Liquid level detection circuit, method, liquid level meter, liquid storage tank and unmanned aerial vehicle

Abstract

The application provides a liquid level detection circuit, a method, a liquid level meter, a liquid storage tank and a UAV, and relates to the field of liquid level measurement. The liquid level detection circuit comprises a power supply unit, a detection branch, a first voltage dividing resistor and a second voltage dividing resistor; the two ends of the detection branch are connected in series with the first voltage dividing resistor and the second voltage dividing resistor respectively, and are connected to the power supply unit through the first voltage dividing resistor and the second voltage dividing resistor respectively; the detection branch comprises a detection resistor and a plurality of detection units, and the detection resistor and the plurality of detection units are electrically connected between the first voltage dividing resistor and the second voltage dividing resistor in sequence; the detection branch is used for detecting liquid levels of different heights, and the two ends form a first signal output end and a second signal output end for outputting liquid level detection signals respectively.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of liquid level measurement, and in particular, to a liquid level detection circuit, a method, a liquid level meter, a liquid storage tank and a UAV. BACKGROUND

[0002] The liquid level meter is widely used in the storage and transportation system of the petroleum, chemical industry, edible oil, beverage, brewing and other industries. By measuring the liquid level in various tank bodies, the purpose of measuring the stored and transported liquid is achieved.

[0003] The conventional liquid level meter includes a float and a liquid level detection circuit. The liquid level detection circuit includes a plurality of sensing switches and a plurality of connecting resistors. The float is provided with a magnetic element and can float on the liquid surface. When the sensing switch senses the magnetic element, the circuit is turned on, and the liquid level detection circuit outputs a liquid level signal. The liquid level information can be obtained through the liquid level detection signal.

[0004] However, if a sensing switch in the liquid level detection circuit fails and is connected to the ground when no magnetic element is sensed, the liquid level signal will not change even when the liquid level changes, resulting in failure to detect any liquid level information. SUMMARY

[0005] The present application provides a liquid level detection circuit, a method, a liquid level meter, a liquid storage tank and a UAV, which can detect the correct liquid level value even when any detection unit in the liquid level detection circuit fails.

[0006] To achieve the above-mentioned purpose, the technical solutions adopted by the embodiments of the present application are as follows:

[0007] In a first aspect, the embodiments of the present application provide a liquid level detection circuit, which includes a power supply unit, a detection branch, a first voltage dividing resistor and a second voltage dividing resistor. The two ends of the detection branch are connected in series with the first voltage dividing resistor and the second voltage dividing resistor, respectively, and are connected to the power supply unit through the first voltage dividing resistor and the second voltage dividing resistor, respectively.

[0008] The detection branch includes a detection resistor and a plurality of detection units, which are connected in series between the first voltage dividing resistor and the second voltage dividing resistor. The detection branch is used to detect liquid levels of different heights, and the two ends thereof form a first signal output end and a second signal output end for outputting liquid level detection signals, respectively.

[0009] In a possible implementation, the detection units comprise inductive switches and connecting resistors, the detection units are electrically connected in sequence, one end of the inductive switch of the first detection unit is electrically connected between the detection resistor and the connecting resistor of the first detection unit, and the other end is grounded; one end of the inductive switch of the i-th detection unit is electrically connected between the connecting resistor of the (i-1)-th detection unit and the connecting resistor of the i-th detection unit, and the other end is grounded, i is an integer greater than 2; and the detection resistor is electrically connected with the first voltage dividing resistor.

[0010] In a possible implementation, the liquid level detection circuit further comprises a fault determination unit, which is electrically connected with the first signal output end and the second signal output end respectively.

[0011] The fault determination unit is configured to determine whether the detection branch is faulty according to the first liquid level signal output by the first signal output end and the second liquid level signal output by the second signal output end, and locate the detection unit that is faulty when it is determined that the detection branch is faulty.

[0012] In a possible implementation, the liquid level detection circuit further comprises a processor, which is electrically connected with the first signal output end and the second signal output end respectively.

