An unmanned aerial vehicle power supply voltage stabilization control method and system based on LC multi-stage filtering

Abstract

The application discloses a kind of based on LC multistage filter's unmanned aerial vehicle power supply voltage stabilizing control method and system, including power supply interface module;Multistage LC filter module is electrically connected with power supply interface module, for output filtered voltage;Voltage stabilizing module is electrically connected with multistage LC filter module output end, for connecting unmanned aerial vehicle load;Detection module is used to collect output voltage, current and temperature parameter;Control module is electrically connected with detection module, multistage LC filter module and voltage stabilizing module respectively;Multistage LC filter module includes at least two groups of filter branch, and each filter branch is formed by at least two levels of inductance and capacitor filter unit composition;Selective access is carried out between each filter branch by switching unit, so that multistage LC filter module forms the filter path of different equivalent impedance characteristics;Control module is used to adjust the working parameter of voltage stabilizing module, and the separation inhibition of high frequency and low frequency interference can be effectively realized.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) power supply technology, and in particular to a UAV power supply voltage regulation control method and system based on LC multi-stage filtering. Background Technology

[0002] During flight missions, UAVs face typical conditions of drastic load fluctuations in their power supply systems. Sensitive loads such as flight control, image transmission, and GPS require high-purity, stable power, while high-power loads like motors and servos experience millisecond-level current surges during rapid acceleration or braking. Existing UAV power supply solutions typically employ a series structure of "fixed-parameter LC filter + voltage regulator module." The core problem with this is that the impedance characteristics of the filter network, once determined, cannot be changed. When the load current jumps from hundreds of milliamps to tens of amperes, the fixed filter path either suffers from excessive series impedance leading to severe voltage drops under high-current conditions, or insufficient filtering depth results in high-frequency ripple contamination of sensitive loads under low-current conditions. Both scenarios can trigger flight control resets, image transmission snow, or motor synchronism failure. Therefore, enabling the power supply system to adaptively adjust filtering and voltage regulation strategies based on real-time load conditions has become a pressing technical problem in the field of UAV power supply control. Summary of the Invention

[0003] To overcome the shortcomings of existing technologies, this invention provides a method and system for power supply regulation and control of unmanned aerial vehicles based on LC multi-stage filtering.

[0004] The technical solution adopted by this invention to solve its technical problem is: This invention provides a power supply voltage regulation control system for unmanned aerial vehicles (UAVs) based on LC multi-stage filtering, comprising: Power supply interface module; The multi-stage LC filter module has its input terminal electrically connected to the power supply interface module, and its output terminal is used to output the filtered voltage. The voltage regulator module has its input terminal electrically connected to the output terminal of the multi-stage LC filter module, and its output terminal is used to connect to the UAV load. The detection module, located at the output of the voltage regulator module, is used to collect output voltage, current, and temperature parameters. The control module is electrically connected to the detection module, the multi-stage LC filter module, and the voltage regulator module, respectively. The multi-stage LC filter module includes at least two sets of filter branches, and each filter branch consists of at least two filter units composed of inductors and capacitors. Each filter branch is selectively connected through a switching unit, so that the multi-stage LC filter module forms filter paths with different equivalent impedance characteristics. The control module controls the connection status of the filter branch based on the parameters collected by the detection module, and adjusts the operating parameters of the voltage regulator module.

[0005] Preferably, the filter unit constitutes a π-type or T-type filter structure. Each stage of the filter unit includes an input capacitor and an output capacitor located on both sides of the inductor element. The input capacitor and the output capacitor are both connected in parallel to ground. The topologies of different stages of the filter unit are different. Each stage of the filter unit adopts a cascaded connection method, and the inductance value of each stage of the inductor element decreases step by step along the power transmission direction, while the capacitance value of each stage of the capacitor element increases step by step, so that the cutoff frequency of each stage of the filter unit is distributed according to a preset frequency range. At least two sets of filter units are divided by frequency response range, one set of filter units corresponds to the high-frequency suppression range, and the other set of filter units corresponds to the low-frequency suppression range. The π-type or T-type structure is combined with the cascaded method of gradually decreasing inductance and gradually increasing capacitance. At the same time, different topologies are set for different stages of the filter unit, and the different filter units are assigned to the high-frequency suppression range and the low-frequency suppression range according to the frequency response range. This can achieve broadband ripple suppression from high frequency to low frequency in the same filter path, avoiding the problem that a single topology is insufficient for suppressing specific frequency bands. At the same time, the non-uniform inter-stage topology design destroys the resonance peak caused by parasitic parameters, significantly reducing spike noise and low-frequency fluctuations on the power line.

