Deceleration method by controlling deflection angle of single rudder

Abstract

The invention discloses a deceleration method by controlling a single rudder deflection angle. The deceleration method comprises the following steps: converting each channel rudder deflection angle output by a guidance law of an aircraft into a single rudder deflection angle corresponding to each control surface of the aircraft; on the basis of the single rudder deflection angle of each control surface, adding a deceleration rudder deflection angle generated by a deceleration channel to obtain an additional deceleration single rudder deflection angle; and calculating a final single rudder deflection angle of each control surface based on the additional deceleration single rudder deflection angle and the single rudder deflection angle of each control surface, and sending the final single rudder deflection angle to a servo mechanism of the aircraft to execute pneumatic control on the control surfaces so as to generate a deceleration effect. According to the method, the effect of the guidance law is not affected while the speed reduction effect is generated, and the capability of accurately controlling the falling speed and the position at the tail section is achieved at the same time.

Description

Technical Field

[0001] This invention relates to the field of aircraft guidance and control, specifically to a deceleration method that controls the deflection angle of a single rudder, applicable to scenarios where aircraft need to precisely control their descent speed. Background Technology

[0002] At the end of their trajectory, aircraft need to maintain both position and landing speed accuracy. This is typically achieved through maneuvering to decelerate and control speed. However, at the end of the trajectory, a conflict inevitably arises between maneuvering deceleration and the guidance law, leading to a sharp drop in position accuracy. In such cases, most aircraft choose to remove the maneuvering at the end to maintain position accuracy, resulting in poor landing speed control accuracy. Finding a way to achieve deceleration without compromising guidance accuracy has been a long-standing challenge. Summary of the Invention

[0003] The purpose of this invention is to provide a deceleration method by controlling the deflection angle of a single rudder, which can achieve deceleration without affecting the guidance law effect and without affecting the position accuracy.

[0004] To achieve the above objectives, the present invention employs the following technical solution: A deceleration method by controlling the deflection angle of a single rudder includes: The deflection angles of each channel output by the aircraft's guidance law are converted into single-piece deflection angles corresponding to each control surface of the aircraft. Based on the single-piece deflection angle of each control surface, the deceleration deflection angle generated by the deceleration channel is added to obtain the additional deceleration single-piece deflection angle; Based on the additional deceleration single-blade deflection angle and the single-blade deflection angle of each control surface, the final single-blade deflection angle of each control surface is calculated and sent to the aircraft's servo mechanism to perform aerodynamic control on the control surfaces to produce a deceleration effect.

[0005] Furthermore, the deflection angles of each channel output by the aircraft's guidance law are converted into single-piece deflection angles corresponding to each control surface of the aircraft. The specific formula is as follows:

[0006]

[0007] in, These are the roll channel rudder deflection, yaw channel rudder deflection, and pitch channel rudder deflection outputs of the aircraft's control law; , , , These are the deflection angles of individual control surfaces 1, 2, 3, and 4 of the aircraft.

[0008] Furthermore, the aircraft is an axisymmetric aircraft with four axisymmetrically distributed control surfaces; the X-axis of the aircraft coordinate system is along the aircraft axis and corresponds to the roll channel; the Y-axis and Z-axis are located in a plane perpendicular to the aircraft axis and are perpendicular to each other, corresponding to the yaw channel and pitch channel, respectively.

[0009] Furthermore, the deceleration channel is constructed to determine the deceleration rudder deflection angle; the aircraft's control law obtains the nominal speed and the aircraft's current speed, and the difference between the two is multiplied by a speed control gain to obtain the deceleration rudder deflection angle of the deceleration channel.

[0010] Furthermore, the nominal speed is derived from the nominal trajectory of the aircraft, which is the ideal trajectory of the aircraft obtained through prior simulation.

[0011] Furthermore, the additional deceleration single-blade deflection angles of the four control surfaces of the aircraft should meet the following requirements:

[0012] in , , , These are the additional deceleration single-plate rudder deflection angles for rudder surfaces 1, 2, 3, and 4, respectively. This refers to the deceleration rudder deflection angle.

[0013] Furthermore, based on the additional deceleration single-blade deflection angle and the single-blade deflection angle of each control surface, the final single-blade deflection angle of each control surface is calculated, including:

[0014] in , , , These are the final single-piece rudder deflection angles for rudder surfaces 1, 2, 3, and 4, respectively.

