A buoy-type remote mobile monitoring system and method for lake water quality

Abstract

The present invention discloses a buoy-type remote mobile monitoring system and method for lake water quality, which consists of a remote control center and multiple mobile monitoring devices. The remote control center includes a main control unit, a motor control module, a mechanical transmission control module, a sensing unit, a data transmission unit, and a monitoring data processing and display module. As an intelligent monitoring system based on the Internet of Things environment, the present invention utilizes the online monitoring function, communication function, and big data processing function of the Internet of Things to monitor the parameter changes of water quality in the lake in real time, and to feedback the pollution degree of the lake water in real time, realizing the integration and intelligence of water quality monitoring.

Description

Technical Field

[0001] The present invention relates to the technical field of remote on-line monitoring of water environment, and particularly to a movable buoy type water quality on-line monitoring system for remote on-line monitoring of lake water quality and an integrated implementation scheme thereof. Background Art

[0002] The monitoring and treatment of water quality are important means to adhere to the path of sustainable development. Taking lakes as an example, compared with the ecosystem of cross-flowing rivers, their self-regulating ability is much weaker. Especially in urban parks and other densely populated areas, which accommodate the lives of thousands of people, it brings more uncertainties to the water quality of lakes. Many traces of human activities may affect the water quality of lakes. For example, randomly discarded garbage can be blown into the water by the wind to affect the water quality, overfeeding aquatic organisms will enrich the nutrients in the water, and haze and dust will affect the turbidity of the water. The interweaving of human factors and natural environmental changes makes it necessary to monitor the water quality of lakes for their protection.

[0003] The existing water quality monitoring systems are mainly designed for long-term automatic monitoring of water quality at fixed positions based on wireless communication networks, and the current wireless network water quality monitoring technology is mainly used for data transmission between electronic devices with short action distances and low transmission rates. In addition, compared with the traditional water quality monitoring systems, although the existing remote water quality monitoring systems have greatly improved in terms of efficiency, functions, etc., there are still problems such as small water quality detection range, low accuracy, and insecure data transmission. Summary of the Invention

[0004] In view of the deficiencies of the above related technologies, the present invention proposes a buoy type remote lake water quality mobile monitoring system and method, and designs the remote monitoring device to be freely movable, so as to realize real-time mobile monitoring of the water quality conditions of multiple predetermined areas.

[0005] The present invention is realized by the following technical solutions:

[0006] A buoy type remote lake water quality mobile monitoring system, which is composed of a remote control center and a plurality of mobile monitoring devices; wherein:

[0007] The remote control center includes a main control unit, a motor control module, a mechanical transmission control module, a sensing unit, a data transmission unit, and a monitoring data processing and display module. Among them, the motor control module is connected to the main control unit and is freely controlled by the main control unit. The motor control module further controls the mechanical transmission control module, and the mechanical transmission control module controls the sensing unit to achieve free movement for collecting various water quality parameters. The sensing unit at least includes various water quality parameter sensors, a water quality COD detector, a voltage sensor, and a position sensor. The sensing unit transmits the collected data of various water quality parameters to the data transmission unit. The data transmission unit is connected to the water quality data collection module through a wireless network, and the water quality data collection module is connected to the monitoring data processing and display module.

[0008] The mobile monitoring device is divided into three parts: the upper part of the support plate, the support plate, and the lower part of the support plate. Among them, the upper part of the support plate is a lid, and the lower part of the support plate is provided with two buoys, a deflector, and two sets of mechanical transmission components. A water quality detection digital sensor and a water quality COD detector are placed on the support plate.

[0009] The structure of each set of the mechanical transmission components further includes a reduction gear set and a bevel gear set arranged between a DC brushless motor and a propeller, a transmission shaft, and an output shaft. Among them, the reduction gear set includes a pair of spur gears, namely a large spur gear and a small spur gear. The bevel gear set is a pair of bevel gears, and the bevel gear set is arranged in a gear box, namely a first bevel gear and a second bevel gear. Among them, the large spur gear and the first bevel gear are installed on the transmission shaft, and the propeller and the second bevel gear are installed on the output shaft. The thrust generated by the propeller is transmitted to the gear box to drive the transmission of the bevel gear set. The small spur gear is installed on the motor shaft of the DC brushless motor. The DC brushless motor is arranged in a motor box, and the motor box is arranged below the reduction gear set and above the support plate. The output shaft is horizontally arranged, and the transmission shaft is vertically arranged.

