Cabin liquid level management system and method

Abstract

The invention relates to the technical field of ship equipment control, in particular to a cabin liquid level management system and method. The liquid level sensor comprises an external shell and a detection PCB (Printed Circuit Board) mounted in the external shell, and a plurality of capacitive liquid level sensors which are vertically arranged at intervals and are used for acquiring liquid level signals are arranged on the detection PCB; the liquid level detection circuit is arranged on the detection PCB and is connected with the capacitive liquid level sensor; the central control unit is connected with the liquid level detection circuit; the central control unit receives the liquid level signals, automatically obtains the duration time of the liquid level signals, judges whether the corresponding liquid level signals are effective or not according to the duration time, and generates a management action command if the corresponding liquid level signals are effective. The detection system in the management system can be arranged on the outer wall of a cabin to be detected for liquid level detection, so that the space in the cabin is saved; in addition, data interference caused by liquid level fluctuation changes can be eliminated, the actual liquid level height is accurately recognized, and the scientific rationality of subsequent water level management actions is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ship equipment control, and particularly to a cabin liquid level management system and method. Background Art

[0002] In the operation and management of waterborne power ships, the effective management of the liquid level in the cabin (such as the water level management of the ballast tank when the ship is empty) is directly related to the overall stability of the ship, the navigation efficiency, and the safety of crew members and cargo. During the navigation of the ship, with the changes in the loading volume, the fluctuations of sea conditions, and the use of consumables such as fuel and fresh water, the liquid level in the cabin will constantly change. The traditional liquid level management method mainly relies on manual monitoring by the crew. They need to regularly check the liquid level in the cabin and manually operate the water pump as needed to adjust the liquid level to ensure it is within the safe range.

[0003] However, this mode of manual monitoring and manual operation has many deficiencies. First, the manual monitoring is inefficient. The crew needs to frequently check the liquid level conditions in each cabin, which not only increases their work burden but also limits their focus on other key tasks. Second, manually operating the water pump is prone to errors due to human factors, such as untimely, excessive, or insufficient operation, which may cause abnormal liquid levels and thus pose a threat to the stability and navigation safety of the ship. Especially in bad weather or emergency situations, the limitations of manual monitoring and manual operation are more significant, and it may not be able to quickly respond to the liquid level changes, increasing the accident risk.

[0004] Therefore, with the development of ship automation technology, the traditional mode of manual monitoring and manual operation can no longer meet the requirements of modern ships for efficient, safe, and intelligent management. Therefore, automatic liquid level detection devices have been gradually introduced in practical applications. For example, the Chinese patent document with the publication number CN 118758400 A discloses a ship liquid level measurement system and its liquid level measurement method. This system includes a float type liquid level alarm sensor, an inner cabin liquid level height detection device arranged in the measured cabin, a draft height detection device arranged on the cabin, and a liquid level telemetry control box electrically connected to the float type liquid level alarm sensor, the inner cabin liquid level height detection device, and the draft height detection device respectively. It can monitor the liquid level in the ship's liquid tank in real time and give early warnings, and to a certain extent, it has successfully replaced manual monitoring and management.

[0005] However, in the above ship liquid level measurement system, the liquid level detection is mainly carried out by means of a mechanical float device, which has a complex structure. Moreover, this device needs to be placed inside the cabin to be measured and directly contacts the water body for detection operations. On the one hand, the detection device occupies valuable space inside the cabin to be measured, and the relatively complex structure and specific installation location bring problems of high failure rate and low maintainability; on the other hand, the ship is in a constantly shaking posture on the water surface, so the height of the measured liquid level in contact with the detection device will constantly change. Affected by this, the above-mentioned inner cabin liquid level height detection device cannot accurately judge the actual liquid level height, and ultimately leads to incorrect alarm timing. Summary of the Invention

[0006] The purpose of the present invention is to provide a cabin liquid level management system and method. The detection system in this management system can be placed on the outer wall of the cabin to be measured for liquid level detection, thereby saving space inside the cabin; this management system can also eliminate data interference caused by the fluctuating change of the liquid level surface, accurately identify the actual liquid level height, and improve the scientific rationality of subsequent water level management actions.

