Portable externally-attached ultrasonic liquid level indication measuring system and measuring method thereof

Abstract

According to the portable externally-attached ultrasonic liquid level indication measuring system and the measuring method thereof, an ultrasonic transmitting probe, an ultrasonic receiving probe and a temperature sensor are connected to the front end of a probe handle, a measuring key is fixed to the probe handle, and a handheld meter is connected with the ultrasonic transmitting probe, the ultrasonic receiving probe and the temperature sensor through cables. The ultrasonic transmitting probe and the ultrasonic receiving probe are simultaneously clung to the outer wall of the liquid storage container through the probe handles, ultrasonic waves transmitted by the ultrasonic probe pass through the outer wall of the liquid storage container, signals can be changed, the handheld meter carries out operation processing on the signals through a built-in artificial intelligence algorithm, and then the liquid-containing position and the liquid-free position of the liquid storage container can be calculated. Meanwhile, the temperature sensor detects the temperature of the liquid storage container, the weight of the liquid can be obtained through auxiliary calculation after parameters are input, one-key measurement is achieved, and the liquid level measuring device has the advantages of being low in power consumption, easy to carry and high in measuring precision.

Description

Technical Field

[0001] This invention relates to the field of liquid level measurement technology at a certain location in a sealed storage tank, specifically to a portable external ultrasonic liquid level indicator measurement system and its measurement method. Background Technology

[0002] In liquid level control engineering in industries such as pharmaceuticals, petroleum, chemicals, power, and food, it is essential to monitor the liquid level in storage tanks. When the liquid level in the storage tank reaches the upper and lower limits, the liquid level alarm device needs to issue a warning.

[0003] Currently available ultrasonic level measuring devices are broadly classified into two types: external and insertion. External devices require two ultrasonic probes: an ultrasonic transmitting probe connected to the transmitter's output terminal and an ultrasonic receiving probe connected to the transmitter's input terminal. Furthermore, the two probes must be installed on the same horizontal line with minimal distance between them. Insertion devices require production shutdown for drilling and welding, which is unsuitable for applications with explosion-proof requirements or for alarming excessive levels of toxic or corrosive liquids. Moreover, both types of devices generally suffer from the drawback of using separate ultrasonic probes and transmitters and lacking a display, increasing system size and the likelihood of damage from dragging.

[0004] Existing ultrasonic liquid level detection equipment, both domestically and internationally, requires too much human intervention in its operation. Operators must manually adjust the transmission power according to the on-site working conditions, visually observe the pointer voltmeter, and simultaneously rotate the gain adjustment knob. This necessitates considerable operational experience for correct measurement, and the accuracy of the measurement results is only 2%-5%FS. This type of measurement equipment and method has many shortcomings in practical use. For example, it demands a high level of operator experience, and the measurement results cannot be guaranteed. Furthermore, the equipment is constantly in operation after startup, resulting in high power consumption and requiring a large-capacity rechargeable lithium battery, making it inconvenient to carry. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention aims to provide a portable external ultrasonic liquid level indicator measurement system and its measurement method, which can realize low power consumption mode measurement, automatic intelligent control of power on and off, automatic calibration of liquid level measurement and one-click measurement of outer wall temperature, keep the liquid level measurement accuracy in the range of 0.1%-0.5%FS, and can perform self-learning and correction, thereby improving the stability of liquid level detection results.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A portable external ultrasonic liquid level indicator and measurement system includes a handheld meter, a cable, an ultrasonic transmitting probe, an ultrasonic receiving probe, a measurement button, and a temperature sensor. The ultrasonic transmitting probe, ultrasonic receiving probe, and temperature sensor are connected to the front end of the probe handle, the measurement button is fixed to the probe handle, and the handheld meter is connected to the ultrasonic transmitting probe, ultrasonic receiving probe, and temperature sensor via a cable.

