Air-drop parachute landing control method and device

Abstract

The invention relates to the technical field of air-drop parachute landing control, and provides an air-drop parachute landing control method and device. The method comprises the following steps: according to a starting point position and a target landing point of a material container, determining a target track capable of enabling the material container to land to the target landing point; determining a yaw distance and a track error angle of the material container relative to the target track according to the position of the material container; according to the yaw distance and the track error angle, the propelling speed of the material container is calculated, and the material container is propelled according to the propelling speed, so that the material container gets close to the target track and lands to the target landing point according to the target track. According to the method, the target track of the material container is calculated, the target track is taken as a reference, the material container is controlled, and the material container approaches the target track until the material container finally lands to the target landing point according to the target track, so that the influence of the external environment on the material container air-drop process can be eliminated, and the material container accurately reaches the target landing point.

Description

Technical Field

[0001] The present invention relates to the technical field of airdrop parachute control, and in particular to an airdrop parachute control method and device. Background Art

[0002] With the popularization of drone applications, drones have been widely used in all walks of life due to their low cost, wide flight range, and flexible use. In the field of transportation, especially in areas that are difficult to reach by traditional transportation methods, drones are playing a huge role. In the process of material delivery, drones generally use airdrop, direct drop or parachute to unload materials. The airdrop method is limited by the take-off and landing conditions of the target landing position, especially in the complex terrain environment in the field, it is difficult to achieve safe take-off and landing of drones; the direct drop method is limited by the drop height and the impact resistance of materials, and is not suitable for the delivery of fragile materials; the traditional parachute method can achieve the safe delivery of fragile materials, and there is no strict restriction on the drop height, but in the traditional parachute process, the parachute is opened immediately after the materials are thrown out. In the subsequent landing process, the landing trajectory is difficult to calculate and is particularly susceptible to environmental influences. Especially in a windy environment, the landing point of the materials often deviates from the predetermined position, which causes great inconvenience to the recovery of the delivered materials. In order to solve the problem of traditional parachute delivery of materials from drones, there is an urgent need for a control device and method that can accurately control the landing trajectory during the parachute drop process, so that the drone can finally land at the target point after dropping materials from the air.

[0003] In view of this, overcoming the defects of the prior art is an urgent problem to be solved in the field of this technology. Summary of the invention

[0004] The technical problem to be solved by the present invention is that in the existing airdrop parachute process, materials are easily affected by the environment after being thrown out, causing the landing point of the materials to deviate from the preset target landing point.

[0005] The present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides an airdrop parachute control method, comprising:

[0007] According to the starting point position and the target landing point of the cargo box, a target trajectory is determined that enables the cargo box to land at the target landing point;

[0008] Determine the deviation distance and track error angle of the cargo box relative to the target trajectory according to the position of the cargo box;

[0009] The propulsion speed of the cargo box is calculated according to the deviation distance and the track error angle, and the cargo box is propelled at the propulsion speed so as to approach the target trajectory and land at the target landing point according to the target trajectory.

[0010] Preferably, determining a target trajectory that enables the material cargo box to land at the target landing point according to the starting point position and the target landing point of the material cargo box specifically includes:

[0011] Calculate target track angle Calculate the first parameter

[0012] Determine the target trajectory as y=kx+b; wherein x0 is the horizontal coordinate of the starting point of the material cargo box, y0 is the vertical coordinate of the starting point of the material cargo box, x1 is the horizontal coordinate of the target landing point of the material cargo box, y1 is the vertical coordinate of the target landing point of the material cargo box, x is the horizontal coordinate of the corresponding point on the target trajectory, and y is the vertical coordinate of the corresponding point on the target trajectory.

[0013] Preferably, determining the deviation distance and track error angle of the material container relative to the target trajectory according to the position of the material container specifically includes:

[0014] Calculate the deviation Calculate the track error angle

[0015] Among them, x' is the horizontal coordinate of the current position of the material cargo box, y' is the vertical coordinate of the current position of the material cargo box, x1 is the horizontal coordinate of the target landing point of the material cargo box, y1 is the vertical coordinate of the target landing point of the material cargo box, k is the target track angle of the target trajectory, and b is the first parameter of the target trajectory.

[0016] Preferably, the calculation of the propulsion speed of the cargo box according to the deviation distance and the track error angle specifically includes:

[0017] Calculate the propulsion speed of the cargo box Δδ=ΔZ×(k p ×d1+k i ×d)+k d ×(d1-d0)+k0;

[0018] Wherein, ΔZ is the track error angle, d is the off-track distance, x0 is the horizontal coordinate of the starting point of the cargo box, y0 is the vertical coordinate of the starting point of the cargo box, x1 is the horizontal coordinate of the target landing point of the cargo box, y1 is the vertical coordinate of the target landing point of the cargo box, k is the target track angle of the target trajectory, b is the first parameter of the target trajectory, k p , k i , k d and k0 are preset coefficients.

[0019] In a second aspect, the present invention also provides an airdrop parachute control device, comprising a parachute 1, a parachute thrower 2, a positioner 3, a thruster 4 and a controller 5;

[0020] The parachute 1 is arranged above the cargo box 6 through the parachute thrower 2, and the propeller 4 is arranged on the side of the cargo box 6;

[0021] The locator 3 is used to detect the position of the material container 6;

[0022] The controller 5 sends a parachute throwing instruction to the parachute throwing device 2, and the parachute throwing device 2 is used to open the parachute 1 according to the parachute throwing instruction;

[0023] The controller 5 is also used to control the propulsion speed of the propeller 4 using the airdrop parachute control method described in the first aspect, so that the material cargo box 6 lands at the target landing point.

[0024] Preferably, the propeller 4 is a differential propeller, and the differential propeller includes a first propulsion unit 41 and a second propulsion unit 42;

[0025] The first propulsion unit 41 is disposed on a first side of the material cargo box 6, and the second propulsion unit 42 is disposed on a second side of the material cargo box 6, wherein the second side is a side opposite to the first side;

[0026] The controlling of the propulsion speed of the propeller 4 is specifically to control the fan speed difference of the differential propeller.

[0027] Preferably, the device further comprises a height sensor 7;

[0028] The height sensor 7 is used to detect the height of the material container 6;

[0029] The controller 5 is also used to send a parachute throwing instruction to the parachute throwing device 2 when the height of the material cargo box 6 reaches a preset height.

[0030] Preferably, the device further comprises a wireless communication module 8;

[0031] The wireless communication module 8 is used to receive wireless signals, obtain the target landing point of the material container 6 from the wireless signals, and transmit the target landing point to the controller 5 .

