A valve opening measurement device, a measurement method and a switch direction judgment method

Abstract

The present invention discloses a valve opening measurement device, a measurement method and a switch direction judgment method, wherein N magnetic parts are evenly arranged on the rotating shaft of the valve, and the rotating shaft is evenly divided into N first areas; M sensor switches are arranged on a circuit board and distributed on concentric circles with the center of the rotating shaft as the center; the sensor switch is used to detect the approach or distance of the magnetic part and output a magnetic induction signal, and the magnetic induction signal is input into a processor; the processor is used to process the magnetic induction signal, judge the valve switch direction and measure the valve opening; the beneficial effects of the present invention are that there is no requirement for the angular position of the initial state magnet relative to the center of the rotating shaft, and there is no need for technical installation personnel to control the angular position of the rotating shaft of the fire hydrant valve; a tunnel magnetoresistive sensor is used, which occupies less space, has higher sensitivity, and has good temperature stability and low power consumption characteristics; smaller initial angle error; and higher measurement step accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of valve opening, and in particular to a valve opening measuring device, a measuring method and a switching direction judging method. Background Art

[0002] Fire hydrant valves are used to open and close the water supply of fire hydrants. Measuring and reporting the valve opening can remotely monitor the water supply of fire hydrants. Combined with the information of fire hydrant managers, it can promptly determine whether there is any mistaken opening or illegal water extraction, reduce monitoring and maintenance investment, protect water resources and reduce losses.

[0003] The current fire hydrant valve opening measurement technology mainly uses reed switches as sensor switches and magnet blocks as magnetic parts. Two pairs of sensor switches are used to sense the magnetic parts on the valve shaft to generate opening and closing signals respectively, and the opening of the valve shaft is calculated by the number of opening and closing signals generated. The main problems of this solution are: the initial position of the fire hydrant valve shaft needs to be limited, and the initial position of the magnetic part on the shaft ring cannot be within the fan-shaped range with a smaller angle between the two sets of sensor switches. The technicians need to ensure this during installation, otherwise it will cause a large error in the shaft opening result; the initial error is large. When 4 magnetic parts are used on the ring and the entry angle of the magnetic parts and the sensor switch is 20°, the maximum initial error can reach more than 50°; the step accuracy of the valve shaft opening test is poor, and can only be superimposed and counted at 90° (4 magnetic parts on the ring), 120° (3 magnetic parts on the ring), and 180° (2 magnetic parts on the ring); the AT value range of the reed switch is large, which is not suitable for product design with a small error range. The wide AT range of the reed switch easily leads to the aliasing of the sensing areas of adjacent magnetic parts. When the number of distributed magnetic parts needs to be increased to improve the valve opening detection accuracy, it is difficult to ensure consistency, and the difficulty of implementation increases.

[0004] In view of this, this application is hereby filed. Summary of the invention

[0005] The technical problem to be solved by the present invention is that the valve opening measurement in the prior art is inaccurate and has a large error range; the purpose is to provide a valve opening measuring device, a measuring method and a switch direction judgment method, which can improve the accuracy of valve opening measurement, have higher measurement sensitivity, and reduce the initial error.

[0006] The present invention is achieved through the following technical solutions:

[0007] A valve opening measuring device comprises M sensor switches and N magnetic parts, M>=3, N>=1, M and N are positive integers, the N magnetic parts are evenly arranged on the rotating shaft of the valve, and the rotating shaft is evenly divided into N first areas; the M sensor switches are arranged on a circuit board and distributed on concentric circles with the center of the rotating shaft as the center; the arc angle formed by the M sensor switches is smaller than the center angle of the first area, and the angle θ between any two adjacent sensor switches is the same;

[0008] The sensor switch is used to detect the magnetic field strength of the magnetic part approaching or moving away, and convert the magnetic field strength into a digital voltage signal and input it into the processor. The digital voltage signal is the magnetic induction signal;

[0009] The processor is used to process the magnetic induction signal, and based on the magnetic induction signal, determine the valve switch direction and measure the valve opening.