[0007] The handheld watch consists of an LCD touchscreen display, an MCU control module, a transmitting circuit, a receiving circuit, a data storage module, a temperature acquisition module, a buzzer module, an LCD touchscreen RGB circuit, a power management module, a push-button switch, and a lithium battery pack. The MCU control module bidirectionally connects to the data storage module, the temperature acquisition module, and the LCD touchscreen RGB circuit, and unidirectionally connects to the LCD touchscreen display, the transmitting circuit, the receiving circuit, the measurement buttons, the temperature sensor, the buzzer module, and the power management module. The transmitting circuit connects to the ultrasonic transmitting probe; the receiving circuit connects to the ultrasonic receiving probe; and the power management module, push-button switch, and lithium battery pack are also included.

[0008] The handheld meter uses a TLI-driven LCD touch screen and is equipped with an image processing accelerator (IPA) to enable parameter setting and measurement result reading.

[0009] The MCU control module, power management module, and push-button switch efficiently control the power supply process of the lithium battery pack.

[0010] The liquid level measurement process can be completed with a single button press via the measurement switch on the probe handle. The result is displayed on the LCD touch screen of the handheld watch, and the liquid level status is indicated by a buzzer module.

[0011] The handheld meter has a built-in temperature acquisition module that can collect the temperature of the liquid storage container wall in real time and transmit the results to the MCU control module. The temperature value of the liquid storage container is then displayed in real time on the LCD touch screen.

[0012] A portable external ultrasonic liquid level indicator measurement method includes the following steps: Step 1, System Initialization: Disable global interrupts and watchdog timer to prevent system initialization failure due to interrupts, initialize stack, set internal crystal oscillator to be used, initialize I / O ports, RAM units, AD converters, LEDs, and transmit ports; after all initialization is complete, delay for 4 seconds and clear flags FLAG1.0 and FLAG2 to 0. Step 2: Emitter an ultrasonic signal of a certain frequency; Step 3: Enable AD interrupt, start sampling, and wait for sampling to finish; Step 4: Store the fundamental frequency? If not, store the fundamental frequency and set the fundamental frequency flag FLAG1.1. If it is stored, skip this step. Step 5: Find the first surrounding peak. First, find the full-amplitude value point. If found, jump to the previous point. If not, find the maximum amplitude value point and compare it with the threshold value. If it is larger, it is considered a valid point and jumps to the previous two points; if it is smaller, it is considered an invalid point and directly displays that no measurement was taken. Step 6: Calculate the mean of peak 1 based on the first peak point found; Step 7: Calculate the mean of valley 1. The number of valley points is selected based on experience, starting from the 7th point after peak sampling. Step 8: Return to the starting point of the current peak, and select the first point of the next peak based on the echo time. Step 9: Repeat steps 6-8 to complete the calculation of the average values ​​of the first 5 peaks and troughs; Step 10: Calculate the peak-to-valley ratio for each peak based on the peak-to-valley average, and sum the averages of the five peaks. Determine the three states of liquid presence, liquid absence, and no measurement based on the large and small thresholds. If the number of measurements exceeding the large threshold exceeds 3, it is directly judged as liquid absence. If it is less than 3, determine the number of measurements exceeding the small threshold. If the number of measurements exceeding the small threshold is less than 3, it is judged as no measurement; otherwise, it is judged as liquid presence.

[0013] The beneficial effects of this invention are as follows: The advantages of the portable external ultrasonic liquid level indicator and measurement system and method of the present invention are that, through the artificial intelligence algorithm built into the portable handheld meter, it can realize one-click measurement of the liquid level position and outer wall temperature in the container and real-time display on the LCD touch screen, and can calculate the weight of the liquid in the container by input parameters. It has the characteristics of low power consumption, easy portability and high measurement accuracy. Attached Figure Description

[0014] Figure 1 This is an overall structural diagram provided for an embodiment of the present invention; Figure 2 A diagram of a handheld watch module provided in an embodiment of the present invention; Figure 3 A system calibration flowchart provided for embodiments of the present invention; Figure 4 A system low-power flowchart provided for embodiments of the present invention; Figure 5 A system measurement flowchart provided for an embodiment of the present invention.

