Flying object, control method and program

Abstract

To land a flying object in a stable posture, for example.SOLUTION: A flying object comprises a plurality of motors and a control unit which controls the rotational speeds of the plurality of motors. The control unit sets a horizontal ground speed at a landing operation starting point on the basis of wind information containing information on a wind direction and a wind speed, and controls a decrease in a descending speed between the landing operation starting point and a landing point.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to an aircraft, a control method, and a program. [Background technology]

[0002] In recent years, unmanned autonomous flying objects known as UAVs (Unmanned Aerial Vehicles) or drones (hereinafter referred to as drones as appropriate) have been used in a variety of situations, such as various types of photography and observation, disaster relief, etc. Accordingly, various control methods for drones have been proposed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-52341 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, the attitude of a drone when landing is easily affected by wind, so it is desirable to control the drone so that it can land in a stable attitude even when affected by wind.

[0005] The present disclosure has been made in consideration of the above-mentioned points, and one of its objectives is to provide an aircraft, a control method, and a program that can be controlled to land in a stable attitude even when affected by wind. [Means for solving the problem]

[0006] The present disclosure provides, for example, A plurality of motors; a control unit that controls the rotation speed of the plurality of motors, The control unit receives wind information including information on wind direction and wind speed. Under the wind conditions, the horizontal ground speed at the landing point is set to 0 when the descent speed is reduced at a constant rate from the start of the landing operation to the landing point.Set the horizontal ground speed at the point where the landing operation starts, and set the descent speed from the point where the landing operation starts to the landing point. At a certain rate Control to reduce It is a flying object.

[0007] The present disclosure provides, for example, A control unit controls the rotation speed of the multiple motors, The control unit receives wind information including information on wind direction and wind speed. Under the wind conditions, the horizontal ground speed at the landing point is set to 0 when the descent speed is reduced at a constant rate from the start of the landing operation to the landing point. Set the horizontal ground speed at the point where the landing operation starts, and set the descent speed from the point where the landing operation starts to the landing point. At a certain rate Control to reduce A method for controlling an aircraft.

[0008] The present disclosure provides, for example, A control unit controls the rotation speed of the multiple motors, The control unit receives wind information including information on wind direction and wind speed. Under the wind conditions, the horizontal ground speed at the landing point is set to 0 when the descent speed is reduced at a constant rate from the start of the landing operation to the landing point. Set the horizontal ground speed at the point where the landing operation starts, and set the descent speed from the point where the landing operation starts to the landing point. At a certain rate Control to reduce This is a program that causes a computer to execute a method for controlling an aircraft. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram to be referred to when explaining issues to be considered in the embodiment. [Figure 2] FIG. 2 is a diagram to be referred to when explaining issues to be considered in the embodiment. [Figure 3] FIG. 3 is a diagram that will be referred to when explaining the outline of the embodiment. [Figure 4] FIG. 4 is a diagram that will be referred to when explaining the outline of the embodiment. [Figure 5] FIG. 5 is a diagram that will be referred to when explaining the outline of the embodiment. [Figure 6] 6A to 6C are diagrams to be referred to when explaining an example of a method for estimating wind information. [Figure 7] FIG. 7 is a block diagram illustrating an example of the configuration of a drone according to the first embodiment. [Figure 8] FIG. 8 is a flowchart illustrating a flow of processing performed by the drone according to the first embodiment. [Figure 9] FIG. 9 is a block diagram illustrating an example of the configuration of a drone according to the second embodiment. [Figure 10] FIG. 10 is a flowchart illustrating a flow of processing performed by the drone according to the second embodiment. [Figure 11] FIG. 11 is a flowchart illustrating a flow of processing performed by a drone according to the third embodiment. [Figure 12] FIG. 12 is a block diagram illustrating an example of the configuration of a drone according to the fourth embodiment. [Figure 13] FIG. 13 is a flowchart illustrating a flow of processing performed by a drone according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The description will be made in the following order. <Issues to be considered in the implementation> <Outline of the embodiment> First Embodiment <Second embodiment> <Third embodiment> <Fourth embodiment> <Modification> The embodiments and the like described below are preferred specific examples of the present disclosure, and the contents of the present disclosure are not limited to these embodiments and the like.

[0011] <Issues to be considered in the implementation> First, in order to facilitate understanding of the present disclosure, issues to be considered in the embodiments will be described with reference to FIGS.

[0012] FIG. 1 is a schematic diagram illustrating the landing of a drone 1. In the example shown in FIG. 1, wind is blowing from left to right as viewed in the drawing. For the drone 1 to land stably, it is desirable for the drone 1's horizontal ground speed to be zero or close to zero when landing. When descending vertically, one possible method is to fly the drone 1 in the opposite direction to the wind at the same speed as the wind to achieve zero horizontal ground speed near the ground. This control causes the drone 1 to tilt upwind (the state indicated by reference symbols A1 and A2 in FIG. 1). Then, as the drone approaches the ground, the side of the drone 1 closest to the ground experiences a large ground effect, generating a rotational moment (the state indicated by reference symbol A3 in FIG. 1). The rotational moment makes it difficult to control the drone 1's attitude. Furthermore, since the drone 1 lands tilted, there is a risk that the drone 1 may tip over during landing (the state indicated by reference symbol A4 in FIG. 1).