[0010] In the traditional method of measuring the opening of fire hydrant valves, a magnet block is used as a magnetic part, and two pairs of sensor switches are used to sense the magnetic parts on the valve shaft to generate valve opening and valve closing signals respectively, and the opening of the valve shaft is calculated through the number of opening and closing signals generated. However, when the traditional method is used to measure the valve opening, there are strict requirements on the initial installation position of the magnetic part. Exceeding the position will introduce a large error, increasing the difficulty of installation, and the traditional method has poor measurement accuracy and a large initial error, which ultimately makes the calculated opening inaccurate. The present invention provides a valve opening measuring device, which can achieve that when measuring the opening, it is not limited by the angular position of the initial magnetic part relative to the center of the shaft, and improves the accuracy of valve opening measurement.

[0011] Preferably, when the sensor switch detects that a magnetic part is approaching, an approach angle α between the two with the center of the rotating shaft as the center is smaller than a departure angle β when the sensor switch detects that the magnetic part is moving away, α<β, and θ<α+β.

[0012] Preferably, when the processor counts the two magnetic induction signals generated by the magnetic part approaching and moving away from the sensor switch, the specific expression of θ is: θ=360° / (2*M*N), and the entry angle α and the departure angle β satisfy α+β=360° / (2*N).

[0013] Preferably, when the processor only counts a magnetic induction signal generated when the magnetic part approaches or moves away from the sensor switch, the specific expression of θ is: θ=360° / (M*N), and the entry angle α and the departure angle β satisfy α+β<(360 / N)°.

[0014] Preferably, the sensor switch is a tunnel magnetoresistive sensor.

[0015] The present invention also provides a method for determining the switching direction of a valve. The method for determining the switching direction using the device as described above is as follows: detecting the order in which the M sensor switches sense the magnetic induction signals. If the M sensor switches sense and output the magnetic induction signals in a counterclockwise direction, the valve rotates counterclockwise; if the M sensor switches sense and output the magnetic induction signals in a clockwise direction, the valve rotates clockwise.

[0016] The present invention also provides a method for determining the valve switch direction. When α>θ, α+β<(360° / N)-θ; or when α<θ, θ<α+β<(360° / N)-θ, the method for determining the switch direction is implemented by using the device as claimed in claims 1, 2 and 4: detecting the level states of the M sensor switch outputs, and making a judgment based on the M level states of the M sensor switches at the same time.

[0017] The present invention also provides a method for measuring valve opening, which uses the result of determining the valve opening direction as described above to perform measurement, and when the processor counts two magnetic induction signals generated by the magnetic part approaching and moving away from the sensor switch, the specific method steps of the measurement include:

[0018] S1: Adjust the angles of θ and α+β so that θ=360° / (2*M*N), α+β=360° / (2*N);

[0019] S2: Close the valve, initialize the valve status, and the processor records the rotation angle back to 0;

[0020] S3: The valve is rotated to drive the magnetic part to rotate at the same angle. When the angle between the sensor switch and the magnetic part about the center of the rotating shaft changes from large to small and less than α, a level edge signal is output. When the angle changes from small to large to greater than β, the sensor switch outputs another level edge signal. The number of signal edges is recorded as a.

[0021] S4: Based on the determined valve opening and closing direction, a 360° / (2*M*N) angles are added, subtracted, and accumulated to obtain the valve opening.

[0022] The present invention also provides a method for measuring valve opening, which uses the result of determining the valve opening direction as described above to perform measurement, and when the processor only counts a magnetic induction signal generated when the magnetic part approaches or moves away from the sensor switch, the specific method steps of the measurement include:

[0023] S1: Adjust the angles of θ and α+β so that θ=360° / (M*N), α+β<(360 / N)°, preferably α+β=360° / (2*N);

[0024] S2: Close the valve, initialize the valve status, and the processor records the rotation angle back to 0;

[0025] S3: The valve is rotated to drive the magnetic part to rotate at the same angle. When the angle between the sensor switch and the magnetic part about the center of the rotating shaft changes from large to small and is less than α, a level edge signal is output, and the number of signal edges is recorded as b;

[0026] S4: Based on the determined valve opening and closing direction, b 360° / (M*N) angles are added, subtracted and accumulated to obtain the valve opening.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] 1. A valve opening measurement device, a measurement method and a switch direction judgment method provided by the embodiment of the present invention have no requirements on the angular position of the initial magnetic part relative to the center of the rotating shaft, and do not require technical installation personnel to control the angular position of the rotating shaft of the fire hydrant valve;

[0029] 2. A valve opening measurement device, a measurement method and a switch direction judgment method provided by an embodiment of the present invention use a tunnel magnetoresistance sensor, which occupies a smaller space, has a higher sensitivity, and has good temperature stability and low power consumption characteristics.