[0006] Preferably, the filter unit constitutes a π-type or T-type filter structure. Each stage of the filter unit includes an input capacitor and an output capacitor located on both sides of the inductor element. The input capacitor and the output capacitor are connected in parallel to ground. The topology of different stages of the filter unit is the same. Each stage of the filter unit adopts a cascaded connection method, and the inductance value of each stage of the inductor element decreases step by step along the power transmission direction, while the capacitance value of each stage of the capacitor element increases step by step, so that the cutoff frequency of each stage of the filter unit is distributed according to a preset frequency range. At least two sets of filter units are divided by frequency response range, one set of filter units corresponds to the high-frequency suppression range, and the other set of filter units corresponds to the low-frequency suppression range. The topology of each stage of the filter unit is kept consistent, simplifying the inter-stage matching complexity. At the same time, the parameter gradient of gradually decreasing inductance and gradually increasing capacitance, as well as the method of dividing the filter unit according to frequency range, are still used to make the high-frequency suppression unit and the low-frequency suppression unit each undertake a clear filtering task. Under the premise of ensuring filtering performance, the design and debugging difficulty is reduced, and the additional impedance discontinuities introduced by frequent topology changes are avoided, so that high-frequency and low-frequency ripples are absorbed in a regional and efficient manner. It is particularly suitable for mixed frequency band interference scenarios caused by frequent load jumps in the power supply line of UAVs.

[0007] Preferably, the switching unit includes semiconductor switching devices respectively disposed at the input or output terminals of each level of the filter unit. These devices are used to selectively connect or bypass the corresponding filter unit, or to switch or connect in parallel between different filter branches. The semiconductor switching devices independently control the on / off states at the input or output terminals of each level of the filter unit, enabling selective connection, bypass, inter-group switching, or parallel combination of filter units. The resulting technical advantages are: dynamic reconstruction of the filter network topology without power loss or system restart; rapid matching of the most suitable filter unit combination based on real-time interference frequency bands; and avoidance of delays and contact bounce problems associated with mechanical switches, significantly improving the response speed and switching lifespan of the filter configuration.

[0008] Preferably, the control module controls the switching unit to form at least two different levels of filter path structure and switches between different filter path structures. Different filter path structures correspond to different equivalent impedance characteristics. By driving the switching unit through the control module, the filter network can be configured into at least two different levels of path structure. Each structure corresponds to its own equivalent impedance characteristics, and the switching between paths is based on the operating conditions to achieve a dynamic balance between filtering depth and voltage drop. That is, when the load current is small, the higher-order filter path is switched to pursue ultimate ripple suppression, and when the load current suddenly increases, the lower-order filter path is switched to reduce the voltage drop caused by series impedance, thereby taking into account both the power supply purity and dynamic load capacity of the UAV.

[0009] Preferably, the voltage regulator module includes a DC-DC converter circuit, which includes a switching transistor, an inductor energy storage unit, and an output capacitor unit. It also includes a feedback sampling circuit. The sampling node of the feedback sampling circuit and the output node of the multi-stage LC filter module are the same electrical node or an equivalent electrical node. By setting the feedback sampling node of the DC-DC converter circuit and the output node of the multi-stage LC filter module to the same electrical node or an equivalent electrical node, the voltage regulator module can directly sense the actual voltage waveform after LC filtering. This avoids control errors introduced due to line voltage drop or secondary coupling noise between the sampling point and the filter output point, thereby improving the accuracy and phase margin of the closed-loop regulation and effectively suppressing the reverse pollution of the preceding filter network by the switching action of the voltage regulator module itself.

[0010] Preferably, the detection module includes: a voltage sampling circuit composed of voltage divider resistors; a current sampling circuit composed of series sampling resistors or Hall elements; and a temperature sensor located near the inductor or load. The voltage sampling circuit is connected to the feedback sampling node. The voltage is collected by the voltage divider resistors, the current is collected by the series sampling resistors or Hall elements, and the temperature sensor is collected by the temperature sensor. The voltage sampling circuit is connected to the aforementioned feedback sampling node, which can synchronously acquire three-dimensional parameters of voltage, current, and temperature at the same electrical reference point, eliminating calculation deviations caused by inconsistent sampling references. At the same time, the temperature sensor is used to monitor the temperature rise of key hot spots, providing the original basis for subsequent control modules to perform thermal compensation or derating protection, and preventing the filter inductor or voltage regulator module from overheating and failing.

[0011] Preferably, the control module includes a microcontroller unit. The microcontroller unit, based on voltage ripple amplitude, temperature change, and load current change, uses at least two parameter combinations as criteria to jointly adjust the switching of the filter path structure and the duty cycle or switching frequency of the voltage regulator module. The microcontroller unit simultaneously incorporates three parameters—voltage ripple amplitude, temperature change, and load current change—and employs at least two parameter combinations to jointly adjust the filter path switching and the duty cycle or switching frequency of the voltage regulator module. The resulting technical effect is that it avoids the "hesitation zone" phenomenon where a single criterion repeatedly switches or remains inactive under boundary conditions. It can automatically select the optimal filtering-voltage regulation coordinated strategy under different scenarios such as high temperature and high current versus low temperature and low current, significantly improving the system's adaptability and control stability to complex flight profiles.