[0015] Among them, 1 is a handheld watch, 2 is a cable, 3 is an ultrasonic transmitting probe, 4 is an ultrasonic receiving probe, 5 is a measurement button, 6 is a temperature sensor, 7 is a probe handle, 8 is a liquid storage container, 10 is an MCU control module for the handheld watch, 11 is an LCD touch screen, 12 is a transmitting circuit, 13 is a receiving circuit, 14 is a data storage module, 15 is a temperature acquisition module, 16 is a buzzer module, 17 is an LCD touch screen RGB circuit, 18 is a power management module, 19 is a push-button switch, and 20 is a lithium battery pack. Detailed Implementation

[0016] The invention will be further described below with reference to the accompanying drawings and principles.

[0017] like Figures 1 to 3 As shown, a portable external ultrasonic liquid level indicator and measurement system includes a handheld meter 1, a cable 2, an ultrasonic transmitting probe 3, an ultrasonic receiving probe 4, a measurement button 5, and a temperature sensor 6. The ultrasonic transmitting probe 3, the ultrasonic receiving probe 4, and the temperature sensor 6 are connected to the front end of a probe handle 7. The measurement button 5 is fixed to the probe handle 7. The handheld meter 1 is connected to the ultrasonic transmitting probe 3, the ultrasonic receiving probe 4, and the temperature sensor 6 via the cable 2. The ultrasonic transmitting probe 3 and the ultrasonic receiving probe 4 are simultaneously attached to the outer wall of a liquid storage container 8 via the probe handle 7.

[0018] The handheld watch 1 consists of an LCD touch screen 11, an MCU control module 10, a transmitting circuit 12, a receiving circuit 13, a data storage module 14, a temperature acquisition module 15, a buzzer module 16, an LCD touch screen RGB circuit 17, a power management module 18, a push-button switch 19, and a lithium battery pack 20. The MCU control module 10 is bidirectionally connected to the data storage module 14, the temperature acquisition module 15, and the LCD touch screen RGB circuit 17, and unidirectionally connected to the LCD touch screen 11, the transmitting circuit 12, the receiving circuit 13, the measurement button 5, the temperature sensor 6, the buzzer module 16, and the power management module 18. The transmitting circuit 12 is connected to the ultrasonic transmitting probe 3; the receiving circuit 13 is connected to the ultrasonic receiving probe 4; and the power management module 18, the push-button switch 19, and the lithium battery pack 20 are also connected.

[0019] The handheld watch 1 uses an LCD touch screen 11 driven by TLI and is equipped with an IPA image processing accelerator.

[0020] The on / off switching of the MCU control module 10, power management module 16, and push-button switch 17 efficiently controls the power supply process of the lithium battery pack 18.

[0021] The liquid level measurement process can be completed with one-button measurement via the measurement switch 5 on the probe handle 7, and the result is displayed on the LCD touch screen 10 of the handheld meter 1, and the liquid level status is indicated by the buzzer module 14.

[0022] The temperature acquisition module 15 built into the handheld meter 1 can acquire the temperature of the tank wall of the liquid storage container 8 in real time and transmit the result to the MCU control module 10. The temperature value of the liquid storage container 8 is displayed in real time through the LCD touch screen 11.

[0023] A portable external ultrasonic liquid level indicator measurement method includes the following steps: Step 1, System Initialization: Disable global interrupts and watchdog timer to prevent system initialization failure due to interrupts, initialize stack, set internal crystal oscillator to be used, initialize I / O ports, RAM units, AD converters, LEDs, and transmit ports; after all initialization is complete, delay for 4 seconds and clear flags FLAG1.0 and FLAG2 to 0. Step 2: Emitter an ultrasonic signal of a certain frequency; Step 3: Enable AD interrupt, start sampling, and wait for sampling to finish; Step 4: Store the fundamental frequency? If not, store the fundamental frequency and set the fundamental frequency flag FLAG1.1. If it is stored, skip this step. Step 5: Find the first surrounding peak. First, find the full-amplitude value point. If found, jump to the previous point. If not, find the maximum amplitude value point and compare it with the threshold value. If it is larger, it is considered a valid point and jumps to the previous two points; if it is smaller, it is considered an invalid point and directly displays that no measurement was taken. Step 6: Calculate the mean of peak 1 based on the first peak point found; Step 7: Calculate the mean of valley 1. The number of valley points is selected based on experience, starting from the 7th point after peak sampling. Step 8: Return to the starting point of the current peak, and select the first point of the next peak based on the echo time. Step 9: Repeat steps 6-8 to complete the calculation of the average values ​​of the first 5 peaks and troughs; Step 10: Calculate the peak-to-valley ratio for each peak based on the peak-to-valley average, and sum the averages of the five peaks. Determine the three states of liquid presence, liquid absence, and no measurement based on the large and small thresholds. If the number of measurements exceeding the large threshold exceeds 3, it is directly judged as liquid absence. If it is less than 3, determine the number of measurements exceeding the small threshold. If the number of measurements exceeding the small threshold is less than 3, it is judged as no measurement; otherwise, it is judged as liquid presence.

