An unmanned aerial vehicle landing guidance method using photoelectric guidance interference compensation

Abstract

The present application relates to a UAV landing guidance method using photoelectric guidance interference compensation, which provides a method for measuring the pitch and azimuth information and distance information of a UAV by an infrared thermal imager and a laser range finder of a photoelectric guidance system on a ship, and calculating the vertical and lateral approximate deviation signals; then, according to the pitch and azimuth signals, nonlinear transformation and integration and speed and acceleration filtering processing are carried out, respectively, to obtain the pitch and azimuth nonlinear transformation, integration, angular velocity filtering and angular acceleration filtering estimation signals, and combine to form the pitch and azimuth comprehensive signals, then an adaptive algorithm is used to estimate and compensate the interference in the landing process from the position, damping and angle three aspects, and finally the pitch and azimuth attitude angle expected signals are formed and sent to the UAV attitude angle stabilization system, so that the stable control of photoelectric guidance landing is realized. The scheme has the advantages of simple measurement, good landing control precision and effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of unmanned aerial vehicle position control, in particular to an unmanned aerial vehicle landing control and guiding method using photoelectric guidance. BACKGROUND

[0002] The landing or carrier landing process of unmanned aerial vehicle is a very complex process, both of which have the same technology, and the carrier landing guiding is equivalent to a special case of landing guiding. The landing area is limited, and the landing platform has a sway effect. Therefore, the technical method of the present application for landing guiding can also be applied to carrier landing, which has a wide application in the field of military and civilian unmanned aerial vehicles. The landing and carrier landing control of unmanned aerial vehicle has autonomous landing and optical auxiliary landing two ways. With the development of technology, the "precise approach landing and carrier landing" guidance using precise data as guiding information has become a development trend of unmanned aerial vehicle guiding system. The photoelectric guiding system works in optical frequency, has high measurement accuracy, strong anti-electronic interference ability, high-resolution imaging ability, and good adaptability. In the guiding process, the photoelectric guiding system is introduced to form a new type of carrier landing guiding system with multiple guiding means matching, complementary coexistence, which has become a development trend. Based on the above background reasons, the present application proposes an unmanned aerial vehicle landing method based on photoelectric guidance system auxiliary measurement and guiding with interference compensation, which has high landing precision and quality, and high engineering application value.

[0003] It should be noted that the information in the above background section of the invention is only used to strengthen the understanding of the background of the invention, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0004] The purpose of the present application is to provide an unmanned aerial vehicle landing guiding method using photoelectric guidance interference compensation, thereby overcoming the problem of insufficient stability and precision of unmanned aerial vehicle landing caused by the limitations and defects of related technology.

[0005] According to one aspect of the present application, an unmanned aerial vehicle landing guiding method using photoelectric guidance interference compensation is provided, which includes the following five steps:

[0006] Step S10, the infrared thermal imager of the photoelectric guiding system on the landing field measures the pitch signal and azimuth signal of the unmanned aerial vehicle, and the laser range finder of the photoelectric guiding system on the landing field measures the distance information of the unmanned aerial vehicle from the carrier landing point; and calculates the vertical approximate deviation signal of the unmanned aerial vehicle according to the distance information of the unmanned aerial vehicle from the carrier landing point and the pitch signal of the unmanned aerial vehicle; calculates the lateral approximate deviation signal of the unmanned aerial vehicle according to the distance information of the unmanned aerial vehicle from the carrier landing point and the azimuth signal of the unmanned aerial vehicle.

[0007] Step S20, according to the pitch signal of the unmanned aerial vehicle, nonlinear transformation is carried out to obtain a pitch nonlinear signal; then the pitch signal and the pitch nonlinear signal are combined and integrated to obtain a pitch nonlinear integral signal; according to the azimuth signal of the unmanned aerial vehicle, nonlinear transformation is carried out to obtain an azimuth nonlinear signal; then the azimuth signal and the azimuth nonlinear signal are combined and integrated to obtain an azimuth nonlinear integral signal.