[0013] The processor is configured to process the first liquid level signal output by the first signal output end and the second liquid level signal output by the second signal output end to obtain first liquid level information and second liquid level information, and / or the processor is configured to process the first liquid level signal output by the first signal output end and the second liquid level signal output by the second signal output end to obtain liquid level information of the measured liquid.

[0014] In a second aspect, an embodiment of the present application further provides a liquid level detection method, which is applied to the liquid level detection circuit and comprises the following steps.

[0015] Obtaining a first liquid level signal output by the first signal output end and a second liquid level signal output by the second signal output end.

[0016] Determining a current liquid level of the measured liquid according to the first liquid level signal and the second liquid level signal.

[0017] In a third aspect, an embodiment of the present application further provides a liquid level meter, which comprises:

[0018] A hollow float rod;

[0019] The liquid level detection circuit described above, which is installed inside the float rod;

[0020] A float is installed outside the float rod, and the float includes a magnetic element capable of triggering the detection unit, and the float can move in the vertical direction with the change of the liquid level, so that the magnetic element triggers the detection unit at the position where it is located, thereby measuring the liquid level.

[0021] In a fourth aspect, the embodiments of the present application further provide a liquid storage tank, comprising:

[0022] A tank body;

[0023] The liquid level detection circuit or the liquid level meter is arranged in the tank body.

[0024] In a fourth aspect, the embodiments of the present application further provide a UAV, comprising:

[0025] A fuselage;

[0026] The liquid level detection circuit or the liquid level meter or the liquid storage tank is arranged on the fuselage.

[0027] Compared with the prior art, the liquid level detection circuit, method, liquid level meter, liquid storage tank and UAV provided by the embodiments of the present application, the liquid level detection circuit comprises a power supply unit, a detection branch, a first voltage dividing resistor and a second voltage dividing resistor; the two ends of the detection branch are connected in series with the first voltage dividing resistor and the second voltage dividing resistor, and are connected to the power supply unit through the first voltage dividing resistor and the second voltage dividing resistor respectively; the detection branch comprises a detection resistor and a plurality of detection units, and the detection resistor and the plurality of detection units are electrically connected in sequence between the first voltage dividing resistor and the second voltage dividing resistor; the detection branch is used for detecting liquid levels of different heights, and the two ends form a first signal output end and a second signal output end for outputting liquid level detection signals respectively. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0029] Figure 1 The structural schematic diagram of the conventional liquid level meter provided by the embodiments of the present application.

[0030] Figure 2 The schematic diagram of the conventional liquid level detection circuit provided by the embodiments of the present application.

[0031] Figure 3 The schematic diagram of the liquid level detection circuit provided by the embodiments of the present application.

[0032] Figure 4 Fig. 2 is a schematic diagram of a liquid level detection circuit according to an embodiment of the present application.

[0033] Figure 5 Fig. 3 is a schematic diagram of a liquid level detection circuit according to an embodiment of the present application.

[0034] Figure 6 Fig. 4 is a schematic diagram of a liquid level detection circuit according to an embodiment of the present application.

[0035] Figure 7 Fig. 5 is a flowchart of a liquid level detection method according to an embodiment of the present application.

[0036] Figure 8 Fig. 6 is an example diagram of a liquid level detection circuit according to an embodiment of the present application.

[0037] Figure 9 Fig. 7 is a structural diagram of a liquid tank according to an embodiment of the present application.

[0038] Legend: 10 - conventional liquid level gauge; 20 - liquid level gauge; 30 - liquid tank; 100 - conventional liquid level detection circuit; 110 - float rod; 120 - float; 200 - liquid level detection circuit; 210 - power supply unit; 220 - detection branch; 230 - fault determination unit; 240 - processor; 300 - tank body. DETAILED DESCRIPTION

[0039] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings for the embodiments of the present application to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present application.

