A multi-mode intelligent protection circuit for a power supply of a drone

Abstract

The application relates to a multi-mode intelligent protection circuit for a power supply of a UAV, and relates to the technical field of the power supply of the UAV.The multi-mode intelligent protection circuit comprises a multi-parameter high-precision detection network, which is used for collecting voltage, current and temperature information of a power supply bus in real time.The application constructs a cooperative system which integrates a multi-parameter high-precision detection network, a microprocessor intelligent decision unit, a fast response execution module and a high-reliability power supply module, thereby comprehensively improving the adaptability and reliability of the power supply of the UAV under complex flight conditions.The system can dynamically adjust overcurrent, overvoltage, undervoltage and other protection thresholds according to real-time flight modes, environmental temperatures and load changes, effectively avoiding the problems of misoperation or protection lag of traditional fixed threshold protection under extreme working conditions;in combination with a temperature control model based on a Bayesian network algorithm and a graphene heating film active temperature control system, the accurate monitoring and fast self-recovery capability of the power supply state under an ultralow-temperature environment are significantly improved.

Description

Technical Field

[0001] This application relates to the field of drone power supply technology, and in particular to a multi-mode intelligent protection circuit for drone power supplies. Background Technology

[0002] When drones perform tasks such as inspection, surveying, aerial photography, and even logistics transportation, their flight environment is complex and changeable. The power system needs to cope with drastic load changes, extreme temperature fluctuations, and potential electromagnetic interference. These factors can easily cause power system failures such as instantaneous overcurrent, overvoltage, undervoltage, or even short circuits. Once the power system fails, it may lead to mission interruption and forced landing of the drone, or even equipment damage or safety accidents.

[0003] Existing drones typically employ simple protection circuits, such as voltage comparators with fixed thresholds or basic fuses. These protection schemes have rigid response mechanisms and cannot adapt to dynamically changing flight conditions. For example, when a drone accelerates to climb or encounters strong winds requiring high power output, the fixed overcurrent protection threshold may be set too low, causing malfunctions and unnecessary power interruptions. Conversely, if the threshold is set too high, it may not provide timely protection when a real fault occurs. Furthermore, traditional protection circuits lack consideration for temperature factors and the flexibility to switch protection strategies in different mission modes, resulting in insufficient reliability. Especially in high-altitude, high-latitude, and other frigid regions, power systems face even more severe challenges. In extremely low-temperature scenarios, lithium-ion power supplies suffer from insufficient dynamics, and conventional power supplies cannot charge or discharge. Traditional protection circuits are completely unable to solve the problems of inaccurate protection parameters and system startup failures caused by battery performance degradation at low temperatures. Therefore, existing technologies suffer from the core defects of fixed protection strategies and an inability to intelligently adapt to complex operating conditions and environmental changes. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a multi-mode intelligent protection circuit for drone power supplies.

[0005] This application provides a multi-mode intelligent protection circuit for drone power supplies, which adopts the following technical solution: A multi-mode intelligent protection circuit for drone power supplies includes: A multi-parameter high-precision detection network is used to collect voltage, current and temperature information of the power bus in real time. A microprocessor unit, which is connected to the multi-parameter high-precision detection network, is used to execute a multi-mode protection logic algorithm based on the detection data. A fast response execution module is connected to the microprocessor unit and is used to control the on / off state of the main circuit according to the protection signal. A high-reliability power supply module is electrically connected to the multi-parameter high-precision detection network, the microprocessor unit, and the fast-response execution module. The high-reliability power supply module is used to provide a stable operating voltage for the multi-parameter high-precision detection network, the microprocessor unit, and the fast-response execution module.

[0006] As a preferred technical solution of this application, the multi-parameter high-precision detection network includes: A voltage sampling circuit, wherein the voltage sampling circuit uses a high-precision voltage divider resistor network and an analog-to-digital converter to acquire voltage signals; A current sampling circuit, wherein the current sampling circuit uses a precision sampling resistor and a differential amplifier or a Hall effect current sensor to achieve current measurement; A temperature sampling circuit is provided, wherein a negative temperature coefficient thermistor is arranged at the interface between the power device and the battery.

