A Heading Control Method for an Aircraft

Abstract

The present invention discloses a heading control method for an aircraft. During the takeoff process, tilting process, and landing process, the heading angle control loop of the aircraft is turned off. Specifically, the output of the heading angle control loop in the multi-rotor mode of the aircraft is turned off, the target rate of the heading angle rate control loop is set to zero, and the dynamic heading angle rate error is corrected so that the heading angle rate of the aircraft is in a stable state. The heading control method for an aircraft provided by the present invention can improve the anti-interference characteristics and safety during the heading flight transformation process of the aircraft.

Description

Technical Field

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

[0002] A tilt-wing fixed-wing aircraft is an aircraft formed by combining the form of a fixed-wing aircraft and the form of a multi-rotor aircraft. During the multi-rotor tilting acceleration stage in the process of heading transformation of the existing such aircraft, due to the aerodynamic action generated by the added fixed-wing airfoil, an uncertain disturbing moment will be introduced to the attitude control of the multi-rotor. Therefore, during the process of heading flight transformation, it is prone to be interfered by external factors such as environmental wind, thereby increasing the correction load during the flight transformation process and leading to an increase in flight risk.

[0003] In the prior art, during the flight process of heading transformation, before the actual airspeed reaches the airspeed required for specified level flight, the automatic control of the multi-rotor plays a dominant role. At this time, the automatic control of the multi-rotor is in the mode where the roll, pitch, and heading of the multi-rotor are all in the automatic correction control mode. Due to the aerodynamic characteristics of the fixed-wing fuselage part, when affected by a crosswind, the fuselage will generate a moment that twists the nose towards the windward direction. Moreover, due to the heading locking effect of the aircraft, in order to maintain the original heading of the aircraft, the control system will always adjust and output a correction amount to resist this moment to maintain the original flight heading angle. At the same time, during the process of heading flight transformation, due to the tilting change of the front motor, the attitude control ability of the multi-rotor will also be weakened. Therefore, under the conditions that the automatic control of the multi-rotor plays a dominant role and the tilting of the front motor weakens the attitude control ability of the multi-rotor, it is extremely easy to cause the heading of the aircraft to be unlocked during flight mode switching, and even lead to the serious consequence of the entire attitude control divergence and loss of control. Summary of the Invention

[0004] A heading control method for an aircraft provided by the present invention is used to solve the technical problem that the flight transformation process of the existing aircraft is prone to interference. The present invention can improve the anti-interference characteristics and safety of the heading flight transformation process of the aircraft.

[0005] To solve the above technical problem, an embodiment of the present invention provides a heading control method for an aircraft, including:

[0006] S1. Turn off the output of the heading angle control loop of the aircraft in the multi-rotor mode, set the target rate of the heading angle rate control loop to zero, and correct the dynamic heading angle rate error so that the heading angle rate of the aircraft is in a stable state;

[0007] S2. The heading angle control loop of the aircraft includes step S1 during the takeoff process, tilting process, and landing process.

[0008] Preferably, the take-off process and the tilting process include the following steps:

[0009] S11. After receiving the take-off signal, control the aircraft to take off in the multi-rotor mode to reach a preset target altitude;

[0010] S12. Control the aircraft to fly forward at a preset target attitude angle with acceleration;

[0011] S13. When it is detected that the aircraft has flown forward with acceleration to reach a preset airspeed, control the target attitude angle to be in a horizontal state, and at the same time control the front motor to start tilting until the front motor tilts to the horizontal state;

[0012] S14. Control the rear motor to stop running, make the aircraft enter the fixed-wing flight mode, and restart the output of the heading angle control loop to end step S1.

[0013] Preferably, the landing process includes the following steps:

[0014] After receiving the landing signal, control the aircraft to land in the multi-rotor mode until the landing process ends, and end step S1.

[0015] Preferably, the control method further includes:

[0016] When the aircraft reaches the preset target altitude, maintain the multi-rotor mode flight during the process from step S11 to step S13.

[0017] Preferably, both the closing and restarting controls of the output of the heading angle control loop are achieved by setting control parameters.