[0041] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0042] In the description of the present application, it is to be understood by those skilled in the art that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly understood by those skilled in the art, or the orientation or positional relationship commonly understood by those skilled in the art, only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0043] In addition, the terms "first", "second", "third" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0044] In the description of the present application, it is to be understood that, unless otherwise specified and limited, the terms "set", "mount", "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0045] Please refer to Figure 1 , Figure 1 The structure of the conventional liquid level meter 10 is shown. The conventional liquid level meter 10 includes a float rod 110, a float 120 sleeved on the float rod 110, and a conventional liquid level detection circuit 100 installed inside the float rod 110. The conventional liquid level detection circuit 100 includes a plurality of vertically arranged sensing switches, when the float 120 moves in the vertical direction with the change of the liquid level, the sensing switch at the corresponding height is triggered, thereby measuring the liquid level.

[0046] Based on the Figure 1 , please refer to Figure 2 , Figure 2 The schematic diagram of the conventional liquid level detection circuit 100 in the conventional liquid level meter 10 is shown. It includes: n sensing switches: sensing switch Q1~sensing switch Qn, n connecting resistors: connecting resistor R1~connecting resistor Rn, a voltage dividing resistor R0 and a power supply element. The signal output end is formed between the voltage dividing resistor R0 and the connecting resistor R1, which is used to output the voltage value, that is, the liquid level signal. According to the liquid level signal, the liquid level value can be obtained.

[0047] When the inductive switches of different heights are triggered, the signal output end outputs different liquid level signals. When a certain inductive switch is triggered by the float, the corresponding relationship between the voltage value output by the signal output end when each inductive switch is triggered and the liquid level value corresponding to the inductive switch is established in advance, so that the liquid level value can be obtained.

[0048] For example, the voltage provided by the power supply element is v, and the resistance values of the voltage dividing resistor and each connection resistor are r. When the mth inductive switch Qm senses the float 120 and the liquid level detection circuit is turned on, the voltage value output by the signal output end is: Figure 2

[0049] In the above, m is an integer greater than 0 and less than n.

[0050] Then, by querying the conversion table of the voltage value and the liquid level value established in advance, the voltage value v x corresponding to the liquid level value is obtained.

[0051] When a certain inductive switch fails, for example, as shown in

[0052] , assuming that the switch Q2 is short-circuited, it is always in the on state and grounded, which in turn causes Q3-Qn to be short-circuited. At this time, if the float 120 is located between Q3-Qn, the signal output by the traditional liquid level detection circuit 100 is always the signal corresponding to the switch Q2, that is, it is always considered that the position of the float 120 does not change, and the actual position of the float 120 cannot be detected, which in turn causes the output liquid level information to be incorrect. Figure 2

[0053] To solve the above problems, the embodiment provides a liquid level detection circuit 200. On the basis of the traditional liquid level detection circuit 100, a detection resistor and a voltage dividing resistor are added, and a signal output end for outputting a liquid level signal is formed between the added detection resistor and voltage dividing resistor, so that the liquid level detection circuit 200 is symmetrical. In this way, in the case that any one inductive switch in the liquid level detection circuit 200 fails, correct liquid level information can still be detected.

[0054] Please refer to Figure 3 , Figure 3 The structure of the liquid level detection circuit 200 provided by the embodiment is shown. The liquid level detection circuit 200 includes a power supply unit 210, a detection branch 220, a first voltage dividing resistor Rl and a second voltage dividing resistor Rm. The two ends of the detection branch 220 are connected in series with the first voltage dividing resistor Rl and the second voltage dividing resistor Rm, and are connected to the power supply unit 210 through the first voltage dividing resistor Rl and the second voltage dividing resistor Rm, respectively.

[0055] ​The detection branch 220 comprises a detection resistor Rx and a plurality of detection units, the detection resistor Rx and the plurality of detection units are electrically connected between the first voltage dividing resistor Rl and the second voltage dividing resistor Rm in sequence; the detection branch 220 is used for detecting liquid levels of different heights, and two ends form a first signal output end and a second signal output end for outputting liquid level detection signals respectively.

