A secondary filtering implementation method and system for a brushless electronic governor of a drone

Abstract

The application provides a kind of unmanned aerial vehicle brushless electric governor secondary filtering implementation method and system, the steps of the method include: using three-phase circuit to collect the initial signal output by brushless motor, and the initial signal is frequency divided, the operation parameters of brushless motor in the first historical working period and the second historical working period are recorded in the initial signal;Through electronic speed regulator access high-frequency signal after frequency division, the high-frequency signal is filtered twice in the electronic speed regulator to obtain a filtered signal, the frequency domain signal is obtained by Fourier transform on the filtered signal, the first historical period modulation frequency and the second historical period modulation frequency are calculated respectively based on the frequency domain signal, the optimized modulation frequency is calculated based on the first historical period modulation frequency and the second historical period modulation frequency, and the control signal corresponding to the optimized modulation frequency is output to the brushless motor.This scheme generates stable control signal in electronic speed regulator, reduces the operation noise of brushless motor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of unmanned aerial vehicles, and in particular to a secondary filtering implementation method and system for a brushless electronic speed controller of an unmanned aerial vehicle. BACKGROUND

[0002] The current trend of quadcopter unmanned aerial vehicle technology is towards miniaturization and intelligence. For the core motor part of the unmanned aerial vehicle system, the mainstream component is a brushless motor. Compared with a brushed motor, a brushless motor consumes less power, has low vibration noise, and has a long service life using a bearing outer rotor. It has great advantages and is the mainstream solution currently used.

[0003] An electronic speed controller (ESC) is used in the control system of an unmanned aerial vehicle to control the speed of a brushless motor, thereby realizing controllable flight. A simple cost solution for a brushless electronic speed controller is a combination of a single-chip microcomputer and a high-current MOS tube: the single-chip microcomputer is responsible for controlling analog or digital signals, and the MOS tube controls the high-speed on-off of the current, thereby realizing a three-phase circuit to control the rotational speed and direction of the motor.

[0004] The current brushless electronic speed controller protocol is mainly PWM and Dshot protocol. PWM is an analog signal, which is a very mature electronic speed controller control signal. Its characteristic is a certain high-frequency square wave, and the effective value is determined by the duration of the high level, thereby realizing the analog control of the size. Dshot is a digital signal, which realizes the transmission of a group of signals by determining the potential of a high-frequency square wave, which contains the digital coding and verification of the analog quantity, and can realize the transmission of the control size.

[0005] However, the existing electronic speed controller firmware cannot effectively reduce the noise of the incoming motor signal, resulting in a high noise level of the motor. SUMMARY

[0006] In view of this, embodiments of the present application provide a secondary filtering implementation method for a brushless electronic speed controller of an unmanned aerial vehicle to eliminate or improve one or more defects in the prior art.

[0007] One aspect of the present application provides a secondary filtering implementation method for a brushless electronic speed controller of an unmanned aerial vehicle, the steps of the method comprising:

[0008] An initial signal output by the brushless motor is collected using a three-phase circuit, and the initial signal is frequency divided. The initial signal records the operating parameters of the brushless motor in a first historical working period and a second historical working period;

[0009] The high-frequency signal after frequency division is accessed by an electronic speed regulator, the high-frequency signal is filtered twice in the electronic speed regulator to obtain a filtered signal, the filtered signal is subjected to Fourier transform to obtain a frequency domain signal, a first historical periodic modulation frequency and a second historical periodic modulation frequency are calculated based on the frequency domain signal, an optimized modulation frequency is calculated based on the first historical periodic modulation frequency and the second historical periodic modulation frequency, and a control signal corresponding to the optimized modulation frequency is output to the brushless motor.

[0010] According to the scheme, the high-frequency signal is filtered twice to optimize the signal, the optimized modulation frequency is calculated based on the first historical periodic modulation frequency and the second historical periodic modulation frequency in the historical data, and finally the control signal corresponding to the optimized modulation frequency is output. The scheme interacts with the data of the flight control through the Dshot protocol, and the operation unit in the electronic speed regulator finally generates a stable and pure filtered signal. The control signal output to the brushless motor reduces the operation noise of the brushless motor and ensures the stable and efficient operation of the brushless motor.

