1、 Background of the plan

With the advancement of technology, IoT technology has quietly entered our lives and work, and has been applied in various fields. Things such as hydrology and water conservancy, industrial monitoring, smart cities, smart water management, etc. are connected to cloud servers through the Internet of Things, which improves production efficiency, flexibility, and responsiveness through big data analysis and processing.

The products originally used for measuring temperature, pressure, flow rate, and level in industry have also been directly transplanted to municipal applications through the early direct matching of corresponding components or fast modeling. Now, with the deep research and development of built-in communication chips, low-power design, dedicated power management solutions, and automatic sleep technology, the specialized sensing end IoT products designed for the characteristics of municipal applications are truly suitable for current practical applications.

With the continuous advancement of cloud services and related technologies, significant progress has also been made in supporting remote monitoring. It is possible to quickly obtain relevant data and have a clear understanding of various parameters using mobile apps, WeChat mini programs (which can cross mobile operating systems, even the recently popular HarmonyOS), IE, and other means.

In the application of hydrological and municipal measuring instruments, alternative technologies have continuously emerged in China in recent years, leading to an increasing use of new technologies in hydrological observation. The application of ATV acoustic tomography with large cross-sections, as well as the extensive use of various types of acoustic, optical, and electrical equipment. Keeping hydrological and municipal observations in sync with contemporary technology.

2、 Scheme Introduction

Autai Automation Remote Inland River ADV Doppler Flow Measurement Solution: Convenient data collection, processing, and orderly remote observation of hydrological data, including smooth flow velocity, elevation water level, water temperature, smooth flow rate, net cumulative flow rate, discharge area, inverted flow velocity, inverse flow rate, peak flow velocity, peak flow rate, forward accumulation, reverse accumulation, etc. It can also be set with installation height, smoothness coefficient, reverse flow switch, installation angle, flow shape and parameters, accumulation reset, baud rate, address, etc.

The ADV ultrasonic Doppler flowmeter product from Aotai Automation is suitable for monitoring water level, flow velocity, and flow rate in rivers, oceans, observation stations, ships, buoys, open channels, sewage outlets, municipal pipelines, and other occasions. It is also suitable for simulating flow velocity and tidal power sources in the laboratory, as well as for flow measurement applications in conjunction with cable systems.

2.1 Measurement principle

Doppler ultrasonic flowmeter brings you professional service,the flow velocity measurement of this product is based on the principle of acoustic Doppler effect: when ultrasonic waves are incident on water, scattering bodies (such as suspended particles, bubbles, microorganisms) in the water scatter the sound waves. Due to the presence of water flow, there is relative motion between the scattering bodies and the transmitter and receiver, and the received signal has a certain frequency offset relative to the transmitted signal, which is the Doppler frequency shift. The frequency shift value is related to the flow velocity.

According to the Doppler shift equation, the magnitude of the frequency shift is:

The ultrasonic emission frequency is constant, and the angle of the transducer is fixed after installation, so K is constant. From equation ③, it can be seen that the flow velocity V is proportional to the Doppler frequency shift △ Fd and the sound velocity C of water. As long as the Doppler frequency shift △ Fd and the sound velocity C of water are detected, the flow velocity can be calculated. In this instrument, C is converted from temperature values.

The schematic diagram of the sound field is shown below:

2.2 Output Modes

The output methods usually include: 4G, NB-IOT, RS485, etc

4G: It needs to be paired with a host, fully connected to the internet, and can be adapted to China Telecom, China Unicom, and China Mobile. With good signal coverage, it is the first choice for communication methods. The disadvantage is that it has higher power consumption than NB and better overall cost-effectiveness;

NB-IOT: It needs to be paired with a host. Due to good signal coverage, with China Telecom being the most common, it has stable performance, low power consumption, and is relatively reliable for application in urban areas. It is currently one of the most widely used modes;

RS485 signal: It is common to directly use the original industrial instrument's 485 signal in the early days, which can be matched with a general RTU for actual transmission. Advantages: easy to connect, disadvantages: high power consumption, poor protocol integration.