[0008] Step S30, according to the pitch signal of the unmanned aerial vehicle, first, an angular velocity estimation filter is designed to obtain a pitch angular velocity estimation filter signal; then an angular acceleration estimation filter is designed to obtain a pitch angular acceleration estimation filter signal; and the two are superimposed to obtain a pitch damping combined signal; then, according to the azimuth signal of the unmanned aerial vehicle, first, an angular velocity estimation filter is designed to obtain an azimuth angular velocity estimation filter signal; then an angular acceleration estimation filter is designed to obtain an azimuth angular acceleration estimation filter signal; and the two are superimposed to obtain an azimuth damping combined signal.

[0009] Step S40, according to the pitch signal, the pitch nonlinear signal, the pitch nonlinear integral signal, the pitch angular acceleration estimation filter signal and the pitch angular velocity estimation filter signal of the unmanned aerial vehicle, linear combination is carried out to obtain a pitch comprehensive signal; then, according to the pitch comprehensive signal, a pitch interference compensation adaptive law, a pitch interference nonlinear compensation adaptive law, a pitch damping interference compensation adaptive law and a pitch position interference compensation adaptive law are designed; and through integration, a pitch interference compensation coefficient, a pitch interference nonlinear compensation coefficient, a pitch damping interference compensation coefficient and a pitch position interference compensation coefficient are obtained; and combination is carried out to obtain a pitch interference compensation comprehensive signal; then, the pitch comprehensive signal and a pitch comprehensive nonlinear transformation signal are superimposed to form an unmanned aerial vehicle pitch photoelectric guidance signal, which is sent to the unmanned aerial vehicle pitch angle tracking system to realize vertical automatic landing of the unmanned aerial vehicle.

[0010] Step S50, according to the azimuth signal, the azimuth nonlinear signal, the azimuth nonlinear integral signal, the azimuth angular acceleration estimation filter signal and the azimuth angular velocity estimation filter signal, linear combination is carried out to obtain an azimuth comprehensive signal; then, according to the azimuth comprehensive signal, an azimuth interference compensation adaptive law, an azimuth interference nonlinear compensation adaptive law, an azimuth damping interference compensation adaptive law and an azimuth position interference compensation adaptive law are designed; and through integration, an azimuth interference compensation coefficient, an azimuth interference nonlinear compensation coefficient, an azimuth damping interference compensation coefficient and an azimuth position interference compensation coefficient are obtained; and combination is carried out to obtain an azimuth interference compensation comprehensive signal; then, the azimuth comprehensive signal and the pitch comprehensive nonlinear transformation signal are superimposed to form an unmanned aerial vehicle azimuth photoelectric guidance signal, which is sent to the unmanned aerial vehicle azimuth angle tracking system to realize lateral automatic landing of the unmanned aerial vehicle.

[0011] In an example embodiment of the present application, the vertical approximate deviation signal of the UAV is calculated according to the distance information of the UAV from the landing point and the pitch signal of the UAV; the lateral approximate deviation signal of the UAV is calculated according to the distance information of the UAV from the landing point and the azimuth signal of the UAV, including:

[0012] y a =r sin(θ1);

[0013] z a =r sin(θ2);

[0014] θ1 is the pitch signal of the UAV measured by the infrared thermal imager of the photoelectric guidance system, θ2 is the azimuth signal of the UAV measured by the infrared thermal imager of the photoelectric guidance system, r is the distance information of the UAV from the landing point measured by the laser range finder of the photoelectric guidance system on the landing field, y a is the vertical approximate deviation signal of the UAV; z a is the lateral approximate deviation signal of the UAV.

[0015] In an example embodiment of the present application, the pitch nonlinear signal is obtained by performing nonlinear transformation on the pitch signal of the UAV; then the pitch nonlinear integral signal is obtained by combining and integrating the pitch signal of the UAV and the pitch nonlinear signal; the azimuth nonlinear signal is obtained by performing nonlinear transformation on the azimuth signal of the UAV; then the azimuth nonlinear integral signal is obtained by combining and integrating the azimuth signal of the UAV and the azimuth nonlinear signal, including:

[0016]

[0017] Wherein q1 is the pitch nonlinear signal; s1 is the pitch nonlinear integral signal; q2 is the azimuth nonlinear signal; s2 is the azimuth nonlinear integral signal; ε1, ε2, k1, k2, k3, d1, d2, d3 are constant parameter signals;

