A monitoring device

Abstract

This application discloses a monitoring device comprising a passive sensor, an energy management unit, a communication unit, an electric field energy storage unit, and an event storage unit. The electric field energy storage unit supplies power to the passive sensor, the energy management unit, the communication unit, and the event storage unit. The energy management unit converts electromagnetic waves from the external environment into electrical energy and stores the electrical energy in the electric field energy storage unit. The passive sensor generates a sensing event upon detecting the presence of a target and stores the sensing event in the event storage unit. The communication unit transmits the sensing event from the event storage unit to the external reading device upon receiving a carrier wave from an external reading device. Thus, by combining the passive sensor, the electric field energy storage unit, and the communication unit, the power consumption, size, and cost of the monitoring device are reduced.

Description

Technical Field

[0001] This application relates to the field of monitoring technology, and more particularly to a monitoring device. Background Technology

[0002] In fields such as wildlife monitoring, hunting observation, and ecological surveys, long-term, continuous surveillance and data collection of target areas are typically required using monitoring equipment. Currently, hunting cameras are the most widely used monitoring equipment in these applications. A typical hunting camera integrates a passive infrared sensor, an imaging sensor, a night vision lighting component, a local storage module, a battery power system, and optional cellular network or short-range wireless communication modules. When operating, this type of monitoring equipment actively acquires image or video data through its imaging sensor and actively transmits the data via its wireless communication module, thereby achieving the monitoring and information transmission of targets in the wild.

[0003] However, because these hunting cameras rely on active imaging and active wireless data transmission, their overall power consumption is typically in the tens to hundreds of milliwatts. This high power consumption necessitates the use of large-capacity batteries and corresponding power management circuitry, resulting in a larger overall size and higher hardware costs for the monitoring equipment. Summary of the Invention

[0004] This application provides a monitoring device to solve the problems of high power consumption, large size, and high cost of existing monitoring devices.

[0005] This application provides a monitoring device, which includes a passive sensor, an energy management unit, a communication unit, an electric field energy storage unit, and an event storage unit. The electric field energy storage unit supplies power to the passive sensor, the energy management unit, the communication unit, and the event storage unit, respectively. The energy management unit is used to convert electromagnetic waves from the external environment of the monitoring device into electrical energy and store the electrical energy in the electric field energy storage unit. The passive sensor is used to generate a sensing event when it detects the presence of a target, and to store the sensing event in the event storage unit; The communication unit is configured to send the sensed event in the event storage unit to the external reading device upon receiving a carrier wave sent by the external reading device.

[0006] Optionally, the communication unit is further configured to, upon receiving a carrier wave sent by an external reading device, encode the sensing event in the event storage unit and the voltage of the electric field energy storage unit according to a target encoding method to obtain target encoding information, and send the target encoding information to the external reading device; wherein the target encoding method is determined based on the voltage of the electric field energy storage unit.

[0007] Optionally, when the voltage of the electric field energy storage unit is equal to or greater than the first voltage value, the target encoding method is the first encoding method; when the voltage of the electric field energy storage unit is equal to or greater than the second voltage value and less than the first voltage value, the target encoding method is the second encoding method; when the voltage of the electric field energy storage unit is less than the second voltage value, the sensing event is not sent; wherein, the communication rate of the second encoding method is less than the communication rate of the first encoding method.

[0008] Optionally, when the target encoding method is the first encoding method, the communication unit is further configured to determine the encoding rate in the first encoding method based on the voltage obtained by converting the signal strength of the carrier; and to encode the sensing event in the event storage unit and the voltage of the electric field energy storage unit using the first encoding method and the encoding rate to obtain target encoding information.

[0009] Optionally, the monitoring device further includes a control unit connected to the communication unit; the control unit is configured to connect the electric field energy storage unit and the communication unit upon receiving a carrier wave sent by the external reading device, so that the electric field energy storage unit supplies power to the communication unit.

[0010] Optionally, the control unit is also connected to the passive sensor; the passive sensor is further configured to generate a sensing event when a target is detected, and send the sensing event to the control unit; the control unit is further configured to increment the count result in the event counter in the event storage unit when the sensing event is received; the communication unit is further configured to send the count result of the event counter to the external reading device.

[0011] Optionally, the passive sensor is further configured to generate a differential-mode electrical signal based on the sensed signal, and determine the presence of a target if the differential-mode electrical signal meets preset conditions.

[0012] Optionally, the preset conditions include: the differential mode electrical signal is greater than a signal threshold within a preset number of consecutive time windows; wherein the preset number and the signal threshold are determined based on the temperature of the environment in which the monitoring device is located.

[0013] Optionally, the electromagnetic wave includes a carrier wave transmitted by the external reading device, and / or radio frequency signals from other external devices in the external environment, wherein the other external devices are different from the external reading device.

[0014] Optionally, the monitoring device further includes a timer trigger for periodically waking up the passive sensor to sense the target.

