Alternating current impedance detection method and device for unmanned aerial vehicle

Abstract

The invention provides an alternating-current impedance detection method and device for an unmanned aerial vehicle, which do not depend on additional hardware, can reduce the cost of alternating-current impedance detection of a battery of the unmanned aerial vehicle, is easy to operate and implement, and comprises the following steps: controlling the unmanned aerial vehicle to vibrate and fly; the vibration flight can enable the load side of a power system of the unmanned aerial vehicle to generate power change so as to generate vibration of an electric signal, and the vibration of the electric signal enables the battery side of the unmanned aerial vehicle to generate an alternating current disturbance signal; collecting current and voltage data of the battery of the unmanned aerial vehicle during vibration flight, and calculating the alternating current impedance of the battery of the unmanned aerial vehicle according to 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 in particular to an alternating current impedance detection method and device for unmanned aerial vehicles. Background Art

[0002] As an electrochemical power source, the output characteristic of a battery or fuel cell is in the form of open circuit voltage plus internal impedance, such as Figure 1 As shown. Among them, the internal impedance is a complex nonlinear impedance, and the impedance spectrum of the battery is as follows Figure 2 As shown, the horizontal axis is the real part and the vertical axis is 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 AC impedance detection technology is to superimpose a small AC disturbance signal on the normal DC output current at the output end of the battery or fuel cell, and the frequency depends on the need to obtain the spectrum range. Then, the feedback voltage of the battery or fuel cell is detected, and the AC part is extracted. The AC impedance of the battery or fuel cell can be calculated from the injected AC current and the feedback AC voltage signal, and then the current power supply state is judged based on the impedance information obtained.

[0003] Traditionally, AC impedance technology is generally used in laboratories. It generates AC disturbances through specific impedance detection equipment. Additional hardware equipment is required. In addition, the electrochemical workstation for testing battery AC impedance is expensive and cannot be used for online detection.

[0004] In some applications and academic research, power electronic devices connected to batteries and fuel cells, such as dc / dc converters, are also used to generate AC disturbances to achieve online AC impedance detection technology. This technology requires changes to the powertrain system and cannot use traditional modular power electronic devices, which has a large modification cost in practical applications. Summary of the invention

[0005] In view of the above problems, the present invention provides an AC impedance detection method and device for a drone, which does not rely on additional hardware, can reduce the cost of realizing AC impedance detection of drone batteries, and is easy to operate and implement.

[0006] The technical solution is as follows: an AC impedance detection method for a drone comprises the following steps: Controlling the drone to perform vibration flight, wherein the vibration flight can cause power changes on the load side of the power system of the drone to generate vibrations of electrical signals, and the vibrations of the electrical signals cause the battery side of the drone to generate an AC disturbance signal; The current and voltage data of the drone battery are collected during the vibration flight, and the AC impedance of the drone battery is calculated based on the collected current and voltage data.

[0007] Further, the method further comprises the following steps: Control the drone to perform different forms of vibration flight. Different forms of vibration flight can generate different electrical signal vibrations on the load side of the drone's power system. The vibration of the electrical signal causes the drone's battery side to generate AC disturbance signals of different frequencies. The current and voltage signals of the battery during each vibration flight are collected respectively, and the AC impedance of the drone battery is calculated based on the collected current and voltage data; According to the impedance values ​​at various frequencies, the electrochemical impedance spectrum of the battery is obtained to determine the status of the drone battery.

[0008] Furthermore, before controlling the drone to perform vibration flight, perform the following steps: Test the drone to make sure it is safe and stable and capable of the vibration flight required for the test.

[0009] Furthermore, the detection of the drone includes software detection, hardware detection and flight environment detection of the drone.

[0010] Furthermore, the vibration flight includes 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 inclined to the horizontal plane.

