Calibration method and device of accelerometer in unmanned aerial vehicle and electronic equipment

Abstract

The application provides a method and device for calibrating an accelerometer in a UAV and an electronic device, comprising: determining a reference acceleration corresponding to the UAV according to each tilt angle; collecting at least one measured acceleration corresponding to the UAV by the accelerometer when the UAV is placed at the tilt angle; and calibrating the accelerometer according to the reference acceleration and the measured acceleration. The application can reduce the influence of human factors on the calibration process of the accelerometer and significantly improve the calibration accuracy of the accelerometer.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of accelerometer, in particular to a calibration method and device of an accelerometer in a UAV and an electronic device. BACKGROUND

[0002] The accelerometer is the most important inertial sensor of the UAV and is also the basis for algorithm fusion of the navigation system. The error sources of the accelerometer include noise, scale factor and axis offset. In general, the manufacturer will perform high-precision factory calibration on the accelerometer, so that the main factor affecting the measurement accuracy of the accelerometer is the installation position. At present, the accelerometer is generally integrated on the IMU component, and there are two types of on-board and external. The ideal installation position of the IMU is the geometric center of the UAV. Limited by the installation precision of the artificial, the installation position of the accelerometer must be calibrated before the UAV is shipped.

[0003] At present, the calibration process of the accelerometer of the UAV generally adopts a six-face static calibration method (such as a six-face box method and a manual six-face static method). The six-face box method cannot adapt to UAVs of different models, and the cost of manufacturing a cuboid is relatively high. Although the manual six-face static method can adapt to different models, it is difficult to ensure that the adjacent two faces are strictly perpendicular by manual operation, and it is difficult to ensure that the UAV is truly static for a period of time by hand, so that the calibrated accelerometer still has the problem of poor accuracy. SUMMARY

[0004] Therefore, the present application aims to provide a calibration method and device of an accelerometer in a UAV and an electronic device, which can reduce the influence of human factors on the calibration process of the accelerometer and significantly improve the calibration accuracy of the accelerometer.

[0005] In a first aspect, an embodiment of the present application provides a calibration method of an accelerometer in a UAV, the UAV being placed statically at a plurality of inclination angles on a preset test table, the UAV being provided with an accelerometer, comprising: determining a reference acceleration corresponding to the UAV according to each inclination angle; collecting at least one measured acceleration corresponding to the UAV by the accelerometer when the UAV is placed statically at the inclination angle; and calibrating the accelerometer according to the reference acceleration and the measured acceleration.

[0006] In one embodiment, the step of calibrating the accelerometer based on the reference acceleration and the measured acceleration includes: identifying the inclination angle corresponding to each measured acceleration based on the extreme value of each measured acceleration; determining the mean acceleration corresponding to each inclination angle based on the measured acceleration corresponding to each inclination angle; and determining the target error model corresponding to the accelerometer based on the reference acceleration and the mean acceleration corresponding to each inclination angle, so as to calibrate the accelerometer based on the accelerometer error model.

[0007] In one embodiment, the step of determining the target error model corresponding to the accelerometer based on the reference acceleration and the mean acceleration corresponding to each of the tilt angles includes: obtaining an initial error model corresponding to the accelerometer; fitting a parameter solution equation corresponding to the initial error model using the least squares method, and performing an inverse operation on the high-dimensional matrix in the parameter solution equation using the Gauss-Jordan elimination method to obtain target model parameters; and updating the initial error model based on the target model parameters to obtain the target error model corresponding to the accelerometer.

[0008] In one embodiment, after the step of calibrating the accelerometer according to the reference acceleration and the measured acceleration, the method further includes: collecting the acceleration to be calibrated corresponding to the drone through the accelerometer; filtering the acceleration to be calibrated, and updating the filtered acceleration to be calibrated through the target error model to obtain the calibrated acceleration corresponding to the drone.

[0009] In one embodiment, the tilt angle includes a horizontal angle, a first tilt angle, and a second tilt angle, and the plane where the horizontal angle is located, the plane where the first tilt angle is located, and the plane where the second tilt angle is located are perpendicular to each other.