[0007] In order to achieve the above purpose, the specific technical solutions adopted by the present invention are as follows: A cabin liquid level management system includes an external housing, and is characterized in that it further includes a detection PCB board installed in the external housing. A plurality of capacitive liquid level sensors for obtaining liquid level signals are arranged on the detection PCB board, and the plurality of capacitive liquid level sensors are vertically arranged at intervals. The detection system further includes a liquid level detection circuit arranged on the detection PCB board and connected to the capacitive liquid level sensors, and a central control unit connected to the liquid level detection circuit. The central control unit receives the liquid level signal, automatically obtains the duration of the liquid level signal, and judges whether the corresponding liquid level signal is valid according to the duration. If it is valid, a management action command is generated; if it is invalid, it waits for the liquid level signal at the next moment.

[0008] The detection PCB board is installed in the external housing, and the external housing is installed on the outer wall of the measured cabin, closely fitting with the outer wall of the measured cabin without contacting the water body in the measured cabin. Multiple capacitive liquid level sensors for obtaining liquid level signals are arranged on the detection PCB board. The capacitive liquid level sensors can detect whether the liquid level reaches their own installation height through a medium (non-metallic medium). On the detection PCB board, each capacitive liquid level sensor can be exposed through a windowing process (without applying green oil), and then fit with the non-metallic induction area reserved on the outer wall of the measured cabin. Each windowing position on the detection PCB board is correspondingly provided with a capacitive liquid level sensor, and each windowing position is arranged at intervals in the vertical height direction, so that multiple capacitive liquid level sensors are vertically spaced. When the capacitive liquid level sensors at different heights detect that there is liquid behind the cabin wall, a liquid level signal is sent to the liquid level detection circuit electrically connected to it.

[0009] The liquid level detection circuit is composed of a liquid level detection chip and an auxiliary circuit, and it integrates multiple liquid level detection channels, corresponding to each capacitive liquid level sensor respectively. For example, when the liquid level detection circuit is composed of a four-channel liquid level detection chip U2, its four input pins correspond to CH1 to CH4, and are respectively connected to four capacitive liquid level sensors arranged at different height positions. After the capacitive liquid level sensor sends a liquid level signal, the four-channel liquid level detection chip U2 transmits the signal to the central control unit through OUT1 to OUT4 correspondingly.

[0010] The central control unit mainly includes a single-chip microcomputer U1. When the single-chip microcomputer U1 receives the corresponding voltage signal, it will judge whether the liquid level signal is valid based on the program burned in itself. Specifically, the single-chip microcomputer U1 will time the duration of the signal according to the built-in timer in itself, and obtain the voltage duration when the input pin receives the liquid level signal. After obtaining the duration, it will compare the duration with the set threshold time length of the capacitive liquid level sensor corresponding to this pin according to the automatic program. If the duration is greater than or equal to the set threshold time of the capacitive liquid level sensor corresponding to this pin, it means that the liquid level has indeed reached the installation height of this capacitive liquid level sensor, rather than being accidentally reached due to the shaking of the liquid surface. At this time, the central control unit judges that this liquid level signal is valid, and then the single-chip microcomputer U1 generates a warning action command to direct the subsequent warning behavior; if the time comparison fails, the central control unit judges that this liquid level signal is invalid, and this liquid level signal is triggered due to the shaking of the liquid surface, and the actual liquid level height has not reached the installation height of this capacitive liquid level sensor, then the single-chip microcomputer U1 will not generate a warning action command and enter the silent state, waiting for the arrival of the liquid level signal at the next moment.

