JP7399534B1 - Aircraft control system - Google Patents

Abstract

A control system for a flying object includes a speed sensor that detects the flight speed of the flying object, a distance sensor that acquires a first distance that is a distance between the flying object and the structure, and a control unit that controls the flying object. , is provided. The control unit includes a first calculation for calculating a target speed of the flying object based on a difference between a target distance and the first distance, and a first calculation for calculating a target speed of the flying object based on a difference between the flight speed and the target speed. A second calculation for calculating acceleration and a third calculation for changing the weighting of the first calculation and the second calculation based on the target distance or the first distance are executed. The control device accelerates the flying object until the target acceleration is reached, and feedback-controls the flying object until the first distance reaches the target distance.

Description

The present disclosure relates to a control system for an aircraft.

BACKGROUND ART Control systems that use position PID control and speed PID control are conventionally known to control flying objects (for example, see Patent Document 1).

JP 2019-113992 Publication

Patent Document 1 discloses a control system for a flying object that changes the weighting of position PID control and speed PID control depending on the distance between a target position and the flying object. Patent Document 1 discloses that calculations are performed based on the difference between the target position and the position of the flying object, regardless of whether position PID control or speed PID control is executed.

However, for flying vehicles used indoors, it is necessary to consider the influence of reflected wind, which is generated when the wind generated by the flying vehicle is reflected by structures. Therefore, when the position PID control and speed PID control of Patent Document 1 are executed, the behavior of the flying object may be disturbed by the reflected wind.

An object of the present disclosure is to provide a novel control system for an aircraft that is suitable for an aircraft used indoors.

A control system for a flying object according to the present disclosure includes a speed sensor that detects the flight speed of the flying object, a distance sensor that acquires a first distance that is a distance between the flying object and the structure, and a control system for controlling the flying object. and a control unit. The control unit includes a first calculation for calculating a target speed of the flying object based on a difference between a target distance and the first distance, and a first calculation for calculating a target speed of the flying object based on a difference between the flight speed and the target speed. A second calculation for calculating acceleration and a third calculation for changing the weighting of the first calculation and the second calculation based on the target distance or the first distance are executed. The control device accelerates the flying object until the target acceleration is reached, and feedback-controls the flying object until the first distance reaches the target distance.

According to this aircraft control system, the second calculation uses the target speed calculated by the first calculation. This makes it possible to reduce the influence of reflected wind on the behavior of the flying object. Further, the control system of the aircraft changes the weighting of the first calculation and the second calculation depending on the distance to the structure or marker. This enables calculations that take into account the degree of influence of reflected wind depending on the distance to the structure.

According to the control system for an aircraft according to the present disclosure, a novel control system suitable for an aircraft used indoors can be provided.

FIG. 1 is a system diagram of a control system for an aircraft according to an embodiment of the present disclosure. FIG. 1 is a system diagram of an air vehicle according to an embodiment of the present disclosure. FIG. 2 is a block diagram showing a calculation loop for PID control according to an embodiment of the present disclosure. The figure which shows an example of the data table used for a 3rd calculation. The figure which shows an example of the target position and vector displayed on a user terminal. 5 is a flowchart showing processing executed by a control device according to an embodiment of the present disclosure.

Hereinafter, one embodiment of the present disclosure will be described with reference to the drawings.

As shown in FIG. 1, the control system 1 of the aircraft 2 includes a control device 3 of the aircraft 2, a user terminal 4, a server 6, a relay device 8, a plurality of ID markers 10, and an initial marker 12. , a temporary landing marker 14, a return marker 16, a takeoff port 18, a permanent landing port 20, and a temporary landing port 22.

As shown in FIG. 2, the flying object 2 includes at least a camera 24, an exposure device 26, a laser device (an example of a distance sensor) 28, a speed sensor 29, a battery 30, a plurality of motors 32, and a flight control device. It has a section 34. In addition to this, the flying object 2 may have a plurality of sensors such as a gyro and an acceleration sensor for detecting the attitude and speed of the flying object. In this embodiment, the flying object 2 is an unmanned multicopter equipped with four motors 32. However, the flying object 2 may be any known multicopter. The laser device 28 is a device that detects the distance (an example of the first distance) Dr to each marker or structure. However, the distance Dr may be detected by the camera 24.