[0010] In one embodiment, the drone is provided with a drone support part, a drone left arm, a drone right arm, a drone head and a drone tail, the first tilt angle includes a left tilt angle and / or a right tilt angle, and the second tilt angle includes a front tilt angle and / or a rear tilt angle; before the step of determining the reference acceleration corresponding to the drone according to each of the tilt angles, the method further includes: determining the left tilt angle according to the relative position relationship between the drone support part and the drone left arm; and determining the right tilt angle according to the relative position relationship between the drone support part and the drone right arm; and determining the front tilt angle according to the relative position relationship between the drone support part and the drone head; and determining the rear tilt angle according to the relative position relationship between the drone support part and the drone tail.

[0011] In one embodiment, the step of determining the reference acceleration corresponding to the drone according to each of the tilt angles includes: obtaining the horizontal gravitational acceleration corresponding to the horizontal angle; determining the left gravitational acceleration corresponding to the left tilt angle, the right gravitational acceleration corresponding to the right tilt angle, the front gravitational acceleration corresponding to the front tilt angle, and the rear gravitational acceleration corresponding to the rear tilt angle based on the horizontal gravitational acceleration and a preset coordinate system conversion matrix; and obtaining the reference acceleration corresponding to the drone according to the horizontal neutral acceleration, the left gravitational acceleration, the right gravitational acceleration, the front gravitational acceleration, and the rear gravitational acceleration.

[0012] In a second aspect, an embodiment of the present invention further provides a calibration device for an accelerometer in a drone, wherein the drone is placed stationary at multiple inclination angles on a preset test bench, and the drone is provided with an accelerometer, comprising: a reference acceleration determination module, for determining a reference acceleration corresponding to the drone according to each of the inclination angles; a measured acceleration acquisition module, for acquiring at least one measured acceleration corresponding to the drone through the accelerometer when the drone is placed stationary at the inclination angle; and a calibration module, for calibrating the accelerometer according to the reference acceleration and the measured acceleration.

[0013] In a third aspect, an embodiment of the present invention further provides an electronic device, comprising a processor and a memory, wherein the memory stores computer-executable instructions that can be executed by the processor, and the processor executes the computer-executable instructions to implement any one of the methods provided in the first aspect.

[0014] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions. When the computer-executable instructions are called and executed by a processor, the computer-executable instructions prompt the processor to implement any one of the methods provided in the first aspect.

[0015] The embodiment of the present application provides a calibration method and device of an accelerometer in a UAV and an electronic device, the UAV is placed at a plurality of tilt angles on a preset test table, the UAV is provided with an accelerometer, first, a reference acceleration corresponding to the UAV is determined according to each tilt angle, then at least one measured acceleration corresponding to the UAV is collected by the accelerometer when the UAV is placed at the tilt angle, and finally the accelerometer is calibrated according to the reference acceleration and the measured acceleration. The above method calculates the corresponding reference acceleration based on the tilt angle of the UAV, collects the measured acceleration by the accelerometer when the UAV is placed at the tilt angle, and thus calibrates the accelerometer according to the reference acceleration and the measured acceleration, so that the influence of human factors on the calibration process of the accelerometer can be reduced, and the calibration accuracy of the accelerometer can be significantly improved.

[0016] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application will be realized and achieved by the structure particularly pointed out in the description, claims and drawings.

[0017] In order to make the above-mentioned purposes, characteristics and advantages of the present application more obvious and easy to understand, the following preferred embodiments are specifically described below, and the accompanying drawings are described in detail as follows. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0019] Figure 1 A flowchart of a calibration method of an accelerometer in a UAV provided by the embodiment of the present application is shown in the figure;

[0020] Figure 2 A calibration effect comparison schematic diagram provided by the embodiment of the present application is shown in the figure;

[0021] Figure 3 A calibration effect comparison schematic diagram under a horizontal angle provided by the embodiment of the present application is shown in the figure;

[0022] Figure 4 A structure schematic diagram of a calibration device of an accelerometer in a UAV provided by the embodiment of the present application is shown in the figure;

