Accurate water leakage detection positioning device and method

Abstract

The invention relates to an accurate water leakage detection positioning device and method. The device comprises an accurate detection circuit, a water leakage detection belt, a detection controller and a water leakage protection circuit. The accurate detection circuit detects the resistance of the water leakage detection belt by using an H-bridge circuit; the water leakage detection belts are composed of long strip-shaped resistors with uniform resistance values, the water leakage detection belts are arranged at screw seals of all joints of the mechanical arm, and all the water leakage detection belts are connected in series to form a loop; the detection controller is used for controlling the H bridge to send out voltage pulses for resistance measurement, sampling voltage and current, executing a water leakage measurement method, accurately calculating and positioning, and sending out a protection signal; the water leakage protection circuit is composed of power supply relay signal lines of all joints. After the detection controller detects water leakage, a protection signal is sent to the water leakage protection circuit of the corresponding joint, and the power supply is cut off in sections. According to the invention, timely and accurate water leakage detection and accurate positioning are realized at low cost, and the safety and protection of underwater mechanical arm equipment are ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of water leakage detection and protection, and relates to an accurate water leakage detection and positioning device and method. Background Art

[0002] The underwater manipulator is an electromechanical product with a large number of internal circuits. When operating underwater, it is necessary to prevent water leakage. At present, the position detection of water leakage detection is realized by using simple measuring resistors, which is relatively rough, and the detection accuracy and detection distance are limited. The detection accuracy is usually 2 to 5 meters, and the real-time detection time is also weak.

[0003] After investigating the existing technologies, the following related technologies exist:

[0004] Journal of Inner Mongolia University (Natural Science Edition) "Application of Generalized Correlation Time Delay Estimation Method in Water Leakage Detection and Positioning": The problem of time delay estimation of pipeline leakage noise signal is handled based on generalized correlation time delay estimation. The disadvantage is that it is not used in underwater robot scenarios and the leak location is not accurately located.

[0005] South China University of Technology: "Realization of Water Leakage Detection and Positioning System Based on Single-Chip Microcomputer and DSP": It uses the sampling of single-chip microcomputer and variable step length LMS algorithm to remove noise from the collected input signal, and designs the software design of water leakage detection. The disadvantage is that the positioning accuracy is not high.

[0006] Shandong University of Science and Technology: Design of a household water leakage detection system based on DSP: A household water leakage detection system was designed based on DSP and single-chip microcomputer. The hardware and software parts of the system were designed using the detection and positioning principles of acoustic signal power spectrum analysis and correlation analysis. The disadvantage is that it is easily interfered and the positioning accuracy of water leakage detection is not high.

[0007] Patent 201821481963.8 "A water floor heating pipeline leakage detection and positioning device": including a host computer, a GPRS module, a microprocessor, and a water heating pipeline; using sensors and communications to detect the leakage location and display it on the host computer. The disadvantage is that more sensors need to be deployed for accurate positioning, the cost is high, and the project implementation is difficult.

[0008] Patent 202322198030.5 "A Linear Leakage Detection and Positioning Circuit with Adjustable Sensitivity": Uses a single-chip microcomputer and multiple control circuits and sensitivity adjustment circuits to detect the location of the leak. The key point is that the sensitivity is adjustable, and the positioning accuracy is not very high. The disadvantage is that the positioning accuracy is not high enough.

[0009] Patent 2016211624869.X "LoRa-based valve leakage detection and positioning system": It consists of a LoRa communication system, a detection module, a mobile phone and a PC. The detection module is used to detect leakage, the LoRa communication system is used to locate, and the data is conveniently uploaded to the mobile phone and PC. The advantages are the timeliness of leakage detection and remote visualization. The disadvantages are that the use of the detection module and the LoRa communication system is costly, and the detection accuracy depends on the number of LoRa communication nodes. Summary of the invention

[0010] The technical problem solved by the present invention is to overcome the deficiencies of the prior art and provide an accurate water leakage detection and positioning device and method, so as to realize timely and accurate water leakage detection and precise positioning at low cost, and ensure the safety and protection of underwater manipulator equipment.

