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CN-115720649-B - Unmanned aerial vehicle control method with multi-degree-of-freedom flight mode

CN115720649BCN 115720649 BCN115720649 BCN 115720649BCN-115720649-B

Abstract

A control method for a multi-degree-of-freedom flight mode unmanned aerial vehicle includes a fuselage section on which a battery is mounted, the forward direction of the unmanned aerial vehicle being set to an x-axis, a plurality of rotors provided around the fuselage section and aligned in the z-axis direction of each rotation axis, an x-axis tilting mechanism section for tilting the plurality of rotors about axes parallel to the x-axis, a y-axis tilting mechanism section for tilting the plurality of rotors about axes parallel to the y-axis, a first drive motor section for driving the y-axis tilting mechanism section, a second drive motor section for driving the x-axis tilting mechanism section, and a control section for controlling the first rotor, the second rotor, the third rotor, the fourth rotor, the first drive motor section, and the second drive motor section to realize a plurality of flight modes.

Inventors

  • Li Shangjuan

Assignees

  • 李尚泫

Dates

Publication Date
20260505
Application Date
20201125
Priority Date
20200629

Claims (5)

  1. 1. A control method of unmanned aerial vehicle with multi-degree of freedom flight mode is characterized in that, The unmanned aerial vehicle comprises a body part, a battery, a driving part and a driving part, wherein the body part is provided with the battery, and the advancing direction is set as an x axis; a first rotor and a second rotor each of which is aligned in a z-axis direction of a rotation axis, and which are disposed in a first position so as to face each other with the body portion as a center when viewed from the x-axis direction; a third rotor and a fourth rotor each having a rotation axis aligned in the z-axis direction, and being disposed opposite to each other in the y-axis direction at a second position of the body portion when viewed from the x-axis direction, wherein the x-axis, the y-axis, and the z-axis are perpendicular to each other; A first frame shaft rotatably supported by the body part at the first position with a y1 axis parallel to the y axis as a center, and supporting the first rotor and the second rotor at both end portions based on respective support shafts parallel to the x axis; a second frame shaft rotatably supported by the body part about a y2 axis parallel to the y axis in the second position, and supporting the third rotor and the fourth rotor based on respective support shafts parallel to the x axis at both end portions; A third frame shaft which is provided in the z-axis direction at a distance from the first frame shaft by a plurality of first rods, and which moves by a force parallel to the y-axis so that the first rotor and the second rotor tilt about respective axes parallel to the x-axis; A fourth frame shaft provided at a distance from the second frame shaft in the z-axis direction based on a plurality of second rods, and movable based on a force parallel to the y-axis so that the third rotor and the fourth rotor tilt about respective axes parallel to the x-axis; a first driving motor unit connected to the third frame shaft and the fourth frame shaft via a first conversion mechanism unit, and configured to supply a force parallel to the y-axis direction; a second driving motor part connected via a second conversion mechanism part for providing force to the first and second frame shafts to rotate about the y1 and y2 axes, respectively, and A control unit for controlling the first rotor, the second rotor, the third rotor, the fourth rotor, the first drive motor unit, and the second drive motor unit to realize a plurality of flight modes, The control method includes setting a speed of the first rotor to the fourth rotor and a tilt angle of the first rotor to the fourth rotor in order to fly the unmanned aerial vehicle according to an inputted value; Calculating a difference between an azimuth angle of the fuselage section and a forward speed of the unmanned aerial vehicle in a trajectory, and If the difference between the azimuth angle of the fuselage section and the forward speed of the unmanned aerial vehicle exceeds a reference value, changing the inclination angles of the first rotor to the fourth rotor, reducing the difference between the azimuth angle and the forward speed of the unmanned aerial vehicle, The plurality of flight modes includes a first flight mode in which the first drive motor unit and the second drive motor unit are stopped and the speeds of the first rotor to the fourth rotor are individually controlled, and A second flight mode in which the first drive motor unit and the second drive motor unit are activated by separate control, the speeds of the first rotor to the fourth rotor are separately controlled, The first flight mode includes: A 1 st-1 st flight mode in which the fuselage section is tilted in the x-axis direction or moved in the y-axis direction; a 1 st-2 nd flight mode in which the body portion is tilted in the y-axis direction or moved in the x-axis direction; 1 st to 3 rd flight modes, for rotating the fuselage section about the z-axis, and 1 St to 4 th flight modes, for moving the fuselage section in the z-axis direction, The second flight mode includes: a 2-1 flight mode in which the fuselage section is kept horizontal, the first to fourth rotors are tilted about respective axes parallel to the x-axis, and the fuselage section is moved in the y-axis direction; A 2 nd-2 nd flight mode in which the fuselage section is kept horizontal, the first to fourth rotors are tilted about respective axes parallel to the y-axis, and the fuselage section is moved in the y-axis direction; 2 nd-3 flight modes, wherein the fuselage section is kept horizontal, and the speeds of the first rotor wing and the fourth rotor wing are independently controlled, so that the fuselage section rotates around the z-axis; 2 nd-4 th flight mode, keeping the fuselage portion horizontal, individually controlling the speeds of the first rotor to the fourth rotor, and moving the fuselage portion in the z-axis direction; 2 nd-5 th flight mode, rotating the first rotor to the fourth rotor about respective axes parallel to the x-axis, rotating the fuselage section relative to the x-axis, and And a 2-6 flight mode in which the first to fourth rotors are rotated about respective axes parallel to the y-axis, and the fuselage section is rotated about the y-axis.
  2. 2. The method of claim 1, wherein the unmanned aerial vehicle having a multiple degree of freedom flight mode, The control method further includes the steps of being input with a target pointing point; And in the process of moving the unmanned aerial vehicle according to the track, the inclination angles of the first rotor wing to the fourth rotor wing are changed in order to change the azimuth angle of the fuselage part and enable the fuselage part to continuously face the target pointing point.
  3. 3. The method of claim 1, wherein the unmanned aerial vehicle having a multiple degree of freedom flight mode, The control method further includes the steps of being inputted with an arbitrary angle pattern regarding the azimuth angle of the fuselage section; Is input into the tilt angles of the first rotor to the fourth rotor, and And changing the azimuth angle of the fuselage section by changing the inclination angles of the first rotor to the fourth rotor according to the inputted inclination angle.
  4. 4. The method of claim 1, wherein the unmanned aerial vehicle having a multiple degree of freedom flight mode, The 2 nd to 5 th flight modes include a posture in which the respective rotation axes of the first rotor to the fourth rotor are parallel to the z-axis, and the fuselage section is rotated with respect to the x-axis to maintain a state of being inclined with respect to the ground.
  5. 5. The method of claim 1, wherein the unmanned aerial vehicle having a multiple degree of freedom flight mode, The 2 nd to 6 th flight modes include a posture in which the respective rotation axes of the first rotor to the fourth rotor are parallel to the z-axis, and the fuselage section is rotated with respect to the y-axis to maintain a state of being inclined with respect to the ground.

