Rolling Aircraft Control Method Based on Online Compensation of Isolation Degree

Abstract

The present invention discloses a control method for a rolling aircraft based on online isolation compensation. In this method, a stable convergence value is obtained through continuous calculation, and then the disturbance angular acceleration caused by the disturbance torque is obtained. On this basis, the line-of-sight angular velocity output by the platform seeker is compensated in real time to obtain a more accurate target line-of-sight angular velocity, and an overload command is generated accordingly.

Description

Technical Field

[0001] The present invention relates to the field of aircraft guidance and control, and particularly to a control method for a rolling aircraft based on online compensation of isolation degree. Background Art

[0002] In engineering practice, the common structure of the seeker of a rolling aircraft is a platform seeker, whose function is to ensure the stability of the seeker optical axis in space and complete the search, capture and tracking of the target. In the single-channel control loop of the actual platform seeker system, there are an electromotive force loop, a disturbance torque loop, a stabilization loop and a tracking loop. The electromotive force loop is generated due to the electromagnetic effect. During the rotation of the motor, the rotor cuts the magnetic field lines, generating an electromotive force opposite to the motor drive voltage. The disturbance torque loop is caused by wire pulling and friction during the rotation of the platform seeker. The stabilization loop, as the inner loop of the tracking loop, functions to isolate the angular disturbance of the aircraft, stabilize the pointing of the seeker optical axis and improve the characteristics of the tracking system. The function of the tracking loop is to control the movement of the seeker optical axis according to the target position error information given by the shooter or the image tracker in the manual or automatic tracking mode to achieve real-time tracking of the target.

[0003] During the flight of the rolling aircraft, the attitude disturbance of the aircraft will be partially coupled into the seeker, resulting in an error in the output target line-of-sight angular velocity, reducing the stability and guidance accuracy of the guidance system. The main factor causing the isolation degree of the rolling aircraft seeker is the disturbance torque loop, and there is currently no targeted solution for online compensation of the isolation degree brought by the disturbance torque loop of the rolling aircraft.

[0004] For the above reasons, the inventor of the present invention has conducted in-depth research on the existing guidance and control methods, expecting to design a new control method for a rolling aircraft based on online compensation of isolation degree that can solve the above problems. Summary of the Invention

[0005] To overcome the above problems, the inventor of the present invention has conducted intensive research and designed a control method for a rolling aircraft based on online compensation of isolation degree. In this method, a stable convergence value is obtained through continuous calculation, and then the disturbance angular acceleration caused by the disturbance torque is obtained. On this basis, the line-of-sight angular velocity output by the platform seeker is compensated in real time to obtain a more accurate target line-of-sight angular velocity, and an overload command is generated accordingly, thus completing the present invention.

[0006] Specifically, the purpose of the present invention is to provide a control method for a rolling aircraft based on online compensation of isolation degree. In the terminal guidance section of the aircraft, the method includes the following steps:

[0007] Step 1, irradiate the target by emitting irradiation laser through an unmanned aerial vehicle.

[0008] Step 2: Receive the laser signal diffusely reflected by the target through the laser seeker on the aircraft, and then obtain the measured target line-of-sight angular velocity information.

[0009] Step 3: Correct the measured target line-of-sight angular velocity information by the compensation isolation degree to obtain accurate target line-of-sight angular velocity information.

[0010] Step 4: Control the aircraft based on the accurate target line-of-sight angular velocity information through the proportional navigation guidance law.

[0011] Among them, step 3 includes sub-step 1: After entering the terminal guidance section, obtain the interference angular acceleration in real time through the following formula (1):

[0012]

[0013] z0, z1, z2, v0, and v1 are all intermediate variables. represents the derivative of z0. represents the derivative of z1. represents the derivative of z2.

[0014] y represents the input quantity.

[0015] U Δ represents the armature voltage measured in real time.

[0016] K2 represents the gain of the stable loop amplifier.

[0017] K T represents the torque constant.

[0018] J represents the moment of inertia of the motor.

[0019] R represents the resistance of the armature winding.

[0020] X1 represents the state quantity of the spatial angle of the optical axis of the platform seeker.