[0011] In summary, through the integrated arrangement of the PCB board for the capacitive liquid level sensor, the liquid level detection circuit, and the central control unit, and the application of the capacitive liquid level sensor with the ability to sense across the bulkhead, the present invention can achieve mechanical structure-free detection. Moreover, the overall circuit hardware structure is integrated in the external housing, which not only does not occupy the space inside the measured ship's cabin but also has a very small occupancy rate of the space outside the measured ship's cabin. In addition, based on the circuit pin arrangement of the single-chip microcomputer applied in the central control unit and the judgment of the preset program, and by means of the chip-internal timer to measure the time duration value, the present detection system can distinguish whether the liquid level height corresponding to the received liquid level signal is the true liquid level height or the false height caused by the liquid surface fluctuation. By cooperating with the operation of discarding the latter signal, the scientific rationality of the management action command issued by the central control unit is ensured, greatly improving the practical application value of the present system.

[0012] Preferably, a voltage follower circuit for isolation and buffering is further provided between the liquid level detection circuit and the central control unit, and the voltage follower circuit includes a plurality of operational amplifiers.

[0013] The voltage follower circuit serves as an isolation and buffering stage, and its function is to provide a circuit interface with a high input impedance and a low output impedance, thereby reducing the impact interference of the central control unit on the aforementioned capacitive liquid level sensor and improving the judgment accuracy of the central control unit. As Figure 2 shown, the voltage follower circuit includes four operational amplifiers U3A, U4A, U5A, and U6A. Their respective input terminals are connected to the OUT1, OUT2, OUT3, and OUT4 terminals of the four-channel liquid level detection chip U2. The inverting terminal and the output terminal of each operational amplifier are directly connected to convert the input voltage into an output voltage signal with a low output impedance and the same amplitude and frequency. The output terminals CH1_OUT1, CH2_OUT2, CH3_OUT3, and CH4_OUT4 of each operational amplifier are connected to PA9, PB1, PB2, and PB3 of the single-chip microcomputer U1 respectively.

[0014] Preferably, this kind of ship's cabin liquid level management system further includes an execution unit connected to the central control unit, and the execution unit includes a sound reminder device, a light reminder device, and a drainage device.

[0015] The execution unit is the execution unit for ship's cabin liquid level management. It is connected to the central control unit and receives the management action command issued by the central control unit. It includes a sound reminder device, a light reminder device, and a drainage device. The former two are used for warning and reminder to help the crew quickly master the water level dynamics. The drainage device is used to automatically pump the rising water level in the ship's cabin to the outer compartment without manual intervention to ensure the safety of the water level.

[0016] As a preference of the present invention, the sound reminder device includes a buzzer and a first switch circuit connected to the buzzer for controlling the on / off of the buzzer.

[0017] The sound reminder device includes a buzzer that can emit a reminder sound after being powered on, and a first switch circuit for controlling the on / off of the buzzer. The first switch circuit can use a switching tube component. The voltage input terminal for controlling the on / off of the switching tube is connected to the output terminal of the central control unit. When the central control unit outputs a continuous high-level voltage signal to the switching tube, the switching tube conducts, enabling the buzzer to be powered on and continuously emit sound. The central control unit can control the sounding duration of the buzzer according to the output time of the high-level voltage signal to distinguish alarms for different water levels.

[0018] As a preference of the present invention, the drainage device includes a water pump and a second switch circuit connected to the water pump for controlling the opening / closing of the water pump.

[0019] The drainage device includes a water pump that can perform a pumping action driven by a motor after being powered on and a second switch circuit connected to the water pump for controlling the opening / closing of the water pump. The second switch circuit can use a switching tube component. When the central control unit outputs a continuous high-level voltage signal to the switching tube, the switching tube conducts, enabling the water pump to be powered on and perform the pumping action.

[0020] As a preference of the present invention, the central control unit includes a single-chip microcomputer U1 and a filter capacitor connected to the single-chip microcomputer U1. The single-chip microcomputer U1 is built-in with a timer, and the timer is used to automatically calculate the duration of the voltage signal received by the input pin.

[0021] The single-chip microcomputer U1 is built-in with a timer, and the timer is used to automatically calculate the duration of the voltage signal received by the input pin to perform a secondary judgment on the liquid level signal obtained at the input end. Only when the liquid level signal meets the time requirement is it considered a valid signal, thereby excluding the short-time triggered pseudo-liquid level signal caused by the liquid level fluctuation due to the ship's hull shaking.

