A method, device, medium and equipment for measuring the altitude during the landing stage of a drone

Abstract

The present invention provides a method, device, medium and equipment for measuring the height of an unmanned aerial vehicle (UAV) during the landing phase. When the current phase is the initial descent phase, the current barometric height is used as the height fusion index; when the current phase is the near-ground descent phase, the current barometric height and the current visual height are used as the height fusion index; when the current phase is the landing phase, the current visual height is used as the height fusion index; and the height fusion index and the height change amount are processed by fusion to obtain the current fusion height of the UAV relative to the landing field, where the height change amount is the height difference of the UAV at the current moment relative to the previous moment obtained based on inertial measurement. Considering the instability of the barometer at low altitudes and the measurement range limitation of visual recognition, the accuracy of the height fusion index is optimized in stages to improve the accuracy of the calculation result of the current fusion height, so as to ensure the safe landing of the UAV.

Description

Technical Field

[0001] The present invention relates to the field of unmanned aerial vehicles, and more particularly, to a method, device, medium, and equipment for measuring the height of an unmanned aerial vehicle during the landing phase. Background Art

[0002] With the development of urban low-altitude transportation, unmanned aerial vehicles are increasingly widely used in fields such as logistics distribution, urban inspection, and emergency rescue due to their flexible and highly maneuverable characteristics. The control process of an unmanned aerial vehicle includes a takeoff phase, a flight phase, and a landing phase. Among them, the landing phase is one of the most complex and critical phases during the flight of an unmanned aerial vehicle.

[0003] During the landing process of an unmanned aerial vehicle, corresponding parameters need to be adjusted according to its height change to achieve the purpose of safe landing. The accuracy requirement for height measurement during the landing phase of an unmanned aerial vehicle is extremely high. How to accurately and quickly obtain the height of an unmanned aerial vehicle during the landing phase has become a difficult problem that has been continuously concerned by those skilled in the art. Summary of the Invention

[0004] The purpose of the present invention is to provide a method, device, medium, and equipment for measuring the height of an unmanned aerial vehicle during the landing phase to improve the above problems.

[0005] To achieve the above purpose, the technical solutions adopted in the embodiments of the present invention are as follows:

[0006] In a first aspect, an embodiment of the present invention provides a method for measuring the height of an unmanned aerial vehicle during the landing phase, the method including:

[0007] When the current phase is the initial descent phase, taking the current barometric height as the height fusion index;

[0008] When the current phase is the near-ground descent phase, taking the current barometric height and the current visual height as the height fusion index;

[0009] When the current phase is the landing phase, taking the current visual height as the height fusion index;

[0010] Performing fusion processing according to the height fusion index and the height change amount to obtain the current fusion height of the unmanned aerial vehicle relative to the landing field, where the height change amount is the height difference of the unmanned aerial vehicle at the current moment relative to the previous moment obtained based on inertial measurement.

[0011] In a second aspect, an embodiment of the present invention provides a device for measuring the height of an unmanned aerial vehicle during the landing phase, the device including:

[0012] The first processing unit is configured to use the current barometric altitude as the altitude fusion index when the current stage is the initial descent stage; use the current barometric altitude and the current visual altitude as the altitude fusion index when the current stage is the near-ground descent stage; and use the current visual altitude as the altitude fusion index when the current stage is the landing stage.

[0013] The second processing unit is configured to perform fusion processing based on the altitude fusion index and the altitude change amount to obtain the current fusion altitude of the UAV relative to the landing site, where the altitude change amount is the altitude difference of the UAV at the current moment relative to the previous moment based on inertial measurement.

[0014] In a third aspect, an embodiment of the present invention provides a storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the above method is implemented.

[0015] In a fourth aspect, an embodiment of the present invention provides an electronic device, the electronic device includes: a processor and a memory, the memory is used to store one or more programs; when the one or more programs are executed by the processor, the above method is implemented.