[0021] λ0, λ1, λ2, and L all represent the designed gain values.

[0022] Among them, in step 3, read the measured armature voltage in real time, and then solve formula (1) to obtain z0, z1, z2, v0, and v1. When the obtained z1 converges stably, the calculation stops.

[0023] Among them, the fixed value to which it converges stably is -e.

[0024] Among them, when the z1 value obtained by the (k + 1)-th calculation and the z1 value obtained by the k-th calculation satisfy then z1 converges stably.

[0025] Preferably, when z1 converges stably, select

[0026] Among them, step 3 includes sub-step 2, and the additional line-of-sight angular velocity caused by the interference angular acceleration e is obtained in real time through the following formula (II)

[0027]

[0028] Among them, represents the additional line-of-sight angular velocity,

[0029] K1 represents the tracking loop amplifier gain,

[0030] K2 represents the stabilizing loop amplifier gain,

[0031] K T represents the torque constant,

[0032] k g represents the voltage scale factor of the rate gyro,

[0033] J represents the moment of inertia of the motor,

[0034] R represents the resistance of the armature winding,

[0035] s represents a variable in the complex domain.

[0036] Among them, step 3 includes sub-step 3, and the accurate target line-of-sight angular velocity information is obtained in real time through the following formula (III)

[0037]

[0038] Among them, represents the accurate target line-of-sight angular velocity, represents the measured target line-of-sight angular velocity.

[0039] Among them, in step 4, the overload command is obtained in real time through the following formula (IV), and then the aircraft is controlled accordingly:

[0040]

[0041] Among them, a c represents the overload command, N is the proportionality coefficient, V c represents the relative velocity between the aircraft and the target.

[0042] In the roll aircraft control method based on online compensation of isolation degree according to the present invention, when entering the terminal guidance section, the additional line-of-sight angular velocity caused by the interference angular acceleration is obtained, and based on this, the line-of-sight angular velocity output by the platform seeker is compensated, so as to obtain a more accurate line-of-sight angular velocity, which is convenient for more accurate guidance control commands. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Fig. shows the overall scheme logic diagram of the roll aircraft control method based on online compensation of isolation degree according to a preferred embodiment of the present invention;

[0044] Figure 2 Fig. shows the comparison diagram of the line-of-sight angular velocity before and after compensation in Experimental Example 1 of the present invention;

[0045] Figure 3 Fig. shows Figure 2 magnified view of;

[0046] Figure 4 Fig. shows the movement trajectory diagram of the aircraft and the target in Experimental Example 2 of the present invention;

[0047] Figure 5 Fig. shows Figure 4 magnified view of. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0048] The present invention will be further described in detail below with reference to the drawings and embodiments. Through these descriptions, the features and advantages of the present invention will become clearer and more definite.

[0049] The special term "exemplary" here means "serving as an example, embodiment or illustration". Any embodiment described as "exemplary" here does not have to be construed as superior to or better than other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings do not have to be drawn to scale unless otherwise specified.

[0050] According to the roll aircraft control method based on online compensation of isolation degree provided by the present invention, as shown in Figure 1 , in the terminal guidance section of the aircraft, the method includes the following steps:

[0051] Step 1, irradiate the target by emitting irradiation laser through the UAV,

[0052] Step 2, receive the laser signal diffusely reflected by the target through the laser seeker on the aircraft, and then obtain the measured target line-of-sight angular velocity information,

[0053] Step 3, correct the measured target line-of-sight angular velocity information by compensating the isolation degree to obtain accurate target line-of-sight angular velocity information,

[0054] Step 4: Based on the accurate target line-of-sight angular velocity information, control the aircraft using the proportional guidance law.

[0055] In the present application, after the launch, the aircraft first flies obliquely upwards, at which time the aircraft is in an uncontrolled state. When it reaches the highest point, the aircraft enters the intermediate guidance section, and the onboard equipment on the aircraft is powered on and working, including the satellite receiving device on the aircraft, which is also powered on and working, and can obtain the aircraft's own speed and position information in real time; when the distance between the aircraft and the target reaches a certain range, the fairing of the laser guidance head on the aircraft falls off, exposing the laser guidance head, and the laser guidance head begins to receive reflected laser. At this time, the aircraft enters the terminal guidance section, and the aircraft is controlled according to the overload command.