[0022] As a preference of the present invention, the sound reminder device further includes a discharge resistor connected in parallel with the buzzer, and the discharge resistor is used for pressure relief to protect the buzzer.

[0023] As a preference of the present invention, the drainage device further includes a freewheeling diode connected in parallel with the water pump, and the freewheeling diode is used to counteract the back electromotive force and protect the water pump.

[0024] On the other hand, the present invention also provides a method for managing the liquid level in a cabin, characterized in that the method includes: S01. Install an external housing at the detection position on the outer wall of the cabin to be measured, and obtain the liquid level signal through multiple capacitive liquid level sensors arranged on the detection PCB board fixed in the external housing; S02. The capacitive liquid level sensor sends the liquid level signal to the liquid level detection circuit for signal preprocessing, and the liquid level detection circuit sends the liquid level signal to the central control unit; S03. The central control unit divides the detection gears according to the arrangement height of the capacitive liquid level sensor corresponding to the liquid level signal and the duration of the input of the liquid level signal, and generates management action commands under different detection gears; S04. The central control unit issues the management action command to the execution unit, and the execution unit performs water level management according to the management action command.

[0025] As a preference of the present invention, the management action command includes a type sub-command and a time sub-command, and the execution unit synchronously executes the type sub-command and the time sub-command.

[0026] In summary, the present invention has the following beneficial effects: 1. Through the integrated arrangement of the capacitive liquid level sensor, the liquid level detection circuit and the central control unit on the detection PCB board, and the application of the capacitive liquid level sensor with the ability to sense across the bulkhead, the present invention can achieve mechanical structure-free detection; and the overall circuit hardware structure is integrated in the external housing, which not only does not occupy the space inside the cabin to be measured, but also has a very small occupancy rate of the space outside the cabin to be measured.

[0027] 2. Based on the circuit pin arrangement of the single-chip microcomputer applied by the central control unit and the judgment of the preset program, and by means of the measurement of the time duration value by the built-in timer of the chip, the present detection system can distinguish whether the liquid level height corresponding to the received liquid level signal is the real liquid level height or the false height caused by the liquid surface fluctuation. With the operation of discarding the latter signal, the scientific rationality of the management action command issued by the central control unit is ensured, and the practical application value of the present system is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is the structural block diagram of the liquid level management system of this cabin; Figure 2 is the schematic diagram of the liquid level detection circuit in the embodiment; Figure 3 is the schematic diagram of the four operational amplifier circuits of the voltage follower circuit in the embodiment; Figure 4 is the schematic diagram of the circuit of the central control unit in the embodiment; Figure 5 is the schematic diagram of the circuit of the sound reminder device in the embodiment; Figure 6Schematic circuit diagram of the drainage device in the embodiment; Figure 7 Flowchart of the cabin liquid level management method. Detailed implementation manners

[0029] The preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Anyone can implement the present disclosure in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure will be more thorough and complete, and can fully convey the scope of the present disclosure to those skilled in the art.

[0030] As used herein, the term "including" and its variations mean open inclusion, that is, "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment".

[0031] As Figure 1 shown, the detection PCB board is installed in the external housing, and the external housing is installed on the outer wall of the measured cabin, closely attached to the outer wall of the measured cabin, and does not contact the water body in the measured cabin. Four capacitive liquid level sensors for obtaining liquid level signals are arranged on the detection PCB board. The capacitive liquid level sensors can detect whether the liquid level in the cabin reaches its own installation height through a medium (non-metallic medium). The capacitive liquid level sensors can be exposed on the detection PCB board through the windowing process (without applying green oil), and then fit with the non-metallic induction areas reserved on the outer wall of the measured cabin. Each window position on the detection PCB board is correspondingly provided with a capacitive liquid level sensor, and the window positions are arranged at intervals in the vertical height direction, that is, the four capacitive liquid level sensors are vertically spaced. When the capacitive liquid level sensors at different heights detect that there is liquid on the cabin wall, a liquid level signal is sent to the liquid level detection circuit electrically connected thereto.

