A control method for aircraft tilting to level flight

Abstract

The present invention discloses a control method for changing an aircraft from tilting to level flight, comprising: after receiving a take-off signal, controlling the aircraft to take off in a multi-rotor mode to reach a preset target height; controlling the aircraft to tilt forward and accelerate at a preset target attitude angle; when it is detected that the aircraft accelerates forward and reaches a preset airspeed, controlling the target attitude angle to be horizontal, and at the same time controlling the front motor of the aircraft to start tilting, so that the front motor tilts to a horizontal state; controlling the rear motor of the aircraft to stop running, so that the aircraft enters a fixed-wing mode for flight. The present invention can solve the problem in the prior art that the process of changing an aircraft from a tilting fixed-wing mode to level flight is susceptible to external interference, and improves the anti-interference ability of the aircraft during flight, thereby facilitating the improvement of the robustness of the aircraft flight.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft, and in particular to a control method for a tilt-fixed-wing aircraft to change to level flight. Background Art

[0002] In the prior art, the steps for a tilt-fixed-wing aircraft to change from tilt to level flight during takeoff are mainly to tilt the front motor during the acceleration phase, and then switch from the multi-rotor mode to the fixed-wing flight mode after reaching the specified airspeed. However, the existing tilt-to-level flight method is easily disturbed by external factors (such as ambient wind, etc.) during the tilt switching process, which can easily lead to the failure of the aircraft to change to level flight and the phenomenon of attitude lock loss. Summary of the invention

[0003] An embodiment of the present invention provides a control method for an aircraft to change from tilt to level flight, so as to solve the technical problem that the existing aircraft is easily disturbed during the process of changing from tilt to level flight. The present invention can improve the anti-interference ability of the aircraft during the process of changing from tilt to level flight, thereby facilitating improving the robustness of the control of the tilt to level flight.

[0004] In order to solve the above technical problems, an embodiment of the present invention provides a control method for changing an aircraft from tilting to level flight, comprising the following steps:

[0005] S1. After receiving the take-off signal, controlling the aircraft to take off in multi-rotor mode to reach a preset target height;

[0006] S2. Control the aircraft to tilt forward and accelerate at a preset target attitude angle;

[0007] S3. When it is detected that the aircraft accelerates forward and reaches a preset airspeed, the target attitude angle is controlled to be horizontal, and the front motor of the aircraft is controlled to start tilting so that the front motor tilts to a horizontal state;

[0008] S4. Control the rear motor of the aircraft to stop running, so that the aircraft enters the fixed-wing mode for flight.

[0009] As a preferred solution, step S3 is specifically as follows:

[0010] Within a preset tilt switching time, the front motor is controlled by the front tilt servo to perform a tilt movement so that the front motor is tilted to a horizontal state; at the same time, the power output of the rear motor is controlled to decrease to zero.

[0011] As a preferred solution, step S1 is specifically as follows:

[0012] After receiving the take-off signal, the front motor and the rear motor are controlled to rotate, and the rotation speeds of the front motor and the rear motor are corrected in real time, so that the aircraft can dynamically and smoothly take off vertically in a multi-rotor mode to reach the preset target height.

[0013] Compared with the prior art, the beneficial effect of the embodiments of the present invention lies in that the control method for changing an aircraft's tilting to level flight provided by the present invention first tilts the aircraft to a preset target attitude angle to accelerate the flight, and after reaching the airspeed, controls the target attitude angle to maintain a dynamic horizontal state, and then controls the front motor to tilt to a dynamic horizontal state, thereby effectively improving the anti-interference capability during the multi-rotor flight change process. In addition, the control method provided by the present invention can maintain a good control effect for attitude control and heading control during the aircraft's tilting process during multiple field actual flight tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a flow chart of a control method for changing an aircraft's tilting flight to level flight in an embodiment of the present invention;

[0015] Figure 2 is a structural schematic diagram of a control method for changing an aircraft's tilting flight to level flight in an embodiment of the present invention;

[0016] The reference numerals in the accompanying drawings of the specification are as follows:

[0017] 1. Fixed wing; 2. Front motor; 3. Rear motor; 4. Multi-rotor. DETAILED DESCRIPTION

[0018] like Figure 1 and Figure 2 The preferred embodiment of the present invention provides a control method for changing an aircraft from tilting to level flight, which at least comprises the following steps:

[0019] S1. After receiving the take-off signal, controlling the aircraft to take off in multi-rotor mode to reach a preset target height;

[0020] S2. Control the aircraft to tilt forward and accelerate at a preset target attitude angle;

[0021] S3. When it is detected that the aircraft accelerates forward and reaches a preset airspeed, the target attitude angle is controlled to be horizontal, and the front motor of the aircraft is controlled to start tilting so that the front motor tilts to a horizontal state;

[0022] S4. Control the rear motor of the aircraft to stop running, so that the aircraft enters the fixed-wing mode for flight.

