A liquid level detection device based on magnetic sensor

Abstract

The application provides a liquid level detection device based on a magnetic sensor, comprising at least three magnetic sensors, each of which is provided with an enable port for receiving a synchronization signal, a synchronization signal sending port, and an output port for outputting a magnetic field detection result; all the magnetic sensors are connected in sequence to form a daisy chain topology, and the enable ports of the magnetic sensors except the head magnetic sensor are connected with the synchronization signal sending ports of the previous stage magnetic sensors; each magnetic sensor realizes the verification of the synchronization signal and judges whether the magnetic sensor is the head magnetic sensor by identifying different identification marks of the synchronization signal, and performs the state control of the magnetic sensor and the sending of the synchronization signal according to the judgment result, so as to realize the sequential working and sleeping of each magnetic sensor. The liquid level detection device of the application realizes the verification of the synchronization signal and guarantees the timing accuracy through the synchronization signal verification mechanism, and realizes the high-precision system response under the condition of low power consumption.

Description

Technical Field

[0001] This invention relates to the field of liquid level detection technology, and more specifically to a liquid level detection device based on a magnetic sensor. Background Technology

[0002] In the prior art, patent CN221630841U, entitled "A Liquid Level Detection Device Based on a Magnetic Sensor," proposes a liquid level detection device based on a daisy-chain topology for measuring the liquid level height of liquid containers (such as storage tanks and reaction vessels). The container needs to be equipped with a magnetic float, which moves up and down with the liquid level. Changes in the magnetic field trigger the response of the magnetic sensor. This liquid level detection device achieves time-sharing start-up control through series magnetic sensors, reducing system power consumption.

[0003] However, the following technical bottlenecks exist in this scheme: (1) When multiple modules transmit synchronous signals, the lack of a verification mechanism leads to timing inaccuracies, affecting measurement accuracy; (2) Under a single signal transmission path, if any normally connected module fails, the link will be interrupted and cannot be automatically recovered, affecting the reliability of the system. Based on the daisy-chain topology structure inherited from CN221630841U, this invention proposes a dynamic synchronous verification and multi-path fault tolerance mechanism integrated into the magnetic sensor. Through synchronous signal verification and redundant signal fault tolerance functions, the reliability of the liquid level detection system is improved.

[0004] Therefore, it is urgent to design a system that can accurately verify the synchronization signal and automatically recover from link failures, based on the low power consumption advantage of existing daisy-chain topology-based liquid level detection devices, in order to solve the problems of timing inaccuracies and easy link interruptions in existing devices. Summary of the Invention

[0005] The purpose of this invention is to provide a liquid level detection device based on a magnetic sensor, so as to realize the verification of the synchronization signal and ensure the timing accuracy, and still work normally when the connection is abnormal, thereby improving the accuracy of liquid level detection and system reliability.

[0006] To achieve the above objectives, the present invention provides a liquid level detection device based on magnetic sensors, comprising at least three magnetic sensors. Each magnetic sensor has an enable port for receiving a synchronization signal, a synchronization signal transmission port, and an output port for outputting magnetic field detection results. All magnetic sensors are connected in sequence to form a daisy-chain topology. Except for the head magnetic sensor, the enable ports of the other magnetic sensors are connected to the synchronization signal transmission port of the previous level magnetic sensor. Each magnetic sensor verifies and determines whether it is the head magnetic sensor by identifying different identification marks of the synchronization signal, and performs state control of the magnetic sensor and transmission of the synchronization signal based on the determination result, thereby enabling each magnetic sensor to work and sleep in sequence.

[0007] The synchronization signal includes multiple identification markers, including at least a head magnetic sensor identification marker and a wake-up identification marker, and each identification marker has a distinguishable signal form;

[0008] Each magnetic sensor is configured as follows:

[0009] When the head magnetic sensor identification mark is detected, it is determined to be a head magnetic sensor and enters a work-sleep cycle self-loop, which periodically enters the working state, detects the magnetic field and outputs the detection result, sends a wake-up identification mark to the next level magnetic sensor, and enters the sleep state.

[0010] When the wake-up identification flag is detected, it is determined to be a non-head magnetic sensor and enters the working state, detects the magnetic field and outputs the detection result, sends the wake-up identification flag to the next level magnetic sensor, and enters the sleep state.