[0011] In some embodiments of the application, in the step of filtering the high-frequency signal twice in the electronic speed regulator to obtain a filtered signal, a low-pass filter and / or a dynamic notch filter is used to filter the high-frequency signal twice.

[0012] In some embodiments of the application, the step of calculating the first historical periodic modulation frequency and the second historical periodic modulation frequency based on the frequency domain signal by integration includes:

[0013] The operating parameters of the first historical working period and the second historical working period in the frequency domain signal are analyzed, and the operating parameters include voltage and current parameters at each time point in the first historical working period and the second historical working period.

[0014] The first instantaneous power of the first historical working period and the second instantaneous power of the second historical working period are calculated based on the operating parameters.

[0015] The best switching angle of the motor forward angle is calculated based on the number of magnetic poles of the motor.

[0016] The first historical periodic modulation frequency is calculated based on the best switching angle and the first instantaneous power, and the second historical periodic modulation frequency is calculated based on the best switching angle and the second instantaneous power.

[0017] In some embodiments of the application, in the step of calculating the first instantaneous power of the first historical working period and the second instantaneous power of the second historical working period based on the operating parameters, the first instantaneous power is calculated according to the following formula:

[0018] In some embodiments of the application, in the step of calculating the first instantaneous power of the first historical working period and the second instantaneous power of the second historical working period based on the operating parameters, the first instantaneous power is calculated according to the following formula:

[0019] The second instantaneous power is calculated according to the following formula:

[0020]

[0021] wherein and respectively represent the first instantaneous power and the second instantaneous power, and respectively represent the voltage parameter at the initial time point in the first historical working period and the second historical working period, and respectively represent the current parameter at the initial time point in the first historical working period and the second historical working period.

[0022] In some embodiments of the present application, in the step of calculating the optimal switching angle of the motor advance angle based on the number of magnetic poles of the motor, the optimal switching angle is calculated according to the following formula:

[0023] α = 360 / number of magnetic poles / 2;

[0024] wherein α represents the optimal switching angle.

[0025] In some embodiments of the present application, in the step of calculating the first historical period modulation frequency based on the optimal conversion angle and the first instantaneous power, the first historical period modulation frequency is calculated according to the following formula:

[0026]

[0027] wherein ΔF1 represents the first historical period modulation frequency, t1 and t2 respectively represent the starting time point and the ending time point of the first historical period, tn represents any time point in the first historical period, represents the first instantaneous power, P tn represents the brushless motor power value at the corresponding time of any time point in the first historical period, R tn represents the brushless motor speed value at the corresponding time of any time point in the first historical period, R τ represents the preset optimal speed value, f represents the preset adjustment frequency value, and α represents the optimal switching angle.

[0028] In some embodiments of the present application, in the step of calculating the second historical period modulation frequency based on the optimal conversion angle and the second instantaneous power, the second historical period modulation frequency is calculated according to the following formula:

[0029]

[0030] Wherein, ΔF2 represents the second historical period modulation frequency, t2 and t3 represent the starting time point and the ending time point of the second historical period respectively, tm represents any time point in the first historical period, represents the second instantaneous power, P tm represents the brushless motor power value corresponding to the time point of any time point in the second historical period, R tm represents the brushless motor speed value corresponding to the time point of any time point in the second historical period, R τ represents the preset optimal speed value, f represents the preset adjustment frequency value, and a represents the optimal switching angle.

[0031] In some embodiments of the application, the brushless motor speed value of each time point is calculated according to the following formula:

[0032] The brushless motor speed value = the motor kv value x the voltage value of the corresponding time point.

[0033] In some embodiments of the application, in the step of calculating the optimal modulation frequency based on the first historical period modulation frequency and the second historical period modulation frequency, the optimal modulation frequency is calculated according to the following formula:

[0034]

[0035] Wherein, B t represents the optimal modulation frequency, ΔF1 represents the first historical period modulation frequency, and ΔF2 represents the second historical period modulation frequency.

[0036] The application also provides a secondary filtering implementation system for a brushless motor electronic speed controller of a UAV, which comprises:

[0037] A frequency division module is configured to collect an initial signal output by the brushless motor through a three-phase circuit and perform frequency division on the initial signal, wherein the initial signal records the operation parameters of the brushless motor in a first historical working period and a second historical working period.