Description

Unmanned aerial vehicle control method with multi-degree-of-freedom flight mode Technical Field The invention relates to a control method of an unmanned aerial vehicle with a multi-degree-of-freedom flight mode. Background A multi-rotor or multi-fan aircraft, known as a drone, is typically one type of helicopter having more than three rotors. Compared with the traditional single-rotor helicopter, the helicopter has the advantages that the torque and the speed of the rotor wing can be changed, and the maintenance and the operation are easy. Due to these advantages and the rapid development of electronics, the field of application of multi-rotor aircraft is also rapidly expanding. In the past, unmanned aerial vehicles with larger military dimensions are mainly used, but more civil small unmanned aerial vehicles are produced recently. The application range of the method is also expanded from shooting images to various fields such as article transportation. Among the various forms of small unmanned aircraft, in particular, multi-rotor aircraft, known as quad-rotor, have many advantages over other aircraft. The greatest advantage is that the mechanical mechanism is very simple. The four rotors do not need to trim the aircraft before flying, the mechanical vibration is not large, and the probability of part breakage caused by ageing is low. Moreover, since the quadrotors have a compact shape, mathematically easy to model, and therefore suitable for automatic flight, beginners can easily maneuver, unlike other small aircraft that require extensive training to adjust the aircraft. In addition, due to the use of multiple small propellers, it is also relatively safe for persons unskilled in handling or management. That is, the quad-rotor can be easily handled, maintained, and managed even without expertise on the aircraft or without much training in advance. Thanks to these advantages, the impact of quadrotors in small unmanned civil aircraft is expanding. Many researchers have studied the control and guidance of four rotors. First, in the control field, in order to effectively cope with characteristics of a four-rotor nonlinear model, a nonlinear system is directly controlled by a Backstepping technique or a Sliding Mode technique, and further, it is attempted to linearize the four-rotor model by Feedback Linearization (feedback linearization) and then control the same. In addition, in the guide field, not only a Flip (quick turn) operation of rotating the quadrotor body 360 degrees or more in one direction but also a delicate maneuver such as a reciprocal ball based on a specific orbit and posture can be realized. Under the contribution of numerous researchers, although multi-rotor aircraft such as four rotors can be precisely controlled and guided, the function of the multi-rotor aircraft is still to be improved. Based on the fact that the exact position and attitude of the aircraft in three-dimensional space is represented by 6 variables, the final multi-rotor aircraft system becomes a Under Actuated (under-actuated) system with input dimensions smaller than output dimensions. This fact limits the control and guidance of multi-rotor aircraft. For example, in order to accelerate a multi-rotor vehicle forward, the main body thereof must be tilted forward, and in a state in which the multi-rotor vehicle is tilted backward, no forward acceleration is generated at all. That is, the attitude and acceleration of a multi-rotor aircraft cannot be completely independent. Therefore, when a subject is photographed by attaching a camera to the main body of the multi-rotor vehicle, if the multi-rotor vehicle switches directions, the main body thereof will also tilt together, so that the photographing direction of the camera will deviate from the photographing subject. In addition, since the entire multi-rotor aircraft is required to tilt at the time of switching the direction, the responsiveness is relatively low, and thus rapid maneuver is not easy. For these reasons, additional devices capable of holding the camera according to the change of the angle of the body are used, which results in an increase in parts and costs, an increase in weight, and a reduction in the use time of the battery. In addition, since such a camera connecting device is susceptible to vibration, a dust collecting device is separately installed, and thus there is a disadvantage in that the device becomes complicated. * Related art Korean laid-open patent No. 10-2017-0061941 (2017.06.07. Public) Korean patent application No. 10-1692315 (2016.12.28. Authorized) Disclosure of Invention Technical problem to be solved The invention aims to realize various flight modes by stably providing an unmanned aerial vehicle with multiple degrees of freedom, and can keep a state of no shake without providing a separate device for installing a camera. Another object of the present invention is to minimize the air resistance experienced by the unmanned aerial vehicle by