[0012] Preferably, the multi-stage LC filter module is placed in the power supply cable path and encapsulated in a shielded housing. The inductor and voltage regulator module are placed on the same heat dissipation structure. The filter unit for suppressing high-frequency ripple is placed close to the load, and the filter unit for suppressing low-frequency fluctuations is placed close to the power supply interface module. By placing the multi-stage LC filter module in the power supply cable path and adding a shielded housing, the inductor and voltage regulator module share a heat dissipation structure. At the same time, the high-frequency suppression unit is close to the load, and the low-frequency suppression unit is close to the power supply interface. The shielded housing blocks the external radiation of the filter network and the electromagnetic interference from the outside world to the filter network. The shared heat dissipation structure ensures uniform temperature distribution of the heat-generating components and avoids local hot spots. The high-frequency unit being close to the load can shorten the conduction path of high-frequency noise, and the low-frequency unit being close to the power supply interface can use the line impedance to help attenuate low-frequency fluctuations. This improves the engineering feasibility of the system in the compact space of the UAV from the two dimensions of electromagnetic compatibility and thermal management.

[0013] A voltage regulation control method for UAV power supply based on LC multi-stage filtering includes the following steps: S1: Construct an LC filter network containing multiple filter branches, and form different filter paths through switching units; S2: Select the filter branch corresponding to the frequency suppression range based on the output voltage ripple and load changes; S3: Obtain the feedback signal at the filter output node and input it into the voltage regulator module; S4: By adjusting the operating parameters of the voltage regulator module and the connection status of the filter branch, stable output voltage control is achieved. First, a multi-branch reconfigurable LC filter network is constructed. Then, based on the output voltage ripple and load changes, the filter branch corresponding to the frequency suppression range is actively matched. Then, the feedback signal of the filter output node is introduced into the voltage regulator module. Finally, the parameters of the voltage regulator module and the status of the filter branch are jointly adjusted. Ultimately, a closed-loop control process of "ripple detection → frequency band identification → branch matching → voltage regulation coordination" is formed, so that the filtering link and the voltage regulation link no longer work independently but respond in coordination. It is especially suitable for UAVs to quickly switch between different modes such as hovering, climbing, and diving, and the dynamic overshoot and recovery time of the output voltage are controlled to less than half of the traditional independent solution.

[0014] The beneficial effects of this invention are: 1. By setting up multiple filtering units and dividing the frequency range, the separation and suppression of high-frequency and low-frequency interference can be achieved; 2. By constructing a reconfigurable filtering path through switching units, the system's ability to adapt to different load changes is improved; 3. By coupling the filter output node with the feedback node of the voltage regulator module, the voltage control accuracy is improved; 4. Improve system stability and reduce battery heat generation through multi-parameter joint adjustment. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. The accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Figure 1 This is a structural block diagram of the power supply and voltage regulation control system of the present invention; Figure 2 This is a schematic diagram of the structure of the T-type LC filter unit of the present invention; Figure 3 This is a schematic diagram of the structure of the π-type LC filter unit of the present invention; Figure 4 This is one of the block diagrams of the multi-filter branch switching structure of the present invention; Figure 5 This is the second block diagram of the multi-filter branch switching structure of the present invention; Figure 6 This is the third block diagram of the multi-filter branch switching structure of the present invention; Figure 7 This is the control flowchart of the power supply voltage regulation control system of the present invention. Detailed Implementation

[0018] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0019] In the description of this application, terms such as "first" and "second" are used only to distinguish different objects, not to describe a specific order. Furthermore, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Additionally, "at least one" refers to one or more, and "multiple" refers to two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can represent: a, b, c; a and b; a and c; b and c; or a and b and c. Where a, b, and c can be single or multiple.

[0020] The terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0021] In this application, the words "exemplary" or "for example" are used to indicate that something is an example, illustration, or illustration. Any embodiment or design described as "exemplary," "for example," or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Rather, the use of the words "exemplary," "for example," or "for example" is intended to present the relevant concepts in a specific manner.

[0022] It is understood that in this application, "when," "if," and "if" all refer to the device making a corresponding action under certain objective circumstances, and are not time-limited, nor do they require the device to make a judgment action when it is implemented, nor do they imply any other limitations.

[0023] In this application, the use of singular designations for elements is intended to represent "one or more" rather than "one and only one," unless otherwise specified.

[0024] It is understood that in the embodiments of this application, "B corresponding to A" means that there is a correspondence between A and B, and B can be determined based on A. Determining B based on A does not mean that B can be determined solely based on A; B can also be determined based on A and / or other information.