[0016] Compared with the prior art, a method, device, medium and equipment for measuring the altitude of a UAV during the landing stage provided by the embodiments of the present invention use the current barometric altitude as the altitude fusion index when the current stage is the initial descent stage; use the current barometric altitude and the current visual altitude as the altitude fusion index when the current stage is the near-ground descent stage; use the current visual altitude as the altitude fusion index when the current stage is the landing stage; and perform fusion processing based on the altitude fusion index and the altitude change amount to obtain the current fusion altitude of the UAV relative to the landing site, where the altitude change amount is the altitude difference of the UAV at the current moment relative to the previous moment based on inertial measurement. Considering the instability of the barometer at low altitudes and the measurement range limitation of visual recognition, the accuracy of the altitude fusion index is optimized in stages to improve the accuracy of the current fusion altitude calculation result to ensure the safe landing of the UAV.

[0017] To make the above objects, features and advantages of the present invention more obvious and understandable, the following specific preferred embodiments are given and described in detail in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 Schematic diagram of the structure of the electronic device provided by the embodiment of the present invention.

[0020] Figure 2 One of the schematic flowcharts of the method for measuring the height of the drone during the landing phase provided by the embodiment of the present invention.

[0021] Figure 3 Schematic diagram of the federated Kalman filter height fusion process provided by the embodiment of the present invention.

[0022] Figure 4 Another schematic flowchart of the method for measuring the height of the drone during the landing phase provided by the embodiment of the present invention.

[0023] Figure 5 Another schematic flowchart of the method for measuring the height of the drone during the landing phase provided by the embodiment of the present invention.

[0024] Figure 6 Another schematic flowchart of the method for measuring the height of the drone during the landing phase provided by the embodiment of the present invention.

[0025] Figure 7 Schematic diagram of the units of the device for measuring the height of the drone during the landing phase provided by the embodiment of the present invention.

[0026] In the figure: 10 - processor; 11 - memory; 12 - bus; 13 - communication interface; 601 - first processing unit; 602 - second processing unit. Detailed implementation manners

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0029] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0030] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

[0031] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is customarily placed during use. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0032] In the description of the present invention, it should also be noted that, unless otherwise clearly specified and defined, the terms "arranged" and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] The following will, with reference to the drawings, give a detailed description of some embodiments of the present invention. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0034] Embodiments of the present invention provide an electronic device, which may be a central control unit of a drone, a low-altitude flight management server, or a user terminal device, such as a mobile phone, a computer, etc. Please refer to Figure 1 , the structural schematic diagram of the electronic device. The electronic device includes a processor 10, a memory 11, and a bus 12. The processor 10 and the memory 11 are connected through the bus 12, and the processor 10 is used to execute an executable module stored in the memory 11, such as a computer program.

[0035] The processor 10 can be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the method for measuring the height of the drone during the landing phase can be completed by the hardware integrated logic circuit in the processor 10 or the instructions in the form of software. The above-mentioned processor 10 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can 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 gates or transistor logic devices, discrete hardware components.

[0036] The memory 11 may include a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk memory.

[0037] The bus 12 may be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus. Figure 1 Although only one bidirectional arrow is used in the figure, it does not mean that there is only one bus 12 or only one type of bus 12 .

[0038] The memory 11 is used to store programs, such as programs corresponding to the device for measuring the height of the drone during the landing phase. The device for measuring the height of the drone during the landing phase includes at least one software function module that can be stored in the memory 11 in the form of software or firmware or fixed in the operating system (OS) of the electronic device. After receiving the execution instruction, the processor 10 executes the program to implement the method for measuring the height of the drone during the landing phase.

[0039] Possibly, the electronic device provided by the embodiment of the present invention further includes a communication interface 13. The communication interface 13 is connected to the processor 10 via a bus.

[0040] It should be understood that Figure 1The structure shown is only a schematic diagram of a part of the electronic device. The electronic device may further include more or fewer components than those shown in Figure 1 or have a different configuration from that shown in Figure 1 . Figure 1 Each component shown in can be implemented by hardware, software, or a combination thereof.

[0041] A method for measuring the height of a drone during the landing phase provided by an embodiment of the present invention can be applied, but is not limited to, to the Figure 1 electronic device shown. For the specific process, please refer to Figure 2 . The height measurement during the landing phase of the drone includes: S41, S42, S43, and S50, which are specifically described as follows.

[0042] S41. When the current phase is the initial descent phase, the current barometric height is used as the height fusion index.