[0023] Figure 5 A structure schematic diagram of an electronic device provided by the embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0025] Currently, the calibration process for drone accelerometers mostly uses the six-sided static calibration method. This method uses the six faces of a rectangular parallelepiped as a reference. It requires the drone to be horizontal, inverted, and rotated nose-up, nose-down, left-side-up, and left-side-down, with a period of rest in each direction. This is challenging to implement, and the exact perpendicularity of two adjacent faces directly affects calibration accuracy. The most accurate calibration method currently is the six-sided box method: A reference plane is set, the drone is fixed in a rectangular parallelepiped, and the rectangular parallelepiped is rotated while all six faces remain stationary on the reference plane for a period of time. However, its disadvantages are that it is not adaptable to different drone models, and the cost of manufacturing the rectangular parallelepiped is high. The most widely used calibration method is the manual six-sided static method: a reference plane is set, and the six faces of the drone are manually rotated while remaining stationary on the reference plane for a period of time. While this method can be adapted to different drone models, it is difficult to ensure the exact perpendicularity of two adjacent faces manually, and it is difficult to keep the drone stationary for a period of time when hand-held, resulting in poor accuracy.

[0026] Based on this, the present invention provides a calibration method, device and electronic equipment for an accelerometer in a drone, which can reduce the impact of human factors on the accelerometer calibration process and significantly improve the calibration accuracy of the accelerometer.

[0027] To facilitate understanding of this embodiment, a calibration method for an accelerometer in a drone disclosed in an embodiment of the present invention is first described in detail. The drone is placed stationary at multiple tilt angles on a preset test bench. The drone is provided with an accelerometer. Figure 1 The flowchart of a method for calibrating an accelerometer in a drone is shown, and the method mainly includes the following steps S102 to S106:

[0028] In step S102, a reference acceleration corresponding to the unmanned aerial vehicle is determined according to each tilt angle. The reference acceleration is calculated based on the local gravitational acceleration, and the tilt angle is the angle between the tilt reference surface and the horizontal surface. The tilt angle is related to the hardware structure of the unmanned aerial vehicle. For example, the unmanned aerial vehicle is placed on a horizontal test platform with the support part (such as a leg) and the left arm of the unmanned aerial vehicle as the fulcrum. The angle between the left tilt reference surface and the horizontal surface (i.e., the left tilt angle) can be determined based on the size parameters of the support part and the size parameters of the left arm of the unmanned aerial vehicle. The tilt process does not require manual support of the unmanned aerial vehicle. In an embodiment, the gravitational acceleration of the unmanned aerial vehicle at each tilt angle can be determined, and the gravitational acceleration at each tilt angle can be used as the reference acceleration.

[0029] In step S104, at least one measured acceleration corresponding to the unmanned aerial vehicle is collected by the accelerometer when the unmanned aerial vehicle is placed at the tilt angle. The measured acceleration is the acceleration collected by the accelerometer before calibration. For example, the unmanned aerial vehicle is placed on a horizontal test platform with the support part (such as a leg) and the left arm of the unmanned aerial vehicle as the fulcrum, i.e., the unmanned aerial vehicle is placed at the left tilt angle. The unmanned aerial vehicle is placed at rest for a predetermined time (such as 5 seconds). During the predetermined time, multiple measured accelerations are collected by the accelerometer.

[0030] In step S106, the accelerometer is calibrated according to the reference acceleration and the measured acceleration. In an embodiment, a target error model corresponding to the accelerometer can be determined according to the reference acceleration and the measured acceleration corresponding to each tilt angle. The acceleration collected by the accelerometer is calibrated based on the target error model to improve the accuracy of the acceleration output by the accelerometer.

[0031] The calibration method for the accelerometer in the unmanned aerial vehicle provided by the embodiment of the present application calculates the corresponding reference acceleration based on the tilt angle of the unmanned aerial vehicle, collects the measured acceleration by the accelerometer when the unmanned aerial vehicle is placed at rest at the tilt angle, and calibrates the accelerometer according to the reference acceleration and the measured acceleration. The embodiment of the present application can not only reduce the influence of human factors on the calibration process of the accelerometer, but also significantly improve the calibration accuracy of the accelerometer.