[0038] A frequency optimization module is configured to access the high-frequency signal after frequency division through an electronic speed regulator, perform secondary filtering on the high-frequency signal in the electronic speed regulator to obtain a filtered signal, perform Fourier transform on the filtered signal to obtain a frequency domain signal, calculate the first historical period modulation frequency and the second historical period modulation frequency based on the frequency domain signal, calculate the optimal modulation frequency based on the first historical period modulation frequency and the second historical period modulation frequency, and output a control signal corresponding to the optimal modulation frequency to the brushless motor.

[0039] Additional advantages, objects, and features of the application will be set forth in part by the description that follows, and will become apparent to those skilled in the art upon examination of the following detailed description and drawings in which illustrating the principles of the application. The objects and other advantages of the present application can be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

[0040] Those skilled in the art will appreciate that the objects and advantages of the application can be realized and attained by means summarized in the following detailed description, and can be realized and attained by the means pointed out in the appended claims. BRIEF DESCRIPTION OF DRAWINGS

[0041] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description, serve to explain the principles of the application.

[0042] Figure 1 A schematic diagram of an embodiment of the method for realizing secondary filtering of a brushless electric governor of a UAV;

[0043] Figure 2 A schematic diagram of the implementation process of the method for realizing secondary filtering of a brushless electric governor of a UAV;

[0044] Figure 3 A schematic diagram of the data processing step of the method for realizing secondary filtering of a brushless electric governor of a UAV. DETAILED DESCRIPTION

[0045] In order to make the objects, technical solutions and advantages of the present application clearer, the following will further describe the present application with reference to the embodiments and drawings. Herein, the illustrative embodiments of the present application and their descriptions are used to explain the present application, but are not used to limit the present application.

[0046] It should be noted that, in order to avoid the present application being obscured by unnecessary details, only the structures and / or processing steps closely related to the solutions according to the present application are shown in the drawings, and other details not closely related to the present application are omitted.

[0047] It should be emphasized that the terms "comprise / comprising" when used in this specification are taken to specify the presence of stated features, elements, steps or components but do not preclude the presence or addition of one or more other features, elements, steps, components, or groups thereof.

[0048] It should be noted that, unless otherwise specified, the term "connected" in this specification can not only mean direct connection, but also means indirect connection in the presence of an intermediate.

[0049] Prior art introduction:

[0050] 1. Currently, drones typically employ a flight control system, electronic speed controller (ESC), and motors. Most flight logic and functions are implemented in the flight control system, while the ESC only controls motor speed and doesn't effectively utilize monitoring data such as motor speed and current. Its internal functionality is relatively limited, and further adaptation is needed when combining ESCs and motors.

[0051] 2. An analysis of the existing ESC-supported protocols PWM and Dshot is conducted. The PWM protocol outputs analog signals, which are easily susceptible to interference during signal transmission. Furthermore, measuring a PWM pulse width typically involves hardware capturing the rising and falling edges of the signal to calculate the time difference. Due to the low clock accuracy of the receiving controller, the measured clock reference may deviate from the control terminal's. In contrast, the Dshot protocol uses digital transmission, offering superior interference resistance and data measurement accuracy compared to the PWM protocol.

[0052] In the following description, embodiments of the invention will be illustrated with reference to the accompanying drawings. In the drawings, the same reference numerals represent the same or similar parts, or the same or similar steps.

[0053] To solve the above problems, such as Figure 1 , 2 As shown in Figure 3, this invention proposes a method for implementing secondary filtering of a brushless ESC for unmanned aerial vehicles (UAVs). The steps of the method include:

[0054] Step S100: The initial signal output by the brushless motor is acquired using a three-phase circuit, and the initial signal is divided into frequencies. The initial signal contains the operating parameters of the brushless motor in the first historical working cycle and the second historical working cycle.

[0055] In some embodiments of the present invention, the operating parameters include the voltage and current parameters of the brushless motor at each time point in the first and second historical working cycles.