[0056] It can be understood that the power supply unit 210 can be one power supply element, or two power supply elements: a first power supply element and a second power supply element, the first power supply element is electrically connected with the first voltage dividing resistor Rl, and the second power supply element is electrically connected with the second voltage dividing resistor Rm, which is not limited here.

[0057] It should be noted that, Figure 3 The positions of the first voltage dividing resistor Rl and the second voltage dividing resistor Rm in the detection branch 220 can be interchanged, and correspondingly, the detection resistor Rx is located below the plurality of detection units.

[0058] Optionally, based on the detection branch 220, Figure 3 Please refer to the detection branch 220, Figure 4 The detection unit comprises an inductive switch and a connecting resistor, the plurality of detection units are electrically connected in sequence, one end of the inductive switch Q1 of the first detection unit is electrically connected between the detection resistor Rx and the connecting resistor R1 of the first detection unit, and the other end is grounded; one end of the inductive switch Qi of the i-th detection unit is electrically connected between the connecting resistor Ri-1 of the (i-1)-th detection unit and the connecting resistor Ri of the i-th detection unit, and the other end is grounded, i is an integer greater than 2; the detection resistor Rx is electrically connected with the first voltage dividing resistor Rl.

[0059] In this embodiment, the resistance values of the detection resistor and the plurality of connecting resistors can be the same or different. The detection resistor and the plurality of connecting resistors can be arranged at equal intervals or non-equal intervals in the vertical direction, which is not limited here.

[0060] The inductive switch can be a reed switch or a Hall sensor.

[0061] Optionally, based on the detection branch 220, Figure 4 Please refer to the detection branch 220, Figure 5 The liquid level detection circuit 220 further comprises a fault determination unit 230, the fault determination unit 230 is electrically connected with the first signal output end and the second signal output end respectively;

[0062] The fault determination unit 230 is used for determining whether the detection branch 220 is faulty according to the first liquid level signal output by the first signal output end and the second liquid level signal output by the second signal output end, and locating the detection unit which is faulty when it is determined that the detection branch 220 is faulty.

[0063] In this embodiment, the fault determination unit 230 can be a single-chip microcomputer or the like.

[0064] Optionally, on the basis of Figure 4 Figure 6 The liquid level detection circuit 200 further comprises a processor 240, which is electrically connected with the first signal output end and the second signal output end respectively.

[0065] The processor 240 is configured to process the first liquid level signal output by the first signal output end and the second liquid level signal output by the second signal output end to obtain the first liquid level information and the second liquid level information, and / or the processor 240 is configured to process the first liquid level signal output by the first signal output end and the second liquid level signal output by the second signal output end to obtain the liquid level information of the measured liquid.

[0066] In the embodiment, the processor 240 can comprise a first analog-to-digital converter ADC1 and a second analog-to-digital converter ADC2. The first analog-to-digital converter ADC1 is electrically connected with the first signal output end, and is configured to convert the first liquid level signal into the first liquid level information and display the first liquid level information. The second analog-to-digital converter ADC2 is electrically connected with the second signal output end, and is configured to convert the second liquid level signal into the second liquid level information and display the second liquid level information.

[0067] The first liquid level signal and the second liquid level signal are analog voltage signals, and the first liquid level information and the second liquid level information are digital voltage signals.

[0068] It can be understood that the processor 240 can also be a single-chip microcomputer, which is configured to process the first liquid level signal and the second liquid level signal to obtain the liquid level information of the measured liquid.

[0069] Optionally, the functions of the processor 240 and the fault determination unit 230 can be combined into one processing unit. It can be understood that the processing unit can process the first liquid level signal and the second liquid level signal to obtain the liquid level information of the measured liquid, and can also determine whether the detection branch 220 is faulty, and locate the faulty detection unit when it is determined that the detection branch 220 is faulty. Alternatively, the functions of the fault determination unit 230 can be incorporated into the processor 240, or the functions of the processor 240 can be incorporated into the fault determination unit without distinction.