[0024] All circuit modules of the handheld watch utilize low-power components and are controlled by a power management module. A push-button switch is placed between the lithium battery pack and the power management module. By switching the switch on and off, the power supply to the lithium battery pack is controlled, including the LCD touchscreen RGB circuitry and the receiving circuitry. This ensures the lithium battery pack is connected when the handheld watch is working and disconnected when not in use, efficiently controlling the battery power supply, improving battery efficiency, enabling low-power operation, and effectively extending the handheld watch's operating time. The following solutions are also included: The MCU control module is frequency-reduced to reduce system power consumption. When the MCU control module is in standby mode, the microcontroller operates in sleep mode. The MCU control module operates at 3V to improve the efficiency of the lithium battery pack. For unused I / O ports in the MCU control module, set them to input mode to further reduce the overall power consumption of the handheld meter.

[0025] For high-precision measurement of the liquid level inside a storage container, the present invention employs the following measurement method: The ultrasonic transmitting and receiving probes are tightly attached to the outer wall of the liquid storage container by pressing the probe handle. After pressing the measurement button on the probe handle, the MCU control module of the handheld device controls the transmitting circuit to couple and generate a set of high-voltage pulse signals of a certain frequency, which are emitted through the ultrasonic transmitting probe. The high-voltage pulses generate a circling wave that propagates vertically along the outer wall of the liquid storage container. At the solid-gas interface, due to the weak transmission energy, the sound wave attenuates less and can propagate along the container wall for a longer time, generating first and higher-order circling waves. At the solid-liquid interface, due to the relatively large transmission energy and the rapid attenuation of surface wave energy after multiple transmissions, the energy of higher-order circling waves is weaker, or even non-existent. Based on the order and amplitude of the circling waves, the solid-gas interface and the solid-liquid interface can be distinguished, and thus the liquid level position inside the liquid storage container can be determined.

[0026] Meanwhile, the handheld meter's built-in temperature acquisition module can collect the tank wall temperature of the liquid storage container in real time and transmit the results to the MCU control module, displaying the temperature value of the liquid storage container in real time through the LCD touch screen.

[0027] The MCU control module processes the ultrasonic signal to calculate the position of the liquid storage container, thus determining the liquid level. At the same time, the temperature sensor sends the temperature detection result of the liquid storage container to the MCU control module. The MCU control module can calculate the weight of the liquid in the liquid storage container by using the parameters of the liquid storage container and the liquid medium set by the user on the LCD touch screen of the handheld device, and display it in real time on the LCD touch screen.

[0028] Low-power measurement examples using handheld meters: like Figure 4 As shown, all circuit modules of the handheld meter 1 use low-power components and are powered by the power management module 18. A push-button switch 19 is placed between the lithium battery pack 20 and the power management module 18. By turning the push-button switch 19 on and off, the LCD touch screen RGB circuit 17 and the receiving circuit 13 are controlled, that is, the lithium battery pack 20 is turned on when the handheld meter 1 is working and turned off when it is not working. For some pull-up resistors and voltage divider resistors, resistors with large resistance values ​​are selected. The MCU control module 10 is frequency-reduced to reduce system power consumption. When the MCU control module 10 is in standby mode, the microcontroller works in sleep mode. The operating voltage of the MCU control module 10 is 3V to improve the utilization efficiency of the lithium battery pack 20. For the unused IO ports in the MCU control module 10, they are set to input mode to further reduce the overall power consumption of the handheld meter 1.