[0015] The beneficial effects of the embodiments of this application include: The monitoring equipment employs passive sensors, passively receiving changes in the external environment to determine the presence of a target. It requires no active transmission of detection signals or imaging of the target, keeping the power consumption of the sensing stage to the microwatt level. Furthermore, the communication unit uses backscatter communication. After receiving a carrier wave from an external reader, it transmits information back by impedance modulation of the carrier wave, eliminating the need for an internal active RF transmission link (such as a power amplifier, local oscillator, or transmitting circuit). The power consumption of the communication stage can also be controlled at the microwatt level. This combination of passive sensing and backscatter communication significantly reduces the overall power consumption of the monitoring equipment, requiring only microwatts of energy to complete the entire process of sensing, storage, and reporting, thus enabling long-term stable operation relying on ambient energy.

[0016] The monitoring equipment converts electromagnetic waves from the external environment into electrical energy through an energy management unit and stores it in an electric field energy storage unit. This electric field energy storage unit then powers the monitoring equipment, eliminating the need for a built-in chemical battery and enabling battery-free operation.

[0017] Since the monitoring equipment does not require a built-in chemical battery, it eliminates the need for a battery compartment, battery management circuitry, and the space they occupy, significantly reducing the size of the equipment. At the same time, it eliminates the cost of batteries and their associated power supply circuitry, and reduces the overall number of components, thereby lowering hardware costs.

[0018] Because the monitoring equipment does not require battery replacement or recycling, it reduces long-term operation and maintenance costs as well as labor costs. Its small size and low cost make it suitable for one-time, large-scale, and widespread deployment. The economic losses caused by the loss or damage of the equipment are negligible, making it particularly suitable for dense deployment in ecological protection areas, uninhabited areas, and other similar scenarios. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1This is a schematic diagram of the structure of the monitoring device provided in the embodiments of this application; Figure 2 This is a circuit diagram of the monitoring device provided in the embodiments of this application; Figure 3 This is a monitoring flowchart provided in the embodiments of this application.

[0021] Figure label: 10. Monitoring equipment; 101. Passive sensor; 102. Energy management unit; 103. Communication unit; 104. Electric field energy storage unit; 105. Event storage unit; 106. Control unit; 107. Receiving unit; 20. External reading device; 30. Other external equipment; Detailed Implementation The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. At the same time, in the description of the embodiments of this application, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0022] This application provides a monitoring device.

[0023] Specifically, please refer to Figure 1 The monitoring device 10 includes a passive sensor 101 (which may integrate an event decision unit), an energy management unit 102, a communication unit 103, an electric field energy storage unit 104, and an event storage unit 105.

[0024] The aforementioned electric field energy storage unit 104 supplies power to the aforementioned monitoring device 10. For example, the aforementioned electric field energy storage unit 104 supplies power to the aforementioned passive sensor 101, the aforementioned energy management unit 102, the aforementioned communication unit 103, and the aforementioned event storage unit 105.

[0025] The energy management unit 102 is used to convert electromagnetic waves from the external environment of the monitoring device 10 into electrical energy and store the electrical energy in the electric field energy storage unit 104.

[0026] The passive sensor 101 described above is used to generate a sensing event when a target is detected, and to store the sensing event in the event storage unit 105. The communication unit 103 is configured to send the sensed event in the event storage unit 105 to the external reading device 20 when it receives a carrier wave sent by the external reading device 20.

[0027] The electromagnetic waves mentioned above may include the carrier wave transmitted by the external reading device 20, and / or the radio frequency signals of other external devices 30 in the external environment, wherein the other external devices 30 are different from the external reading device 20. The carrier wave refers to a continuous sinusoidal radio frequency signal of a specific frequency (such as the 915MHz ISM band) transmitted by the external reading device 20. This signal serves two functions: first, to provide a reflected radio frequency source for backscatter communication; and second, to provide a wireless power source for the monitoring device 10.

[0028] The radio frequency signals of the other external devices 30 mentioned above may include, but are not limited to, Global System for Mobile Communications (GSM) base station signals, 4G base station signals, or 5G base station signals, and there are no restrictions on this.

[0029] For example, the energy management unit 102 supports dual-mode energy harvesting: the main mode is used to harvest energy from the ultra-high frequency (UHF) carrier transmitted by the external reading device 20; the auxiliary mode is used to harvest a small amount of energy (such as about 0.01~0.05 µW) from the radio frequency signals (such as GSM / 4G / 5G base station signals) of other external devices 30 to maintain ultra-low power operation in standby mode.

[0030] Specifically, such as Figure 2 As shown, the energy management unit 102 can receive radio frequency electromagnetic waves in space using an antenna (i.e., the receiving unit 107 of the monitoring device 10), and convert the radio frequency electromagnetic waves into DC power through a rectifier circuit (e.g., a voltage doubler rectifier circuit using Schottky diodes), and then store the DC power in the electric field energy storage unit 104. The electric field energy storage unit 104 is used to store the collected power.