[0032] Preferably, the device further comprises one or more of a gyroscope 9, an accelerometer 10 and a geomagnetic sensor 11;

[0033] The gyroscope 9 is used to measure the angular velocity of the material container 6;

[0034] The accelerometer 10 is used to measure the linear acceleration of the material container 6;

[0035] The geomagnetic sensor 11 is used to measure the geomagnetic field at the location of the material container 6;

[0036] The controller 5 is also used to adjust the coefficients used in the control process of the thruster 4 according to one or more of the angular velocity, linear acceleration of the material container 6 and the geomagnetic field at the location of the material container 6.

[0037] Preferably, the device further comprises a power supply module 12, and the power supply module 12 is used to supply power to the parachute thrower 2, the positioner 3, the thruster 4 and the controller 5.

[0038] Compared with the prior art, the beneficial effect of the present invention lies in that: the present invention calculates the target trajectory of the material cargo box, uses the target trajectory as a reference, controls the material cargo box, and makes the material cargo box approach the target trajectory until it finally lands at the target landing point according to the target trajectory, thereby eliminating the influence of the external environment on the material cargo box airdrop process, and making the material cargo box accurately reach the target landing point. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 It is a flowchart of a first airdrop parachute control method provided by an embodiment of the present invention;

[0041] Figure 2 is a flow chart of a second airdrop parachute control method provided by an embodiment of the present invention;

[0042] Figure 3 It is a structural schematic diagram of an airdrop parachute control device provided by an embodiment of the present invention;

[0043] Figure 4 It is a schematic diagram of the architecture of a first airdrop parachute control device provided by an embodiment of the present invention;

[0044] Figure 5 It is a schematic diagram of the architecture of a second airdrop parachute control device provided by an embodiment of the present invention;

[0045] Figure 6 1 is a schematic diagram of the architecture of a third airdrop parachute control device provided by an embodiment of the present invention;

[0046] Figure 7 1 is a schematic diagram of the architecture of a fourth airdrop parachute control device provided by an embodiment of the present invention;

[0047] Figure 8 is a flow chart of a third airdrop parachute control method provided by an embodiment of the present invention;

[0048] Fig. 9 is a schematic diagram of a first airdrop parachute control method provided by an embodiment of the present invention;

[0049] Fig.10 is a schematic diagram of a second airdrop parachute control method provided by an embodiment of the present invention;

[0050] Fig.11 is a schematic diagram of a third airdrop parachute control method provided by an embodiment of the present invention;

[0051] Fig.12 is a schematic diagram of a fourth airdrop parachute control method provided by an embodiment of the present invention;

[0052] Fig.13 is a schematic diagram of a fifth airdrop parachute control method provided by an embodiment of the present invention;

[0053] Fig.14 is a schematic diagram of a sixth airdrop parachute control method provided by an embodiment of the present invention;

[0054] Fig.15 is a flow chart of a fourth airdrop parachute control method provided by an embodiment of the present invention;

[0055] Fig.16 It is a schematic diagram of the flow chart of the fifth airdrop parachute control device provided by an embodiment of the present invention;

[0056] Fig.17 1 is a schematic diagram of the architecture of a seventh airdrop parachute control device provided by an embodiment of the present invention;

[0057] Fig.18 It is a flow chart of the sixth airdrop parachute control method provided in an embodiment of the present invention.

[0058] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0059] 1. Parachute; 2. Parachute thrower; 3. Positioner; 4. Thruster; 41. First propulsion unit; 42. Second propulsion unit; 5. Controller; 6. Material container; 7. Altitude sensor; 8. Wireless communication module; 9. Gyroscope; 10. Accelerometer; 11. Geomagnetic sensor; 12. Power module. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0061] Unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as open inclusion, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "examples", "specific examples" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner, that is, although they may be carried in the embodiments or examples of the above terms due to reasons such as the order and position of appearance, it is not limited to that they can be carried in combination by one embodiment or example.

[0062] In the description of the present invention, it is necessary to understand that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do 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 understood as a limitation on the present disclosure.

[0063] In the description of the present invention, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, the meaning of "multiple" is two or more. In addition, for example, the same type of nouns may be described as two independent individuals by adding "A" and "B" at the end. In this case, the corresponding features defined as "A" and "B" are only used to distinguish the same type of individuals for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features.

[0064] In the description of the present invention, the expression "A and / or B" (where A and B are used to formally represent specific characteristic contents) will be involved, and the corresponding expressions include the following three combinations: only A, only B, and a combination of A and B.

[0065] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0066] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0067] Embodiment 1:

[0068] In the prior art, during an airdrop parachute process, materials are easily affected by the environment after being thrown out, causing the material landing point to deviate from the preset target landing point. In order to solve this problem, Embodiment 1 of the present invention provides an airdrop parachute control method, such as Figure 1 As shown, including:

[0069] In step 201, a target trajectory that enables the material container to land at the target landing point is determined based on the starting point position and the target landing point of the material container; the starting point position may be the airdrop position of the material container, or the starting position for starting to control the propulsion speed of the material container.

[0070] In step 202, the off-track distance and the track error angle of the material container relative to the target trajectory are determined according to the position of the material container.

[0071] In step 203, the propulsion speed of the cargo box is calculated based on the off-track distance and the track error angle, and the cargo box is propelled at the propulsion speed so as to approach the target trajectory and land at the target landing point according to the target trajectory. The propulsion speed is a vector, that is, it includes a propulsion rate and a propulsion direction. In actual use, propelling the cargo box at the propulsion speed often refers to controlling the propulsion speed of the propeller used to propel the cargo box, such as for a ducted propeller, it refers to controlling the fan speed of the ducted propeller.

[0072] This embodiment calculates the target trajectory of the material cargo box, uses the target trajectory as a reference, controls the material cargo box, and makes the material cargo box approach the target trajectory until it finally lands at the target landing point according to the target trajectory. This can eliminate the influence of the external environment on the material cargo box airdrop process and enable the material cargo box to accurately reach the target landing point.

[0073] In the actual application scenario, according to the starting point position and the target landing point of the cargo box, a target trajectory that enables the cargo box to land at the target landing point is determined, such as Figure 2 As shown, specifically including:

[0074] In step 301, the target track angle is calculated Calculate the first parameter

[0075] In step 302, the target trajectory is determined to be y=kx+b; wherein x0 is the horizontal coordinate of the starting point of the material cargo box, y0 is the vertical coordinate of the starting point of the material cargo box, x1 is the horizontal coordinate of the target landing point of the material cargo box, y1 is the vertical coordinate of the target landing point of the material cargo box, x is the horizontal coordinate of the corresponding point on the target trajectory, and y is the vertical coordinate of the corresponding point on the target trajectory.

[0076] It should be noted here that the starting point position, target landing point, target trajectory and position representations in the present embodiment are all determined with the earth's spherical surface as the reference plane, that is, it can be understood that each position representation is a mapping of the corresponding position in three-dimensional space on the earth's spherical surface, without considering the displacement change in the vertical direction of the material cargo box. The specific reference coordinate system is obtained by technical personnel in this field based on empirical analysis.