[0043] It should be noted that during the initial descent phase, the height of the drone is greater than the first threshold. At this time, it exceeds the effective measurement range of the visual recognition height measurement method. Therefore, the current barometric height is used as the height fusion index.

[0044] S42. When the current phase is the near - ground descent phase, the current barometric height and the current visual height are used as the height fusion index.

[0045] It should be noted that during the near - ground descent phase, the height of the drone is less than or equal to the first threshold and greater than the second threshold. By using the current barometric height and the current visual height as the height fusion index and performing fusion processing, the accuracy of the final result is ensured.

[0046] S43. When the current phase is the landing phase, the current visual height is used as the height fusion index.

[0047] It should be noted that during the landing phase, the height of the drone is less than or equal to the second threshold. At this time, the barometric altimeter is prone to being affected by environmental factors (such as temperature, air pressure) in the near - ground low - height range. Therefore, the current visual height is used as the height fusion index.

[0048] Among them, the initial descent phase is higher than the near - ground descent phase, and the near - ground descent phase is higher than the landing phase. The current barometric height is the height between the drone and the landing site measured by the barometric height measurement method at the current moment, and the current visual height is the height between the drone and the landing site measured by the visual recognition height measurement method at the current moment.

[0049] S50. Perform fusion processing based on the height fusion index and the height change amount to obtain the current fusion height of the drone relative to the landing site.

[0050] Among them, the height change amount is the height difference of the drone at the current moment relative to the previous moment obtained based on inertial measurement. The fusion processing method can be fusion through the Federated Kalman Filter algorithm, and the current fused height can be used as a control parameter for the drone landing stage.

[0051] In the method for measuring the height of the drone during the landing stage provided by the embodiments of the present invention, considering the instability of the barometer at low altitudes and the measurement range limitation of visual recognition, the accuracy of the height fusion index is optimized in stages to improve the accuracy of the calculation result of the current fused height, so as to ensure the safe landing of the drone.

[0052] Optionally, the formula for the height change amount is:

[0053]

[0054] Among them, represents the height change amount, represents the acceleration of the drone in the vertical direction, which can be measured by an inertial measurement unit deployed on the drone. t is the current moment, t - 1 is the previous moment, and t in the formula is greater than or equal to 1. When t is 1, t - 1 = 0, representing the initial moment.

[0055] The embodiments of the present invention also provide a filter bank, which includes a first Kalman filter, a second Kalman filter, and a main filter. Among them, the first Kalman filter, the second Kalman filter, and the main filter constitute a Federated Kalman Filter. The filter bank can adopt the Federated Kalman Filter algorithm to fuse the current barometric height, the current visual height, and the height change amount, eliminate their respective measurement errors, and obtain more accurate height data, that is, obtain the current fused height of the drone relative to the reference plane.

[0056] On this basis, regarding the content in S50, the present invention also provides an optional implementation manner. Please refer to the following text.

[0057] When the drone is in the initial descent stage, step S50 of performing fusion processing according to the height fusion index and the height change amount to obtain the current fused height of the drone relative to the landing field includes: S511, S512, and S513, which are specifically described as follows.

[0058] S511, input the current barometric height and the height change amount into the first Kalman filter.

[0059] S512, The first Kalman filter generates the current barometric altitude estimate and the current barometric altitude covariance estimate based on the current barometric altitude, the altitude change, the fused altitude at the previous moment, and the fused covariance at the previous moment.

[0060] S513, The main filter determines the current fused altitude and the current fused covariance at the current moment based on the current barometric altitude estimate, the current barometric altitude covariance estimate, and the altitude change.

[0061] When the UAV is in the near-ground descent stage, step S50 of performing fusion processing based on the altitude fusion index and the altitude change to obtain the current fused altitude of the UAV relative to the landing site includes: S521, S522, S523, S524, and S525, which are specifically described as follows.

[0062] S521, Input the current barometric altitude and the altitude change into the first Kalman filter.

[0063] S522, Input the current visual altitude and the altitude change into the second Kalman filter.

[0064] S523, The first Kalman filter generates the current barometric altitude estimate and the current barometric altitude covariance estimate based on the current barometric altitude, the altitude change, the fused altitude at the previous moment, and the fused covariance at the previous moment.

