JP2020118641A - Multi-copter - Google Patents

Abstract

To enable accurate positioning of a multi-copter (rotary-wing airplane) in a place separated from a wall under the non-GPS environment such as an indoor place or a place below a bridge and in a space where sufficient luminous energy cannot be taken.SOLUTION: A multi-copter has: a range finder 40 using a laser or a milli-wave, in which 2-parallel beams or 2-beams forming an included angle θare emitted from 1-point radially and simultaneously or sequentially, and a distance to a measured object is measured; an angle calculation module 42 for finding an angle θy formed to the measured object of a machine body on the basis of a difference of a distance to a measured object of the parallel 2-beams found by the range finder 40 or the distance to the measured object of the radially emitted 2-beams and the included angle θ; and a control unit 43 for finding a displacement amount with a target value from the distance measured by the range finder 40 and the θy calculated by the angle calculation module 42, and performing interrupt instruction to a flight controller 44 as a horizontal movement amount and a rotation amount.SELECTED DRAWING: Figure 8

Description

The present invention relates to a rotary wing machine (commonly called a multicopter) equipped with a plurality of rotors, for example, three or more rotors. More specifically, the present invention relates to improving the flight attitude of a multicopter.

A multicopter, which is also called an autonomous aircraft or a drone, is capable of hovering and autonomous flight capable of three-dimensional movement (Non-Patent Document 1). For this reason, in recent years, the use of multicopters has been expanding in aerial photography, surveying, agriculture, logistics, relay stations, and infrastructure inspection/maintenance.

For example, when inspecting a place that is difficult for people to approach because it is dangerous at high places such as the bottom surface of a bridge or the inner wall surface of a tunnel, or when inspecting work at nuclear facilities where people cannot easily approach, the multicopter is used. Wide-ranging, rapid, inexpensive, and safe inspections are being considered using.

The multicopter is a GNSS (including Global Positioning Satellite System, GPS) sensor that calculates the position, latitude, longitude, and altitude of the aircraft by receiving radio waves transmitted from satellites, and measures the aircraft's altitude and flight speed. Atmospheric pressure sensor, ultrasonic sensor that calculates the distance from the sensor to the object by comparing the time required from the transmission of ultrasonic waves to the speed of sound (allowing altitude control and obstacle detection), positioning cameras and obstacles An optical sensor that captures the condition of the ground surface with a detection sensor and stabilizes the aircraft's horizontal maintenance and takeoff and landing (effective in situations where the use of GPS radio waves is uncertain), compass (magnetic field (magnetic field) A magnetic sensor that measures the direction to determine the direction, an inertial sensor that measures the rotation speed, and a gyro sensor that controls the roll, pitch, and yaw axes, and an acceleration sensor that detects the tilt of the aircraft from the correlation between acceleration and gravity. It is installed as needed to enable autonomous flight.

An unmanned aerial vehicle landing and landing device for inspecting a closed space and a closed space inspection system using an unmanned air vehicle capable of safely and efficiently inspecting a closed space such as a sewer pipe facility have been proposed (for example, Patent Document 1). .. This inspection system uses manholes located at both ends of the sewer pipe space to be inspected to extend the tips of the transmitting and receiving antennas into the sewer pipe, so that the operator can operate the unmanned aerial vehicle controller outside the sewer pipe. Operate the unmanned aerial vehicle to fly in the sewer pipe, receive image data (in-pipe video) and measurement values from the cameras and sensors mounted on the unmanned aerial vehicle, and display it on the controller of the unmanned aerial vehicle. It was confirmed and further recorded. In a closed space such as a sewer pipe, it is often an environment in which the amount of light is insufficient. Therefore, it is desirable to install a lighting device that can illuminate the surroundings by remote control.

In addition, as a technology that enables autonomous flight in a non-GPS environment, three-dimensional map creation technology (
There is SLAM (Simultaneous Localization and Mapping) (for example, Non-Patent Document 2). This SLAM technology is to fly autonomously while creating a three-dimensional map using the information obtained from two laser scanners of horizontal scanning and vertical scanning mounted on the aircraft.

JP, 2018-1967, A

Hotaka Yoshitake, "Basic movement of drone｜Elevator/Throttle/Aileron/Ladder/Tilt operation", [December 3, 2018 search], Internet <URL:https://www.youtube.com/watch?v= hNhzgCLMnSo〉 Kenzo Nonami, "Current Situations and Challenges of Drone Technology and Business Front", Editing/Publishing: Japan Science and Technology Agency, Published: February 01, 2017, Information Management 2017.2.vol. 59 no. 11. p.755-763, Internet <URL:https://www.jstage.jst.go.jp/article/johokanri/59/11/59_755/_pdf> [Search on December 12, 2018]

However, in a non-GPS environment such as indoors or under a bridge where radio waves from satellites cannot be received, since the GNSS sensor or GPS cannot be used, the position, latitude, longitude, and altitude of the aircraft cannot be determined. Positioning is performed by measuring the distance with the camera, ultrasonic sensor, and infrared sensor built into the camera, and confirming the direction from the camera image, but the upper limit of the distance that can be measured accurately is mounted on the multi-copter. The camera is about 10 m, the ultrasonic sensor is about 4 m, and the infrared sensor is about 5 m. Therefore, in a non-GPS environment such as indoors or under a bridge, and in a space where a sufficient amount of light cannot be obtained or in a large space (a space far exceeding 10 m from the wall, for example, 40 m or more), the multicopter is mounted. The camera cannot be used and positioning cannot be performed accurately.

Also, in the case of a multicopter that autonomously flies while creating a three-dimensional map by SLAM technology, the device is large and takes up space, and the weight is too heavy and the load is too large, resulting in reduced flight time and unstable flight. There's a problem.