[0015] A terminal device includes a processor, a memory, and a computer program stored in the memory; when the processor executes the computer program, it implements the deceleration method by controlling the deflection angle of a single-chip rudder.

[0016] A computer-readable storage medium storing a computer program; when executed by a processor, the computer program implements the deceleration method by controlling the deflection angle of a single-chip rudder.

[0017] Compared with the prior art, the present invention has the following technical features: This invention proposes the idea of ​​generating additional drag to reduce speed by adding additional rudder deflection angle. The added additional single-blade deflection angle will not generate pitch, yaw channel forces and moments, nor will it generate roll moment. It only increases the axial drag of the aircraft. While generating a deceleration effect, it does not affect the effect of the guidance law, that is, it has the ability to simultaneously complete the precise control of the descent speed and position in the terminal phase. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of the method of the present invention; Figure 2 This is a diagram of the control force generated from the tail of the aircraft in one embodiment of the present invention; Figure 3 This is a curve showing the deceleration effect of an additional single-blade deflection angle in one embodiment of the present invention. Detailed Implementation

[0019] This invention proposes a deceleration method by controlling the deflection angle of a single rudder. This method adds a deceleration rudder deflection angle to the single rudder deflection angle that satisfies the guidance law. The pitch, yaw, and channel forces and moments generated by the additional rudder deflection angles of the four rudders cancel each other out, as do the roll moments. The axial drag generated by the additional rudder deflection angles of the four rudders is superimposed. This generates additional drag to achieve deceleration without affecting terminal guidance accuracy. Simulation analysis demonstrates the effectiveness of this invention.

[0020] See Figure 1 The specific steps of this invention are as follows: Step 1: Convert the rudder deflection angles of each channel output by the aircraft's guidance law into single-piece rudder deflection angles corresponding to each control surface of the aircraft, as follows: The conversion formulas for the mutual assembly of single-piece rudders and channel rudders are shown below:

[0021]

[0022] in, These are the roll channel rudder deflection, yaw channel rudder deflection, and pitch channel rudder deflection outputs of the aircraft's control law; see also Figure 2 The aircraft in this invention is an axisymmetric aircraft with four axisymmetrically distributed control surfaces; the X-axis of the aircraft coordinate system is defined as being along the aircraft axis, and the Y-axis and Z-axis are located in planes perpendicular to the aircraft axis and are perpendicular to each other. Figure 2 In the example, within the YOZ plane, control surfaces 1, 2, 3, and 4 are located in the first to fourth quadrants, respectively; , , , These are the deflection angles of single rudder surfaces 1, 2, 3, and 4, respectively. The positive deflection angle of a single rudder surface is in the counterclockwise direction.

[0023] Step 2: Based on the single-piece deflection angle of each control surface, add the deceleration deflection angle generated by the deceleration channel to obtain the additional deceleration single-piece deflection angle.

[0024] In this design, a deceleration channel is incorporated based on the roll channel rudder deflection, yaw channel rudder deflection, and pitch channel rudder deflection to determine the deceleration rudder deflection angle. The aircraft's control law obtains the nominal speed and the aircraft's current speed, subtracts the two, and multiplies the result by a preset speed control gain to obtain the deceleration rudder deflection angle of the deceleration channel. This deceleration rudder deflection angle can only be a positive value. The nominal speed is derived from the aircraft's nominal trajectory, which is an ideal trajectory of the aircraft obtained through pre-simulation, containing information such as the direction and nominal speed at various positions of the aircraft.

[0025] To ensure that no pitch or yaw forces and moments are generated, and no roll moments are produced, while only increasing aircraft drag, the additional deceleration single-blade deflection angles of the four control surfaces in this design should meet the following requirements:

[0026] in , , , These are the additional deceleration single-blade deflection angles for rudder surfaces 1, 2, 3, and 4, respectively.

[0027] The direction of the control force, viewed from the tail of the aircraft, is as follows: Figure 2 As shown in the figure, the additional torque of the three channels is 0, and the additional pitch and yaw forces are 0. In this scheme, before the addition of a single-blade deflection angle, in the XOY plane, all four control surfaces are defined with the counterclockwise direction as the positive deflection direction (i.e., the direction when the single-blade deflection angle is positive). Figure 2 As shown, after adding the deceleration single-blade deflection angle, since the value is positive, the rudder surfaces 1 and 3 are still counterclockwise, while the rudder surfaces 2 and 4 become clockwise.

