An AC impedance detection method and device for an unmanned aerial vehicle

Abstract

The present invention provides a method and device for detecting the AC impedance of an unmanned aerial vehicle (UAV). Without relying on additional hardware, it can reduce the cost of implementing the AC impedance detection of the UAV battery, and is easy to operate and implement. The method includes the following steps: controlling the UAV to perform vibration flight, where the vibration flight can cause a power change on the load side of the UAV's power system, thereby generating a vibration of an electrical signal, and the vibration of the electrical signal causes an AC perturbation signal to be generated on the battery side of the UAV; collecting the current and voltage data of the UAV battery during the vibration flight, and calculating the AC impedance of the UAV battery based on the collected current and voltage data.

Description

Technical Field

[0001] The present invention relates to the technical field of battery detection for unmanned aerial vehicles, and particularly relates to an AC impedance detection method and device for unmanned aerial vehicles. Background Art

[0002] As an electrochemical power source, a battery or fuel cell has an output characteristic in the form of an open-circuit voltage plus an internal impedance, as Figure 1 shown. Among them, the internal impedance is a complex non-linear impedance, and the impedance spectrum of the battery is as Figure 2 shown, with the horizontal axis being the real part and the vertical axis being the negative imaginary part. The value of the internal impedance of a battery or fuel cell is related to its internal state, so it can be used as a non-invasive detection technology. The main process of the AC impedance detection technology is as follows: at the output end of the battery or fuel cell, on the normal DC output current, a small AC perturbation signal is superimposed, and the frequency depends on the required spectral range. Then, the feedback voltage of the battery or fuel cell is detected, and the AC part is extracted. From the injected AC current and the feedback AC voltage signal, the AC impedance of the battery or fuel cell can be calculated, and then the state of the current power supply can be judged based on the obtained impedance information.

[0003] Traditionally, the AC impedance technology is generally used in laboratories, and a specific impedance detection device is used to generate the AC perturbation. Extra hardware devices are required, and the electrochemical workstation for testing the AC impedance of the battery is expensive and cannot be applied to online detection.

[0004] In some applications and academic research, power electronic devices connected to the battery and fuel cell, such as DC / DC converters, are also used to generate the AC perturbation, so as to realize the online AC impedance detection technology. This technology requires modifications to the powertrain system and cannot use traditional modular power electronic devices, resulting in high modification costs in actual applications. Summary of the Invention

[0005] In view of the above problems, the present invention provides an AC impedance detection method and device for unmanned aerial vehicles, which do not rely on extra hardware, can reduce the cost of realizing the AC impedance detection of unmanned aerial vehicle batteries, and are easy to operate and implement.

[0006] The technical solution is as follows: An AC impedance detection method for unmanned aerial vehicles includes the following steps:

[0007] Control the unmanned aerial vehicle to fly in a vibrating manner. The vibrating flight can cause a power change on the load side of the power system of the unmanned aerial vehicle, thereby generating a vibration of the electrical signal, and the vibration of the electrical signal causes an AC perturbation signal to be generated on the battery side of the unmanned aerial vehicle;

[0008] Collect the current and voltage data of the UAV battery during vibration flight, and calculate the AC impedance of the UAV battery based on the collected current and voltage data.

[0009] Further, the method also includes the following steps:

[0010] Control the UAV to perform different forms of vibration flight. Different forms of vibration flight can generate vibrations of different electrical signals on the load side of the UAV's power system, and the vibrations of the electrical signals cause different frequency AC perturbation signals to be generated on the battery side of the UAV;

[0011] Collect the current and voltage signals of the battery during each vibration flight respectively, and calculate the AC impedance of the UAV battery based on the collected current and voltage data;

[0012] Obtain the electrochemical impedance spectrum of the battery based on the impedance values at each frequency, and judge the state of the UAV battery.

[0013] Further, before controlling the UAV to perform vibration flight, the following steps are first executed:

[0014] Detect the UAV to determine that the UAV is safe and stable and can perform the vibration flight required for testing.

[0015] Further, the detection of the UAV includes software detection, hardware detection, and flight environment detection of the UAV.

[0016] Further, the vibration flight includes performing short-distance up and down vibration flight, or short-distance left and right vibration flight, or yaw angle vibration flight, or inclined vibration flight with an angle to the horizontal plane.