The control system 1 for the flying object 2 of this embodiment is a system that inspects the structure X using the flying object 2 without using GPS in an environment where GPS (Global Positioning System) cannot be used. The structure X is, for example, a wall of a tunnel or a wall of a building such as a building. The control system 1 of the flying object 2 follows the flight path displayed on the initial marker 12, ID marker 10, temporary landing marker 14, and return marker 16 (hereinafter referred to as each marker in the specification) arranged on the structure X. This is a system that reads information and controls the aircraft 2.

The flight control unit 34 is a device for acquiring instructions from the control device 3 and controlling the flying object 2. The flight control unit 34 is actually composed of a microcomputer including a CPU, memory, I/O interface, and motor driver, and wireless communication devices such as Wi-Fi (registered trademark) and Bluetooth (registered trademark). The flight control unit 34 controls each part of the flying object 2 using a program stored in the memory. The program included in the flight control unit 34 at least performs a process of acquiring instructions from the control device 3 and controlling the plurality of motors 32 according to the acquired instructions so that the flying object 2 has a desired attitude and speed. a process of performing imaging by the camera 24, a process of measuring the distance Dr by the camera 24 or the laser device 28, a process of activating the exposure device 26, a process of acquiring the remaining battery level of the battery 30, including.

The control device 3 is a device that reads flight route information displayed on each marker and transmits a desired signal to the flight control section 34. As shown in FIG. 3, the control device 3 executes a first calculation and a second calculation to determine the target acceleration α to be instructed to the flight control unit 34. The first calculation is a calculation process that calculates the target speed Vt of the flying object 2 based on the difference between the target distance Dt and the distance Dr. The second calculation is a calculation process that calculates the target acceleration α of the flying object 2 based on the difference between the target speed Vt calculated by the first calculation and the speed Vr detected by the speed sensor 29.

Further, the control device 3 executes a third calculation that changes the weighting of the first calculation and the second calculation based on the target distance Dt or the distance Dr. The third calculation of the present embodiment is a calculation process in which each gain in the first calculation and each gain in the second calculation is set based on the target distance Dt or the distance Dr. When the control device 3 calculates the target acceleration α by performing the first calculation, the second calculation, and the third calculation, it generates a signal of the target acceleration α and transmits it to the flight control unit 34. The flight control unit 34 accelerates and decelerates the flying object 2 so as to reach the target acceleration α.

More specifically, in the first calculation and the second calculation, the control device 3 uses PID control using proportional control (P control), integral control (I control), and differential control (D control) to determine the target speed Vt. , and target acceleration (operated amount) α. In the calculation loop in FIG. 3, a term S is I control, and a term 1/S is D control. The details of the PID control will be omitted as they may be general ones. The control device 3 calculates the target speed Vt from the speed control deviation calculated by multiplying the difference between the target distance Dt and the distance Dr by a coefficient that converts the difference between the target distance Dt and the distance Dr into speed in the first calculation. In the second calculation, the control device 3 calculates the target acceleration α from the acceleration control deviation calculated by multiplying the difference between the target speed Vt and the speed Vr calculated by the first calculation by a coefficient for converting into acceleration. In this way, the control device 3 repeats such a calculation loop at predetermined time intervals and executes feedback control using the target acceleration α as the manipulated variable. Note that in the position PID control and speed PID control of Patent Document 1, speed is disclosed as the manipulated variable, but in the control system 1 for the flying object 2 of the present disclosure, the speed PID control is included in the loop of the position PID control. The difference is that a loop is incorporated and the target acceleration α is a manipulated variable.

In the third calculation, the combination of each gain of the P control, I control, and D control used in the first calculation and the second calculation is determined from the distance Dr or the target distance Dt included in the flight information acquired from the marker. Therefore, the third operation is actually executed before the first and second operations. As shown in FIG. 4, the control device 3 of this embodiment stores a table 50.