[0011] Furthermore, before controlling the drone to perform vibration flight, the following steps are performed: A vibration flight test is performed on the UAV, and the vibration rules during the vibration flight are adjusted until the required AC disturbance signal is detected on the battery side of the power system of the UAV, the vibration rules including flight distance and speed changes, and the vibration rules corresponding to the UAV when the required AC disturbance signal is obtained are recorded. The UAV is configured to perform vibration flight using the recorded vibration rules.

[0012] Furthermore, the AC disturbance signal is a sinusoidal AC disturbance signal.

[0013] Furthermore, before controlling the drone to perform vibration flight, the following steps are performed: The UAV is dynamically modeled to obtain the vibration rules of the aircraft including the flight distance and speed changes under AC disturbance. The UAV is configured to perform vibration flight using the calculated vibration rules.

[0014] The AC impedance detection method for a drone of the present invention does not require additional hardware equipment or major modifications to the powertrain system of the drone. AC impedance detection can be achieved by simply adjusting the flight mode of the drone to perform vibration flight and generate a corresponding disturbance signal, thereby greatly reducing the cost of realizing AC impedance detection of drone batteries. In addition, the method of the present invention is easy to operate and implement, and can realize online AC impedance detection of drone batteries, thereby improving the real-time and convenience of detection, and reducing the difficulty threshold of applying AC impedance detection technology. The method of the present invention is used to realize detection based on changes in the drone's own flight mode, which will not destroy the original modular structure of the drone and the integrity of the powertrain system, and is conducive to maintaining the stability and reliability of the drone. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the battery internal resistance model of the drone; Figure 2 This is a schematic diagram of the battery impedance spectrum of the drone; Figure 3 Schematic diagram of the steps of an AC impedance detection method for a drone in one embodiment; Figure 4 A schematic diagram of the upward and downward vibration flight; Figure 5 It is a schematic diagram of left and right vibration flight; Figure 6 Schematic diagram of yaw angle vibration flight; Figure 7 It is an inclined vibration flight with an angle inclined to the horizontal plane; Figure 8 is a schematic diagram of the steps of an AC impedance detection method for a drone in another embodiment; Fig. 9 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0016] See Figure 3 , an AC impedance detection method for a drone of the present invention comprises the following steps: Step 1: Control the drone to perform vibration flight. Vibration flight can cause power changes on the load side of the drone's power system, thereby generating electrical signal vibrations. The vibrations of the electrical signals cause the battery side of the drone to generate an AC disturbance signal. Step 2: Collect the current and voltage data of the drone battery during the vibration flight, and calculate the AC impedance of the drone battery based on the collected current and voltage data.

[0017] On the battery side of the drone, the voltage and current can be measured using the drone's existing sensors, and the AC disturbance signal is contained in the voltage and current and can be filtered and extracted. Step 2 collects the current and voltage data of the drone battery to calculate the AC impedance. By dividing the AC voltage signal by the AC current signal, the AC internal resistance of the battery can be calculated, and the battery AC impedance can be measured. This can be completely implemented based on the drone's existing configuration without the need for hardware changes.

[0018] The existing technology mainly relies on specific impedance detection equipment or the modification of power electronic equipment to generate AC disturbances, and is heavily dependent on additional hardware, which limits its application in online detection scenarios. The solution provided in the embodiment abandons the traditional hardware-dependent idea and creatively utilizes the mechanical vibration characteristics of the drone to naturally generate the required electrical signal disturbance on the load side, providing a unique solution for the AC impedance detection of drone batteries; the detection method based on vibration flight provided in the embodiment is a brand-new technical idea. Whether it is a drone using a traditional lithium battery or a fuel cell, the AC impedance detection method in the embodiment can be used for detection. It is no longer limited by the constraints of hardware equipment and can be easily applied to various types of drones.

[0019] Although some existing AC impedance online detection technologies use power electronic devices to generate AC disturbances, they require major changes to the powertrain system, resulting in high modification costs. Moreover, such modifications only increase costs for drones. Drones are sensitive to weight and volume, and traditional hardware solutions cannot meet their online detection needs. Moreover, the modification of power electronic devices will destroy the modular design, increase system complexity, and may also affect the stability of drones. Compared with the existing technology, this solution only changes the flight mode to perform vibration flight, and does not involve hardware modification of the power system at all. It breaks through the difficulties of existing technologies in the modification of drone power systems, and realizes AC impedance detection in an extremely clever and low-cost way.