[0031] For example, the electric field energy storage unit 104 can use a ceramic capacitor with a capacity of 1µF, which can provide approximately 0.25µJ of stored energy, sufficient to support a complete event reporting process (including sensing confirmation and backscatter communication). This application uses the electric field energy storage unit 104 to replace chemical energy storage devices such as batteries, realizing a battery-free design for the device; the electric field energy storage unit 104 does not require replacement and has no risk of chemical leakage, which can well meet the low-cost positioning application requirements for one-time deployment.

[0032] In some embodiments, the monitoring device 10 further includes a control unit 106, which is connected to the communication unit 103. The control unit 106 is configured to connect the electric field energy storage unit 104 and the communication unit 103 when it receives a carrier wave sent by the external reading device 20, so that the electric field energy storage unit 104 supplies power to the communication unit 103.

[0033] Specifically, an enable switch is provided between the electric field energy storage unit 104 and the subsequent circuit. In standby mode, the enable switch is open, and the electric field energy storage unit 104 is physically isolated from the subsequent circuit, with a leakage current of less than 1nA. When the control unit 106 receives a carrier wave sent by the external reading device 20, it connects the electric field energy storage unit 104 and the communication unit 103, so that the electric field energy storage unit 104 supplies power to the communication unit 103.

[0034] Among them, the passive sensor 101 refers to a sensing device that does not actively emit detection energy, but only detects changes in the physical quantities of the external environment. The aforementioned changes in the physical quantities of the external environment include, but are not limited to, changes in infrared radiation, microwave Doppler frequency shift, mechanical vibration, and acoustic disturbances, etc., and these changes in physical quantities can be triggered by a target passing by or approaching the detection device.

[0035] Therefore, the monitoring device 10 adopts a passive sensing architecture, which realizes the perception of the target's presence by detecting changes in environmental physical quantities caused by the target. Compared with the traditional monitoring mode that aims at image acquisition and video recording, the target presence perception only focuses on whether the target enters or moves within the monitoring area, and outputs a binary "present / absent" status signal, thereby significantly reducing the amount of data, processing power consumption and storage resource requirements.

[0036] Preferably, this application employs a passive infrared sensing method to implement a microwatt-level event-triggered detection mechanism.

[0037] For example, the passive sensor 101 of this application employs a dual-element pyroelectric infrared sensor (PIR). The PIR sensor itself does not actively emit any energy; it passively receives changes in infrared radiation from the external environment, with a typical detection wavelength range of 8–14 µm. When a target (such as a wild animal or a human) passes through the monitoring area, it causes a change in the amount of infrared radiation within the sensor's field of view. The sensor uses a dual-element structure and suppresses common-mode interference caused by overall changes in ambient temperature through differential amplification, outputting only the differential-mode signal caused by the target's movement.

[0038] Optionally, a silicon-based bandpass filter can be placed in front of the passive sensor 101, allowing only infrared radiation with wavelengths of 8–14 µm to pass through, and used in conjunction with a Fresnel lens array. The Fresnel lens array divides the monitoring area into multiple alternating sensitive zones (i.e., visible areas) and blind zones (i.e., invisible areas). When a target moves laterally within the monitoring area, it will sequentially enter the sensitive zone and the blind zone, causing the output of the passive sensor 101 to generate an alternating signal, thereby effectively distinguishing and detecting moving targets rather than static heat sources. The surface of the Fresnel lens has concentric ring patterns to achieve the aforementioned zoning of the monitoring area and focusing of infrared radiation.

[0039] Optionally, the passive sensor 101 also includes a signal conditioning circuit, which includes an analog bandpass filter (e.g., with a bandwidth of 0.1 Hz to 10 Hz) to filter out DC drift and high-frequency noise. The analog differential signal output by the passive sensor 101 does not need to be quantized by an analog-to-digital converter and can be directly sent to the subsequent comparator for processing, thereby reducing system power consumption.

[0040] Optionally, a photoresistor can be installed inside the monitoring device 10. The photoresistor shares the same window with the passive sensor 101 to detect ambient illuminance, thereby achieving adaptive adjustment of day and night modes. For example, when the illuminance is greater than 100 lux (daytime), baseline drift caused by solar infrared radiation may be superimposed on the PIR output signal. In this case, the low-frequency cutoff frequency of the analog bandpass filter can be increased from 0.1 Hz to 0.5 Hz to filter out slowly changing baseline components. When the illuminance is less than 100 lux (nighttime), the low-frequency cutoff frequency returns to 0.1 Hz to maintain the detection sensitivity for slow-moving targets. It is understood that the above illuminance threshold and frequency parameters are merely examples, and those skilled in the art can make appropriate adjustments according to actual application requirements.

[0041] In some embodiments, the passive sensor 101 is further configured to generate a differential mode electrical signal based on the sensed signal, and determine the presence of a target when the differential mode electrical signal meets preset conditions.