[0018] In an example embodiment of the present application, according to the pitch signal of the UAV, first, the angular velocity estimation filter is designed to obtain the pitch angular velocity estimation filter signal; then the angular acceleration estimation filter is designed to obtain the pitch angular acceleration estimation filter signal; and the two are superimposed to obtain the pitch damping combined signal, including:

[0019]

[0020] q d1 =q d11 +q d12 ;

[0021] Wherein q d11 is the pitch angular acceleration estimation filter signal; qd12 q is the pitch angle velocity estimation filter signal; q d1 a1, a2, a3, a4 are constant filter parameter signals; s is a differential operator of a transfer function.

[0022] In an example embodiment of the application, according to the azimuth signal of the unmanned aerial vehicle, an angular velocity estimation filter is first designed to obtain an azimuth angular velocity estimation filter signal; then an angular acceleration estimation filter is designed to obtain an azimuth angular acceleration estimation filter signal; and the two are superimposed to obtain an azimuth damping combined signal including:

[0023]

[0024] q d2 = q d21 + q d22 ;

[0025] q d21 is the azimuth angular acceleration estimation filter signal; q d22 is the azimuth angular velocity estimation filter signal; q d2 is the azimuth damping combined signal.

[0026] In an example embodiment of the application, according to the pitch signal of the unmanned aerial vehicle, a pitch nonlinear signal, a pitch nonlinear integral signal, a pitch angular acceleration estimation filter signal, a pitch angular velocity estimation filter signal, a linear combination is performed to obtain a pitch comprehensive signal; then according to the pitch comprehensive signal, a pitch disturbance compensation adaptive law, a pitch disturbance nonlinear compensation adaptive law, a pitch damping disturbance compensation adaptive law, a pitch position disturbance compensation adaptive law are designed; and through integration, a pitch disturbance compensation coefficient, a pitch disturbance nonlinear compensation coefficient, a pitch damping disturbance compensation coefficient, a pitch position disturbance compensation coefficient are obtained; and a combination is performed to obtain a pitch disturbance compensation comprehensive signal; then the pitch comprehensive signal and a pitch comprehensive nonlinear transformation signal are superimposed to form an unmanned aerial vehicle pitch photoelectric guidance signal including:

[0027] s a1 = p 11 θ1+ p 12 q1+ p 13 s1+ p 14 q d11 + p 15 q d12 ;

[0028]

[0029]

[0030] u a1 = f 11 sa1 +f 12 u a10 +T a1 ;

[0031] wherein s a1 is a pitch comprehensive signal; p 11 , p 12 , p 13 , p 14 , p 15 is a constant parameter signal, is a pitch interference compensation adaptive law; is a pitch damping interference compensation adaptive law; is a pitch position interference compensation adaptive law; is a pitch interference compensation coefficient; is a pitch damping interference compensation coefficient; is a pitch position interference compensation coefficient; k a1 , k a2 , k a3 is a constant parameter for adjusting the convergence speed of the adaptive law; T a1 is a pitch interference compensation comprehensive signal; u a10 is a pitch comprehensive nonlinear transformation signal, ε3, f 11 , f 12 is a constant parameter; u a1 is a UAV pitch photoelectric guidance signal.

[0032] In an example embodiment of the application, a linear combination is performed according to the azimuth signal, the azimuth nonlinear signal, the azimuth nonlinear integral signal, the azimuth angle acceleration estimation filter signal, and the azimuth angle velocity estimation filter signal of the UAV to obtain an azimuth comprehensive signal; then, an azimuth interference compensation adaptive law, an azimuth interference nonlinear compensation adaptive law, an azimuth damping interference compensation adaptive law, and an azimuth position interference compensation adaptive law are designed according to the azimuth comprehensive signal; and an azimuth interference compensation coefficient, an azimuth interference nonlinear compensation coefficient, an azimuth damping interference compensation coefficient, and an azimuth position interference compensation coefficient are obtained through integration; and a combination is performed to obtain an azimuth interference compensation comprehensive signal; then, the azimuth comprehensive signal and the pitch comprehensive nonlinear transformation signal are superimposed to form a UAV azimuth photoelectric guidance signal, which comprises:

[0033] s a2 = p 21 θ2+p 22 q2+p 23 s2+p 24 q d21 +p 25 q d22 ;

[0034]

[0035]

[0036] u a2 = f 21 s a2 + f 22 u a20 + T a2 ;

[0037] wherein s a2 is an azimuth comprehensive signal; p 21 , p 22 , p 23 , p 24 , p 25 are constant parameter signals, is an azimuth interference compensation adaptive law; is an azimuth damping interference compensation adaptive law; is an azimuth position interference compensation adaptive law; is an azimuth interference compensation coefficient; is an azimuth damping interference compensation coefficient; is an azimuth position interference compensation coefficient; k b1 , k b2 , k b3 are constant parameters for adjusting the convergence speed of the adaptive law; T a2 is an azimuth interference compensation comprehensive signal; u a20 is an azimuth comprehensive nonlinear transformation signal, epsilon4, f 21 , f 22 are constant parameters, u a2 is an unmanned aerial vehicle azimuth photoelectric guidance signal.

[0038] Advantages

[0039] The unmanned aerial vehicle landing guidance method using photoelectric guidance interference compensation has the following two main innovations: first, an estimated filter of the pitch azimuth angle speed and the angle acceleration is adopted, which can solve the estimated value of the angle differential and the second-order differential, and has the functions of filtering and damping, which provides sufficient damping in the landing control and achieves good results, greatly improving the stability of the unmanned aerial vehicle landing. Second, the angle, damping and position deviation are estimated for the interference existing in the landing control, and the position deviation no longer directly participates in the control, but only adjusts in the interference compensation, which is essentially different from the general landing control. The above interference compensation method further improves the precision of the landing control, so that the present application has high engineering practical value.

[0040] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. Attached Figure Description

[0041] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0042] Figure 1 This is a flowchart of a UAV landing guidance method using photoelectric guidance interference compensation provided by the present invention.

[0043] Figure 2 This is the pitch signal curve (unit: degrees) of the UAV using the method provided in the embodiments of the present invention;

[0044] Figure 3 This is the azimuth signal curve (unit: degrees) of the UAV provided by the method in the embodiments of the present invention;

[0045] Figure 4 This refers to the distance information (unit: meters) between the UAV and the landing point provided by the method in this embodiment of the invention.

[0046] Figure 5 This is the pitch nonlinear integral signal curve (unitless) of the UAV provided by the method in the embodiments of the present invention;

[0047] Figure 6 This is the nonlinear integral signal curve of the UAV orientation (unitless) provided by the method in the embodiments of the present invention;

[0048] Figure 7 This is the UAV pitch rate estimation filter signal curve (unitless) provided by the method in the embodiments of the present invention;

[0049] Figure 8 This is the filter signal curve (unitless) for estimating the azimuth angular velocity of a UAV using the method provided in this embodiment of the invention;

[0050] Figure 9 This is the drone altitude change curve (unit: meters) provided by the method in the embodiments of the present invention;

[0051] Figure 10 This is a curve showing the lateral position change of the UAV (unit: meters) according to the method provided in this embodiment of the invention. Detailed Implementation

[0052] Example implementations will now be described, by way of example only, with reference to the attached drawings. These implementations are examples only and should not be construed in a limiting sense. Rather, they are provided to more fully describe exemplary implementations of the application. Numerous specific details are described, to provide a thorough understanding of the implementation(s). However, one skilled in the relevant art will recognize that the implementation(s) can be practiced without one or more of the specific details. In other instances, well-known details are not described, to avoid obscuring aspects of the implementation(s). Reference will now be made to the drawings to describe the exemplary implementations in greater detail.

[0053] The present application provides a kind of by landing field on photoelectric guidance system's infrared thermal imager and laser range finder to measure the pitch direction and distance information of unmanned aerial vehicle and resolve vertical and lateral approximate deviation signal;Again, pitch direction signal is carried out nonlinear transformation and integration and speed and acceleration filtering processing, respectively, pitch direction nonlinear transformation, integral, angular velocity filtering and angular acceleration filtering estimation signal are obtained, and integrated signal is formed, then adaptive algorithm is used to estimate and compensate the interference of the process of landing from position, damping and angle three aspects, finally, pitch and azimuth attitude angle expected signal is formed, is sent to unmanned aerial vehicle attitude angle stabilization system, so as to realize the stable control of photoelectric guidance landing.