[0020] The drone itself has the ability to flexibly adjust the flight mode. The solution provided in the embodiment combines the flight adjustment capability of the drone with AC impedance detection, and controls the drone to perform vibration flight, such as Figures 4 to 7 As shown, it can be a short-distance upward and downward vibration flight, a short-distance left and right vibration flight, a yaw angle vibration flight, or an inclined vibration flight with an angle inclined to the horizontal plane. In addition, it can also be other vibration flight modes. It only needs to generate vibrations of electrical signals on the load side of the power system of the UAV, and the vibrations of the electrical signals are transmitted to the power port to provide the required AC disturbance signal for AC impedance detection. The solution of the present invention is based on the design of the characteristics of the UAV itself, and closely fits the application scenarios of the UAV, making innovative use of UAV resources.

[0021] The present invention can generate the AC disturbance signal required for AC impedance detection only by adjusting the flight mode to perform vibration flight, which is a relatively simple operation. Compared with the traditional method, the detection process can be simplified, and there is no need for complicated hardware installation and debugging process, nor is there any need to modify the power system of the UAV. It can reduce the difficulty of implementation, reduce equipment costs, reduce the risk of hardware damage caused by modification and the high modification cost, and make AC impedance detection of batteries on drones more convenient and low-cost, which is of great significance for improving the level of drone battery status monitoring.

[0022] In one embodiment of the present invention, before controlling the drone to perform vibration flight, the following steps are performed: Test the drone to make sure it is safe and stable and capable of the vibration flight required for the test.

[0023] During implementation, the drone is tested, including software testing, hardware testing, and flight environment testing.

[0024] Among them, the hardware inspection of drones includes the inspection of the drone's fuselage structure, power system, flight control system and other structures, checking whether the various parts of the fuselage have cracks or deformation, whether the connections between the parts are firm, whether the motor and battery can work normally, and whether the flight control sensors such as gyroscopes, accelerometers, and compasses can work normally; Software testing of drones includes confirming whether the flight control algorithm is set correctly, confirming whether the vibration rules of vibration flight are set correctly, and checking whether the safety protection mechanism in the software is complete.

[0025] The flight environment detection of the drone includes observing the wind speed, wind direction and weather, and confirming that there are no tall obstacles in the flight area.

[0026] When conducting vibration flight tests for AC impedance detection, the safe and stable operation of the UAV is the basis for obtaining accurate test data. Through comprehensive testing of the UAV software, hardware and flight environment, various hidden dangers that may affect flight safety can be discovered in advance, ensuring that it can smoothly conduct vibration flight tests and reduce test interruptions and repeated tests caused by equipment failure or environmental problems. Through pre-testing, 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 improved.

[0027] In one embodiment of the present invention, in order to obtain the desired vibration flight rules, before controlling the UAV to perform vibration flight, the following steps may be performed: Perform a vibration flight test on the UAV, adjust the vibration rules during the vibration flight, until the required AC disturbance signal, usually a sinusoidal AC disturbance 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 sinusoidal AC disturbance signal is obtained. The UAV is configured to use the recorded vibration rules for vibration flight.

[0028] In the embodiment, by actually controlling the drone to perform various forms of vibration flight, the AC disturbance signal on the battery side is monitored and recorded in real time during the flight, so that data can be obtained intuitively and the correspondence between different vibration modes and the generated AC disturbance signals can be clearly determined. In multiple vibration flight experiments with different amplitudes and frequencies, the current and voltage fluctuations at the battery port during each flight are accurately measured and analyzed. Based on the actual data, it can be clearly verified whether the vibration flight can effectively generate an AC disturbance signal that meets the requirements of AC impedance detection.