[0010] A buoy-type remote lake water quality mobile monitoring method, which includes the following steps:

[0011] Use the main control unit of the remote control center to send control commands to perform overall function control on the motor control module, the mechanical transmission control module, the sensing unit, the data transmission unit, and the monitoring data processing and display module.

[0012] Use the motor control module to achieve free control of the motor shaft, thereby controlling the mechanical transmission control module.

[0013] Use the mechanical transmission control module to control the sensing unit to achieve free movement for collecting various water quality parameters.

[0014] The water quality data is collected by various water quality sensors in the sensing unit and transmitted to the data transmission unit;

[0015] The data transmission unit is used to transmit the data collected by the sensors to the cloud server. The PC side processes the data by using Niagara software, and the data processing file is uploaded to the network. The real-time observation of the data changes of each water quality parameter is realized through the monitoring data processing and display module.

[0016] Compared with the prior art, the present invention utilizes the online monitoring function, communication function and big data processing function of the Internet of Things to monitor the parameter changes of the water quality in the lake in real time, and feedback the pollution degree of the lake water in real time, realizing the integration and intelligence of water quality monitoring; and various methods for improving the detection performance are proposed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the mobile monitoring device of the present invention; (1a) front view, (1b) sectional view, (1c) side view;

[0018] Figure 2 It is a schematic diagram of the structure of the lid; (2a) front view, (2b) bottom view;

[0019] Figure 3 It is a schematic diagram of the structure of the buoy;

[0020] Figure 4 It is a schematic diagram of the structure of the baffle; (4a) front view, (4b) full sectional view of the left view, (4c) bottom view;

[0021] Figure 5 It is a schematic diagram of the structure of the support plate; (5a) front view, (5b) sectional view;

[0022] Figure 6 It is a schematic diagram of the structure of the mechanical transmission component; (6a) front view, (6b) sectional view;

[0023] Figure 7 It is a schematic diagram of the structure of the gear box; (7a) front view, (7b) schematic diagram of the right half of the gear box; (7c) top view;

[0024] Figure 8 It is a schematic diagram of the structure of the transmission shaft; (8a) front view, (8b) left or right view;

[0025] Figure 9 It is a schematic diagram of the structure of the output shaft; (9a) front view, (9b) left or right view;

[0026] Figure 10 It is a module diagram of the remote control center of the present invention;

[0027] Figure 11 It is a calibration flow chart for measuring the COD parameter under the interference of suspended matter based on the clustering method;

[0028] Figure 12 It is a flow chart for improving the detection performance of the COD parameter based on the monitoring of the light source stability;

[0029] Figure 13 It is a flow chart for the failure mechanism of the water quality COD detector caused by the pollution of the optical window and the corresponding method for improving the service life.

[0030] Reference numerals:

[0031] 1. Alarm lamp, 2. Lid, 3. Support plate, 4. Trapezoidal groove, 51, 52. Buoy, 6. Deflector, 71, 72. Propeller, 8. Mechanical transmission component, 9. Second bevel gear, 10. Positioning rubber ring, 11. Propeller connecting piece, 12. Second waterproof shaft sleeve for ship model, 13. Shaft sleeve support flange, 14. Second angular contact ball bearing, 15. Output shaft, 16. Second positioning shaft sleeve, 17. First bevel gear, 18. First positioning shaft sleeve, 19. First angular contact ball bearing, 20. Transmission shaft, 21. Gear box positioning screw, 22. First positioning rubber ring, 23. First waterproof shaft sleeve for ship model, 24. Motor box, 25. Large spur gear, 26. Small spur gear, 27. Motor box cover screw, 28. Motor box cover, 29. DC brushless motor, 30. Isolation cover, 31. Screw, 321 - 330. Threaded hole, 33. Central through hole, 34. Solar panel, 35. Through hole, 36. Gear box, 37. 6-parameter water quality sensor, 38. Water quality COD detector, 39. First bevel gear mounting hole, 40. Large spur gear mounting hole, 41. Second bevel gear mounting hole. Specific implementation mode

[0032] To further elaborate on the technical solutions and features of the present invention, the technical solutions of the present invention are used below to take a pumped-storage power station project as an example for detailed description, but the content of the present invention is not limited to the content described in the specific embodiments.