One of the most important issues with multicopters is battery capacity and duration. In addition to many sensors and cameras, if a lighting device with sufficient light intensity is installed, a large battery is required, which further increases the weight of the battery and further decreases the flight time of the multicopter and the stability of flight. It will be lacking.

Furthermore, until now, there has been no means for obtaining the angle between the wall surface of the object to be measured and the multicopter. For this reason, it is necessary to confirm the direction by the image of the camera, but even if the camera has sufficient brightness, it is about 10 m, and it cannot be used when it is further away. Therefore, it cannot be used until it comes close to the wall surface of the object to be measured, but since its position cannot be known until then, there is a problem that it cannot be determined which way to fly.

Therefore, it is an object of the present invention to provide a multi-copter that enables accurate positioning even in a place away from a wall in a non-GPS environment such as indoors or under a bridge and in a space where a sufficient amount of light cannot be obtained. And

In order to achieve such an object, a multi-copter is used to measure the distance to an object to be measured by radiating two parallel beams or two beams forming an included angle θ ₀ from one point radially or simultaneously. Distance measurement using a laser or millimeter wave, and the difference in distance between the two parallel beams measured by the range finder, or the measurement target of two radially radiated beams The angle calculation module that determines the angle θy formed by the airframe with respect to the measured object based on the distance and the included angle θ ₀ , and the displacement between the distance measured by the rangefinder and θy calculated by the angle calculation module and the target value It has a control unit for determining the amount and for instructing an interruption to the flight controller as the horizontal movement amount and the rotation amount.

Here, the rangefinder is preferably a rider.

Further, the multicopter is preferably provided with a thruster for converting the downwash into a thrust at a position where the downwash is received.

Further, the thruster is a movable blade that rotates about a horizontal axis that is orthogonal to the downwash flow direction, and the movable blade is preferably rotated by an actuator that is driven by remote control.

The multi-copter of the present invention is mounted in a multi-copter indoors or under a bridge (under a non-GPS environment) and in a wide space where the amount of light is not sufficient (a space far exceeding 10 m from a wall, for example, 40 m or more). Since the distance to the wall can be measured and the angle θy formed with the wall can be obtained by the laser or the millimeter wave, the positioning can be performed accurately even at a place 40 m or more away from the wall.

Also, if a thruster that converts downwash into thrust is provided, the aircraft can move horizontally while maintaining the horizontal posture, so that the angle θy formed by the distance to the object to be measured can be accurately measured in real time. The object to be measured can be freely moved in any direction while approaching the object to be measured or maintaining a constant angle and distance between the body and the object to be measured.

It is a schematic explanatory drawing which shows one Embodiment of the multi-copter concerning this invention seeing from the left side. It is a top view of the same multicopter. It is a schematic explanatory drawing of the magnet device mounted in a multicopter, (A) shows an ON state, (B) shows an OFF state. It is a principle diagram which calculates|requires the distance to a to-be-measured object by the laser mounted in the same multicopter, (A) is a top view, (B) is a principle of the method of calculating|requiring the angle which a laser beam and a to-be-measured object make. It is explanatory drawing which shows an example. It is a flowchart figure which shows an example of the inspection flight mode of the same multicopter. It is explanatory drawing which shows an example of the principle which radiate|radiates two or three beams radially and calculates|requires the angle formed with the distance to a to-be-measured object, (A) is a top view, (B) is description of the calculation method. It is a figure. It is explanatory drawing which shows another principle which radiates two beams radially and calculates|requires the angle formed with the distance to a to-be-measured target object. It is explanatory drawing which shows an example of the mechanism which calculates|requires the angle formed with the distance to a to-be-measured target object, and controls a multicopter.

Hereinafter, the configuration of the present invention will be described in detail based on an embodiment shown in the drawings. In the present specification, left and right, up and down, front and back are determined with the camera or measuring instrument (including various sensors such as an ultrasonic probe) mounted on the multicopter as the front.

(First embodiment)
FIG. 1 shows an example of an embodiment of the multicopter of the present invention. The multicopter according to this embodiment is a quadcopter having four propellers 1, a control unit 2 provided at the center, and a motor 4 and a propeller 1 arranged in each of X-shaped frames 3 extending radially from the control unit 2. There is. Although not shown, the control unit 2 is equipped with various controllers such as an ESC (Electronic Speed Controller) and a flight controller (FCS) that control the rotation speed of the motor 4, a transmitter/receiver, a battery, and the like. A gate-shaped leg frame 5 called a skid is provided, and the camera 6 and various sensors are suspended so as to be protected by the leg frame 5. The camera 6 may be built in the airframe 20, but in the case of the present embodiment, it is installed in the camera gimbal (camera stabilizer/stabilizer) 7 so as to be able to capture a stable image. Has been.

The multicopter includes a GNSS (including Global Positioning Satellite System, GPS) sensor that receives radio waves transmitted from satellites to determine the position, latitude, longitude, and altitude of the aircraft 20, the altitude of the aircraft 20, and the flight speed. An atmospheric pressure sensor for measurement, an ultrasonic sensor that calculates the distance from the sensor to altitude control and obstacle detection, an image of the ground surface state, and stabilizes the horizontal maintenance and takeoff and landing of the aircraft 20. Positioning cameras and optical sensors such as obstacle detection sensors, magnetic sensors that measure the direction of the magnetic field (magnetic field) (so-called compass), measure the rotation speed, and control the roll, pitch, and yaw axes. A gyro sensor that is used, an acceleration sensor that detects the inclination of the body 20 from the correlation between acceleration and gravity, and the like are mounted as necessary, and autonomous flight is possible.

In the case of the present embodiment, a guide frame 8 also serving as a propeller guide is attached to the front side of the machine body 20. The guide frame 8 is, for example, an L-shaped wire frame when viewed from the side and a gate-shaped wire frame when viewed from the front and the plane, and in the case of the present embodiment, the bottom side of the leg frame 5 (that is, the ground or floor during landing). It is attached to the front side of the portion (contacting the surface) 5a so as to project forward.

