internet of things is characterized by comprising a control system, a water supply system and a pipeline system;

the water supply system comprises a water tank, a first automatic ball valve, a vertical water pump, a water inlet valve and a water discharge valve;

the pipeline system comprises a pressure sensor, a temperature sensor, a second automatic ball valve, a meter clamping device, a third automatic ball valve, a wireless flowmeter and a flow regulating valve;

the control system comprises a PLC (programmable logic controller), an upper computer, a repeater and a CCD (charge coupled device) camera;

the water tank is connected with a water inlet of the vertical water pump through a first automatic ball valve; the water outlet of each vertical water pump is connected with one second automatic ball valve, and a pressure sensor and a temperature sensor are arranged on a pipeline close to each second automatic ball valve; the water outlet at the other end of each second automatic ball valve is connected with the water inlet of the meter clamping device; the water meters to be measured are placed in series, and the two outermost ends are clamped by the meter clamping devices; the water outlet of the meter clamping device is connected with the water inlet of a third automatic ball valve; the water outlet of each third automatic ball valve is connected with a wireless flowmeter; the water outlet of each wireless flowmeter is connected with the water tank through a flow regulating valve; the water tank is provided with a water inlet valve and a water discharge valve for water inlet and water discharge;

the PLC is connected with a first automatic ball valve, a vertical water pump, a pressure sensor, a temperature sensor, a second automatic ball valve, a third automatic ball valve, a flow regulating valve and an upper computer;

the signal of the wireless flowmeter is transmitted to a repeater, and the signal of the repeater is uploaded to an upper computer;

the CCD camera is arranged above the dial plate of the water meter to be measured, and is used for digitally reading the dial plate and is connected with an upper computer;

the upper computer executes image processing software to identify the indicated volume quantity displayed by the water meter to be detected and stores the volume quantity as data; the image processing software comprises an automatic positioning unit and an automatic identification unit;

the automatic positioning unit comprises an edge detection unit, an angle detection unit and a character segmentation unit, wherein the edge detection unit is used for highlighting a character wheel frame of the dial plate so as to facilitate the detection of the upper boundary and the lower boundary; the angle detection unit is used for detecting the character wheel frame from the edge image; the character segmentation unit is used for recording the number of pixels corresponding to each row or each column in the character wheel frame and judging a boundary according to the number;

the automatic identification unit comprises a character extraction unit and a character identification unit, wherein the character extraction unit is used for carrying out threshold operation on the gray level image to obtain a binary image and carrying out outermost layer contour detection; traversing all the detected outlines to obtain a circumscribed rectangle of each outline; the character recognition unit recognizes characters by using a template matching method.

2. The Internet of things-based intelligent water meter durability test device according to claim 1, wherein the CCD camera is fixedly arranged at each measured water meter position.

3. The intelligent durability test device for the water meter based on the internet of things as claimed in claim 1, wherein a single pipeline system is provided with a CCD camera, and a stepping motor is adopted to control the CCD camera to advance along the pipeline, so as to realize dial shooting.

4. The Internet of things-based intelligent durability test device for the water meters as claimed in claim 1, wherein 1-3 pipeline systems are arranged as required to perform durability tests simultaneously.

5. The Internet of things-based intelligent water meter durability test device according to claim 1, wherein the wireless flow meter is a LoRa wireless ultrasonic intelligent water meter.

6. The Internet of things-based intelligent water meter durability test device according to claim 5, wherein a plurality of LoRa wireless ultrasonic intelligent water meters are connected with a GSM wireless data acquisition unit in a matching mode, and data are uploaded to a repeater through a GSM network to form a wireless monitoring system.

7. The intelligent durability test method for the water meter based on the Internet of things is characterized by comprising the following steps of:

step 1: according to the test requirements, the installation of the water meters to be tested in multiple batches on the intelligent water meter durability test device is completed;

step 2: setting relevant parameters on an upper computer according to the water meter durability test requirement; setting a reading value of the water meter to be measured, which is shot every 24 hours;

step 3: the upper computer controls the vertical water pump to start and supply water;

step 4: the upper computer reads the upstream water pressure of the measured water meter, the upstream water temperature of the measured water meter, the flow passing through the measured water meter, the duration time of each cycle of four stages in the interrupted flow test, the cycle times and the indicated volume of the measured water meter; if the interruption is once, the data needs to be read again and written into the database;

step 5: storing and sending the acquired data or abnormal alarm information to a user mobile phone end;

step 6: and stopping the test after all test requirements are completed.

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