[0056] Step S200: The high-frequency signal after frequency division is received through the electronic speed controller. The high-frequency signal is filtered twice in the electronic speed controller to obtain a filtered signal. The filtered signal is Fourier transformed to obtain a frequency domain signal. The first historical period modulation frequency and the second historical period modulation frequency are calculated by integration based on the frequency domain signal. The optimized modulation frequency is calculated based on the first historical period modulation frequency and the second historical period modulation frequency. The control signal corresponding to the optimized modulation frequency is output to the brushless motor.

[0057] In some embodiments of the present application, the feedback information generated by the brushless motor contains high-frequency noise and low-frequency noise. According to the specifications and differences of the motor, the frequency of the noise is randomly distributed. The high-frequency signal is filtered by filtering to remove the distribution of high-frequency noise, and the generation of high-frequency noise during high-speed rotation of the motor is eliminated. The signal is then subjected to Fourier transform by the operation control unit, and the signal frequency is decomposed into different characteristic sinusoidal functions. The amplitude of the signal is smoothly transitioned because the peak part of the signal will interfere with the control of the motor. This process eliminates the peak part of the signal. At this time, the signal is not in a stable frequency state, and there is a small frequency difference in the low frequency range. The first historical period modulation frequency and the second historical period modulation frequency are calculated based on the frequency domain signal. The optimized modulation frequency is calculated based on the first historical period modulation frequency and the second historical period modulation frequency. The frequency time sequence is processed and adjusted. Finally, the optimized frequency control signal is output. The optimized control signal is input to the motor for control in the next control period, so that the noise level of the motor is reduced and the operation is more stable.

[0058] As shown in Figure 2 、 3 In some embodiments of the present application, the brushless motor inputs the control signal, analyzes the optimized modulation frequency corresponding to the control signal, and makes the brushless motor operate according to the optimized modulation frequency.

[0059] With the above scheme, the high-frequency signal is first filtered twice to optimize the signal, and then the optimized modulation frequency is calculated based on the first historical period modulation frequency and the second historical period modulation frequency in the historical data. The control signal corresponding to the optimized modulation frequency is finally output. The present application interacts with the data of the flight control through the Dshot protocol. The operation unit in the electronic speed controller finally generates a stable and pure secondary filtered signal. The output control signal is output to the brushless motor to reduce the operating noise of the brushless motor and ensure stable and efficient operation of the brushless motor.

[0060] In some embodiments of the present application, in the step of filtering the high-frequency signal twice in the electronic speed controller to obtain a filtered signal, a low-pass filter and / or a dynamic notch filter is used to filter the high-frequency signal twice.

[0061] In some embodiments of the present application, the filtering mode of the secondary filtering can be realized by a low-pass filter and / or a dynamic notch filter.

[0062] Low-pass filter implementation: a. Change the PT1 implementation algorithm based on the existing Biquad filter; b. Increase the cutoff frequency of the low-pass filter; c. Set the cutoff frequency to 0 to disable the entire filter bank;

[0063] Dynamic notch filter implementation: a. Set the highest cut-off frequency of the gyro dynamic low-pass filter; b. Use the RPM filter configuration fragment to reconfigure the dynamic notch filter to a single; c. Reduce the center frequency by the motor resonance noise peak, reduce the filter delay.

[0064] With the above scheme, the scheme filters high-frequency signals through filtering, removes the distribution of high-frequency noise, and first eliminates the generation of high-frequency noise during high-speed rotation of the motor.

[0065] In some embodiments of the present application, the step of calculating the first historical cycle modulation frequency and the second historical cycle modulation frequency based on the frequency domain signal includes:

[0066] Analyzing the operating parameters of the first historical working cycle and the second historical working cycle in the frequency domain signal, the operating parameters including voltage and current parameters at each time point in the first historical working cycle and the second historical working cycle;

[0067] Calculating the first instantaneous power of the first historical working cycle and the second instantaneous power of the second historical working cycle based on the operating parameters;

[0068] Calculating the optimal switching angle of the motor advance angle based on the number of magnetic poles of the motor;

[0069] Calculating the first historical cycle modulation frequency based on the optimal switching angle and the first instantaneous power, and calculating the second historical cycle modulation frequency based on the optimal switching angle and the second instantaneous power.