[0033] As Figure 1 shown, it is an overall structural schematic diagram of a movable buoy type remote lake water quality monitoring device of the present invention. The whole of this device is divided into three parts: the upper part of the support plate, the support plate 3, and the lower part of the support plate. This structural design is also to facilitate the solar panel to be more easily irradiated by the sun. Among them, the upper part of the support plate is the lid 2. The alarm lamp 1 is placed on the top of the lid 2, and a central hole 33 is opened as a channel for positioning the alarm lamp and its power cord. The overall material of the lid 2 is plastic, and 4 trapezoidal grooves 4 are drilled through on its four-sided inclined surface to facilitate the placement of the solar panel 34. Two buoys 51, 52 and a deflector 6 are arranged at the lower part of the support plate 3.

[0034] As shown Figure 2 in the figure, it is a schematic structural diagram of the lid; (2a) front view, (2b) bottom view. In order to fix the lid 2 to the support plate 3, 4 threaded holes 321-324 are drilled at the four corners of the lid respectively. Specifically, the inside of the lid 2 is shelled, and the wall thickness is 5 mm.

[0035] As shown Figure 3 in the figure, it is a schematic structural diagram of the buoy. The buoys 51 and 52 are the buoyancy sources of the entire device on the water surface. The material is selected as rigid sponge, and there is a smooth waterproof layer on the surface, which can meet the buoyancy requirements of the entire device. 2 threaded holes 325 and 326 are drilled on each buoy for fixing to the support plate 3.

[0036] As shown Figure 4 in the figure, it is a schematic structural diagram of the flow guide plate; (4a) front view, (4b) full sectional view of the left view, (4c) bottom view. The flow guide plate is made of plastic and has a certain buoyancy, providing additional buoyancy for the entire device. Moreover, through the flow guide plate, the entire device can more easily achieve straight driving in water and still be able to turn when the driving speed is relatively fast, so as to disperse the water resistance.

[0037] As shown Figure 5 in the figure, it is a schematic structural diagram of the support plate; (5a) front view, (5b) sectional view. The support plate 3 bears various electrical components, internal components and external components on the board, and is connected to the buoy, the flow guide plate and mechanical transmission related components below. The material is selected as aluminum alloy with high strength, corrosion resistance and light weight. A central through hole 33 is drilled in the center of the support plate for placing the water quality detection digital sensor. Another through hole 35 is opened on the same axis for placing the water quality COD detector 38. The remaining required special-shaped holes are determined by the needs of the other parts of the system.

[0038] As shown Figure 6 in the figure, it is a schematic structural diagram of the mechanical transmission component; (6a) front view, (6b) sectional view. The mechanical transmission component 8 includes a reduction gear set and a bevel gear set, a transmission shaft 20 and an output shaft 15 arranged between the DC brushless motor 9 and the propeller 7. Among them, the reduction gear set includes a pair of spur gears, namely the large spur gear 25 and the small spur gear 26; the bevel gear set is a pair of bevel gears, namely the first bevel gear 17 and the second bevel gear 9; the large spur gear 25 and the first bevel gear 17 are installed on the transmission shaft 20, and the propeller 7 and the second bevel gear 9 are installed on the output shaft 15; the bevel gear set is arranged in the gear box 36; the thrust generated by the propeller 7 is transmitted to the gear box, driving the transmission of the bevel gear set. The small spur gear 26 is installed on the motor shaft of the DC brushless motor 29.

[0039] Since the motor speed can be freely controlled, for the convenience of calculation, the reduction ratio of the reduction gear set is set to 2:1, and the transmission ratio of the bevel gear set is set to 1:1. The module of the straight bevel gear is selected as 1, and the pressure angle is 20°.

[0040] The DC brushless motor 29 is arranged in the motor housing 24, and the motor housing 24 includes a motor cover 28, which is fixedly connected to the motor housing 24 by motor cover screws 27.