[0032] In one embodiment, the tilt angle includes a horizontal angle, a first tilt angle, and a second tilt angle, and the planes containing the horizontal angle, the first tilt angle, and the second tilt angle are perpendicular to each other. In a specific embodiment, the drone is provided with a drone support, a drone left arm, a drone right arm, a drone head, and a drone tail. The first tilt angle includes a left tilt angle and / or a right tilt angle, and the second tilt angle includes a front tilt angle and / or a rear tilt angle. For example, when the drone is tilted on a horizontal test platform with the drone support (such as a leg) and the drone left arm as fulcrums, the drone is placed at a left tilt angle; when the drone is tilted on the horizontal test platform without the drone support and the drone right arm as fulcrums, the drone is placed at a right tilt angle; when the drone is tilted on the horizontal test platform without the drone support and the drone head as fulcrums, the drone is placed at a front tilt angle; when the drone is tilted on the horizontal test platform without the drone support and the drone tail as fulcrums, the drone is placed at a rear tilt angle.

[0033] Based on the above embodiment, the embodiment of the present invention provides an implementation method for determining the tilt angle, specifically: (1) determining the left tilt angle based on the relative position relationship between the drone support part and the left arm of the drone; (2) determining the right tilt angle based on the relative position relationship between the drone support part and the right arm of the drone; (3) determining the front tilt angle based on the relative position relationship between the drone support part and the head of the drone; (4) determining the rear tilt angle based on the relative position relationship between the drone support part and the tail of the drone. For ease of understanding, the embodiment of the present invention takes the left tilt angle as an example. When the drone is placed at a left tilt angle, the drone support part, the drone left arm and the drone geometric center form a triangle. Based on the size parameters of the drone support part, the size parameters of the drone left arm and the position of the drone geometric center, the left tilt angle can be calculated. The calculation process of the right tilt angle, the front tilt angle and the rear tilt angle can all refer to the calculation process of the left tilt angle mentioned above, and the embodiment of the present invention will not elaborate on this. Optionally, the above size parameters can all be obtained from the drone design drawings, or by manually measuring the size parameters of each structure.

[0034] A three-axis accelerometer is an inertial measurement unit that measures the specific force of an object. When the accelerometer remains stationary, it can sense the acceleration due to gravity. This is the basic principle of accelerometer calibration. Based on this, an embodiment of the present invention also provides an implementation method for determining the reference acceleration corresponding to the drone based on each tilt angle, as shown in steps a to c below:

[0035] Step a: Obtain the horizontal gravity acceleration corresponding to the horizontal angle. For example, five reference planes of the quadrotor drone are selected: the horizontal angle, the left tilt angle β1, the right tilt angle β2, the front tilt angle β3, and the rear tilt angle β4. The horizontal gravity acceleration is recorded as a0 = [0 0 g] T , g is the local acceleration of gravity.

[0036] Step b, based on the horizontal gravity acceleration and the preset coordinate system conversion matrix, respectively determine the left gravity acceleration corresponding to the left tilt angle, the right gravity acceleration corresponding to the right tilt angle, the front gravity acceleration corresponding to the front tilt angle, and the rear gravity acceleration corresponding to the rear tilt angle. In one embodiment, the gravity acceleration at a certain tilt angle is Represents the transformation matrix from the Earth-fixed coordinate system to the body coordinate system (that is, the above coordinate system transformation matrix):

[0037]

[0038] Among them, θ ref and φ ref is the reference pitch angle and the reference roll angle. In the specific implementation, the relationship between the tilt angle and the reference Euler angle is: when tilting left, θ ref =0,φ ref =-β1, when leaning to the right ref =0,φ ref =β2, θ when leaning forward ref =-β3,φ ref =0, when tilted backward θ ref =β4,φ ref =0.

[0039] Step c, according to the horizontal neutral acceleration, left gravity acceleration, right gravity acceleration, front gravity acceleration and rear gravity acceleration, obtain the reference acceleration corresponding to the drone. For example, the reference acceleration is recorded as

[0040] Regarding the aforementioned step S106, the embodiment of the present invention further provides an implementation method for calibrating the accelerometer according to the reference acceleration and the measured acceleration, as shown in steps 1 to 3 below:

[0041] Step 1: Identify the tilt angle corresponding to each measured acceleration based on the extreme value of each measured acceleration. By setting the tilt angle corresponding to each measured acceleration, workers can disregard the order in which the tilt angles are placed when placing the drone, thereby reducing their workload.