[0030] 3. The valve opening measurement device, measurement method and switch direction determination method provided by the embodiments of the present invention have significantly smaller initial angle error than traditional methods.

[0031] 4. The valve opening measurement device, measurement method and switch direction determination method provided by the embodiments of the present invention greatly improve the measurement step progress compared with the traditional method. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 This is a top view of the opening measurement device.

[0034] Reference numerals:

[0035] 1. Circuit board; 2. Sensor switch; 3. Magnetic part; 4. Shaft ring; 5. Shaft center. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0037] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is apparent to one of ordinary skill in the art that these specific details are not necessarily employed to practice the present invention. In other embodiments, in order to avoid obscuring the present invention, well-known structures, circuits, materials, or methods are not specifically described.

[0038] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment," "an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. In addition, it will be appreciated by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0039] In the description of the present invention, the directions or positional relationships indicated by terms such as “front”, “rear”, “left”, “right”, “up”, “down”, “vertical”, “horizontal”, “high”, “low”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the scope of protection of the present invention.

[0040] Embodiment 1

[0041] This embodiment discloses a valve opening measurement device, such as Figure 1As shown, it includes M sensor switches and N magnetic members 3, M>=3, N>=1, the N magnetic members 3 are evenly arranged on the rotating shaft ring 4 of the valve, and the rotating shaft ring 4 is evenly divided into N first areas; the M sensor switches are arranged on the circuit board 1, and are distributed on concentric circles with the center of the rotating shaft ring 4 as the center; the arc angle formed by the M sensor switches is smaller than the center angle of the first area, and the angle θ between any two adjacent sensor switches is the same; in this embodiment, M=3, N=4 is taken as an example to illustrate this embodiment The specific device in the example is composed of M (≥3) sensor switches 2. The sensor switch 2 used in this embodiment is preferably a tunnel magnetoresistance TMR. The tunnel magnetoresistance sensor occupies less space, has higher sensitivity, and has good temperature stability and low power consumption characteristics. It is composed of an MCU processor, N (≥1) magnetic parts 3 and a shaft ring 4 for placing the magnetic parts 3. At the same time, it is necessary to carry a circuit board 1 for the sensor switch 2 and the MCU, and place the valve end cover of the circuit board 1, which is installed on the top of the fire hydrant, and the shaft ring 4 for installing the magnetic part 3 is adapted to the fire hydrant valve shaft.

[0042] In this embodiment, there are 3N magnetic parts, 4 in this case, which are evenly spaced on the circular ring, with adjacent angles θ being 360° / N=90°. They are located on concentric circles with the central axis of the fire hydrant valve shaft as the center, and act as a magnetic source as the fire hydrant valve shaft ring 4 rotates.

[0043] When the sensor switch detects that a magnetic part is approaching, the entry angle α of the two with the center of the rotating shaft as the center is smaller than the departure angle β when the sensor switch detects that the magnetic part is moving away, that is, α<β, and θ<α+β. According to the basic principle that the induced magnetic force at the working point of the sensor switch 2 is greater than the induced magnetic force at the release point: α<β must be true. The magnetic part 3 approaches the sensor switch 2 as the valve rotates. When the angle is less than the entry angle α, the sensor switch 2 senses that the magnetic part 3 is approaching and outputs a signal edge, here taking the falling edge as an example; thereafter, the magnetic part 3 continues to rotate. When the magnetic part 3 gradually moves away from the sensor switch 2 and the angle is greater than the departure angle β, the sensor switch 2 senses that the magnetic part 3 is leaving and outputs another signal edge, here taking the rising edge as an example.

[0044] The sensor switch 2 is used to detect the magnetic field strength of the magnetic part 3 approaching or moving away, and convert the magnetic field strength into a digital voltage signal and input it into the processor. The digital voltage signal is the magnetic induction signal; the processor is used to process the magnetic induction signal, and based on the magnetic induction signal, determine the valve switch direction and measure the valve opening.