[0070] With the above scheme, since the brushless motor uses alternating current, the optimal switching angle needs to be calculated, and in the process of calculating the first historical cycle modulation frequency and the second historical cycle modulation frequency, the present application ensures the accuracy of the calculated first historical cycle modulation frequency and the second historical cycle modulation frequency based on power and optimal switching angle, which is convenient for calculating the optimal optimization modulation frequency in the subsequent steps.

[0071] In some embodiments of the present application, in the step of calculating the first instantaneous power of the first historical working cycle and the second instantaneous power of the second historical working cycle based on the operating parameters, the first instantaneous power is calculated according to the following formula:

[0072]

[0073] The second instantaneous power is calculated according to the following formula:

[0074]

[0075] Wherein And respectively represent a first instantaneous power and a second instantaneous power, and respectively represent a voltage parameter at an initial time point in a first historical working period and a second historical working period, and respectively represent a current parameter at an initial time point in a first historical working period and a second historical working period.

[0076] In some embodiments of the present application, the initial time point in the first historical working period and the second historical working period is the starting time of the first historical working period or the second historical working period.

[0077] In some embodiments of the present application, in the step of calculating the optimal switching angle of the motor advance angle based on the number of magnetic poles of the motor, the optimal switching angle is calculated according to the following formula:

[0078] α = 360 / number of magnetic poles / 2;

[0079] wherein, α represents the optimal switching angle.

[0080] In some embodiments of the present application, the brushless motor for the unmanned aerial vehicle generally has 12 or 14 magnetic poles, and the number of magnetic poles can be 12, if the number of magnetic poles is 12, then the calculated optimal switching angle is 15°.

[0081] By using the above scheme, the optimal switching angle of the motor is related to the number of magnetic poles of the motor, and the optimal switching angle can be accurately calculated.

[0082] In some embodiments of the present application, in the step of calculating the first historical period modulation frequency based on the optimal conversion angle and the first instantaneous power, the first historical period modulation frequency is calculated according to the following formula:

[0083]

[0084] wherein, ΔF1 represents the first historical period modulation frequency, t1 and t2 respectively represent the starting time point and the ending time point of the first historical period, tn represents any time point in the first historical period, represents the first instantaneous power, P tn represents the brushless motor power value at the corresponding time of any time point in the first historical period, R tn represents the brushless motor speed value at the corresponding time of any time point in the first historical period, R τ represents the preset optimal speed value, f represents the preset adjustment frequency value, and α represents the optimal switching angle.

[0085] In some embodiments of the present application, in the step of calculating the second historical period modulation frequency based on the optimal switching angle and the second instantaneous power, the second historical period modulation frequency is calculated according to the following formula:

[0086]

[0087] wherein, ΔF2 represents the second historical period modulation frequency, t2 and t3 represent the starting time point and the ending time point of the second historical period respectively, tm represents any time point in the first historical period, represents the second instantaneous power, P tm represents the brushless motor power value at the corresponding time of any time point in the second historical period, R tm represents the brushless motor speed value at the corresponding time of any time point in the second historical period, R τ represents the preset optimal speed value, f represents the preset adjustment frequency value, and a represents the optimal switching angle.

[0088] In the specific implementation process, the adjustment frequency is passed as a fixed value, which is generally 24 kHz, 48 kHz or 96 kHz. 24 kHz is used for 16-bit electric adjustment, and 48 kHz and 96 kHz are recommended for 32-bit electric adjustment. The larger the frequency, the more precise the frequency timing processing, but the more single-chip computer computing resources are occupied. Generally, 48 kHz is the most optimal, and the adjustment frequency value can be preset to 48000.

[0089] In the specific implementation process, the preset optimal speed value is generally the motor speed of the unmanned aerial vehicle measured during hovering, and in the present scheme, the optimal speed value can be preset to 25000.

[0090] By using the above scheme, the preset calculation parameters are accurately set, and the accurate calculation of the first historical period modulation frequency and the second historical period modulation frequency is ensured.

[0091] In some embodiments of the present application, the brushless motor speed value of each time point is calculated according to the following formula:

[0092] The brushless motor speed value = motor kv value x voltage value of the corresponding time point.

[0093] In the specific implementation process, the motor kv value is the self parameter of the brushless motor, and the motor kv value is defined as the speed / v, which means that the input voltage increases by 1 volt, and the motor idle speed increases by the speed value kv multiplied by the voltage, which is equal to the number of revolutions per minute of the motor.