[0054] Below, the photoelectric guidance interference compensation of a kind of unmanned aerial vehicle landing guide method of the present application will be further explained and described in combination with the drawings. Figure 1 As shown in the figure, the photoelectric guidance interference compensation of a kind of unmanned aerial vehicle landing guide method can include the following steps:

[0055] Step S10, the pitch signal and azimuth signal of unmanned aerial vehicle are measured by the infrared thermal imager of landing field on photoelectric guidance system, the distance information of unmanned aerial vehicle from landing point is measured by the laser range finder of landing field on photoelectric guidance system;And according to the distance information of unmanned aerial vehicle from landing point and the pitch signal of unmanned aerial vehicle, the vertical approximate deviation signal of unmanned aerial vehicle is calculated;According to the distance information of unmanned aerial vehicle from landing point and the azimuth signal of unmanned aerial vehicle, the lateral approximate deviation signal of unmanned aerial vehicle is calculated.

[0056] Specifically, first, the pitch signal of unmanned aerial vehicle is measured by the infrared thermal imager of photoelectric guidance system, and is recorded as θ1;Then, the azimuth signal of unmanned aerial vehicle is measured by the infrared thermal imager of photoelectric guidance system, and is recorded as θ2. The distance information of unmanned aerial vehicle from landing point is measured by the laser range finder of landing field on photoelectric guidance system, and is recorded as r.

[0057] Secondly, the vertical approximate deviation signal of the UAV is calculated according to the distance information of the UAV from the landing point and the pitch signal of the UAV as follows:

[0058] y a =r sin(θ1);

[0059] wherein y a is the vertical approximate deviation signal of the UAV.

[0060] Finally, the lateral approximate deviation signal of the UAV is calculated according to the distance information of the UAV from the landing point and the azimuth signal of the UAV as follows:

[0061] z a =r sin(θ2);

[0062] wherein z a is the lateral approximate deviation signal of the UAV.

[0063] In step S20, the pitch nonlinear signal is obtained by performing nonlinear transformation on the pitch signal of the UAV; then the pitch nonlinear integral signal is obtained by performing combined integration on the pitch signal of the UAV and the pitch nonlinear signal; the azimuth nonlinear signal is obtained by performing nonlinear transformation on the azimuth signal of the UAV; then the azimuth nonlinear integral signal is obtained by performing combined integration on the azimuth signal of the UAV and the azimuth nonlinear signal.

[0064] Specifically, first, the pitch nonlinear signal is obtained by performing nonlinear transformation on the pitch signal of the UAV as follows:

[0065]

[0066] wherein q1 is the pitch nonlinear signal; k1, k2, k3 are constant parameter signals.

[0067] Secondly, the azimuth nonlinear signal is obtained by performing nonlinear transformation on the azimuth signal of the UAV as follows:

[0068]

[0069] wherein q2 is the azimuth nonlinear signal; d1, d2, d3 are constant parameter signals.

[0070] Thirdly, the pitch nonlinear integral signal is obtained by performing combined integration on the pitch signal of the UAV and the pitch nonlinear signal as follows:

[0071]

[0072] wherein s1 is the pitch nonlinear integral signal.

[0073] Finally, the azimuth signal of the unmanned aerial vehicle and the azimuth nonlinear signal are combined and integrated to obtain an azimuth nonlinear integrated signal as follows:

[0074]

[0075] where s2 is the azimuth nonlinear integrated signal.

[0076] In step S30, according to the pitch signal of the unmanned aerial vehicle, an angular velocity estimation filter is first designed to obtain a pitch angular velocity estimation filtered signal; then an angular acceleration estimation filter is designed to obtain a pitch angular acceleration estimation filtered signal; and the two are superimposed to obtain a pitch damping combined signal; and according to the azimuth signal of the unmanned aerial vehicle, an angular velocity estimation filter is first designed to obtain an azimuth angular velocity estimation filtered signal; then an angular acceleration estimation filter is designed to obtain an azimuth angular acceleration estimation filtered signal; and the two are superimposed to obtain an azimuth damping combined signal.