[0011] The technical solution of the present invention is: an accurate water leakage detection and positioning device, including an accurate detection circuit, a water leakage detection belt, a detection controller, and a water leakage protection circuit;

[0012] The precise detection circuit is used to detect the resistance of the water leakage detection belt, including a detection inductor, an H-bridge, a voltage acquisition circuit and a current acquisition circuit; the H-bridge DC input is connected to the power supply of the mechanical arm, and each bridge arm output is connected to the detection inductor and the water leakage detection belt in turn, the voltage acquisition circuit is used to collect the voltage between the two bridge arms, and the current acquisition circuit is used to collect the bridge arm current;

[0013] The water leakage detection belt is composed of long strip resistors with uniform resistance. A water leakage detection belt is arranged at each joint of the robot arm, and all the water leakage detection belts are connected in series to form a loop;

[0014] The detection controller is used to control the H-bridge to send voltage pulses to measure the resistance of the water leakage detection belt, sample voltage and current, confirm the distance by measuring the resistance, accurately calculate the location, and send out a protection signal;

[0015] The water leakage protection circuit is composed of the power relay signal lines of each joint. After the detection controller detects water leakage, it sends a protection signal to the water leakage protection circuit of the corresponding joint and cuts off the power supply in sections.

[0016] Furthermore, the H bridge is composed of four MOS tubes Q1 to Q4 with anti-parallel diodes, Q1 and Q2 form bridge arm 1, Q3 and Q4 form bridge arm 2, and the current collection circuit collects the current when the upper tube Q1 of bridge arm 1 is turned on and the lower tube Q4 of bridge arm 2 is turned on.

[0017] Furthermore, the detection inductance has a value between 0.1 mH and 1 mH.

[0018] Furthermore, the resistance of the water leakage detection belt is measured using a pulse voltage method as follows:

[0019] according to

[0020]

[0021] get

[0022] Where: L is the detection inductance value, U N is the rated voltage, d is the given duty cycle, t s is the sampling period, i(n) is the current sampling value, and i(n-1) is the previous current sampling value.

[0023] Furthermore, the resistance of the water leakage detection belt is measured by direct Ohm's method.

[0024] A precise water leakage detection and positioning method comprises the following steps:

[0025] S1, using the pulse voltage method, using the H-bridge to output step voltage, record the sampling period t s , when the current reaches 0.632 times the rated current, according to Calculate the total resistance R1 of the first water leakage detection belt, measure it multiple times, and calculate the fluctuation μ1 of R1; L is the detection inductance value, U N is the rated voltage, d is the given duty cycle, i(n) is the current sampling value, and i(n-1) is the previous current sampling value;

[0026] S2, turn on the upper tube Q1 of bridge arm 1, turn on the lower tube Q4 of bridge arm 2, collect current, gradually increase the opening time of bridge arm 1 and bridge arm 2, wait for the current to reach 1 / 2 of the rated current, keep the duty cycle unchanged, collect the current and voltage at this time, low-pass filter them respectively, record the filtered current i and voltage u, calculate the total resistance value R2=u / i of the second water leakage detection belt, repeat the measurement and take the average value, measure multiple times, and calculate the fluctuation amount μ2 of R2;

[0027] S3. Calculate the total resistance R of the leakage detection belt accurately by using the minimum error calculation method for R1 and R2:

[0028]

[0029] S4. After the set waiting interval, repeat S1 to S3. When it is detected that the total resistance R becomes smaller, the leakage position is obtained by looking up the relationship table between resistance and distance, and then converted into a joint number, and the power supply of the joint is cut off to protect the equipment.

[0030] The beneficial effects of the present invention compared with the prior art are:

[0031] (1) The present invention realizes the leakage distance detection of the parameter identification method, applies the mature parameter identification method to the leakage detection, and comprehensively improves the measurement quality and measurement efficiency.