[0013] Therefore, as shown in FIG. 2, one possible control method is to descend the drone 1 vertically (the state indicated by reference symbols A5 and A6 in FIG. 2), and then level the drone 1 as it approaches the ground (the state indicated by reference symbol A7 in FIG. 2). However, if the attitude of the drone 1 changes significantly near the ground, the attitude of the drone 1 is likely to become unstable. Furthermore, if the drone 1 is blown by the wind as the attitude of the drone 1 changes, the drone 1 may have a horizontal ground speed, which could make the landing unstable. In light of the above points, in an embodiment of the present disclosure, control is performed to ensure a stable landing of the drone 1.

[0014] <Outline of the embodiment> Next, an overview of embodiments of the present disclosure will be described. Note that this description will also include an explanation of matters common to each embodiment.

[0015] [Outline of the embodiment] FIG. 3 is a diagram for explaining an overview of an embodiment. The drone 1 is assumed to land at a landing point LP shown in FIG. 3. The landing point LP may be a position with preset coordinates, or may be a position with coordinates instructed by an appropriate device on the ground (hereinafter, appropriately referred to as a ground station). A transition point PA is set at an appropriate position in space, as shown in FIG. 3. The transition point PA is a point located above the landing point LP, and is the point at which the drone starts its landing operation. The drone 1, which is present at a position in space (above the transition point PA), decides to land. For example, the drone 1 decides to land in response to a remote control instruction, completion of a given task, a decrease in remaining battery capacity, a failure of a sensor possessed by the drone 1, the occurrence of a communication failure, or the like.

[0016] When landing is determined, the drone 1 acquires wind information. The wind information includes information about winds that affect the flight of the drone, including information about wind direction and wind speed. Such wind information may be acquired by a sensor included in the drone 1, or may be transmitted to the drone 1 from a ground station.

[0017] The drone 1 determines a landing approach sequence and a touchdown sequence. The landing approach sequence is control of the drone 1 performed from its current position (PB in FIG. 3 ) to the transition point PA. A specific example of the landing approach sequence is information indicating the time-series positions of the drone 1 from the current position PB to the transition point PA and the speed of the drone 1 at each position. Here, for the drone 1 to land stably, it is desirable for the horizontal ground speed at the time of landing to be approximately zero. "Approximately zero" means that the horizontal ground speed is zero or close enough to zero that the drone 1 can land safely. Therefore, in the landing approach sequence, at the transition point PA, control is performed to give the drone 1 a horizontal ground speed in advance such that the horizontal ground speed of the drone 1 at the landing point LP will be approximately zero. Specifically, the rotation speeds of multiple motors of the drone are controlled to achieve a set horizontal ground speed. The movement trajectory of the drone 1 from the current position PB to the transition point PA and the horizontal ground speed at each position are calculated so that a predetermined horizontal ground speed is given at the transition point PA, and the operation of the drone 1 is appropriately controlled based on the calculation results.

[0018] The touchdown sequence is a control of the drone 1 performed from the transition point PA to the landing point LP. When the drone 1 detects that it has passed the transition point PA, the drone 1 is controlled by the touchdown sequence. The touchdown sequence is, for example, information indicating the time series of positions until landing and the vertical speed at each position. The touchdown sequence specifies control to keep the drone 1 in a horizontal position or the horizontal ground speed at each position. By being controlled based on the touchdown sequence, the drone 1 descends toward the landing point LP, as shown in Figure 3. Because the drone 1's body is kept horizontal and the horizontal ground speed at landing is approximately zero, tilting of the drone 1's body can be prevented, allowing the drone 1 to land in a stable position.

[0019] [Matters common to all embodiments] (Regarding transition altitude) Next, matters common to each embodiment will be described. First, the transition altitude H, which is the height from the landing point LP to the transition point PA, will be described. The coordinates of the landing point LP are expressed as (x, y, 0), and the coordinates of the transition point PA are expressed as (x', y', H) (see FIG. 4).

[0020] Transition altitude H, descent speed of drone 1 v z (t), the time from the transition point t, the time it takes to land t t , the downward velocity of drone 1 at the transition point PA (hereinafter referred to as the transition descent velocity) v z (0)=v zH , the downward velocity of drone 1 at the time of landing (hereinafter referred to as the landing descent velocity) v z (t t )=v z0 Then (see FIG. 4), the relationship between these is expressed by the following Equation 1.

