CN204346544U - A kind of wireless ultrasonic water-level gauge - Google Patents

Abstract

A wireless ultrasonic water level gauge, comprising a column (1) arranged on the side of the water surface, the column (1) protruding forward is provided with an instrument box (2), and the bottom of the instrument box (2) is provided with an ultrasonic sensor (5) and a temperature sensor (4), the top of the instrument box (2) is provided with a radio frequency antenna (3), a reference baffle is fixed between the probe of the ultrasonic sensor (5) and the water surface, the inside of the instrument box (2) is provided with a CC2430 chip, and the CC2430 chip The input end is connected with the ultrasonic sensor (5) and the temperature sensor (4), the output end is connected with the radio frequency antenna (3), and the CC2430 chip adopts Zigbee technology to connect with the host computer through the radio frequency antenna. The water level gauge adopts air-mediated measurement method, which integrates data collection, storage and transmission. The wireless transmission adopts Zigbee technology, which not only has high measurement accuracy, but also low power consumption, reliable data transmission, and reduces infrastructure investment.

Description

A wireless ultrasonic water level gauge

Technical field:

The utility model relates to a water level gauge, in particular to a wireless ultrasonic water level gauge.

Background technique

At present, many domestic hydrological stations still use manual methods to monitor water levels. The water gauges used for manual water level measurement are divided into four types: vertical type, inclined type, short pile type and pendent type. Among them, the vertical water gauge is the most commonly used, and the other three are selected according to the terrain and needs.

Vertical water gauge:

The vertical water gauge is composed of a water gauge pile and a water gauge plate. Generally, a group of water gauge piles is set along the water level observation section, and each water gauge of the same group is set on the same section line. When in use, the water gauge plate is fixed on the water gauge pile to form an upright water gauge. The water gauge piles can be made of wood piles, steel pipes, reinforced concrete and other materials. The water gauge piles must be firm and driven into the river bottom to avoid sinking. The range of water gauge piles should be higher than the highest water level of the measuring station and 0.5 meters lower than the lowest water level of the measuring station. The water gauge board is usually made of enamel board, wood board or synthetic material with a length of 1 meter and a width of 8 to 10 cm. The scale of the water gauge must be clear, the numbers should be clear, and the lower edge of the numbers should be placed close to the corresponding scale. The scale of the water gauge is generally 1 cm, and the error is not greater than 0.5 mm. The water levels between two adjacent water gauges must overlap to a certain extent, and the overlapping range is generally required to be 0.1 to 0.2 meters. When the wind and waves are strong, the overlapping part should be increased to ensure continuous reading of the water level. After the water gauge plate is installed, it is necessary to measure the zero point elevation of each water gauge with the leveling method of level four or above. After reading the water level value on the water gauge plate, add the zero elevation of the water gauge to be the water level value to be observed.

Inclined water gauge:

This water gauge can be used when there is a regular and flat slope on the bank in the test section. At this time, the water scale scale can be directly painted on a flat slope (on the slope of a rock or a hydraulic structure). Let ΔZ represent the minimum length of the vertical water gauge, and represent the minimum length of the slope water gauge with a slope coefficient of m. Compared with the vertical water gauge, the inclined water gauge is durable, not easy to be washed out, and the zero point elevation of the water gauge is not easy The disadvantage is that the requirements are relatively strict. On sandy rivers, the scale of the water scale is easily covered by silt.

Low pile water gauge:

When it is seriously affected by shipping, drift ice, and floating transportation, it is not suitable to set up vertical water gauges and inclined water gauge stations, and low-pile water gauges can be used instead. The short pile type water gauge is composed of a short pile and a measuring ruler. The depth of the short pile is the same as that of the vertical water gauge. The top of the pile is generally 5-20cm higher than the river bed, and a metal garden nail with a diameter of 2-3cm is added to the top of the pile to place the measuring ruler. The height difference between two adjacent pile tops should be between 0.4-0.8m, and the flat bank slope should be between 0.2-0.4m. The measuring ruler is generally made of hard wood. In order to reduce backwater, the cross-section of the measuring ruler can be made into a rhombus. When observing the water level, put the measuring ruler vertically on the top of the pile, read the reading of the measuring ruler, and add the elevation of the pile top to get the water level.

Hanging hammer water gauge:

The pendent hammer water gauge is usually set on a solid steep bank, bridge or hydraulic structure. It is also used extensively in the measurement of groundwater levels and seepage levels in dams. A water gauge consisting of a measuring rope or chain with a weight attached to it. It is used to calculate the water level by measuring the vertical height difference from the water surface from a fixed point of known elevation above the water surface. The weight of the pendent hammer should be able to straighten the suspension cable, and the flexibility of the suspension cable should be very small. During use, the consistency between the effective length of the index and the counter or dial should be checked regularly, and the error should not exceed ±1cm.