[0042] The aforementioned preset conditions include: the differential mode electrical signal is greater than the signal threshold within a preset number of consecutive time windows; wherein the preset number and the signal threshold are determined based on the temperature of the environment in which the monitoring device 10 is located.

[0043] Optionally, the monitoring device 10 also includes a thermistor. This thermistor can be used not only for adaptive adjustment of the signal threshold but also for detecting the rate of change of ambient temperature. For example, when the ambient temperature changes by more than 5°C within one hour (e.g., rapid temperature rise due to sunrise in the morning), the device will temporarily increase the number of time windows from "2 consecutive windows" to "3 consecutive windows" to reduce the risk of batch false alarms caused by hot airflow disturbances; once the rate of change of ambient temperature stabilizes, the number of time windows will be restored to 2.

[0044] Optionally, the passive sensor 101 also includes an adaptive threshold comparator and a time window confirmation circuit for implementing three-level event confirmation: First stage: The signal is filtered by an analog bandpass filter (0.1 Hz to 10 Hz) to eliminate DC drift and suppress high-frequency noise; The second stage: The differential mode electrical signal is compared with the signal threshold by an adaptive threshold comparator. The signal threshold is dynamically adjusted according to the ambient temperature monitored by the thermistor. The higher the ambient temperature, the higher the threshold is, so as to reduce false alarms under high temperature conditions. Level 3: Time window confirmation, which requires the differential mode electrical signal to remain above the signal threshold for a preset number of consecutive time windows (e.g., each window is 20 ms) before it is confirmed as a valid event, thereby filtering out false triggers caused by single pulses (such as the rustling of grass).

[0045] Optionally, the preset number is determined based on the rate of change of ambient temperature. For example, when the ambient temperature changes by more than 5°C within 1 hour (e.g., rapid temperature rise at sunrise), the device temporarily increases the number of time window confirmations from "2 consecutive windows" to "3 consecutive windows" to avoid batch false alarms caused by hot airflow disturbances; once the rate of change of temperature stabilizes, the number of time window confirmations is restored to 2.

[0046] Optionally, the passive sensor 101 can also be used to distinguish the size of the target. The amplitude of the PIR differential signal is positively correlated with the target's speed and size, and the signal amplitude can be divided into three threshold levels: low, medium, and high.

[0047] For example, the signal amplitudes generated by wild boars (weighing more than 50 kg) and deer (weighing more than 30 kg) typically exceed the medium threshold; while the signal amplitudes generated by rodents and birds (weighing less than 5 kg) typically fall below the low threshold. The passive sensor 101 can be configured to trigger counting only when a valid signal reaching or exceeding the medium threshold is detected, thereby filtering out non-target small animals. This configuration can be achieved by sending corresponding configuration parameters from an external reading device.

[0048] The aforementioned communication unit 103 is used to send the sensed event in the event storage unit 105 to the external reading device 20 upon receiving a carrier wave sent by the external reading device. The communication unit 103 employs a backscatter communication method: the device itself does not actively generate or transmit radio frequency carrier waves, but instead dynamically changes the load impedance of the antenna terminal (e.g., switching between a high-impedance state and a 50Ω matching state) to alter the reflection coefficient of the incident spatial carrier wave (provided by the external reading device). The external reading device 20 demodulates the information transmitted back by the device by detecting changes in the amplitude or phase of the reflected signal. This method avoids the need for a built-in active radio frequency transmitter and is the core foundation for achieving microwatt-level power consumption.

[0049] For example, the communication unit 103 employs a dual-state impedance modulation network: State 0: connected to a 50Ω matched load (absorbing the carrier for charging, with a reflection coefficient of approximately 0); State 1: connected to a high-impedance state (maximizing the reflected signal, with a reflection coefficient of approximately 1).

[0050] The switching time between the two states is less than 1µs.

[0051] The antenna can be time-division multiplexed in the time domain: during the transmission of the carrier by the external reading device 20, the antenna is simultaneously connected to the energy harvesting rectifier circuit and the backscatter modulation switch, and parallel operation of charging and communication is achieved by controlling state 0 (matched absorption) and state 1 (high impedance reflection).

[0052] The aforementioned communication unit 103 is further configured to, upon receiving a carrier wave transmitted by the external reading device 20, encode the aforementioned sensing event in the aforementioned event storage unit 105 and the voltage of the aforementioned electric field energy storage unit 104 according to a target encoding method to obtain target encoding information, and transmit the aforementioned target encoding information to the aforementioned external reading device 20; wherein, the aforementioned target encoding method is determined based on the voltage of the aforementioned electric field energy storage unit 104.

[0053] Specifically, when the voltage of the electric field energy storage unit 104 is equal to or greater than the first voltage value, the target encoding method is the first encoding method; when the voltage of the electric field energy storage unit 104 is equal to or greater than the second voltage value and less than the first voltage value, the target encoding method is the second encoding method; when the voltage of the electric field energy storage unit 104 is less than the second voltage value, the sensing event is not transmitted; wherein, the communication rate of the second encoding method is less than the communication rate of the first encoding method.