Further, in the case of the present embodiment, the guide frame 8 comes into contact with the bent portion (which is the tip end position in the horizontal direction) 8a where the fall prevention part 8v extending in the vertical direction and the constant interval maintaining part 8h extending in the horizontal direction intersect. Type sensor, for example, an ultrasonic probe 9 for measuring the plate thickness is attached. The guide frame 8 presses the side of the fall prevention part 8v parallel to the rotation axis of the propeller 1 against an object to be measured (not shown), such as a wall surface, to prevent the body 20 from approaching and rolling, and to prevent the multi-copter and the object from rotating. It functions to keep a constant distance from the object to be measured. The sensor 9 mounted on the bent portion 8a of the guide frame 8 is not particularly limited to the ultrasonic probe, and any sensor may be mounted as necessary.

Further, the airframe 20 is provided with at least one or a pair of thrusters (saile) 10. The thruster 10 is provided at a position where it receives a downward airflow (downwash) generated by the thrust of the multicopter in the vertical direction, and tries to obtain the thrust in the horizontal direction by using the force of the downwash. Is. That is, the thruster 10 is a means for obtaining thrust using downwash, and is composed of, for example, plates and blades as shown in FIGS. 1 and 2. In the case of the present embodiment, in consideration of the weight balance of the machine body 20, the thruster 10 includes the ultrasonic probe 9 and the guide frame 8 mounted on the rear side of the leg frame 5, that is, the front surface (front side) of the leg frame 5. It is provided laterally at a remote position (that is, the rotation shaft of the motor is arranged in the left-right direction).

Here, in the case of the present embodiment, the thruster 10 is composed of movable blades provided with the drive motor 11, and the angle of the thruster can be rotated about the horizontal axis by driving the motor so that the downwash from the propeller 1 can be performed. It is possible to adjust the thrust that is generated. That is, it is possible to adjust the magnitude of thrust generated by changing the inclination of the thruster 10 and the presence/absence of thrust generation. Further, in the case of the thruster 10 including the movable blade, the direction of the thrust can be reversed by setting the inclination of the blade on the opposite side. That is, the thruster 10 can be moved forward or backward as long as it can be rotated at least 45 degrees forward and backward (90 degrees in total).

In the present embodiment, the downwash of the left and right propellers 1 on the rear side of the leg frame 5 is evenly received in order to obtain a thrust force for pressing the ultrasonic probe 9 on the front side straight against the object to be inspected. Is equipped with a pair of thrusters 10. However, the thruster 10 is not particularly limited to this. That is, the thrusters are symmetrically arranged on the right side and the left side of the rear portion of the machine body 20 so that no rotational force is generated in the machine body 20, but the invention is not particularly limited to this, and one drive motor equalizes the downwash of the left and right propellers. It may be one wing of the area and length to receive. Further, as shown in FIG. 2, when the number of movable blades is two, the rotation does not occur in synchronization with the case of advancing toward the object to be measured or retreating away from the object to be measured. It is preferable to do so, and when it is desired to rotate, it can be realized by controlling individually.

Further, although not shown, as an example, the thruster 10 may be vertically oriented to the side of the body 20 (that is, the rotation axis of the motor may be in the front-back direction) so as to generate thrust in the left-right direction of the body 20 in some cases. It may be equipped). That is, at least one thruster or a pair of thrusters may be provided so as to receive the downwash equally between the front propeller and the rear propeller on at least one side of the machine body 20. For example, one bottom of the skid is equipped with a thruster that receives the downwash of the front propeller and a thruster that receives the downwash of the rear propeller, or there is a single thruster that receives the downwash of the front and rear propellers at the same time. It may be provided with a thruster. In this case, it is possible to move the machine body 20 horizontally in the left-right direction while maintaining the horizontal posture.

In addition, in the case of the present embodiment, since the angle of the thruster 10 is variable, the magnitude and direction of the generated thrust can be adjusted. In addition, the movement may be synchronized between the pair of thrusters 10 that receive the downwash of the left and right propellers 1, or may be separately driven in some cases. In this case, it is possible to provide a difference between the thrusts generated on the left and right, and it can be used as a rudder. It should be noted that the thruster 10 of the movable wing does not generate thrust that pushes the fuselage 20 in the horizontal direction in either case by standing up (vertical direction) or lying down (horizontal direction). However, in order to stabilize the machine body 20, it is preferable to erect the thruster 10 because the thruster 10 does not need to be pushed down by downwash.

The thruster 10 may include a plurality of thrusters that generate thrust in two directions orthogonal to each other, for example, a thruster that generates thrust in the front-rear direction and a thruster that generates thrust in the left-right direction. When a plurality of movable thrusters that generate thrust in two directions orthogonal to each other are provided, as a rudder that enables horizontal movement of the body 20 in the front-rear direction, the left-right direction, or the combined direction thereof. Alternatively, it can be used as a speed adjusting means.

Further, in the case of the present embodiment, the guide frame 8 and the thruster 10 are arranged on the same axis. For example, the constant spacing maintaining portion 8h of the guide frame 8 and the motor 11 of the thruster 10 are attached to the front and rear portions of the bottom side of the leg frame 5. As a result, a force point exists on the extension axis of the constant spacing maintaining portion 8h extending in the horizontal direction of the guide frame 8, so that the multicopter moves horizontally while hovering and moves beyond the bending portion that is the tip of the machine body 20. When the sound wave probe 9 comes into contact with the wall surface of the object to be measured, even if the force point and the action point are on the same axis, the machine body 20 is hard to turn. Therefore, it is possible to press the ultrasonic probe 9 at the tip straight against the wall surface of the object to be measured without directly contacting it and bring them into close contact (they can be pressed neatly from the front). Then, the measurement by the ultrasonic probe can be made accurate. This is not limited to the ultrasonic probe 9, and the same effect can be obtained with other sensors.