[0023] In an embodiment of the present invention, the aircraft is controlled to tilt forward to accelerate and reach the preset airspeed by the preset target attitude angle. At this time, at the preset airspeed, the fixed wing 1 of the aircraft has generated lift to offset the aircraft's own gravity. At this time, the target attitude angle is controlled to be horizontal, and the tilt of the front motor 2 is controlled at the same time, so that the front motor 2 tilts from the vertical position at takeoff to the horizontal position, and the upward pulling force of the front motor 2 will gradually be converted into a forward pulling force, driving the aircraft to fly forward. In this way, compared with the prior art, the embodiment of the present invention avoids the weakening of the multi-rotor attitude control force caused by the change of the multi-rotor power model caused by the acceleration of the tilting front motor 2 in the existing tilting technical solution, thereby effectively improving the anti-interference ability in the process of tilting to level flight, and the control method provided by the embodiment of the present invention can maintain a good control effect in the attitude control and heading control of the aircraft tilting to level flight process during multiple field actual flight tests.

[0024] In the embodiment of the present invention, the step S1 is specifically as follows:

[0025] After receiving the take-off signal, the front motor 2 and the rear motor 3 of the aircraft are controlled to rotate, and the rotation speeds of the front motor and the rear motor are corrected in real time, so that the aircraft can take off vertically and smoothly in a multi-rotor mode to reach the preset target height; at this time, the target attitude angle of the aircraft is horizontal.

[0026] In the embodiment of the present invention, the step S2 is specifically:

[0027] When the aircraft reaches a preset target altitude, the aircraft is controlled to tilt at a preset target attitude angle, and the rotation speeds of the front motor 2 and the rear motor 3 are controlled to control the aircraft to accelerate forward. At this time, the front motor 2 and the rear motor 3 tilt with the aircraft at the preset target attitude angle, and the front motor 2 and the rear motor 3 also tilt with the aircraft at the preset target attitude angle, but the relative position relationship between the front motor 2 and the rear motor 3 does not change.

[0028] In the embodiment of the present invention, the step S3 is specifically as follows:

[0029] When it is detected that the aircraft reaches a preset airspeed, the target attitude angle is controlled to return to a horizontal state, and the aircraft returns to a horizontal state from the tilt state of step S2. Within a preset tilt switching time, the front motor 2 is controlled by the front tilt servo to perform a tilt movement so that the front motor 2 is turned to a dynamic horizontal state. At this time, the relative position relationship between the front motor 2 and the rear motor 3 is a vertical state.

[0030] In an embodiment of the present invention, the control method of the aircraft is specifically applied to Figure 2 The process of switching the aircraft from multi-rotor mode to fixed-wing mode is as follows:

[0031] 1. The multi-rotor accelerates forward at a given inclination angle:

[0032] After the aircraft takes off in multi-rotor mode, at the preset target altitude, a target attitude angle is given, and the aircraft begins to accelerate forward at the target attitude angle. This process starts when the tilt control action is triggered and ends when the airspeed of the aircraft reaches the preset airspeed.

[0033] 2. The front motor 2 is tilted and controlled, and the aircraft changes from a multi-rotor to a fixed-wing flight mode:

[0034] When the aircraft reaches the preset airspeed and the target attitude angle returns to the horizontal state, the fixed-wing body can generate sufficient lift to offset its own gravity, control the tilt of the front tilt servo, control the front motor 2 to tilt from the vertical direction at takeoff to the horizontal direction, and gradually convert the upward pulling force of the front motor 2 into the forward pulling force. This process starts from the time when the aircraft reaches the preset airspeed and ends when the front tilt motor completely rotates from vertical to horizontal. At the same time, in this process, the power output of the rear motor 3 decays to zero over time while the front motor 2 starts to tilt.

[0035] 3. The multi-rotor mode flight is completely changed to level flight and switched to fixed-wing mode flight:

[0036] The aircraft is completely switched from multi-rotor mode to fixed-wing mode, and at the same time, the two rear motors 3 in the multi-rotor mode stop working, and the two front motors are transformed into front pulling power motors in the fixed-wing mode.