[0077] Wherein, the step of determining the deviation distance and the track error angle of the material container relative to the target trajectory according to the position of the material container specifically includes: calculating the deviation distance Calculate the track error angle Among them, x' is the horizontal coordinate of the current position of the material cargo box, y' is the vertical coordinate of the current position of the material cargo box, x1 is the horizontal coordinate of the target landing point of the material cargo box, y1 is the vertical coordinate of the target landing point of the material cargo box, k is the target track angle of the target trajectory, and b is the first parameter of the target trajectory.

[0078] In an optional implementation, the calculation of the propulsion speed of the cargo box according to the deviation distance and the track error angle specifically includes: calculating the propulsion speed of the cargo box Δδ=ΔZ×(k p ×d1+k i ×d)+k d ×(d1-d0)+k0; where ΔZ is the track error angle, d is the off-track distance, x0 is the horizontal coordinate of the starting point of the cargo box, y0 is the vertical coordinate of the starting point of the cargo box, x1 is the horizontal coordinate of the target landing point of the cargo box, y1 is the vertical coordinate of the target landing point of the cargo box, k is the target track angle of the target trajectory, b is the first parameter of the target trajectory, k p , k i , k d and k0 are preset coefficients.

[0079] Each preset coefficient is obtained by technicians in this field based on their experience and analysis of the demand for placing material containers. In actual use, k p Also called the proportional adjustment coefficient, k i Also known as the integral adjustment coefficient, k d It is also called a differential adjustment coefficient. In some embodiments, each preset coefficient can also be adjusted according to the environment in which the material container is located.

[0080] Embodiment 2:

[0081] Based on the airdrop parachute control method provided in Example 1, this embodiment also provides an airdrop parachute control device, such as Figure 3 and Figure 4 As shown, it includes a parachute 1, a parachute thrower 2, a locator 3, a thruster 4 and a controller 5; the parachute 1 is arranged above the material box 6 through the parachute thrower 2, and the thruster 4 is arranged on the side of the material box 6; the locator 3 is used to detect the position of the material box 6; the controller 5 sends a parachute throwing command to the parachute thrower 2, and the parachute thrower 2 is used to open the parachute 1 according to the parachute throwing command; the controller 5 is also used to control the propulsion speed of the thruster 4 using the airdrop parachute control method described in Example 1, so that the material box 6 lands to the target landing point.

[0082] In actual application scenarios, the propeller 4 is a differential propeller, and the differential propeller includes a first propulsion unit 41 and a second propulsion unit 42; the first propulsion unit 41 is arranged on a first side of the material cargo box 6, and the second propulsion unit 42 is arranged on a second side of the material cargo box 6, and the second side is a side opposite to the first side; Figure 3 As shown, the first propulsion unit 41 is arranged on the left side of the cargo box 6, and the second propulsion unit 42 is arranged on the right side of the cargo box 6. The control of the propulsion speed of the propeller 4 is specifically to control the fan speed difference of the differential propeller.

[0083] In a preferred embodiment, Figure 5 As shown, the device further includes a height sensor 7; the height sensor 7 is used to detect the height of the cargo box 6; the controller 5 is also used to send a parachute throwing instruction to the parachute throwing device 2 when the height of the cargo box 6 reaches a preset height. The preset height is obtained by those skilled in the art according to demand analysis.

[0084] This embodiment monitors the height of the material cargo box 6 and controls the parachute thrower 2 to release the parachute at a preset height, thereby increasing the freedom of the height of the material cargo box 6, and supports dropping the parachute after the material cargo box 6 has been thrown for a period of time, so that the material cargo box 6 is affected as little as possible by the environment during the period of time after being thrown.

[0085] In actual use, Figure 6 As shown, the device further includes a wireless communication module 8; the wireless communication module 8 is used to receive wireless signals, obtain the target landing point of the material container 6 from the wireless signals, and transmit the target landing point to the controller 5. The wireless signal carrying the target landing point can be emitted by a drone used to drop the material container 6.

[0086] In an actual application scenario, the device also includes one or more of a gyroscope 9, an accelerometer 10 and a geomagnetic sensor 11; the gyroscope 9 is used to measure the angular velocity of the material container 6; the accelerometer 10 is used to measure the linear acceleration of the material container 6; the geomagnetic sensor 11 is used to measure the geomagnetic field at the location of the material container 6; the controller 5 is also used to adjust the coefficient used in the control process of the thruster 4 according to one or more of the angular velocity, linear acceleration and geomagnetic field at the location of the material container 6. The coefficient referred to here can be k0, proportional adjustment coefficient k p , integral adjustment coefficient k i and the differential adjustment coefficient k d Specifically, the gyroscope 9 and the accelerometer 10 are used to determine the angular velocity and linear acceleration of the material container 6, thereby determining the posture of the material container 6, and the above coefficients are corrected according to the posture to make the above coefficients adapt to the landing process of the material container 6, so that the trajectory adjustment of the material container 6 can keep up with the landing process of the material container 6. And in actual use, the geomagnetic field is also used to identify the direction.

[0087] In actual use, Figure 7 As shown, the device also includes a power module 12, which is used to power the parachute thrower 2, the locator 3, the thruster 4 and the controller 5. In a preferred embodiment, the power module 12 also powers one or more devices in the altitude sensor 7, the wireless communication module 8, the gyroscope 9, the accelerometer 10 and the geomagnetic sensor 11. The power supply for each device can be directly powered by the power module 12, or it can be powered by the power module 12 through a corresponding circuit, or the power module 12 can power the controller 5, and the output of the corresponding output port of the controller 5 can power other devices. The power module 12 can include a lithium battery and a power management unit in actual use, and the power management unit completes the power extraction from the lithium battery, conversion and provides power distribution to each device. The device can also include a PWM output module, the input end of the PWM output module is connected to the corresponding output control port of the controller 5, and the output end of the PWM output module is connected to the control end of the thruster 4 to achieve control of the thruster 4.

[0088] In some specific application scenarios, the locator 3 is a global positioning system (GPS) module, the altitude sensor 7 is a barometric altimeter, the gyroscope 9 is a three-axis gyroscope, the accelerometer 10 is a three-axis accelerometer, and the geomagnetic sensor 11 is a three-axis geomagnetic sensor.

[0089] Embodiment 3:

[0090] In actual use, the drone usually needs to travel to a position relatively close to the target landing point to drop the cargo box. During the driving process, the drone may also be affected by the collision with birds, causing the drone to lose control and fail to reach the designated airdrop location of the cargo box. In order to solve this problem, this embodiment also provides an early warning of the risk of bird collision during the flight of the drone on the basis of embodiment 1, so that the drone operator can avoid or drive away birds according to the early warning. That is, before step 201, the airdrop parachute control method described in this embodiment includes: Figure 8 As shown, the method also includes:

[0091] In step 401, a drone carrying a cargo box of supplies flies to a designated airdrop location. During the flight of the drone, the drone detects surrounding birds and establishes a reachable set model of the bird's flight state based on the bird's movement data. The reachable set model of the flight state is used to reflect the locations that the birds can reach, that is, the range that is disturbed by the bird's flight.