[0065] S524, The second Kalman filter generates the current visual altitude estimate and the current visual altitude covariance estimate based on the current visual altitude, the altitude change, the fused altitude at the previous moment, and the fused covariance at the previous moment.

[0066] S525, The main filter determines the current fused altitude and the current fused covariance at the current moment based on the current barometric altitude estimate, the current barometric altitude covariance estimate, the current visual altitude estimate, the current visual altitude covariance estimate, and the altitude change.

[0067] When the UAV is in the landing stage, step S50 of performing fusion processing based on the altitude fusion index and the altitude change to obtain the current fused altitude of the UAV relative to the landing site includes: S531, S532, and S533, which are specifically described as follows.

[0068] S531, Input the current visual altitude and the altitude change into the second Kalman filter.

[0069] S532, The second Kalman filter generates the current visual altitude estimate and the current visual altitude covariance estimate based on the current visual altitude, the altitude change, the fused altitude at the previous moment, and the fused covariance at the previous moment.

[0070] S533, the main filter determines the current fusion altitude and the current fusion covariance at the current moment based on the current visual altitude estimate, the current visual altitude covariance estimate, and the altitude change amount.

[0071] Please refer to Figure 3 , Figure 3 which is a schematic diagram of the federated Kalman filter altitude fusion process provided by an embodiment of the present invention. The first Kalman filter is a barometric altitude Kalman filter, and the second Kalman filter is a visual altitude Kalman filter. represents the current barometric altitude, represents the altitude change amount, represents the current visual altitude, represents the current barometric altitude estimate, represents the current barometric high and low pressure covariance estimate, represents the current visual altitude estimate, represents the current visual altitude covariance estimate, represents the current fusion altitude, represents the current fusion covariance.

[0072] As Figure 3 shown, the altitude change amount derived from the measurement data of the inertial measurement unit, the current barometric altitude derived from the measurement data of the barometer, and the current visual altitude derived from the measurement data of the visual recognition model. By controlling the first switch disposed at the rear end of the barometer and the second switch disposed at the rear end of the visual recognition model, the corresponding altitude fusion index and altitude change amount can be input into the filter bank in the initial descent stage, the near-ground descent stage, and the landing stage.

[0073] In the initial descent stage and the near-ground descent stage, the first switch is in the closed state, and in the near-ground descent stage and the landing stage, the second switch is in the closed state.

[0074] Taking the near-ground descent stage as an example, the current barometric altitude and the altitude change amount are input into the first Kalman filter. The current visual altitude and the altitude change amount are input into the second Kalman filter. The main filter will feedback the obtained current fusion altitude and the current fusion covariance to the first Kalman filter and the second Kalman filter. Therefore, the first Kalman filter and the second Kalman filter can obtain the fusion altitude at the previous moment and the fusion covariance at the previous moment.

[0075] Furthermore, the first Kalman filter generates the current barometric altitude estimate and the current barometric altitude covariance estimate based on the current barometric altitude, the altitude change, the fused altitude at the previous moment, and the fused covariance at the previous moment. The second Kalman filter generates the current visual altitude estimate and the current visual altitude covariance estimate based on the current visual altitude, the altitude change, the fused altitude at the previous moment, and the fused covariance at the previous moment.

[0076] The first Kalman filter can send the current barometric altitude estimate and the current barometric altitude covariance estimate to the main filter, and the second Kalman filter can send the current visual altitude estimate and the current visual altitude covariance estimate to the main filter. The main filter determines the current fused altitude and the current fused covariance at the current moment based on the current barometric altitude estimate, the current barometric altitude covariance estimate, the current visual altitude estimate, the current visual altitude covariance estimate, and the altitude change.

[0077] It should be understood that through the fusion of the federated Kalman filter algorithm and the altitude data of the inertial measurement unit, the measurement errors of each are eliminated, and more accurate altitude data is obtained.

[0078] It should be noted that at the moment when the drone enters the landing stage, the covariance and the altitude estimate based on the flight path are calculated.

[0079] On the basis of the foregoing, with regard to how to obtain the current barometric altitude between the drone and the landing site, the embodiment of the present invention also provides an optional implementation manner. Please refer to Figure 4 . When the drone is in the initial descent stage and the near-ground descent stage, the drone landing stage altitude measurement method further includes: S11 and S12, which are specifically described as follows.