[0070] On the basis of the liquid level detection circuit 200 provided in the above, the embodiment further provides a liquid level detection method applied to the liquid level detection circuit 200, please refer to Figure 7 The method comprises the following steps S110-S120.

[0071] S110, obtaining the first liquid level signal output by the first signal output end and the second liquid level signal output by the second signal output end.

[0072] ​S120, determining the current liquid level of the measured liquid according to the first liquid level signal and the second liquid level signal.

[0073] Optionally, the step S120 can include the following sub-steps S1201-S1204.

[0074] S1201, judging whether the detection branch 220 is faulty according to the first liquid level signal and the second liquid level signal.

[0075] Optionally, the sub-step S1201 can include the following detailed steps S1-S2.

[0076] S1, if one of the first liquid level signal and the second liquid level signal is fixed and the other changes in the continuous at least twice signal sampling, determining that the detection branch is faulty.

[0077] S2, if both the first liquid level signal and the second liquid level signal change in the continuous at least twice signal sampling, determining that the detection branch is not faulty.

[0078] S1202, if the detection branch 220 is faulty, taking the liquid level signal which changes in the first liquid level signal and the second liquid level signal in the continuous at least twice signal sampling as the first target liquid level signal.

[0079] In the embodiment, if the detection branch 220 is faulty, it is determined that the inductive switch in a certain detection unit of the detection branch 220 is faulty, so that the inductive switch is in the on state when there is no float induction.

[0080] When the float moves above the inductive switch, Figure 4 the first liquid level signal output by the first signal output end in the inductive switch is changed, and the current liquid level of the measured liquid can be obtained according to the first liquid level signal. The second liquid level signal output by the second signal output end is a fixed value, and the size is the voltage value corresponding to the faulty inductive switch.

[0081] When the float moves below the inductive switch, Figure 4 the second liquid level signal output by the second signal output end in the inductive switch is changed, and the first liquid level signal output by the first signal output end is a fixed value, and the size is the voltage value corresponding to the faulty inductive switch.

[0082] S1203, if the detection branch 220 is not faulty, taking any one of the first liquid level signal and the second liquid level signal in the continuous at least twice signal sampling as the first target liquid level signal.

[0083] In the embodiment, if the detection branch 220 does not fail, when the float moves in the vertical direction with the change of the liquid level, the first liquid level signal and the second liquid level signal change. Since the first liquid level signal and the second liquid level signal represent the voltages of different connection resistances, the values are different, and the current liquid level signal of the liquid to be detected can be obtained according to any one of the first liquid level signal and the second liquid level signal.

[0084] S1204, determining a target liquid level information table from the first liquid level information table and the second liquid level information table according to the first target liquid level signal, and determining the current liquid level corresponding to the first target liquid level signal from the target liquid level information table.

[0085] The first liquid level information table represents the correspondence between each first liquid level signal and each liquid level value, and the second liquid level information table represents the correspondence between each second liquid level signal and each liquid level value.

[0086] In the embodiment, for example, the voltage provided by the power supply unit 210 is 5V, the detection branch 220 includes four detection units and a detection resistance, the resistance values of the detection resistance and the connection resistances in the detection units are equal, and are both 1Ω. The resistance values of the first voltage dividing resistance Rl and the second voltage dividing resistance Rm are both 1Ω. The connection resistances and the detection resistance are arranged at equal distances, and the interval is 5cm. The interval between the range minimum point of the liquid level detection circuit 200 and the connection resistance R5 is 5cm.

[0087] The first liquid level information table can be shown in Table 1 as follows:

[0088] Table 1: First liquid level information table

[0089]

[0090] The second liquid level information table can be shown in Table 2 as follows:

[0091] Table 2: Second liquid level information table

[0092]

[0093] If the first target liquid level signal is the first liquid level signal, the liquid level value corresponding to the first liquid level signal in Table 1 is determined, that is, the current liquid level.