[0021] [Formula 1] TIFF0007754245000001.tif13163

[0022] In particular, if the descent velocity decreases at a constant rate, the above integral can be solved analytically as shown in Equation 2 below.

[0023] [Formula 2] TIFF0007754245000002.tif7163

[0024] The landing descent speed is set to a speed below the descent speed at which a safe landing is possible. If the landing descent speed is set to 0 or very close to 0, there is a possibility that the aircraft will not be able to touch down if the positive error is large, so the landing descent speed is set to a certain speed within the range at which a safe landing is possible. The landing descent speed may be set according to the specifications of the aircraft. In addition, the transition altitude may be set to a rough guideline (for example, several times the diameter of the aircraft) according to the size of the aircraft. In that case, the altitude set as the transition altitude H may be applied. As an example, the transition descent speed v zH , time t tis adjusted appropriately to calculate the transition altitude H.

[0025] (Regarding horizontal ground speed) Next, the horizontal ground speed will be explained. If the mass of drone 1 is M and the acceleration due to gravity is g, the rotor thrust of drone 1 is (Mg+F v ) (See Figure 5). In addition, the horizontal component of the wind pressure, the horizontal force, is Receive TIFF0007754245000003.tif8163. TIFF0007754245000004.tif7163 is the horizontal ground speed vector of drone 1. TIFF0007754245000005.tif7163 is the horizontal wind vector. From the equation of motion, the horizontal ground velocity vector of drone 1 is TIFF0007754245000006.tif7163 is expressed by the following differential equation. TIFF0007754245000007.tif8163

[0026] The above equation is applied to the landing time t t When the horizontal ground speed is 0 If we solve it under the condition of TIFF0007754245000008.tif7163, the horizontal ground speed of drone 1 at transition point PA is TIFF0007754245000009.tif7163 can be obtained.

[0027] The above equation is TIFF0007754245000010.tif8163 must be clear, but it can be approximated by the following Equation 3.

[0028] [Formula 3] TIFF0007754245000011.tif8163

[0029] K1 and K2 are the linear and quadratic constants of the wind pressure acting on drone 1. K1 and K2 can be determined in advance through experiments, simulations, etc. If we take only the component of drone 1's speed that is parallel to the wind, we obtain the equation shown in Equation 4 below.

[0030] [Formula 4] TIFF0007754245000012.tif14163

[0031] By solving the above equation 4 numerically, or by approximating K2 = 0 and solving it analytically, the horizontal ground speed of drone 1 required at the transition point PA is obtained. TIFF0007754245000013.tif7163 can be obtained.

[0032] The horizontal ground speed is set by a control unit included in the drone according to each embodiment. Once the horizontal ground speed of the drone 1 is determined, the horizontal coordinate (x', y') of the transition point PA is determined by integrating the horizontal ground speed. Then, the coordinate (x', y', H) of the transition point PA is determined together with the transition altitude H determined as described above.

[0033] (Wind information estimation method) Next, a method for estimating wind information will be described. In this description, wind information is acquired by a drone 1 (multicopter) as an example.

[0034] As a method for estimating wind information, as shown in Fig. 6A, drone 1 is kept horizontal and the airspeed of drone 1 is set to 0. The ground speed of the drone at that time is TIFF0007754245000014.tif7163 is the wind vector Since this is equal to TIFF0007754245000015.tif7163, this value is set as the wind information.

[0035] Other methods for estimating wind information include the airspeed estimated from the drone's onboard speedometer or the aircraft's attitude. Aircraft ground speed from TIFF0007754245000016.tif7163 Wind vector by vector subtraction of TIFF0007754245000017.tif7163 TIFF0007754245000018.tif7163 is estimated (see Figure 6B). The estimation result is set as wind information.

[0036] If the uncertainty in the estimated ground speed is large, drone 1 flies a course that returns to the starting point atmospherically (see Figure 6C), and estimates the difference in airspeed between the starting point and the ending point or the wind direction and speed. This can cancel the uncertainty in the estimated airspeed.

[0037] In addition to the above-mentioned methods, wind information may be estimated based on changes in the position of the drone 1 using SLAM (Simultaneous Localization and Mapping), and the attitude and motor output of the drone 1. Wind information may also be estimated based on the difference between the GPS (Global Positioning System) position of the drone 1 and the attitude and motor output of the drone 1. Wind information may be estimated or measured by an external device, such as a ground station or another drone. The measured wind information may then be transmitted from the ground station to the drone 1 and acquired by a wind information acquisition unit. Wind information may also be input by a user via a UI (User Interface), and the input wind information may be transmitted to the drone 1.

[0038] First Embodiment [Example of the internal structure of a drone] 7 is a block diagram showing an example of the internal configuration of a drone according to the first embodiment (hereinafter referred to as drone 1A). Drone 1A has, for example, a control unit 101, an aircraft control unit 102, a sensor unit 103, an aircraft information acquisition unit 104, a wind information acquisition unit 105, and a communication unit 106. The control unit 101 has, as functional blocks, a flight status management unit 101A, a flight planner 101B, a landing planner 101C, and an attitude planner 101D.

[0039] The control unit 101 performs overall control of the drone 1A. The flight state management unit 101A performs overall management of the flight state of the drone 1A and switches between control by the flight planner 101B and control by the landing planner 101C depending on the flight state. The flight planner 101B generates a flight course plan for the drone 1A. The flight course plan is information that specifies the time-series positions where the drone 1A will fly and the speed at those positions. The flight course plan may be set in advance or may be generated by the flight planner 101B depending on the task assigned to the drone 1A. The flight planner 101B outputs the flight course plan to the attitude planner 101D.

[0040] The landing planner 101C generates an approach course plan and a touchdown course plan. The approach course plan is information that specifies the time-series positions from the current position of the drone 1A to the transition point PA and the speed at that position. Furthermore, the touchdown course plan in this embodiment is information that specifies the attitude from the transition point PA to the landing point LP, the time-series positions, and the vertical speed at that position. The landing planner 101C outputs the approach course plan and the touchdown course plan to the attitude planner 101D.

[0041] Attitude planner 101D generates aircraft control information according to the flight course plan provided by flight planner 101B and the approach course plan and touchdown course plan provided by landing planner 101C. Attitude planner 101D generates aircraft control information for drone 1A so that the drone will be at a position and at a speed at that position (specifically, vertical and horizontal ground speeds) specified in the flight course plan. Attitude planner 101D determines aircraft control information including attitude, vertical acceleration, etc., according to the flight course plan, taking into account deviations in the aircraft's position and speed, for example.

[0042] Furthermore, the attitude planner 101D generates aircraft control information for the drone 1A so that the drone 1A assumes a position and speed at that position (specifically, vertical and horizontal ground speeds) specified in the approach course plan. The attitude planner 101D also generates aircraft control information for the drone 1A so that the drone 1A assumes a position, vertical speed at that position, and attitude specified in the touchdown course plan. The attitude planner 101D outputs the aircraft control information to the aircraft control unit 102. Note that the attitude planner 101D generates aircraft control information for controlling the attitude of the drone 1A in accordance with the touchdown course plan so as to realize the attitude given by the touchdown course plan, without correcting the horizontal position or horizontal speed of the drone 1A's body, for example.

[0043] The aircraft control unit 102 performs control according to the aircraft control information supplied from the attitude planner 101 D. For example, the aircraft control unit 102 controls the rotation speed of the motor of the drone 1A so that the drone 1A assumes an attitude and speed according to the aircraft control information.

[0044] The sensor unit 103 is a collective term for a plurality of sensors that acquire aircraft information of the drone 1A (for example, the current position, speed, attitude, etc. of the drone 1A). Examples of sensors that make up the sensor unit 103 include a GPS, a SLAM, an acceleration sensor, a gyro sensor, and a barometric pressure sensor.

[0045] The machine information acquisition unit 104 appropriately converts the sensing data input from the sensor unit 103 from analog data to digital data. Then, the machine information acquisition unit 104 outputs the sensing data converted into digital data to the control unit 101.

[0046] The wind information acquisition unit 105 acquires wind information and outputs the acquired wind information to the control unit 101. A specific example of a method for estimating wind information has already been described, so a duplicated description will be omitted.

[0047] The communication unit 106 is used by the drone 1A to communicate with other devices. The communication unit 106 has a modulation / demodulation circuit and the like according to the communication method. The communication unit 106 communicates with, for example, the ground station GS. Through such communication, for example, wind information transmitted from the ground station GS is received by the communication unit 106. The communication unit 106 outputs the received wind information to the control unit 101.

[0048] [Processing flow] FIG. 8 is a flowchart showing the flow of processing performed by the drone 1A according to the first embodiment.

[0049] In step ST101, the flight status management unit 101A decides to land. As described above, the flight status management unit 101A decides to land in response to an instruction via remote control, completion of a given task, a decrease in the remaining battery capacity, a failure of a sensor possessed by the drone 1, the occurrence of a communication failure, etc. Although not shown in the figure, before step ST101, the drone 1A flies based on a flight course plan by the flight planner 101B. Then, the process proceeds to step ST102.

[0050] In step ST102, the flight state management unit 101A switches the planner from the flight planner 101B to the landing planner 101C. The flight state management unit 101A also provides the coordinates of the landing point LP to the landing planner 101C. Then, the process proceeds to step ST103.

[0051] In step ST103, the landing planner 101C acquires wind information. The wind information may be estimated by the drone 1A or transmitted from the ground station GS. The landing planner 101C then generates a touchdown course plan from the acquired wind information. Specifically, the landing planner 101C sets the horizontal ground speed of the drone 1A based on the acquired wind information, and determines the position of the transition point PA based on the horizontal ground speed. The specific method for setting the horizontal ground speed is as described above. The landing planner 101C also generates a touchdown course plan that includes the attitude at the transition point PA (horizontal in this example), the time-series positions from the transition point PA to the landing point LP, and the vertical acceleration at that position. Then, the process proceeds to step ST104.

[0052] In step ST104, the landing planner 101C generates an approach course plan from the current position to the transition point PA so that the position of the transition point PA and the speed of the drone 1A at the transition point PA become the horizontal ground speed determined in step ST103. Then, the processing proceeds to step ST105.

[0053] In step ST105, the landing planner 101C provides an approach course plan to the attitude planner 101D, and the process then proceeds to step ST106.

[0054] In step ST106, the attitude planner 101D generates aircraft control information based on the approach course plan up to the transition point PA. The aircraft control unit 102 operates based on the generated aircraft control information, causing the drone 1A to move to a position specified in the approach course plan. The aircraft control unit 102 also operates based on the generated aircraft control information, causing the motor of the drone 1A to rotate so as to achieve the speed specified in the approach course plan. Then, the process proceeds to step ST107.

[0055] In step ST107, it is determined that the aircraft altitude has reached the altitude of the transition point PA. For example, based on sensing data input from the sensor unit 103, the flight state management unit 101A determines that the aircraft altitude of the drone 1A has reached the altitude of the transition point PA. The flight state management unit 101A notifies the landing planner 101C that the aircraft altitude of the drone 1A has reached the altitude of the transition point PA. Upon receiving the notification, the landing planner 101C provides the touchdown course plan generated in step ST103 to the attitude planner 101D. Then, the processing proceeds to step ST108.

[0056] In step ST108, the attitude planner 101D generates aircraft control information based on the touchdown course plan. The touchdown course plan in this example includes information for keeping the attitude horizontal and information regarding vertical acceleration. Therefore, upon receiving the touchdown course plan, the attitude planner 101D generates aircraft control information for keeping the attitude of the drone 1A horizontal after passing the transition point PA, and aircraft control information including vertical speed. The attitude planner 101D then outputs the generated aircraft control information to the aircraft control unit 102. The aircraft control unit 102 operates based on the aircraft control information, causing the drone 1A to descend at a predetermined speed while maintaining the attitude of the drone 1A horizontal. Then, the process proceeds to step ST109.

[0057] In step ST109, once the landing planner 101C confirms that the drone 1A has landed, it instructs the attitude planner 101D to put the propellers of the drone 1A into an idle state. The attitude planner 101D generates aircraft control information based on this instruction. The attitude planner 101D outputs the generated aircraft control information to the aircraft control unit 102. The aircraft control unit 102 operates based on the aircraft control information, causing the propellers of the drone 1A to go into an idle state. The idle state refers to a state in which the propellers of the drone 1A rotate at a rotation speed below a predetermined value (a rotation speed at which the drone 1A does not rise). When the propellers of the drone 1A go into an idle state, the user can recognize that the drone 1A is not broken. Note that the propellers of the drone 1A may be stopped without going into an idle state.

[0058] According to the first embodiment described above, a horizontal ground speed is given to the drone 1A in advance at the transition point PA so that the horizontal ground speed at the time of landing is 0 or approximately 0. Furthermore, after the transition point PA, the attitude of the drone 1A is controlled to be horizontal. Therefore, the drone 1A can be landed stably.

[0059] <Second embodiment> Next, a second embodiment will be described. In the description of the second embodiment, the same or similar components as those in the above description will be denoted by the same reference numerals, and duplicated descriptions will be omitted as appropriate. Furthermore, unless otherwise specified, the matters described in the first embodiment can be applied to the second embodiment.

[0060] 9 is a block diagram showing an example of the configuration of a drone according to the second embodiment (hereinafter referred to as drone 1B). The drone 1B differs from the drone 1A in configuration in that the drone 1B does not have a wind information acquisition unit 105, and the control unit 101 has a wind measurement planner 101E.

[0061] The wind measurement planner 101E generates a course plan for acquiring wind information. The wind measurement planner 101E outputs the generated course plan to the attitude planner 101D. The attitude planner 101D generates aircraft control information for causing the drone 1B to move along the course plan supplied from the wind measurement planner 101E and for the speed of the drone 1B to be in accordance with the course plan. The attitude planner 101D outputs the generated aircraft control information to the aircraft control unit 102. The aircraft control unit 102 operates based on the aircraft control information, thereby realizing the course plan generated by the wind measurement planner 101E.

[0062] 10 is a flowchart showing the flow of processing performed by the drone 1B. In step ST101, the flight state management unit 101A determines landing, as in the first embodiment. Then, the processing proceeds to step ST201.

[0063] In step ST201, the flight state management unit 101A switches the planner from the flight planner 101B to the wind measurement planner 101E, and the process then proceeds to step ST202.

[0064] In step ST202, the wind measurement planner 101E measures the wind and generates a course plan for acquiring wind information. The course plan for acquiring wind information is, for example, information that specifies the time-series positions of the drone 1B, and the attitude and speed at those positions. Then, the process proceeds to step ST203.

[0065] In step ST203, the wind measurement planner 101E sends the course plan it has created to the attitude planner 101D, and the process then proceeds to step ST204.

[0066] In step ST204, the attitude planner 101D generates aircraft control information that realizes the course plan planned by the wind measurement planner 101E, specifically, the flight position and the attitude and speed at that flight position. Then, the attitude planner 101D sends the aircraft control information to the aircraft control unit 102. The aircraft control unit 102 operates based on the aircraft control information, causing the drone 1B to fly. Then, the process proceeds to step ST205.

[0067] In step ST205, the wind measurement planner 101E estimates wind information by applying a known method, for example, based on the deviation between the course plan for acquiring wind information and the actual position of the drone 1B.

[0068] Following the process of step ST205, the processes of steps ST102 to ST109 are performed. Note that the contents of the processes of steps ST102 to ST109 have already been explained, so a duplicate explanation will be omitted.

[0069] According to the second embodiment described above, the drone 1B can autonomously generate a course plan for acquiring wind information and acquire wind information according to the course plan.

[0070] <Third embodiment> Next, a third embodiment will be described. In the description of the third embodiment, the same or similar components as those in the above description will be denoted by the same reference numerals, and duplicated descriptions will be omitted as appropriate. Furthermore, unless otherwise specified, the matters described in the first and second embodiments can be applied to the second embodiment.

[0071] The drone according to the third embodiment (hereinafter referred to as drone 1C as appropriate) can have a configuration similar to that of drone 1A described in the first embodiment. In the first embodiment, the attitude (horizontal) after the transition point PA was given as the touchdown course plan, but the third embodiment differs from the first embodiment in that the horizontal ground speed from the transition point PA to the landing point LP is given as the touchdown course plan.

[0072] 11 is a flowchart showing the flow of processing performed by the drone 1C. The processing contents of steps ST101 to ST104 have already been explained, so duplicate explanations will be omitted where appropriate. In this embodiment, the touchdown course plan generated in step ST103 specifies the horizontal ground speed at the transition point PA and the horizontal ground speed at each position from the transition point PA to the landing point LP.

[0073] In step ST301 following step ST104, the landing planner 101C integrates the touchdown course plan and the approach course plan, and the process then proceeds to step ST301.

[0074] In step ST302, the landing planner 101C provides the integrated course plan to the attitude planner 101D, and the process then proceeds to step ST303.

[0075] In step ST303, the attitude planner 101D generates aircraft control information to realize the course plan given to it by the landing planner 101C. Then, the attitude planner 101D outputs the generated aircraft control information to the aircraft control unit 102. As the aircraft control unit 102 operates in accordance with the aircraft control information, the drone 1C assumes a position, an attitude at that position, and a horizontal ground speed in accordance with the course plan integrated by the landing planner 101C. Then, the process proceeds to step ST109. The contents of step ST109 have already been explained, so a duplicate explanation will be omitted.

[0076] As described above, according to the third embodiment, by giving the drone 1C a horizontal ground speed from the transition point PA to the landing point LP, the drone 1C can be landed in a stable attitude.

[0077] <Fourth embodiment> Next, a fourth embodiment will be described. In the description of the fourth embodiment, the same or similar components as those in the above description will be denoted by the same reference numerals, and duplicated descriptions will be omitted as appropriate. Furthermore, unless otherwise specified, the matters described in the first to third embodiments can be applied to the fourth embodiment.

[0078] 12 is a block diagram showing an example of the configuration of a drone according to the fourth embodiment (hereinafter referred to as drone 1D as appropriate). Drone 1D differs from drone 1A in that it includes a go-around planner 101F. Go-around planner 101F is a planner that aborts landing and causes drone 1D to ascend to a safe altitude if the attitude or horizontal ground speed of drone 1D at the time of landing is not within an allowable range.

[0079] 13 is a flowchart showing the flow of processing performed by the drone 1D. The processing of steps ST101 to ST104 and the processing of steps ST301 to ST303 have already been explained, so duplicate explanations will be omitted. Following the processing of step ST303, the processing proceeds to step ST401.

[0080] In step ST401, it is determined whether the drone 1D has passed the transition point PA, specifically, whether the altitude of the drone 1D has become equal to or lower than the transition point PA. This determination is made by the flight status management unit 101A, for example, based on sensing data acquired by the sensor unit 103. If the drone 1D has not passed the transition point PA, the process returns to step ST303. If the drone 1D has passed the transition point PA, the process proceeds to step ST402.

[0081] In step ST402, it is determined whether the drone 1D has landed on the ground. This determination is made by the flight state management unit 101A, for example, based on sensing data acquired by the sensor unit 103. If the flight state management unit 101A determines that the drone 1D has landed on the ground, the process proceeds to step ST403.

[0082] In step ST403, the flight status management unit 101A notifies the landing planner 101C that the drone 1D has touched down. Upon receiving the notification, the landing planner 101C instructs the attitude planner 101D to put the propellers of the drone 1A into an idle state. The attitude planner 101D generates aircraft control information based on this instruction. The attitude planner 101D outputs the generated aircraft control information to the aircraft control unit 102. The aircraft control unit 102 operates based on the aircraft control information, causing the propellers of the drone 1A to enter an idle state. As described above, the idle state refers to a state in which the propellers of the drone 1A rotate at a rotation speed equal to or lower than a predetermined speed (a rotation speed at which the drone 1A does not rise).

[0083] If it is determined in the determination process of step ST402 that the drone 1D is not on the ground, the process proceeds to step ST404.

[0084] In step ST404, it is determined whether the inclination of the drone 1D's body and the horizontal ground speed are within the allowable range. This determination is made by the flight state management unit 101A, for example, based on sensing data acquired by the sensor unit 103. Specifically, the flight state management unit 101A determines whether the inclination of the drone 1D is equal to or less than a threshold, and if the inclination of the drone 1D is equal to or less than the threshold, determines that the inclination of the drone 1D is within the allowable range. The flight state management unit 101A also determines whether the difference between the current horizontal ground speed and the horizontal ground speed specified in the course plan is equal to or less than a threshold, and if the difference is equal to or less than the threshold, determines that the current horizontal ground speed is within the allowable range.

[0085] If it is determined that the inclination or horizontal ground speed of the drone 1D is within the allowable range, the process returns to step ST303. If it is determined that the inclination or horizontal ground speed of the drone 1D is not within the allowable range, the process proceeds to step ST405.

[0086] In step ST405, the flight status management unit 101A switches the planner from the landing planner 101C to the go-around planner 101F. The go-around planner 101F performs control to abort the landing because the inclination of the drone 1D's body and the horizontal ground speed are not within the allowable range. Specifically, the go-around planner 101F generates a course plan for ascending the drone 1D to a safe altitude. The go-around planner 101F outputs the generated course plan to the attitude planner 101D. Then, the processing proceeds to step ST406.

[0087] In step ST406, the attitude planner 101D generates aircraft control information for realizing the course plan provided by the go-around planner 101F. Then, the attitude planner 101D outputs the generated aircraft control information to the aircraft control unit 102. The aircraft control unit 102 controls the motor rotation speed and the like in accordance with the aircraft control information, causing the drone 1D to ascend to a safe altitude. Then, the process proceeds to step ST407.

[0088] In step ST407, the drone 1D, which has ascended to a safe altitude, enters a standby state. The flight status management unit 101A of the drone 1D, for example, performs control to resume the landing sequence for landing the drone 1D again (for example, the processing of steps ST101 to ST104 and steps ST301 and ST302 described above). The drone 1D may wait for instructions from the user.

[0089] In this embodiment, it is determined whether the inclination of the drone 1D's body and horizontal ground speed are within the allowable range, but it is also possible to determine whether either one of them is within the allowable range, or whether other parameters are within the allowable range.

[0090] According to the fourth embodiment described above, the drone 1D can be raised to a safe altitude when the inclination of the airframe or the horizontal ground speed differs from the plan. Therefore, it is possible to prevent the drone 1D from failing to land due to the drone 1D performing a landing operation in an inappropriate attitude, etc.

[0091] <Modification> Although the embodiments of the present disclosure have been specifically described above, the content of the present disclosure is not limited to the above-described embodiments, and various modifications based on the technical ideas of the present disclosure are possible. Modifications will be described below.

[0092] In the above-described embodiments, for convenience of explanation, the control unit has been described as having a plurality of planners, but the present invention is not limited to this. For example, the flight planner and the landing planner may be configured as a single functional block.

[0093] A known method for controlling drones can be applied to the drones in each of the above-described embodiments.

[0094] The present disclosure can also be realized by an apparatus, a method, a program, a system, etc. For example, a program that performs the functions described in the above-described embodiments can be made downloadable, and an apparatus that does not have the functions described in the embodiments can download and install the program, thereby enabling the apparatus to perform the control described in the embodiments. The present disclosure can also be realized by a server that distributes such a program. The present disclosure can also be realized as a tool that easily creates the flight plan described in the embodiments. Furthermore, the matters described in each embodiment and modified example can be combined as appropriate.

[0095] The effects described in this specification are not necessarily limited to those described herein, and may be any effect described in this disclosure. Furthermore, the contents of this disclosure should not be interpreted as being limited by the exemplified effects.