The table 50 shows the I control gain POS_Kp, the D control gain POS_Kd, the I control gain POS_Ki in the first calculation, and the I control gain POS_Ki in the second calculation in correspondence with the target distance Dt or distance Dr from the structure X or each marker. The I control gain VEL_Kp, the D control gain VEL_Kd, and the I control gain VEL_Ki are stored. In the following specification, these gains will be referred to as each gain. Each gain is set such that the smaller the target distance Dt or the distance Dr, the greater the influence of the deviation (control deviation) caused by the second calculation. In other words, the control device 3 weights the second calculation more heavily as the target distance Dt or distance Dr becomes shorter. Further, the longer the target distance Dt or the distance Dr, the more the influence of the deviation due to the second calculation may be reduced to zero. In this case, the target acceleration α may be calculated by multiplying the target speed Vr by a coefficient for converting it into the target acceleration α in the second calculation. In other words, the control device 3 always calculates the control amount according to the deviation of the first calculation. However, when the target distance Dt or the distance Dr is large (long), the control device 3 may not calculate the control amount according to the deviation of the second calculation.

When the control device 3 acquires the target distance Dt or the distance Dr, in the third calculation, it acquires each gain from the table 50 and uses it in the first calculation and the second calculation. Note that although the control device 3 of this embodiment stores each gain corresponding to the target distance Dt or the distance Dr in the table 50, the present disclosure is not limited to this. For example, the table 50 may store coefficients to be multiplied by each gain corresponding to the target distance Dt or distance Dr.

Further, the distance Dr in this embodiment is a filtered distance Drf obtained by performing complementary filtering on the distance acquired by the laser device 28. Complementary filter processing is processing that smoothes values by mixing current values and past values at a certain ratio. Complementary filtering is calculated as follows.

D1f=D1 _n ×C+D1 _n-1 ×(1-C)...Formula (1)

Here, D1 _n is the distance Dr obtained when processing the current calculation loop. D1 _n-1 is the distance Dr used in the previous calculation loop. C is a filter constant. The filter constant may be stored in the table 50 in correspondence with the target distance Dt or the distance Dr.

Note that the first to third calculations are processes for calculating the target acceleration α in the direction directly facing the structure X or each marker (X direction in FIG. 5). Therefore, the control device 3 separately performs arithmetic processing on the traveling direction (Y direction in FIG. 5) and altitude.

In addition, the control device 3 records flight history such as the direction, altitude, and distance traveled by the flying object 2 from the takeoff port 18. The control device 3 actually includes a microcomputer including an arithmetic unit 36, a storage unit 38, and an I/O interface, and wireless communication devices such as Wi-Fi (registered trademark) and Bluetooth (registered trademark) (the communication device shown in FIG. 2). section 40). The control device 3 uses the program stored in the storage section 38 to generate an instruction signal to be transmitted to the flight control section 34, and transmits it to the flight control section 34. In this embodiment, the control device 3 is provided separately from the flight control unit 34, is fixed at a desired location of the flying object 2, and is electrically connected to the flight control unit 34 wirelessly or by wire. . Thereby, the flying object 2 can be controlled using a program included in an existing multicopter. However, the control device 3 may be provided integrally with the flight control section 34.

The user terminal 4 is a personal computer used by the user to create and record a flight plan combining markers. However, the user terminal 4 may be a device such as a smartphone or a tablet terminal. The flight plan is information for the control device 3 to control the flying object 2 while reading each marker placed on the flight path. The flight plan includes at least information on the distance to the structure X or the target distance Dt to the marker. Specifically, the flight plan includes identification information displayed on the ID marker 10 and flight route information corresponding to the identification information. When the control device 3 reads the identification information of the ID marker 10, it can acquire flight route information such as the position of the next ID marker 10. When the control device 3 reads the initial marker 12, it accesses the flight plan storage location of the server 6 via the relay device 8 and downloads the flight plan.

As shown in FIG. 5, the control device 3 displays at least the position of each marker or the position of the structure It is also possible to perform processing to display the data as a vector). In FIG. 5, for example, the position of the flying object 2, the ID marker 10, the target acceleration α in the X direction, the target acceleration α2 in the Y direction, and the distance Dr of the flying object 2 are displayed. By having the control device 3 execute such processing, the user can easily visually grasp the moving direction of the flying object 2.