[0045] There are 2M sensor switches, 3 here, which are ABC in clockwise direction, and the adjacent angles are the same as θ. The sensor switch 2 is placed on the circuit board 1, on the concentric circle with the central axis of the fire hydrant valve shaft ring 4 as the center, the radius r from the magnetic part 3 to the center of the shaft ring 4 and the radius R from the sensor switch 2 to the center of the shaft ring 4. By adjusting r and R, the minimum distance between the magnetic part 3 and the sensor switch 2 can be adjusted, and then the approach angle α and the departure angle β can be adjusted to avoid the situation that the magnetic part 3 cannot be sensed to approach or cannot be sensed to leave during the rotation process;

[0046] In this embodiment, two stepping precision measurements can be implemented according to whether the MCU counts two magnetic induction signals (falling edge and rising edge) output by the sensor switch 2 or only counts one magnetic induction signal (falling edge or rising edge):

[0047] Step accuracy 1: When the MCU processor counts the two magnetic induction signals generated by the magnetic part 3 approaching and moving away from the sensor switch 2, the example here is that the magnetic part 3 approaches the sensor switch 2 to generate a falling edge signal, and moves away from the sensor switch 2 to generate a rising edge signal. When the specific expression of θ is: θ = 360° / (2*M*N), the entry angle α and the departure angle β satisfy α+β=360° / (2*N); 360° / (2*M*N) is the highest step accuracy, which is equal to the value of θ. In order to achieve the highest accuracy, all effective edges need to be evenly divided into the coverage angle of the same magnet rotation cycle. To analyze the rotation process of the shaft ring 4, first, the circumference of 360° is divided into N large parts (a magnet rotation cycle).

[0048] Then, the M sensor switches 2 output one edge (such as a falling edge) one by one, and then output another edge (rising edge) one by one. At this time, each large portion needs to be divided into two parts (divided by 2) when it is divided by the M sensor switches 2. One part includes one edge of the M sensor switches 2, such as a falling edge, and the other part includes another signal edge of the M sensor switches 2, such as a rising edge. Taking the counterclockwise rotation of the shaft as an example, when the angle is 0°, the first sensor switch C senses that the magnetic part 2 is approaching and outputs a falling edge. Then the angle α+β is the starting point of the first sensor switch C generating a rising edge. According to geometric analysis, to achieve this division, α+β=360° / (2*N). At this time, the corresponding angle between each two effective edges is 360° / (2*N*M), which is the highest accuracy. When this embodiment is used, the initial error can be reduced to about 360° / (2*M*N), and the step accuracy can reach about 360° / (2*M*N).

[0049] Step accuracy 2: When the MCU processor only counts a magnetic induction signal generated when the magnetic part 3 approaches or moves away from the sensor switch 2, the falling edge signal generated when the magnetic part 3 approaches the sensor switch 2 is taken as an example. When the specific expression of θ is: θ=360° / (M*N), the entry angle α and the departure angle β satisfy α+β<(360 / N)°, preferably α+β=360° / (2*N); to ensure that the sensor switch 2 can sense the approach of the magnetic part 3, it is necessary for the magnetic switch to sense the departure of the magnetic part 3, otherwise the sensor switch 2 will always remain in the state where the magnetic part 3 approaches, and no signal edge will be generated. To meet this condition, according to the analysis of geometric figures, it is required that α+β cannot exceed 360° of the circumference by N The sector angle after equal division is α+β<360° / N; and the closer α+β is to 360° / N, the shorter the time that the same sensor switch 2 is away from the magnetic part 3 and the longer the time that it is close to the magnetic part 3 in the cycle of approaching and moving away from the magnetic part 3, that is, the higher the ground level duty cycle of the magnetic induction signal and the lower the high level duty cycle; the closer α+β is to 0°, the longer the time that it is away from the magnetic part 3 and the shorter the time that it is close to the magnetic part 3, that is, the lower the ground level duty cycle of the magnetic induction signal and the higher the high level duty cycle. Considering the influence of the consistency fluctuation of the device, the middle value of 360° / (2*N) is taken, and the system is the most robust. In this embodiment, the initial error can be reduced to about 360° / (M*N), and the step accuracy can reach about 360° / (M*N).