[0032] As Figure 2As shown, the liquid level detection circuit is composed of a liquid level detection chip U2 and an auxiliary circuit. It integrates four liquid level detection channels, corresponding to four capacitive liquid level sensors respectively. Among them, C6 is a power supply filter capacitor; C7 is a reference capacitor for liquid level detection; R6 is a pull-down resistor; R7, R8, R9, and R10 are anti-interference resistors for liquid level detection; R11 and R12 are pull-down resistors; R13 and R14 are set resistors for liquid level detection sensitivity. By adjusting the resistance values of R13 and R14, the sensitivity of the liquid level detection chip U2 to the signals transmitted by the four capacitive liquid level sensors can be adjusted. The four input pins of the liquid level detection chip U2 correspond to CH1 to CH4, and are respectively connected to four capacitive liquid level sensors m1~m4 arranged at different height positions. When the capacitive liquid level sensors send out liquid level signals, the four-channel liquid level detection chip U2 transmits the signals to the voltage follower circuit through OUT1 to OUT4 respectively.

[0033] The voltage follower circuit serves as an isolation buffer stage. Its function is to provide a circuit interface with a high input impedance and a low output impedance, thereby reducing the impact interference of the central control unit on the aforementioned capacitive liquid level sensors and improving the judgment accuracy of the central control unit. As Figure 3 shown, the voltage follower circuit includes four operational amplifiers U3A, U4A, U5A, and U6A. Their respective input terminals (pin 3) are respectively connected to the OUT1, OUT2, OUT3, and OUT4 terminals of the four-channel liquid level detection chip U2. The inverting terminal (pin 2) and the output terminal (pin 1) of each operational amplifier are directly connected to convert the input voltage into an output voltage signal with a low output impedance and the same amplitude and frequency. The output terminals CH1_OUT1, CH2_OUT2, CH3_OUT3, and CH4_OUT4 of each operational amplifier are respectively connected to PA9, PB1, PB2, and PB3 of the single-chip microcomputer U1.

[0034] After the liquid level detection circuit sends the liquid level signal to the voltage follower circuit, it is output to the central control unit via the corresponding operational amplifier. The central control unit mainly consists of Figure 4It consists of the single-chip microcomputer U1 shown, where C5 is a power supply filtering capacitor. When the single-chip microcomputer U1 receives the corresponding voltage signal, it will judge whether the liquid level signal is valid based on the program burned into itself. Specifically, the single-chip microcomputer U1 will time the duration of this signal according to the built-in timer in itself, and obtain the voltage duration when the input pin receives this liquid level signal. After obtaining the duration, it will compare this duration with the set threshold time length of the capacitive liquid level sensor corresponding to this pin according to the automatic program. If this duration is greater than or equal to the set threshold time of the capacitive liquid level sensor corresponding to this pin, it means that the liquid level has indeed reached the installation height of this capacitive liquid level sensor, rather than accidentally reaching due to the liquid surface shaking. At this time, the central control unit judges that this liquid level signal is valid, and then the single-chip microcomputer U1 generates a warning action command to direct the subsequent warning behavior; if the time comparison fails, the central control unit judges that this liquid level signal is invalid. This liquid level signal is triggered due to the liquid surface shaking, and the actual liquid level height has not reached the installation height of this capacitive liquid level sensor, then the single-chip microcomputer U1 will not generate a warning action command and enter the silent state, waiting for the arrival of the liquid level signal at the next moment. In this embodiment, pins 9 to 12 of the single-chip microcomputer U1 are connected to the output ends of four operational amplifiers, its pin 1 is connected to the sound reminder device in the execution unit, and its pin 2 is connected to the drainage device in the execution unit.