The server 6 is connected to the user terminal 4 via the Internet, and stores flight plans created and recorded by the user terminal 4. The server 6 is, for example, a cloud storage that is a storage device located on the Internet. The relay device 8 is a device that is connected to the control device 3 by wireless communication and to the server 6 via the Internet, and relays between the control device 3 and the server 6. In the present embodiment, the relay device 8 is placed at a construction site or the like where the flying object 2 is used.

A plurality of ID markers 10 are arranged in the structure X. A permanent landing port 20 is arranged below some of the ID markers 10. The ID marker 10 displays an image obtained by converting numbers, which are identification information, into AR markers. In addition to this, the ID marker 10 displays text or image information related to identification information. The initial marker 12 is placed at the starting point of the flight path. The initial marker 12 is provided for the control device 3 to obtain a flight plan. In this embodiment, the initial marker 12 is placed near the takeoff port 18.

The temporary landing marker 14 indicates that the aircraft 2 is in a position where it can land if an abnormality occurs. The return marker 16 is pasted at an arbitrary position on the flight path by the user when returning the flying object 2 to the takeoff position. The takeoff port 18 is located at the takeoff position as described above. The permanent landing port 20 is arranged under some of the ID markers 10 among the plurality of ID markers 10. The temporary landing port 22 is located below the temporary landing marker 14

Next, a procedure for controlling the flying object 2 by the control device 3 will be explained using FIG. 6. Note that in this embodiment, an example will be described in which the weighting of the first calculation and the second calculation is changed based on the target distance Dt.

In step S1, the control device 3 reads the initial marker 12. When the control device 3 reads the initial marker 12, it acquires a flight plan that matches the information of the read initial marker 12 (step S2). The control device 3 that has acquired the flight plan acquires the target distance Dt, which is the distance to the structure X or each marker, from the flight plan information (step S3), and advances the process to step S4.

In step S4, the control device 3 sets the weighting of the first calculation and the second calculation. Specifically, the control device 3 acquires each gain from the table 50 and substitutes it into a program that executes the first calculation and the second calculation. After setting the weighting, the control device 3 causes the flying object 2 to take off (step S5), and advances the process to step S6.

In step S6, the control device 3 reads the first ID marker 10 (an example of a first marker). The control device 3 identifies the flight route based on the flight route information displayed on the ID marker 10, flies toward the next ID marker (an example of a second marker) 10 (step S7), and executes the process in step S8. proceed.

In step S8, the control device 3 acquires the distance Dr to the structure X. The distance to the structure X may be the distance to the ID marker 10 when the first ID marker 10 (first marker) is read. The control device 3 performs complementary filter processing on the acquired distance Dr (step S9), substitutes it into the calculation loop, and advances the process to step S10.

In step S10, the control device 3 calculates the target acceleration α using the above calculation loop, and advances the process to step S11. The control device 3 gives an instruction to the flight control unit 34 using the target acceleration α as the manipulated variable, moves the flying object 2 (step S11), and advances the process to step S12.

In step S12, the control device 3 determines whether the ID marker (second marker) has been read. When the control device 3 determines that the ID marker (second marker) has been read (step S12 YES), the control device 3 returns the process to step S6, and performs a process for reading the ID marker (an example of the third marker) next to the second marker. Proceed to control. Therefore, in the second processing from step S6 to step S12, the control device 3 repeats the processing by replacing the first marker with the second marker and replacing the second marker with the third marker.

If the control device 3 determines that the ID marker (second marker) has not been read (step S12 NO), the above calculation loop is repeatedly executed at predetermined time intervals, and the flight is performed so that the target distance Dt approaches the distance Dr. The body 2 is controlled by feedback. In addition, the control system 1 for the flying object 2 of the present disclosure also executes a process of reading markers other than the ID marker 10 among the markers, but it also controls the flying object 2 so that the distance Dr becomes the target distance Dt. Since the processing to be performed is the same, the explanation will be omitted.