[0017] Further, before controlling the UAV to perform vibration flight, the following steps are also executed:

[0018] Conduct a vibration flight test on the UAV, adjust the vibration rules during vibration flight until the required AC perturbation signal is detected on the battery side of the UAV's power system. The vibration rules include flight distance and speed changes. Record the vibration rules corresponding to the UAV when the required AC perturbation signal is obtained. The UAV is configured to perform vibration flight using the recorded vibration rules.

[0019] Further, the AC perturbation signal is a sinusoidal AC perturbation signal.

[0020] Further, before controlling the UAV to perform vibration flight, the following steps are also executed:

[0021] Conduct dynamic modeling of the UAV to obtain the vibration rules of the aircraft including flight distance and speed changes under AC perturbation. The UAV is configured to perform vibration flight using the calculated vibration rules.

[0022] The AC impedance detection method for unmanned aerial vehicles (UAVs) of the present invention does not require additional hardware devices or significant modification to the power train system of the UAV. By simply adjusting the flight mode of the UAV to perform vibrating flight and generating corresponding disturbance signals, AC impedance detection can be achieved, greatly reducing the cost of implementing AC impedance detection for UAV batteries. Moreover, the method of the present invention is easy to operate and implement, enabling on-line AC impedance detection of UAV batteries, improving the real-time performance and convenience of detection, and reducing the difficulty threshold for the application of AC impedance detection technology. Using the method of the present invention to achieve detection based on the change of the UAV's own flight mode does not damage the original modular structure of the UAV and the integrity of the power train system, which is beneficial to maintaining the stability and reliability of the UAV. Description of the Drawings

[0023] Figure 1 It is a schematic diagram of the internal resistance model of the UAV battery;

[0024] Figure 2 It is a schematic diagram of the impedance spectrum of the UAV battery;

[0025] Figure 3 It is a schematic diagram of the steps of the AC impedance detection method for UAVs in an embodiment;

[0026] Figure 4 It is a schematic diagram of vibrating flight up and down;

[0027] Figure 5 It is a schematic diagram of vibrating flight left and right;

[0028] Figure 6 It is a schematic diagram of vibrating flight with yaw angle;

[0029] Figure 7 It is inclined vibrating flight with an angle to the horizontal plane;

[0030] Figure 8 It is a schematic diagram of the steps of the AC impedance detection method for UAVs in another embodiment;

[0031] Figure 9 It is the internal structure diagram of a computer device in an embodiment. Detailed Embodiments

[0032] See Figure 3 , a method for detecting AC impedance of a UAV according to the present invention includes the following steps:

[0033] Step 1: Control the drone to perform vibrating flight. Vibrating flight can cause power changes on the load side of the drone's power system, thereby generating electrical signal vibrations. The electrical signal vibrations cause an AC disturbance signal to be generated on the battery side of the drone.

[0034] Step 2: During the vibrating flight, collect the current and voltage data of the drone's battery, and calculate the AC impedance of the drone's battery based on the collected current and voltage data.

[0035] On the battery side of the drone, the voltage and current can be measured using the existing sensors of the drone. The AC disturbance signal is included in the voltage and current and can be filtered and extracted. In Step 2, by collecting the current and voltage data of the drone's battery to calculate the AC impedance, dividing the AC voltage signal by the AC current signal can calculate the AC internal resistance value of the battery, realizing the measurement of the battery's AC impedance, which can be fully achieved based on the existing configuration of the drone without hardware modification.

[0036] The existing technology mainly relies on specific impedance detection equipment or modifies power electronic equipment to generate AC disturbances, relying heavily on additional hardware, which limits its application in online detection scenarios. The solution provided in the embodiment abandons the traditional idea of hardware dependence and creatively uses the mechanical vibration characteristics of the drone to naturally generate the required electrical signal disturbances on the load side, providing a unique solution for the AC impedance detection of the drone's battery. The detection method based on vibrating flight provided in the embodiment is a brand-new technical idea. Whether it is a drone using traditional lithium batteries or fuel cells, the AC impedance detection method in the embodiment can be used for detection, no longer restricted by hardware equipment, and can be easily applied to various types of drones.