[0035] In this embodiment, the execution unit includes a sound reminder device and a drainage device. As Figure 5 shown, where the sound reminder device includes a buzzer H1 that can emit a reminder sound after being powered on, and a first switch circuit for controlling the on / off of the buzzer H1. The first switch circuit is mainly composed of a switching transistor Q1. The voltage input terminal BUZZER for controlling the on / off of the switching transistor Q1 is connected to the output terminal pin 1 of the single-chip microcomputer U1. Figure 5 Among them, R2 is a base current limiting resistor; R4 is a pull-down resistor; C3 is a filtering capacitor; C2 is a power supply filtering capacitor; in addition, the sound reminder device also includes a discharge resistor R1 connected in parallel with the buzzer H1, and the discharge resistor R1 is used to release pressure to protect the buzzer H1. When the single-chip microcomputer U1 outputs a continuous high-level voltage signal to the switching transistor Q1, the switching transistor Q1 conducts, enabling the buzzer H1 to be powered on and continuously emit sound.

[0036] As shown in the figure, the drainage device includes a water pump J1 that can drive the execution of the pumping action by the motor after being powered on and a second switch circuit connected to the water pump J1 for controlling the on / off of the water pump J1. The second switch circuit is composed of a switching transistor Q2. Figure 6Among them, R3 is the base limit current resistor; R5 is the pull-down resistor; C4 is the filter capacitor; the drainage device further includes a freewheeling diode D1 connected in parallel with the water pump J1, and the freewheeling diode D1 is used to cancel the back electromotive force and protect the water pump (the water pump J1 is an inductive component. When the working state of the water pump J1 changes from conduction to cutoff, the water pump J1 will generate a back electromotive force, and D1 can provide a freewheeling path).

[0037] On the other hand, as Figure 7 shown, the present invention also provides a method for managing the liquid level in a cabin, and the method includes: S01. Install an external housing at the detection position on the outer wall of the measured cabin, and obtain liquid level signals by a plurality of capacitive liquid level sensors arranged on the detection PCB board fixed in the external housing; S02. The capacitive liquid level sensor sends the liquid level signal to the liquid level detection circuit for signal preprocessing, and the liquid level detection circuit sends the liquid level signal to the central control unit; S03. The central control unit divides the detection gears according to the arrangement height of the capacitive liquid level sensor corresponding to the liquid level signal and the duration of the liquid level signal input, and generates management action commands under different detection gears; S04. The central control unit sends the management action command to the execution unit, and the execution unit performs water level management according to the management action command.

[0038] Thus, taking four detection gears as an example, four capacitive liquid level sensors m1~m4 are arranged on the detection PCB board from low to high in the height direction, and are fixedly installed with the reserved non-metallic induction area on the outer wall of the measured cabin by means of the installation and fixing effect of the external housing.

[0039] When the water level in the measured cabin is at the normal liquid level (i.e., below the detection level P1 of the first stage), the capacitive liquid level sensor m1 arranged at the lowest height will not obtain a liquid level signal. At this time, both the central control unit and the execution unit are in the standby state; when the liquid level rises (it may be a real rise in the liquid level or a liquid level fluctuation caused by the hull swing), the capacitive liquid level sensor m1 arranged at the lowest height obtains a liquid level signal, and the liquid level detection circuit sends this signal to the central control unit. The central control unit receives this liquid level signal and uses the timing function of the single-chip microcomputer U1 to measure the time and obtain the value of the duration. When this value meets the preset length requirement, the above liquid level signal is considered valid. At this time, the central control unit, according to the pre-programmed program, divides the detection level based on this liquid level signal and the value of the signal duration (i.e., the detection level P1 of the first stage), and generates management action commands for different detection levels; when the detection level P1 of the first stage is divided, it can be known that the liquid level has only risen slightly at this time (and it is a real rise, because the triggering duration of the liquid level fluctuation caused by the hull swing for the capacitive liquid level sensor m1 is also fluctuating, not continuous. The successful acquisition of the detection level indicates that the duration of the signal has reached the preset duration value, which excludes the interference of false judgment of the liquid level fluctuation), and the management action command is generated for the detection level P1 of the first stage and sent to the execution unit. The management action command includes a type sub-command and a time sub-command, and the execution unit synchronously executes the type sub-command and the time sub-command.