Here, as shown in FIG. 8, for example, the multi-copter includes a microcomputer (also referred to as a micro controller, MCU, or microcomputer) 41 connected to a flight controller 44 via a UART (Universal Asynchronous Receiver Transmitte) and a motor. A motor driver 11 for driving the driver 49 and the thruster 10 is mounted. Since the control of the airframe by the radio control device (propo) 48 of the multicopter is usually performed using the frequency of 2.4 GHz band, the control of the motor 11 does not interfere with the control of the multicopter main body, for example, a frequency band of 920 MHz. It is preferable that the command is issued at. Therefore, a command is issued at a frequency of 920 MHz by a control device separate from the propo 48, for example, by the parameter input PC 46 arranged on the ground side or by switching the used radio frequency band of the multicopter's propo 48. The control of the motor 11 may be controlled by an instruction from the parameter input PC 46 by, for example, switching the instruction from the microcomputer 41 to be prioritized by interrupting from the transmitter 48, or by an instruction from the propo 48. Based on the instruction from the microcomputer 41 via the flight controller 44, the operation may be performed via the motor driver 49. In the case of the present embodiment, the parameter input PC 46 and the microcomputer 41 are provided with the wireless communication microcomputers 47 and 45, and the transmission and reception of the control signal of the motor 11, that is, the switching operation of the thruster 10 is performed.

According to the multi-copter configured as described above, the thruster 10 allows the horizontal movement in the front-rear direction and the horizontal movement in the left-right direction without tilting the body 20 (that is, keeping the horizontal posture). It can be possible.

For example, when the multi-copter arrives at a predetermined position in the infrastructure inspection point by the normal flight control mode, or when the ultrasonic probe contacts the wall surface of the measured object (so-called inspection surface), the propeller of the multi-copter is The flight controller 44 is switched from the flight control mode to the inspection control mode by operating 48 to determine the priority of the interrupt and instructing it, and the flight controller 44 is switched to follow the instruction from the microcomputer 41. That is, the flight control mode in which the four motors are independently speed-controlled is switched to the inspection control mode in which the four motors are commonly speed-controlled. In the inspection control mode, the speed of the motor 4 for generating the lift force by the minimum necessary propeller 1 for parallel movement along the wall is controlled as necessary, and the thruster 10 applies a contact force.

In general, when a multicopter approaches a wall surface, a force that attracts it hydrodynamically acts (Coanda effect), which tends to cause imbalance. However, in the multicopter of the present embodiment, the thrust generated by the slitter 10 makes contact with the inner wall surface. Therefore, it is possible to effectively use the suction force instead of resisting the suction force on the inner wall surface.

Since the guide frame 8 keeps a constant distance between the multi-copter and the object to be measured, and the thrust is generated by the thruster 10, the camera mounted on the multi-copter 1 in this state shows the state of the inner wall surface. The thickness is obtained by taking a picture or using an ultrasonic probe. In addition, the damage condition of the inner wall surface is inspected by various inspection tools mounted on the multicopter and the data is acquired.

Further, the multicopter uses thrusters 10 to obtain thrust to move up and down or horizontally along the wall. As a result, the multicopter can be moved along the wall surface of the inspection object. At this time, since the four propellers of the multicopter only need to control the height position, complicated control during multidimensional flight of the multicopter 1 is not necessary.

Since the multi-copter according to the present embodiment can be vertically moved or horizontally moved in a state where the front sensor or the like is lightly pressed and brought into contact with the multi-copter, the multi-copter 1 along the structure can be moved forward and backward while maintaining a horizontal posture. Movement to the left and right as well as up and down can be realized.

(Second embodiment)
During hovering, the multicopter sways slightly up and down, front and back, or left and right. Furthermore, when the multicopter approaches the wall surface, the force that attracts it hydrodynamically acts (Coanda effect), and it is easy to lose the balance. On the other hand, in order to inspect the wall surface, if the posture of the multi-copter is not stable, the operation is not easy and there is a risk that the inspection work will be hindered. Therefore, in order to perform accurate inspection and measurement, suction means and fixing means should be provided on the machine body 20 or an equipment attached to the machine body 20, for example, a guide frame or the like, and the multicopter body should be adsorbed on and supported by the object to be measured. May be desired. In order to meet such a demand, a multi-copter in which a vacuum suction device is mounted on the front surface of the machine body 20 so as to maintain a constant distance during measurement by adsorbing to a surface to be inspected (special feature) is also proposed. Open 2017-193330). However, when the vacuum suction device is mounted, the size of the device becomes large and a drive source and its power source are required, so the load capacity increases, the weight balance of the machine body 20 deteriorates, and the stability of flight is impaired. However, there is a problem that it is difficult to attract the flying body to a predetermined position without obtaining a sufficient suction force on the uneven suction surface. Therefore, a lightweight and compact adsorption means that does not require a power source is desired. The present embodiment responds to such a demand, and is intended to propose a lightweight and compact adsorption means that does not require a power source.

When the object to be measured is a magnetic material such as a steel plate or a steel pipe, the machine body 20 of the multicopter can be easily fixed by magnetic attraction. In particular, attraction by a permanent magnet is advantageous because it does not require a power source as compared with the case where a vacuum device or the like is mounted. Moreover, while the multicopter is held by the permanent magnet, the propeller of the multicopter can stop rotating, which saves the battery.

However, the use of a permanent magnet in a multicopter is considered unfavorable because the compass error due to the leakage magnetic flux causes a problem. A magnetic sensor (so-called compass) that measures the direction of a magnetic field (magnetic field) and obtains the azimuth is essential to the multicopter for attitude control. For this reason, it is usually unthinkable to install a permanent magnet that distorts the magnetic sensor. Further, the suction means needs to be easily detachable from the object to be measured by remote control. From this point of view, it seems that the adoption of the electromagnet is a proper choice, but it requires a power source and, in the case of the same size, has a problem that the attraction force becomes smaller than that of the permanent magnet.