[0054] For example, the explanation will be given with a first voltage value of 1.8V, a second voltage value of 1.2V, a first encoding method of Manchester encoding, and a second encoding method of Pulse Width Modulation (PWM).

[0055] When the voltage of the aforementioned electric field energy storage unit 104 is equal to or greater than 1.8V, Manchester encoding is used for encoding. Manchester encoding includes a transition edge in each symbol period, has strong anti-interference capability, and is suitable for communication when there is sufficient carrier wave.

[0056] When the voltage of the aforementioned electric field energy storage unit 104 is equal to or greater than 1.2V and less than 1.8V, PWM encoding is used. PWM encoding represents information by adjusting the pulse width, resulting in higher energy efficiency and making it suitable for prioritizing communication success when energy is insufficient.

[0057] If the voltage of the aforementioned electric field energy storage unit 104 is less than 1.2V, the aforementioned sensing event will not be transmitted, the event count will be maintained, and the event will be retransmitted when the energy is restored or the next carrier arrives.

[0058] Optionally, the monitoring device 10 also includes a low power protection mechanism: when the voltage of the electric field energy storage unit 104 is lower than the operating threshold (e.g., 1.2V, corresponding to the second voltage value), the device automatically shields the event trigger signal, does not respond to the sensing event, and only maintains the minimum environmental energy collection; after the voltage rises back to the recovery threshold (e.g., 1.5V) or above, the event detection function is automatically restored.

[0059] In some embodiments, when the target encoding method is the first encoding method, the communication unit 103 is further configured to determine the encoding rate in the first encoding method based on the voltage obtained by converting the signal strength of the carrier wave; and to encode the sensing event in the event storage unit 105 and the voltage of the electric field energy storage unit 104 using the first encoding method and the encoding rate to obtain target encoding information.

[0060] The voltage obtained from the above carrier signal strength conversion can be regarded as the detection voltage. For example, the voltage can be obtained by detecting the received carrier through a detection diode.

[0061] For example, when the detection voltage is greater than 500 mV, it can be determined as short-range communication (e.g., distance less than 5 m), and full-rate Manchester encoding is used; when the detection voltage is in the range of 200 mV to 500 mV, it can be determined as medium- to long-range communication, and the system automatically reduces the encoding rate to 1 / 2 of the original rate to extend the duration of each bit symbol and improve the demodulation signal-to-noise ratio, thereby compensating for the reflection attenuation caused by vegetation (such as leaves and shrubs).

[0062] Optionally, the communication unit 103 also includes an impedance matching network with temperature drift compensation capability: the capacitors in the antenna matching network are made of NPO / C0G material (temperature coefficient of 0±30 ppm / °C) to ensure that the antenna reflection coefficient changes by no more than ±5% within the outdoor ambient temperature range of -25°C to +50°C. Simultaneously, a varactor diode is connected in series in the matching network, and a bias voltage is output after sampling the ambient temperature through a thermistor to automatically fine-tune the matching point, thereby ensuring the consistency of antenna reflection efficiency under different seasonal conditions.

[0063] Optionally, the communication unit 103 also includes a multipath protection mechanism: in addition to inserting a 5 µs guard interval in the backscatter frame to avoid inter-symbol interference caused by field multipath effects, a 4-bit preamble (e.g., 1010) is added to the frame header of the backscatter frame for external reading devices to perform channel estimation, to identify and eliminate the effects of fixed multipath reflection paths (such as ground reflection), and to demodulate only the signal changes caused by dynamic targets.

[0064] In some embodiments, the control unit is also connected to the passive sensor 101. The passive sensor 101 described above is also used to generate a sensing event when a target is detected, and to send the sensing event to the control unit. The control unit is also configured to increment the count result in the event counter in the event storage unit 105 upon receiving the aforementioned sensing event; The aforementioned communication unit 103 is also used to send the counting result of the aforementioned event counter to the aforementioned external reading device 20.

[0065] Optionally, if the external reading device 20 is not present (i.e., no carrier), the monitoring device 10 cannot send information, but the event counter will still accumulate and be stored in the event storage unit 105. The next time the external reading device 20 transmits a carrier, the monitoring device 10 will prioritize retransmitting the accumulated event count, expressed in a continuous counting manner. This mechanism frees the device from the traditional RFID constraint that the reader must be continuously powered, upgrading backscatter communication from real-time response to event buffering asynchronous reporting.