[0011] The identification flag for the head magnetic sensor is either the floating state of the enable port of the head magnetic sensor or an external signal connected to the enable port of the head magnetic sensor.

[0012] The identification mark also includes a connection identification mark and a handshake identification mark;

[0013] Each magnetic sensor is configured as follows:

[0014] When the connection identification mark is detected, it is determined that the current magnetic sensor is in the position of the non-head magnetic sensor, and it remains in sleep mode and waits for the synchronization signal;

[0015] A handshake identification flag is sent to the next level magnetic sensor at fixed time intervals; when the handshake identification flag is detected, the current magnetic sensor is determined to be in the position of a non-head magnetic sensor, and remains in sleep mode while waiting for the synchronization signal.

[0016] The transmission cycle of the handshake identification flag is shorter than that of the wake-up identification flag.

[0017] When an abnormal connection occurs in the daisy-chain topology, each magnetic sensor identifies the synchronization signal to determine whether it should become the new head magnetic sensor. When it becomes the new head magnetic sensor, it enters a work-sleep cycle self-loop, thereby realizing the fault tolerance mechanism of the liquid level detection function. The abnormal connection includes any magnetic sensor being damaged, any pin of any magnetic sensor being short-circuited, disconnected, or malfunctioning.

[0018] The identification markers for the synchronization signal include a head magnetic sensor identification marker and a handshake identification marker;

[0019] Each sensor is configured as follows:

[0020] When the enable port is disconnected from the synchronization signal transmission port of the previous magnetic sensor, and the head magnetic sensor identification mark is detected, it is determined to be a new head magnetic sensor and enters the work-sleep cycle self-loop.

[0021] A handshake identification flag is sent to the next level magnetic sensor at fixed time intervals; if no handshake identification flag is received after waiting for a preset handshake duration, it is determined to be a new head magnetic sensor and enters a work-sleep cycle self-loop.

[0022] Each magnetic sensor integrates a magnetic switch assembly and a synchronization signal verification and fault tolerance system.

[0023] The synchronization signal verification and fault-tolerant system includes an oscillator, a synchronization enable control module, a synchronization signal transmission module, and a timing state control module. The oscillator autonomously outputs a clock signal. The synchronization enable control module outputs operating and sleep control signals for the magnetic sensor based on the clock signal and the synchronization signal. The timing state control module outputs a timing state control signal to the magnetic switch assembly based on the clock signal and the operating and sleep control signals, causing the magnetic sensor to switch between operating and sleep states. The synchronization signal transmission module transmits a synchronization signal through the synchronization signal transmission port based on the clock signal and the operating and sleep control signals.

[0024] The magnetic switch assembly includes a Hall sensor, a Hall signal processing module, and an output module connected in sequence.

[0025] This invention proposes a liquid level detection device based on magnetic sensors, building upon existing daisy-chain topologies. It integrates a synchronization signal verification mechanism and a fault-tolerance mechanism. The synchronization signal verification mechanism verifies the synchronization signal and ensures timing accuracy, enabling each sensor in the daisy-chain topology to operate sequentially and achieving high-precision system response with low power consumption. The fault-tolerance system ensures that even if any normally connected magnetic sensor fails or any magnetic sensor port connection is abnormal, the liquid level detection device maintains the integrity of the daisy chain and continues to operate normally, thereby improving the accuracy of liquid level detection and the reliability of the system. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the liquid level detection device based on a magnetic sensor according to the present invention;

[0027] Figure 2 This is an example diagram of the various identification markers for the synchronization signal.

[0028] Figure 3 This is an internal framework diagram of a magnetic sensor that integrates a synchronization signal verification and fault-tolerant system. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0030] like Figure 1 The image shows a liquid level detection device based on a magnetic sensor according to an embodiment of the present invention, which is an improvement upon the liquid level detection device described in patent document CN221630841U. For example... Figure 1 As shown, the liquid level detection device includes at least three magnetic sensors, each with five ports: a power port (VDD), a ground port (GND), an enable port (EN), a synchronization signal transmission port (HC), and an output port (OUT). The enable port (EN) receives the synchronization signal, the synchronization signal transmission port (HC) transmits the synchronization signal, and the output port (OUT) outputs the magnetic field detection result. The power port (VDD) is used to connect to a power source, and the ground port (GND) is used for grounding.