[0094] If the first target liquid level signal is the second liquid level signal, the liquid level value corresponding to the second liquid level signal in Table 2 is determined, that is, the current liquid level.

[0095] Optionally, after step S2, the following step S3 can be further included.

[0096] S3, when determining the failure of the detection branch, locating the detection unit that fails.

[0097] Optionally, step S3 can include steps S31-S32.

[0098] S31, from the first liquid level signal and the second liquid level signal, obtain a fixed and unchanging liquid level signal as the second target liquid level signal;

[0099] S32, according to the second target liquid level signal, determine the target fault information table from the pre-established first fault information table and the second fault information table, and locate the detection unit that fails from the target fault information table.

[0100] Wherein, the first fault information table represents the corresponding first liquid level signal when each detection unit fails, and the second fault information table represents the corresponding second liquid level signal when each detection unit fails.

[0101] In this embodiment, it is assumed that the voltage provided by the power supply unit 210 is 5V, the detection branch 220 includes detection unit 1-detection unit 4 and a detection resistor, wherein the resistance of the detection resistor and the connection resistance in the detection unit is equal, both are 1Ω, the resistance of the first voltage dividing resistor Rl and the second voltage dividing resistor Rm is 1Ω. The connection resistance and the detection resistance are arranged at equal distances, and the interval is 5cm. The interval between the range minimum point of the liquid level detection circuit 200 and the connection resistance R5 is 5cm.

[0102] Then the first fault information table can be shown in Table 3 as follows:

[0103] Table 3 first fault information table

[0104]

[0105] The second fault information table can be shown in Table 4 as follows:

[0106] Table 4 second fault information table

[0107]

[0108] In one possible situation, step S3 can also be implemented in the following way.

[0109] First, from the first liquid level signal and the second liquid level signal, obtain a fixed and unchanging liquid level signal as the second target liquid level signal.

[0110] Second, according to the second target liquid level signal, the pre-established first liquid level information table and the second liquid level information table determine the second target liquid level information table.

[0111] Third, according to the second target liquid level signal, determine the liquid level value corresponding to the second target liquid level signal in the second target liquid level information table, and determine the detection unit that fails corresponding to the liquid level value.

[0112] The working principle of the embodiment will be described below with a specific example.

[0113] As shown in the liquid level detection circuit 200, the detection branch 220 includes detection units 1-4 and a detection resistor Rx, wherein the detection resistor and the connection resistors R1-R4 have the same resistance value, i.e. 1Ω, and the first and second voltage dividing resistors Rl and Rm have the same resistance value, i.e. 1Ω. The first and second power supply elements provide a voltage of 5V. The connection resistors and the detection resistor are arranged at equal distances with an interval of 5cm. The interval between the lowest point of the range of the liquid level detection circuit 200 and the connection resistor R5 is 5cm. Figure 8

[0114] In the case where none of the detection units in the liquid level detection circuit 200 fails, when the float triggers the detection unit 3 in the detection branch 220 with the change of the liquid level, the liquid level detection circuit 220 is turned on. At this time, the first signal output end outputs the sum of the voltages of the detection resistor Rx, the connection resistor 1 and the connection resistor R2. The first signal output end outputs the sum of the voltages of the connection resistor R3 and the connection resistor R4.

[0115] Then, the first liquid level signal is:

[0116]

[0117] The second liquid level signal is:

[0118]

[0119] If the first liquid level signal is taken as the target liquid level signal, it can be determined from the aforementioned Table 1 that the liquid level value is 10cm.

[0120] If the second liquid level signal is taken as the target liquid level signal, it can also be determined from the aforementioned Table 2 that the liquid level value is 10cm.

[0121] In the case where the detection unit 2 in the liquid level detection circuit 200 fails, e.g. the inductive switch Q2 is short-circuited, even if the float is not at the inductive switch Q2, the liquid level detection circuit 200 is in the on state. At this time, if the float moves above the detection unit 2, only the first liquid level signal output by the first signal output end is changed, while the second liquid level signal output by the second signal output end is a fixed value.