[0029] The system controls the LCD touch screen 11 through the power management module. That is, after the system has been working for a period of time, the MCU control module 10 determines that the handheld meter 1 has entered standby mode when there is no operation. The system sleeps for a period of time, and the brightness of the LCD touch screen 11 is at its lowest. At this time, if the LCD touch screen 11 is touched or the measurement button 5 is pressed, the system enters working mode. When the standby time is longer than a certain period of time, the handheld meter 1 system automatically shuts down.

[0030] The liquid level measurement process is performed by one-button measurement switch 5 on probe handle 7, the result is displayed on LCD touch screen 11 of handheld meter 1, and liquid level status is indicated by buzzer module 16.

[0031] Example of automatic calibration and measurement process for handheld watches: like Figure 3 As shown, after the handheld meter 1 receives the calibration command, in the automatic calibration process, the gain is automatically adjusted by the circuit so that the amplitude of the echo signal reaches a certain peak. When the condition is met, the local peak search algorithm is called to automatically find the peak position. When the set number of peaks are found, the automatic calibration process is completed. Finally, the current gain setting and the positions of the first and second peaks are recorded. At this time, the data is saved to the data storage module 14.

[0032] like Figure 5As shown, the handheld watch 1 first starts transmitting and receiving ultrasonic signals, then reads and stores parameters through the data storage module 14, draws left and right truncated line segments on the acquired waveform curve, and determines whether the selected left and right truncated line segments are out of range. If they are out of range, it prompts "peak out of bounds" and redraws the left and right truncated line segments. Then, it reads the peak and valley values ​​of the first 5 circumferential waves in the waveform curve, calculates the peak-to-valley ratio of each circumferential wave, and calculates the mean and standard deviation of the peak value, valley value, and peak-to-valley ratio of each circumferential wave.

[0033] Then determine whether the average peak-to-valley ratio is greater than or equal to 2. If so, it means that the measurement location is in a liquid-free state. Otherwise, continue to determine whether the average peak-to-valley ratio is greater than or equal to 1.9 and the standard deviation of the peak-to-valley ratio is less than or equal to 0.2. If this condition is met, it means that the measurement location is in a liquid-free state. Otherwise, continue to determine whether the average peak-to-valley ratio is less than or equal to 1.1. If so, it means that the probe is in an unconnected state. If none of the above conditions are met, it means that the measurement location is in a liquid-free state.

[0034] Next, the peak-to-valley ratio of the seven surround waves is judged sequentially. Variable C is incremented by 1 each time the peak-to-valley ratio is greater than or equal to 2.5, and variable D is incremented by 1 each time the peak-to-valley ratio is less than or equal to 1.4. Then, it is determined that when C is greater than or equal to 4, the measurement position is considered to be in a liquid-free state, and when D is greater than or equal to 3, the probe is considered to be disconnected. If none of the above conditions are met, it indicates that the measurement position is in a liquid-containing state. At this time, the LCD touch screen 11 displays the liquid-containing state, and at the same time, the buzzer module 16 emits a prompt sound to indicate that the liquid-containing state is present.

[0035] Meanwhile, the temperature acquisition module 15 built into the handheld meter 1 can collect the temperature of the tank wall of the liquid storage container 8 in real time and transmit the result to the MCU control module 10, and display the temperature value of the liquid storage container 8 in real time through the LCD touch screen 11.

[0036] The MCU control module 10 processes the ultrasonic signal to calculate the position of the liquid storage container 8 (whether there is liquid or not), thereby determining the height of the liquid level. At the same time, the temperature sensor 6 transmits the temperature detection result of the liquid storage container 8 to the MCU control module 10. The MCU control module 10 can calculate the weight of the liquid in the liquid storage container 8 and the liquid medium through the parameters of the liquid storage container 8 and the liquid medium set by the user on the LCD touch screen 11 of the handheld meter 1, and display it in real time on the LCD touch screen 11.

Claims

1. A portable external ultrasonic liquid level indicator and measurement system, comprising a handheld meter (1), a cable (2), an ultrasonic transmitting probe (3), an ultrasonic receiving probe (4), a measurement button (5), and a temperature sensor (6), characterized in that, The ultrasonic transmitting probe (3), ultrasonic receiving probe (4) and temperature sensor (6) are connected to the front end of the probe handle (7). The measurement button (5) is fixed on the probe handle (7). The handheld meter (1) is connected to the ultrasonic transmitting probe (3), ultrasonic receiving probe (4) and temperature sensor (6) via a cable (2).