[0031] All magnetic sensors are connected sequentially to form a daisy-chain topology. Except for the head magnetic sensor, the enable port EN of all other magnetic sensors is connected to the synchronization signal transmission port HC of the preceding magnetic sensor. This allows control over the startup time of each magnetic sensor. In this embodiment, the enable port EN of the head magnetic sensor is left floating, and the synchronization signal transmission port HC of the tail magnetic sensor is also left floating. In other embodiments, the enable port EN of the head magnetic sensor can be connected to an external signal, such as a continuous low or high level. Alternatively, the enable port EN of any magnetic sensor can be connected to an external signal as needed to distinguish which sensor is the head magnetic sensor.

[0032] Each magnetic sensor verifies the synchronization signal and determines whether it is a head magnetic sensor by identifying different identification marks of the synchronization signal. Based on the judgment result, it controls the state of the magnetic sensor and sends the synchronization signal, so that each magnetic sensor works and goes into sleep mode in sequence, thus realizing the synchronization signal verification mechanism. There are various synchronization signal verification mechanisms, and this patent only exemplifies a few forms. Other forms of synchronization signal detection mechanisms are also included.

[0033] In this embodiment, the synchronization signal includes four types of identification markers: a head magnetic sensor identification marker, a wake-up identification marker, a connection identification marker, and a handshake identification marker. Each identification marker has a distinguishable signal form. The number of identification markers is not fixed at four; it can be designed according to requirements. For example, the connection identification marker and the handshake identification marker can be omitted if it is not necessary to detect abnormalities. However, the synchronization signal typically includes at least the head magnetic sensor identification marker and the wake-up identification marker.

[0034] In this embodiment, the enable port EN of the head magnetic sensor is left floating, and the head magnetic sensor identification mark is the floating state of the enable port EN of the head magnetic sensor (the floating state can be processed into the head magnetic sensor identification mark through internal digital logic).

[0035] In other embodiments, the identification markers can take any form, as long as they are distinguishable from each other. The head magnetic sensor can be connected to an external signal, and the head magnetic sensor identification marker can also be set as an external signal connected to the enable port EN of the head magnetic sensor, such as a continuously low level or a continuously high level (e.g., power supply voltage), serving as a fixed head magnetic sensor identification marker. For example, as... Figure 2 As shown, in Example 1, the head magnetic sensor identification flag is a continuous low level, the connection identification flag is a continuous high level, the wake-up identification flag is a square wave of a fixed duration and frequency, and the handshake identification flag is a short-duration low level; in Example 2, the head magnetic sensor identification flag is a continuous high level, the connection identification flag is a continuous low level, the wake-up identification flag is a high level of a long time threshold, and the handshake identification flag is a high level of a short time threshold.

[0036] In this embodiment, in order to verify the synchronization signal and determine whether the magnetic sensor is a head magnetic sensor, and to control the state of the magnetic sensor and send the synchronization signal based on the determination result, each magnetic sensor is configured to perform the following steps:

[0037] 1) When the head magnetic sensor identification mark is detected, the current magnetic sensor is determined to be a head magnetic sensor. It immediately enters the work-sleep cycle self-loop, periodically entering the working state, detecting the magnetic field and outputting the detection result, sending the wake-up identification mark to the next level magnetic sensor, and entering the sleep state.

[0038] 2) When the wake-up recognition flag is detected, the current magnetic sensor is determined to be in the position of a non-head magnetic sensor, and immediately enters the working state, detects the magnetic field and outputs the detection result, sends the wake-up recognition flag to the next level magnetic sensor, and enters the sleep state.

[0039] 3) When the connection identification flag is detected, it is determined that the current magnetic sensor is in the position of the non-head magnetic sensor, and it remains in sleep state and waits for the synchronization signal; wherein, the connection identification flag is provided by the synchronization signal transmission port HC of the previous magnetic sensor. Since the non-head magnetic sensor connects the synchronization signal transmission port HC of the previous magnetic sensor and the enable port EN of the current magnetic sensor through a lead, the non-head magnetic sensor can receive the connection identification flag.

[0040] 4) Send a handshake identification flag to the next level magnetic sensor at fixed time intervals; when the handshake identification flag is detected, determine that the current magnetic sensor is in the position of a non-head magnetic sensor, keep in sleep state and continue to wait for the synchronization signal.