[0025] Reference Figures 1 to 7 A power supply voltage regulation control system for unmanned aerial vehicles based on LC multi-stage filtering includes: Power supply interface module; The multi-stage LC filter module has its input terminal electrically connected to the power supply interface module, and its output terminal is used to output the filtered voltage. The voltage regulator module has its input terminal electrically connected to the output terminal of the multi-stage LC filter module, and its output terminal is used to connect to the UAV load. The detection module, located at the output of the voltage regulator module, is used to collect output voltage, current, and temperature parameters. The control module is electrically connected to the detection module, the multi-stage LC filter module, and the voltage regulator module, respectively. The multi-stage LC filter module includes at least two sets of filter branches, and each filter branch consists of at least two filter units composed of inductors and capacitors. Each filter branch is selectively connected through a switching unit, so that the multi-stage LC filter module forms filter paths with different equivalent impedance characteristics. The control module controls the connection status of the filter branch based on the parameters collected by the detection module, and adjusts the operating parameters of the voltage regulator module.

[0026] The drone payload includes lighting or image transmission. The parameters of each LC filter unit are designed according to the cutoff frequency. The cutoff frequency of the upper-level filter unit is higher than that of the lower-level filter unit, so as to achieve layered filtering of noise in different frequency bands.

[0027] The control module divides the interference signal into high-frequency interference components and low-frequency interference components based on the frequency characteristics of the sampled signal. The high-frequency interference components correspond to the frequency band above the preset cutoff frequency, while the low-frequency interference components correspond to the frequency band below the preset cutoff frequency.

[0028] In use, the power supply interface module is set as the energy input, and at least two sets of filter branches in the multi-stage LC filter module (each branch consists of at least two stages of filter units composed of inductors and capacitors) are used in conjunction with the switching unit to achieve selective access. This allows the multi-stage LC filter module to form filter paths with different equivalent impedance characteristics according to actual operating conditions. This dynamically adjusts the filter strength to address ripple and interference of different frequency bands and amplitudes during UAV power supply, significantly reducing the output voltage ripple coefficient and high-frequency noise, and improving power supply purity. Based on this, the voltage regulator module performs secondary regulation on the filtered voltage, and the detection... The module collects the voltage, current, and temperature parameters at the output of the voltage regulator module in real time. Based on these parameters, the control module simultaneously controls the connection status of the filter branch and adjusts the operating parameters of the voltage regulator module, forming a closed-loop control. Its technical effect is that it can quickly match the optimal filtering and voltage regulation combination strategy when there are sudden load changes, temperature changes, or battery voltage fluctuations, avoiding the problems of response lag or insufficient filtering under the traditional fixed filtering structure. This ensures the stability of the UAV load voltage and the dynamic response speed, while reducing the additional power consumption and heat generation caused by the mismatch between filtering and voltage regulation, and improving the reliability and endurance of the system under complex flight conditions.

[0029] By setting up a multi-stage inductor-capacitor combined filter network between the ground power supply and the drone payload, and constructing a π-type or cascaded filter topology, high-frequency ripple and transient interference in the input voltage are suppressed in stages. Simultaneously, a voltage regulator module precisely controls the output voltage, keeping the power supply voltage within a safe range. The system can monitor the output ripple amplitude, temperature rise, and load fluctuations in real time, and optimize filter parameters or switch operating modes through a feedback adjustment mechanism. This reduces the risk of heat generation and degradation of the energy storage battery due to voltage fluctuations, and avoids flickering or overload in the LED driver circuit. This solution can extend battery cycle life, improve the stability of the lighting system, and is suitable for long-term continuous operation scenarios, showing broad application prospects in emergency equipment, power inspection, and mobile power supply.

[0030] Specifically, the filter unit constitutes a π-type or T-type filter structure. Each stage of the filter unit includes an input capacitor and an output capacitor located on both sides of the inductor element. Both the input and output capacitors are connected in parallel to ground. The topology of different stages of the filter unit is the same. Each stage of the filter unit adopts a cascaded connection method, and the inductance value of each stage of the inductor element decreases step by step along the power transmission direction, while the capacitance value of each stage of the capacitor element increases step by step, so that the cutoff frequency of each stage of the filter unit is distributed according to a preset frequency range. At least two sets of filter units are divided by frequency response range, one set of filter units corresponds to the high-frequency suppression range, and the other set of filter units corresponds to the low-frequency suppression range. The topology of each stage of the filter unit is kept consistent, simplifying the inter-stage matching complexity. At the same time, the parameter gradient of gradually decreasing inductance and gradually increasing capacitance, as well as the method of dividing the filter unit according to frequency range, are still used to make the high-frequency suppression unit and the low-frequency suppression unit each undertake a clear filtering task. While ensuring filtering performance, the design and debugging difficulty is reduced, and the additional impedance discontinuities introduced by frequent topology changes are avoided, so that high-frequency and low-frequency ripples are absorbed in a regional and efficient manner. It is particularly suitable for mixed frequency band interference scenarios caused by frequent load jumps in the power supply line of UAVs.