[0007] As a preferred technical solution of this application, the microprocessor unit has built-in multi-mode protection logic, which includes an automatic mode, a manual mode, and a fault diagnosis and recording function. The automatic mode dynamically adjusts the protection thresholds for overcurrent, overvoltage, and undervoltage based on real-time flight data and ambient temperature. The manual mode selects a preset protection strategy through ground station or remote controller commands. The fault diagnosis and recording function is used to distinguish fault types and record fault data.

[0008] As a preferred technical solution of this application, the fast response execution module includes: A power switching circuit, wherein the power switching circuit uses an N-MOSFET with low on-resistance as an electronic switch; A gate driver chip, which is used to amplify the protection signal of the microprocessor to quickly control the switching on and off of the MOSFET.

[0009] As a preferred technical solution of this application, the high-reliability power supply module adopts an architecture combining a charge pump circuit and a low-dropout linear regulator to provide stable low-voltage power supply for the microprocessor and sensors.

[0010] As a preferred technical solution of this application, the output end of the high-reliability power supply module is also designed with a compatibility interface. The compatibility interface supports multiple UAV power interface standards and communication protocols and can be adapted through jumper caps or software configuration.

[0011] As a preferred technical solution of this application, the multi-mode protection logic also includes a temperature control model based on a Bayesian network algorithm, which is used to achieve accurate detection and dynamic adjustment of SOX parameters in ultra-low temperature environments.

[0012] As a preferred technical solution of this application, the multi-parameter high-precision detection network integrates a graphene heating film and a heat spreader. The graphene heating film and heat spreader are used to quickly increase the battery temperature in a low-temperature environment, ensuring that the power system can work normally in a low-temperature environment.

[0013] As a preferred technical solution of this application, the microprocessor unit is also configured with an active self-balancing function, which achieves precise equalization control of the energy of multiple battery cells through a high-precision BMS algorithm.

[0014] In summary, this application includes at least one of the following beneficial technical effects for a multi-mode intelligent protection circuit for drone power supplies: This application constructs a collaborative system integrating a multi-parameter high-precision detection network, a microprocessor intelligent decision-making unit, a fast-response execution module, and a high-reliability power supply module. This system comprehensively enhances the adaptability and reliability of UAV power supplies under complex flight conditions. The system can dynamically adjust protection thresholds such as overcurrent, overvoltage, and undervoltage based on real-time flight modes, ambient temperature, and load changes, effectively avoiding the malfunctions or protection lag issues of traditional fixed-threshold protection under extreme conditions. Combined with a temperature control model based on Bayesian network algorithms and a graphene heating film active temperature control system, the system significantly enhances the accurate monitoring and rapid self-recovery capabilities of the power supply status in ultra-low temperature environments, ensuring stable operation under extremely cold conditions. At the same time, through the cascaded power supply design of charge pumps and low-dropout linear regulators at the hardware level, a fast-response switching circuit with multiple MOSFETs in parallel, and fault diagnosis and black box recording functions at the software level, the system's anti-interference capability, response speed, and maintainability are further improved. Ultimately, this circuit realizes the leap from "passive response" to "active adaptation" in UAV power supply protection, providing highly reliable energy security for scenarios such as high-altitude and cold-region inspection, logistics transportation, and emergency rescue. Attached Figure Description

[0015] Figure 1 This is a diagram of the multi-mode intelligent protection circuit system architecture of this application. Detailed Implementation

[0016] The following is in conjunction with the appendix Figure 1 This application will be described in further detail.

[0017] See Figure 1 A multi-mode intelligent protection circuit for drone power supplies, comprising: A multi-parameter high-precision detection network is used to acquire voltage, current, and temperature information of the power bus in real time. The network includes: a voltage sampling circuit, which uses a high-precision voltage divider resistor network and an analog-to-digital converter to acquire voltage signals; a current sampling circuit, which uses precision sampling resistors and differential amplifiers or Hall effect current sensors to measure current; and a temperature sampling circuit, which uses negative temperature coefficient thermistors placed at the power device and battery interface. The network also integrates a graphene heating film and a heat spreader, which are used to rapidly raise the battery temperature in low-temperature environments, ensuring the power system can operate normally in such conditions.