[0041] The transmission period of the handshake identification flag is shorter than that of the wake-up identification flag. This prevents the non-head magnetic sensor from switching to the head magnetic sensor and entering a work-sleep cycle due to not receiving a handshake signal within a wake-up cycle. If the transmission period of the handshake identification flag is longer than the wake-up cycle, the non-head sensor may operate before receiving the previous wake-up signal because it has not received the handshake identification flag, causing timing disorder. Preferably, the transmission period of the wake-up identification flag is more than twice that of the handshake identification flag to prevent the sensor from operating prematurely due to an unexpected failure to recognize a handshake signal.

[0042] like Figure 3 As shown, the working principle of the liquid level detection device based on magnetic sensors is as follows: When the liquid level detection device is normally connected, it is powered on. The head magnetic sensor (i.e., the first magnetic sensor N1 in the daisy-chain topology) detects the head magnetic sensor identification flag and immediately enters a work-sleep cycle (i.e., periodically enters the working state, detects the magnetic field and outputs the detection result, sends a wake-up identification flag to the next-level magnetic sensor, and enters the sleep state). After being powered on, the next-level magnetic sensor (i.e., the second magnetic sensor N2 in the daisy-chain topology) receives the wake-up identification flag from the previous-level magnetic sensor (i.e., the first magnetic sensor N1 in the daisy-chain topology), enters the working state, detects the ambient magnetic field and outputs it, sends a wake-up identification flag to the next-level magnetic sensor (i.e., the third magnetic sensor N3 in the daisy-chain topology), and then enters the sleep state. The operation of subsequent magnetic sensors is consistent with that of the second magnetic sensor N2. Each magnetic sensor in a properly connected system enters working mode upon receiving a wake-up identification flag from the previous level magnetic sensor. It detects and outputs the ambient magnetic field, sends a wake-up identification flag to the next level magnetic sensor, and then enters sleep mode. Furthermore, each magnetic sensor periodically sends a handshake identification flag to the next level magnetic sensor. Each magnetic sensor other than the head magnetic sensor remains in sleep mode when it detects a connection identification flag. If a magnetic sensor does not receive a handshake identification flag for a certain period, it will automatically initiate a work-sleep cycle and become the new head magnetic sensor. Thus, the daisy-chain topology of the liquid level detection device enables sequential operation and sleep of each magnetic sensor from start to finish. Under normal circumstances, only one magnetic sensor is active at a time, reducing system power consumption while ensuring system responsiveness.

[0043] During the liquid level detection cycle, when any magnetic sensor detects the float approaching within the working time, its output port OUT outputs the float's position level (e.g., ground level). The voltage at the output port OUT of the magnetic sensor is detected by the output signal detection module, and the liquid level can be determined based on this voltage. In this embodiment, the output signal detection module detects the voltage at the output port OUT of the head magnetic sensor. Each magnetic sensor's output port OUT is connected to the output port OUT of the next-level magnetic sensor via a resistor, and the output port OUT of the tail magnetic sensor is grounded via a resistor. A current source is connected to the output port OUT of the head magnetic sensor. Accordingly, the principle of determining the liquid level based on the voltage value detected by the voltage detection module is as follows: the current value IR of the current source is known, and VQ is the detected voltage value. Since the float's level is detected to be pulled down to ground level, the resistance between the grounding point and the current source can be calculated using VQ / IR = R. The total resistance of the grounding resistor is determined based on this resistance, which in turn determines the ordinal number of the magnetic sensor whose output port OUT is grounded. The location of the Hall element of the magnetic sensor whose output port OUT is grounded indicates the liquid level. In other embodiments, the positions of the output signal detection module, current source, and resistor can be configured as needed, as long as the output signal detection module detects the voltage at the output port OUT of the magnetic sensor and can determine the liquid level based on the voltage at the output port OUT of the magnetic sensor. For example, the output port OUT of each magnetic sensor can be directly grounded through a resistor, the resistance value of each magnetic sensor can be different, and the current source and output signal detection module can be connected to the output ports OUT of all magnetic sensors.

