JP2007050841A - Small rotary wing aircraft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small rotary wing aircraft (flying object) capable of sufficiently flying against even large wind resistance by adding simple structure, allowing positional control. <P>SOLUTION: In addition to a main rotor, a small propeller (rear propeller) approximately horizontally rotating is provided on an end part opposite to a flying direction of the aircraft (flying object). In the rear propeller, an air frame, i.e., the main rotor is inclined (with the nose down) in an advance direction, and thrust of the main rotor and that of the small propeller are overlapped to support its own weight. The aircraft is configured so as to fly against the wind resistance with an advance direction component of the thrust of the small propeller. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  This invention increases the thrust force against the wind and enables position control in a small rotorcraft that flies while maintaining balance by the action of two main rotors rotating in opposite directions along the vertical axis. Is related to the configuration.

  In recent years, every time natural disasters such as earthquakes, storms and floods, landslides, volcanic eruptions, tsunamis, and forest fires have occurred, the need for prompt recognition of these occurrences has been screamed. Means are sought.

  A rescue helicopter is effective only to rescue the victim, but it is desirable to use an unmanned small aircraft (flying object) when collecting information immediately after a disaster.

  Requests for such small and highly autonomous unmanned aerial vehicles are not only from various disaster sites, but also from fields such as agriculture, livestock farming, and aerial photography.

For example, as an aircraft (flying object) that can be used in each field as described above, an area adjustment means that can adjust the projected area that receives the downward flow generated by the rotation of these two rotor blades below the two rotor blades is adjustable. There is a remotely operated unmanned small rotorcraft that can be controlled to move up and forward by control, that is, a small low-speed flying object (Patent Document 1).
JP 11-115896 A

Although there is a request for a small unmanned flying object as shown in the above-mentioned Patent Document 1 from various fields, generally, when an aircraft (flying object) is downsized, the influence of wind resistance increases. It was difficult to fly or maintain position (hovering, etc.), and there were restrictions on usage.

The present invention provides a small rotary wing aircraft (flying body) which can fly by overcoming it even if the resistance of the wind is large by adding a simple configuration and can control the position.

According to the present invention, two main rotors that are coaxially provided along an axis extending in a substantially vertical direction of a small rotary wing aircraft (flying body) and rotate in opposite directions in a substantially horizontal direction, and the flight direction of the aircraft A rear propeller mounted on the opposite end, which rotates in a substantially horizontal direction, and a pitching moment is generated in the fuselage by the rotation of the rear propeller to tilt the fuselage (main rotor) forward, and the main rotor at that time The self-weight is supported by the vertical upward thrust of the aircraft, and the aircraft is made to fly forward by the forward thrust by the main rotor and the rear propeller.

Further, in the present invention, the rear propeller can be tilted so that the attitude and position of the fuselage can be controlled more efficiently by controlling the tilt angle.

As described above, according to the configuration of the present invention, the pitching moment is generated in the aircraft by the function of the rear propeller, and the aircraft is tilted forward with respect to the flight direction of the aircraft. The aircraft is tilted, and the vertical axis to which the main rotor is attached is also tilted. As a result, the aircraft is levitated by the upward thrust generated by the main rotor, and the forward flight is generated by the forward thrust generated by the main rotor and the rear propeller. It is possible to respond sufficiently to head winds such as forward flight or hovering.

FIG. 1 is an overall perspective view of a small rotary wing aircraft (flying body) 11 according to an embodiment of the present invention, and FIG. 2 is a perspective view of a state in which a duct 12 is removed from the aircraft body 11. .

The airframe 11 is configured by attaching the duct to a main body 13 on which a camera or a rotation drive mechanism, a rotation control mechanism, or the like is mounted, for example. The duct 12 is formed of, for example, a thin-walled polystyrene foam donut-shaped cylinder or the like, and protects the main rotor 15 portion, regulates the airflow, and protects the rotor portion from contact with the human body or the like.

The duct 12 is supported and fixed to the main body 13 by two holding members 17 and 18 that support the main rotors 14 and 15 and are on a substantially horizontal plane orthogonal to the axis of the rotary shaft 16 extending in a substantially vertical direction. . Therefore, the holding members 17 and 18 are located on the diameter line of the duct 12 formed in the donut shape, and support the duct 12 from the lower surface.