[0018] A multi-parameter high-precision detection network is used to achieve comprehensive and highly reliable monitoring of the power bus status, providing an accurate data foundation for subsequent intelligent decision-making. The voltage sampling circuit adopts a voltage divider network composed of high-precision, low-temperature drift metal film resistors (e.g., 0.1% accuracy, 25ppm / ℃). For example, a combination of 1MΩ and 56kΩ resistors is used to divide the bus voltage up to 60V by approximately 18.86:1. The divided signal is directly connected to the analog-to-digital converter (ADC) pin of the microprocessor. To improve sampling accuracy and anti-interference, an RC low-pass filter (e.g., a 100Ω resistor and a 100nF capacitor, with a cutoff frequency of approximately 16kHz) is designed at the front end of the ADC to suppress high-frequency noise. An external high-precision reference voltage source (e.g., REF5030, 3.0V, 3ppm / ℃) is used as the ADC reference. At the same time, an offset and gain compensation algorithm based on factory calibration is introduced at the software level to ensure that the voltage measurement error is less than 0.5%. Current sampling offers two precision options: Option 1 is based on a sampling resistor and a differential amplifier. A 2mΩ, 1W precision sampling resistor is connected in series in the main circuit, and a high common-mode rejection ratio (CMRR) differential amplifier (such as INA240, with a gain set to 50V / V) is used to amplify the voltage drop across the sampling resistor. This option is low-cost and highly accurate, but suffers from I²R power loss. Option 2 uses a Hall effect current sensor (such as ACS723) to achieve isolated and lossless current measurement. However, attention must be paid to its zero-drift temperature compensation. Temperature sampling is achieved by using a negative temperature coefficient (NTC) thermistor deployed on the battery interface and the power MOSFET heatsink to form a voltage divider circuit with a precision fixed resistor. The MCU reads the voltage divider value through the ADC and uses the Steinhart-Hart equation (1 / T) to... =A+Bln(R)+C[ln(R)]³, where T is the Kelvin temperature, R is the NTC resistance, and A, B, and C are device-specific parameters) or the temperature value can be accurately calculated using a lookup table method. For low-temperature environments, this network integrates an innovative active temperature control system: a graphene heating film is attached to the PCB or battery contact surface, which is controlled by the MCU through PWM power control via MOSFET switching; at the same time, a heat spreader is added between the heat source and the heated body to ensure rapid and uniform heat diffusion; when the ambient temperature sensor detects that the temperature is lower than the set threshold (e.g., -10°C), the MCU starts the temperature control logic, and by adjusting the PWM duty cycle, the operating temperature of the battery or key components is stably raised to a suitable range (e.g., above 10°C), fundamentally ensuring the measurement accuracy of the sensor at ultra-low temperatures and the startup and operation reliability of the power system.

[0019] The microprocessor unit is connected to a multi-parameter high-precision detection network. The microprocessor unit executes multi-mode protection logic algorithms based on the detection data. The microprocessor unit incorporates multi-mode protection logic, including automatic mode, manual mode, and fault diagnosis and recording functions. Automatic mode dynamically adjusts overcurrent, overvoltage, and undervoltage protection thresholds based on real-time flight data and ambient temperature. Manual mode allows selection of preset protection strategies via ground station or remote controller commands. The fault diagnosis and recording function distinguishes fault types and records fault data. The multi-mode protection logic also includes a temperature control model based on a Bayesian network algorithm, which enables accurate detection and dynamic adjustment of SOX parameters in ultra-low temperature environments. The microprocessor unit is also equipped with an active self-balancing function, which uses a high-precision BMS algorithm to achieve precise energy balance control of multiple battery cells.