[0044] Furthermore, in the event of an abnormal connection in the daisy-chain topology, each magnetic sensor identifies a synchronization signal to determine whether it should become the new head magnetic sensor. Upon becoming the new head magnetic sensor, it enters a self-circulating work-sleep cycle, periodically entering working mode, detecting the magnetic field and outputting the detection result, sending a wake-up identification flag to the next-level magnetic sensor, and then entering sleep mode. This achieves a fault-tolerant mechanism for the liquid level detection function. In other words, it enables automatic recovery of the liquid level detection function in the event of an anomaly, thus realizing the fault-tolerant mechanism of the liquid level detection system.

[0045] Abnormal connection situations include, but are not limited to, damage to any magnetic sensor, or short circuit, disconnection, or malfunction of any pin of any magnetic sensor.

[0046] In order to automatically restore the liquid level detection function in the event of an abnormal connection, each magnetic sensor is configured as follows:

[0047] 1) When the enable port EN is disconnected from the synchronization signal transmission port HC of the previous magnetic sensor, resulting in the detection of the head magnetic sensor identification flag, the current magnetic sensor is determined to become the new head magnetic sensor, and immediately enters the work-sleep cycle self-loop, so as to periodically enter the working state, detect the magnetic field and output the detection result, send the wake-up identification flag to the next level magnetic sensor, and enter the sleep state.

[0048] 2) Send a handshake identification flag to the next level magnetic sensor at fixed time intervals; when the enable port EN is connected to the synchronization signal transmission port HC of the previous level magnetic sensor, but an abnormal connection causes the synchronization signal of the synchronization signal transmission port HC to fail to be sent normally, resulting in no handshake identification flag being received after waiting for the preset handshake time, the current magnetic sensor is determined to become the new head magnetic sensor, and immediately enters the work-sleep cycle self-loop, periodically entering the working state, detecting the magnetic field and outputting the detection result, sending a wake-up identification flag to the next level magnetic sensor, and entering the sleep state.

[0049] Once any magnetic sensor becomes the new head magnetic sensor, the subsequent cascaded magnetic sensors still follow the synchronization signal verification rules described above, receive the wake-up identification flag in sequence, and complete the work-sleep switch to maintain the complete operation of the entire daisy chain.

[0050] Based on the fault tolerance mechanism described above, two common exceptions are introduced below:

[0051] Abnormal Condition 1: The enable port EN of the non-head magnetic sensor is disconnected from the synchronization signal transmission port HC of the previous stage. Figure 3 Taking the second magnetic sensor N2 as an example, when the liquid level detection device is working normally, the enable port EN of the second magnetic sensor N2 is suddenly disconnected from the synchronization signal transmission port HC of the first magnetic sensor N1. Under the fault-tolerant mechanism, the second magnetic sensor N2 will become the first magnetic sensor and immediately enter the working state, detect the ambient magnetic field and output it, and at the same time start the working-sleep cycle self-loop, sending a wake-up identification flag to the next level magnetic sensor to maintain the normal response of all magnetic sensors.

[0052] Abnormal Case 2: The enable port EN of the non-head magnetic sensor remains connected to the synchronization signal transmission port HC of the previous-level magnetic sensor, but its function is malfunctioning. (The rest of the text appears to be a separate, unrelated statement.) Figure 3Taking the second magnetic sensor N2 as an example, when the liquid level detection device is working normally, the synchronization signal transmission port HC of the first magnetic sensor N1 malfunctions. It maintains a normal connection but cannot send a signal to the second magnetic sensor N2. Under the action of the fault-tolerant system, the second magnetic sensor N2 enters the working state after waiting for a certain period of time, detects the ambient magnetic field and outputs it, starts the working-sleep cycle self-loop, and sends a wake-up identification flag to the next level magnetic sensor to maintain the normal response of all magnetic sensors.

[0053] like Figure 1 As shown, the magnetic sensor integrates a magnetic switch assembly and a synchronization signal verification and fault tolerance system.

[0054] The magnetic switch assembly is configured to detect the magnetic field and output the detection result when the magnetic sensor is in operation. Specifically, when a float is detected, the output port OUT outputs the float's position level. When the magnetic sensor is in sleep mode, it is turned off and does not detect the magnetic field to reduce power consumption. The magnetic switch assembly includes a Hall sensor 11, a Hall signal processing module 12, and an output module 13 connected in sequence.