[0050] Due to individual differences, the initial states of the valve shafts 4 are different, and the initial positions of the corresponding magnetic bodies 3 relative to the sensor switch 2 are also uncertain. The calculation of the valve opening is based on the first effective edge as the 0 angle position, and then the subsequent sensed rotation angle is superimposed. Therefore, from the initial state to the time when the sensor switch 2 generates the first effective edge signal, the rotation of the valve cannot be sensed. This unsensed angle range is the initial position error. The maximum initial error can be obtained by analysis, which is actually the maximum rotation angle of the valve between the two effective edges, that is, the step accuracy: Step accuracy scheme 1: Maximum initial error = 360° / (2*M*N), step accuracy scheme 2: Maximum initial error = 360° / (M*N).

[0051] Therefore, by using a valve opening measuring device provided in this embodiment, it is achieved that when measuring the opening, there is no requirement for the angular position of the initial state magnet relative to the center of the shaft, and technical installation personnel are not required to control the angular position of the fire hydrant valve shaft ring 4, and the accuracy of the valve opening measurement is greatly improved.

[0052] Embodiment 2

[0053] This embodiment discloses a method for determining the opening and closing direction of a valve. This embodiment is to implement the method of the device as described in the first embodiment:

[0054] Detect the order of the same-nature magnetic induction signals sensed by the M sensor switches 2, such as the order of falling edges or the order of rising edges. If the M sensor switches 2 sense and output the magnetic induction signals in a counterclockwise direction, the valve rotates counterclockwise; if the M sensor switches 2 sense and output the magnetic induction signals in a clockwise direction, the valve rotates clockwise. Detect the order of the effective edges. Taking M=3 as an example, if the order of the rising edge or falling edge detected is CB, BA, AC, it is counterclockwise (open); AB, BC, CA is clockwise (closed); and so on when M is larger.

[0055] When the valve switch performs a back-and-forth switch action within an angle range less than θ, which causes the same sensor switch 2 to repeatedly generate valid signal edges, it needs to be identified and processed separately. At this time, according to whether the implementation scheme is the step accuracy scheme 1 or the step accuracy scheme 2 in the first embodiment, there are two cases:

[0056] Stepping accuracy scheme 1:

[0057] When the MCU processor counts the two magnetic induction signals generated by the magnetic part 3 approaching and moving away from the sensor switch 2, when monitoring the outputs of M sensor switches 2 at the same time, if the same sensor switch 2 first outputs one edge (such as a falling edge) and then outputs another edge (a rising edge), while other sensor switches 2 do not move, it indicates that the valve has a small movement of opening first and then closing or closing first and then opening in a small range. This small range is the angle θ of the adjacent sensor switches 2 = 360° / (2*M*N). At this time, when calculating the valve opening, it is considered that the two edges can offset each other and the opening change is not taken into account. Approaching and then moving away is equivalent to not approaching.

[0058] Stepping accuracy scheme 2:

[0059] When the MCU processor only counts one magnetic induction signal generated by the magnetic component 3 approaching or moving away from the sensor switch 2, when simultaneously monitoring the outputs of M sensor switches 2, if the same sensor switch 2 continuously has valid edges while other sensor switches 2 have no valid edges, it indicates that the valve has an action of opening first, then closing, and then opening, or closing first, then opening, and then closing in a small range. This small range is the angle θ=360° / (M*N) between adjacent sensor switches 2. When calculating the valve opening, this type of edge is considered to be a repeated action. When the same sensor switch 2 continuously outputs more than one valid edge, it is counted as one time.