Therefore, the present inventors, as the magnet device 12, house a fixed permanent magnet 15 and a permanent magnet 14 rotatable so that the magnetic poles are exchanged in a housing 13 also serving as a yoke, as shown in FIG. I decided to use a two-layer permanent magnet. This two-layer type permanent magnet makes one of the two layers of permanent magnets arranged above and below, for example, the upper layer permanent magnet 14 rotatable by a motor, and when the upper and lower permanent magnets 14 and 15 are arranged in the same pole. Is configured such that the magnetization direction is perpendicular to the work 16. Therefore, when the two layers of permanent magnets 14 and 15 have the same pole, a strong attractive force is generated, and when they have different polarities, the magnetization direction becomes parallel to the work 16, so that the work 16 can be easily detached and attached. You can When the yoke 13 is located near the magnets 14 and 15, the magnetic flux is concentrated in the yoke 13 having a high magnetic permeability without leaking to the atmosphere, so that the attractive force is increased. On the other hand, this two-layer type permanent magnet has almost no problem of leakage magnetic flux when combined so that the overlapping magnets 14.15 have different polarities, and therefore has little influence on the compass. Although not shown, the permanent magnet 14 on the rotating side is connected to, for example, a stepping motor or the like, and is rotatably provided every 180°. Further, a permanent magnet position detection sensor (not shown) is provided, and the magnetic pole is controlled to be rotatable by 180°. The stepping motor of the magnet device 12 is controlled using a frequency band different from the control frequency band of the main body of the multicopter, for example, a frequency band of 920 MHz. For example, it is preferable to switch the used radio frequency band of the multicopter radio 48 or to switch the magnet device by a control device separate from the radio transmitter 48, for example, a parameter input PC 46 arranged on the ground side.

In the case of the multi-copter of the present embodiment configured as described above, by obtaining thrust by the thruster 10, it is possible to horizontally move in any direction while hovering without tilting the machine body 20. When the ultrasonic probe 9 is pressed diagonally against the object to be measured, the plate thickness cannot be accurately measured, but the thrust generated by the thruster 10 causes the multicopter to move horizontally without tilting, so the ultrasonic probe 9 is pressed against the wall faced. Moreover, since the force point exists on the same axis, the force that tends to tilt is not generated. The multicopter can make stable contact. Then, the vicinity of the ultrasonic probe 9 can be adsorbed on the wall surface of the object to be measured, and the machine body 20 can be stopped there.

Normally, the elevator and aileron of the multicopter are moved by tilting the machine body 20 by changing the rotation speeds of the front and rear or left and right propellers. For this reason, it is difficult to press the machine body 20 parallel to the wall surface of the object to be measured. Therefore, even if the guide frame 8 is provided, if the vertical side, that is, the fall prevention portion 8v does not have a sufficient length (that is, height), the multi-copter is pressed against it. Immediately after that, the machine body 20 turns around the tip of the guide frame 8 as a starting point, and the four propellers hit the wall. For this reason, there has been no type of multicopter equipped with a sensor that can be continuously pressed against the inspection object with a constant force on the front side of the multicopter.

(Third Embodiment)
In addition, the conventional multi-copter measures the position indoors or under a bridge (under a non-GPS environment) by measuring the distance with a camera, an ultrasonic sensor, or an infrared sensor incorporated in the multi-copter. However, the upper limit of the distance that can be accurately measured is about 10 m for the camera mounted on the multicopter, about 4 m for the ultrasonic sensor, and about 5 m for the infrared sensor. Also, the camera needs to be bright enough to work in low light. Therefore, there is a problem that positioning cannot be performed in a non-GPS environment and in a wide space where a sufficient amount of light cannot be obtained. In particular, if the angle between the beam line and the object to be measured, that is, the angle θy formed between the machine body 20 and the object to be measured cannot be obtained, it is difficult to even specify the moving direction.

Therefore, in the present embodiment, in a non-GPS environment such as indoors or under a bridge, and in a space where a sufficient amount of light cannot be obtained, it is possible to accurately perform positioning in a place away from a wall, for example, at least about 40 m to 100 m. It realizes a copter. In the multicopter of the present embodiment, a non-GPS is provided by mounting a rangefinder using one or two lasers or millimeter waves, for example, LiDAR (Light Detection and Ranging, Laserimaging Detection and Ranging: hereinafter referred to as lidar). It is possible to perform positioning in a space where a sufficient amount of light is not available for using the camera or in a wide space (for example, positioning at a position of at least 40 m to 100 m from the wall) under the environment.

That is, for example, as shown in FIG. 8, the multicopter according to the present embodiment is mounted on the airframe, and two parallel beams or two beams forming an included angle θ ₀ from one point are radially or simultaneously or sequentially. A distance meter 40 that uses a laser or a millimeter wave to radiate and measure the distance to the object to be measured, and the difference in distance between the two parallel beams obtained by the distance meter 40 to the object to be measured or radial The angle calculation module 42 for obtaining the angle θy formed by the airframe with respect to the object to be measured based on the distance between the object to be measured and the included angle θ _{0 of} the two beams radiated in It has a control unit 43 that obtains a displacement amount from a target value from θy calculated by the distance and the angle calculation module, and interrupts the flight controller 44 as a horizontal movement amount L and a rotation amount θ. In the present embodiment, the angle calculation module 42 and the control unit 42 are realized by the microcomputer 41 mounted on the multicopter body 20. However, in some cases, the angle calculation module 42 and the control unit 43 are different from each other. It is also possible to configure the parameter input PC 46 on the ground side to exchange data via the wireless communication microcomputers 47 and 45. In the present embodiment, the angle calculation module 42 and the control unit 42 are realized by the microcomputer 41 mounted on the multicopter body 20. However, in some cases, the angle calculation module 42 and the control unit 43 are different from each other. The ground-side parameter input PC 46 may be configured to exchange data with the microcomputer 41 mounted on the airframe via the wireless communication microcomputers 47 and 45.