[0066] For a better understanding of the above scheme, please refer to [link / reference]. Figure 3 The following is a description with reference to specific embodiments: T0 (0ms): The differential output of passive sensor 101 exceeds the adaptive threshold, triggering a level 3 event confirmation process; T0+20ms: If the differential mode electrical signal continues to exceed the signal threshold within the first 20ms time window, the second 20ms time window is started. T0+40ms: If a differential mode electrical signal exceeding the signal threshold is still detected within the second time window, the event is deemed valid. The control unit 106 immediately latches the current event counter (increments by 1) and reads the voltage of the electric field energy storage unit 104; T0+40ms~T0+45ms (5ms decision window): When the voltage of the electric field energy storage unit 104 is ≥1.8V, Manchester encoding is selected to obtain the highest communication rate; When the voltage of the electric field energy storage unit 104 is in the range of 1.2V to 1.8V, PWM encoding is selected to prioritize communication success rate. When the voltage of the electric field energy storage unit 104 is <1.2V, the power protection mechanism is triggered. This event will not be transmitted, but the event counter has been incremented by 1 and written into the event storage unit 105 (ultra-low power register) for retransmission when the subsequent carrier arrives. T0+45ms: The control unit 106 outputs an enable signal to connect the power path between the electric field energy storage unit 104 and the communication unit 103; T0+45ms~T0+55ms (10ms communication window): Communication unit 103 completes impedance switching and encodes and sends the three fields "Device ID (16bit) + Event Counter (8bit) + Electric Field Energy Storage Unit Voltage (4bit)"; Optionally, a preamble and a checksum can also be added, with a total length of 36 bits; T0+55ms: Communication ends, control unit 106 cuts off power supply from electric field energy storage unit 104 to communication unit 103, and monitoring device 10 returns to standby listening state.

[0067] In some embodiments, the monitoring device 10 further includes a timer trigger for periodically waking up the passive sensor 101 to sense a target.

[0068] To reduce average power consumption, the monitoring device 10 adopts an intermittent working mode, alternating between wake-up monitoring and deep sleep states within a fixed period.

[0069] For example, the monitoring device 10 operates on a 24-hour cycle, waking up every 10 seconds for approximately 50 ms each time, and remaining in deep sleep mode for the rest of the time (power consumption approximately 0.01 µW), thereby reducing the average standby power consumption from approximately 0.1 µW to approximately 0.0105 µW. Specifically, the average power consumption during the listening phase is 0.1 µW × (50 ms / 10 s) = 0.0005 µW, and after adding the deep sleep power consumption of 0.01 µW, the average standby power consumption is approximately 0.0105 µW.

[0070] Assuming that external reading device 20 operates for only 1 hour per day, providing approximately 28 dBm carrier during that period; and that monitoring device 10 relies solely on ambient radio frequency energy (typically approximately 0.03 µW) to maintain standby for the remaining 23 hours, then during the 23-hour standby period, the energy consumption of monitoring device 10 is 23 h × 0.0105 µW = 0.2415 µWh; the ambient radio frequency energy collected during the same period is 23 h × 0.03 µW = 0.69 µWh; and during the 1 hour when reading device 20 is powered, monitoring device 10 can collect an additional 1 h × 0.2 µW = 0.2 µWh of energy.

[0071] Therefore, the total daily energy collected by monitoring device 10 is approximately 0.89 µWh, while the total daily energy consumption is approximately 0.2415 µWh, resulting in a daily energy surplus of approximately 0.65 µWh. This surplus can be stored in a capacitor of approximately 1 µF to support occasional multiple event reports. The above calculations show that even under extreme operating conditions where external reading device 20 operates for only 1 hour per day, monitoring device 10 can still achieve energy balance.

[0072] It should be noted that the power consumption, energy, and time parameters mentioned above are merely illustrative examples, and those skilled in the art can make appropriate adjustments to the relevant parameters based on the actual device selection and specific application requirements.

[0073] Thus, the following beneficial effects can be achieved through the aforementioned monitoring equipment: The monitoring equipment employs passive sensors, passively receiving changes in the external environment to determine the presence of a target. It requires no active transmission of detection signals or imaging of the target, keeping the power consumption of the sensing stage to the microwatt level. Furthermore, the communication unit uses backscatter communication. After receiving a carrier wave from an external reader, it transmits information back by impedance modulation of the carrier wave, eliminating the need for an internal active RF transmission link (such as a power amplifier, local oscillator, or transmitting circuit). The power consumption of the communication stage can also be controlled at the microwatt level. This combination of passive sensing and backscatter communication significantly reduces the overall power consumption of the monitoring equipment, requiring only microwatts of energy to complete the entire process of sensing, storage, and reporting, thus enabling long-term stable operation relying on ambient energy.

[0074] The monitoring equipment converts electromagnetic waves from the external environment into electrical energy through an energy management unit and stores it in an electric field energy storage unit. This electric field energy storage unit then powers the monitoring equipment, eliminating the need for a built-in chemical battery and enabling battery-free operation.

[0075] Since the monitoring equipment does not require a built-in chemical battery, it eliminates the need for a battery compartment, battery management circuitry, and the space they occupy, significantly reducing the size of the equipment. At the same time, it eliminates the cost of batteries and their associated power supply circuitry, and reduces the overall number of components, thereby lowering hardware costs.