[0092] In step 402, a flight model of the UAV is established, and the collision risk between the bird and the UAV is determined according to the flight state reachable set model and the flight model.

[0093] In step 403, an early warning is issued according to the collision risk; wherein, the reachable set model of the flight state of the bird includes a bird proximity layer and a bird collision layer located inside the bird proximity layer, and the flight model of the drone includes a drone proximity layer and a drone collision layer located inside the drone proximity layer; when the bird proximity layer is outside the drone proximity layer, it is considered that there is no collision risk, that is, it is safe; when the bird proximity layer is inside the drone proximity layer and the bird proximity layer, it is considered that there is a first-level collision risk, that is, there may be a bird strike risk; when the bird collision layer is inside the drone proximity layer and the bird collision layer is outside the drone collision layer, it is considered that there is a second-level collision risk, that is, the bird strike risk increases; when the bird proximity layer is inside the drone collision layer and the bird collision layer is inside the drone proximity layer, it is considered that there is a third-level collision risk, that is, there is a high probability of a bird strike risk; when the bird collision layer is inside the drone collision layer, it is considered that the danger is approaching and a bird strike is about to occur or has occurred.

[0094] The bird collision layer and the bird proximity layer are both within the range of an ellipsoid with the current position of the bird as the center, and the long radius of the bird collision layer is c'=kc, and the short radius of the bird collision layer is a'=ka; wherein c is the long radius of the bird proximity layer, a is the short radius of the bird collision layer, and k is a preset parameter obtained by those skilled in the art based on empirical analysis. The long radius c of the bird proximity layer and the short radius a of the bird proximity layer are obtained by those skilled in the art based on empirical analysis, specifically: images of various types of birds are collected in advance, and the motion data of each bird (including maximum flight speed, turning radius, maximum flight altitude, etc.) are analyzed to determine the long radius c of the corresponding bird proximity layer and the short radius a of the bird proximity layer, thereby generating a bird database, and the drone collects surrounding bird images through radar or camera, and matches them with the bird database to determine the corresponding bird collision layer and bird proximity layer.

[0095] The drone proximity layer and the drone collision layer are both represented as a rectangular area centered on the current position of the drone. The size of the rectangular area is obtained by technicians in this field based on the analysis of the drone's flight data, and the drone collision layer is located inside the drone proximity layer. In actual use, assuming that the length, width, and height of the smallest rectangular block where the drone is located are λx, λy, and λz respectively, then Fig. 9 As shown, 2λx, 2λy, and 2λz can be used as the length, width, and height of the UAV collision layer, respectively. Assuming that Sx, Sy, and Sz are the longitudinal, lateral, and vertical spacing standards, respectively, a rectangular block with a length, width, and height of 2Sx, 2Sy, and 2Sz can be made with the UAV as the center as the UAV as the adjacent layer.

[0096] The collision risks between birds and drones are shown in the following table:

[0097]

[0098]

[0099] Among them, a certain layer of birds is inside a certain layer of drones, which means that there is a spatial intersection between a certain layer of birds and a certain layer of drones, and a certain layer of birds is outside a certain layer of drones, which means that there is no spatial intersection between a certain layer of birds and a certain layer of drones. For example, taking the first-level risk as an example, the bird adjacent layer is inside the drone adjacent layer, which means that there is a spatial intersection between the bird adjacent layer and the drone adjacent layer; the bird adjacent layer is outside the drone collision layer, which means that there is no spatial intersection between the bird adjacent layer and the drone collision layer, and other situations are analogous, which will not be elaborated here.

[0100] like Fig.10 As shown in , there is no intersection between the bird proximity layer and the drone proximity layer, that is, the bird proximity layer is outside the drone proximity layer, which is a safe state at this time; Fig.11As shown in , the bird proximity layer is within the drone proximity layer, and the bird proximity layer is outside the drone collision layer, which is a level one risk; Fig.12 As shown in , the bird collision layer is within the drone proximity layer, and the bird collision layer is outside the drone collision layer, which is a secondary risk; Fig.13 As shown in , the bird proximity layer is within the drone collision layer, and the bird collision layer is within the drone proximity layer, which is a level 3 risk; Fig.14 As shown, the bird collision layer is within the drone collision layer, which is a dangerous approach state.

[0101] In actual application scenarios, such as Fig.15 As shown, the steps 401 to 403 are specifically performed as follows:

[0102] In step 501, the bird species around the drone flight area and the motion data of different birds are recorded in advance. The motion data includes one or more of the maximum flight speed, turning radius and maximum flight altitude. This step is to record the preliminary bird data, for example, the birds appearing around the drone flight area are recorded in the bird strike warning system database, and the motion data such as the maximum flight speed, turning radius, and maximum flight altitude of the birds are recorded.

[0103] In step 502, when an early warning is required, the bird species is identified by a detection device, and the motion data of the corresponding bird is read. The detection device includes one or more of a radar device and an optoelectronic device. This step performs bird species analysis, for example, bird species identification is performed by collecting bird data through radar and optoelectronic devices, and motion data of the identified bird is read.

[0104] In step 503, a reachable set modeling of the bird's flight state is performed based on the corresponding bird's motion data. This step performs probabilistic reachable set modeling of the bird's flight state, performs probabilistic reachable set modeling of bird flight, and constrains the reachable set model through the bird's motion data, converting the probability solution of bird flight into a convex optimization problem.

[0105] In step 504, the reachable set model is linearized and then solved to obtain the reachable set of the bird's flight state within time r. This step performs a probability reachability analysis of bird flight. In view of the uncertainty of bird flight and its susceptibility to external disturbances, the bird reachable set model (i.e., the bird's flight state reachable set model) is linearized, and a bird state parameter equation is established. By solving it, the bird's flight probability reachable set within time r can be obtained.

[0106] In step 505, the UAV Reich model (i.e., the flight model of the UAV) is established, and the reachable set of the bird flight state within a certain period of time is intersected with the UAV Reich model to obtain the bird strike warning result. This step performs bird strike conflict resolution, and the reachable set model and the UAV Reich model are conflict resolved to obtain the risk of bird strike events.