[0037] Some existing online AC impedance detection technologies use power electronic equipment to generate AC disturbances, but they need to make significant modifications to the powertrain system, resulting in high transformation costs. Moreover, this kind of transformation only increases the cost for the drone. Drones are sensitive to weight and volume, and the traditional hardware solution cannot meet its online detection requirements. In addition, the transformation of power electronic equipment will destroy the modular design, increase the system complexity, and may also affect the stability of the drone. Compared with the existing technology, this solution only changes the flight mode to perform vibrating flight, completely does not involve hardware modification of the power system, breaks through the dilemma of the existing technology in the transformation of the drone's power system, and realizes AC impedance detection in an extremely ingenious and low-cost way.

[0038] The drone itself has the ability to flexibly adjust the flight mode. The solution provided in the embodiment combines the flight adjustment ability of the drone with AC impedance detection. By controlling the drone to perform vibrating flight, such as Figures 4 to 7As shown, it can be short-distance up-and-down vibration flight, short-distance left-and-right vibration flight, yaw angle vibration flight, or inclined vibration flight with an angle inclination to the horizontal plane. In addition, it can also be other vibration flight modes, as long as it can generate an electrical signal vibration on the load side of the power system of the drone, and the electrical signal vibration is conducted to the power supply port to provide the required AC perturbation signal for AC impedance detection. The solution of the present invention is designed based on the characteristics of the drone itself and closely fits the application scenario of the drone, making innovative use of drone resources.

[0039] The present invention can generate the AC perturbation signal required for AC impedance detection only by performing a relatively simple operation of adjusting the flight mode for vibration flight. Compared with the traditional method, it can simplify the detection process, without the need for complex hardware installation and debugging processes, nor the need to modify the power system of the drone, which can reduce the implementation difficulty, reduce the equipment cost, reduce the risk of hardware damage and the high transformation cost that may be brought by the transformation, making the AC impedance detection of the battery on the drone more convenient and low-cost, and having important significance for improving the monitoring level of the drone battery state.

[0040] In an embodiment of the present invention, before controlling the drone to perform vibration flight, the following steps are first executed:

[0041] Detect the drone to determine that the drone is safe and stable and can perform the vibration flight required for the test.

[0042] In implementation, detecting the drone includes software detection, hardware detection, and flight environment detection of the drone.

[0043] Among them, for the hardware detection of the drone, it includes the detection of the drone body structure, power system, flight control system and other structures, checking whether there are cracks and deformations in each component of the fuselage, whether the connections of each component are firm, detecting whether the motor and battery can work normally, and detecting and checking the flight control sensors, such as gyroscopes, accelerometers, and compasses, whether they can work normally;

[0044] For the software detection of the drone, it includes confirming whether the flight control algorithm is correctly set, confirming whether the vibration rule of the vibration flight is correctly set, and checking whether the safety protection mechanism in the software is perfect.

[0045] For the flight environment detection of the drone, it includes observing the wind speed, wind direction and weather, and confirming that there are no tall obstacles in the flight area.

[0046] During the vibration flight test for AC impedance detection, the safe and stable operation of the drone is the basis for obtaining accurate test data. Through comprehensive detection of the drone's software, hardware, and flight environment, various potential hazards that may affect flight safety can be discovered in advance, ensuring that the vibration flight test can be carried out smoothly, reducing test interruptions and repeated tests caused by equipment failures or environmental problems. Through pre-detection, the success rate and efficiency of the test can be improved, the process of AC impedance detection can be accelerated, and work efficiency can be enhanced.

[0047] In an embodiment of the present invention, in order to obtain the desired vibration flight rules, before controlling the drone to perform vibration flight, the following steps can also be executed:

[0048] Conduct a vibration flight test on the drone, adjust the vibration rules during vibration flight until the required AC perturbation signal is detected on the battery side of the drone's power system, usually a sinusoidal AC perturbation signal. The vibration rules include flight distance and speed changes. Record the corresponding vibration rules of the drone when the required sinusoidal AC perturbation signal is obtained. The drone is configured to perform vibration flight using the recorded vibration rules.

[0049] In the embodiment, by actually controlling the drone to perform various forms of vibration flight and real-time monitoring and recording the AC perturbation signal conditions on the battery side during flight, data can be intuitively obtained, and the corresponding relationship between different vibration modes and the generated AC perturbation signals can be clarified. In multiple vibration flight experiments with different amplitudes and frequencies, accurately measure and analyze the current and voltage fluctuations at the battery port during each flight. Based on the actual data, it can be clearly verified whether vibration flight can effectively generate AC perturbation signals that meet the requirements of AC impedance detection.