[0076] Because the monitoring equipment does not require battery replacement or recycling, it reduces long-term operation and maintenance costs as well as labor costs. Its small size and low cost make it suitable for one-time, large-scale, and widespread deployment. The economic losses caused by the loss or damage of the equipment are negligible, making it particularly suitable for dense deployment in ecological protection areas, uninhabited areas, and other similar scenarios.

[0077] It should be noted that each monitoring device can be programmed with a unique 16-bit ID at the factory, which can distinguish up to 65,536 monitoring devices. This ID field contains grouping information, where the high 4 bits are used to indicate the area group and the low 12 bits are used to indicate the monitoring device number.

[0078] When multiple monitoring devices are simultaneously activated by the carrier of an external reader, the system employs a random timeslot access mechanism. Before transmission, each monitoring device generates a random number between 0 and 15 and multiplies it by 10 ms as a random backoff delay. After backoff, the monitoring device listens for reflected signals from other monitoring devices on the carrier channel (achieved through energy detection): if the channel is idle, it transmits immediately; if the channel is busy, it re-enters the backoff process. This access protocol is implemented passively at the monitoring device level, requiring no additional scheduling of monitoring devices by the external reader.

[0079] The user walks along the animal trail with a handheld external reading device at a speed of approximately 1 m / s. The external reading device has a transmission power of 20 dBm (EIRP), a coverage radius of approximately 15 m, and operates in continuous reception mode. The device receives reflected signals from all monitoring devices within the coverage area, roughly estimates the location of the monitoring devices based on the signal arrival time difference or signal strength, and generates a corresponding heat map on the handheld terminal.

[0080] When the same target triggers monitoring device A and monitoring device B within 5 seconds, the external reading device determines that the target is the same entity and passes through different points sequentially based on the IDs of the two monitoring devices and the time difference of signal arrival. The system presents the target's movement trajectory on the heat map by connecting lines, rather than simply accumulating trigger counts, thus effectively avoiding duplicate statistics.

[0081] Based on the monitoring equipment mentioned above, the following monitoring methods can also be used.

[0082] Specifically, the above monitoring method is applied to monitoring equipment. The monitoring equipment includes passive sensors, an energy management unit, a communication unit, an electric field energy storage unit, and an event storage unit, with the electric field energy storage unit supplying power to the passive sensors, energy management unit, communication unit, and event storage unit, respectively.

[0083] The energy management unit converts electromagnetic waves from the external environment of the monitoring equipment into electrical energy and stores the electrical energy in the electric field energy storage unit. When a target is detected by a passive sensor, a sensing event is generated and stored in an event storage unit. Upon receiving a carrier wave from an external reading device via the communication unit, the sensed events in the event storage unit are sent to the external reading device.

[0084] Optionally, through the communication unit, upon receiving a carrier wave sent by an external reading device, the sensing events in the event storage unit and the voltage of the electric field energy storage unit are encoded according to the target encoding method to obtain target encoding information, and the target encoding information is sent to the external reading device; wherein, the target encoding method is determined based on the voltage of the electric field energy storage unit.

[0085] Optionally, when the voltage of the electric field energy storage unit is equal to or greater than the first voltage value, the target encoding method is the first encoding method; when the voltage of the electric field energy storage unit is equal to or greater than the second voltage value and less than the first voltage value, the target encoding method is the second encoding method; when the voltage of the electric field energy storage unit is less than the second voltage value, no sensing event is sent; wherein, the communication rate of the second encoding method is less than the communication rate of the first encoding method.

[0086] Optionally, when the target encoding method is the first encoding method, the encoding rate in the first encoding method is determined by the communication unit based on the voltage converted from the signal strength of the carrier wave; the first encoding method and the encoding rate are used to encode the sensing events in the event storage unit and the voltage of the electric field energy storage unit to obtain the target encoding information.

[0087] Optionally, the monitoring device also includes a control unit connected to the communication unit. Upon receiving a carrier wave from an external reading device, the control unit connects the electric field energy storage unit to the communication unit, enabling the electric field energy storage unit to supply power to the communication unit.

[0088] Optionally, the control unit is also connected to a passive sensor; When a target is detected by a passive sensor, a sensing event is generated and sent to the control unit. Upon receiving a perceived event, the control unit increments the count in the event counter of the event storage unit. The event counter's count result is sent to an external reading device via the communication unit.

[0089] Optionally, a passive sensor is used to generate a differential mode electrical signal based on the sensed signal, and the presence of a target is determined when the differential mode electrical signal meets preset conditions.

[0090] Optionally, the preset conditions include: the differential mode electrical signal is greater than the signal threshold within a preset number of consecutive time windows; wherein the preset number and the signal threshold are determined based on the temperature of the environment in which the monitoring device is located.

[0091] Optionally, the monitoring device also includes a timer trigger that periodically wakes up the passive sensor to sense the target.

[0092] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be performed by instructions, or by instructions controlling related hardware. These instructions can be stored in a computer-readable storage medium and loaded and executed by a processor.