[0018] Compared with the prior art, the beneficial effect of the embodiment of the present invention is that the present invention provides a heading control method for an aircraft. By turning off the output of the heading angle control loop in the multi-rotor mode, the aircraft does not lock the heading angle of a specified target, which can reduce the control load for correcting the heading angle deviation in the case of crosswinds, and combined with the aerodynamic characteristics of the fixed-wing airframe, the aircraft naturally enters the upwind attitude, thereby improving the anti-interference characteristics and safety of the flight transformation process of the aircraft. At the same time, by setting the target rate of the heading angle rate to zero to correct the dynamic heading angle rate error, when the aircraft is in the upwind direction, it can maintain a stable heading attitude, so as to achieve a relatively stable flight form switch by making full use of the fixed-wing lift in the upwind situation, and further improve the flight stability and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic flowchart of a heading control method for an aircraft in an embodiment of the present invention;

[0020] Figure 2 are the units included in the remote controller in the embodiments of the present invention;

[0021] Figure 3 is a schematic structural diagram of an aircraft in the embodiments of the present invention;

[0022] Among them, the reference numerals in the accompanying drawings of the specification are as follows:

[0023] 1, fixed wing; 2, front motor; 3, rear motor; 4, multi-rotor. Specific embodiments

[0024] As Figure 1 , Figure 2 and Figure 3 shown, a heading control method for an aircraft provided by a preferred embodiment of the present invention includes at least the following steps:

[0025] S1. In the multi-rotor mode, turn off the output of the heading angle control loop of the aircraft, set the target rate of the heading angle rate control loop to zero, and correct the dynamic heading angle rate error so that the heading angle rate of the aircraft is in a stable state;

[0026] S2. The heading angle control loop of the aircraft includes step S1 during the takeoff process, the tilting process, and the landing process.

[0027] The takeoff process and the tilting process include the following steps:

[0028] S11. After receiving the takeoff signal, control the aircraft to take off in the multi-rotor mode to reach a preset target altitude;

[0029] S12. Control the aircraft to tilt forward and accelerate flying at a preset target attitude angle;

[0030] S13. When it is detected that the aircraft accelerates forward to reach a preset airspeed, control the target attitude angle to be in a horizontal state, the aircraft resumes from the tilting state in step S12 to the horizontal state, and at the same time control the front motor to start tilting so that the front motor tilts to the horizontal state;

[0031] S14. Control the rear motor to stop running, so that the aircraft enters the fixed-wing flight mode from the multi-rotor mode, and restart the output of the heading angle control loop to end step S1.

[0032] When the aircraft reaches the preset target altitude, maintain flying in the multi-rotor mode during the process from step S11 to step S13, and turn off the multi-rotor mode after entering the fixed-wing flight mode.

[0033] The landing process includes the following steps:

[0034] After receiving the landing signal, control the aircraft to land in multi-rotor mode. The landing process includes step S1 until the landing process ends, and then end step S1.

[0035] After receiving the takeoff signal, control the front motor 2 and the rear motor 3 of the aircraft to rotate, so that the aircraft takes off vertically in multi-rotor mode to reach the preset target height. Continuously correct the rotation errors of the front motor 2 and the rear motor 3 to keep the aircraft in a dynamically balanced state. During the takeoff process, the target attitude angle of the aircraft is in a horizontal state.

[0036] When the aircraft reaches the preset target height, control the aircraft to tilt at the preset target attitude angle, and control the rotational speeds of the front motor 2 and the rear motor 3, so that the aircraft accelerates forward. At this time, 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 remains unchanged. At this time, the aircraft maintains flight in multi-rotor mode.

[0037] When it is detected that the aircraft reaches the preset airspeed, control the target attitude angle to return to the horizontal state. Within the preset tilt switching time, the aircraft recovers from the tilted state to horizontal flight. Control the front motor 2 to perform a tilting movement through the front tilting servo, so that the front motor 2 tilts to the horizontal state. At this time, the relative position relationship between the front motor 2 and the rear motor 3 is in a vertical state, and the aircraft switches from multi-rotor mode to fixed-wing mode flight, and restart the output of the heading angle control loop, and end step S1.