The main rotors 14 and 15 are provided in two upper and lower stages on the same axis of the rotary shaft 16, and the rotary shaft 16 rotationally drives the lower main rotor 15 and rotatably supports the upper main rotor 14. The main rotor 14 is rotationally driven by a rotary shaft 19 inside the rotary shaft 16, and the main rotors 14 and 15 rotate in the opposite directions. The rotary shafts 16 and 19 rotate and drive the respective rotary blades by a motor in the main body 13.

These main rotors 14 and 15 are composed of two blades 14a, 14b, 15a and 15b, and the control in the yaw direction and the thrust direction can be performed by changing the number of rotations of the upper and lower main rotors 14 and 15. it can.

The upper main rotor 14 is connected to the stabilizer 20 so that a cyclic pitch input is given from the stabilizer 20 so as to keep the attitude of the airframe horizontal. The blades 15a and 15b are provided with vertical and horizontal cyclic pitch inputs from a servo motor, whereby the airframe performs pitch and roll motions.

In the above configuration, the rotorcraft can fly, but in this configuration, the stability to the wind is low. Therefore, in the present invention, the rear propeller 21 as shown in FIG. It is.
The rear propeller 21 is attached substantially horizontally to the rotating shaft 23 of the motor 22 provided in the rear portion with respect to the traveling direction of the airframe as shown in the figure. However, the rear propeller can be easily tilted in the traveling direction. Is possible.

In this configuration, when the rear propeller 21 at the rear of the aircraft is rotated, a vertically upward thrust is generated. As a result, a force to lift the aircraft rear, that is, a moment around the center of gravity of the aircraft is generated. That is, the main rotor is largely tilted forward, and the forward component of the thrust of the main rotor is added to the forward component of the thrust of the rear propeller, so that a large thrust is generated and the resistance of wind acting on the airframe can be overcome.

Next, referring to the schematic explanatory diagram of FIG. 3, the aerodynamic force generated in each part of the airframe of the present invention described above, and the moment around the body center of gravity G generated by the aerodynamic force will be described. In this figure, the same reference numerals as those in FIGS. 1 and 2 denote the same elements as those in these figures, and the aircraft itself is shown slightly tilted in the traveling direction for convenience of explanation.

In FIG. 3, M1 is a moment generated around the center of gravity G of the fuselage by the thrust N1 generated by the main rotors 14 and 15, and M2 is a moment generated around the center of gravity of the aircraft by the thrust N2 similarly generated by the rear propeller 21. M3 is a moment (head-lowering moment) for further lowering the aircraft generated by the resistance (aerodynamic force) N3 received by the aircraft leaning forward.

In other words, the balance of the pitching moments around the center of gravity G of the fuselage consists of three moments: two moments, the moment associated with the operation of the rear propeller, the head-lowering moment due to the wind resistance, and the head-up moment due to the main rotor. Can be realized.

Considering the relationship between the forces acting on the aircraft flying in the direction of travel in terms of vectors, it can be considered as shown in FIG.

In this figure, N1 is a thrust (vector) generated by the main rotors 14 and 15, N2 is a thrust (vector) generated by the rear propeller 21, N1 + N2 is a combined thrust (vector) of these, and then Mg is a flight. It shows the gravity of the body (airframe). Eventually, the combined thrust (vector) becomes N1 + N2 + Mg as shown in the figure when there is no wind resistance. Next, since the N3 resistance force is generated by the wind resistance, the thrust shown by the bold line in the figure is obtained.

Here, when N1 + N2 + Mg + N3 is a zero vector, it indicates a flight at a constant speed including hovering, and when this vector is not a zero vector, it is flying with an acceleration.

The pitching moment around the center of gravity of the aircraft generated by the rear propeller and the magnitude of the forward and upward components of the thrust can be adjusted according to the angle at which the rear propeller 21 is attached to the aircraft and the number of rotations thereof. In accordance with the aerodynamic performance of the rotor blades, the appropriate rear propeller mounting angle and rotational speed are adjusted.

As a result, the pitching moment around the center of gravity of the aircraft generated by the rear propeller and the magnitude of the forward and upward components of thrust can be adjusted according to the rotational speed of the rear propeller during the flight of the aircraft, and the wind speed (resistance force) or The rotational speed of the rear propeller is adjusted according to the required forward speed.