[0077] Specifically, according to the pitch signal of the unmanned aerial vehicle, an angular velocity estimation filter is first designed to obtain a pitch angular velocity estimation filtered signal as follows:

[0078]

[0079] where q d12 is the pitch angular velocity estimation filtered signal; s is a differential operator of a transfer function. a2 and a4 are constant filter parameter signals.

[0080] Secondly, according to the pitch signal of the unmanned aerial vehicle, an angular acceleration estimation filter is designed to obtain a pitch angular acceleration estimation filtered signal as follows:

[0081]

[0082] where q d11 is the pitch angular acceleration estimation filtered signal, and a1 and a3 are constant filter parameter signals.

[0083] Thirdly, the two are superimposed to obtain a pitch damping combined signal as follows:

[0084] q d1 = q d11 + q d12 ;

[0085] where q d1 is the pitch damping combined signal.

[0086] Then, according to the azimuth signal of the unmanned aerial vehicle, an angular acceleration estimation filter is designed to obtain an azimuth angular acceleration estimation filtered signal as follows:

[0087]

[0088] wherein q d22 is the azimuth angle velocity estimation filter signal.

[0089] Further, according to the azimuth signal of the unmanned aerial vehicle, an angular acceleration estimation filter is designed to obtain an azimuth angular acceleration estimation filter signal as follows:

[0090]

[0091] wherein q d21 is the azimuth angular acceleration estimation filter signal.

[0092] Finally, the above two are superimposed to obtain an azimuth damping combined signal as follows:

[0093] q d2 = q d21 + q d22 ;

[0094] wherein q d2 is the azimuth damping combined signal.

[0095] Step S40, linearly combining the pitch signal, the pitch nonlinear signal, the pitch nonlinear integral signal, the pitch angular acceleration estimation filter signal, and the pitch angular velocity estimation filter signal to obtain a pitch comprehensive signal; then designing a pitch interference compensation adaptive law, a pitch interference nonlinear compensation adaptive law, a pitch damping interference compensation adaptive law, and a pitch position interference compensation adaptive law according to the pitch comprehensive signal; and obtaining a pitch interference compensation coefficient, a pitch interference nonlinear compensation coefficient, a pitch damping interference compensation coefficient, and a pitch position interference compensation coefficient through integration; and combining to obtain a pitch interference compensation comprehensive signal; then superimposing the pitch comprehensive signal and the pitch comprehensive nonlinear transformation signal to form an unmanned aerial vehicle pitch photoelectric guidance signal, which is sent to the unmanned aerial vehicle pitch angle tracking system, so as to realize the vertical automatic landing of the unmanned aerial vehicle.

[0096] Specifically, first, linearly combining the pitch signal, the pitch nonlinear signal, the pitch nonlinear integral signal, the pitch angular acceleration estimation filter signal, and the pitch angular velocity estimation filter signal to obtain a pitch comprehensive signal as follows:

[0097] s a1 = p 11 θ1+p 12 q1+p 13 s1+p 14 q d11 +p 15 q d12 ;

[0098] wherein s a1is the pitch comprehensive signal; p 11 is the pitch comprehensive signal; p 12 is the pitch comprehensive signal; p 13 is the pitch comprehensive signal; p 14 is the pitch comprehensive signal; p 15 is the constant parameter signal.

[0099] Secondly, according to the pitch comprehensive signal, the pitch interference compensation adaptive law, the pitch interference nonlinear compensation adaptive law, the pitch damping interference compensation adaptive law, and the pitch position interference compensation adaptive law are designed as follows:

[0100]

[0101] wherein is the pitch interference compensation adaptive law; is the pitch damping interference compensation adaptive law; is the pitch position interference compensation adaptive law.

[0102] Thirdly, the pitch interference compensation coefficient, the pitch interference nonlinear compensation coefficient, the pitch damping interference compensation coefficient, and the pitch position interference compensation coefficient are obtained by integration as follows:

[0103]

[0104] wherein is the pitch interference compensation coefficient; is the pitch damping interference compensation coefficient; is the pitch position interference compensation coefficient; k a1 is the constant parameter, which is used to adjust the convergence speed of the adaptive law. a2 is the constant parameter, which is used to adjust the convergence speed of the adaptive law. a3 is the constant parameter, which is used to adjust the convergence speed of the adaptive law.