As explained above, according to the control system 1 for the flying object 2 of the present disclosure, the second calculation uses the target speed Vr calculated by the first calculation. Thereby, the influence on the behavior of the flying object 2 caused by the reflected wind can be reduced. Specifically, the closer the distance between the flying object 2 and the structure X, the greater the influence of the reflected wind. Therefore, the closer the flying object 2 is to the structure X, the more the flying object 2 is swept away from the structure X by the reflected wind. Therefore, when calculating the target acceleration α by performing only the first calculation based on the target distance Dt and the distance Dr, the hunting operation in which the flying object 2 repeats the behavior of approaching and moving away from the structure X due to the influence of the reflected wind. wake up However, by using the deviation between the target speed Vr and the flying object 2 based on the second calculation, this hunting operation can be easily converged.

Furthermore, the control system 1 of the flying object 2 changes the weighting of the first calculation and the second calculation according to the target distance Dt or distance Dr to the structure X or each marker. Thereby, calculations can be made that take into consideration the degree of influence of reflected wind according to the distance Dr from the structure X or each marker. Specifically, when the target distance Dt or the distance Dr is large (long), there is no influence of reflected wind. However, according to the findings of the inventors, when the control amount due to the deviation of the second calculation is included, a hunting operation occurs as the distance Dr approaches the target distance Dt. Therefore, as the target distance Dt or distance Dr increases, it is preferable to eliminate the influence of the second calculation. From this point of view, the control system 1 of the flying object 2 makes the weighting of the second calculation closer to zero according to the target distance Dt or distance Dr to the structure X or each marker. In other words, the control system 1 of the flying object 2 weights the second calculation more heavily as the target distance Dt or distance Dr to the structure X or each marker becomes closer.

As described above, according to the control system 1 for an aircraft 2 according to the present disclosure, it is possible to provide a novel control system 1 for an aircraft 2 suitable for an aircraft used indoors.

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various changes can be made without departing from the gist of the invention. In particular, the plurality of modifications described in this specification can be arbitrarily combined as necessary.

For example, in the above embodiment, a plurality of ID markers 10, initial markers 12, temporary landing markers 14, return markers 16, takeoff ports 18, permanent landing ports 20, and temporary landing ports 22 are used. Although the explanation has been given using an example in which the flying object 2 is controlled, the present disclosure is not limited thereto. Any control system may be used as long as the control system 1 controls the flying object 2.

1: Control system 2: Aircraft 3: Control device 4: User terminal 6: Server 8: Relay device 10: ID marker 24: Camera 26: Exposure device 28: Laser device (an example of a distance sensor)
29: Speed sensor 30: Battery 32: Motor 34: Flight control section 36: Calculation section 38: Storage section 40: Communication section 50: Table

Claims (5)

a speed sensor that detects the flight speed of the aircraft;
a distance sensor that obtains a first distance that is a distance between the flying object and the structure;
a control unit that controls the flying object;
Equipped with
The control unit includes:
a first calculation that calculates a target speed of the flying object based on the difference between the target distance and the first distance;
a second calculation that calculates a target acceleration of the flying object based on the difference between the flight speed and the target speed;
a third calculation that changes the weighting of the first calculation and the second calculation based on the target distance or the first distance;
Run
accelerating the flying object until the target acceleration is reached, and feedback controlling the flying object until the first distance reaches the target distance;
Aircraft control system. The control unit weights the second calculation heavier as the target distance or the first distance is shorter.
A control system for an aircraft according to claim 1. The control unit smoothes the distance acquired from the distance sensor and sets it as a first distance.
A control system for an aircraft according to claim 1 or 2. a display that displays at least the position of the structure and displays the target acceleration in the direction and size of an arrow;
Further prepare,
A control system for an aircraft according to any one of claims 1 to 3. further comprising a marker disposed on the structure and containing flight path information of the aircraft,
The distance sensor acquires the first distance that is the distance between the flying object and the structure or the marker,
The control unit controls the flying object while reading the marker.
A control system for an aircraft according to any one of claims 1 to 4.

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