The distance from the object to be measured and the angle θy are written as parameters in advance in the control program of the microcomputer 41 mounted on the multicopter. The parameters are rewritten as necessary from a remote PC, for example, the parameter input PC 46. The PC is equipped with a microcomputer for wireless communication, and commands are issued at a frequency band of 920 MHz, for example, which does not interfere with the control of the multicopter body. The multicopter radio controller (propo) is instructed by determining the priority of interruption. A program for controlling the thruster 10 is also written in the microcomputer 41, and is provided so as to perform a switching operation in response to an instruction from the ground side PC 46.

In the case of the present embodiment, as the range finder 40, a range finder using a laser or a millimeter wave, for example, a measurement technology called LiDAR (Light Detection and Ranging, Laserimaging Detection and Ranging: hereinafter referred to as lidar) is used. This lidar is generally commercially available as a laser distance sensor module. For example, by emitting a laser beam to detect the reflected wave from the measured object and measuring the time until the reflected wave returns, the measured object can be measured. It utilizes a technique for measuring the distance to the object (time-of-flight method), and the distance to the measurement point is calculated by the microcomputer on the board, and the desired communication method such as the I ² C standard ( Serial communication standard) is unitized so that it can be output by serial communication. Generally, a laser ranging sensor, a microcomputer, a laser light source, etc. are mounted on a single board, and the algorithms required for controlling the laser ranging sensor are all incorporated in the firmware to complete processing on the device. Has been converted.

As the rider 40, it is preferable to use a solid-state type rider, especially a MEMS (Micro Electro Mechanical System) type rider. The MEMS solid-state lidar is a device that integrates sensors, actuators, and electronic circuits on a single silicon substrate, glass substrate, organic material, etc. by microfabrication technology, and is suitable for mounting on a multicopter. There is. A MEMS solid-state lidar generally scans laser light using an electromagnetic MEMS mirror that uses a mirror, a coil, a magnet, etc. (LiDAR's MEMS type and Solid State type, explanation of features and differences https:/ /jidounten-lab.com/y_6506). This solid-state type lidar does not have a mechanical rotation mechanism and replaces the mechanical part with semiconductor technology or optical technology, so it can only detect within the irradiation angle range of the laser, so the detection area is several. Although it is as narrow as 10 degrees, there is no particular problem in the case of the present embodiment as long as an included angle θ ₀ of several tens of degrees can be realized between two beams.

The rider 40 is arranged at an arbitrary position of the body, for example, in the case of an embodiment in which two riders (not shown) are arranged in parallel with each other so as to irradiate the measurement object with parallel beams 21 and 22, It is fixed to the leg frame 5. Further, when a single solid-state MEMS type lidar is provided, it is preferable to mount it on the lower part of the machine body or the camera gimbal.

In the case of the present embodiment, the distance information obtained by the rider 40 is supplied to the microcomputer 41 by I ² C. Then, the angle calculation module 42 configured in the microcomputer 41 determines the angle θy formed with the object to be measured by the following arithmetic processing, and the control unit 43 further sets the displacement amount with respect to the target value, that is, a predetermined position and angle to the multicopter. The horizontal movement amount L and the rotation amount θ required to move the aircraft are obtained, and the flight controller 44 is instructed to interrupt. The target value is written in advance as a parameter on the control program or firmware of the microcomputer. In the case of the present embodiment, the guide frame 8 at the tip of the machine body 20 is pressed against the object to be measured, thereby positioning the object to be measured. On the other hand, the difference (displacement amount) between the distance information from the rider 40 and the angle θy formed by the object to be measured calculated by the distance information is obtained as the rotation amount θ of the multicopter and is instructed to the flight controller 44. The target value can be remotely rewritten from the parameter input PC 46 on the ground side through the wireless communication microcomputers 47 and 45 as required. In addition to the normal control of the multicopter, the propo 48 performs an operation (switching operation) of whether or not to give priority to the instruction from the microcomputer 41 in addition to interrupting.

For example, in the case of an embodiment in which two riders (not shown) are arranged and fixed in parallel to each other on the leg frame 5 so as to irradiate the parallel beam 21, 22 to the object to be measured, The distance to the object to be measured is measured by the return time. Further, the distance x0 at the irradiation source between the two beams 21 and 22 is a known fixed value determined when the rider is mounted on the leg frame 5. Therefore, when the two beams 21 and 22 return in the same amount of time, the multicopter is perpendicular to the wall surface 24 of the object to be measured, and when there is a deviation in the return time, FIG. As shown in (B), it can be determined that the beams 21 and 22 are inclined. Therefore, the angle θy formed with the wall 24 is obtained from the time difference between the two beams 21 and 22 as shown in the following equation (1).

θ _y =tan ⁻¹ (x ₀ /δ _y )... (1)
Where x ₀ is the distance between the two riders and is known.
Further, δ _y is the difference (y ₂ −y ₁ ) between the _two beams.

For example, as shown in FIG. 4A, the rider may irradiate the forward parallel laser beams 21 and 22 with a lateral laser beam 23 (that is, the rider) 23 to the left or right. It may be provided as described above. In this case, the position of the machine body 20 can be maintained at a constant distance and distance from both the front wall 24 and the left side wall (or the right side wall) 25. Of course, a plurality of riders may be mounted so as to irradiate a plurality of parallel laser beams laterally.

From the above relationship, if the angle θy formed between the aircraft body 20 and the wall surface is obtained, the rotation of the aircraft body 20 can be corrected by the ladder operation even under a non-GPS environment, and the aircraft body 20 can be controlled so as to face straight ahead. .. Then, by thrusting the thruster 10 in a state in which the thruster 10 is directed straight to the wall 24, thrust can be generated and the multicopter can be advanced. On the contrary, the machine body 20 can be rotated so as to form an arbitrary angle θy. Conventionally, there has been nothing to find the angle between the beamline and the wall surface, that is, the angle θy between the body 20 and the wall surface under the non-GPS environment.