[0122] Correspondingly, if the float moves below the detection unit 2, only the second liquid level signal output by the second signal output end is changed, while the first liquid level signal output by the first signal output end is a fixed value.

[0123] ​Thus, by collecting the first liquid level signal and the second liquid level signal, and observing whether the first liquid level signal and the second liquid level signal change, it can be determined whether the detection branch 220 fails.

[0124] When it is determined that the detection branch 220 fails, the liquid level signal that changes is taken as the target liquid level signal.

[0125] For example, the float moves above the detection unit 2 and triggers the detection unit 1. At this time, the first liquid level signal is the changing liquid level signal, and the second liquid level signal is the fixed value.

[0126] The first liquid level signal is:

[0127]

[0128] Further, by querying the information in Table 1, it is obtained that the liquid level value corresponding to the first liquid level signal is 20 cm.

[0129] In addition, the detection unit that fails can also be determined through the second liquid level signal.

[0130] The second liquid level signal is:

[0131]

[0132] Further, by querying Table 4, it is obtained that the detection unit that fails is the detection unit 2.

[0133] Compared with the prior art, the embodiment has the following beneficial effects:

[0134] Firstly, the liquid level detection circuit provided by the embodiment is symmetrical by increasing the detection resistor and the second liquid level signal output end, can output the first liquid level signal and the second liquid level signal at the same time, and can detect the correct liquid level information when one of the detection units in the detection branch fails.

[0135] In addition, whether the liquid level detection circuit fails can be determined according to the first liquid level signal and the second liquid level signal, and when the liquid level detection circuit is determined, the detection unit that fails can be located, without manual troubleshooting, and it is convenient for technicians to replace the detection unit in time.

[0136] The embodiment also provides a liquid level meter 20, which comprises: a hollow float rod, the liquid level detection circuit 200 is installed inside the float rod, a float, the float is installed outside the float rod, and the float comprises a magnetic element capable of triggering the detection unit, and the float can move in the vertical direction with the change of the liquid level to make the magnetic element trigger the detection unit at the position where the magnetic element is located, thereby measuring the liquid level.

[0137] Please refer to Figure 9 ,Figure 9 The liquid storage tank 30 provided by the embodiment is shown, which comprises a tank body 300, and the liquid level detection circuit 200 as described above or the liquid level meter 20 as described above arranged in the tank body 300. The embodiment also provides a UAV, which comprises a fuselage, and the liquid level detection circuit 200 as described above or the liquid level meter 20 as described above or the liquid storage tank 30 as described above arranged on the fuselage.

[0138] The above merely provides the preferred embodiments of the present application but is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modified, equivalent replaced, improved, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A liquid level detection circuit, characterized by, The liquid level detection circuit comprises a power supply unit, a detection branch, a first voltage dividing resistor and a second voltage dividing resistor; two ends of the detection branch are connected in series with the first voltage dividing resistor and the second voltage dividing resistor respectively, and are connected to the power supply unit through the first voltage dividing resistor and the second voltage dividing resistor respectively; The detection branch comprises a detection resistor and a plurality of detection units, the detection resistor and the plurality of detection units are electrically connected in sequence between the first voltage dividing resistor and the second voltage dividing resistor; the detection branch is used for detecting liquid levels of different heights, and two ends thereof form a first signal output end and a second signal output end respectively for outputting liquid level detection signals.

2. The liquid level detection circuit according to claim 1, characterized in that, The detection unit comprises an inductive switch and a connecting resistor, the plurality of detection units are electrically connected in sequence, one end of the inductive switch of the first detection unit is electrically connected between the detection resistor and the connecting resistor of the first detection unit, and the other end is grounded; one end of the inductive switch of the i-th detection unit is electrically connected between the connecting resistor of the (i-1)-th detection unit and the connecting resistor of the i-th detection unit, and the other end is grounded, i is an integer greater than 2; the detection resistor is electrically connected with the first voltage dividing resistor.