[0107] refer to Fig. 9 As shown, in one embodiment, the establishment of the UAV Reich model specifically includes: taking the UAV as the center, a cuboid area with dimensions of λx, λy, and λz is virtualized through the length, wingspan, and height of the UAV as the collision layer of the UAV, and the size of the UAV collision layer is larger than the size of the UAV, for example, twice as large as the UAV. Taking the UAV as the center, a cuboid with length, width, and height of Sx, Sy, and Sz is made as the adjacent layer of the UAV; Sx, Sy, and Sz can be determined according to longitudinal, lateral, and vertical spacing standards. Assume that the position of the UAV at time r is (x, y, z), at this time the UAV collision layer is λ(x, y, z), and the UAV adjacent layer is S(x, y, z).

[0108] In some embodiments, the method of obtaining the bird strike warning result by intersecting the reachable set of the bird flight state within a certain period of time with the Reich model of the drone specifically includes: assuming that the drone can avoid the bird risk by driving away or avoiding within time r, taking the reachable set R[0,r] of the bird at time r as the bird collision layer, and the reachable set R[0,2r] at time 2r as the bird proximity layer; calculating R[0,r]∩λ(x,y,z) to obtain whether the bird collision layer is within the drone collision layer; calculating R[0,r]∩S(x,y,z) to obtain whether the bird collision layer is within the drone proximity layer; calculating R[0,2r]∩λ(x,y,z) to obtain whether the bird proximity layer is within the drone collision layer; calculating R[0,2r]∩S(x,y,z) to obtain whether the bird proximity layer is within the drone collision layer; calculating R[0,2r]∩S(x,y,z) to obtain whether the bird proximity layer is within the drone proximity layer; the bird strike warning result can be obtained according to the calculation results.

[0109] refer to Fig.16 As shown in the figure, the early warning judgment process can be understood as the following steps:

[0110] In step 601, if the bird proximity layer is outside the drone proximity layer, it is determined to be safe. Fig.10 As shown, the risk criteria at this time are: R[0,2r] is outside the drone's proximity layer; the risk level is safe; the warning color is: none; and the impact on the drone is: no impact.

[0111] In step 602, if the bird proximity layer is within the drone proximity layer and the bird collision layer is outside the drone proximity layer, it is determined to be a level one risk. Fig.11As shown in the figure, the risk criteria at this time are: R[0,2r] is within the drone proximity layer, and R[0,r] is outside the drone proximity layer; the risk level is level one risk; the warning color is light yellow; the impact on the drone is: there may be a risk of bird strike, and a warning is required.

[0112] In step 603, if the bird proximity layer is within the drone proximity layer and the bird collision layer is within the drone proximity layer, it is determined to be a level 2 risk. Fig.12 As shown in the figure, the risk criteria at this time are: R[0,2r] is within the drone proximity layer, and R[0,r] is within the drone proximity layer; the risk level is level 2 risk; the warning color is yellow; the impact on the drone is: the risk of bird strikes increases and needs to be driven away in time.

[0113] In step 604, if the bird proximity layer is within the drone collision layer, and the bird collision layer is within the drone proximity layer, it is determined to be a level 3 risk. Fig.13 As shown, the risk criteria at this time are: R[0,2r] is in the drone collision layer, and R[0,r] is in the drone proximity layer; the risk level is level three risk; the warning color is: orange; the impact on the drone is: there is a high risk of bird strike, and emergency avoidance is required.

[0114] In step 605, if the bird collision layer is within the drone collision layer, it is determined to be dangerously close. Fig.14 As shown, the risk criteria at this time are: R[0,r] is within the UAV collision layer; the risk level is dangerous approach; the warning color is: red; the impact on the UAV is: a bird strike is about to occur or has occurred.

[0115] In summary, the embodiments of the present invention provide a bird strike warning method and system based on accessibility analysis, which analyzes the collision risk between birds and drones by constructing a reachable set, takes into account the movement characteristics of birds, and improves the accuracy of judging the bird strike risk. Specifically, the embodiments of the present invention analyze the accessibility of different types of birds and combine it with the drone Reich model to perform bird strike risk analysis, which can effectively calculate the bird collision risk in the drone flight area and provide early warning; by analyzing different birds, early warning can be effectively provided based on the flight characteristics of different birds, with higher accuracy and safety.

[0116] Based on the above method, the present invention also provides more detailed examples to describe the scheme.

[0117] First, the preliminary bird data entry was carried out: in the observation area with a radius of 2km in the drone flight area, bird observation was carried out every day using radar, photoelectric, manual and other detection methods to obtain daily bird information in the area and store at least 90 days of bird information. The bird information of the last 90 days was counted to obtain the bird species in the clear area of ​​the drone flight area within 90 days and the corresponding maximum flight speed, turning radius, maximum flight altitude and other movement data.

[0118] When an early warning is required, bird species analysis is performed: bird species are identified through radar and photoelectric data, and the identified birds are compared with the stored data to extract the corresponding movement data.

[0119] Next, we model the probability reachable set of bird flight. Bird flight is easily affected by external environmental disturbances and the uncertainty of the bird's flight purpose, so its flight state shows a highly nonlinear characteristic. Therefore, birds are a nonlinear system.

[0120] Since the bird flight system is a nonlinear system, it can be expressed as follows: ; Where t is time, x is the state variable of the bird, u is the flight input of the bird, and v is the interference of the outside world on the bird. The flight input u of the bird is determined by the motion data of common local birds, such as: maximum flight speed, turning radius, climbing rate, maximum flight acceleration and maximum flight altitude, etc.; the interference of the outside world is mainly generated by the protected object drone. The drone will generate noise to scare the birds, and the birds will deviate from the current position of the drone due to being scared. At this time, the interference of the bird's movement is determined by the degree of its own fright, and the value of v is also determined by the bird's motion data, such as: maximum flight speed, turning radius, climbing rate and maximum flight altitude, etc. The motion data of the bird is also the nonlinear motion characteristics of the bird.

[0121] Let x(t)∈X, u(t)∈U(t),v(t)∈V, X, U(t), V are all convex and compact sets. The sum of the bird's flight input u and the external interference v will not exceed the bird's inherent motion data, so u(t)+v(t)∈U(t);

[0122] The reachable set of the bird's flight state is defined as: R[υ] = R(υ, t0, X0); this formula represents the set of states that can be reached at time v for a system with X0 as the initial state and t0 as the initial moment. We can use the reachable set to reflect the locations that birds can reach at different times, and thus derive the range of interference caused by birds in flight conflicts.

[0123] Assume that the support function of the reachable set is: ρ(l|R[υ])=max{<l,x> |x∈R[υ],l∈R[υ]}, l,x are both vectors.

[0124] Next, the bird flight probability accessibility analysis was conducted.

[0125] Because the flying state of birds is easily affected by external interference and the flying method of birds is flexible, birds may fly in any direction. Birds may exhibit various flight modes such as straight line uniform speed flight, straight line accelerated flight, decelerated flight, circular flight, U-turn flight, landing, climbing, etc., and the horizontal acceleration is greater than the vertical acceleration.