[0093] Therefore, embodiments of this application also provide a computer-readable storage medium storing a computer program or instructions thereon, which is loaded by a processor to perform the steps described in the above-described method embodiments of this application. For example, the computer program or instructions loaded by the processor can perform the following steps: The energy management unit converts electromagnetic waves from the external environment of the monitoring equipment into electrical energy and stores the electrical energy in the electric field energy storage unit. By using passive sensors, when a target is detected, a sensing event is generated and stored in the event storage unit; The communication unit sends the sensed events in the event storage unit to the external reading device upon receiving a carrier wave from the external reading device.

[0094] For details on the implementation of each of the above operations / steps, please refer to the previous examples, which will not be repeated here.

[0095] The computer-readable storage medium may include: read-only memory (ROM), random access memory (RAM), disk or optical disk, etc.

[0096] Since the computer program stored in the computer-readable storage medium can execute the steps in any of the above method embodiments provided in the embodiments of this application, the beneficial effects that the methods described in any of the above method embodiments can achieve can be realized, as detailed in the preceding embodiments, and will not be repeated here.

[0097] This application also provides a computer program product or computer program that includes computer instructions stored in a computer-readable storage medium. A processor of an electronic device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the electronic device to perform the methods provided in the various optional implementations of the above embodiments.

[0098] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the detailed descriptions of other embodiments above, which will not be repeated here.

[0099] In practice, each of the above units or structures can be implemented as an independent entity or can be arbitrarily combined to be implemented as the same or several entities. For the specific implementation of each of the above units or structures, please refer to the previous method embodiments, which will not be repeated here.

[0100] The monitoring device, monitoring method, and storage medium provided in the embodiments of this application have been described in detail above. Specific examples have been used in this application to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A monitoring device, characterized in that, The monitoring device includes a passive sensor, an energy management unit, a communication unit, an electric field energy storage unit, and an event storage unit. The electric field energy storage unit supplies power to the passive sensor, the energy management unit, the communication unit, and the event storage unit, respectively. The energy management unit is used to convert electromagnetic waves from the external environment of the monitoring device into electrical energy and store the electrical energy in the electric field energy storage unit. The passive sensor is used to generate a sensing event when a target is detected, and to store the sensing event in the event storage unit. The communication unit is configured to send the sensed event in the event storage unit to the external reading device upon receiving a carrier wave sent by the external reading device.

2. The monitoring device according to claim 1, characterized in that, The communication unit is further configured to, upon receiving a carrier wave sent by an external reading device, encode the sensing event in the event storage unit and the voltage of the electric field energy storage unit according to a target encoding method to obtain target encoding information, and send the target encoding information to the external reading device; The target encoding method is determined based on the voltage of the electric field energy storage unit.

3. The monitoring device according to claim 2, characterized in that, When the voltage of the electric field energy storage unit is equal to or greater than the first voltage value, the target encoding method is the first encoding method; When the voltage of the electric field energy storage unit is equal to or greater than the second voltage value and less than the first voltage value, the target encoding method is the second encoding method; If the voltage of the electric field energy storage unit is less than the second voltage value, the sensing event will not be sent. The communication rate of the second encoding method is less than that of the first encoding method.

4. The monitoring device according to claim 3, characterized in that, When the target encoding method is the first encoding method, the communication unit is further configured to determine the encoding rate in the first encoding method based on the voltage obtained by converting the signal strength of the carrier; and to encode the sensing event in the event storage unit and the voltage of the electric field energy storage unit using the first encoding method and the encoding rate to obtain target encoding information.

5. The monitoring device according to claim 1, characterized in that, The monitoring device also includes a control unit, which is connected to the communication unit; The control unit is configured to connect the electric field energy storage unit and the communication unit upon receiving a carrier wave sent by the external reading device, so that the electric field energy storage unit supplies power to the communication unit.

6. The monitoring device according to claim 5, characterized in that, The control unit is also connected to the passive sensor; The passive sensor is also used to generate a sensing event when a target is detected, and to send the sensing event to the control unit. The control unit is further configured to increment the count result in the event counter in the event storage unit upon receiving the perceived event; The communication unit is also used to send the counting result of the event counter to the external reading device.

7. The monitoring device according to any one of claims 1 to 6, characterized in that, The passive sensor is also used to generate a differential mode electrical signal based on the sensed signal, and to determine the presence of a target when the differential mode electrical signal meets preset conditions.

8. The monitoring device according to claim 7, characterized in that, The preset conditions include: the differential mode electrical signal is greater than the signal threshold within a preset number of consecutive time windows; The preset quantity and the signal threshold are determined based on the temperature of the environment in which the monitoring device is located.

9. The monitoring device according to any one of claims 1 to 6, characterized in that, The electromagnetic waves include a carrier wave transmitted by the external reading device, and / or radio frequency signals from other external devices in the external environment, wherein the other external devices are different from the external reading device.

10. The monitoring device according to any one of claims 1 to 6, characterized in that, The monitoring device also includes a timer trigger, which is used to periodically wake up the passive sensor to sense the target.

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