The deficiencies of the above four methods of vertical, inclined, short pile and pendent hammer are: (1) the required data cannot be monitored in real time; (2) the rainfall of each monitoring point cannot be monitored at the same time; ( 3) The monitoring terrain is complicated, and there is a problem of personal safety of the measuring person.

In order to overcome the shortcomings of the above four methods, pressure-type and float-type contact water level gauges have appeared on the market, but the traditional pressure-type and float-type contact water level gauges have the following disadvantages: 1. The traditional water level gauge is only A single sensor cannot store and wirelessly transmit data; 2. Observation wells need to be built, and the deployment is inflexible. During the measurement process, the water surface is easy to interfere and destroy the flow field. It is only suitable for the measurement of narrow, variable and harmful flow fields. , The measuring device is affected by the impact of high-speed water flow and the winding and blocking of floating objects; 3. The mechanical float type water level gauge is prone to failure due to wear and corrosion of parts, which reduces the trouble-free working time.

At present, most of the existing ultrasonic liquid level gauges on the market use the temperature compensation method to correct the ultrasonic propagation speed to improve the measurement accuracy of the instrument. This method needs to add a temperature measurement unit to the system to obtain the actual sound velocity by measuring the ambient temperature; thus, the temperature measurement error is also introduced, which limits the further improvement of the system accuracy.

Utility model content

In order to overcome the deficiencies of the prior art, the utility model provides a wireless ultrasonic water level gauge, the water level gauge adopts the air medium measurement method, which integrates data collection, storage and transmission, and the wireless transmission adopts Zigbee technology, which not only has high measurement accuracy, but also Low power consumption, reliable data transmission, and reduced infrastructure investment.

The technical scheme that the utility model solves its technical problem adopts is:

A wireless ultrasonic water level gauge, comprising a column 1 arranged on the side of the water surface, the column 1 protrudes forward and is provided with an instrument box 2, the bottom of the instrument box 2 is provided with an ultrasonic sensor 5 and a temperature sensor 4, and the top of the instrument box 2 is provided with a radio frequency antenna 3. A reference baffle is fixed between the probe of the ultrasonic sensor 5 and the water surface. The instrument box 2 is provided with a CC2430 chip. The input end of the CC2430 chip is connected to the ultrasonic sensor 5 and the temperature sensor 4, and the output end is connected to the radio frequency antenna 3. The CC2430 chip uses Zigbee technology to connect with the host computer through the radio frequency antenna.

Furthermore, the CC2430 chip is connected to a power module, the power module is a solar cell device or a storage battery, and the solar cell device adopts a combined structure of a solar cell panel and a rechargeable battery.

Furthermore, the CC2430 chip can also be connected with the RS232 interface, and the RS232 interface is connected with the host computer.

Compared with the traditional water level gauge, the wireless ultrasonic water level gauge of the utility model has the following characteristics:

1. Wireless transmission and flexible networking. The distance between each measuring point and the host computer in the river engineering model test site can reach hundreds of meters, but the distance between nodes is mostly between a few meters to tens of meters. The communication protocol of ZigBee technology supports data in the form of relay Coordinate and complete communication between multiple measurement nodes without additional high-power radio frequency power amplifiers. The wireless connection simplifies the originally complicated connection between the equipment, facilitates the maintenance of the experimental device, and requires less infrastructure investment.

2. Low speed, low power consumption. The sampling frequency of the water level value in the river engineering model test is low, usually several times per second or even minutes, the data communication volume between nodes is not large, and the transmission rate of 250kb/s is sufficient to meet the demand; ZigBee technology adopts a variety of power-saving work Mode, the design can make the sensor nodes in the non-acquisition and processing state in the sleep state most of the time, so as to effectively control the power consumption and prolong the service life of the battery.

3. Low cost and low complexity. This system uses a cheap SoC hardware platform, which effectively reduces the product cost and development difficulty compared with the MCU+RF transceiver solution; the patent-free protocol stack and 214GHz open frequency band realize zero use cost.

4. Data transmission is reliable. The communication protocol of ZigBee technology sets communication mechanisms such as direct sequence spread spectrum and CSMA/CA in the PHY layer and MAC layer, which effectively guarantees the reliability of data transmission, and can transmit data correctly even in a laboratory environment with a lot of interference .

5. Large network capacity. One ZigBee technology network can accommodate up to 254 sensor nodes (slave devices) and one sink node (master device), and more than 200 ZigBee technology networks can exist in one area at the same time, which is enough to meet the layout requirements of large-scale models.

Description of drawings:

Fig. 1 is the structural representation of the utility model;

Fig. 2 is the system connection schematic diagram of the present utility model;

Fig. 3 is the schematic diagram of the transmission signal driving circuit of the present invention;

Fig. 4 is the schematic diagram of the receiving signal preprocessing circuit of the present utility model;

FIG. 5 is a schematic diagram of a two-stage amplifier circuit composed of an operational amplifier of the present invention.