[0041] Specifically, the function of the bevel gear set is to change the transmission direction of the torque. Therefore, the number of teeth of the two gears can be selected to be equal, that is, the number of teeth of the 2 bevel gears is selected to be 20. On the premise of the unchanged number of teeth, the smaller the module, the smaller the gear size. Therefore, considering meeting the functional requirements, a space-saving design is made as much as possible.

[0042] In order to realize the function of freely moving on the water surface by wireless control. The present invention uses a motor to drive a propeller as the driving force, and controls the device to move forward, backward and turn to realize free movement on the water surface.

[0043] The total size of the water quality monitoring system is 840mm * 840mm * 755mm, and the vertical cross-sectional area S of the deflector d = 0.117m 2 , and the overall weight is between 25 kg and 30 kg. It moves by two motors respectively driving a propeller to rotate to generate thrust, as shown in component 7 in Figure 1 . When turning is required during driving, the two propellers work in a differential mode, so there are high requirements for the control of the motor. Considering the rationality of the overall structure, a 100mm large-thrust three-blade nylon propeller is selected. The blade diameter D is 100mm, the hub diameter d is 13mm, the hub height H is 33mm, the width b of the card slot is 4.3mm, and the depth h of the card slot is 3mm. The transmission scheme is a straight-tooth reduction gear plus bevel gear transmission to achieve the purpose of reducing speed and transmitting torque to the propeller.

[0044] As Figure 7 shown, it is a schematic structural diagram of the gear housing; (7a) front view, (7b) schematic diagram of the right half of the gear housing; (7c) top view. Among them, the overall size of the gear housing is 80mm * 50mm * 110mm. For the convenience of processing, it is divided into left and right parts. Except for the different holes connecting the two parts, the other structures of the two parts are the same. Four M6 threaded holes 327 - 330 are drilled at the top of the gear housing and connected by screws and the support plate 3. The holes connecting the left and right parts are Φ6 through holes on the left part and M6 threaded holes on the right part.

[0045] As Figure 8 shown, it is a schematic structural diagram of the transmission shaft; (8a) front view, (8b) left or right view;

[0046] At both ends of the transmission shaft, a first bevel gear mounting hole 39 and a large spur gear mounting hole 40 are respectively provided. The transmission shaft is vertically arranged. In addition to bearing radial forces, it also bears axial forces through the provided angular contact ball bearings. The aperture sizes of the large spur gear and the bevel gear have been determined to be 6 mm. In order to facilitate processing, it is decided to reduce the design of the stepped shaft and specify the inner diameter of the angular contact ball bearing to be 6 mm. Specifically, a miniature high-speed precision 719 / 6c angular contact ball bearing can be selected, with a dimension specification of 6 mm * 15 mm * 5 mm (inner diameter * outer diameter * thickness). This miniature bearing has a small size and smooth transmission.

[0047] In order to ensure that the thrust generated by the rotation of the propeller is not affected by the support plate, the transmission shaft should be appropriately lengthened so that the propeller is far from the support plate. Since the bearing is inconvenient to be installed on the shaft section above the support plate, a segmented treatment method is adopted to solve this problem. For the shaft section in the gear housing, a pair of angular contact ball bearings are installed in reverse to support the rotation of the shaft and bear part of the radial force and all of the axial force; for the shaft section above the support plate and above, a mature shaft sleeve for ship models is adopted. This type of shaft sleeve is filled with lubricating oil inside and has sealing measures at both ends, which can reduce the friction between the shaft sleeve and the shaft and play a role similar to that of a deep groove ball bearing, bearing radial forces and improving the stability of gear transmission.

[0048] The entire shaft is made of 304 stainless steel. The installation distance between the large spur gear and the coaxial bevel gear is 153 mm, the distance between the two positioning shoulders is 45 mm, and the shoulders are used for bearing positioning. The total length of the shaft is 174 mm.

[0049] As Figure 9 shown, it is a structural schematic diagram of the output shaft.