As described above, the angle θy formed by the airframe 20 and the wall 24, the distances y1 and y2 between the airframe 20 and the wall 24, and the distance x between the airframe 20 and the wall 25 shown in FIG. 4A are obtained. It is also possible to perform the inspection by moving vertically along the wall 24 while maintaining the situation in which these relationships are specified. For example, an example of the inspection mode is shown in FIG. First, it means an operation mode in which only the atmospheric pressure sensor, the compass, and the gyro are effective (that is, the operation in a situation where the GPS, infrared sensor, and ultrasonic sensor cannot be used, and is referred to as A mode in the present specification, for example. ) (Step 101). Then, the angle formed by the ladder and the wall is set to θy (step 102). When the angle formed by the wall is not θy, the mode returns to A mode (step 103). On the other hand, when the angle formed by the wall is θy, the elevator controls the distance to the wall 24 to be y (step 104). If the elevator does not control the distance to the wall to be y, the formed angle θy is maintained, and the parts other than the ladder are made effective (step 105). In other words, it does not rotate, but moves only forward, backward, left, and right (rudder fixed/ineffective, elevator and aileron effective). On the other hand, the aileron controls the distance to the wall 25 to be x (step 106). If not controlled, θy and y are maintained, and only the throttle and aileron are enabled (step 107). When continuing the control, θy, y and x are maintained and only the throttle is made effective (step 108). The functions that can be controlled as described above are limited, and finally θy, y, and x are maintained and only the throttle is enabled. This allows the multicopter to only move up and down (inspect) along the wall 24.

Further, in the case of the embodiment of FIG. 4, the angle θy formed with the object to be measured is obtained from the difference between the distances of the two parallel beams to the object to be measured, but in some cases from one point By radiating at least two beams forming the included angle θ ₀ simultaneously or sequentially in a radial manner, the angle θ y formed by the aircraft with respect to the measured object is determined based on the distance to the object to be measured and the included angle θ _0. May be requested. For example, the angle θy formed by instantaneously rotating the beam of one rider, or by simultaneously irradiating two beams from two riders crossing each other at an included angle θ ₀ can be obtained.

For example, as shown in FIG. 6A, instead of two beams, one beam is scanned by a rotating mechanism or an optical scanning mechanism using semiconductor technology or optical technology to scan the object to be measured of the machine body. It is also possible to find the angle θy formed with the distance. That is, one MEMS solid-state type lidar is rotated by a fixed angle (θ ₀ ) to measure the length of the three beams 30, 31, 32, that is, the distance (y ₁ ) to the object to be measured. , can be obtained _(y 2), by obtaining the _{(y 3),} angle formed qy the beam and the wall based on the following equation (2) or (3). In this case, the rider's rotation angle θ ₀ is known.

y ₂ <y ₃
θy=tan ⁻¹ {(y ₁ −y ₂ cos θ ₀ )/(y ₂ sin θ ₀ )} …(2)
y ₂ >y ₃
θy=tan ⁻¹ {(y ₁ −y ₃ cos θ ₀ )/(y ₃ sin θ ₀ )} …(3)

Further, as shown in FIG. 7, by instantaneously rotating the beam of one rider, from the two line segments (L ₁ and L ₂ ) 33 and 34 and the included angle (θ ₀ ) thereof, for example, The angle qy formed by the beam and the wall can be obtained based on the equations (4) to (8). Of course, when two solid-state type lidars whose beam emitting directions are fixed are arranged so as to cross each other with a included angle θ ₀ , the angle θy formed by the machine body with respect to the measured object can be similarly obtained.
L ₂₁ =L ₁ cos θ ₀ …(4)
L ₂₂ =L ₂ −L ₂₁ =L ₂ −L ₁ cos θ ₀ …(5)
L ₀ =L ₁ sin θ ₀ …(6)
θ ₁ =θ ₁₁ +θ ₁₂ =tan ⁻¹ (L ₂₁ /L ₀ )+tan ⁻¹ (L ₂₂ /L ₀ ).
…(7)
_{θy = 180 ° -θ 1 -θ 0} /2 ... (8)

Note that these calculations are executed by the angle calculation module 42. The angle calculation module 42 is constructed by the microcomputer 41 by starting an arithmetic program that executes the above-described arithmetic expression, and arithmetic processing is processed. An inspection program for executing the flowchart shown in FIG. 5 is also written in the microcomputer 41. Further, by running the control program on the microcomputer 41, the distance to the measured object measured by the rider 40 and the angle θy obtained by the angle calculation module 42 and the target value written as a parameter A control unit 43 for determining the deviation and instructing the flight computer 44 as the rotation amount θ is configured.

According to the angle calculation module 42 configured as described above, how much the aircraft rotates based on the distances of the two beams of the rider 40 to the wall of the measured object and the angle θy formed by the aircraft with respect to the measured object. Since an instruction as to what should be done is issued to the flight controller 44 via the control unit 43, it becomes possible for the multicopter to move from the object to be measured to a predetermined position. On the other hand, according to the judgment of the user, the presence/absence of horizontal movement, that is, the presence/absence of rotation of the thruster 10 is instructed from the ground via the parameter input PC 46, and the horizontal movement is performed.