[0031] The frequency response interval division is based on the equivalent frequency band discrimination based on the rate of change and amplitude characteristics of the output voltage ripple signal. The control module performs discrimination or equivalent frequency domain analysis based on the rate of change and amplitude characteristics of the sampled signal. According to the dominant frequency components, the ripple is divided into high-frequency intervals and low-frequency intervals, and the corresponding filter branches are selected accordingly.

[0032] Specifically, the switching unit includes semiconductor switching devices respectively disposed at the input or output terminals of each level of the filter unit. These devices are used to selectively connect or bypass the corresponding filter unit, or to switch or connect in parallel between different filter branches. The semiconductor switching devices independently control the on / off states at the input or output terminals of each level of the filter unit, enabling selective connection, bypassing, inter-group switching, or parallel combination of filter units. The resulting technical advantages are: dynamic reconstruction of the filter network topology without power loss or system restart; rapid matching of the most suitable filter unit combination based on real-time interference frequency bands; and avoidance of delays and contact bounce problems associated with mechanical switches, significantly improving the response speed and switching lifespan of the filter configuration.

[0033] Specifically, the control module controls the switching unit to form at least two different levels of filter path structure and switches between different filter path structures. Different filter path structures correspond to different equivalent impedance characteristics. By driving the switching unit through the control module, the filter network can be configured into at least two different levels of path structure. Each structure corresponds to its own equivalent impedance characteristics, and the switching between paths is based on the operating conditions to achieve a dynamic balance between filtering depth and voltage drop. That is, when the load current is small, it switches to a higher-order filter path to pursue ultimate ripple suppression, and when the load current suddenly increases, it switches to a lower-order filter path to reduce the voltage drop caused by series impedance, thereby taking into account both the power supply purity and dynamic load capacity of the UAV.

[0034] The control module performs derating control on the filter branch or voltage regulator module based on temperature parameters. During the switching process of the filter branch, the control module gradually adjusts the duty cycle of the switching device to achieve a smooth transition of the filter branch, thereby reducing voltage surges and current jumps during the switching process.

[0035] It is worth noting that the "switching to a lower-order filter path when the load current suddenly increases" in this solution does not lower the filtering standard of the entire power supply system. Instead, it optimizes the impedance of the high-power load branch. Sensitive loads (flight controller, sensors, image transmission) are always powered through the high-frequency suppression branch, and their ripple level is not affected by the switching of the motor branch. Even if the inductor impedance in the high-order filter path is relatively large (e.g., 50mΩ) at low current, if the current is only 0.5A, then the conduction loss = I 2 R=0.5 2 ×0.05 = 0.0125W, which is negligible. At this point, the system prioritizes extremely low ripple (e.g., reducing from 50mV to 5mV) because low-current loads (such as flight controllers and sensors) require extremely high voltage purity. However, if high-order filtering is still used at high currents, with the same 50mΩ and a current of 10A, the loss = 10. 2 ×0.05 = 5W, which will lead to significant heat generation and efficiency loss. At this point, it is necessary to switch to a lower-order path. Although the ripple may rise to 30mV, it is acceptable, as shown in the table below: Specifically, the voltage regulator module includes a DC-DC converter circuit, which comprises a switching transistor, an inductor energy storage unit, and an output capacitor unit. It also includes a feedback sampling circuit. The sampling node of this feedback sampling circuit is the same electrical node or an equivalent electrical node as the output node of the multi-stage LC filter module. By setting the feedback sampling node of the DC-DC converter circuit and the output node of the multi-stage LC filter module to the same electrical node or equivalent electrical node, the voltage regulator module can directly sense the actual voltage waveform after LC filtering. This avoids control errors introduced due to line voltage drop or secondary coupling noise between the sampling point and the filter output point, thereby improving the accuracy and phase margin of the closed-loop regulation and effectively suppressing the reverse pollution of the preceding filter network by the switching action of the voltage regulator module itself.

[0036] The DC-DC converter circuit can be any one of buck, boost, buck-boost, or a combination thereof. To ensure system stability, the filter module and the voltage regulator module are isolated by a buffer network. The buffer network is used to reduce the phase influence of the filter module on the voltage regulator control loop. The control bandwidth of the control module on the voltage regulator module is lower than the response frequency of the filter module to avoid oscillation caused by loop coupling.