Detailed ways:

In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution of the embodiment of the utility model will be clearly and completely described below in conjunction with the accompanying drawings of the embodiment of the utility model. Apparently, the described embodiments are some of the embodiments of the present invention, but not all of them. Based on the described embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

As shown in Figures 1-5, a wireless ultrasonic water level gauge of the present utility model includes a column 1 arranged on the side of the water surface. The column 1 protrudes forward and is provided with an instrument box 2. Sensor 4, radio frequency antenna 3 is arranged on the top of instrument box 2, and processor MCU (not shown in the figure) is arranged inside instrument box 2, preferably, processor MCU adopts CC2430 chip in a kind of wireless ultrasonic water level gauge of the present utility model .

As shown in Figure 2, the input end of the CC2430 chip is connected to the ultrasonic sensor 5 and the temperature sensor 4, and the output end is connected to the radio frequency antenna 3. Further, the CC2430 chip is connected to a power module, preferably, the power module is a solar cell device or a storage battery. Furthermore, the solar cell device can adopt a combined structure of a solar cell panel and a rechargeable battery, and the rechargeable battery is charged through the solar cell panel, which saves energy and improves the convenience of power supply. In addition, the CC2430 chip can also be connected with the RS232 interface, and the RS232 interface is wirelessly connected with the upper computer. In the wireless ultrasonic water level gauge of the present utility model, the processor MCU (CC2430 chip) can also adopt Zigbee technology to connect with the upper computer through the radio frequency antenna.

As shown in Figures 1-5, in a kind of wireless ultrasonic water level gauge of the present utility model, adopt gas-medium measurement mode, preferably, a reference baffle plate (not shown in figure) with good reflection performance is fixed on the ultrasonic sensor 5 At a certain distance between the probe and the water surface, accurate sound velocity correction can be achieved by measuring the echo time of the baffle; the processor MCU is preferably equipped with a single-chip dual timer, which reflects the echo and liquid back to the baffle. Waves are precisely timed. The water level gauge of the present utility model is a non-contact water level measuring device adopting the pulse ranging method. After being reflected back from the water surface, the instrument measures the time t from the time when the transmitted pulse is taken as the starting point to the time when the echo pulse is received. Calculate the distance s according to the sound velocity v at the temperature of the measuring point at that time, and then subtract the measured water surface from the sensor installation height h The distance is the water level L, that is, L=h-s=h-v(t/2).

CC2430 system-on-chip (SoC) is a highly integrated ZigBee technology solution, which integrates the industry-leading 214GHz RF transceiver CC2420 and industry-standard enhanced 8051MCU, and has 8kB SRAM and 128kB large-capacity flash memory, only High-speed, cheap sensor network nodes can be constructed with a small number of low-cost external components. Therefore, the hardware design of the node is based on the CC2430 chip, and the gas-mediated ultrasonic transducer is used together with the temperature sensor to realize the collection of water level information. The connection relationship between the point and the aggregation node inside and outside, the left side is the sensor node, and the right side is the aggregation The node communicates with the host computer through the serial port RS232.

It should be understood that although the present invention has been specifically shown and described with reference to its exemplary embodiments, those skilled in the art should understand that without departing from the spirit and scope of the present invention defined by the claims Various changes in form and details can be made therein, and any combination of various embodiments can be made under certain conditions.

Claims (5)

1. a wireless ultrasonic water-level gauge, it is characterized in that: comprise and be arranged on water surface column (1) on one side, column (1) stretches out forward and is provided with instrument box (2), instrument box (2) bottom is provided with ultrasonic sensor (5) and temperature sensor (4), instrument box (2) top is provided with radio-frequency antenna (3), between the probe that one reference baffle plate is fixed on ultrasonic sensor (5) and the water surface, instrument box (2) inside is provided with CC2430 chip, the input end of CC2430 chip is connected with ultrasonic sensor (5) and temperature sensor (4), output terminal is connected with radio-frequency antenna (3), CC2430 chip adopts ZigBee technology to be connected with host computer by radio-frequency antenna.

2. a kind of wireless ultrasonic water-level gauge according to claim 1, is characterized in that: CC2430 chip is connected with power module.

3. a kind of wireless ultrasonic water-level gauge according to claim 2, is characterized in that: power module is solar battery apparatus or accumulator.

4. a kind of wireless ultrasonic water-level gauge according to claim 3, is characterized in that: solar battery apparatus adopts the unitized construction of solar panel and rechargeable battery.

5. a kind of wireless ultrasonic water-level gauge according to claim 1, is characterized in that: CC2430 chip can also be connected with RS232 interface, and RS232 interface is connected with host computer.