[0060] Embodiment 3

[0061] This embodiment discloses a method for determining the direction of valve opening and closing. This embodiment is to realize the method of the second stepping accuracy scheme in the first embodiment:

[0062] In the second stepping precision scheme, the MCU processor only counts a magnetic induction signal generated by the magnetic part 3 approaching or moving away from the sensor switch 2. Here, the falling edge signal generated by the magnetic part 3 approaching the sensor switch 2 is taken as an example; the level state of the M sensor switches 2 outputs is detected, and the judgment is made based on the M electrical frequency states of the M sensor switches 2 at the same time. The specific method is that when a sensor switch 2 outputs an effective edge, the level state of the outputs of other sensor switches 2 is detected. Taking M=3 as an example, the various states of the clockwise and counterclockwise rotation of the fire hydrant valve shaft ring 4 are analyzed, and the state list of the output levels of the three magnetic control switches is obtained when all effective edges are generated. According to the state list, it can be known that under certain restrictions, when the output level of any one of the three magnetic control switches is flipped, the level values ​​output by the other two magnetic control switches are determined and opposite in clockwise and counterclockwise. Therefore, the MCU can detect the level state of the outputs of the other two magnetic control switches when any effective edge is detected, and the direction can be determined.

[0063] The restriction condition required by this method is: when the magnetic member 3 approaches / moves away from a sensor switch 2 in one direction to trigger its output valid edge, the state of the previous sensor switch 2 in this direction is that it has approached / moved away, and the state of the next sensor switch 2 is that it has not approached / moved away. In this way, when a sensor switch 2 triggers an effective edge, the state levels of the left and right sensor switches 2 will be opposite depending on whether it is triggered counterclockwise or clockwise. Figure 1 As shown, take the valve shaft ring 4 as an example of counterclockwise rotation, and require that when C triggers the falling edge, B is high level (not close yet), A is low level (already close), and when C triggers the falling edge clockwise, B is low level (already close), A is high level (not close yet). According to geometric analysis, the trigger sensor switch 2 is listed as the leftmost (such as Figure 1 A), the rightmost (such as Figure 1 C), and intermediate (such as Figure 1 In the three scenarios of B), the next switch is not close / far away yet, and the previous switch is close / far away. The required mathematical conditions are the intersection, that is, when α>θ, α+β<(360° / N)-θ, and when α<θ, θ<α+β<(360° / N)-θ. This restriction must be met for this method to be used.

[0064] When M=3, the relationship between the shaft rotation direction and the sensor switch output level is shown in the following table, 1 represents a high level and 0 represents a low level:

[0065]

[0066] Embodiment 4

[0067] This embodiment discloses a valve opening measurement method. This embodiment is based on the device of the first embodiment and the result of judging the switch direction of the second embodiment. When the MCU processor counts the two magnetic induction signals generated when the magnetic part 3 approaches and moves away from the sensor switch 2, a valve opening measurement method is implemented. Here, the magnetic part 3 approaches the sensor switch 2 to generate a falling edge signal, and moves away from the sensor switch 2 to generate a rising edge signal. According to Figure 1 , M=3,N=4.

[0068] The specific steps of the measurement include:

[0069] S1: Adjust the angle of θ so that θ=360° / (2*M*N); adjust the lengths of R and r so that α+β=360° / (2*N); Figure 1 In the device shown, θ = 15°, α + β = 360° / (2*N) = 45°;

[0070] S2: After the fire hydrant is installed and the valve is closed, it is reset to the initial state, and the processor records the rotation angle as 0;

[0071] S3: The valve is rotated to drive the magnetic part to rotate at the same angle. When the angle between the sensor switch and the magnetic part about the center of the rotating shaft changes from large to small and becomes less than α, the sensor switch outputs a falling edge. When the angle changes from small to large and becomes greater than β, the sensor switch outputs a rising edge. The number of valid edges is recorded as a.

[0072] S4: Each valid edge represents a valve rotation of 360° / (2*M*N)=15°. The valve opening can be obtained by adding or subtracting the number of all detected signal edges*15° according to the determined valve opening and closing direction.

[0073] Embodiment 5

[0074] This embodiment discloses a valve opening measurement method. This embodiment is based on the device of the first embodiment and the switch direction determination result of the second or third embodiment. When the MCU processor only counts a magnetic induction signal generated when the magnetic part 3 approaches or moves away from the sensor switch 2, a valve opening measurement method is implemented. Here, only counting the falling edge signal generated when the magnetic part 3 approaches the sensor switch 2 is taken as an example. Figure 1 , M=3,N=4.