[0094] By using the above scheme, the voltage value of each time point is brought into the above formula, and the brushless motor speed value of each time point is accurately calculated.

[0095] In some embodiments of the present application, in the step of calculating the optimized modulation frequency based on the first historical periodic modulation frequency and the second historical periodic modulation frequency, the optimized modulation frequency is calculated according to the following formula:

[0096]

[0097] Wherein, B t represents the optimized modulation frequency, Delta F1 represents the first historical periodic modulation frequency, and Delta F2 represents the second historical periodic modulation frequency.

[0098] In the specific implementation process, the calculated optimized modulation frequency is used to modulate the feedback signal input by the frequency modulation circuit integrated in the single-chip microcomputer, and finally an output control signal is output; through the Dshot protocol and the data interaction with the flight control, the operation unit in the electronic speed controller finally generates a stable and pure control signal, and the output control signal is output to the brushless motor to drive the motor to rotate stably and efficiently.

[0099] As Figure 2 shown, in the specific implementation process, the single-chip microcomputer used in the electronic speed regulator in the present scheme can be an ESP32 or an STM32 series single-chip microcomputer. Through processing of high-frequency signals after frequency division, the main processing is completed in the single-chip microcomputer unit integrated in the electronic speed controller.

[0100] The present scheme realizes the motor secondary filtering process in the electronic speed controller of the unmanned aerial vehicle. Real-time motor speed data is collected synchronously through the Dshot protocol, core code is added to the electronic speed controller firmware, the calculation capability of the single-chip microcomputer in the electronic speed controller is used to realize secondary filtering of high-frequency signals in the motor conduction process, and the filtered control signal is output to the motor, so that the motor noise level and rotation efficiency are improved.

[0101] Dshot protocol signal transmission: enables the flight control to receive accurate RPM feedback on the electronic speed controller signal line of each motor. This function does not require additional electronic speed controller telemetry signal lines or additional reverse telemetry channels. The last content of each Dshot command frame sent from the flight control will add a command, which will request the real-time eRPM sensor reading from the electronic speed controller. Only the number of motor poles needs to be set, so that the eRPM can be converted into RPM data of the motor speed.

[0102] The present patent technology realizes the speed monitoring of the motor through the mature Dshot protocol, reduces the high-frequency vibration generated by the brushless motor during high-speed rotation through the secondary filtering of the electronic speed controller, and thus reduces the vibration noise caused by the paddle and the motor body.

[0103] By monitoring the motor speed, high frequency monitoring motor step rotation angle, adjusting the signal frequency of the electronic speed controller to control the opening time of the current, thereby realizing the smaller motor current consumption, the heating condition of the motor coil is reduced, the energy consumption of the battery during the flight of the unmanned aerial vehicle is saved, and longer flight time is provided under the condition of the same output power.

[0104] The beneficial effects of the present scheme include:

[0105] 1、The present scheme only needs to add a simple cost control hardware of a single-chip microcomputer in the cost control aspect, optimizes the transmission efficiency of the motor by adding a function in the hardware of the electronic speed controller itself, reduces the operation pressure of the flight control, unlike the brushless motor system with feedback, no additional telemetry wiring is needed between the motor and the electronic speed controller, and the feedback data can be transmitted synchronously in the power supply line connected with the three-phase motor, the modification cost is low, and it is also convenient to integrate the electronic speed controller product in the production and manufacturing process;

[0106] 2、In combination with the performance of the electronic speed controller with secondary filtering in work, the high-frequency vibration in the rotation process of the paddle and the motor is reduced, thereby realizing the reduction of the generation of high-frequency noise, through actual power-on test and detection, the vibration noise of the 2206 type motor matched with the 5024 type paddle can be reduced by 10%, the inner rotor coil reduces the heating condition, and the single motor reduces 2-3 ampere current under 50% throttle voltage, the ascending power value can be increased by 0.3-0.6, and the endurance time of the battery is effectively increased;

[0107] 3、Through the single-chip microcomputer operation unit embedded in the brushless electronic speed controller, high-frequency signal secondary filtering operation is added, high-efficiency matching of the electronic speed controller motor can be realized, the single-chip microcomputer operation module can complete the interaction of the Dshot protocol with the flight control, and also can complete the self-operation of the functions such as filtering and optimization of the electronic speed controller, the integrated processing and control feedback of the motor speed feedback are realized, and the motor secondary filtering operation process is realized through the brush writing of the electronic speed controller firmware.