[0037] From the analysis of the power model, the attitude stabilization control of the multi-rotor flight mode mainly changes the lift of the corresponding angle by adjusting the speed of the motor in real time, so as to maintain the attitude balance of the aircraft, so the installation of the multi-rotor motor is basically in the form of vertical downward to the body of the aircraft. In the existing technology of using the tilt front motor to realize forward flight acceleration, when the motor in the multi-rotor mode has a certain inclination angle, the multi-rotor power model changes, and the power generated by the motor driving the propeller in the multi-rotor mode will only be partially distributed in the vertical direction. In this way, on the one hand, the motor on the shaft must output a larger speed to increase the power in the vertical direction to offset the gravity of the aircraft, and on the other hand, the tilt front motor will also generate a torque that makes the aircraft yaw when the pulling force of the front motor is unbalanced. Both aspects will increase the burden of stabilization attitude control. Therefore, in this way, the front pull acceleration in the multi-rotor mode is realized, which not only increases the load of the front tilt motor, but also weakens the stabilization control ability under the multi-rotor model, because only a part of the lift of the tilt propeller is converted to the vertical direction to provide lift, so using the tilt front motor to realize forward flight acceleration will weaken the attitude stabilization control ability of the multi-rotor.

[0038] The embodiment of the present invention provides a control method for changing an aircraft from tilting to level flight. By changing the tilt control logic of the aircraft, the control mode of accelerating the tilt front motor is changed to the control mode of accelerating the tilt at the target attitude angle of the aircraft, and the aircraft is controlled to accelerate forward and reach the preset airspeed at the preset target attitude angle. At this time, at the preset airspeed, the fixed wing of the aircraft has generated a lift for offsetting the gravity of the aircraft itself, and the tilting action of the front motor 2 is started at the same time, so that the front motor 2 is tilted from a vertical position to a horizontal position, and the upward pulling force of the front motor 2 will gradually be converted into a forward pulling force, driving the aircraft to fly forward. In this way, compared with the prior art, the embodiment of the present invention avoids the weakening of the attitude control force of the multi-rotor caused by the change of the multi-rotor power model by accelerating the tilt front motor 2 in the existing tilting technical solution, thereby effectively improving the anti-interference ability in the process of changing the tilting to level flight, and the control method provided by the embodiment of the present invention can maintain a good control effect in the attitude control and heading control of the aircraft tilting process during multiple field actual flight tests.

[0039] During the actual flight of the aircraft, there will be slight fluctuations due to external influences. The aircraft corrects the errors caused by external fluctuations in real time. Therefore, the horizontal, vertical, and vertical involved in the present invention are all dynamic horizontal, dynamic vertical, and dynamic vertical.

[0040] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art may make several improvements and modifications without departing from the principle of the present invention, and these are all considered to be within the protection scope of the present invention.

Claims

1. A control method for converting an aircraft's tilting flight into level flight, characterized in that: The following steps are involved: S1. After receiving the take-off signal, control the aircraft to take off in a multi-rotor mode to reach a preset target height; at this time, the target attitude angle of the aircraft is horizontal; S2. Controlling the aircraft to tilt at a preset target attitude angle and controlling the rotation speeds of the front motor (2) and the rear motor (3), thereby controlling the aircraft to accelerate forward flight; at this time, the relative positional relationship between the front motor (2) and the rear motor (3) remains unchanged; S3. When it is detected that the aircraft accelerates forward and reaches a preset airspeed, the target attitude angle is controlled to be in a horizontal state, the aircraft is restored from the tilting state of step S2 to a horizontal state, and the front motor of the aircraft is controlled to start tilting, so that the front motor (2) tilts to a horizontal state; at this time, the relative position relationship between the front motor (2) and the rear motor (3) is in a vertical state; S4. Control the rear motor of the aircraft to stop running, so that the aircraft enters fixed-wing mode flight.

2. The control method for converting an aircraft tilting flight to level flight as claimed in claim 1, characterized in that: Step S3 is specifically as follows: Within the preset tilt switching time, the front motor is controlled to perform tilt movement by controlling the front tilt servo so that the front motor is tilted to a horizontal state; at the same time, the power output of the rear motor is controlled to decrease to zero.

3. The control method for converting an aircraft tilting flight to level flight as claimed in claim 1 or 2, characterized in that: Step S1 is specifically as follows: After receiving the take-off signal, the front motor and the rear motor are controlled to rotate, and the rotation speeds of the front motor and the rear motor are corrected in real time, so that the aircraft can dynamically and smoothly take off vertically in a multi-rotor mode to reach the preset target height.

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