Design method of portable iron ion analyzer based on machine vision

Abstract

The invention discloses a design method of a portable iron ion analyzer based on machine vision, which is used for rapidly and accurately measuring the concentration of soluble iron in underground water on site. According to the equipment, a paper-based analysis device (PAD) is combined with an advanced machine vision and image processing technology, median filtering and Hough transform edge segmentation are included, color signals generated by chemical reaction on the surface of the PAD are accurately captured and processed, color signals of an ROI are extracted to serve as input parameters, a multiple regression model is established for quantitative analysis of the iron concentration, and the detection accuracy of the iron concentration is improved. And data backup is carried out in time. The system is mainly composed of four functional modules: an image information acquisition module, a tool and waste module, a power supply and control module and a key interaction and display module. The equipment is simple to operate, can complete measurement by one key, and has certain universality in the direction of detecting metal ions in water by an analytical chemical colorimetric method.

Description

Technical Field

[0001] The present invention relates to embedded device development, software program design, power supply design, 3D modeling and printing technology, GPS communication technology and cloud backup technology, etc. Background Art

[0002] Iron is an indispensable element in the ecological environment and human health. It plays an important role in key physiological processes such as oxygen transport, DNA synthesis and cellular respiration. However, excessive concentrations of soluble iron ions in groundwater pose a threat to the environment and health, and may lead to drinking water pollution, contamination of fixtures, and increase health risks such as hemochromatosis. In addition, elevated iron concentrations can promote the growth of iron-oxidizing bacteria, affect water quality, and disrupt the balance of aquatic ecosystems. Therefore, obtaining accurate concentration data of iron ions in groundwater is crucial to understanding its biogeochemical cycle.

[0003] The form and concentration of iron ions in groundwater are affected by a variety of environmental factors, including pH, redox conditions, and the presence of other minerals. These factors may cause iron to transform between different forms, thereby changing the form and concentration of iron due to oxidation or precipitation in traditional laboratory analysis. Therefore, in situ measurement techniques are considered to be ideal methods to obtain accurate data on iron concentration in groundwater. Although traditional methods such as atomic absorption spectroscopy (AAS) and inductively coupled plasma mass spectrometry (ICP-MS) have high sensitivity and accuracy, their operational complexity and reliance on laboratory infrastructure limit their feasibility of field deployment.

[0004] Currently, methods using paper analysis devices (PADs) combined with digital image processing provide fast, cost-effective analytical processes that have the potential for reliable measurements on site, but lack an iron ion detection device that is easy to carry, simple to operate, and provides timely feedback of results. The present invention combines PADs with machine vision technology to provide a generalizable framework that can be adapted to other analytes through appropriate modifications. Further image processing algorithms and regression models can expand its applicability to a wider range of analytes and more complex water matrices.

[0005] To realize the design of portable iron ion analyzer, the main work includes the following three aspects:

[0006] (1) Based on actual functional requirements, select appropriate industrial cameras, development boards, mobile power supplies, etc., and design a reasonable overall appearance and architecture of the equipment.

[0007] (2) Embedded device hardware development and debugging: write iron ion analysis program and device interface display program, and integrate them into the development board for hardware and software joint debugging.

[0008] (3) Design a suitable power module according to the power and voltage of the electronic equipment, use the shapr3D tool to design the analyzer housing, print the housing using 3D printing technology, and assemble and debug it. Summary of the invention

[0009] In order to overcome the shortcomings of the above-mentioned prior art, the present invention proposes a design method of a portable iron ion analyzer based on machine vision, which is mainly composed of four functional modules: image information acquisition module, tool and waste module, power supply and control module, key interaction and display module. Prepare the water sample to be tested, add the water sample to the PAD and push it into the device through the small drawer, press the start button to complete the entire measurement work, and back up the obtained data information to the cloud server in time.

[0010] The technical solution adopted by the present invention is:

[0011] Step 1: Design the overall structure and divide the portable iron ion analyzer into four modules: image information acquisition module, tool and waste module, power supply and control module, and button interaction and display module.