2. The portable external ultrasonic liquid level indicator and measurement system according to claim 1, characterized in that, The handheld meter (1) consists of an LCD touch screen (11), an MCU control module (10), a transmitting circuit (12), a receiving circuit (13), a data storage module (14), a temperature acquisition module (15), a buzzer module (16), an LCD touch screen RGB circuit (17), a power management module (18), a push button switch (19), and a lithium battery pack (20). The MCU control module (10) is bidirectionally connected to the data storage module (14), the temperature acquisition module (15), and the LCD touch screen RGB circuit (17), and unidirectionally connected to the LCD touch screen (11), the transmitting circuit (12), the receiving circuit (13), the measurement button (5), the temperature sensor (6), the buzzer module (16), and the power management module (18). The transmitting circuit (12) is connected to the ultrasonic transmitting probe (3). The receiving circuit (13) is connected to the ultrasonic receiving probe (4). The power management module (18), the push button switch (19), and the lithium battery pack (20) are also connected.

3. The portable external ultrasonic liquid level indicator and measurement system according to claim 2, characterized in that, The handheld watch (1) uses an LCD touch screen (11) driven by TLI and is equipped with an image processing accelerator (IPA).

4. A portable external ultrasonic liquid level indicator and measurement system according to claim 2, characterized in that, The on / off switching of the MCU control module (10), power management module (16), and push button switch (17) efficiently controls the power supply process of the lithium battery pack (18).

5. A portable external ultrasonic liquid level indicator and measurement system according to claim 2, characterized in that, The liquid level measurement process can be completed by one-click measurement via the measurement switch (5) on the probe handle (7), and the result is displayed on the LCD touch screen (10) of the handheld meter (1), and the liquid level status is indicated by the buzzer module (14).

6. A portable external ultrasonic liquid level indicator and measurement system according to claim 2, characterized in that, The temperature acquisition module (15) built into the handheld meter (1) can collect the temperature of the tank wall of the liquid storage container (8) in real time and transmit the result to the MCU control module (10), and display the temperature value of the liquid storage container (8) in real time through the LCD touch screen (11).

7. A portable external ultrasonic liquid level indicator measurement method, characterized in that, Includes the following steps: Step 1, System Initialization: Disable global interrupts and watchdog timer to prevent system initialization failure due to interrupts, initialize stack, set internal crystal oscillator to be used, initialize I / O ports, RAM units, AD converters, LEDs, and transmit ports; after all initialization is complete, delay for 4 seconds and clear flags FLAG1.0 and FLAG2 to 0. Step 2: Emitter an ultrasonic signal of a certain frequency; Step 3: Enable AD interrupt, start sampling, and wait for sampling to finish; Step 4: Store the fundamental frequency? If not, store the fundamental frequency and set the fundamental frequency flag FLAG1.

1. If it is stored, skip this step. Step 5: Find the first surrounding peak. First, find the full-amplitude value point. If found, jump to the previous point. If not, find the maximum amplitude value point and compare it with the threshold value. If it is larger, it is considered a valid point and jumps to the previous two points; if it is smaller, it is considered an invalid point and directly displays that no measurement was taken. Step 6: Calculate the mean of peak 1 based on the first peak point found; Step 7: Calculate the mean of valley 1. The number of valley points is selected based on experience, starting from the 7th point after peak sampling. Step 8: Return to the starting point of the current peak, and select the first point of the next peak based on the echo time. Step 9: Repeat steps 6-8 to complete the calculation of the average values ​​of the first 5 peaks and troughs; Step 10: Calculate the peak-to-valley ratio for each peak based on the peak-to-valley average, and sum the averages of the five peaks. Determine the three states of liquid presence, liquid absence, and no measurement based on the large and small thresholds. If the number of measurements exceeding the large threshold exceeds 3, it is directly judged as liquid absence. If it is less than 3, determine the number of measurements exceeding the small threshold. If the number of measurements exceeding the small threshold is less than 3, it is judged as no measurement; otherwise, it is judged as liquid presence.

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