[0020] The microprocessor unit performs real-time analysis, reasoning, and decision-making on the detected data to achieve intelligent adaptive protection. The core of the microprocessor unit is a multi-mode protection logic state machine, which mainly includes three operating modes: In automatic mode, the microprocessor acquires flight control data (such as throttle, flight mode, and load status) and ambient temperature in real time through a compatibility interface (such as CAN or UART), and dynamically calculates the protection threshold. For example, the overcurrent protection threshold I_ocp = I_base * K_temp * K_mode * K_load, where I_base is the battery's nominal continuous current, and K_temp is a compensation coefficient obtained based on a temperature lookup table (e.g., 0°C). C is 0.8), K_mode is a coefficient related to the flight mode (e.g., 1.2 for takeoff mode), K_load is the load device switching state coefficient, and the undervoltage protection threshold V_uvp = V_cutoff_base + ΔV_temp, where ΔV_temp is a negative offset based on temperature. This dynamic adjustment effectively balances safety and power utilization. The manual mode allows users to select multiple preset parameter configuration files (e.g., "performance priority", "battery life priority", "high-altitude cold mode") in the Flash memory via the ground station or remote controller. After the MCU parses the instructions, it switches to the corresponding configuration to meet the needs of specific scenarios.

[0021] The fault diagnosis and recording function enables refined fault management. It can distinguish between instantaneous faults (such as current spikes lasting <10ms, which are recorded but not protected) and continuous faults (such as parameters exceeding the threshold for >100ms, which immediately trigger protection). It utilizes an external SPIFlash as a black box to record fault codes, timestamps, and key data curves before and after the fault, providing support for post-fault analysis. The MCU incorporates a temperature control model based on a Bayesian network algorithm to address the challenge of inaccurate estimation of battery SOX parameters (such as SOC and SOH) at ultra-low temperatures. This network uses ambient temperature, load current, and measured voltage as observational evidence, and employs probabilistic reasoning (such as P(SOC|Evidence)∝) to... P(Evidence|SOC)*P(SOC)) updates the posterior probability distribution of latent variables such as SOC and SOH, thereby providing the most likely state estimate in probabilistic form and dynamically optimizing protection parameters accordingly. For example, when the posterior probability of SOH indicates that the battery has aged significantly, the overcurrent protection threshold is automatically reduced. The MCU also implements an active self-balancing function through a high-precision BMS algorithm. It periodically scans the voltage of all cells, and when the maximum and minimum voltage difference exceeds a set threshold (such as 10mV), it controls the switch matrix to perform a flying capacitor active balancing, transferring charge from the high-voltage cells to the low-voltage cells. This process continues until the voltage is balanced, effectively delaying the performance degradation caused by battery pack inconsistency.

[0022] The fast response execution module is connected to the microprocessor unit and is used to control the on / off state of the main circuit according to the protection signal. The fast response execution module includes: a power switch circuit, which uses a low on-resistance N-MOSFET as an electronic switch; and a gate driver chip, which is used to amplify the protection signal of the microprocessor to quickly control the on / off state of the MOSFET.

[0023] The fast-response execution module employs low on-resistance (Rds(on) < 1mΩ level) N-channel MOSFETs (N-MOSFETs). To handle the potentially high currents (tens of amperes continuously, hundreds of amperes peaking) of drones, multiple MOSFETs are typically connected in parallel to further reduce the total on-resistance and distribute heat loss. The layout strictly ensures a short and wide high-current path, supplemented by heat sinks or large-area PCB copper plating for effective heat dissipation. The gate driver chip (such as the UCC27517) converts the 3.3V, milliampere-level GPIO control signal from the microprocessor into a 10V-15V gate voltage signal with ampere-level drive capability, sufficient to fully turn the MOSFETs on and off. The powerful push-pull output stage inside the driver chip can control the M... The gate capacitance of the OSFET is rapidly charged and discharged, thereby compressing the switching time (including turn-on delay, rise time, turn-off delay, and fall time). This not only significantly reduces switching losses, but more importantly, it enables extremely fast response to protection signals. The overall protection action (from the MCU sending a signal to the main circuit being completely shut down) can be completed within a few microseconds, which is sufficient to cope with severe instantaneous overcurrent or short-circuit impacts. In order to ensure the stability of the drive and the safety of the MOSFET, a small gate resistor (such as 10Ω) is usually connected in series between the output of the driver chip and the gate of the MOSFET to suppress possible oscillations in the gate circuit, and a Zener diode (such as 18V) is connected in parallel between the gate and source of the MOSFET for clamping to prevent device damage caused by gate overvoltage or parasitic conduction.