[0050] A second bevel gear mounting hole 41 is provided at one end of the output shaft. The output shaft is horizontally arranged and needs to bear radial forces when transmitting torque. Since axial forces are generated by bevel gear transmission and the thrust generated by the propeller also acts axially, angular contact ball bearings are still selected. The inner diameter of the bearing on the output shaft is specified as 5 mm, and a miniature high-speed precision 719 / 5c angular contact ball bearing is selected, with a dimension specification of 5 mm * 13 mm * 4 mm (inner diameter * outer diameter * thickness). Similarly, the shaft is segmented. For the shaft section in the gear housing, a pair of angular contact ball bearings are installed in reverse to support the rotation of the shaft and bear part of the radial force and all of the axial force; for the shaft section outside the gear housing and in contact with water, a shaft sleeve for ship models is used to support the rotation of this part of the shaft. This type of shaft sleeve is filled with lubricating oil inside and has waterproof sealing rings at both ends, with good waterproof performance.

[0051] The entire shaft is made of 304 stainless steel. Since a part of the output shaft works in water, a too long shaft design will increase power loss and reduce the stability of torque transmission, while a too short design will be affected by turbulent flow because the propeller is too close to the gear box, resulting in insufficient thrust. Considering the above factors, the installation distance between the propeller and the bevel gear is determined to be 80 mm, the distance between the two positioning shaft shoulders is 8 mm, and the length of the entire shaft is 114 mm.

[0052] As Figure 10 shown, it is an overall framework diagram of a buoy-type remote lake water quality mobile monitoring system. The system includes a main control unit 110, a motor control module 120 controlled by the main control unit 110, a mechanical transmission control module further controlled by the motor control module, a sensing unit 140 that performs free displacement controlled by the mechanical transmission control module. The sensing unit 140 further includes various water quality parameter sensors, a water quality COD detector, a voltage sensor, and a position sensor. The sensing unit is connected to a data transmission unit (DTU) 150, and the data transmission unit 150 is connected to a water quality data acquisition module 170 through a wireless network 160, and the water quality data acquisition module 170 is further connected to a monitoring data processing and display module 180.

[0053] In practical applications, the system is an intelligent monitoring system based on the Internet of Things environment. The solar panel and the lithium battery provide energy for the entire physical system. Various sensors are responsible for data collection. The data transmission unit transmits the data collected by the sensors to the cloud server. The PC side uses Niagara software to organize and edit the data, and uploads the edited file to the network. Through mobile phones, tablets or computers, the data changes of various water quality parameters can be observed in real time. The data transmission unit selects DTU, which is a wireless terminal device used to convert serial data into IP data or convert IP data into serial data and transmit it through a wireless communication network. The system can also provide cloud services by setting up a server.

[0054] The specific implementation of a buoy-type remote lake water quality mobile monitoring system of the present invention is described as follows:

[0055] 1. Application layer:

[0056] The present invention uses the Niagara platform as the server-side application development framework. Niagara is a mature operating system in the Internet of Things field, integrating device management, connection management, application development, system and software development. Its modular modeling method can greatly improve the system development efficiency. A complete Internet of Things application based on Niagara usually requires three levels of configuration, namely the driver layer, the background logic layer, and the front-end display layer. At the driver layer, a point-to-point correspondence is established between Niagara and the sensors, including seven parameters such as water quality pH value, conductivity, dissolved oxygen, chemical oxygen demand (COD), ammonia nitrogen, turbidity, and temperature, as well as the remaining battery power parameter of the lithium battery and the longitude and latitude parameters of the device. The driver layer is the bridge for data exchange between the device side and the software side. The background logic layer mainly realizes the construction of the logical framework from sensor data to the front-end display controls, such as the conversion of sensor data, schedule setting, alarm setting, and the connection between data points. The background logic layer can achieve complex logical orchestration, equivalent to the "nerve center" of the entire monitoring system. The front-end display layer provides the human-computer interaction interface of the system, mainly divided into three major functional areas, namely the instrument display area, the alarm viewing area, and the historical statistics area. In the instrument display area, the most commonly used water quality parameters are presented in the form of instrument modules, making the water quality data clear at a glance. The alarm viewing area is used to display the latest water quality parameter alarm data. When a certain water quality parameter exceeds the set threshold, the system automatically generates an alarm. The historical statistics area contains historical curves and historical statistical charts, which can help managers understand the changes in relevant water quality parameters.