[0105] Then, the pitch interference compensation coefficients are combined to obtain the pitch interference compensation comprehensive signal as follows:

[0106]

[0107] wherein T a1 is the pitch interference compensation comprehensive signal.

[0108] Finally, the pitch interference compensation comprehensive signal is superimposed with the pitch comprehensive signal and the pitch comprehensive nonlinear transformation signal to form the unmanned aerial vehicle pitch photoelectric guidance signal as follows:

[0109]

[0110] u a1 = f 11 s a1 + f 12 u a10 + T a1 ;

[0111] wherein u a10 is the pitch comprehensive nonlinear transformation signal, u a1 is the unmanned aerial vehicle pitch photoelectric guidance signal; ε3, f 11 , f 12 are constant parameters.

[0112] Step S50, linearly combining the azimuth signals of the unmanned aerial vehicle, the azimuth nonlinear signals, the azimuth nonlinear integral signals, the azimuth angle acceleration estimation filter signals and the azimuth angle velocity estimation filter signals to obtain an azimuth comprehensive signal; then designing an azimuth interference compensation adaptive law, an azimuth interference nonlinear compensation adaptive law, an azimuth damping interference compensation adaptive law and an azimuth position interference compensation adaptive law according to the azimuth comprehensive signal; and obtaining an azimuth interference compensation coefficient, an azimuth interference nonlinear compensation coefficient, an azimuth damping interference compensation coefficient and an azimuth position interference compensation coefficient through integration; and combining to obtain an azimuth interference compensation comprehensive signal; then superimposing the azimuth comprehensive signal and the pitch comprehensive nonlinear transformation signal to form an unmanned aerial vehicle azimuth photoelectric guidance signal and delivering the signal to an unmanned aerial vehicle azimuth angle tracking system, so as to realize the lateral automatic landing of the unmanned aerial vehicle.

[0113] Specifically, first, linearly combining the azimuth signals of the unmanned aerial vehicle, the azimuth nonlinear signals, the azimuth nonlinear integral signals, the azimuth angle acceleration estimation filter signals and the azimuth angle velocity estimation filter signals to obtain an azimuth comprehensive signal as follows:

[0114] s a2 = p 21 θ2+ p 22 q2+ p 23 s2+ p 24 q d21 + p 25 q d22 ;

[0115] wherein s a2 is the azimuth comprehensive signal; p 21 , p 22 , p 23 , p 24 , p 25 are constant parameter signals.

[0116] Second, designing an azimuth interference compensation adaptive law, an azimuth interference nonlinear compensation adaptive law, an azimuth damping interference compensation adaptive law and an azimuth position interference compensation adaptive law according to the azimuth comprehensive signal as follows:

[0117]

[0118]

[0119] wherein is an azimuth interference compensation adaptive law; is an azimuth damping interference compensation adaptive law; is an azimuth position interference compensation adaptive law.

[0120] Again, the azimuth interference compensation coefficient, the azimuth interference nonlinear compensation coefficient, the azimuth damping interference compensation coefficient, and the azimuth position interference compensation coefficient are obtained by integration as follows:

[0121]

[0122] wherein is an azimuth interference compensation coefficient; is an azimuth damping interference compensation coefficient; is an azimuth position interference compensation coefficient; k b1 , k b2 , k b3 is a constant parameter for adjusting the convergence speed of the adaptive law.

[0123] Then, the azimuth interference compensation coefficients are combined to obtain an azimuth interference compensation comprehensive signal as follows:

[0124]

[0125] wherein T a2 is an azimuth interference compensation comprehensive signal.

[0126] Finally, the azimuth interference compensation comprehensive signal is superimposed with the azimuth comprehensive signal and the azimuth comprehensive nonlinear transformation signal to form a UAV azimuth photoelectric guidance signal as follows:

[0127]

[0128] u a2 = f 21 s a2 + f 22 u a20 + T a2 ;

[0129] wherein u a20 is an azimuth comprehensive nonlinear transformation signal, u a2 is a UAV azimuth photoelectric guidance signal; ε4, f 21 , f 22 are constant parameters.