[0028] Step 3: Based on the additional deceleration single-blade deflection angle and the single-blade deflection angle of each control surface, calculate the final single-blade deflection angle of each control surface and send it to the aircraft's servo mechanism to perform aerodynamic control on the control surfaces to produce a deceleration effect.

[0029] The final deflection angle of a single rudder piece is calculated as follows:

[0030] in , , , These are the final single-piece rudder deflection angles for rudder surfaces 1, 2, 3, and 4, respectively.

[0031] The reason it does not affect the guidance effect is that this invention does not change the channel rudder deflection angle, as shown below:

[0032] Example: In this embodiment, mathematical simulations were performed 6km from the end of the trajectory of an aircraft, with simulations using no deceleration plus a single-blade rudder deflection angle, with a 5° deceleration plus a single-blade rudder deflection angle, and with a 10° deceleration plus a single-blade rudder deflection angle. The terminal velocities were 733.92m / s, 723.41m / s, and 689.19m / s, respectively. Figure 3 As shown in the image, the deceleration effect is obvious.

[0033] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A deceleration method by controlling the deflection angle of a single rudder, characterized in that, include: The deflection angles of each channel output by the aircraft's guidance law are converted into single-piece deflection angles corresponding to each control surface of the aircraft. Based on the single-piece deflection angle of each control surface, the deceleration deflection angle generated by the deceleration channel is added to obtain the additional deceleration single-piece deflection angle; Based on the additional deceleration single-blade deflection angle and the single-blade deflection angle of each control surface, the final single-blade deflection angle of each control surface is calculated and sent to the aircraft's servo mechanism to perform aerodynamic control on the control surfaces to produce a deceleration effect.

2. The deceleration method by controlling the deflection angle of a single rudder according to claim 1, characterized in that, The deflection angles of each channel output by the aircraft's guidance law are converted into single-piece deflection angles corresponding to each control surface of the aircraft. The specific formula is as follows: in, These are the roll channel rudder deflection, yaw channel rudder deflection, and pitch channel rudder deflection outputs of the aircraft's control law; , , , These are the deflection angles of individual control surfaces 1, 2, 3, and 4 of the aircraft.

3. The deceleration method by controlling the deflection angle of a single rudder according to claim 1, characterized in that, The aircraft is an axisymmetric aircraft with four axisymmetrically distributed control surfaces; the X-axis of the aircraft coordinate system is along the aircraft axis and corresponds to the roll channel; the Y-axis and Z-axis are located in a plane perpendicular to the aircraft axis and are perpendicular to each other, corresponding to the yaw channel and pitch channel, respectively.

4. The deceleration method by controlling the deflection angle of a single rudder according to claim 1, characterized in that, The deceleration path is constructed to determine the deceleration rudder deflection angle; the aircraft's control law obtains the nominal speed and the aircraft's current speed, and the difference between the two is multiplied by a speed control gain to obtain the deceleration rudder deflection angle of the deceleration path.

5. The deceleration method by controlling the deflection angle of a single rudder according to claim 4, characterized in that, The nominal speed is derived from the nominal trajectory of the aircraft, which is the ideal trajectory of the aircraft obtained through prior simulation.

6. The deceleration method by controlling the deflection angle of a single rudder according to claim 1, characterized in that, The additional deceleration single-blade deflection angle of the four control surfaces of the aircraft should meet the following requirements: in , , , These are the additional deceleration single-plate rudder deflection angles for rudder surfaces 1, 2, 3, and 4, respectively. This refers to the deceleration rudder deflection angle.

7. The deceleration method by controlling the deflection angle of a single rudder according to claim 1, characterized in that, Based on the additional deceleration single-plate rudder deflection angle and the single-plate rudder deflection angle of each rudder surface, the final single-plate rudder deflection angle of each rudder surface is calculated, including: in , , , These are the final single-piece rudder deflection angles for rudder surfaces 1, 2, 3, and 4, respectively.

8. A terminal device, comprising a processor, a memory, and a computer program stored in the memory; characterized in that, When the processor executes the computer program, it implements the deceleration method by controlling the deflection angle of a single rudder as described in any one of claims 1-7.

9. A computer-readable storage medium storing a computer program; characterized in that, When the computer program is executed by the processor, it implements the deceleration method by controlling the deflection angle of a single rudder as described in any one of claims 1-7.

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