[0012] Step 2: Debug the industrial camera and control the development board to acquire high-quality images;

[0013] Step 3: Use Python's PyQt5 graphical interface library to develop a graphical interface program, including the open_show startup interface display, the processing_show processing progress interface display, and the final result_show result interface display. The interfaces are all displayed on an LCD screen connected to the development board through the MIPI interface;

[0014] Step 4: Image processing for iron quantification, including median filtering to reduce noise and using Hough transform to identify ROI area for preprocessing, extracting the color signal of ROI area as input parameter, and establishing a multivariate regression model for quantitative analysis of iron concentration;

[0015] Step 5: Set up the Alibaba Cloud server. After executing the analysis process, obtain the measurement point information through the GPS module, execute the data backup program, obtain the cloud server user name, password, SSH key and other necessary information, and upload the analysis results and related data to the Alibaba Cloud server in real time for backup;

[0016] Step 5: Use shapr3D software to design the device shell model, print the shell through 3D printing technology, deploy the hardware module to the corresponding position of the shell, and debug to achieve the effect.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) Developed a portable iron ion analyzer that combines paper chip with machine vision;

[0019] (2) Simple operation, enabling seamless interaction with anyone, anywhere;

[0020] (3) It has significant advantages such as low cost, simple operation, high detection efficiency, and strong anti-interference ability. It is suitable for Fe 3+ Rapid concentration detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The following is the overall appearance of the equipment.

[0022] Figure 2 The following is a diagram of the internal structure of the device.

[0023] Figure 3 For: Device hardware communication diagram.

[0024] Figure 4 For: Equipment program flow chart.

[0025] Figure 5 This is the flow chart of the equipment for iron ion analysis. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings.

[0027] First, according to the functions to be realized by the equipment, the overall framework is designed, the required functional modules are determined and partitioned, and the overall appearance and internal structure are designed, such as Figure 1 , 2 As shown. The overall design is simple and easy to carry. The device consists of four modules, namely image information acquisition module, tool and waste module, power supply and control module, key interaction and display module, covering all tools and devices required for measurement work, providing a guarantee for the simple and portable realization of outdoor measurement work.

[0028] In the whole device, the communication between modules follows the traditional physical communication mode, such as Figure 3As shown. The RK3399 microcontroller is connected to the GPS module through the UART interface. After power-on, it will periodically transmit NMEA protocol statements containing location data to obtain accurate location information of the measurement point. At the same time, the development board is connected to the 4G module through the UART interface, and the SIM card provides traffic to upload the measurement results and location and time data to the cloud server for timely backup. The development board controls the industrial camera through the Ethernet interface and is connected to the lithium battery through the DC port. The power management chip is responsible for voltage regulation to ensure the safety and reliability of the equipment. The user operation button is connected to the development board through the general input and output (GPIO) port to control the entire measurement process. The development board is connected to the LCD display through the MIPI interface, which is convenient for users to operate and view measurement results.

[0029] The software system of the present invention is mainly used for interactive control of the hardware part, image processing and iron quantification, so as to help users realize the entire measurement process. It is developed using python3.9, and mainly includes core programs such as image acquisition, image processing and analysis, data transmission, and operation display. The LCD screen interface display program includes three graphical interface programs, including the power-on interface, the "processing" interface, and the measurement result interface, which are developed using the PyQt5 library. For the iron concentration analysis part, we adopted a series of advanced algorithms, including filtering algorithms, color space conversion algorithms, and concentration analysis algorithms. For PAD images, we usually use the median filtering algorithm for noise reduction, which effectively eliminates the noise interference in the image. Subsequently, we use the edge segmentation algorithm to segment the target area, extract the color information in the detection area, and construct a mathematical regression model by integrating these color channel feature parameters to quantitatively infer the iron concentration. The implementation process of the analysis algorithm is as follows: Figure 4 shown.

[0030] For actual outdoor measurements, the specific operations are as follows: After the sampling is completed, you must first open the tool and waste module of the equipment and take out the paper chips, micropipette guns, gun tips and other tools required for the measurement. Turn on the power switch of the equipment, and use a pipette to draw 25μL of sample from the sample reagent bottle according to the prompts on the screen and drop it on three of the paper chips on the PAD. Drop pure water on the remaining circular paper chip as a blank control. Then immediately put the PAD into the small drawer of the device and push it into the device, and press the "Start" button. At this time, an oxidation-reduction color development reaction occurs on the PADs, and the device will wait for 15 minutes. After the paper chip is fully colored, the test results will be displayed on the LCD screen. The specific operation process is as follows Figure 5 shown.