[0050] The vibration flight test is carried out for a specific drone, fully considering the unique software and hardware characteristics of each drone. Whether it is a small consumer drone or a large professional drone, suitable vibration rules for itself can be found through experimental tests to achieve AC perturbation signals.

[0051] In an embodiment of the present invention, in order to obtain the desired vibration flight rules, before controlling the drone to perform vibration flight, the following steps can also be executed:

[0052] Perform dynamic modeling of the aircraft for the drone and establish the basic equation of the aircraft power system under the condition of no perturbation;

[0053] Analyze the changes in the force and torque output by the motor caused by introducing the AC perturbation electrical signal on the fuel cell side, and introduce the preset AC perturbation as a small signal into the basic equation to form a small signal model of the power system;

[0054] Using numerical calculation methods, such as the Runge-Kutta method, to solve the small-signal model with AC perturbation. Given the initial conditions, the time is divided into discrete small time steps, and the changes in the state variables of the aircraft's position and speed at each time step are calculated through iterative calculations, obtaining the vibration rules of the aircraft under AC perturbation that include flight distance and speed changes. The calculated vibration rules are used to control the drone to perform vibration flight.

[0055] In the embodiment, based on the dynamic principle of the drone, the motor characteristics, and the battery characteristics, dynamic modeling of the aircraft is carried out to simulate the vibration flight process of the drone. Through the calculation and analysis of the model, it can be theoretically analyzed under what vibration flight modes the expected AC perturbation signal can be generated, and then verified through actual vibration analysis. Conducting dynamic modeling of the aircraft enables obtaining various possible vibration flight modes during the actual implementation process, providing convenience for determining feasible vibration rules. Numerical simulation tools, such as MATLAB / Simulink, can be used to model and simulate the entire system to verify whether the perturbation signals generated on the load side under different flight modes meet the expectations.

[0056] See Figure 8 , in the embodiment of the present invention, another AC impedance detection method for drones is provided, including the following steps:

[0057] Step 1: Detect the drone to determine that the drone is safe and stable and can perform the vibration flight required for testing;

[0058] Step 2: Control the drone to perform different forms of vibration flight. Different forms of vibration flight can generate vibrations of different electrical signals on the load side of the drone's power system, and the vibrations of the electrical signals cause different frequency AC perturbation signals to be generated on the battery side of the drone;

[0059] Step 3: Collect the current and voltage signals of the battery during each vibration flight respectively, and calculate the AC impedance of the drone battery based on the collected current and voltage data;

[0060] Step 4: Obtain the electrochemical impedance spectrum of the battery based on the impedance values at each frequency and judge the state of the drone battery.

[0061] In implementation, potential faults inside the battery can be detected before flight through the obtained electrochemical impedance spectroscopy, and can be promptly eliminated to avoid safety accidents such as plane crashes caused by battery failures during flight; the battery model established based on the obtained impedance spectrum data can accurately calculate the remaining flight time of the battery in the current state, enabling the drone operator to make preparations in advance, ensuring the safe return of the drone, preventing sudden power-off of the drone during flight due to inaccurate power estimation, and furthermore, a charge and discharge plan can be formulated according to the battery aging degree and health status reflected by the electrochemical impedance spectroscopy to help extend the battery cycle service life.

[0062] In an embodiment of the present invention, a computer device is further provided, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the method for alternating current impedance detection for a drone as described above is implemented.

[0063] This computer device may be a terminal, and its internal structure diagram may be as Figure 9 shown. This computer device includes a processor, a memory, a network interface, a display screen, and an input device connected through a bus. Among them, the processor of this computer device is used to provide computing and control capabilities. The memory of this computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of this computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, the method for alternating current impedance detection for a drone is implemented. The display screen of this computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of this computer device may be a touch layer covering the display screen, or may be a button, a trackball, or a touchpad provided on the housing of the computer device, or may also be an external keyboard, a touchpad, or a mouse, etc.