[0126] According to the flight pattern of birds, this embodiment constructs an ellipsoid reachable set to represent the reachable range of birds. The calculation complexity of the ellipsoid is small, the accuracy is high, and the conservatism is small.

[0127] If the ellipsoid model is used to analyze the nonlinear system, the system needs to be linearized; that is, the bird flight system is linearized, and the linearized system is:

[0128] x(t)∈X, u(t)∈U(t),v(t)∈V;

[0129] in,

[0130] Combination The support function ρ(l|R[υ]) of the reachable set can be expressed as:

[0131]

[0132] Where l∈R[υ], s∈[0,υ]; R[υ] is the set of states that can be reached from the initial time 0 at time t=υ; Φ(t,s) is the system The transfer matrix satisfies And Φ(s,s)=I;

[0133] Assume that the reachable set is an ellipsoid, let c x ,M x is the center and boundary of the set, then x∈X=E(c x ,M x );

[0134]

[0135] The support function can be expressed as<l,x> ≤ <l,c X >+ <l,M X l> 1 / 2 ;

[0136] The support function of the reachable set R[υ] can be further expressed as the initial set, control set, and interference set using center and shape matrices:

[0137]

[0138] Where l∈R[υ], s∈[0,υ]; R[υ] is the set of states that can be reached from the initial time 0 at time t=υ; Φ(t,s) is the system The transfer matrix satisfies And Φ(s,s)=I;c x0 is the center of the initial set, M x0 is the boundary of the initial set; U is the flight input set of birds, and V is the interference set of the outside world on birds.

[0139] Finally, the reachable set of birds in time r is represented by the sum of homogeneous solutions and special solutions:

[0140]

[0141] in is a homogeneous solution of a reachable set, is a special solution of the reachable set. The specific solution process is the existing technology and will not be repeated here.

[0142] The reachable set model and the drone Reich model are used to resolve conflicts and determine whether birds may pose a threat to drones within time r. The Reich model is an internationally used drone collision model.

[0143] The basic principle of the Reich model: Let the length, wingspan, and height of the drone in the route be λx, λy, and λz respectively. With drone A as the center, a cuboid area with 2λx, 2λy, and 2λz in the longitudinal, transverse, and vertical directions is virtualized as the drone collision layer; let Sx, Sy, and Sz be the longitudinal, lateral, and vertical spacing standards respectively, and make a cuboid with a length, width, and height of 2Sx, 2Sy, and 2Sz with drone A as the center, which is the drone adjacent layer. Take drone B as a particle. When drone B enters the adjacent layer, there is a collision risk. When drone B enters the collision layer, the two will collide.

[0144] When the dangerous target is a bird, the interval standard and collision distance between drones cannot be applied. The bird strike risk can be calculated by constructing collision layers and proximity layers for drones and birds respectively. The drone collision layer is a cuboid area centered on drone A, using the length, wingspan, and height of the drone as the drone collision layer. A cuboid with a length, width, and height of Sx, Sy, and Sz, centered on drone A, is the drone proximity layer.

[0145] In order to analyze the collision risk between birds and drones, the collision layer and proximity layer of birds are constructed. Assuming that the drone can avoid the risk of birds by driving away or avoiding them within time r, the reachable set R[0,r] of bird B at time r is taken as the bird collision layer. When the bird collision layer is inside the drone collision layer, it means that a dangerous approach has occurred and there is a risk of bird strike. The reachable set R[0,2r] at time 2r is taken as the bird proximity layer. When the bird proximity layer is outside the drone proximity layer, there is no collision risk between drone A and bird B; when the bird proximity layer is close to the drone proximity layer, the risk of bird strike will increase.

[0146] Assume that the position of the drone at time r is (x, y, z), the collision layer of the drone is λ(x, y, z), and the proximity layer of the drone is S(x, y, z). Specifically, calculate R[0,r]∩λ(x,y,z) to obtain whether the bird collision layer is within the drone collision layer; calculate R[0,r]∩S(x,y,z) to obtain whether the bird collision layer is within the drone proximity layer; calculate R[0,2r]∩λ(x,y,z) to obtain whether the bird proximity layer is within the drone collision layer; calculate R[0,2r]∩S(x,y,z) to obtain whether the bird proximity layer is within the drone proximity layer; if the bird proximity layer is outside the drone proximity layer, it is judged to be safe; if the bird proximity layer is within the drone proximity layer and the bird collision layer is outside the drone proximity layer, it is judged to be a first-level risk; if the bird proximity layer is within the drone proximity layer and the bird collision layer is within the drone proximity layer, it is judged to be a second-level risk; if the bird proximity layer is within the drone collision layer and the bird collision layer is within the drone proximity layer, it is judged to be a third-level risk; if the bird collision layer is within the drone collision layer, it is judged to be dangerous approach.

[0147] In summary, the embodiment of the present invention analyzes the collision risk between birds and drones by constructing a reachable set, taking into account the movement characteristics of birds, and improving the accuracy of judging the risk of bird strikes. Specifically, the embodiment of the present invention analyzes the reachability of different types of birds and combines it with the drone Reich model to perform bird strike risk analysis, which can effectively calculate the risk of bird collision in the drone flight area and provide early warning; by analyzing different birds, early warning can be effectively provided based on the flight characteristics of different birds, with higher accuracy and safety.

[0148] In addition, for the special scenario of bird strike, this embodiment uses the ellipsoid reachable set model to analyze the probability reachability of bird flight, and also fine-tunes the Reich model, using the reachable set R[0,r] as the bird collision layer and R[0,2r] as the bird proximity layer. The risk calculation is performed using a geometric calculation intersection method, and the calculation interaction of the Reich model and the reachable set is optimized and innovated for the special scenario of bird strike, so as to provide an early warning of the risk of bird collision during the flight of the drone, thereby facilitating the drone operator to avoid or drive away birds according to the early warning, so as to reach the designated airdrop location for the delivery of material cargo boxes, that is, after arriving at the designated airdrop location, the method described in Example 1 is executed.

[0149] Embodiment 4:

[0150] like Figure 3 and Fig.17 As shown, the precise parachute control device in the drone airdrop includes: a parachute 1; a parachute thrower 2; a parachute attitude control unit; a differential propeller (i.e., the propeller 4 in Example 2); a material cargo box 6; the parachute attitude control unit includes: a microcontroller unit (MCU) central processing unit (i.e., the controller 5 in Example 2), a three-axis gyroscope (i.e., the gyroscope 9 in Example 2), a three-axis accelerometer (i.e., the accelerometer 10 in Example 2), a three-axis geomagnetic sensor (i.e., the geomagnetic sensor 11 in Example 2), a barometric altimeter (i.e., the altitude sensor 7 in Example 2), a GPS module (i.e., the locator 3 in Example 2), a wireless communication module 8, a power module 12 (including a lithium battery and a power management module) and a PWM output module.