[0032] (2) The present invention realizes water leakage detection at low cost by arranging detection belts.

[0033] (3) The present invention automatically detects the distance of water leakage and protects the main circuit, thereby reducing errors and mistakes caused by water leakage to the product.

[0034] (4) The parameter identification method of the present invention effectively improves the distance and response time of water leakage detection, which is faster and more accurate than the existing water leakage detection methods, with a detection time of <100ms and a detection accuracy of <100cm, which is better than the commonly used detection accuracy of 2 to 5 meters. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the water leakage detection structure of the present invention;

[0036] Figure 2 A schematic diagram of arranging a water leakage detection belt according to the present invention;

[0037] Figure 3 This is a schematic diagram of the precise detection circuit of the present invention;

[0038] Figure 4 This is a flow chart of the precise water leakage detection and positioning method of the present invention. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0040] like Figure 1 As shown, the present invention provides an accurate water leakage detection and positioning device, including an accurate detection circuit, a water leakage detection belt, a detection controller, and a water leakage protection circuit.

[0041] The precise detection circuit is used to detect the resistance of the water leakage detection belt, including a detection inductor, an H-bridge, a voltage acquisition circuit and a current acquisition circuit; the H-bridge DC input is connected to the power supply of the underwater robotic arm, and each bridge arm output is connected to the detection inductor and the water leakage detection belt in turn. The voltage acquisition circuit is used to collect the voltage between the two bridge arms, and the current acquisition circuit is used to collect the bridge arm current.

[0042] The water leakage detection belt is composed of a long strip resistor with uniform resistance. The water leakage detection belt is arranged at the screw seal of each joint of the underwater robotic arm, and all the water leakage detection belts are connected in series to form a loop.

[0043] The detection controller is used to control the H-bridge to send out voltage pulses to measure the resistance of the water leakage detection belt, and to sample the voltage and current, execute the water leakage measurement method, accurately calculate the location, and send out a protection signal.

[0044] The water leakage protection circuit is composed of the power relay signal circuits of each joint; after the detection controller detects water leakage, it sends a protection signal to the water leakage protection circuit of the corresponding joint, cuts off the power supply in sections, and protects the main circuit of the robot arm.

[0045] The method of accurate water leak detection is:

[0046] Connect a precise detection circuit to the electric control box to detect the resistance of the water leakage detection belt. If the resistance becomes smaller, it is determined that there is a water leakage. The size of the resistance is used to determine which joint it belongs to. The size of the resistance is measured to determine the location of the water leakage.

[0047] Example 1

[0048] In this embodiment, the precise water leakage detection and positioning device is as follows: Figure 1 As shown, the invention is composed of four parts: a water leakage detection belt, a precise detection circuit, a detection controller and a water leakage protection circuit.

[0049] Leak detection tape Figure 2 As shown, it is a long strip resistor that can be attached to the inner wall of the robot arm, with uniform resistance. A water leakage detection tape is arranged at the screw seal of each joint and attached to the seal of the joint. All the water leakage detection tapes are connected in series to form a loop.

[0050] (1) Place a leak detection tape on each screw seal. The leak detection tape is a long strip with resistance that can be attached to the inner wall of the equipment.

[0051] (2) All water leakage detection belts are connected in series. In this embodiment, each joint is provided with a 1KΩ resistor, and 7 joints are connected in series, with a total of 7KΩ resistors.

[0052] (3) Connect a precise detection circuit to the electrical control box to detect the resistance of the water leakage detection belt. If the resistance decreases, it is determined that there is a water leakage. According to the size of the resistance, determine which joint it belongs to. Measure the size of the resistance to determine the location of the water leakage.

[0053] Precise detection circuit such as Figure 3 As shown, it consists of a detection inductor, an H-bridge, a voltage acquisition circuit, and a current acquisition circuit. The H-bridge of the precise detection circuit consists of four MOS tubes Q1 to Q4 with anti-parallel diodes. Q1 and Q2 form bridge arm 1, and Q3 and Q4 form bridge arm 2. The H-bridge DC input is connected to the 48V power supply of the underwater manipulator arm. The output of each bridge arm is connected to the detection inductor and the water leakage detection belt in turn. The voltage acquisition circuit is used to collect the voltage between the two bridge arms, and the current acquisition circuit is used to collect the bridge arm current.