[0057] 2. Network Layer

[0058] To ensure smooth communication between the sensors at the monitoring site and the remote server and achieve remote real-time monitoring of water body quality, the present invention has established a data communication network ([ Figure 3 ) with the data transmission unit (DTU) as the core. A 485 bus is established inside the device, and each communication unit is hung on the bus. Among them, the DTU is responsible for converting the serial port data to the 4G wireless network, enabling the system to access the Internet. The server working remotely receives the real-time data transmitted by the monitoring system, which serves as the basis for subsequent big data analysis and decision-making. The communication between each monitoring system is completed through the Modbus protocol. Inside the system, the Modbus RTU protocol is used between the sensor and the DTU. The DTU module assigns a unique Modbus RTU address to each sensor to avoid communication conflicts. On the Internet, the Modbus TCP protocol is used between the server and the DTU, and the DTU realizes the protocol conversion from Modbus RTU to Modbus TCP here. In addition, the DTU also configures a Modbus TCP port number corresponding to each sensor with a unique Modbus RTU address, so that the server can distinguish each sensor.

[0059] The present invention also proposes a solution for improving the COD sensing and detection performance, which is specifically described as follows:

[0060] (1) Calibrating the measurement of COD parameters under the interference of suspended matter based on the clustering method:

[0061] The method adopted by existing research to eliminate the interference of suspended matter in water is to measure the concentration of suspended matter using the absorbance at other wavelengths and remove the measurement result from the measurement result of COD parameters. However, the problem with such methods is that the anti-interference algorithm is single. For different water bodies, the influence law of suspended matter on COD is different, resulting in the failure of the anti-interference algorithm. The present invention constructs a characteristic state space of water body suspended matter and colloid using turbidity and COD parameters, and establishes a clustering analysis model for various typical water bodies, so as to obtain the influence law of the concentration of inorganic substances such as suspended matter and colloid in the water body sample on the COD parameter detection performance. On this basis, a targeted anti-interference algorithm is designed to improve the robustness of the sensor.

[0062] As Figure 11 shown, it is a calibration flow chart for calibrating the measurement of COD parameters under the interference of suspended matter based on the clustering method. This process specifically includes: according to the sample requirements, simulating water quality samples of various typical water bodies at different suspended matter concentrations to obtain typical water body water quality samples, and using a spectral analyzer to obtain the corresponding spectral data; measuring the absorbance of the same water quality sample under different light source radiation intensities, and calculating the turbidity and COD parameter values as the uncalibrated COD parameter values; constructing a characteristic state space with the true values of turbidity and COD parameters as the characteristic dimensions, and performing clustering analysis on the above samples to establish a characteristic database of suspended matter in typical water body samples; using the CODMn method to measure the true values of COD parameters of each typical water body water quality sample according to the interference law of suspended matter (such as inorganic substances such as water body suspended matter and colloid); by comparing the uncalibrated COD parameter values and the true values of COD parameters one by one, analyzing the interference intensity of water body suspended matter for each category, and proposing corresponding calibration algorithms to improve the monitoring accuracy of the sensor.

[0063] (2) A method for improving the COD parameter detection performance based on the monitoring of light source stability

[0064] As Figure 12As shown in the figure, it is a flow chart for improving the detection performance of COD parameters based on the monitoring of light source stability. Measuring the radiation intensity of the light source includes measuring the luminous intensity of the light source from the first use to failure and the radiation intensity of the light source under different supply voltages; establishing a performance degradation curve for the entire life cycle of the light source to obtain the fluctuation range of the radiation intensity of the light source; then, obtaining typical water quality samples, measuring the absorbance of the same water quality sample under different radiation intensities of the light source, and after fitting using the least squares method, obtaining the curve of the absorbance varying with the radiation intensity of the light source. Through comprehensive analysis of the varying curves of multiple typical water bodies, summarizing the influence law of the degradation of light source stability on the detection performance of COD parameters, and proposing corresponding correction algorithms, so as to improve the life of the sensor.