[0056] In the present application, before the aircraft is launched, the UAV is controlled to fly toward the target area and hover above the target area. After the aircraft is launched, the ground control station sends the specific time information of the aircraft launch to the UAV. The UAV obtains the flight time of the aircraft and the time of entering the terminal guidance stage according to the speed of the aircraft and the distance between the launch point and the target. About two seconds before the aircraft enters the terminal guidance stage, a laser is fired to illuminate the target, so that the seeker on the aircraft can capture the diffusely reflected laser signal and locate the target.

[0057] In a preferred embodiment, step 3 includes sub-step 1, after entering the final guidance section, obtaining the interference angular acceleration in real time by the following formula (1); that is, the armature voltage is measured immediately when entering the guidance section, and sub-step 1 is performed accordingly;

[0058]

[0059] z0, z1, z2, v0 and v1 are all intermediate variables and have no specific physical meaning. represents the derivative of z0, represents the derivative of z1, represents the derivative of z2;

[0060] sgn represents the sign function, that is

[0061] y represents the input amount,

[0062] U Δ Represents the armature voltage measured in real time,

[0063] K2 represents the stable loop amplifier gain, preferably K2=123,

[0064] K T Represents the torque constant, preferably K T =0.2344N·m·A-1 ,

[0065] J represents the moment of inertia of the motor, preferably taking the value of J = 0.002 kg·m 2 ,

[0066] R represents the resistance of the armature winding, preferably taking the value of R = 8 Ω;

[0067] λ0, λ1, λ2 and L all represent the designed gain values; preferably taking the values of λ0 = 10, λ1 = 14, λ2 = 19, L = 4.

[0068] X1 represents the state quantity of the spatial angle of the optical axis of the platform seeker; it is obtained by integrating the spatial angular velocity of the optical axis of the platform seeker output by the angular rate gyro in real time and is a known quantity in the calculation process of this application.

[0069] In a preferred embodiment, in step 3, the measured armature voltage is read in real time, and then z0, z1, z2, v0 and v1 are obtained by solving formula (1); preferably, the armature voltage is read 20 times per second and 20 calculations are performed until the calculation stops;

[0070] When the obtained z1 converges stably, the calculation stops,

[0071] where the fixed value to which it converges stably is -e, that is, the stable convergence value of z1 is equal to the negative value of the disturbance angular acceleration.

[0072] In a preferred embodiment, when the z1 value obtained from the (k + 1)-th calculation and the z1 value obtained from the k-th calculation satisfy , z1 converges stably;

[0073] Preferably, when z1 converges stably, select

[0074] In a preferred embodiment, step 3 includes sub-step 2, and the additional line-of-sight angular velocity caused by the disturbance angular acceleration e is obtained in real time through the following formula (2)

[0075] where, represents the additional line-of-sight angular velocity,

[0076] K1 represents the gain of the tracking loop amplifier,

[0077] K2 represents the gain of the stabilizing loop amplifier,

[0078] K T represents the torque constant,

[0079] k g represents the voltage scale factor of the rate gyro

[0080] J represents the moment of inertia of the motor

[0081] R represents the resistance of the armature winding

[0082] s represents a variable in the complex domain, which is the independent variable of the transfer function shown in Equation (2). If the variable s in the complex domain is replaced by the differential operator d / dt in the time domain, Equation (2) changes from a transfer function to a differential equation. If the variable s in the complex domain is replaced by the operator jω, Equation (2) changes from a transfer function to a frequency characteristic

[0083] In a preferred embodiment, step 3 includes sub-step 3, in which accurate target line-of-sight angular velocity information is obtained in real time through the following Equation (3)

[0084]

[0085] where represents the accurate target line-of-sight angular velocity represents the measured target line-of-sight angular velocity. That is, the error of the target line-of-sight angular velocity caused by the isolation degree is cancelled by subtraction

[0086] In a preferred embodiment, in step 4, an overload command is obtained in real time through the following Equation (4), and then the aircraft is controlled accordingly