According to the multi-copter having the above configuration, it is possible to perform horizontal movement in the front-rear direction and horizontal movement in the left-right direction without tilting the machine body 20 (that is, while maintaining the horizontal posture). Further, by using laser waves or millimeter waves, the distance to the object to be measured and the angle between the wall surface of the object to be measured and the laser beam (that is, the inclination of the machine body 20 with respect to the wall) θy even in a non-GPS environment. Can be asked. Further, by obtaining the inclination/angle θy of the machine body 20 with respect to the wall, it is possible to direct the sensors, camera, etc. to the front by a ladder so as to face the object to be measured. If necessary, the angle θy formed with respect to the object to be measured, the distance y to the wall 24, the distance x to the wall 25 is maintained at x, and only the throttle is made effective. That is, a multi-copter is installed along the wall 24. Only the vertical movement (inspection) is possible.

The above-described embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention. For example, in the present embodiment, the present invention has been mainly described by taking an example in which it is applied to an unmanned small multi-copter equipped with the camera 6 as an inspection means and various sensors, but the present invention is not particularly limited to this, and people and luggage can be It goes without saying that it can also be applied to a large multicopter that is carried and carried. And when carrying out as a transportation multi-copter or a riding multi-copter, it is preferable to provide a plurality of movable thrusters that generate thrust in two directions orthogonal to each other. In this case, the movable thruster 10 can be used as a rudder that enables horizontal movement of the machine body 20 in the front-rear direction, the left-right direction, or a combined direction thereof while maintaining the horizontal state, or as a speed adjusting means.

Further, in the above-described embodiment, a multi-copter (quad-copter) provided with four propellers has been mainly described as an example, but the present invention is not particularly limited to this, and the present invention can be applied to other types of multi-copters. Needless to say, can be applied. That is, the present invention can be applied to hexacopters (6 propellers), octocopters (8 propellers), and the like.

Further, in the above-described embodiment, the thruster 10 is a movable blade driven by a motor, but it is not particularly limited to this and may be a fixed blade in some cases. For example, a thrust force for constantly advancing the machine body 20 may be generated by equipping a pair of or one thruster that receives the downwash of the left and right propellers on the rear side of the skid at a constant angle. When the fixed wing is used, thrust is generated at the same time when the multicopter floats, and the aircraft 20 is constantly moved horizontally while keeping it horizontal in a certain direction. It can be pressed straight against the inspection object. Therefore, it is convenient when there are many movements that always move forward, for example, in the case of a dedicated multi-copter for inspecting a wall surface. In the case of the thruster composed of this fixed blade, since the motor 11 is not necessary, the weight of the machine body 20 can be reduced, and the power source for the motor 11 is also unnecessary. Also, when you want to fly outdoors or away from walls, etc., if you do not want to move forward, turn the front propeller more strongly than the rear propeller (try to move backward), cancel forward movement Then you can hover. That is, the function of the thruster of the fixed wing can be canceled by performing the operation of not moving forward.

Further, in the above-described embodiment, an example in which a laser such as a lidar is used as an optical sensor for measuring the distance has been described, but the invention is not particularly limited to this, and a millimeter wave may be emitted.

Further, in the case of the above-described embodiment, the magnet device is used to attract the vicinity of the sensor to the surface of the object to be measured and stop the machine body 20 there. However, since no magnetic flux leaks, the gyro may be out of order. Since it is not provided, it can be attached to the tip of the winch, for example.

Further, in the above-described embodiment, the L-shaped guide frame 8 also serving as a propeller guide is attached to the machine body 20, but the present invention is not limited to this, and depending on the case, the fall prevention portion extending in the vertical direction may be provided. Alternatively, a sensor such as an ultrasonic probe may be provided to protrude from the leg frame 5 without the 8v, and may be provided separately from the propeller guide.

The multicopter according to the present invention has been mainly described for the case of being applied to an inspection in a room or under a bridge (under a non-GPS environment), but various inspection work outdoors not only indoors, and many others. It goes without saying that the facilities that form the basis of industry and social life can be inspected. For example, the range of application is extremely wide, such as bridges spanning rivers, expressway viaducts, tunnel inner wall surfaces, various buildings, factory buildings, towers, and the like.

Further, in the above-described embodiment, the description has been given mainly with reference to an example of an original drone, that is, a multi-copter in which a person flies by remote scanning without boarding. It goes without saying that it can also be applied to multi-copters, vertical take-off and landing type automobiles and aircraft, etc. In this case, the thruster can also function as a rudder.
If the maximum loading capacity is large, power consumption will increase.

1 propeller 4 motor 5 leg frame (skid)
6 camera 7 camera gimbal (camera stabilizer/stabilizer)
8 Guide frame 8a Bent part (it becomes the tip position in the horizontal direction)
8h Horizontally-extending constant distance maintaining unit 8v Fall prevention unit 9 Ultrasonic probe (sensor)
10 Thruster 11 Motor of thruster 12 Magnet device 13 Housing (yoke)
14 Rotating magnet 15 Fixed magnet 21,22 Parallel laser beam 23 Laser beam 24,25 Wall of measured object 30, 31, 32 One laser beam scanned within a constant rotation angle

Claims (4)

A distance meter using a laser or millimeter wave that measures the distance to the object to be measured by radiating two parallel beams or two beams forming an included angle θ ₀ from one point radially or simultaneously. , The difference between the distances of the two parallel beams to the object to be measured obtained by the range finder, or the distances of the two radially radiated beams to the object to be measured and the included angle θ ₀ . An angle calculation module for obtaining an angle θy formed by the airframe with respect to the object to be measured based on, and a displacement amount between a distance measured by the rangefinder and a target value calculated from θy calculated by the angle calculation module to determine a horizontal value. A multi-copter comprising: a control unit for instructing a flight controller to interrupt a movement amount and a rotation amount. The multicopter according to claim 1, wherein the rangefinder is a rider. The multicopter according to claim 1 or 2, wherein a thruster that converts the downwash into thrust is provided at a position where the downwash is received. 4. The multicopter according to claim 3, wherein the thruster is a movable blade that rotates about a horizontal axis that is orthogonal to the flow direction of the downwash, and the movable blade is rotated by an actuator that is driven by remote control. ..