2.3 Power supply mode

Usually powered by built-in batteries, external batteries, solar power, and mains power (220VAC):

Built in battery power supply: usually operates intermittently, mainly with built-in lithium batteries, especially lithium-ion batteries, which have outstanding self discharge performance and are suitable for long-term endurance. There are also built-in rechargeable batteries, but this technology level is relatively backward. At the same time, due to the poor self discharge performance of these batteries, they are only used in short-term emergency work scenarios, such as 1-2 months or even 1-2 weeks of work. This type of pattern requires a high level of product design skills;

External battery power supply: usually operates intermittently, with an external battery pack that can be rechargeable or non rechargeable, with 3.6V and 12V options available;

Doppler ultrasonic flowmeter brings you professional service,solar power supply: It usually works continuously and provides reliable power supply. It can work continuously without interval, which is a major advantage over the previous two methods. Continuous measurement ensures the measurement of particle size, but currently many installation points cannot meet the landscape requirements and require high investment (power supply system: solar panels, controllers, batteries, electrical cabinets, poles, etc.);

220VAC mains power: usually connected to equipment through a 12VDC DC power supply.

2.4 Technical Features

(1) Power supply: 8-16VDC;

(2) Signal output: RS485, MODBUS, RTU;

(3) Compact in size, with a small flow surface and a streamlined shape, it has little impact on the flow state;

(4) The first three points of quick installation can be adapted to manufacturer specific brackets, and various types of brackets can be freely processed;

(5) Single point single wave speed underwater sonar (2M);

(6) Ultrasonic transducer: separation of transmitter and receiver;

(7) Optional built-in conductivity sensor, sensing water quality from 0-10mS/cm, bidirectional measurement with positive page number -5 to+5m/s;

(8) High precision, wide range, bidirectional measurement, sensitive induction, high resolution;

(9) Fast response speed, can measure instantaneous flow velocity, as well as invert flow rate and smooth flow velocity;

(10) Measuring linearity;

(11) There are no mechanical rotating parts, and there are no issues such as mud blockage or entanglement of water, grass, or debris;

(12) Suitable for measuring various water bodies with high sediment and suspended solids content, as well as for unmanned long-term automatic online monitoring;

(13) The application of underwater phase acoustic control technology makes the system measurement more stable;

(14) The waterproof cable with air guide makes water level measurement more accurate, and the anti bending cable connector makes the equipment straight and safer.

2.5 Platform

The data processing software integrates the uploaded data and can display the current data of each measuring point, forming historical data and curves. It can also form reports of data from any time period, print data, and view data from any device through mobile WeChat programs, facilitating the diversity of monitoring. It can also set various parameter alarm functions (voice calls, SMS, etc., which require recharging communication and telecommunications fees on the platform).

2.6 Problem solving

The product not only meets the requirements of conventional measurement, but also solves the problem that ordinary flow measuring equipment cannot be used in low water levels, low flow rates, high sediment content, and numerous aquatic plants. Monitoring the water flow data in urban inland rivers, drainage pipelines, farmland irrigation channels, and non full pipelines can help accurately evaluate the operation of pipelines and improve the management and operation level of drainage systems.

3、 Product Function Description

3.1 Technical parameters of ADV Doppler sensor

Technical parameters:

(1) Flow velocity measurement range: 0-10.00m/s, -5-5.00m/s (bidirectional flow); (Can be specially customized)

(2) Flow velocity accuracy: 1% ± 0.01 m/s; Resolution: 0.001 m/s;

(3) Dead zone velocity: 0001~0.006 m/s

(4) Water temperature measurement range: -5 ℃ to 60 ℃;

(5) Accuracy of water temperature: ± 0.5 ℃;

(6) Water level range: 0-10m; (can be specially customized)

(7) Water level accuracy: 0.2% ± 1mm. Low water level can measure 20mm;

(8) Sensor: single point single beam, 2MHz, 25 ° tilt angle;

(9) Waterproof rating: Sensor IP68, Host IP65 (IP68 can be specially customized);

(10) Storage temperature: -20 ℃ to 60 ℃;

(11) Output interface: RS485, MODBUS, RTU;

(12) Power supply: 8-16VDC;

(13) Measurement parameters: Smooth flow velocity, inverted flow velocity; Elevation water level, water passage area; Water temperature, sound velocity;

(14) Response time: 1-60 seconds, factory default: 5 seconds.

External dimensions:

3.2 Host Technical Parameters

Technical Parameter

(1) Power supply: 8-16VDC;

(2) Structure: Split wall mounted;

(3) Usage conditions: IP65; Suggested environmental temperature: 0~50 ℃; Suggested relative humidity: 90% RH; (IP68 can be specially customized);

(4) Resolution: 1mm;

(5) Calculation of overflow area: rectangle, trapezoid, circle, ellipse, U-shape, custom (base elevation);

(6) Input characteristics: ADV Doppler flow velocity sensor;

(7) Output features: 4G wireless output, NB-IOT (not standard);

(8) Through remote settings (computer, mobile phone): IP address, port, transmission interval, sleep time and other parameters;

(9) Support OTA remote upgrade.

External dimensions: