JP4925862B2 - Computers and unmanned aerial vehicles - Google Patents

Description

  The present invention relates to an automatic landing method for landing an unmanned aerial vehicle (hereinafter also referred to as an unmanned aerial vehicle) that performs autonomous flight in a narrow landing range.

Many drones, particularly small drones, have an avionics board equipped with GPS (Global Positioning System) and MEMS (Micro Electro Mechanical System) sensors, and perform autonomous flight.
A major problem in the operation of drones is the landing method.
Small and light drones are assumed to be used in places without equipment such as dedicated runways, and there may be restrictions such as obstacles, but the choice of takeoff and landing directions is highly flexible.
If there is a wide landing space with no obstacles around, it is possible to land by descending linearly from high altitude toward the target point, but landing in narrow places, especially when there are obstacles around For example, manual landing is often performed by switching to manual control. Manual maneuvering requires experience and is a problem in facilitating operation.

In addition, a technique for automatically guiding and landing a drone to a target runway instead of manual operation has been considered.
As a conventional automatic landing method for unmanned aerial vehicles, multiple information on air speed, ground speed, and azimuth is acquired during flight, statistical processing is performed to estimate wind speed and direction, and automatic approach from the downwind direction of the runway A wind speed estimation method for performing is known (for example, Patent Document 1).
JP 2005-219699 A

However, since the wind estimation of Patent Document 1 requires statistical processing, it is necessary to further reduce the calculation load, particularly in a small unmanned aircraft in which the installed computer is small and the calculation load needs to be reduced.
In addition, since the wind direction may remain different between the sky and near the ground, if the wind direction changes at the time of landing, it is necessary to stop landing for safety and start again. Does not support canceling and redoing.

The main object of the present invention is to solve the above-mentioned problems, and to realize a technology for automatically landing an unmanned aircraft at a target landing point while periodically estimating wind. .
Specifically, the main purpose is to realize a technology for automatically landing an unmanned aerial vehicle at a target landing point with the shortest approach distance in the weather condition during landing operation.

The computer according to the present invention is:
A computer mounted on an unmanned aerial vehicle equipped with an airspeed detecting means for detecting an airspeed, a ground speed detecting means for detecting a ground speed, and a speed direction detecting means for detecting a speed direction,
A wind speed for estimating a wind speed and a wind direction based on the air speed detected by the air speed detection means, the ground speed detected by the ground speed detection means, and the speed direction detected by the speed direction detection means. A wind direction estimation unit;
A storage unit for storing a landing approach start altitude at which the unmanned aircraft starts descent to a landing target point;
In accordance with the estimated wind speed estimated by the wind speed and wind direction estimating unit, the landing approach distance from the landing approach starting point to the landing target point where the unmanned aircraft starts to descend to the landing target point is determined, and the determined landing approach distance And a landing approach start point determination unit that determines a landing approach start point based on the estimated wind direction estimated by the wind speed and wind direction estimation unit and the landing approach start altitude stored in the storage unit, To do.

  According to the present invention, the wind speed and the wind direction during the landing operation are estimated, and the drone is automatically landed at the target landing point with the shortest approach distance suitable for the weather condition during the landing operation based on the estimated wind speed and the wind direction. Can do.

Embodiment 1 FIG.
The landing method according to the present embodiment can be applied to any unmanned aerial vehicle, but here, it is highly effective and does not require a special operation facility, and can be landed in an arbitrary direction and has a weight of about 2 kg. The procedure until landing is explained in detail.

  Hereinafter, an automatic landing method for an unmanned aerial vehicle, a computer, and an unmanned aircraft according to the first embodiment will be described with reference to the drawings.

FIG. 1 shows an example of arrangement of internal devices of an unmanned aerial vehicle 1 that performs autonomous flight.
For example, the unmanned aerial vehicle 1 includes a Pitot tube 4 outside the fuselage and is connected to an internal pressure gauge 5 to obtain airspeed from dynamic pressure during flight.
On the other hand, the unmanned aerial vehicle 1 is installed with a GPS antenna 2 and connected to a GPS receiver 3 to obtain ground speed and speed direction (azimuth angle) during flight.
In addition, sensors necessary for autonomous flight, such as an accelerometer, are arranged inside the body of the unmanned aerial vehicle 1, but the details are omitted because they are not directly related to the contents of the present embodiment.
These sensors are connected to a computer 6 disposed inside the unmanned aerial vehicle 1, and the computer 6 is controlled by an internal calculation to control a rudder 7, for example, an ordinary wing, an auxiliary wing, an elevator, a rudder, and a thrust. By controlling, autonomous flight such as flying toward the target point is realized.

FIG. 2 shows a configuration example of the computer 6 mounted on the unmanned aerial vehicle 1.
The computer 6 is connected to an airspeed detection means 11, a ground speed detection means 12, and a speed direction detection means 13 that are mounted on the unmanned aircraft 1.
The airspeed detection means 11 is a means for detecting the airspeed of the unmanned aircraft 1, and corresponds to the Pitot tube 4 and the pressure gauge 5 shown in FIG. The ground speed detection means 12 is a means for detecting the ground speed of the unmanned aircraft 1, and corresponds to the GPS antenna 2 and the GPS receiver 3 shown in FIG. The speed direction detection means 13 is a means for detecting the speed direction of the unmanned aircraft 1, and corresponds to the GPS antenna 2 and the GPS receiver 3 shown in FIG.

In the computer 6, the speed information input unit 61 detects the airspeed information detected by the airspeed detection means 11, the information on the groundspeed detected by the groundspeed detection means 12, and the speed direction detection means 13 detects. Information on the speed direction is input from the air speed detection means 11, the ground speed detection means 12, and the speed direction detection means 13, respectively.
Note that airspeed information, ground speed information, and speed direction information are collectively referred to as speed information.

The wind speed / wind direction estimation unit 62 is based on the air speed detected by the air speed detection unit 11, the ground speed detected by the ground speed detection unit 12, and the speed direction detected by the speed direction detection unit 13. Estimate wind speed and direction.
More specifically, as will be described later, the wind speed / wind direction estimation unit 62 determines the air speed, the ground speed, and the speed direction detected when the unmanned aircraft 1 is turning above the landing target point. Based on this, the wind speed and direction when the unmanned aircraft 1 descends to the landing target point are estimated.
In addition, the wind speed / wind direction estimation unit 62 moves to the landing target point of the unmanned aircraft 1 based on the air speed, the ground speed, and the speed direction detected when the unmanned aircraft 1 is turning at the landing approach start altitude. The wind speed and direction at the time of descent may be estimated.
Further, the wind speed / wind direction estimating unit 62 lands the unmanned aircraft 1 based on the air speed, the ground speed, and the speed direction detected when the unmanned aircraft 1 is turning at the cruise altitude above the landing target point. Estimate the wind speed and direction at the time of descent to the target point, make this wind speed and direction the first estimated wind speed and the first estimated wind direction, and turn at the landing approach start altitude after the unmanned aircraft 1 descends to the landing approach start altitude The wind speed and the wind direction when the unmanned aircraft 1 descends to the landing target point are estimated based on the air speed, the ground speed, and the speed direction detected while It may be the wind speed and the second estimated wind direction.

The storage unit 63 stores the airspeed during descent, the descent speed, the landing approach start altitude, and the landing target point.
The airspeed when descending is the airspeed when the unmanned aerial vehicle 1 descends to the landing target point.
The descending speed is a speed at which the unmanned aircraft 1 descends to the landing target point.
The landing approach start altitude is an altitude at which the unmanned aircraft 1 starts to descend to the landing target point.
The landing target point is a point that the unmanned aircraft 1 is a landing target.
The airspeed at the time of descent, the descent speed, the landing approach start altitude, and the landing target point information may be stored in the storage unit 63 before the flight of the unmanned aerial vehicle 1, or may be stored from the ground communication station during the flight. Such information may be transmitted, received by the communication function of the unmanned aircraft 1 (not shown), and written in the storage unit 63.
In any case, when the calculator 6 calculates the landing approach start point, the airspeed at the time of descent, the descent speed, the landing approach start altitude, and the landing target point information exist in the storage unit 63. Shall.

The landing approach start point determination unit 64 landes the unmanned aircraft based on the estimated wind speed by the wind speed / wind direction estimation unit 62, the airspeed at the time of descent stored in the storage unit 63, the landing approach start altitude, and the descent rate. The landing approach distance from the landing approach starting point to start the descent to the target point to the landing target point is determined, and the determined landing approach distance, the estimated wind direction estimated by the wind speed / wind direction estimating unit 62, and stored in the storage unit 63 The landing approach start point is determined based on the landing approach start altitude.
As described above, the landing approach distance is determined based on the estimated wind speed, airspeed at descent, altitude at the start of landing approach, and descent speed, but the airspeed at descent, landing approach start altitude, and descent speed are fixed. Since it is a value (predetermined), the landing approach distance becomes longer or shorter depending on the wind speed estimated by the wind speed / wind direction estimating unit 62.
The landing approach start point determining unit 64 determines the first estimated wind speed, the first estimated wind direction, the second estimated wind speed, and the second estimated wind direction when the wind speed / wind direction estimating unit 62 obtains the first estimated wind speed. The landing approach start point is determined using the estimated wind speed and the first estimated wind direction, and between the first estimated wind speed and the second estimated wind speed, and between the first estimated wind direction and the second estimated wind direction. When the difference is less than a predetermined threshold value, a new landing approach start point is determined using the second estimated wind speed and the second estimated wind direction, and the difference is equal to or greater than the threshold value. If so, decide to cancel the landing sequence.

The navigation control unit 65 controls the control rudder 7 (auxiliary wing, elevator, rudder, etc.) and thrust, and performs control for autonomous flight of the drone 1. The navigation control unit 65 performs navigation control during cruising and navigation control during landing.
The navigation control unit 65 can be realized by existing technology.

FIG. 3 is a sequence at the time of landing according to the present embodiment.
FIG. 4 shows the altitude change of the drone 1 in each phase shown in FIG.
FIG. 5 is a flight trajectory in the horizontal plane of the drone 1 in each phase shown in FIG. 3.
S1 to S5 shown in FIGS. 4 and 5 correspond to the respective phases (S1 to S5) of FIG.
FIG. 6 is a flowchart showing a processing example of the computer 6.

Here, before describing each phase in detail with reference to FIGS. 3 to 6, an outline of an automatic landing method by the unmanned aircraft 1 and the computer 6 according to the present embodiment will be described.
As described above, the drone 1 measures the airspeed with a Pitot tube, and measures the ground speed and speed direction with GPS. A round flight with a constant turning radius is performed over the landing target point (cruising altitude) (turning on the right circle in FIG. 5), and the air speed, ground speed, and speed direction are measured. The direction in which the difference between the air speed and the ground speed measured in the orbital flight is the maximum is the windward direction, and the direction in which the difference is the minimum can be estimated as the leeward direction. For this reason, the wind speed / wind direction estimation unit 62 of the computer 6 estimates the wind direction and wind speed in the vicinity from the windward and leeward directions and the speed difference.
Since the aircraft's descent capability (descent speed, airspeed at descent) is known, and the landing approach start altitude is also specified, the distance required for the final approach (landing) along with the estimated wind speed and direction information The approach distance is determined.
In order to shorten the final approach, the landing approach start point is determined so that the approach from the leeward to the windward is performed when there is no restriction on the approach direction. The landing approach start point determination unit 64 of the computer 6 determines the landing approach start point based on these three elements of the landing approach start altitude, the landing approach distance, and the approach from the leeward side.
Next, the drone 1 lowers the altitude while drawing a circular orbit in contact with the final approach line (turns on the circle on the left side of FIG. 5), makes a cruise turn with a constant altitude again at the landing approach altitude, and starts landing approach When you reach the point, move to the final approach sequence and land.

Next, each phase will be described in detail with reference to FIGS.
In the CIRCLE phase (S1), a round flight with a constant turning radius is performed around the landing target point. At least one round is performed, and the air speed detection means 11, the ground speed detection means 12, and the speed direction detection means 13 measure the air speed, the ground speed, and the speed direction.
In the computer 6, the speed information input unit 61 inputs speed information from these detection means (S601 in FIG. 6). Next, the wind speed / wind direction estimation unit 62 estimates the wind speed and the wind direction when descending to the landing target point of the unmanned aircraft 1 from the speed information (S602 in FIG. 6). Specifically, the wind speed / wind direction estimation unit 62 extracts the value at which the difference obtained by subtracting the ground speed from the air speed is the maximum and minimum, and the speed direction (azimuth angle) at the two points, and the speed difference is the maximum. Is estimated as the windward direction, and the speed direction with the smallest speed difference is estimated as the leeward direction. The maximum speed difference is estimated as the wind speed from the windward to the leeward.
At this time, if the wind speed in the vicinity is constant, the speed difference between these two points becomes the value of the opposite sign having the same absolute value, and the phase difference between the directions becomes 180 degrees. However, the actual wind speed is not completely constant, and the sensor has measurement errors. For this reason, a threshold value is set for the speed difference and the phase difference, and when the absolute value difference and phase difference of the two speed differences are within the threshold range, the average value of the absolute value of the speed difference is defined as the wind speed. The wind direction is shifted by 180 degrees and averaged with the windward side to obtain the wind direction. In this way, the wind speed and wind direction estimation unit 62 can estimate the wind speed and the wind direction. After this estimation is completed, the process proceeds to the PRE_ENTRY phase.
In the CIRCLE phase, when the vehicle circulates two or more times, the wind speed and the wind direction are estimated from the average values of the air speed, the ground speed, and the speed direction measured in each circuit.

In the PRE_ENTRY phase (S2), a landing approach start point is determined from the estimated wind speed, wind direction, landing target point designated in advance, landing approach start altitude, and the like.
The landing approach start point determination unit 64 of the computer 6 first determines a horizontal distance (landing approach distance) from the landing target point to the landing approach start point (S603 in FIG. 6). Specifically, the landing approach start point determination unit 64 determines the landing approach distance using the following equation.
(Landing approach distance) = ((Airspeed at descent)-(Estimated wind speed)) * (Landing approach start altitude) / (Descent speed)
In the above equation, (landing approach start altitude) / (descent speed) indicates the time required to descend from the landing approach start altitude, and ((air speed during descent)-(estimated wind speed)) is the drone 1 Shows the horizontal speed. The estimated wind speed is the wind speed estimated by the wind speed / wind direction estimating unit 62.
As described above, as the normal descent capability of the drone 1, the airspeed during descent and the descent speed are known, the landing approach start altitude is also known, and is stored in the storage unit 63 of the computer 6. For this reason, the landing approach distance is determined according to the value of the estimated wind speed.
Next, the landing approach start point determination unit 64 starts the landing approach based on the determined landing approach distance, the estimated wind direction estimated by the wind speed / wind direction estimation unit 62, and the landing approach start altitude stored in the storage unit 63. A point is determined (S604 in FIG. 6).
Specifically, the landing approach start point determination unit 64 is at the landing approach start altitude, is separated from the landing target point by the landing approach distance in the horizontal direction, and is set as the landing target point in order to shorten the final approach. On the other hand, the point located at the windward position estimated as the landing approach start point is set.
Next, the landing approach start point determination unit 64 sets a circular orbit having the same turning radius as that of the CIRCLE phase in contact with the landing approach start point and the landing approach line connecting the landing approach start point and the landing target point (see FIG. 6 (S605)), the drone 1 enters the orbit, and then proceeds to the DOWN_REG phase.

In the DOWN_REG phase (S3), the drone 1 descends to the landing approach start altitude while circling the circular orbit set in the PRE_ENTRY phase. After descending to the landing approach start altitude, it shifts to the BASE_REG phase.
Here, also in the DOWN_REG phase, the wind speed and wind direction can be estimated in the same manner as in the CIRCLE phase, and the wind speed and wind direction estimation unit 62 estimates the wind speed and the wind direction in the same procedure as in S601 and S602 (S607 in FIG. 6). ). The air speed, ground speed, and speed direction, which are the standard for estimating the wind speed and wind direction in the DOWN_REG phase, are those detected when the unmanned aircraft 1 is turning at the landing approach start altitude after descending to the landing approach start altitude. Speed, ground speed, and speed direction. On the other hand, the air speed, the ground speed, and the speed direction, which are the reference for estimating the wind speed and wind direction in the CIRCLE phase, are the air speed detected when the unmanned aircraft 1 is turning at the cruise altitude above the landing target point, Ground speed and speed direction.
The wind speed and wind direction estimated in the CIRCLE phase are set as the first estimated wind speed and the first estimated wind direction, respectively. The wind speed and wind direction estimated in the DOWN_REG phase are set as the second estimated wind speed and the second estimated wind direction, respectively.
Then, the landing approach start point determination unit 64 compares the first estimated wind speed with the second estimated wind speed, and also compares the first estimated wind direction with the second estimated wind direction (S608 in FIG. 6).
The landing approach start point determination unit 64 has a threshold for the difference in the estimated value of the wind speed, and also has a threshold for the difference in the estimated value of the wind direction.
As a result of the comparison, if at least one of the difference in the estimated value of the wind speed and the difference in the estimated value of the wind direction is equal to or greater than the threshold (No in S609), the landing approach start point determination unit 64 determines to cancel the landing sequence. (S613), and shifts to the RECOVER phase (S614).
On the other hand, when the difference between the estimated value of the wind speed and the difference between the estimated values of the wind direction are both less than the threshold (Yes in S609), the landing approach start point determination unit 64 corrects the landing approach start point set in the PRE_ENTRY phase. It is determined whether or not (S610). For example, the landing approach start point determination unit 64 has a threshold value (a value smaller than the threshold value used in the determination in S609) for each of the difference in the estimated wind speed value and the difference in the estimated wind direction value. If the difference between the estimated value of wind and the estimated value of wind direction are both less than the threshold value, it is determined that the landing approach start point need not be corrected, and at least one of the difference between the estimated value of wind speed and the estimated value of wind direction When one is above the threshold, it is determined that the landing approach start point needs to be corrected.
If correction of the landing approach start point is unnecessary (No in S610), the process proceeds to S612.
If the landing approach start point needs to be corrected (Yes in S610), the landing approach start point determination unit 64 performs the processing of S603 to S605 with the second estimated wind speed and the second estimated wind direction, and creates a new one. After determining the landing approach start point and setting the turning trajectory based on the new landing approach start point (S611), the processing is shifted after the BASE_REG phase (S612).

  The landings determined based on the first estimated wind direction and the first estimated wind direction in the PRE_ENTRY phase without obtaining the second estimated wind speed and the second estimated wind direction without omitting the processes of S607 to S611 in the DOWN_REG phase. You may make it maintain an approach start point as it is. In this case, in the DOWN_REG phase, the vehicle descends to the landing approach start altitude while circling the circular orbit set in the PRE_ENTRY phase. After descending to the landing approach start altitude, it shifts to the BASE_REG phase.

  In the BASE_REG phase (S4), the wireless device 1 performs a turning flight again at the landing approach start altitude, maintains the landing approach start altitude and reaches the landing approach start point, and then proceeds to FINAL_REG.

In the FINAL_REG phase (S5), the landing is completed by descending toward the landing target point.
For example, when the designated point deviates more than a specified distance during the FINAL_REG, the process shifts to the RECOVER phase and stops the landing sequence.

In the RECOVER phase (S6), for example, processing is performed such as switching to the ascending mode, rising to the cruise altitude, and re-landing from the CIRCLE phase.
In addition to the above-described conditions, if it is difficult to continue landing safely, it may be considered to shift to the RECOVER phase and interrupt the landing.

As described above, according to the present embodiment, the wind speed and the wind direction during the landing operation are estimated, and based on the estimated wind speed and the wind direction, the drone is targeted for landing with the shortest approach distance suitable for the weather condition during the landing operation. Can be automatically landed on the spot.
Also, when the drone is flying at the landing approach start altitude, the wind speed and direction are estimated again, and if there is a difference of more than a certain value between the wind speed and wind direction estimated at the cruise altitude flight, The landing sequence can be canceled.
Even if there is no difference between the wind speed and direction, the landing approach start point can be re-determined according to the situation, so the wind condition differs between the cruise altitude and the landing approach start altitude. However, it is possible to automatically land the drone safely at the target landing point with the shortest approach distance that matches the weather conditions during landing operation.

As described above, in the present embodiment, an autonomous flight control including a sensor for measuring airspeed, a sensor for measuring ground speed, and a sensor that performs other internal calculation processing with the sensor to realize other autonomous flight. In unmanned aerial vehicles equipped with equipment and performing autonomous flight,
Airspeed and ground speed are measured while performing a turning flight with a constant turning radius over the landing target point, and the wind direction and wind speed are estimated by the internal processing computer from the measurement results, and the final landing approach point toward the landing point is determined. The automatic landing method was set up on the leeward side and automatically landed at the target landing point with the shortest approach distance in the weather conditions at that time.

  In this embodiment, when shifting from a cruise state to landing, a straight line that passes through the landing target point and faces the final approach path direction and a circular orbit that touches at the final approach start point is set, and the circular orbit is drawn. He explained the automatic landing method that descends, cruises again at the final approach altitude, and makes the final landing approach when the final approach start point in the circular orbit is reached.

Embodiment 2. FIG.
Hereinafter, an automatic landing method for an unmanned aerial vehicle, a computer, and an unmanned aircraft according to the second embodiment will be described with reference to the drawings.

FIG. 7 shows a route in the horizontal plane of the automatic landing of the drone 1 when there are obstacles around.
The operation of the drone 1 according to the present embodiment is outlined. When there are obstacles such as trees and buildings (prohibition area) around the landing area, the direction in which landing can be entered is input to the computer in the aircraft. The direction closest to the windward within the range is determined as the approach direction.
Here, the turning direction is automatically determined so that the circular orbit for lowering the altitude falls within the allowable range.

In the present embodiment, for example, when an obstacle such as a tree or a building exists around the landing target point, in the computer 6 of the unmanned aerial vehicle 1, the storage unit 63 is unmanned in addition to the information shown in FIG. The position information of the accessible range in which the aircraft 1 can enter is stored. The position information stored in the storage unit 63 specifies the start point direction and the end point direction of the landing approachable range, for example, with an azimuth angle based on the landing target point. Further, the landing approachable range may be held as information on latitude and longitude.
Further, in the present embodiment, the landing approach start point determination unit 64 causes the landing descending trajectory to the landing target point to be within the enterable range based on the position information of the enterable range stored in the storage unit 63. Determine the landing approach starting point.
Further, in the present embodiment, the landing approach start point determination unit 64 determines the turning trajectory of the turn performed before the unmanned aircraft 1 descends from the landing approach start point within the allowable range.
Note that the configuration of the unmanned aerial vehicle 1 and the configuration of the computer 6 according to the present embodiment are the same as those shown in FIGS. 1 and 2.
Moreover, the operation | movement at the time of landing of the unmanned aerial vehicle 1 is the same as that of the operation example shown in FIG.3 and FIG.6 except the point described below.

In the present embodiment, in the PRE_ENTRY phase (S2), the landing approach start point determination unit 64 is closest to the leeward direction within the landing approachable range when the set landing approach start point is outside the landing approachable range. The landing approach start point is set with the direction as the approach direction.
At this time, the rotation direction of the circular orbit for descent can be selected to be either a right turn or a left turn, but the landing approach start point determination unit 64 makes the track within the landing approachable range. Set.
Thereby, the direction which can land at the shortest distance within the approachable range can be selected.

  When landing on a specific runway, by limiting the possible landing approach range to two directions in the longitudinal direction of the runway, landing approach can be performed from the leeward side at that time, and landing on the runway can also be realized.

  As described above, according to the present embodiment, even when there are obstacles around the landing target point, the shortest approach line suitable for the weather condition at the time of landing operation among the approach lines that can avoid the obstacle is unmanned. The aircraft can land automatically at the target landing point.

  As described above, in the present embodiment, when there is an obstacle around the landing point, the landing approach direction is input to the internal processing computer in advance, so that the landing approach direction becomes the direction closest to the leeward within the approachable range. The automatic landing method that can land from a safe direction without an obstacle by setting and setting the turning direction of the circular orbit during landing operation so as not to come out of the accessible range was explained.

Embodiment 3 FIG.
Hereinafter, an automatic landing method for an unmanned aerial vehicle, a computer, and an unmanned aircraft according to the third embodiment will be described with reference to the drawings.

For example, as shown in FIG. 8, when landing with a parachute, the descent speed when the parachute is opened is recorded in the internal processing computer 6 as known information so that the altitude from the parachute opening to the landing can be recorded. The movement distance in the horizontal plane due to time and wind can be calculated.
In other words, in the present embodiment, the computer 6 is mounted on the unmanned aerial vehicle 1 that opens the parachute from a predetermined altitude when landing and descends, and the storage unit 63 stores the information shown in FIG. In addition, the parachute opening altitude at which the unmanned aerial vehicle 1 opens the parachute and the descending speed when the parachute is opened are stored.
In the present embodiment, the landing approach start point determination unit 64 includes the estimated wind speed estimated by the wind speed / wind direction estimation unit 62, the airspeed during descent stored in the storage unit 63, and the landing approach start altitude. The landing approach distance is determined based on the descending speed, the parachute opening height, and the parachute opening speed, and the landing approach starting point is determined.
Note that the configuration of the unmanned aerial vehicle 1 and the configuration of the computer 6 according to the present embodiment are the same as those shown in FIGS. 1 and 2.
Moreover, the operation | movement at the time of landing of the unmanned aerial vehicle 1 is the same as that of the operation example shown in FIG.3 and FIG.6 except the point described below.

  In the present embodiment, landing approach start point determination unit 64 re-estimates the approach direction component of the wind speed at that point in FINAL_REG in Embodiment 1 when the final approach starts. From this result, it is possible to adjust the timing of opening the parachute to descend to the landing target point.

  Thus, according to the present embodiment, even when the parachute is opened and lowered, the parachute opening altitude and the parachute opening speed are added to the parameters for determining the landing approach distance, The drone can be automatically landed at the target landing point with the shortest approach distance suitable for the weather conditions.

  As described above, in this embodiment, when landing using a parachute, the wind speed at that time is estimated again at the start of the final approach, and the automatic opening of the parachute can be adjusted so as to eliminate the deviation of the landing point due to the wind. The landing method was explained.

Finally, a hardware configuration example of the computer 6 shown in the first to third embodiments will be described.
FIG. 9 is a diagram illustrating an example of hardware resources of the computer 6 illustrated in the first to third embodiments. The configuration in FIG. 9 is merely an example of the hardware configuration of the computer 6, and the hardware configuration of the computer 6 is not limited to the configuration described in FIG. 9 and may be another configuration.

In FIG. 9, the computer 6 includes a CPU 911 (also referred to as a central processing unit, a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, and a processor) that executes a program. The CPU 911 is connected to, for example, a ROM (Read Only Memory) 913, a RAM (Random Access Memory) 914, a communication board 915, and a magnetic disk device 920 via the bus 912, and controls these hardware devices. Depending on the operation of the computer 6, the CPU 911 may be connected to a display device, a keyboard, a mouse, an FDD (Flexible Disk Drive), a compact disk device (CDD), a printer device, and a scanner device. Further, instead of the magnetic disk device 920, a storage device such as an optical disk device or a memory card read / write device may be used.
The RAM 914 is an example of a volatile memory. The storage media of the ROM 913, FDD, CDD, and magnetic disk device 920 are examples of non-volatile memories. These are examples of a storage device or a storage unit.
The communication board 915, the keyboard, the scanner device, the FDD, and the like are examples of the input unit and the input device.
The communication board 915, the display device, the printer device, and the like are examples of an output unit and an output device.

The communication board 915 can wirelessly communicate with a ground communication station, for example. The communication board 915 may be connectable to a LAN (Local Area Network), the Internet, a WAN (Wide Area Network), etc., for example, when the drone 1 is on the ground.
The magnetic disk device 920 stores an operating system 921 (OS), a program group 923, and a file group 924. Depending on the operation of the computer 6, a window system may be stored in the magnetic disk device 920. The programs in the program group 923 are executed by the CPU 911, the operating system 921, and the window system.

The program group 923 stores a program for executing the function described as “˜unit” in the description of the first to third embodiments. The program is read and executed by the CPU 911.
In the description of the first to third embodiments, the file group 924 includes “determination of”, “calculation of”, “comparison of”, “update of”, “setting of”, and “estimation of”. ”,“ Determining ”, etc., information, data, signal values, variable values, and parameters indicating the results of processing are stored as“ ˜file ”and“ ˜database ”items. The “˜file” and “˜database” are stored in a recording medium such as a disk or a memory. Information, data, signal values, variable values, and parameters stored in a storage medium such as a disk or memory are read out to the main memory or cache memory by the CPU 911 via a read / write circuit, and extracted, searched, referenced, compared, Used for CPU operations such as calculation, calculation, processing, editing, output, printing, and display. Information, data, signal values, variable values, and parameters are stored in the main memory, registers, cache memory, and buffers during the CPU operations of extraction, search, reference, comparison, calculation, processing, editing, output, printing, and display. It is temporarily stored in a memory or the like.
In addition, the arrows in the flowcharts described in the first to third embodiments mainly indicate input / output of data and signals, and the data and signal values are the RAM 914 memory, FDD flexible disk, CDD compact disk, magnetic Recording is performed on a recording medium such as a magnetic disk of the disk device 920, other optical disks, mini disks, DVDs, and the like. Data and signals are transmitted online via a bus 912, signal lines, cables, or other transmission media.

  In addition, what is described as “˜unit” in the description of the first to third embodiments may be “˜circuit”, “˜device”, “˜device”, and “˜step”. , “˜procedure”, and “˜processing”. That is, what is described as “˜unit” may be realized by firmware stored in the ROM 913. Alternatively, it may be implemented only by software, or only by hardware such as elements, devices, substrates, and wirings, by a combination of software and hardware, or by a combination of firmware. Firmware and software are stored as programs in a recording medium such as a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, and a DVD. The program is read by the CPU 911 and executed by the CPU 911. That is, the program causes the computer to function as “to part” in the first to third embodiments. Alternatively, the computer executes the procedure and method of “to part” in the first to third embodiments.

  As described above, the computer 6 shown in the first to third embodiments includes a CPU that is a processing device, a memory that is a storage device, a magnetic disk, a keyboard that is an input device, a mouse, a communication board, and a display device that is an output device, a communication board, and the like. As described above, the function indicated as “to part” is realized by using these processing device, storage device, input device, and output device.

It is a figure which shows the structural example of the unmanned aircraft which concerns on Embodiment 1-3 of this invention. It is a figure which shows the structural example of the computer which concerns on Embodiment 1-3 of this invention. It is a flowchart which shows the landing procedure which concerns on Embodiment 1-3 of this invention. It is a figure which shows the altitude change in each phase by Embodiment 1 of this invention. It is a figure which shows the flight locus in the horizontal surface in each phase by Embodiment 1 of this invention. It is a flowchart which shows the landing procedure which concerns on Embodiment 1-3 of this invention. It is a figure which shows the flight locus in the horizontal surface in each phase by Embodiment 2 of this invention. It is a figure which shows the altitude change in each phase by Embodiment 3 of this invention. It is a figure which shows the hardware structural example of the computer which concerns on Embodiment 1-3 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Unmanned aerial vehicle, 2 GPS antenna, 3 GPS receiver, 4 Pitot tube, 5 Pressure gauge, 6 Computer, 7 Control rudder, 11 Airspeed detection means, 12 Ground speed detection means, 13 Speed direction detection means, 61 Speed information Input unit, 62 wind speed / wind direction estimating unit, 63 storage unit, 64 landing approach start point determining unit, 65 navigation control unit.

Claims (6)

A computer mounted on an unmanned aerial vehicle equipped with an airspeed detecting means for detecting an airspeed, a ground speed detecting means for detecting a ground speed, and a speed direction detecting means for detecting a speed direction,
A wind speed for estimating a wind speed and a wind direction based on the air speed detected by the air speed detection means, the ground speed detected by the ground speed detection means, and the speed direction detected by the speed direction detection means. A wind direction estimation unit;
A storage unit for storing a landing approach start altitude at which the unmanned aircraft starts descent to a landing target point;
In accordance with the estimated wind speed estimated by the wind speed and wind direction estimating unit, the landing approach distance from the landing approach starting point to the landing target point where the unmanned aircraft starts to descend to the landing target point is determined, and the determined landing approach distance And a landing approach start point determination unit that determines a landing approach start point based on the estimated wind direction estimated by the wind speed and wind direction estimation unit and the landing approach start altitude stored in the storage unit ,
The wind speed / wind direction estimation unit
The wind speed when the unmanned aircraft descends to the landing target point based on the air speed detected when the unmanned aircraft is turning at the cruise altitude above the landing target point, the ground speed, and the speed direction; Estimating the wind direction, the first estimated wind speed and the first estimated wind direction, the air speed detected when the unmanned aircraft is turning at the landing approach start altitude after descending to the landing approach start altitude, and the ground Estimating the wind speed and the wind direction when descending to the landing target point of the unmanned aircraft based on the speed and the speed direction, the second estimated wind speed and the second estimated wind direction,
The landing approach start point determination unit
The landing approach start point is determined using the first estimated wind speed and the first estimated wind direction, and between the first estimated wind speed and the second estimated wind speed, and between the first estimated wind direction and the second estimated wind direction. If the difference is less than a predetermined threshold, a new landing approach start point is determined using the second estimated wind speed and the second estimated wind direction, and the difference is A computer that determines to stop the landing sequence when the threshold is equal to or greater than the threshold value . The storage unit further includes:
The airspeed during descent when the unmanned aircraft descends to the landing target point and the descent speed when the unmanned aircraft descends to the landing target point are stored,
The landing approach start point determination unit
The landing approach distance is determined based on the estimated wind speed estimated by the wind speed and wind direction estimation unit, the airspeed during descent stored in the storage unit, the landing approach start altitude, and the descent rate. The computer according to claim 1. The storage unit
Storing location information of an accessible range in which the unmanned aircraft can enter,
The landing approach start point determination unit
The landing approach start point is determined based on the position information of the accessible range stored in the storage unit so that the landing descent trajectory to the landing target point is within the accessible range. The listed calculator. The landing approach start point determination unit
The computer according to claim 3 , wherein a turning trajectory of a turn performed before the unmanned aircraft descends from a landing approach start point is determined within an accessible range. The calculator is
It is mounted on an unmanned aerial vehicle that descends by opening a parachute from a predetermined altitude when landing and descending.
The storage unit
Airspeed at descent when the unmanned aircraft descends to the landing target point, descent speed when the unmanned aircraft descends to the landing target point, and parachute opening altitude at which the unmanned aircraft opens the parachute , Remembering the parachute opening speed when opening the parachute,
The landing approach start point determination unit
The estimated wind speed estimated by the wind speed and wind direction estimation unit, the airspeed during descent stored in the storage unit, the landing approach start altitude, the descent speed, the parachute opening altitude, the parachute opening umbrella descent speed, The computer according to claim 1, wherein the landing approach distance is determined based on The computer according to any one of claims 1 to 5 is mounted,
An unmanned aerial vehicle that descends from a landing approach start point determined by an onboard computer and automatically landing at a landing target point.

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