[0151] The cargo box 6 is used to load airdropped cargo, and the parachute thrower 2 is installed directly above the cargo box 6. When the drone performs the throwing action, the parachute thrower 2 will receive the parachute throwing command from the parachute attitude control unit 3, and the parachute 1 will be ejected and then deployed. At the same time, the parachute attitude control unit 3 controls the differential propeller to adjust the flight descent attitude according to the current landing trajectory and the orientation of the target landing point, thereby realizing the precise control of the parachute trajectory of the cargo box 6 and falling to the target point.

[0152] The differential propeller adopts a ducted fan mode, which can effectively avoid the entanglement of the parachute rope. The differential propeller is placed on the left and right sides of the material cargo box 6. The ducted fan supports forward and reverse bidirectional propulsion. The parachute attitude control unit controls the speed and direction of the ducted fans on the left and right sides of the differential propeller to control the flight attitude of the material cargo box. The lithium battery is placed on the top of the material cargo box 6 to provide power for the parachute attitude control unit 3 and the differential propeller.

[0153] The MCU central processing unit is used to collect data from various sensors, solve flight attitude, calculate the optimal control strategy, and execute control PWM output. The MCU central processing unit obtains real-time values ​​through the three-axis gyroscope, three-axis accelerometer, and three-axis geomagnetic sensor, and solves the current flight attitude through the quaternion method, including direction angle, pitch angle, roll angle, and speed. The current position coordinates and altitude are obtained through the barometric altimeter and GPS module. The three-axis gyroscope, three-axis accelerometer, and three-axis geomagnetic sensor are also collectively referred to as Inertial Measurement Unit (IMU) sensors.

[0154] The wireless communication module 8 receives the location information of the target landing point sent by the drone before the airdrop. When the drone performs the airdrop operation, the wireless communication module 8 also receives the airdrop completion message sent by the drone, and then the MCU central processing unit (i.e., the controller 5 in Example 1) executes the parachute throwing action on the parachute throwing device 2 through the PWM output module. The wireless communication module 8 needs to maintain smooth communication from the time when the drone airdrop action is completed and the entire device is in a free fall state to the time when the parachute 1 is thrown out and unfolded.

[0155] The PWM output module receives control from the MCU central processing unit and generates three PWM control signals, which are output to the left and right duct fans of the parachute ejector and the differential propeller respectively.

[0156] The power management module takes power from the lithium battery, converts it, and provides power distribution to each module inside the parachute attitude control unit.

[0157] like Fig.18 As shown, the precise parachute control method in the drone airdrop includes the following steps:

[0158] In step 701, the drone sends the coordinate information of the target landing point to the parachute attitude control unit and then performs the throwing operation. After receiving the throwing instruction, the parachute attitude control unit immediately controls the parachute thrower 2 to automatically open the parachute.

[0159] In step 702, the parachute attitude control unit calculates the distance and direction between the current position and the target landing point in real time based on the received target landing point coordinate information, using the built-in GPS and barometric altimeter, and simultaneously calculates the current flight attitude based on the built-in three-axis gyroscope, three-axis accelerometer, and three-axis geomagnetic sensor.

[0160] In step 703, the parachute attitude control unit calculates the predetermined track angle φ according to the current position and the target landing point position, and simultaneously calculates the heading angle ψ according to the flight attitude. By calculating and comparing the difference between the heading angle ψ and the track angle φ, the PID algorithm is used to control the PWM output to drive the left and right actuators, so that the landing track of the cargo box 6 gradually reaches the predetermined track (i.e., the target track in Example 1).

[0161] The entire device will go through two main control stages during the parachute control process: track preprocessing and track calibration. After the parachute 1 is deployed and enters the parachute control flight, the parachute attitude control unit will continuously compare the heading angle with the predetermined track angle to determine whether the parachute flight trend is close to the predetermined track, so as to carry out the next step of control. Since the moment when the entire device enters the parachute control flight may deviate greatly from the predetermined track, the control strategy of the track preprocessing part uses the open-loop part of the PID control, that is, no error feedback calculation is performed, and a larger control force is used to enable the entire device to enter the track calibration part as soon as possible.

[0162] After completing the track preprocessing, the parachute flight trend of the entire device is mainly to approach the predetermined track. At this time, the control logic enters the track calibration processing part to ensure that the entire device can smoothly enter the predetermined route. The design of the track calibration part is based on the great circle route control method. The GPS module is used to measure the current position of the entire device in real time, and the lateral deviation of the entire device from the predetermined track and the rate of change of the lateral deviation can be obtained. According to the lateral deviation and the rate of change of the lateral deviation, the command control differential thruster is generated to gradually approach the predetermined track and finally eliminate the lateral deviation.

[0163] The track calibration part mainly completes the navigation control law design of the entire device, that is, determines the speed difference of the left and right duct fans of the differential propulsor by calculating the horizontal distance that the entire device deviates from the route.

[0164] 1) Predetermine the track angle k, where (x0, y0) is the starting point position coordinate, (x1, y1) is the target point position coordinate, and the track angle k is calculated by the following formula:

[0165]

[0166] After the predetermined track angle k is determined, it can be obtained through the route equation y=kx+b, where b is determined by the following formula:

[0167]

[0168] 2) Calculate the horizontal deviation between the current position and the predetermined route (i.e., the deviation distance in Example 2), the predetermined track angle k (i.e., the target track angle in Example 2), and after the parameters of the route are determined, the horizontal deviation of the predetermined route of the entire device can be obtained:

[0169]

[0170] 3) The size and direction of the fan speed difference are related to the horizontal speed v, yaw distance d and track error angle ΔZ of the entire device at that time. Its control law can be designed using the yaw distance d and the speed component dv of the horizontal route of the entire device speed:

[0171] Δδ=ΔZ×(k p ×d1+k i ×d)+k d ×(d1-d0)+k0

[0172] In the above formula, Δδ is the speed difference of the ducted fan, and its left deviation is positive and right deviation is negative; the track error angle ΔZ is obtained by subtracting the actual flight track angle from the predetermined track angle:

[0173]

[0174] When the entire device deviates to the right side of the route, the track error angle ΔZ is negative, otherwise it is positive; if the component dv of the device's flight speed parallel to the route is used as the differential component of the control law calculation, the calculation is more complicated, so here (d1-d0) is used as the differential component of the control law adjustment; k p is the proportional adjustment coefficient, k i is the integral adjustment coefficient, k d are differential adjustment coefficients. They are constants adjusted according to actual conditions in the design of PID control law.