[0037] Specifically, the detection module includes: a voltage sampling circuit composed of voltage divider resistors; a current sampling circuit composed of series sampling resistors or Hall elements; and a temperature sensor located near the inductor or load. The voltage sampling circuit is connected to the feedback sampling node. It uses voltage divider resistors to collect voltage, series sampling resistors or Hall elements to collect current, and temperature sensors to collect inductor or load temperature. By connecting the voltage sampling circuit to the aforementioned feedback sampling node, it can synchronously acquire three-dimensional parameters of voltage, current, and temperature at the same electrical reference point, eliminating calculation deviations caused by inconsistent sampling references. At the same time, the temperature sensor monitors the temperature rise of key hot spots, providing the original basis for subsequent control modules to perform thermal compensation or derating protection, and preventing the filter inductor or voltage regulator module from overheating and failing.

[0038] The temperature sensor can be a thermistor, thermocouple, or integrated temperature sensing chip; no specific model of temperature sensor is specified here.

[0039] Specifically, the control module includes a microcontroller unit. Based on voltage ripple amplitude, temperature change, and load current change, the microcontroller unit jointly adjusts the switching of the filter path structure and the duty cycle or switching frequency of the voltage regulator module using at least two parameter combinations. The microcontroller unit simultaneously incorporates three parameters—voltage ripple amplitude, temperature change, and load current change—and employs at least two parameter combinations to jointly adjust the filter path switching and the duty cycle or switching frequency of the voltage regulator module. The resulting technical effect is that it avoids the "hesitation zone" phenomenon where a single criterion repeatedly switches or remains inactive under boundary conditions. It can automatically select the optimal filtering-voltage regulation coordinated strategy under different scenarios such as high temperature and high current versus low temperature and low current, significantly improving the system's adaptability and control stability to complex flight profiles.

[0040] Criteria for parameter combination include, but are not limited to: When the voltage ripple amplitude is greater than the first threshold and the load current is less than the second threshold, the control module selects a higher-order filtering path. When the load current exceeds the third threshold or the temperature exceeds the fourth threshold, the control module switches to a low-order filtering path; each threshold can be adaptively adjusted based on system calibration or historical operating data.

[0041] The control module is used to coordinate the connection status of the filter branch and the operating parameters of the voltage regulator module, so that the changes in the impedance characteristics of the filter network match the dynamic response of the voltage regulator module.

[0042] The switching unit is also used to bypass part of the filter unit to reduce the equivalent series impedance under high current conditions.

[0043] Specifically, the multi-stage LC filter module is placed in the power cable path and encapsulated in a shielded housing. The inductor and voltage regulator module are placed on the same heat dissipation structure. The filter unit for suppressing high-frequency ripple is placed near the load, while the filter unit for suppressing low-frequency fluctuations is placed near the power interface module. By placing the multi-stage LC filter module in the power cable path and adding a shielded housing, and by sharing a heat dissipation structure with the inductor and voltage regulator module, the high-frequency suppression unit is placed near the load, and the low-frequency suppression unit is placed near the power interface. The shielded housing blocks the external radiation of the filter network and the electromagnetic interference from the outside world to the filter network. The shared heat dissipation structure ensures uniform temperature distribution of the heat-generating components and avoids local hot spots. The high-frequency unit being close to the load can shorten the conduction path of high-frequency noise, and the low-frequency unit being close to the power interface can utilize the line impedance to help attenuate low-frequency fluctuations. This improves the engineering feasibility of the system in the compact space of the UAV from the two dimensions of electromagnetic compatibility and thermal management.

[0044] A voltage regulation control method for UAV power supply based on LC multi-stage filtering includes the following steps: S1: Construct an LC filter network containing multiple filter branches, and form different filter paths through switching units; S2: Select the filter branch corresponding to the frequency suppression range based on the output voltage ripple and load changes; S3: Obtain the feedback signal at the filter output node and input it into the voltage regulator module; S4: By adjusting the operating parameters of the voltage regulator module and the connection status of the filter branch, stable output voltage control is achieved. First, a multi-branch reconfigurable LC filter network is constructed. Then, based on the output voltage ripple and load changes, the filter branch corresponding to the frequency suppression range is actively matched. Then, the feedback signal of the filter output node is introduced into the voltage regulator module. Finally, the parameters of the voltage regulator module and the status of the filter branch are jointly adjusted. Ultimately, a closed-loop control process of "ripple detection → frequency band identification → branch matching → voltage regulation coordination" is formed, so that the filtering link and the voltage regulation link no longer work independently but respond in coordination. It is especially suitable for UAVs to quickly switch between different modes such as hovering, climbing, and diving, and the dynamic overshoot and recovery time of the output voltage are controlled to less than half of the traditional independent solution.