[0031] Specific methods

[0032] (1) The present invention adopts RK3399 development board as the main control module, and realizes one-touch operation of iron ion analysis through integrated analysis program;

[0033] (2) After pressing the power button to turn on the machine, the program displayed on the power-on interface is automatically executed, and the user can operate according to the interface on the LCD screen. After pressing the "Start" button, the image processing and analysis program is executed. First, the image acquisition part of the program is responsible for initializing the industrial camera, using the camera's MVGigE library to control the industrial camera to acquire 8-bit high-quality images, and store the images in the specified folder of the peripheral TF card;

[0034] (3) The image processing and analysis program reads the image just collected from the folder for preprocessing, feature extraction, and concentration analysis to obtain an accurate iron ion concentration value and jump to the result display interface;

[0035] (4) After the analysis process is completed, the command to obtain GPS will be executed, and then the analysis results and GPS data will be displayed on the LCD screen. Finally, the data backup program will be executed to upload the analysis results and related data to the Alibaba Cloud server in real time for backup.

[0036] The present invention combines machine vision technology and PAD colorimetry to measure the iron ion concentration in water. The device has a simple design, and the self-designed printed device shell increases the diversity of the device. The iron ion concentration can be measured without professional personnel. It has the significant advantages of low cost, simple operation, high detection efficiency, strong anti-interference ability, etc., and is suitable for Fe in natural water bodies. 3+ Rapid concentration detection.

[0037] The above description is only a specific implementation mode of the present invention. Any feature disclosed in this specification, unless otherwise stated, can be replaced by other equivalent or alternative features with similar purposes; all disclosed features, or all methods or steps in the process, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. A design method for a portable iron ion analyzer based on machine vision, characterized in that: The following steps are involved: Step 1: Design the overall structure and divide the portable iron ion analyzer into four modules: image information acquisition module, tool and waste module, power supply and control module, key interaction and display module. Among them, the image information acquisition module integrates an industrial CMOS camera and a ring LED white light source in a fully enclosed environment, thereby isolating external light interference and achieving reliable image acquisition. Below the camera and light source is a sliding drawer for placing PADs. The power supply and control module consists of an RK3399 development board and a lithium battery. The development board also integrates 4G and GPS for on-site positioning during measurement and securely backing up the measured data and coordinates. To facilitate on-site measurements, the analyzer also includes a tool and waste module, which can hold prepared PADs, disposable rubber gloves, micropipettes and tips, pure water for blank controls, and a waste storage compartment for discarded PADs and rubber gloves. The key interaction and display module includes two buttons and an LCD screen to facilitate user interaction throughout the measurement process; Step 2: Initialize the industrial camera, connect the industrial CMOS camera to the development board through the network port, use the camera's MV-GigE library function to write a Python program to control the industrial camera to collect 8-bit high-quality images, and store the images in the specified folder in the external TF card of the development board; Step 3: The development board reads the latest image collected in the folder and performs preliminary image preprocessing, including median filtering to reduce noise and using Hough transform to identify the ROI area. The color signal (including R, G, B, H, S, I, etc.) of the ROI area is extracted and used as input parameters to perform quantitative analysis of iron concentration through a multivariate regression model. Step 4: Use Python's PyQt5 graphical interface library to develop a graphical interface program, including the open_show startup interface display, the processing_show processing interface display, and the final result_show result interface display. The interfaces are all displayed by an LCD screen connected to the development board through the MIPI interface; Step 5: After executing the analysis process, design a program to obtain GPS commands, execute the data backup program, build an Alibaba Cloud server, obtain necessary information such as user name, password, SSH key, etc., and upload the analysis results and related data to the Alibaba Cloud server in real time for backup; Step 6: Use shapr3D software to design the device shell model, print the shell through 3D printing technology, deploy the hardware module to the corresponding position of the shell, and debug to achieve the effect.

2. The method according to claim 1, characterized in that: Step 1: Partition the entire device into four major functional modules, covering all the tools and devices required for measurement, providing convenience for on-site measurement.

3. The method according to claim 1, characterized in that: In step 5, Alibaba Cloud Server was built to achieve cloud backup of analysis results, location coordinates, and other information, ensuring data integrity and security.

4. The method according to claim 1, characterized in that: Step 6: Use shapr3D software to independently design and print the device's shell model, which increases the flexibility and variability of the device's appearance.

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