[0054] Use the pulse voltage method to detect resistance, according to the inductance formula: in:

[0055] Again Δi=i(n)-i(n-1), i(n) is the current sampling value, i(n-1) is the previous current sampling value, t s is the sampling period, which is 0.0001 seconds here. U=U N ·d,U N is the rated voltage, here is 24V, d is the given duty cycle, [0.1, 0.9], here we take 0.5. In summary, we can get the calculation of the resistance value: Where L is the inductance, which is a known quantity. According to the calculation process and related parameters, for example, if the voltage is 24V, the current sampling is more suitable at 1A according to the sampling accuracy, and the L value is more suitable between 0.1mH and 1mH.

[0056] The precise positioning of water leakage detection based on parameter identification method uses H-bridge to inject voltage into the water leakage detection belt, connects the detection inductor in series at the front of the water leakage detection belt, measures the resistance of the water leakage detection belt by pulse voltage method and direct ohm method, and then synthesizes it into precise resistance value. See steps 1 to 3 below for details.

[0057] In this embodiment, the detection controller is a low-cost 8-bit single-chip microcomputer, which controls the H-bridge to send voltage pulses to measure the resistance of the leakage detection belt, and samples the voltage and current, executes the leakage measurement method, accurately calculates the location, and sends a protection signal.

[0058] The water leakage protection circuit is composed of the power relay signal lines of each joint. After the detection controller detects water leakage, it sends a protection signal to the water leakage protection circuit of the corresponding joint, cuts off the power supply in sections, and protects the main circuit of the robotic arm.

[0059] The core purpose of accurate water leakage measurement is to locate the location of the water leakage and provide protection. The positioning principle is to confirm the distance by measuring the resistance; the protection is to protect in sections and cut off the power supply in sections.

[0060] The length of the water leakage detection tape can be calculated based on its resistance, and the location of the water leakage can be located. The direction and size of the water leakage can also be determined based on the change in resistance, that is, the change in position. Figure 4 As shown, an accurate water leakage detection and positioning method is as follows:

[0061] Step 1: Use the pulse voltage method to output a step voltage using the H-bridge and record the sampling period t s , when the current reaches 0.632IN (IN is the rated current), according to The inductance L is known, and the total resistance R1 of the first water leakage detection belt can be accurately calculated. After multiple measurements, the fluctuation μ1 of R1 can be calculated.

[0062] Step 2: Turn on the upper tube Q1 of bridge arm 1 and the lower tube Q4 of bridge arm 2 to collect current. Gradually increase the opening time of bridge arm 1 and bridge arm 2, and wait for the current to reach 1 / 2 of the rated current. Keep the duty cycle unchanged, collect the current and voltage at this time, and low-pass filter them respectively. After waiting for a certain period of time, record the filtered current i and voltage u, and calculate the total resistance R2=u / i of the second water leakage detection belt according to the direct Ohm method. Repeat the measurement and take the average value, measure multiple times, and calculate the fluctuation μ2 of R2.

[0063] Step 3: Calculate the total resistance R of the water leakage detection belt accurately by using the minimum error calculation method for R1 and R2:

[0064]

[0065] Step 4. After waiting for 10ms, repeat steps 1 to 3. When it is detected that the total resistance R becomes smaller, the leakage position is obtained according to the relationship table between resistance and distance, and then converted into a joint number, and the power supply of the joint is cut off to protect the equipment.

[0066] The accurate water leakage detection device and method based on parameter identification method proposed in the present invention are faster and more accurate than the existing water leakage detection methods, with detection time <100ms and detection accuracy <100cm. It is better than the commonly used detection accuracy of 2 to 5 meters. The complete method of parameter identification can be used to more completely and reasonably process the measurement data, which is more timely for the detection and protection of the underwater manipulator.