[0024] The high-reliability power supply module is electrically connected to the multi-parameter high-precision detection network, microprocessor unit, and fast-response execution module. It provides a stable operating voltage for these components. The high-reliability power supply module employs an architecture combining a charge pump circuit and a low-dropout linear regulator to provide stable low-voltage power to the microprocessor and sensors. The output of the high-reliability power supply module also features a compatibility interface that supports various UAV power interface standards and communication protocols, which can be adapted via jumper caps or software configuration.

[0025] The high-reliability power supply module employs a cascaded architecture combining a charge pump switching regulator and a low-dropout linear regulator (LDO) to achieve both high efficiency and low noise. The first stage uses a high-voltage charge pump circuit (such as the LM5004) to efficiently step down the potentially high voltage of the drone battery pack (e.g., 50.4V for a fully charged 12S lithium battery) to an intermediate voltage (e.g., 12V). The second stage uses a high-performance LDO (such as the TPS7A47) to convert the 12V intermediate voltage to the required 3.3V (powering the microprocessor, reference voltage source, and digital logic circuits) and 5V (powering the gate driver chip and communication transceiver). The LDO provides a stable output voltage with extremely low noise and high power supply rejection ratio (PSRR). At the output, the module features a highly flexible compatibility interface, physically providing a standard power connection. The connector (such as XT60) has reserved multiple sets of functional pins (power, ground, CAN_H / L, UART_TX / RX, etc.). In terms of configuration, it supports hardware jumper selection (such as enabling the terminating resistor and selecting the interface type) and software configuration (such as receiving configuration commands via UART at power-on to set the CAN bus baud rate, device address, etc.). This allows it to seamlessly adapt to the power interface standards (such as different plug types and pin definitions) and communication protocols (such as common parameters of open-source flight controllers such as PX4 and ArduPilot) of different manufacturers' UAV platforms. This greatly improves the versatility and integration convenience of the protection circuit, ensuring that the protection circuit itself can still provide a quiet and stable working environment for sensitive signal chains and digital cores when facing voltage fluctuations and noise interference on the UAV power bus.

[0026] In this application, the multi-mode intelligent protection circuit consists of four functional modules: a multi-parameter high-precision detection network, a microprocessor unit, a fast response execution module, and a high-reliability power supply module. These four modules cooperate with each other to form a closed-loop intelligent protection system.

[0027] A multi-parameter high-precision detection network collects real-time data on the voltage (V_bus), current (I_bus), and temperature (T_batt, T_power) of critical components on the power bus (typically the output of the UAV battery pack). These analog or digital signals are fed into a microprocessor unit. The microprocessor unit runs a built-in multi-mode protection logic algorithm to analyze, calculate, and judge the detection data. The algorithm integrates information such as the current flight mode, ambient temperature, and historical data to dynamically calculate or select applicable protection thresholds (overvoltage OVP, undervoltage UVP, overcurrent OCP). Once the detected parameters exceed the safety threshold, or the fault diagnosis logic determines an anomaly, the microprocessor unit immediately generates a protection control signal. The fast-response execution module receives the protection control signal from the microprocessor and quickly cuts off or restores the electronic switch (MOSFET) of the main power circuit through the gate drive circuit to control the power output. The high-reliability power supply module draws power directly from the UAV power bus and, through efficient and stable voltage conversion, provides the required clean DC operating power of different voltage levels to the detection network, microprocessor, and gate drive circuit.