[0087]

[0088] where a c represents the overload command, N is the proportionality coefficient, and its value is preferably 4. V c represents the relative velocity between the aircraft and the target, which is obtained in real time through the satellite receiving device. The overload command is sent to the servo system on the aircraft, and the servo system controls the servo to deflect the rudder accordingly to adjust the attitude of the aircraft, so that the aircraft flies towards the target

[0089] Experimental Example 1

[0090] Set the disturbance angular acceleration e to a sinusoidal disturbance signal with an amplitude A = 1.5° / s 2 , a frequency ω = 1 rad / s, K1 = 14, K2 = 123, k g = 1, R = 8 Ω, K T = 0.2344 N·m·A -1 , J = 0.002 kg·m 2 .

[0091] Compensate the seeker line-of-sight angular velocity using Equation (1), Equation (2) and Equation (3)

[0092]

[0093] z0, z1, z2, v0, and v1 are all intermediate variables and have no specific physical meaning. represents the derivative of z0. represents the derivative of z1. represents the derivative of z2.

[0094] y represents the input quantity.

[0095] U Δ represents the armature voltage obtained by real-time measurement. In the experiment, a module is built through Matlab / Simulink for simulation, that is, U Δ 's measured value is given in real time by the module.

[0096] λ0 = 10, λ1 = 14, λ2 = 19, L = 4.

[0097] The formula (I) is calculated continuously for multiple times. When the obtained z1 converges stably, the fixed value it converges to stably is -e.

[0098]

[0099]

[0100] The simulation results are as Figure 2 shown. Among them, the dashed line represents the line-of-sight angular velocity before compensation, that is The solid line represents the line-of-sight angular velocity after compensation, that is Figure 3 represents Figure 2 's enlarged view. From Figure 2 , Figure 3 it can be known that: the amplitude of the change in the line-of-sight angular velocity of the seeker caused by the disturbance angular acceleration caused by the disturbance torque is about 0.068° / s, and the amplitude of the change in the line-of-sight angular velocity of the seeker after compensation is 0.0001° / s. Therefore, the compensation scheme greatly suppresses the influence of the isolation degree on the line-of-sight angular velocity of the seeker.

[0101] Furthermore, since e is set as the above-known sine signal during simulation, e is estimated according to formula (I), and then caused by e is solved according to formula (II) and compensated according to formula (III). By comparing the line-of-sight angular velocity before and after compensation through the output graph, that is Figure 2 shown, the line-of-sight angular velocity after compensation is approximately 0. Therefore, it can be shown that the above algorithm has high reliability and can accurately estimate the disturbance angular acceleration e and eliminate the additional line-of-sight angular velocity caused by the disturbance angular acceleration e.

[0102] Experimental Example 2:

[0103] Set the target as a ground target with variable speed, and its motion trajectory is as shown by the solid line in Figure 4 and Figure 5 The launch vehicle flies towards the target, and the vehicle is controlled by a roll vehicle control method based on online compensation of isolation. Specifically, it includes the following steps:

[0104] Step 1: The UAV emits irradiation laser to irradiate the target.

[0105] Step 2: The laser seeker on the vehicle receives the laser signal diffusely reflected by the target, and then obtains the measured target line-of-sight angular velocity information.

[0106] Step 3: Correct the measured target line-of-sight angular velocity information by compensating the isolation to obtain accurate target line-of-sight angular velocity information.

[0107] Step 4: Based on the accurate target line-of-sight angular velocity information, control the vehicle through the proportional navigation guidance law.

[0108] Among them, the UAV emits laser two seconds before the vehicle enters the terminal guidance section and is discovered by the target, and the target immediately adjusts its traveling direction.

[0109] The seeker on the vehicle captures the laser signal diffusely reflected at the target after entering the terminal guidance section, and obtains the measured target line-of-sight angular velocity accordingly.

[0110] On the vehicle, after entering the terminal guidance section, the interference angular acceleration is obtained through the following formula (I).