[0108] The embodiment of the present application also provides a secondary filtering implementation device of a brushless electronic speed controller of an unmanned aerial vehicle, which comprises a computer device, the computer device comprises a processor and a memory, the memory stores computer instructions, and the processor is used for executing the computer instructions stored in the memory.

[0109] The embodiment of the present application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps of the secondary filtering implementation method of the brushless electronic governor of the unmanned aerial vehicle. The computer readable storage medium can be a tangible storage medium, such as a random access memory (RAM), a memory, a read only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a floppy disk, a hard disk, a removable storage disk, a CD-ROM, or any other form of storage medium known in the technical field.

[0110] Those of ordinary skill in the art will appreciate that the various illustrative components, systems and methods described in connection with the embodiments disclosed herein can be implemented as hardware, software, or a combination thereof. The choice of hardware or software implementation is a matter of design choice and will depend on the particular application and constraints of the design. Those of skill in the art will be able to make such design choices without departing from the scope of the present application. Aspects of the application can be implemented in hardware, for example, as an electronic circuit, as an application specific integrated circuit (ASIC), as a firmware, as a plug-in, as a functional card, etc. Aspects of the application can also be implemented in software, for example, as a program or code segment. The program or code segment can be stored in a machine readable medium, or transmitted through a carrier wave in a transmission medium or communication link.

[0111] It is to be understood that the application is not limited to the particular configurations and processes described herein and shown in the drawings, which are provided by way of example only. Detailed descriptions of known methods are omitted so as not to obscure the description of the present application. In the above-described embodiments, several specific steps are described and illustrated as examples. However, the methods process of the present application is not limited to the specific steps described and illustrated, and one of skill in the art will be able to make various changes, modifications and additions, or change the order of the steps, after having the benefit of this description.

[0112] In the present application, features described and / or illustrated in relation to one embodiment can be used in the same or a similar way in one or more other embodiments, and / or combined with or instead of features of other embodiments.

[0113] The above description is merely illustrative of the application, and is not intended to limit the application. The embodiments of the application can be variously changed and modified without departing from the spirit and scope of the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the scope of the application.

Claims

1. A method for implementing secondary filtering of a brushless electronic governor of a UAV, characterized in that, The steps of the method comprise: An initial signal output by the brushless motor is collected by a three-phase circuit, and the initial signal is frequency-divided, wherein the initial signal records operation parameters of the brushless motor in a first historical working period and a second historical working period; A high-frequency signal after frequency division is accessed by an electronic governor, the high-frequency signal is twice filtered in the electronic governor to obtain a filtered signal, the filtered signal is subjected to Fourier transform to obtain a frequency domain signal, a first historical period modulation frequency and a second historical period modulation frequency are calculated based on the frequency domain signal, operation parameters of the first historical working period and the second historical working period in the frequency domain signal are analyzed, the operation parameters comprise voltage and current parameters at each time point in the first historical working period and the second historical working period, a first instantaneous power of the first historical working period and a second instantaneous power of the second historical working period are calculated based on the operation parameters, an optimal switching angle of a motor advance angle is calculated based on the number of magnetic poles of the motor, the first historical period modulation frequency is calculated based on the optimal switching angle and the first instantaneous power, and the first historical period modulation frequency is calculated according to the following formula: wherein, represents a first historical period modulation frequency, and respectively represent a starting time point and an ending time point of the first historical period, represents any one time point in the first historical period, represents a first instantaneous power, represents a brushless motor power value corresponding to the time point of any one time point in the first historical period, represents a brushless motor speed value corresponding to the time point of any one time point in the first historical period, represents a preset optimal speed value, represents a preset adjustment frequency value, represents an optimal switching angle; The second historical period modulation frequency is calculated based on the optimal switching angle and the second instantaneous power, and the second historical period modulation frequency is calculated according to the following formula: wherein, denotes a second historical periodic modulation frequency, denotes an end time point of the second historical period, denotes any one time point in the first historical period, denotes a second instantaneous power, denotes a brushless motor power value corresponding to the time point of any one time point in the second historical period, denotes a brushless motor speed value corresponding to the time point of any one time point in the second historical period; An optimized modulation frequency is calculated based on the first historical period modulation frequency and the second historical period modulation frequency, and the optimized modulation frequency is calculated according to the following formula: wherein, represents an optimized modulation frequency, represents a first historical periodic modulation frequency, represents a second historical periodic modulation frequency; A control signal corresponding to the optimized modulation frequency is output to the brushless motor.