[0080] S11, obtain the current landing site temperature, the current landing site pressure, and the current drone pressure.

[0081] It should be understood that a barometer can be set on the drone to obtain the current drone pressure. A barometer and a temperature measurement device can be set at the landing site to obtain the current landing site pressure and the current landing site temperature.

[0082] S12, obtain the current barometric altitude between the drone and the landing site according to the current landing site temperature, the current landing site pressure, and the current drone pressure.

[0083] Optionally, the formula for the current barometric altitude between the drone and the landing site is as follows:

[0084]

[0085] Among them, represents the current barometric altitude (unit: meter), represents the current temperature of the landing site (unit: Kelvin, K), represents the current barometric pressure of the UAV (unit: Pascal, Pa), represents the current barometric pressure of the landing site (unit: Pascal, Pa), L represents the lapse rate of air temperature with height (which can be 0.0065 K / m), R represents the gas constant, the value of which can be 287.05 J / (kg·K), g is the standard acceleration of gravity, approximately 9.80665 m / s², and M is the average molar mass of air, approximately 0.028964 kg / mol.

[0086] On the basis of the foregoing, with regard to how to obtain the current visual altitude of the UAV, the embodiment of the present invention further provides an optional implementation manner. Please refer to Figure 5 . When the UAV is in the near-ground descent stage, the UAV landing stage altitude measurement method further includes: S21 and S22, which are specifically described as follows.

[0087] S21, collect the first type of image corresponding to the first type of target deployed at the landing site.

[0088] Among them, the first type of target is a large target. The large target is usually a set of fixed images with obvious features compared with other things in the landing site environment. The images need to have fixed contour dimensions and features for distinguishing the orientation, and are mainly used to assist in positioning in the initial landing section. The large target is at the same height as the landing site.

[0089] S22, input the first type of image and the current attitude of the UAV into the visual recognition model to obtain the current visual altitude.

[0090] It should be noted that the visual recognition model can be a machine learning model trained with label data to a converged state, also called a target recognition model, and is deployed in the upper electronic device. Among them, the recognition success rate in different scenarios is greater than δ.

[0091] When the altitude of the UAV is less than or equal to the first threshold (the effective recognition upper limit of the first type of target), that is, when the large target image can be clearly observed, visual recognition is enabled, and the first type of image and the current attitude of the UAV are input into the visual recognition model to obtain the current visual altitude.

[0092] On the basis of the foregoing, with regard to how to obtain the current visual altitude of the UAV, the embodiment of the present invention further provides an optional implementation manner. Please refer to Figure 6 . When the UAV is in the landing stage, the UAV landing stage altitude measurement method further includes: S31 and S32, which are specifically described as follows.

[0093] S31, collect the second type of images corresponding to the second type of targets deployed at the landing site.

[0094] Among them, the planar area of the second type of target is smaller than that of the first type of target. The second type of target is a small target, and the small target is an accessory recognition feature on the large target, mainly used as a supplementary positioning means when the large target image cannot be fully captured within the camera's field of view when the flight altitude is lower than a certain level, assisting the aircraft in positioning near the ground and finally landing. The small target needs to have a fixed contour size and features for distinguishing the orientation.

[0095] S32, input the second type of images and the current attitude of the UAV into the visual recognition model to obtain the current visual altitude.

[0096] When the altitude of the UAV is less than or equal to the second threshold (the effective recognition upper limit of the second type of target), that is, when the small target image can be clearly observed, input the second type of images and the current attitude of the UAV into the visual recognition model to obtain the current visual altitude and ensure its accuracy.

[0097] In an alternative embodiment, after obtaining the current fusion altitude of the UAV relative to the landing site, it can also be converted according to the conversion coefficient to obtain the current altitude of the UAV relative to the altitude reference plane. The conversion coefficient represents the height difference between the landing site and the altitude reference plane.

[0098] Please refer to Figure 7 , Figure 7 a height measurement device for a UAV during the landing phase provided by an embodiment of the present invention. Optionally, the height measurement device for a UAV during the landing phase is applied to the electronic device described above.