[0096] The present disclosure may also have the following configurations. (1) A plurality of motors; a control unit that controls the rotation speed of the plurality of motors, The control unit sets a horizontal ground speed at a point where a landing operation starts based on wind information including information about wind direction and wind speed, and performs control to reduce a descent speed from the point where the landing operation starts to the landing point. Flying vehicle. (2) The wind information includes information about wind that affects the flight of the aircraft. (1) The aircraft described in (1). (3) The horizontal ground speed set by the control unit becomes approximately 0 at the landing point. An aircraft described in (1) or (2). (4) The control unit controls the attitude so that the attitude is approximately horizontal at a point located above the landing point. An aircraft described in any one of (1) to (3). (5) The control unit controls the aircraft to ascend when at least one of the inclination and the horizontal ground speed of the aircraft exceeds an allowable range between the start of the landing operation and the landing point. An aircraft described in any one of (1) to (4). (6) The altitude of the point at which the landing operation begins is determined based on at least the horizontal ground speed. (5) The aircraft described in (5). (7) a wind information acquisition unit for acquiring the wind information An aircraft described in any one of (1) to (6). (8) The flying object includes a sensor unit, The wind information acquisition unit calculates and acquires the wind information based on a difference between the sensing data acquired by the sensor unit and the motor output. (7) The aircraft described in (7). (9) The wind information acquisition unit acquires the wind information from an external device. (7) The aircraft described in (7). (10) The control unit controls the descent speed of the aircraft to decrease at a constant rate from the point at which the landing operation starts to the landing point. An aircraft described in any one of (1) to (9). (11) A control unit controls the rotation speed of the multiple motors, The control unit sets a horizontal ground speed at a point where a landing operation starts based on wind information including information about wind direction and wind speed, and performs control to reduce a descent speed from the point where the landing operation starts to the landing point. A method for controlling an aircraft. (12) A control unit controls the rotation speed of the multiple motors, The control unit sets a horizontal ground speed at a point where a landing operation starts based on wind information including information about wind direction and wind speed, and performs control to reduce a descent speed from the point where the landing operation starts to the landing point. A program that causes a computer to execute a method for controlling an aircraft. [Explanation of symbols]

[0097] 1A to 1D: Drone; 101: Control unit; 101A: Flight status management unit; 101B: Flight planner, landing planner; 101C: Attitude planner; 101D: Aircraft control unit; 103: Sensor unit; 105: Wind information acquisition unit; 106: Communication unit

Claims

1. A plurality of motors; a control unit that controls the rotation speed of the plurality of motors, The control unit acquires wind information including information on wind direction and wind speed, sets the horizontal ground speed at the point where the landing operation is started so that the horizontal ground speed at the landing point becomes 0 when the descent speed is reduced at a constant rate from the point where the landing operation is started to the landing point under the conditions of the wind information, and performs control to reduce the descent speed at a constant rate from the point where the landing operation is started to the landing point. Flying vehicle.

2. The altitude of the point at which the landing operation starts is set based on the descent speed which decreases at a constant rate, and the horizontal position of the point at which the landing operation starts is set based on the horizontal ground speed. The flying vehicle according to claim 1 .

3. The wind information includes information about wind that affects the flight of the aircraft. The flying vehicle according to claim 1 .

4. The control unit controls the attitude at the point where the landing operation starts so that the attitude is approximately horizontal. The flying vehicle according to claim 1 .

5. The control unit controls the aircraft to ascend when at least one of the inclination and the horizontal ground speed of the aircraft exceeds an allowable range between the start of the landing operation and the landing point. The flying vehicle according to claim 1 .

6. a wind information acquisition unit for acquiring the wind information; The flying vehicle according to claim 1 .

7. The flying object includes a sensor unit, The wind information acquisition unit calculates and acquires the wind information based on a difference between the sensing data acquired by the sensor unit and the motor output. The flying vehicle according to claim 6.

8. The wind information acquisition unit acquires the wind information from an external device. The flying vehicle according to claim 6.

9. A control unit controls the rotation speed of the multiple motors, The control unit acquires wind information including information on wind direction and wind speed, sets the horizontal ground speed at the point where the landing operation is started so that the horizontal ground speed at the landing point becomes 0 when the descent speed is reduced at a constant rate from the point where the landing operation is started to the landing point under the conditions of the wind information, and performs control to reduce the descent speed at a constant rate from the point where the landing operation is started to the landing point. A method for controlling an aircraft.

10. A control unit controls the rotation speed of the multiple motors, The control unit acquires wind information including information on wind direction and wind speed, sets the horizontal ground speed at the point where the landing operation is started so that the horizontal ground speed at the landing point becomes 0 when the descent speed is reduced at a constant rate from the point where the landing operation is started to the landing point under the conditions of the wind information, and performs control to reduce the descent speed at a constant rate from the point where the landing operation is started to the landing point. A program that causes a computer to execute a method for controlling an aircraft.

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