[0038] During the takeoff process and the tilting process, when in multi-rotor mode, keep the output of the heading angle control loop of the aircraft closed, set the target rate of the heading angle rate control loop to zero, and correct the dynamic heading angle rate error, so that the heading angle rate of the aircraft is in a stable state.

[0039] During the landing process, the aircraft switches from fixed-wing mode to multi-rotor mode, and closes the output of the heading angle control loop again, that is, includes step S1 until the landing process ends, and then end step S1.

[0040] In an embodiment of the present invention, when the aircraft is in the take-off process, the tilting process, and the landing process, by turning off the output of the heading angle control loop in the multi-rotor mode, the aircraft will not be locked at a specified target heading angle, which can reduce the control load for correcting the heading angle deviation in the case of crosswind, and combined with the aerodynamic characteristics of the fixed-wing airframe, the aircraft can naturally enter the upwind attitude and change in the heading direction as the wind direction changes, so that the aircraft maintains the upwind attitude, thereby improving the anti-interference characteristics and safety of the aircraft during the heading flight transformation process. At the same time, by setting the target rate of the heading angle rate control loop to zero and correcting the dynamic heading angle rate error, when the aircraft is in the upwind direction, it can maintain a stable heading attitude, so that the fixed-wing lift in the upwind situation can be fully utilized to achieve a relatively stable flight mode switching, thereby improving the flight stability and safety.

[0041] In an embodiment of the present invention, when the flight action of tilting and switching is completed and the aircraft enters the fixed-wing mode flight, by restarting the output of the heading angle control loop, the aircraft can restore the automatic control of the heading angle, thereby improving the flight stability of the aircraft in the fixed-wing flight mode and further improving the flight safety.

[0042] The closing and restarting controls of the output of the heading angle control loop are both realized by setting control parameters. Turning off the output of the heading angle control loop means that the flight control program of the aircraft does not lock the heading angle control loop of the attitude control loop. Restarting the output of the heading angle control loop means that the flight control program locks the heading angle control loop of the attitude control loop.

[0043] By adopting the upwind flight method, it is easy for the aircraft to obtain a higher airspeed at its own low speed, so that the aircraft can obtain sufficient upward lift.

[0044] During the actual flight process 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 perpendicular involved in the present invention are all dynamic horizontal, dynamic vertical, and dynamic perpendicular.

[0045] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A heading control method for an aircraft, characterized in that, It includes the following steps: S1. Turn off the output of the heading angle control loop of the aircraft in multi-rotor mode, set the target rate of the heading angle rate control loop to zero, and correct the dynamic heading angle rate error so that the heading angle rate of the aircraft is in a stable state; S2. The heading angle control loop of the aircraft includes step S1 during the takeoff process, tilting process, and landing process; The takeoff process and tilting process include the following steps: S11. After receiving the takeoff signal, control the aircraft to take off in multi-rotor mode to reach a preset target altitude; S12. Control the aircraft to fly forward at a preset target attitude angle with acceleration; S13. When it is detected that the aircraft flies forward with acceleration and reaches a preset airspeed, control the target attitude angle to the horizontal state, and at the same time control the front motor to start tilting so that the front motor tilts to the horizontal state; S14. Control the rear motor to stop running, make the aircraft enter the fixed-wing flight mode, and restart the output of the heading angle control loop to end step S1.

2. The heading control method of the aircraft according to claim 1, characterized in that, The landing process includes the following steps: After receiving the landing signal, control the aircraft to land in multi-rotor mode until the landing process ends, and end step S1.

3. The heading control method of the aircraft according to claim 2, characterized in that, The control method further includes: When the aircraft reaches the preset target altitude, maintain the multi-rotor mode flight during the process of steps S11 to S13.

4. The heading control method of the aircraft according to claim 1, characterized in that, The on / off control and restart control of the output of the heading angle control loop are both achieved by setting control parameters.

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