[0111]

[0112]

[0113] λ0 = 10, λ1 = 14, λ2 = 19, L = 4, K2 = 123, K T = 0.2344 N·m·A -1 , J = 0.002 kg·m 2 , R = 8 Ω, U Δ represents the armature voltage measured in real time.

[0114] Read the armature voltage 20 times per second and perform 20 times of calculations until the obtained z1 converges stably; the stable convergence fixed value is -e, that is, the stable convergence value is equal to the negative value of the interference angular acceleration.

[0115] Obtain the additional line-of-sight angular velocity caused by the interference angular acceleration e through the following formula (II).

[0116]

[0117] K2 = 123, K T = 0.2344 N·m·A -1 , J = 0.002 kg·m 2 , R = 8 Ω, k g = 1, K1 = 14, s is a variable in the complex number field;

[0118] Then obtain the accurate target line-of-sight angular velocity through the following formula (III);

[0119]

[0120] Finally, obtain the overload command through the following formula (IV):

[0121]

[0122] Control the aircraft according to the overload command, and the obtained aircraft trajectory is as shown by the dashed line in Figure 4 and Figure 5 ;

[0123] According to Figure 4 and Figure 5 it can be known that even if the target changes its traveling direction midway, the aircraft still hits the target finally.

[0124] The above has described the present invention in combination with preferred embodiments, but these embodiments are only exemplary and only play an illustrative role. On this basis, various substitutions and improvements can be made to the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A control method for a rolling aircraft based on online compensation of isolation degree, characterized in that, The method comprises the following steps: Step 1: irradiate the target by emitting irradiation laser through a drone; Step 2: receive the laser signal diffusely reflected by the target through the laser seeker on the aircraft, and then obtain the measured target line-of-sight angular velocity information; Step 3: correct the measured target line-of-sight angular velocity information by compensation isolation to obtain accurate target line-of-sight angular velocity information; Step 4: control the aircraft based on the accurate target line-of-sight angular velocity information through the proportional navigation guidance law; Sub-step 1 is included in Step 3: after entering the terminal guidance section, obtain the interference angular acceleration in real time through the following formula (1); z0, z1, z2, v0, and v1 are all intermediate variables, represents the derivative of z0, represents the derivative of z1, represents the derivative of z2; y represents the input quantity, U Δ represents the armature voltage obtained by real-time measurement, K2 represents the gain of the stable loop amplifier; K T represents the torque constant J represents the moment of inertia of the motor; R represents the resistance of the armature winding; X1 represents the state variable of the space angle of the optical axis of the platform seeker; λ0, λ1, λ2 and L all represent the designed gain values; In Step 3, read the measured armature voltage in real time, and then solve formula (1) to obtain z0, z1, z2, v0 and v1. When the obtained z1 converges stably, the calculation stops; wherein, the fixed value to which it converges stably is -e; When the z1 value obtained from the (k + 1)-th calculation and the z1 value obtained from the k-th calculation satisfy then z1 converges stably; When z1 converges stably, select 2. The control method for a rolling aircraft based on online compensation of isolation degree according to claim 1, characterized in that, Sub-step 2 is included in Step 3, and the additional line-of-sight angular velocity caused by the interference angular acceleration e is obtained in real time by the following formula (II). Among them, represents the additional line-of-sight angular velocity, K1 represents the gain of the tracking loop amplifier; K2 represents the gain of the stable loop amplifier; K T represents the torque constant k g represents the voltage scale factor of the rate gyro J represents the moment of inertia of the motor; R represents the resistance of the armature winding; s represents a variable in the complex domain.

3. The control method for a rolling aircraft based on online compensation of isolation degree according to claim 1, characterized in that, Sub-step 3 is included in Step 3: obtain the accurate target line-of-sight angular velocity information in real time through the following formula (3); Among them, represents the accurate target line-of-sight angular velocity, represents the measured target line-of-sight angular velocity, represents the additional line-of-sight angular velocity.

4. The roll aircraft control method based on online isolation compensation according to claim 1, characterized in that In Step 4, obtain the overload command in real time through the following formula (4), and then control the aircraft accordingly: Among them, a c represents an overload instruction, N is a proportionality coefficient, and V c represents the relative velocity between the aircraft and the target.

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