2. The method of claim 1, wherein, In the step of twice filtering the high-frequency signal in the electronic governor to obtain the filtered signal, a low-pass filter and / or a dynamic notch filter are used to twice filter the high-frequency signal.

3. The method of claim 1, wherein, In the step of calculating the first instantaneous power of the first historical working period and the second instantaneous power of the second historical working period based on the operation parameters, the first instantaneous power is calculated according to the following formula: The second instantaneous power is calculated according to the following formula: wherein and respectively represent the first and second instantaneous power, and respectively represent the voltage parameter at the initial time point in the first and second historical duty cycles, and respectively represent the current parameter at the initial time point in the first and second historical duty cycles.

4. The method of claim 1, wherein, In the step of calculating the optimal switching angle of the motor advance angle based on the number of magnetic poles of the motor, the optimal switching angle is calculated according to the following formula: = 360 / number of poles / 2; wherein represents the optimal switching angle.

5. The method of claim 1, wherein, The brushless motor speed value at each time point is calculated according to the following formula: Brushless motor rotation speed value = motor kv value Voltage value at corresponding time point.

6. A secondary filtering implementation system for a brushless electronic governor of a UAV, characterized in that, The system comprises: A frequency division module is configured to collect an initial signal output by the brushless motor by a three-phase circuit, and frequency-divides the initial signal, wherein the initial signal records operation parameters of the brushless motor in a first historical working period and a second historical working period; The frequency optimization module is configured to access the high-frequency signal after frequency division through an electronic governor, perform secondary filtering on the high-frequency signal to obtain a filtered signal, perform Fourier transform on the filtered signal to obtain a frequency domain signal, calculate a first historical periodic modulation frequency and a second historical periodic modulation frequency based on the frequency domain signal, analyze operation parameters of the first historical working period and the second historical working period in the frequency domain signal, wherein the operation parameters include voltage and current parameters at each time point in the first historical working period and the second historical working period, calculate a first instantaneous power of the first historical working period and a second instantaneous power of the second historical working period based on the operation parameters, calculate an optimal switching angle of a motor advance angle based on the number of magnetic poles of the motor, calculate the first historical periodic modulation frequency based on the optimal switching angle and the first instantaneous power, and calculate the first historical periodic modulation frequency according to the following formula: wherein, denotes a first historical period modulation frequency, and denote a first historical period start time point and a first historical period end time point, respectively, denotes any one time point in the first historical period, denotes a first instantaneous power, denotes a brushless motor power value corresponding to the time point of any one time point in the first historical period, denotes a brushless motor speed value corresponding to the time point of any one time point in the first historical period, denotes a preset optimal speed value, denotes a preset adjustment frequency value, denotes an optimal switching angle; calculate the second historical periodic modulation frequency based on the optimal switching angle and the second instantaneous power, and calculate the second historical periodic modulation frequency according to the following formula: wherein, denotes a second historical periodic modulation frequency, denotes an end time point of the second historical period, denotes any one time point in the first historical period, denotes a second instantaneous power, denotes a brushless motor power value corresponding to the time point of any one time point in the second historical period, denotes a brushless motor speed value corresponding to the time point of any one time point in the second historical period; calculate an optimized modulation frequency based on the first historical periodic modulation frequency and the second historical periodic modulation frequency, and calculate the optimized modulation frequency according to the following formula: wherein, represents an optimized modulation frequency, represents a first historical periodic modulation frequency, represents a second historical periodic modulation frequency, and outputs a control signal corresponding to the optimized modulation frequency to the brushless motor.

Images