[0175] This embodiment improves the airdrop parachute control device, and the improved airdrop parachute control device includes a parachute attitude control unit, a parachute thrower, a differential propeller, a material cargo box and a lithium battery. The parachute thrower is placed in the middle of the top of the material cargo box, and the parachute attitude control unit and the lithium battery are placed next to it. The differential propeller is placed on the left and right sides of the material cargo box. When the drone flies above the target landing point, the position information of the target landing point is sent to the parachute attitude control unit, and then the drone throws the material cargo box out. After the parachute attitude control unit detects the free fall, it immediately controls the parachute thrower to eject the parachute, and the material cargo box enters the free parachute process. The parachute attitude control unit calculates the current position of the material cargo box through the built-in GPS and IMU sensors, and then calculates the distance and azimuth difference between the current position and the target landing point according to the received landing point position information. At this time, the parachute attitude control unit starts the differential propeller, controls the rotation speed of the left and right propellers through the PID control algorithm, and then controls the direction and horizontal speed of the material box falling, and finally realizes the precise control of the parachute trajectory of the material cargo box and lands at the target point position.

[0176] This embodiment can effectively solve the problem that the current parachute airdrop process of drones is easily affected by factors such as the wind speed and wind direction of the on-site environment, resulting in a large deviation between the actual landing position and the target landing point. That is, this embodiment solves the shortcomings of the traditional parachute material drop process of drones that the flight trajectory cannot be controlled and is greatly affected by the environmental wind speed and wind direction, ensuring that the airdropped materials can eventually land at the target point. In addition, the parachute attitude control unit has built-in GPS and IMU sensors, and the PID control parameters can be dynamically adjusted according to the size and weight of the material cargo box, which can realize accurate parachute delivery of materials of different sizes and weights, and has high adaptability.

[0177] It is worth noting that the information interaction, execution process, etc. between the modules and units within the above-mentioned devices and systems are based on the same concept as the processing method embodiment of the present invention. The specific contents can be found in the description of the method embodiment of the present invention and will not be repeated here.

[0178] A person skilled in the art may understand that all or part of the steps in the various methods of the embodiments may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, and the storage medium may include: a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, etc.

[0179] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An airdrop parachute control method, characterized in that: include: According to the starting point position and the target landing point of the cargo box, a target trajectory is determined that enables the cargo box to land at the target landing point; Determine the deviation distance and track error angle of the cargo box relative to the target trajectory according to the position of the cargo box; The propulsion speed of the cargo box is calculated according to the deviation distance and the track error angle, and the cargo box is propelled at the propulsion speed so as to approach the target trajectory and land at the target landing point according to the target trajectory.

2. The airdrop parachute control method according to claim 1, characterized in that: Determining a target trajectory that enables the material cargo box to land at the target landing point according to the starting point position and the target landing point of the material cargo box specifically includes: Calculate target track angle Calculate the first parameter Determine the target trajectory as y=kx+b; wherein x0 is the horizontal coordinate of the starting point of the material cargo box, y0 is the vertical coordinate of the starting point of the material cargo box, x1 is the horizontal coordinate of the target landing point of the material cargo box, y1 is the vertical coordinate of the target landing point of the material cargo box, x is the horizontal coordinate of the corresponding point on the target trajectory, and y is the vertical coordinate of the corresponding point on the target trajectory.

3. The airdrop parachute control method according to claim 1, characterized in that: Determining the deviation distance and track error angle of the material container relative to the target trajectory according to the position of the material container specifically includes: Calculate the deviation Calculate the track error angle Among them, x' is the horizontal coordinate of the current position of the material cargo box, y' is the vertical coordinate of the current position of the material cargo box, x1 is the horizontal coordinate of the target landing point of the material cargo box, y1 is the vertical coordinate of the target landing point of the material cargo box, k is the target track angle of the target trajectory, and b is the first parameter of the target trajectory.

4. The airdrop parachute control method according to claim 1, characterized in that: The calculation of the propulsion speed of the cargo box according to the deviation distance and the track error angle specifically includes: Calculate the propulsion speed of the cargo box Δδ=ΔZ×(k p ×d1+k i ×d)+k d ×(d1-d0)+k0; Wherein, ΔZ is the track error angle, d is the off-track distance, x0 is the horizontal coordinate of the starting point of the cargo box, y0 is the vertical coordinate of the starting point of the cargo box, x1 is the horizontal coordinate of the target landing point of the cargo box, y1 is the vertical coordinate of the target landing point of the cargo box, k is the target track angle of the target trajectory, b is the first parameter of the target trajectory, k p , k i , k d and k0 are preset coefficients.

5. An airdrop parachute control device, characterized in that: It comprises a parachute (1), a parachute ejector (2), a positioner (3), a propeller (4) and a controller (5); The parachute (1) is arranged above the material cargo box (6) through a parachute thrower (2), and the propeller (4) is arranged on the side of the material cargo box (6); The locator (3) is used to detect the position of the material container (6); The controller (5) sends a parachute throwing instruction to the parachute throwing device (2), and the parachute throwing device (2) is used to open the parachute (1) according to the parachute throwing instruction; The controller (5) is also used to control the propulsion speed of the propeller (4) using the airdrop parachute control method described in any one of claims 1 to 4, so that the material container (6) lands at a target landing point.

6. The airdrop parachute control device according to claim 5, characterized in that: The propeller (4) is a differential propeller, and the differential propeller comprises a first propulsion unit (41) and a second propulsion unit (42); The first propulsion unit (41) is arranged on a first side of the material cargo box (6), and the second propulsion unit (42) is arranged on a second side of the material cargo box (6), wherein the second side is a side opposite to the first side; The control of the propulsion speed of the propeller (4) is specifically to control the fan speed difference of the differential propeller.

7. The airdrop parachute control device according to claim 5, characterized in that: The device also includes a height sensor (7); The height sensor (7) is used to detect the height of the material container (6); The controller (5) is also used to send a parachute throwing instruction to the parachute throwing device (2) when the height of the material cargo box (6) reaches a preset height.

8. The airdrop parachute control device according to claim 5, characterized in that: The device also includes a wireless communication module (8); The wireless communication module (8) is used to receive wireless signals, obtain the target landing point of the material container (6) from the wireless signals, and transmit the target landing point to the controller (5).

9. The airdrop parachute control device according to claim 5, characterized in that: The device further comprises one or more of a gyroscope (9), an accelerometer (10) and a geomagnetic sensor (11); The gyroscope (9) is used to measure the angular velocity of the material container (6); The accelerometer (10) is used to measure the linear acceleration of the material container (6); The geomagnetic sensor (11) is used to measure the geomagnetic field at the location where the material container (6) is located; The controller (5) is also used to adjust the coefficients used in the control process of the thruster (4) according to one or more of the angular velocity, linear acceleration of the material container (6) and the geomagnetic field at the location where the material container (6) is located.

10. The airdrop parachute control device according to claim 5, characterized in that: The device also includes a power module (12), and the power module (12) is used to supply power to the parachute ejector (2), the positioner (3), the propeller (4) and the controller (5).

Images