[0045] Example 2 A power supply voltage regulation control system for unmanned aerial vehicles based on LC multi-stage filtering includes: Power supply interface module; The multi-stage LC filter module has its input terminal electrically connected to the power supply interface module, and its output terminal is used to output the filtered voltage. The voltage regulator module has its input terminal electrically connected to the output terminal of the multi-stage LC filter module, and its output terminal is used to connect to the UAV load. The detection module, located at the output of the voltage regulator module, is used to collect output voltage, current, and temperature parameters. The control module is electrically connected to the detection module, the multi-stage LC filter module, and the voltage regulator module, respectively. The multi-stage LC filter module includes at least two sets of filter branches, and each filter branch consists of at least two filter units composed of inductors and capacitors. Each filter branch is selectively connected through a switching unit, so that the multi-stage LC filter module forms filter paths with different equivalent impedance characteristics. The control module controls the connection status of the filter branch based on the parameters collected by the detection module, and adjusts the operating parameters of the voltage regulator module.

[0046] Specifically, the filter unit constitutes a π-type or T-type filter structure. Each stage of the filter unit includes an input capacitor and an output capacitor located on both sides of the inductor element. Both the input and output capacitors are connected in parallel to ground. The topology of different stages of the filter unit is different (not shown in the attached figures of this embodiment). Each stage of the filter unit adopts a cascaded connection method, and the inductance value of each stage of the inductor element decreases step by step along the power transmission direction, while the capacitance value of each stage of the capacitor element increases step by step, so that the cutoff frequency of each stage of the filter unit is distributed according to a preset frequency range. At least two sets of filter units are divided by frequency response range, and one set of filter units corresponds to high frequency suppression. In the first interval, another set of filter units corresponds to the low-frequency suppression interval. It adopts a π-type or T-type structure and is cascaded with gradually decreasing inductance and gradually increasing capacitance. At the same time, different topologies are set for different stages of filter units. Then, according to the frequency response interval, different filter units are divided into high-frequency suppression intervals and low-frequency suppression intervals. This can achieve broadband ripple suppression from high frequency to low frequency within the same filter path, avoiding the problem that a single topology is insufficient for suppressing specific frequency bands. At the same time, the non-uniform interstage topology design destroys the resonance peak caused by parasitic parameters, significantly reducing spike noise and low-frequency fluctuations on the power line.

[0047] Specifically, at least some of the filter units in the multi-stage LC filter module are also equipped with a damping network in parallel. The damping network includes a resistor or an RC buffer branch, which is used to suppress the resonant peak in the filter circuit. The control module adjusts the connection state or damping coefficient of the damping network according to the voltage ripple spectrum characteristics or oscillation amplitude collected by the detection module. In this way, when parameter coupling or load change occurs in the multi-stage LC filter network, the resonant peak can be actively suppressed to avoid overshoot or oscillation of the output voltage, thereby improving the system stability and electromagnetic compatibility performance.

[0048] Specifically, the drone load is divided into at least two power supply areas, including a sensitive load area and a high-power load area. The sensitive load area is powered through a high-frequency suppression filter branch, while the high-power load area is powered through a low-impedance filter branch. The control module configures the filter path and performs voltage regulation control for different load areas. This effectively avoids the impact of high-power load switching on the power supply quality of the sensitive load, and improves power supply isolation and anti-interference capabilities.

[0049] Specifically, when switching filter branches, the control module controls the switching unit to turn on or off according to a preset slope or delay strategy, so that the filter path forms a transition state during the switching process. This is used to avoid voltage transients or current spikes caused by sudden changes in the filter structure, thereby improving the smoothness of system operation. The control module is also used to estimate the equivalent output impedance of the filter network in real time and match it with the dynamic output impedance of the voltage regulator module to improve the overall stability margin of the system.

[0050] Except for the difference in the topology between different levels of filter units, the other technical features of Embodiment 2 of this application are the same as those of Embodiment 1.

[0051] Example 3 A power supply voltage regulation control system for unmanned aerial vehicles based on LC multi-stage filtering has a structure that is basically the same as that in Embodiment 1, except that: The control module also includes a self-learning optimization unit, which is used to record the system's operating data under different load, battery voltage and temperature conditions, and establish a mapping relationship between filter path selection and voltage regulation parameters. The control module dynamically corrects the parameter combination criteria based on historical operating data, or directly outputs the optimal filtering path and voltage regulation control parameters by looking up a table. Specifically, the self-learning optimization unit is implemented in any of the following ways: adaptive update based on lookup table; parameter fitting based on simple machine learning model; or weight adjustment mechanism based on empirical rules.

[0052] The control strategy can be continuously optimized over time, allowing the system to gradually approach the optimal working state under different flight conditions, thereby further improving power supply stability and energy efficiency.

[0053] The above descriptions provide one or more embodiments in conjunction with specific details, but do not imply that the specific implementation of the present invention is limited to these descriptions. Any methods or structures that are similar to or identical to those of the present invention, or any technical deductions or substitutions made based on the concept of the present invention, should be considered within the scope of protection of the present invention.