Next, the operation of the small rotary wing machine in the main body 13 having a rotation drive mechanism, a rotation control mechanism, etc. will be briefly described with reference to FIG.

The microcomputer 51 receives the signal from the global positioning system (GPS) 52 and the signals from the azimuth meter 53 and the altimeter 54 as inputs, and the upper main rotor motor 55 for driving the upper main rotor 14 and the lower main rotor. 15 generates signals for controlling the lower main rotor motor 56 that drives the motor 15, the cyclic pitch servo motor 57 that changes the angle of attack of the main rotor, and the rear propeller motor 22, respectively.

Also provided are a yaw axis late gyro 58 that gives commands to the main rotor motors 55 and 56, and a roll / pitch axis late gyro 59 that sends a signal to the cyclic pitch servo motor 57 to change the angle of attack of the main rotor.

In the above configuration, the position is measured by the GPS 52 and the direction of the nose is measured by the direction meter 53. The output of the microcomputer 51 drives the main rotor motors 55 and 56 and directs the nose to the target position. Further, the output of the microcomputer 51 drives the rear propeller motor 22 and advances toward the target position. As a result of measuring the body position with the GPS 52, when the deviation from the target position is small, the output of the microcomputer 51 can drive the cyclic pitch servomotor 57 and move toward the target position.

Further, when the altitude is lower than the set altitude, a speed-up signal is transmitted from the microcomputer 51 by a signal from the altimeter 54, and the rotor motors 55 and 56 of the main rotors 14 and 15 are driven to increase their altitudes. When the altitude is higher than the set altitude, the speed of the rotor motor is reduced in reverse.

The yaw axis late gyro 58 emits a command signal to the main rotor motors 55 and 56 in order to stop the vibration around the yaw axis of the airframe to attenuate the vibration around the yaw axis, and the roll / pitch axis late gyro 59 is In order to attenuate the vibration around the roll and pitch axes, the cyclic pitch servomotor 57 is controlled.

In general, when an aircraft is downsized, the effect of wind resistance increases, making it difficult to fly. However, in the rotorcraft of the present invention, a double rotorcraft having a total weight of 200-400 g and a rotor blade diameter of 35 cm. In this case, position control was possible at a wind speed of 2 m / s.

In order to achieve this, in the present invention, the rear propeller is mounted rearward in order to generate a pitching moment for tilting the airframe, i.e., the main rotor. This thrust is superimposed on the forward thrust of the main rotor, resulting in a stronger thrust that can sufficiently resist the wind.

In the rotary wing machine with the above configuration, even if there is a countermeasure against wind, the rear propeller can obtain a strong thrust, and the field of use under limited conditions as in the past can be expanded. .

It is a perspective view of the rotary wing machine of this invention. It is a perspective view of the state which removed the duct of the rotary wing machine of FIG. It is a figure explaining the force and moment which act on the rotary wing machine of this invention. It is a figure explaining the force (vector) which acts on the gravity center of the rotary wing machine of this invention. It is explanatory drawing of the rotation control of this rotary wing machine, and a drive control mechanism.

Explanation of symbols

11 Small rotorcraft (aircraft)
12 Duct 13 Main body 14, 15 Main rotor 16 Rotating shaft 17, 18 Holding member 19 Rotating shaft 20 Stabilizer 21 Rear propeller 22 Rear propeller motor 23 Rear propeller rotating shaft 51 Microcomputer 1, 2
52 GPS
53 Direction meter 54 Photometer 55 Upper main rotor motor 56 Lower main rotor motor 57 Cyclic pitch servo motor 58 Yaw axis late gyro 59 Roll / pitch axis late gyro M1, M2, M3 Moment Mg, N1, N2, N3 force (vector)
S Traveling direction G Aircraft center of gravity

Claims (2)

    Two main rotors that rotate coaxially along an axis extending in a substantially vertical direction of the flying object, and a rear propeller that rotates in a substantially horizontal direction and is mounted at an end opposite to the flying direction of the flying object. And generating a pitching moment for tilting the main rotor with the rotational thrust of the rear propeller, and causing the flying object to fly forward with the upward thrust of the main rotor and the forward thrust of the main rotor and the rear propeller. Characteristic small rotorcraft     2. The small rotorcraft according to claim 1, wherein the rear propeller is mounted so as to be tiltable in a flight direction from a substantially horizontal direction.

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