3. The liquid level detection circuit according to claim 1 or 2, characterized in that, The liquid level detection circuit further comprises a fault determination unit, and the fault determination unit is electrically connected with the first signal output end and the second signal output end respectively; The fault determination unit is used for determining whether the detection branch is faulty according to a first liquid level signal output by the first signal output end and a second liquid level signal output by the second signal output end, and locating the detection unit which is faulty when it is determined that the detection branch is faulty.

4. The liquid level detection circuit according to claim 1, characterized in that, The liquid level detection circuit further comprises a processor, and the processor is electrically connected with the first signal output end and the second signal output end respectively; The processor is used for processing the first liquid level signal output by the first signal output end and the second liquid level signal output by the second signal output end to obtain first liquid level information and second liquid level information, and / or the processor is used for processing the first liquid level signal output by the first signal output end and the second liquid level signal output by the second signal output end to obtain liquid level information of the measured liquid.

5. A liquid level detection method, characterized by, The method is applied to the liquid level detection circuit of any one of claims 1-4, and the method comprises: obtaining a first liquid level signal output by the first signal output end and a second liquid level signal output by the second signal output end; determining a current liquid level of the measured liquid according to the first liquid level signal and the second liquid level signal.

6. The method of claim 5, wherein, The step of determining the current liquid level of the measured liquid according to the first liquid level signal and the second liquid level signal comprises: determining whether the detection branch is faulty according to the first liquid level signal and the second liquid level signal; if yes, taking a liquid level signal which changes in the first liquid level signal and the second liquid level signal in at least two continuous signal sampling times as a first target liquid level signal; if no, taking any one of the first liquid level signal and the second liquid level signal in at least two continuous signal sampling times as the first target liquid level signal; According to the first target liquid level signal, a target liquid level information table is determined from a first liquid level information table and a second liquid level information table established in advance, and the current liquid level corresponding to the first target liquid level signal is determined from the target liquid level information table; The first liquid level information table represents the correspondence between each first liquid level signal and each liquid level value, and the second liquid level information table represents the correspondence between each second liquid level signal and each liquid level value.

7. The method of claim 6, wherein, The step of determining whether the detection branch fails according to the first liquid level signal and the second liquid level signal comprises: If one of the first liquid level signal and the second liquid level signal remains unchanged and the other changes in at least two consecutive signal sampling, it is determined that the detection branch fails; If both the first liquid level signal and the second liquid level signal change in at least two consecutive signal sampling, it is determined that the detection branch does not fail.

8. The method of claim 7, wherein, The method further comprises locating the failed detection unit when it is determined that the detection branch fails.

9. The method of claim 8, wherein, The step of locating the failed detection unit when it is determined that the detection branch fails comprises: Obtaining a liquid level signal that remains unchanged from the first liquid level signal and the second liquid level signal as a second target liquid level signal; According to the second target liquid level signal, a target fault information table is determined from a first fault information table and a second fault information table established in advance, and the failed detection unit is located from the target fault information table; The first fault information table represents the first liquid level signal corresponding to each detection unit failure, and the second fault information table represents the second liquid level signal corresponding to each detection unit failure.

10. A liquid level gauge, characterised in that, It comprises: A hollow float rod; The liquid level detection circuit of any one of claims 1-4 is installed inside the float rod; A float is installed outside the float rod, and the float comprises a magnetic element capable of triggering the detection unit, and the float can move in the vertical direction with the change of the liquid level to make the magnetic element trigger the detection unit at the position where it is located, thereby measuring the liquid level.

11. A reservoir tank characterized by It comprises: A box body: The liquid level detection circuit of any one of claims 1-4 or the liquid level meter of claim 10 is arranged in the box body.

12. A drone, characterized in that, It comprises: A fuselage; The liquid level detection circuit of any one of claims 1-4 or the liquid level meter of claim 10 or the liquid storage tank of claim 11 is arranged on the fuselage.

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