[0040] Specifically, for example, in the management action command issued by the single-chip microcomputer U1 for the sound reminder device, based on the detection level P1 of the first stage, the type sub-command is to turn on the buzzer H1, and the time sub-command is to last for 10 seconds; in the management action command issued for the drainage device, based on the detection level P1 of the first stage, the type sub-command is to turn on the water pump J1, and the time sub-command is to last for 20 seconds.

[0041] If the capacitive liquid level sensors m2, m3 or m4 are triggered successively in reality, the detection level division will be correspondingly divided into the detection level P2 of the second stage, the detection level P3 of the third stage and the detection level P4 of the fourth stage, and the time lengths under their respective time sub-commands will increase successively so that the "intensity" of the action execution of the execution unit can meet the alarm and drainage requirements of the current liquid level situation.

[0042] Multiple embodiments of the present disclosure have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other ordinary technicians in the technical field to understand the disclosed embodiments.

Claims

1. A tank liquid level management system, comprising an external housing, characterized in that: It also includes a detection PCB board installed in the external housing, wherein a plurality of capacitive liquid level sensors for obtaining liquid level signals are arranged on the detection PCB board, and the plurality of capacitive liquid level sensors are arranged vertically and spaced apart; The detection system also includes a liquid level detection circuit arranged on the detection PCB board and connected to the capacitive liquid level sensor, and a central control unit connected to the liquid level detection circuit; the central control unit receives the liquid level signal, and automatically obtains the duration of the liquid level signal, and determines whether the corresponding liquid level signal is valid based on the duration, and generates a management action command if it is valid, and waits for the liquid level signal at the next moment if it is invalid.

2. A tank liquid level management system according to claim 1, characterized in that: A voltage follower circuit for isolation and buffering is also provided between the liquid level detection circuit and the central control unit, and the voltage follower circuit includes a plurality of operational amplifiers.

3. A tank liquid level management system according to claim 1, characterized in that: The cabin liquid level management system also includes an action unit connected to the central control unit, and the action unit includes a sound reminder device, a light reminder device and a drainage device.

4. A tank liquid level management system according to claim 3, characterized in that: The sound reminder device includes a buzzer and a first switch circuit connected to the buzzer and used for controlling the buzzer to be turned on / off.

5. A tank liquid level management system according to claim 3, characterized in that: The drainage device includes a water pump and a second switch circuit connected to the water pump and used for controlling the water pump to be turned on / off.

6. A tank liquid level management system according to claim 2, characterized in that: The central control unit includes a single-chip microcomputer U1 and a filter capacitor connected to the single-chip microcomputer U1; the single-chip microcomputer U1 has a built-in timer, and the timer is used to automatically calculate the duration of the input pin receiving the voltage signal.

7. A tank liquid level management system according to claim 4, characterized in that: The sound reminder device further includes a discharge resistor connected in parallel with the buzzer, and the discharge resistor is used for pressure relief to protect the buzzer.

8. A tank liquid level management system according to claim 5, characterized in that: The drainage device also includes a freewheeling diode connected in parallel with the water pump, and the freewheeling diode is used to offset the reverse electromotive force and protect the water pump.

9. A method for managing liquid level in a ship's hold, characterized in that: Methods include: S01, installing an external housing at a detection position of the outer wall of the tested cabin, and obtaining a liquid level signal from a plurality of capacitive liquid level sensors arranged on a detection PCB board fixed in the external housing; S02, the capacitive liquid level sensor sends the liquid level signal to the liquid level detection circuit for signal preprocessing, and the liquid level detection circuit sends the liquid level signal to the central control unit; S03, the central control unit divides the detection gear according to the arrangement height of the capacitive liquid level sensor corresponding to the liquid level signal and the duration of the liquid level signal input, and generates management action commands under different detection gears; S04: The central control unit sends the management action command to the action unit, and the action unit performs water level management according to the management action command.

10. A method for managing liquid level in a ship tank according to claim 9, characterized in that: The management action command includes a type subcommand and a time subcommand, and the action unit executes the type subcommand and the time subcommand synchronously.

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