[0067] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0068] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. An accurate water leakage detection and positioning device, characterized in that: It includes accurate detection circuit, water leakage detection belt, detection controller and water leakage protection circuit; The precise detection circuit is used to detect the resistance of the water leakage detection belt, including a detection inductor, an H-bridge, a voltage acquisition circuit and a current acquisition circuit; the H-bridge DC input is connected to the power supply of the mechanical arm, and each bridge arm output is connected to the detection inductor and the water leakage detection belt in turn, the voltage acquisition circuit is used to collect the voltage between the two bridge arms, and the current acquisition circuit is used to collect the bridge arm current; The water leakage detection belt is composed of long strip resistors with uniform resistance. A water leakage detection belt is arranged at each joint of the robot arm, and all the water leakage detection belts are connected in series to form a loop; The detection controller is used to control the H-bridge to send voltage pulses to measure the resistance of the water leakage detection belt, sample voltage and current, confirm the distance by measuring the resistance, accurately calculate the location, and send out a protection signal; The water leakage protection circuit is composed of the power relay signal lines of each joint. After the detection controller detects water leakage, it sends a protection signal to the water leakage protection circuit of the corresponding joint and cuts off the power supply in sections.

2. The precise water leakage detection and positioning device according to claim 1, characterized in that: The H bridge is composed of four MOS tubes Q1 to Q4 with anti-parallel diodes, Q1 and Q2 form bridge arm 1, Q3 and Q4 form bridge arm 2, and the current collection circuit collects the current when the upper tube Q1 of bridge arm 1 is turned on and the lower tube Q4 of bridge arm 2 is turned on.

3. The precise water leakage detection and positioning device according to claim 2, characterized in that: The detection inductance has a value between 0.1 mH and 1 mH.

4. The precise water leakage detection and positioning device according to claim 2, characterized in that: The resistance of the water leakage detection belt is measured using the pulse voltage method as follows: according to Δi=i(n)-i(n-1),U=U N ·d, get Where: L is the detection inductance value, U N is the rated voltage, d is the given duty cycle, t s is the sampling period, i(n) is the current sampling value, and i(n-1) is the previous current sampling value.

5. The precise water leakage detection and positioning device according to claim 2, characterized in that: The resistance of the water leakage detection belt is still measured by the direct ohm method.

6. A precise water leakage detection and positioning method based on the device according to any one of claims 2 to 5, characterized in that: The following steps are involved: S1, using the pulse voltage method, using the H-bridge to output step voltage, record the sampling period t s , when the current reaches 0.632 times the rated current, according to Calculate the total resistance R1 of the first water leakage detection belt, measure it multiple times, and calculate the fluctuation μ1 of R1; L is the detection inductance value, U N is the rated voltage, d is the given duty cycle, i(n) is the current sampling value, and i(n-1) is the previous current sampling value; S2, turn on the upper tube Q1 of bridge arm 1, turn on the lower tube Q4 of bridge arm 2, collect current, gradually increase the opening time of bridge arm 1 and bridge arm 2, wait for the current to reach 1 / 2 of the rated current, keep the duty cycle unchanged, collect the current and voltage at this time, low-pass filter them respectively, record the filtered current i and voltage u, calculate the total resistance value R2=u / i of the second water leakage detection belt, repeat the measurement and take the average value, measure multiple times, and calculate the fluctuation amount μ2 of R2; S3. Calculate the total resistance R of the leakage detection belt accurately by using the minimum error calculation method for R1 and R2: S4. After the set waiting interval, repeat S1 to S3. When it is detected that the total resistance R becomes smaller, the leakage position is obtained by looking up the relationship table between resistance and distance, and then converted into a joint number, and the power supply of the joint is cut off to protect the equipment.

7. The accurate water leakage detection and positioning method according to claim 6 is characterized in that: The set waiting interval does not exceed 10ms.

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