[0028] This application constructs a collaborative system integrating a multi-parameter high-precision detection network, a microprocessor intelligent decision-making unit, a fast-response execution module, and a high-reliability power supply module. This system comprehensively enhances the adaptability and reliability of UAV power supplies under complex flight conditions. The system can dynamically adjust protection thresholds such as overcurrent, overvoltage, and undervoltage based on real-time flight modes, ambient temperature, and load changes, effectively avoiding the malfunctions or protection lag issues of traditional fixed-threshold protection under extreme conditions. Combined with a temperature control model based on Bayesian network algorithms and a graphene heating film active temperature control system, the system significantly enhances the accurate monitoring and rapid self-recovery capabilities of the power supply status in ultra-low temperature environments, ensuring stable operation under extremely cold conditions. At the same time, through the cascaded power supply design of charge pumps and low-dropout linear regulators at the hardware level, a fast-response switching circuit with multiple MOSFETs in parallel, and fault diagnosis and black box recording functions at the software level, the system's anti-interference capability, response speed, and maintainability are further improved. Ultimately, this circuit realizes the leap from "passive response" to "active adaptation" in UAV power supply protection, providing highly reliable energy security for scenarios such as high-altitude and cold-region inspection, logistics transportation, and emergency rescue.

[0029] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A multi-mode intelligent protection circuit for a drone power supply, characterized in that, include: A multi-parameter high-precision detection network is used to collect voltage, current and temperature information of the power bus in real time. A microprocessor unit, which is connected to the multi-parameter high-precision detection network, is used to execute a multi-mode protection logic algorithm based on the detection data. A fast response execution module is connected to the microprocessor unit and is used to control the on / off state of the main circuit according to the protection signal. A high-reliability power supply module is electrically connected to the multi-parameter high-precision detection network, the microprocessor unit, and the fast-response execution module. The high-reliability power supply module is used to provide a stable operating voltage for the multi-parameter high-precision detection network, the microprocessor unit, and the fast-response execution module.

2. The multi-mode intelligent protection circuit for UAV power supply according to claim 1, characterized in that, The multi-parameter high-precision detection network includes: A voltage sampling circuit, wherein the voltage sampling circuit uses a high-precision voltage divider resistor network and an analog-to-digital converter to acquire voltage signals; A current sampling circuit, wherein the current sampling circuit uses a precision sampling resistor and a differential amplifier or a Hall effect current sensor to achieve current measurement; A temperature sampling circuit is provided, wherein a negative temperature coefficient thermistor is arranged at the interface between the power device and the battery.

3. The multi-mode intelligent protection circuit for UAV power supply according to claim 1, characterized in that, The microprocessor unit has built-in multi-mode protection logic, which includes automatic mode, manual mode and fault diagnosis and recording function. The automatic mode dynamically adjusts the protection thresholds for overcurrent, overvoltage and undervoltage according to real-time flight data and ambient temperature. The manual mode selects a preset protection strategy through ground station or remote controller commands. The fault diagnosis and recording function is used to distinguish fault types and record fault data.

4. The multi-mode intelligent protection circuit for UAV power supply according to claim 1, characterized in that, The fast response execution module includes: A power switching circuit, wherein the power switching circuit uses an N-MOSFET with low on-resistance as an electronic switch; A gate driver chip, which is used to amplify the protection signal of the microprocessor to quickly control the switching on and off of the MOSFET.

5. A multi-mode intelligent protection circuit for a drone power supply according to claim 1, characterized in that, The high-reliability power supply module adopts an architecture that combines a charge pump circuit with a low-dropout linear regulator to provide stable low-voltage power supply for the microprocessor and sensors.

6. A multi-mode intelligent protection circuit for a drone power supply according to claim 1, characterized in that, The output of the high-reliability power supply module is also designed with a compatibility interface, which supports multiple UAV power interface standards and communication protocols and can be adapted through jumper caps or software configuration.

7. A multi-mode intelligent protection circuit for a drone power supply according to claim 3, characterized in that, The multi-mode protection logic also includes a temperature control model based on a Bayesian network algorithm, which is used to achieve accurate detection and dynamic adjustment of SOX parameters in ultra-low temperature environments.

8. A multi-mode intelligent protection circuit for a drone power supply according to claim 1, characterized in that, The multi-parameter high-precision detection network integrates a graphene heating film and a heat spreader. The graphene heating film and heat spreader are used to quickly increase the battery temperature in low-temperature environments, ensuring that the power system can work normally in low-temperature environments.

9. A multi-mode intelligent protection circuit for a drone power supply according to claim 1, characterized in that, The microprocessor unit is also equipped with an active self-balancing function, which uses a high-precision BMS algorithm to achieve precise equalization control of the energy of multiple battery cells.

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