[0075] The specific steps of the measurement include:

[0076] S1: Adjust the angle of θ so that θ = 360° / (M*N), such as Figure 1 As shown, θ=360° / (M*N)=30°; adjust the lengths of R and r so that α+β=360° / (2*N), α+β=360° / (2*N)=45°;

[0077] S2: After the fire hydrant is installed and the valve is closed, it is reset to the initial state, and the processor records the rotation angle as 0;

[0078] S3: The valve is rotated to drive the magnetic part to rotate at the same angle. When the angle between the sensor switch and the magnetic part about the center of the rotating shaft changes from large to small and is less than α, a falling edge is output, and the number of falling edges is recorded as b;

[0079] S4: Each falling edge represents a valve rotation of 360° / (M*N)=30°. The valve opening can be obtained by adding or subtracting the number of all detected falling edges*30° according to the determined valve opening and closing direction.

[0080] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for measuring valve opening, characterized in that: The valve opening measuring device comprises M sensor switches and N magnetic parts, M>=3, N>=1, M and N are positive integers, the N magnetic parts are evenly arranged on the rotating shaft of the valve, and the rotating shaft is evenly divided into N first areas; the M sensor switches are arranged on a circuit board, and are distributed on concentric circles with the center of the rotating shaft as the center; the arc angle formed by the M sensor switches is smaller than the center angle of the first area, and the angle θ between any two adjacent sensor switches is the same; The sensor switch is used to detect the magnetic field strength of the approaching or moving away magnetic part, and convert the magnetic field strength into a digital voltage signal and input it into the processor, wherein the digital voltage signal is a magnetic induction signal. At the same time, when the sensor switch detects that a magnetic part approaches with the rotating shaft, the approach angle between the two with the center of the rotating shaft as the center and the line connecting the center of the circle as the edge is recorded as α, and when the sensor switch detects that a magnetic part moves away with the rotating shaft, the departure angle between the two with the center of the rotating shaft as the center and the line connecting the center of the circle as the edge is recorded as β; The processor is used to detect the level states of the outputs of the M sensor switches, and judge the valve switch direction based on the level states of the M sensor switches at the same time, wherein the order in which the M sensor switches sense the magnetic induction signals is detected. If the M sensor switches sense and output the magnetic induction signals in a counterclockwise direction, the valve rotates counterclockwise; if the M sensor switches sense and output the magnetic induction signals in a clockwise direction, the valve rotates clockwise; Furthermore, when the processor counts the two magnetic induction signals generated when the magnetic part approaches and moves away from the sensor switch, the angle θ is adjusted to α+β so that the angle θ=360° / (2*M*N), α+β=360° / (2*N), and the valve is closed to initialize the valve state. The processor records the rotation angle as 0, and then drives the magnetic part to rotate at the same angle by rotating the valve. When the angle between the sensor switch and the magnetic part about the center of the rotating shaft changes from large to small to less than α, a level edge signal is output. When the angle changes from small to large to greater than β, the sensor switch outputs another level edge signal. The total number of signal edges when the angle changes from large to small to less than α and when the angle changes from small to large to greater than β is recorded as a. Based on the judged valve switch direction, a 360° / (2*M*N) angles are added, subtracted, and accumulated to obtain the valve opening.

2. A valve opening measurement method according to claim 1, characterized in that: When the sensor switch detects that a magnetic part is approaching, an approach angle α between the two with the center of the rotating shaft as the center is smaller than a departure angle β when the sensor switch detects that the magnetic part is moving away, α<β, and θ<α+β.

3. A valve opening measurement method according to claim 2, characterized in that: When the processor counts the two magnetic induction signals generated by the magnetic part approaching and moving away from the sensor switch, the specific expression of the angle θ is: θ=360° / (2*M*N), and the entry angle α and the departure angle β satisfy α+β=360° / (2*N).

4. A valve opening measurement method according to claim 2, characterized in that: When the processor only counts a magnetic induction signal generated when the magnetic part approaches or moves away from the sensor switch, the specific expression of the angle θ is: θ=360° / (M*N), and the entry angle α and the departure angle β satisfy α+β<(360 / N)°.

5. A valve opening measurement method according to any one of claims 1 to 4, characterized in that: The sensor switch is a tunnel magnetoresistive sensor.

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