[0099] The height measurement device for a UAV during the landing phase includes: a first processing unit 601 and a second processing unit 602.

[0100] The first processing unit 601 is configured to use the current barometric altitude as the altitude fusion index when the current phase is the initial descent phase; use the current barometric altitude and the current visual altitude as the altitude fusion index when the current phase is the near-ground descent phase; use the current visual altitude as the altitude fusion index when the current phase is the landing phase;

[0101] The second processing unit 602 is configured to perform a fusion process based on the altitude fusion index and the altitude change amount to obtain the current fusion altitude of the UAV relative to the landing site, where the altitude change amount is the altitude difference of the UAV at the current moment relative to the previous moment based on inertial measurement.

[0102] Optionally, the second processing unit 602 may execute S50 described above, and the first processing unit 601 may execute the other steps described above.

[0103] It should be noted that the height measurement device for the drone landing stage provided in this embodiment can execute the method flow shown in the above method flow embodiment to achieve the corresponding technical effects. For the sake of brief description, for the parts not mentioned in this embodiment, reference can be made to the corresponding content in the above embodiment.

[0104] The embodiment of the present invention also provides a storage medium, which stores computer instructions and programs. When the computer instructions and programs are read and run, they execute the method for measuring the height of the drone landing stage in the above embodiment. The storage medium may include memory, flash memory, registers or a combination thereof, etc.

[0105] The following provides an electronic device, which can be the central control unit of a drone, can be a low-altitude flight management server, or can also be a user terminal device, such as a mobile phone, a computer, etc. The electronic device as Figure 1 shown can implement the above method for measuring the height of the drone landing stage; specifically, the electronic device includes: a processor 10, a memory 11, and a bus 12. The processor 10 may be a CPU. The memory 11 is used to store one or more programs. When the one or more programs are executed by the processor 10, the method for measuring the height of the drone landing stage in the above embodiment is executed.

[0106] In summary, for the method, device, medium and equipment for measuring the height of the drone landing stage provided by the embodiment of the present invention, when the current stage is the initial descent stage, the current barometric height is used as the height fusion index; when the current stage is the near-ground descent stage, the current barometric height and the current visual height are used as the height fusion index; when the current stage is the landing stage, the current visual height is used as the height fusion index; and the height fusion index and the height change amount are fused to obtain the current fusion height of the drone relative to the landing field, where the height change amount is the height difference of the drone at the current moment relative to the previous moment obtained based on inertial measurement. Considering the instability of the barometer at low altitudes and the measurement range limitation of visual recognition, the accuracy of the height fusion index is optimized in stages to improve the accuracy of the current fusion height calculation result to ensure the safe landing of the drone.

[0107] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0108] It is obvious to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, in any respect, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Thus, all changes that fall within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims concerned.

Claims

1. A method for measuring the altitude of an unmanned aerial vehicle during the landing phase, characterized in that, The method includes: When the current stage is the initial descent stage, using the current barometric altitude as the altitude fusion index; When the current stage is the near-ground descent stage, using the current barometric altitude and the current visual altitude as the altitude fusion index; When the current stage is the landing stage, using the current visual altitude as the altitude fusion index; Performing fusion processing based on the altitude fusion index and the altitude change amount to obtain the current fusion altitude of the UAV relative to the landing field, where the altitude change amount is the altitude difference of the UAV at the current moment relative to the previous moment based on inertial measurement; When the UAV is in the landing stage, the step of performing fusion processing based on the altitude fusion index and the altitude change amount to obtain the current fusion altitude of the UAV relative to the landing field includes: inputting the current visual altitude and the altitude change amount into a second Kalman filter; the second Kalman filter generates a current visual altitude estimated value and a current visual altitude covariance estimated value according to the current visual altitude, the altitude change amount, the fusion altitude at the previous moment, and the fusion covariance at the previous moment; the main filter determines the current fusion altitude and the current fusion covariance at the current moment according to the current visual altitude estimated value, the current visual altitude covariance estimated value, and the altitude change amount.