[0064] The memory may be, but is not limited to, a random access memory (Random Access Memory, abbreviated as: RAM), a read-only memory (Read Only Memory, abbreviated as: ROM), a programmable read-only memory (Programmable Read-Only Memory, abbreviated as: PROM), an erasable programmable read-only memory (Erasable Programmable Read-Only Memory, abbreviated as: EPROM), an electrically erasable programmable read-only memory (Electric Erasable Programmable Read-Only Memory, abbreviated as: EEPROM), etc. Among them, the memory is used to store a program, and after receiving an execution instruction, the processor executes the program.

[0065] The processor can be an integrated circuit chip with the ability to process signals. The above-mentioned processor can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc. The processor can also be other general-purpose processors, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. It can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc.

[0066] Those skilled in the art can understand that Figure 9 the structure shown in [the figure] is only a block diagram of some structures related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0067] In an embodiment of the present invention, there is also provided a computer-readable storage medium, on which a program is stored, and when the program is executed by a processor, it implements the AC impedance detection method for an unmanned aerial vehicle as described above.

[0068] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a computer device, or a computer program product. Therefore, the embodiments of the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the embodiments of the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0069] Embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of methods, computer devices, or computer program products according to embodiments of the present invention. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing terminal devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing terminal devices generate a device for implementing the functions specified in the flowchart and / or block diagram.

[0070] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing terminal devices to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device that implements the functions specified in the flowchart.

[0071] In an embodiment of the present invention, a computer program product is further provided, including a computer program / instructions, and when the computer program / instructions are executed by a processor, the steps of the above method are implemented.

[0072] In actual application processes, the above computer program product includes, but is not limited to, drones, smartphones, desktop computers, laptop computers, tablet computers, host computers, server platforms, etc., and no specific limitations are made here.

[0073] The above has introduced in detail the application of the AC impedance detection method, computer device, computer-readable storage medium, and computer program product provided by the present invention for drones. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation on the present invention.

Claims

1. An AC impedance detection method for an unmanned aerial vehicle, characterized in that It includes the following steps: Control the drone to perform vibration flights in different forms. The vibration flights in different forms can generate vibrations of different electrical signals on the load side of the power system of the drone, and the vibrations of the electrical signals cause alternating current disturbance signals of different frequencies to be generated on the battery side of the drone; Collect the current and voltage signals of the battery during each vibration flight respectively, and calculate the AC impedance of the drone battery based on the collected current and voltage data; Obtain the electrochemical impedance spectrum of the battery based on the impedance values at various frequencies, and judge the state of the drone battery.

2. The AC impedance detection method for an unmanned aerial vehicle according to claim 1, characterized in that, Before controlling the drone to perform vibration flight, first perform the following steps: Detect the drone to determine that the drone is safe and stable and can perform the vibration flight required for the test.

3. The AC impedance detection method for an unmanned aerial vehicle according to claim 1, wherein: The vibration flight includes performing short-distance up and down vibration flight or short-distance left and right vibration flight or yaw angle vibration flight or inclined vibration flight with an angle to the horizontal plane.

4. A method for detecting the AC impedance of a drone according to claim 1, characterized in that: Before controlling the drone to perform vibration flight, the following steps are also performed: Conduct a vibration flight test on the drone, adjust the vibration rules during vibration flight until the required alternating current disturbance signal is detected on the battery side of the power system of the drone. The vibration rules include flight distance and speed change. Record the vibration rules corresponding to the drone when the required alternating current disturbance signal is obtained, and the drone is configured to perform vibration flight using the recorded vibration rules.

5. The alternating current impedance detection method for an unmanned aerial vehicle according to claim 1, wherein: The alternating current disturbance signal is a sinusoidal alternating current disturbance signal.

6. The AC impedance detection method for an unmanned aerial vehicle according to claim 1, wherein: Before controlling the drone to perform vibration flight, the following steps are also performed: Perform dynamic modeling of the aircraft on the drone to obtain the vibration rules including flight distance and speed change under alternating current disturbance. The drone is configured to perform vibration flight using the calculated vibration rules.

7. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that: When the processor executes the computer program, it implements the method for detecting AC impedance of a drone as described in any one of claims 1 to 6.

8. A computer-readable storage medium having a program stored thereon, characterized in that: When the program is executed by the processor, it implements the method for detecting AC impedance of a drone as described in any one of claims 1 to 6.

9. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, it implements the steps of the method as described in any one of claims 1 to 6.

Images