[0055] The Hall signal processing module 12 has a built-in comparator that converts the magnetic signal sensed by the Hall sensor 11 into a magnetic induction voltage and compares it with an internal threshold voltage. The comparison result is output to the output module 13. The output module 13 is used to output a high / low level magnetic field detection result based on the comparison result. It adopts a traditional output structure, including one of the following: a built-in pull-up / pull-down resistor output structure, an external pull-up / pull-down resistor output structure, or a CMOS push-pull output structure.

[0056] The synchronization signal verification and fault tolerance system 20 is configured to implement a synchronization signal verification mechanism and a fault tolerance mechanism. Specifically, it is configured to: verify the synchronization signal and determine whether the magnetic sensor is a head magnetic sensor by identifying different identification flags of the synchronization signal; and control the state of the magnetic sensor and send the synchronization signal based on the determination result, thus implementing the synchronization signal verification mechanism; and in the event of an abnormal connection, identify the synchronization signal to determine whether the magnetic sensor has become a new head magnetic sensor. When it becomes a new head magnetic sensor, it enters a work-sleep cycle self-loop, periodically entering the working state, detecting the magnetic field and outputting the detection result, sending a wake-up identification flag to the next-level magnetic sensor, and entering the sleep state, thereby implementing a fault tolerance mechanism for the liquid level detection function.

[0057] The synchronization signal verification and fault tolerance system 20 includes an oscillator 21, a synchronization enable control module 22, a synchronization signal transmission module 23, and a timing status control module 24.

[0058] Among them, the oscillator 21 is configured to autonomously output a clock signal to provide a clock reference for the synchronization enable control module 22, the synchronization signal sending module 23, and the timing state control module 24.

[0059] The synchronization enable control module 21 receives and verifies the synchronization signal to determine whether the magnetic sensor is a head magnetic sensor, and controls the switching between the working and sleep states of the magnetic sensor based on the determination result. The inputs to the synchronization enable control module 21 are the synchronization signal from the enable port EN and the clock signal from the OSC oscillator. After internal digital logic processing, the module determines the position of the magnetic sensor (whether it is a head magnetic sensor) and outputs the working and sleep control signals for the magnetic sensor, thereby realizing the reception and verification of the synchronization signal.

[0060] The timing state control module 24 outputs a timing state control signal to the Hall signal processing module 12 of the magnetic switch assembly based on the clock signal and the working and sleep control signals of the magnetic sensor, so that the state of the magnetic sensor switches between the working state and the sleep state.

[0061] The synchronization signal sending module 23 sends a synchronization signal through the synchronization signal sending port HC based on the clock signal and the working and sleep control signals from the synchronization enable control module 21. The sent synchronization signal includes a wake-up identification flag and a handshake identification flag. When not sending a synchronization signal, the synchronization signal sending module 23 keeps the synchronization signal sending port HC in the state of the connection identification flag.

[0062] Traditional daisy-chain topology liquid level detection devices suffer from timing inaccuracies due to the lack of a synchronization signal verification mechanism, affecting measurement accuracy. Furthermore, these devices lack a fault-tolerant system; failure of any normally connected magnetic sensor or abnormal connection at any magnetic sensor port will cause a link interruption that cannot be automatically recovered, impacting system reliability. This invention proposes a magnetic sensor-based liquid level detection device based on the existing daisy-chain topology. This device integrates a synchronization signal verification mechanism and a fault-tolerant mechanism. The synchronization signal verification mechanism ensures that all sensors in the daisy-chain topology operate sequentially, achieving high-precision system response with low power consumption. The fault-tolerant system ensures that the liquid level detection device maintains the integrity of the daisy chain even in the event of failure of any normally connected magnetic sensor or abnormal connection at any magnetic sensor port, improving system reliability.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. Various variations can be made to the above embodiments of the present invention. All simple and equivalent changes and modifications made in accordance with the claims and description of this application fall within the protection scope of the claims of this patent. All aspects not described in detail in this invention are conventional technical content.

Claims

1. A liquid level detection device based on a magnetic sensor, characterized in that, It includes at least three magnetic sensors. Each magnetic sensor has an enable port for receiving synchronization signals, a synchronization signal transmission port, and an output port for outputting magnetic field detection results. All magnetic sensors are connected in sequence to form a daisy-chain topology. Except for the head magnetic sensor, the enable ports of the other magnetic sensors are connected to the synchronization signal transmission ports of the previous level magnetic sensor. Each magnetic sensor verifies and determines whether it is a head magnetic sensor by identifying different identification marks of the synchronization signal. Based on the determination result, it controls the state of the magnetic sensor and transmits the synchronization signal, thereby enabling each magnetic sensor to work and sleep in sequence.