Claims

1. A power supply voltage regulation control system for unmanned aerial vehicles based on LC multi-stage filtering, characterized in that, include: Power supply interface module; The multi-stage LC filter module has its input terminal electrically connected to the power supply interface module, and its output terminal is used to output the filtered voltage. The voltage regulator module has its input terminal electrically connected to the output terminal of the multi-stage LC filter module, and its output terminal is used to connect to the UAV load. The detection module, located at the output of the voltage regulator module, is used to collect output voltage, current, and temperature parameters. The control module is electrically connected to the detection module, the multi-stage LC filter module, and the voltage regulator module, respectively. The multi-stage LC filter module includes at least two sets of filter branches, and each filter branch consists of at least two filter units composed of inductors and capacitors. Each filter branch is selectively connected through a switching unit, so that the multi-stage LC filter module forms filter paths with different equivalent impedance characteristics. The control module controls the connection status of the filter branch based on the parameters collected by the detection module, and adjusts the operating parameters of the voltage regulator module.

2. A UAV power supply voltage regulation control system based on LC multi-stage filtering according to claim 1, characterized in that: The filter unit forms a π-type or T-type filter structure. Each filter unit includes an input capacitor and an output capacitor located on both sides of the inductor. The input capacitor and the output capacitor are connected to ground in parallel. The topology of different filter units is different. Each filter unit adopts a cascaded connection method. The inductance value of each inductor decreases step by step along the power transmission direction, and the capacitance value of each capacitor increases step by step, so that the cutoff frequency of each filter unit is distributed according to a preset frequency range. At least two sets of filter units are divided by frequency response range. One set of filter units corresponds to the high-frequency suppression range, and the other set of filter units corresponds to the low-frequency suppression range.

3. A UAV power supply voltage regulation control system based on LC multi-stage filtering according to claim 1, characterized in that: The filter units form a π-type or T-type filter structure. Each filter unit includes an input capacitor and an output capacitor located on both sides of the inductor. The input capacitor and the output capacitor are connected to ground in parallel. The topology of different filter units is the same. Each filter unit is cascaded. The inductance value of each inductor decreases gradually along the power transmission direction, and the capacitance value of each capacitor increases gradually, so that the cutoff frequency of each filter unit is distributed according to a preset frequency range. At least two sets of filter units are divided by frequency response range, one set of filter units corresponds to the high-frequency suppression range, and the other set of filter units corresponds to the low-frequency suppression range.

4. A UAV power supply voltage regulation control system based on LC multi-stage filtering according to claim 2 or 3, characterized in that: The switching unit includes semiconductor switching devices respectively disposed at the input or output of each stage of the filtering unit, for selectively connecting or bypassing the corresponding filtering unit, or for switching or connecting in parallel between different filtering branches.

5. A UAV power supply voltage regulation control system based on LC multi-stage filtering according to claim 4, characterized in that: The control module controls the switching unit to form at least two different levels of filter path structure and switches between different filter path structures, with different filter path structures corresponding to different equivalent impedance characteristics.

6. A UAV power supply voltage regulation control system based on LC multi-stage filtering according to claim 1, characterized in that: The voltage regulator module includes a DC-DC converter circuit, which includes a switching transistor, an inductor energy storage unit, and an output capacitor unit. It is also equipped with a feedback sampling circuit. The sampling node of the feedback sampling circuit and the output node of the multi-stage LC filter module are the same electrical node or an electrically equivalent node.

7. A UAV power supply voltage regulation control system based on LC multi-stage filtering according to claim 1 or 6, characterized in that: The detection module includes: a voltage sampling circuit composed of voltage divider resistors; a current sampling circuit composed of series sampling resistors or Hall elements; a temperature sensor placed near the inductive element or load; and the voltage sampling circuit connected to the feedback sampling node.

8. A UAV power supply voltage regulation control system based on LC multi-stage filtering according to claim 5 or 7, characterized in that: The control module includes a microcontroller unit. The microcontroller unit controls the switching of the filter path structure and the duty cycle or switching frequency of the voltage regulator module based on at least two parameter combination criteria, according to the voltage ripple amplitude, temperature change and load current change.

9. A UAV power supply voltage regulation control system based on LC multi-stage filtering according to claim 3, characterized in that: The multi-stage LC filter module is located in the power supply cable path and is encapsulated in a shielded housing. The inductor and voltage regulator module are located on the same heat dissipation structure. The filter unit for suppressing high-frequency ripple is located near the load, and the filter unit for suppressing low-frequency fluctuations is located near the power supply interface module.

10. A power supply voltage regulation control method for unmanned aerial vehicles based on LC multi-stage filtering, characterized in that, Includes the following steps: S1: Construct an LC filter network containing multiple filter branches, and form different filter paths through switching units; S2: Select the filter branch corresponding to the frequency suppression range based on the output voltage ripple and load changes; S3: Obtain the feedback signal at the filter output node and input it into the voltage regulator module; S4: The output voltage is stabilized by adjusting the operating parameters of the voltage regulator module and the connection status of the filter branch.

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