[0029] Vibration flight tests are conducted on specific drones, taking into full account the unique software and hardware characteristics of each drone. Whether it is a small consumer drone or a large professional drone, each drone can find a vibration rule suitable for itself through experimental testing to realize the AC disturbance signal.

[0030] In one embodiment of the present invention, in order to obtain the desired vibration flight rules, before controlling the UAV to perform vibration flight, the following steps may be performed: Carry out dynamic modeling of UAV and establish the basic equations of the aircraft power system under undisturbed conditions; Analyze the changes in the force and torque output by the motor caused by the AC disturbance electrical signal introduced into the fuel cell side, introduce the preset AC disturbance as a small signal into the basic equation, and form a small signal model of the power system; Use numerical calculation methods, such as the Runge-Kutta method, to solve the small signal model with AC disturbance. Given the initial conditions, divide the time into discrete small steps, and iteratively calculate the changes in the state variables of the position and velocity of the aircraft at each time step to obtain the vibration rules of the aircraft under AC disturbance, including the changes in flight distance and speed. Use the calculated vibration rules to control the UAV to perform vibrating flight.

[0031] In the embodiment, the aircraft dynamic modeling of the UAV is performed based on the dynamic principle, motor characteristics, and battery characteristics of the UAV to simulate the vibration flight process of the UAV. Through the calculation and analysis of the model, it can be theoretically analyzed: under what vibration flight mode the expected AC disturbance signal can be generated, and then verified through actual vibration analysis. The aircraft dynamic modeling of the UAV makes it possible to obtain a variety of possible vibration flight modes during the actual implementation process, which facilitates the determination of feasible vibration rules. Numerical simulation tools such as MATLAB / Simulink can be used to model and simulate the entire system to verify whether the disturbance signal generated on the load side under different flight modes meets expectations.

[0032] See Figure 8 In an embodiment of the present invention, another AC impedance detection method for a drone is provided, comprising the following steps: Step 1: Test the drone to make sure it is safe and stable and can perform the vibration flight required for the test; Step 2: Control the drone to perform different forms of vibration flight. Different forms of vibration flight can generate different electrical signal vibrations on the load side of the drone's power system. The vibration of the electrical signal causes the drone's battery side to generate AC disturbance signals of different frequencies. Step 3: Collect the current and voltage signals of the battery during each vibration flight, and calculate the AC impedance of the drone battery based on the collected current and voltage data; Step 4: Based on the impedance values ​​at each frequency, obtain the electrochemical impedance spectrum of the battery and determine the status of the drone battery.

[0033] During implementation, the obtained electrochemical impedance spectrum can detect potential fault hazards inside the battery before flight, which can be eliminated in time to avoid safety accidents such as crashes caused by battery failure during flight; the battery model established based on the obtained impedance spectrum data can accurately calculate the remaining battery life of the battery in the current state, allowing pilots to prepare in advance to ensure the safe return of the drone and prevent sudden power outages in flight due to inaccurate power estimation. In addition, a charging and discharging plan can be formulated based on the battery aging degree and health status reflected by the electrochemical impedance spectrum to help extend the battery cycle life.

[0034] In an embodiment of the present invention, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the AC impedance detection method for a drone as described above is implemented.

[0035] The computer device may be a terminal, and its internal structure diagram may be as follows: Fig. 9As shown. The computer device includes a processor, a memory, a network interface, a display screen and an input device connected via a bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the 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 the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, an AC impedance detection method for a drone is implemented. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0036] The memory may be, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable read-only memory (EEPROM), etc. The memory is used to store programs, and the processor executes the programs after receiving the execution instruction.

[0037] The processor can be an integrated circuit chip with signal processing capabilities. The above-mentioned processor can be a general-purpose processor, including a central processing unit (Central Processing Unit, referred to as: CPU), a network processor (Network Processor, referred to as: NP), etc. The processor can also be other general-purpose processors, digital signal processors (Digital Signal Processor, DSP), application-specific integrated circuits (Application Specific Integrated Circuit, ASIC), field programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates 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. The various methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc.