[0042] Step 2: Determine the mean acceleration corresponding to each tilt angle based on the measured acceleration corresponding to each tilt angle. For example, place the drone on a test bench and record multiple measured accelerations at four tilt angles when it is stationary for 5 seconds. For each tilt angle, calculate the mean acceleration corresponding to the tilt angle based on the multiple measured accelerations corresponding to the tilt angle. This removes noise from the measurement process.

[0043] Step 3: Based on the reference acceleration and the mean acceleration corresponding to each tilt angle, determine the target error model corresponding to the accelerometer, and calibrate the accelerometer based on the accelerometer error model. For details, see steps 3.1 to 3.3 below:

[0044] Step 3.1, obtain the initial error model corresponding to the accelerometer. The actual measurement output of the triaxial accelerometer is α0 = [a 0x a 0y a 0z ] T Since the accelerometer is very sensitive to vibration, it is filtered before calibration to obtain a f =[a fx a fy a fz ] T , the initial error model is as follows:

[0045] a=Ma f +B,

[0046] Among them, M represents the slight tilt caused by the installation error, B represents the installation offset, and K xx , K yy , K zz is the three-axis calibration factor difference, δ xy , δ xz , δ yx , δ yz , δ zx , δ zy is the three-axis non-orthogonality error. In order to calibrate the accelerometer, the following 12 unknown model parameters need to be estimated:

[0047] Θ=[K xx δ xy δ xz δ yx K yy δ yz δ zx δ zy K zz B x B y B z ] T.

[0048] Step 3.2: Use the least squares method to fit the parameter solution equation corresponding to the initial error model, and use the Gauss-Jordan elimination method to invert the high-dimensional matrix in the parameter solution equation to obtain the target model parameters. In one embodiment, based on the above initial error model, the following optimization equation is established:

[0049] k is the number of tilt angles.

[0050] Currently, optimization algorithms for accelerometer calibration include the least squares method, the LM optimization algorithm, and the ellipsoid fitting algorithm. Both the LM optimization algorithm and the ellipsoid fitting algorithm target the modulus of the specific force and are not optimal solutions. The least squares method is the optimal unbiased estimate, but its disadvantage is that it requires a large amount of computation when there are too many estimated parameters. Using the Gauss-Jordan elimination method for high-dimensional matrix inversion can significantly reduce the computational complexity. The optimal least squares estimate of the accelerometer calibration parameters is:

[0051]

[0052] in,

[0053]

[0054]

[0055] In step 3.3, the initial error model is updated based on the target model parameters to obtain the target error model corresponding to the accelerometer.

[0056] After the accelerometer is calibrated, the accelerometer can be used to collect the acceleration of the drone. Specifically, the accelerometer collects the acceleration to be calibrated corresponding to the drone, filters the acceleration to be calibrated, and updates the filtered acceleration to be calibrated through the target error model to obtain the calibrated acceleration corresponding to the drone. In specific implementation, the filtered acceleration to be calibrated is input into the above-mentioned target error model to obtain the corresponding calibrated acceleration. The embodiment of the present invention can significantly improve the accuracy of the acceleration output by the accelerometer, such as Figure 2 A schematic diagram of calibration effect comparison is shown, and Figure 3 A schematic diagram showing the comparison of calibration effects at a horizontal angle is shown.

[0057] To facilitate understanding of the calibration method for an accelerometer in a drone provided in the aforementioned embodiment, an embodiment of the present invention provides an application example of the calibration method for an accelerometer in a drone, as shown in (1) to (7) below:

[0058] (1) Establish a horizontal reference surface as a test bench.

[0059] () 2. Calculate the accurate four tilt angles β1, β2, β3 and β4 according to the design drawings of the UAV.

[0060] (3) Place the drone horizontally on the test bench and record the average value of the drone when it is stationary on the first reference surface for 5 seconds.

[0061] (4) Place the drone on the test bench at an angle and record the average value of the drone remaining stationary for 5 seconds on the four tilted reference surfaces.

[0062] (5) Determine the reference surface based on the polarity and magnitude of each coordinate axis of the acceleration measurement value, and calculate the rotation matrix based on the relationship between the tilt angle and the reference Euler angle Further obtain the reference acceleration a ref .

[0063] (6) Calculate calibration parameters based on parameter solution equations To obtain the parameters M and B.

[0064] (7) Update acceleration data. The calibrated data can be used for inertial navigation fusion.