2. The method for measuring the altitude during the landing phase of the drone according to claim 1, wherein When the UAV is in the initial descent stage, the step of performing fusion processing based on the altitude fusion index and the altitude change amount to obtain the current fusion altitude of the UAV relative to the landing field includes: Inputting the current barometric altitude and the altitude change amount into a first Kalman filter; The first Kalman filter generates a current barometric altitude estimated value and a current barometric altitude covariance estimated value according to the current barometric altitude, the altitude change amount, the fusion altitude at the previous moment, and the fusion covariance at the previous moment; The main filter determines the current fusion altitude and the current fusion covariance at the current moment according to the current barometric altitude estimated value, the current barometric altitude covariance estimated value, and the altitude change amount.

3. The method for measuring the height during the landing stage of the unmanned aerial vehicle according to claim 1, wherein When the UAV is in the near-ground descent stage, the step of performing fusion processing based on the altitude fusion index and the altitude change amount to obtain the current fusion altitude of the UAV relative to the landing field includes: Inputting the current barometric altitude and the altitude change amount into a first Kalman filter; Inputting the current visual altitude and the altitude change amount into a second Kalman filter; The first Kalman filter generates a current barometric altitude estimated value and a current barometric altitude covariance estimated value according to the current barometric altitude, the altitude change amount, the fusion altitude at the previous moment, and the fusion covariance at the previous moment; The second Kalman filter generates a current visual altitude estimated value and a current visual altitude covariance estimated value according to the current visual altitude, the altitude change amount, the fusion altitude at the previous moment, and the fusion covariance at the previous moment; The main filter determines the current fusion altitude and the current fusion covariance at the current moment based on the current barometric altitude estimate, the current barometric altitude covariance estimate, the current visual altitude estimate, the current visual altitude covariance estimate, and the altitude change amount.

4. The method for measuring the altitude during the landing phase of the drone according to claim 1, wherein When the UAV is in the initial descent phase and the near-ground descent phase, the method further includes: Obtaining the current landing site temperature, the current landing site barometric pressure, and the current UAV barometric pressure; Obtaining the current barometric altitude between the UAV and the landing site based on the current landing site temperature, the current landing site barometric pressure, and the current UAV barometric pressure.

5. The method for measuring the altitude during the landing phase of the unmanned aerial vehicle according to claim 1, wherein, When the UAV is in the near-ground descent phase, the method further includes: Collecting first-class images corresponding to first-class targets deployed at the landing site; Inputting the first-class images and the current attitude of the UAV into a visual recognition model to obtain the current visual altitude.

6. The method for measuring the altitude during the landing phase of the drone according to claim 5, wherein, When the UAV is in the landing phase, the method further includes: Collecting second-class images corresponding to second-class targets deployed at the landing site, where the planar area of the second-class targets is smaller than the planar area of the first-class targets; Inputting the second-class images and the current attitude of the UAV into a visual recognition model to obtain the current visual altitude.

7. A height measurement device for an unmanned aerial vehicle during the landing phase, characterized in that, The device includes: A first processing unit, configured to use the current barometric altitude as the altitude fusion index when the current phase is the initial descent phase; use the current barometric altitude and the current visual altitude as the altitude fusion index when the current phase is the near-ground descent phase; and use the current visual altitude as the altitude fusion index when the current phase is the landing phase; A second processing unit, configured to perform a fusion process based on the altitude fusion index and the altitude change amount to obtain the current fusion altitude of the UAV relative to the landing site, where the altitude change amount is the altitude difference of the UAV at the current moment relative to the previous moment based on inertial measurement; When the UAV is in the landing phase, performing the fusion process based on the altitude fusion index and the altitude change amount to obtain the current fusion altitude of the UAV relative to the landing site includes: inputting the current visual altitude and the altitude change amount into a second Kalman filter; the second Kalman filter generates a current visual altitude estimate and a current visual altitude covariance estimate based on the current visual altitude, the altitude change amount, the fusion altitude at the previous moment, and the fusion covariance at the previous moment; the main filter determines the current fusion altitude and the current fusion covariance at the current moment based on the current visual altitude estimate, the current visual altitude covariance estimate, and the altitude change amount.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the method according to any one of claims 1-6.

9. An electronic device, characterized in that, Including: A processor and a memory, where the memory is used to store one or more programs; When the one or more programs are executed by the processor, the method according to any one of claims 1-6 is implemented.

Images