[0038] Those skilled in the art will understand that Fig. 9 The structure shown in the figure is only a block diagram of a part of the structure 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 certain components, or have a different arrangement of components.

[0039] In an embodiment of the present invention, a computer-readable storage medium is further provided, on which a program is stored. When the program is executed by a processor, the AC impedance detection method for a drone as described above is implemented.

[0040] Those skilled in the art will appreciate that the embodiments of the embodiments of the present invention may be provided as methods, computer devices, or computer program products. Therefore, the embodiments of the present invention may take the form of complete hardware embodiments, complete software embodiments, or embodiments combining software and hardware. Moreover, the embodiments of the present invention may take the form of computer program products 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 codes.

[0041] The embodiments of the present invention are described with reference to flowcharts and / or block diagrams of methods, computer devices, or computer program products according to the 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 device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate a device for implementing the functions specified in the flowcharts and / or.

[0042] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device that implements the functions specified in the flowchart.

[0043] In an embodiment of the present invention, a computer program product is also provided, comprising a computer program / instruction, which implements the steps of the above method when executed by a processor.

[0044] In actual application, the above-mentioned computer program products include but are not limited to: drones, smart phones, desktop computers, laptops, tablet computers, host computers and server platforms, etc., and no specific restrictions are made here.

[0045] The above is a detailed introduction to the application of the AC impedance detection method for drones, computer devices, computer-readable storage media, and computer program products provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An AC impedance detection method for a drone, characterized in that: The following steps are involved: Controlling the UAV to perform vibration flight, wherein the vibration flight can cause power changes on the load side of the UAV's power system to generate vibrations of electrical signals, and the vibrations of the electrical signals cause the battery side of the UAV to generate an AC disturbance signal; The current and voltage data of the drone battery are collected during the vibration flight, and the AC impedance of the drone battery is calculated based on the collected current and voltage data.

2. The AC impedance detection method for a drone according to claim 1, characterized in that: Before controlling the drone for vibrating flight, perform the following steps: Test the drone to make sure it is safe and stable and capable of the vibration flight required for the test.

3. The AC impedance detection method for a drone according to claim 1, characterized in that: The vibration flight includes 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 inclined to the horizontal plane.

4. The AC impedance detection method for a drone according to claim 1, characterized in that: Before controlling the drone to perform vibration flight, perform the following steps: A vibration flight test is performed on the UAV, and the vibration rules during the vibration flight are adjusted until the required AC disturbance signal is detected on the battery side of the power system of the UAV, the vibration rules including flight distance and speed changes, and the vibration rules corresponding to the UAV when the required AC disturbance signal is obtained are recorded. The UAV is configured to perform vibration flight using the recorded vibration rules.

5. The AC impedance detection method for a drone according to claim 1, characterized in that: The AC disturbance signal is a sinusoidal AC disturbance signal.

6. The AC impedance detection method for a drone according to claim 1, characterized in that: Before controlling the drone to perform vibration flight, perform the following steps: The UAV is dynamically modeled to obtain the vibration rules of the aircraft including the flight distance and speed changes under AC disturbance. The UAV is configured to perform vibration flight using the calculated vibration rules.

7. The AC impedance detection method for a drone according to claim 1, characterized in that: The following steps are also included: Control the drone to perform different forms of vibration flight. Different forms of vibration flight can generate different electrical signal vibrations on the load side of the drone's power system. The vibration of the electrical signal causes the drone's battery side to generate AC disturbance signals of different frequencies. The current and voltage signals of the battery during each vibration flight are collected respectively, and the AC impedance of the drone battery is calculated based on the collected current and voltage data; According to the impedance values ​​at various frequencies, the electrochemical impedance spectrum of the battery is obtained to determine the status of the drone battery.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the AC impedance detection method for a drone as described in any one of claims 1 to 7 is implemented.

9. A computer-readable storage medium having a program stored thereon, characterized in that: When the program is executed by the processor, the AC impedance detection method for a drone as described in any one of claims 1 to 7 is implemented.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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