[0065] In summary, the accelerometer calibration method for drones provided by the embodiments of the present invention not only ensures calibration accuracy, but also adapts to different aircraft models and eliminates the need for complex manual operations. It is suitable for small multi-rotor drones and improves the measurement accuracy of navigation systems. Furthermore, because the reference acceleration is calculated based on the tilt angle and no human intervention is required during the stationary reference surface, the calibration accuracy is significantly superior to manual six-plane calibration methods, and the operation process is simpler and faster.

[0066] Regarding the calibration method of the accelerometer in the drone provided in the above embodiment, an embodiment of the present invention provides a calibration device for the accelerometer in the drone, wherein the drone is placed stationary at multiple tilt angles on a preset test bench, and the drone is provided with an accelerometer, see Figure 4 The schematic diagram of the structure of a calibration device for an accelerometer in a drone is shown. The device mainly includes the following parts:

[0067] The reference acceleration determination module 402 is used to determine the reference acceleration corresponding to the UAV according to each tilt angle;

[0068] The measured acceleration acquisition module 404 is configured to acquire at least one measured acceleration corresponding to the drone through an accelerometer when the drone is stationary at an inclined angle;

[0069] The calibration module 406 is configured to calibrate the accelerometer according to the reference acceleration and the measured acceleration.

[0070] The accelerometer calibration device for a drone provided in an embodiment of the present invention calculates a corresponding reference acceleration based on the drone's tilt angle, and collects measured acceleration through the accelerometer when the drone is stationary at an tilt angle, thereby calibrating the accelerometer based on the reference acceleration and the measured acceleration. This embodiment of the present invention can not only reduce the impact of human factors on the accelerometer calibration process, but also significantly improve the calibration accuracy of the accelerometer.

[0071] In one embodiment, the calibration module 406 is further used to: identify the tilt angle corresponding to each measured acceleration based on the extreme value of each measured acceleration; determine the mean acceleration corresponding to each tilt angle based on the measured acceleration corresponding to each tilt angle; determine the target error model corresponding to the accelerometer based on the reference acceleration and the mean acceleration corresponding to each tilt angle, so as to calibrate the accelerometer based on the accelerometer error model.

[0072] In one embodiment, the calibration module 406 is further used to: obtain an initial error model corresponding to the accelerometer; use the least squares method to fit the parameter solution equation corresponding to the initial error model, and use the Gauss-Jordan elimination method to invert the high-dimensional matrix in the parameter solution equation to obtain target model parameters; update the initial error model based on the target model parameters to obtain the target error model corresponding to the accelerometer.

[0073] In one embodiment, the above-mentioned device also includes an acceleration addition module, which is used to: collect the acceleration to be calibrated corresponding to the drone through an accelerometer; filter the acceleration to be calibrated, and update the filtered acceleration to be calibrated through a target error model to obtain the calibrated acceleration corresponding to the drone.

[0074] In one embodiment, the tilt angle includes a horizontal angle, a first tilt angle, and a second tilt angle, and the plane where the horizontal angle is located, the plane where the first tilt angle is located, and the plane where the second tilt angle is located are perpendicular to each other.

[0075] In one embodiment, the drone is provided with a drone support part, a drone left arm, a drone right arm, a drone head and a drone tail, the first tilt angle includes a left tilt angle and / or a right tilt angle, and the second tilt angle includes a front tilt angle and / or a rear tilt angle; the above-mentioned device also includes a tilt angle determination module, which is used to: determine the left tilt angle according to the relative position relationship between the drone support part and the drone left arm; and, determine the right tilt angle according to the relative position relationship between the drone support part and the drone right arm; and, determine the front tilt angle according to the relative position relationship between the drone support part and the drone head; and, determine the rear tilt angle according to the relative position relationship between the drone support part and the drone tail.

[0076] In one embodiment, the reference acceleration determination module 402 is further used to: obtain the horizontal gravity acceleration corresponding to the horizontal angle; determine the left gravity acceleration corresponding to the left tilt angle, the right gravity acceleration corresponding to the right tilt angle, the front gravity acceleration corresponding to the front tilt angle, and the rear gravity acceleration corresponding to the rear tilt angle based on the horizontal gravity acceleration and a preset coordinate system conversion matrix; and obtain the reference acceleration corresponding to the drone according to the horizontal neutral acceleration, the left gravity acceleration, the right gravity acceleration, the front gravity acceleration, and the rear gravity acceleration.