2. The liquid level detection device based on a magnetic sensor according to claim 1, characterized in that, The synchronization signal includes multiple identification markers, including at least a head magnetic sensor identification marker and a wake-up identification marker, and each identification marker has a distinguishable signal form; Each magnetic sensor is configured as follows: When the head magnetic sensor identification mark is detected, it is determined to be a head magnetic sensor and enters a work-sleep cycle self-loop, which periodically enters the working state, detects the magnetic field and outputs the detection result, sends a wake-up identification mark to the next level magnetic sensor, and enters the sleep state. When the wake-up identification flag is detected, it is determined to be a non-head magnetic sensor and enters the working state, detects the magnetic field and outputs the detection result, sends the wake-up identification flag to the next level magnetic sensor, and enters the sleep state.

3. The liquid level detection device based on a magnetic sensor according to claim 2, characterized in that, The identification flag for the head magnetic sensor is either the floating state of the enable port of the head magnetic sensor or an external signal connected to the enable port of the head magnetic sensor.

4. The liquid level detection device based on a magnetic sensor according to claim 2, characterized in that, The identification mark also includes a connection identification mark and a handshake identification mark; Each magnetic sensor is configured as follows: When the connection identification mark is detected, it is determined that the current magnetic sensor is in the position of the non-head magnetic sensor, and it remains in sleep mode and waits for the synchronization signal; A handshake identification flag is sent to the next level magnetic sensor at fixed time intervals; when the handshake identification flag is detected, the current magnetic sensor is determined to be in the position of a non-head magnetic sensor, and remains in sleep mode while waiting for the synchronization signal.

5. The liquid level detection device based on a magnetic sensor according to claim 4, characterized in that, The transmission cycle of the handshake identification flag is shorter than that of the wake-up identification flag.

6. The liquid level detection device based on a magnetic sensor according to claim 1, characterized in that, When an abnormal connection occurs in the daisy-chain topology, each magnetic sensor identifies the synchronization signal to determine whether it should become the new head magnetic sensor. When it becomes the new head magnetic sensor, it enters a work-sleep cycle self-loop, thereby realizing the fault tolerance mechanism of the liquid level detection function. The abnormal connection includes any magnetic sensor being damaged, any pin of any magnetic sensor being short-circuited, disconnected, or malfunctioning.

7. The liquid level detection device based on a magnetic sensor according to claim 6, characterized in that, The identification markers for the synchronization signal include a head magnetic sensor identification marker and a handshake identification marker; Each sensor is configured as follows: When the enable port is disconnected from the synchronization signal transmission port of the previous magnetic sensor, and the head magnetic sensor identification mark is detected, it is determined to be a new head magnetic sensor and enters the work-sleep cycle self-loop. A handshake identification flag is sent to the next level magnetic sensor at fixed time intervals; if no handshake identification flag is received after waiting for a preset handshake duration, it is determined to be a new head magnetic sensor and enters a work-sleep cycle self-loop.

8. The liquid level detection device based on a magnetic sensor according to claim 1, characterized in that, Each magnetic sensor integrates a magnetic switch assembly and a synchronization signal verification and fault tolerance system.

9. The liquid level detection device based on a magnetic sensor according to claim 8, characterized in that, The synchronization signal verification and fault-tolerant system includes an oscillator, a synchronization enable control module, a synchronization signal transmission module, and a timing state control module. The oscillator autonomously outputs a clock signal. The synchronization enable control module outputs operating and sleep control signals for the magnetic sensor based on the clock signal and the synchronization signal. The timing state control module outputs a timing state control signal to the magnetic switch assembly based on the clock signal and the operating and sleep control signals, causing the magnetic sensor to switch between operating and sleep states. The synchronization signal transmission module transmits a synchronization signal through the synchronization signal transmission port based on the clock signal and the operating and sleep control signals.

10. The liquid level detection device based on a magnetic sensor according to claim 9, characterized in that, The magnetic switch assembly includes a Hall sensor, a Hall signal processing module, and an output module connected in sequence.

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