[0065] (3) Failure mechanism of water quality COD detector caused by optical window pollution and corresponding life improvement method:

[0066] As Figure 13 shown in the figure, it is a flow chart for the failure mechanism of water quality COD detector caused by optical window pollution and the corresponding life improvement method. Establish an evaluation standard for the pollution of the optical window of the sensor probe, and conduct quantitative analysis on indicators such as the pollution area and pollution degree, that is, conduct quantitative analysis of the optical window pollution; for each quantitatively polluted state of the optical window, conduct COD parameter detection by COD-UV method (that is, ultraviolet-visible spectrophotometry, used to evaluate the degree of pollution of water bodies by these organic substances) and CODMn method detection (referring to under certain conditions, oxidizing some organic substances and inorganic oxidizable pollutants in water with potassium permanganate, and calculating the equivalent chemical oxygen demand from the consumed potassium permanganate), obtain the corresponding detection deviation, and conduct detection deviation analysis; change the optical path length (set different optical path lengths of the absorption cell), measure the detection deviation respectively according to this method, and conduct detection deviation analysis, so as to obtain a data set containing optical window pollution information. The establishment process of the data set is as follows: test the water quality samples under different optical path lengths of the absorption cell through COD-UV method detection and CODMn method detection to obtain the original data, and then obtain the detection deviation data through deviation analysis. The original data and the detection deviation data together constitute the entire data set; establish a response surface model, analyze the correlation between optical window pollution and detection deviation, establish an anti-pollution correction algorithm for the optical window of the corresponding sensor probe, improve the tolerance of the sensor to probe pollution, and thus reduce the maintenance frequency of the sensor.

[0067] The rationality of the mechanical transmission module is verified through calibration calculation, the feasibility of the motor control module is verified through Proteus simulation experiment, and the effectiveness of the data communication module is verified through actual communication test. The comprehensive experimental results show that this design has completed the preset goal, can realize the function of remotely controlling the water quality monitoring system in the school lake to move freely on the water surface, and can dynamically monitor the water environment quality of the lake in real time.

Claims

1. A buoy-type remote lake water quality mobile monitoring method, It is characterized in that The method comprises the following steps: The calibration process of COD parameter measurement under suspended matter interference is realized based on clustering method. The process specifically includes: according to sample requirements, water quality samples of various typical water bodies under different suspended matter concentrations are simulated to obtain typical water quality samples, and corresponding spectral data are obtained; absorbance measurement is performed on the same water quality sample under different light source radiation intensities, and turbidity and COD parameter values ​​are calculated as uncalibrated COD parameter values; a feature state space with the true values ​​of turbidity and COD parameters as feature dimensions is constructed, and cluster analysis is performed on the above samples to establish a typical water sample suspended matter feature database; the CODMn method is used to measure the true value of COD parameters of each typical water quality sample according to the suspended matter interference law; the interference intensity of suspended matter in each category of water is analyzed by comparing the uncalibrated COD parameter value with the true value of COD parameter, and a corresponding calibration algorithm is proposed to improve the monitoring accuracy of the sensor; The COD parameter detection performance improvement process based on light source stability monitoring specifically includes: measuring the radiation intensity of the light source, including measuring the luminous intensity of the light source from the first use to the failure of the light source and the radiation intensity of the light source under different power supply voltages; establishing the performance degradation curve of the light source throughout its life cycle to obtain the fluctuation range of the radiation intensity of the light source; then, obtaining typical water quality samples, measuring the absorbance of the same water quality sample under different light source radiation intensities, and obtaining the variation curve of absorbance to light source radiation intensity after fitting using the least squares method. Through comprehensive analysis of the variation curves of multiple typical water bodies, the influence of light source stability degradation on COD parameter detection performance is summarized, and a corresponding correction algorithm is proposed to achieve the improvement of the life of the sensor; The invention includes the failure mechanism of water quality COD detector from optical window pollution and the corresponding life extension method process, which specifically includes: establishing the optical window pollution evaluation standard of the sensor probe, and conducting quantitative analysis on indicators including pollution area, pollution degree, etc., that is, conducting quantitative analysis on optical window pollution; conducting COD-UV method detection and CODMn method detection on the COD parameters under each quantified optical window pollution state, obtaining the corresponding detection deviation, and conducting detection deviation analysis; changing the optical path length, measuring the detection deviation, and conducting detection deviation analysis, so as to obtain a data set containing optical window pollution information; establishing a response surface model, analyzing the relationship between optical window pollution and detection deviation, establishing the corresponding anti-pollution correction algorithm for the optical window of the sensor probe, improving the sensor's tolerance to probe pollution, and thus reducing the maintenance frequency of the sensor.

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