[0077] The device provided in the embodiment of the present invention has the same implementation principle and technical effects as those in the aforementioned method embodiment. For the sake of brief description, for matters not mentioned in the device embodiment, reference can be made to the corresponding content in the aforementioned method embodiment.

[0078] An embodiment of the present invention provides an electronic device. Specifically, the electronic device includes a processor and a storage device. The storage device stores a computer program, and when the computer program is executed by the processor, it executes the method described in any one of the above-mentioned embodiments.

[0079] Figure 5 This is a structural diagram of an electronic device provided in an embodiment of the present invention. The electronic device 100 includes: a processor 50, a memory 51, a bus 52 and a communication interface 53. The processor 50, the communication interface 53 and the memory 51 are connected via the bus 52; the processor 50 is used to execute an executable module stored in the memory 51, such as a computer program.

[0080] The memory 51 may include high-speed random access memory (RAM) and may also include non-volatile memory, such as at least one disk storage. The system network element communicates with at least one other network element via at least one communication interface 53 (which may be wired or wireless), and may utilize the Internet, a wide area network, a local area network, a metropolitan area network, or the like.

[0081] The bus 52 may be an ISA bus, a PCI bus, or an EISA bus. The bus may be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, Figure 5 Only one bidirectional arrow is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0082] Among them, the memory 51 is used to store programs, and the processor 50 executes the program after receiving the execution instruction. The method executed by the device for flow process definition disclosed in any embodiment of the above-mentioned embodiment of the present invention can be applied to the processor 50 or implemented by the processor 50.

[0083] The processor 50 may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method may be completed by hardware integrated logic circuits or software instructions in the processor 50. The processor 50 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be 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, or discrete hardware components. It may implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in conjunction with the embodiments of the present invention may be directly implemented and executed by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software module may be located in a storage medium well-known in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or the like. The storage medium is located in the memory 51 , and the processor 50 reads the information in the memory 51 and completes the steps of the above method in combination with its hardware.

[0084] The computer program product of the readable storage medium provided in the embodiment of the present invention includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the method described in the previous method embodiment. The specific implementation can be referred to the previous method embodiment and will not be repeated here.

[0085] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0086] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed by the present invention, or replace some of the technical features therein with equivalents. Such modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A method for calibrating an accelerometer in a drone, characterized in that: The drone is placed stationary on a preset test bench at multiple tilt angles, the tilt angles including a horizontal angle, a first tilt angle, and a second tilt angle, and the planes containing the horizontal angle, the first tilt angle, and the second tilt angle are perpendicular to each other. The drone is provided with an accelerometer, including: Determining a reference acceleration corresponding to the drone according to each of the tilt angles; When the drone is stationary at the tilt angle, collecting at least one measured acceleration corresponding to the drone by the accelerometer; Calibrating the accelerometer according to the reference acceleration and the measured acceleration includes: identifying the tilt angle corresponding to each measured acceleration according to the extreme value of each measured acceleration; determining the mean acceleration corresponding to each tilt angle according to the measured acceleration corresponding to each tilt angle; determining a target error model corresponding to the accelerometer based on the reference acceleration and the mean acceleration corresponding to each tilt angle, so as to calibrate the accelerometer based on the accelerometer error model; The drone is provided with a drone support part, a drone left arm, a drone right arm, a drone head and a drone tail, the first tilt angle includes a left tilt angle and / or a right tilt angle, and the second tilt angle includes a front tilt angle and / or a rear tilt angle; when the drone support part and the drone left arm are used as fulcrums, the drone is stationary at the left tilt angle; when the drone support part and the drone right arm are used as fulcrums, the drone is stationary at the right tilt angle; when the drone support part and the drone head are used as fulcrums, the drone is stationary at the front tilt angle; when the drone support part and the drone tail are used as fulcrums, the drone is stationary at the rear tilt angle; Before the step of determining the reference acceleration corresponding to the drone according to each of the tilt angles, the method further includes: determining the left tilt angle according to the relative position relationship between the drone support part and the left arm of the drone; determining the right tilt angle according to the relative position relationship between the drone support part and the right arm of the drone; determining the front tilt angle according to the relative position relationship between the drone support part and the head of the drone; and determining the rear tilt angle according to the relative position relationship between the drone support part and the tail of the drone.

2. The method according to claim 1, characterized in that The step of determining a target error model corresponding to the accelerometer based on the reference acceleration and the mean acceleration corresponding to each of the tilt angles includes: Obtaining an initial error model corresponding to the accelerometer; The parameter solution equation corresponding to the initial error model is fitted using the least squares method, and the high-dimensional matrix in the parameter solution equation is inverted using the Gauss-Jordan elimination method to obtain the target model parameters; The initial error model is updated based on the target model parameters to obtain a target error model corresponding to the accelerometer.

3. The method according to claim 1, characterized in that After the step of calibrating the accelerometer according to the reference acceleration and the measured acceleration, the method further comprises: Collecting the acceleration to be calibrated corresponding to the drone through the accelerometer; The acceleration to be calibrated is filtered, and the filtered acceleration to be calibrated is updated using the target error model to obtain a calibrated acceleration corresponding to the UAV.

4. The method according to claim 1, wherein The step of determining a reference acceleration corresponding to the drone according to each tilt angle includes: Obtaining the horizontal gravitational acceleration corresponding to the horizontal angle; Based on the horizontal gravitational acceleration and a preset coordinate system conversion matrix, respectively determining a left gravitational acceleration corresponding to the left tilt angle, a right gravitational acceleration corresponding to the right tilt angle, a front gravitational acceleration corresponding to the front tilt angle, and a rear gravitational acceleration corresponding to the rear tilt angle; A reference acceleration corresponding to the UAV is obtained according to the horizontal gravity acceleration, the left gravity acceleration, the right gravity acceleration, the front gravity acceleration, and the rear gravity acceleration.

5. A calibration device for an accelerometer in a drone, characterized in that: The drone is placed stationary on a preset test bench at multiple tilt angles, the tilt angles including a horizontal angle, a first tilt angle, and a second tilt angle, and the planes containing the horizontal angle, the first tilt angle, and the second tilt angle are perpendicular to each other. The drone is provided with an accelerometer, including: A reference acceleration determination module, configured to determine a reference acceleration corresponding to the drone according to each tilt angle; a measured acceleration acquisition module, configured to acquire, by means of the accelerometer, at least one measured acceleration corresponding to the drone when the drone is stationary at the tilt angle; a calibration module, configured to calibrate the accelerometer based on the reference acceleration and the measured acceleration, comprising: identifying the tilt angle corresponding to each measured acceleration based on an extreme value of each measured acceleration; determining a mean acceleration corresponding to each tilt angle based on the measured acceleration corresponding to each tilt angle; and determining a target error model corresponding to the accelerometer based on the reference acceleration and the mean acceleration corresponding to each tilt angle, so as to calibrate the accelerometer based on the accelerometer error model; The drone is provided with a drone support part, a drone left arm, a drone right arm, a drone head and a drone tail, the first tilt angle includes a left tilt angle and / or a right tilt angle, and the second tilt angle includes a front tilt angle and / or a rear tilt angle; when the drone support part and the drone left arm are used as fulcrums, the drone is stationary at the left tilt angle; when the drone support part and the drone right arm are used as fulcrums, the drone is stationary at the right tilt angle; when the drone support part and the drone head are used as fulcrums, the drone is stationary at the front tilt angle; when the drone support part and the drone tail are used as fulcrums, the drone is stationary at the rear tilt angle; It also includes a tilt angle determination module, which is used to: determine the left tilt angle according to the relative position relationship between the drone support part and the left arm of the drone; determine the right tilt angle according to the relative position relationship between the drone support part and the right arm of the drone; determine the front tilt angle according to the relative position relationship between the drone support part and the head of the drone; and determine the rear tilt angle according to the relative position relationship between the drone support part and the tail of the drone.

6. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the memory stores computer-executable instructions that can be executed by the processor, and the processor executes the computer-executable instructions to implement the method according to any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions. When the computer-executable instructions are called and executed by a processor, the computer-executable instructions prompt the processor to implement the method according to any one of claims 1 to 4.

Images