[0130] Case implementation and computer simulation result analysis

[0131] In step S10, an infrared thermal imager of a photoelectric guidance system is used to measure the pitch signal of the UAV, such as Figure 2As shown; then, the infrared thermal imager of the photoelectric guidance system is used to measure the azimuth signal of the UAV, such as... Figure 3 As shown. The laser rangefinder of the electro-optical guidance system at the landing site is used to measure the distance between the UAV and the landing point, such as... Figure 4 As shown.

[0132] In step S20, k1 = 8, k2 = 0.5, k3 = 0.8, d1 = 12, d2 = 0.7, and d3 = 0.9 are selected. The resulting pitch nonlinear integral signal is shown below. Figure 5 As shown; the azimuth nonlinear integral signal is as follows Figure 6 As shown.

[0133] In step S30, a2 = 12.5; a4 = 0.05; a1 = 0.25; a3 = 0.125 are selected; the pitch angular velocity estimation filter signal is obtained as follows: Figure 7 As shown, the azimuth angular velocity estimation filtered signal is obtained as follows: Figure 8 As shown.

[0134] In step S40, p is selected. 11 =0.3, p 12 =0.7, p 13 =0.6, p 14 =0.1, p 15 =0.3, ε3=0.5, f 11 =-4, f 12 = -0.15, and the final drone altitude change curve is shown in Figure 9.

[0135] In step S50, p is selected. 21 =0.35, p 22 =0.9, p 23 =0.8, p 24 =0.15, p 25 =0.35, ε4=0.5, f 21 =-6、f 22 = -0.18, and the final curve of the UAV's lateral position change is shown in Figure 10.

[0136] Figure 2 This indicates that the initial pitch angle is approximately 15 degrees; Figure 3 This indicates that the initial segment azimuth is approximately 1.8 degrees; Figure 4 This indicates that the initial distance of the drone was approximately 525 meters. Figure 9 As can be seen, with the assistance of electro-optical guidance, the drone smoothly descended from an altitude of 160 meters, eventually landing at a height of 0 meters on the landing site. Figure 10It can be seen that the unmanned aerial vehicle starts to correct quickly from the initial position of 15 meters laterally, and finally the lateral error is stabilized at about 0 meters, realizing accurate landing. The overall landing process is fast, accurate and has small shock. From the overall experimental results, the method provided by the application embodies good stability and precision, thereby indicating the effectiveness of the photoelectric guidance and interference compensation of the method, and having high engineering application and popularization value.

Claims

1. A landing guidance method for unmanned aerial vehicles (UAVs) employing photoelectric guidance interference compensation, characterized in that, Includes the following steps: Step S10: The infrared thermal imager of the electro-optical guidance system on the landing site is used to measure the pitch and azimuth signals of the UAV; the laser rangefinder of the electro-optical guidance system on the landing site is used to measure the distance information of the UAV from the landing point; and the vertical approximate deviation signal of the UAV is calculated based on the distance information of the UAV from the landing point and the UAV's pitch signal; the lateral approximate deviation signal of the UAV is calculated based on the distance information of the UAV from the landing point and the UAV's azimuth signal as follows: y a =rsin(θ1); z a =rsin(θ2); θ1 represents the pitch signal of the UAV measured by an infrared thermal imager using an electro-optical guidance system; θ2 represents the azimuth signal of the UAV measured by an infrared thermal imager using an electro-optical guidance system; r represents the distance information of the UAV from the landing point measured by a laser rangefinder using an electro-optical guidance system at the landing site; and y represents the distance information of the UAV from the landing point measured by a laser rangefinder using an electro-optical guidance system at the landing site. a This is the approximate vertical deviation signal for the UAV; z a This is an approximate lateral deviation signal for the UAV; Step S20: Based on the pitch signal of the UAV, a nonlinear transformation is performed to obtain a pitch nonlinear signal; then, the pitch signal and the pitch nonlinear signal are combined and integrated to obtain a pitch nonlinear integral signal; based on the azimuth signal of the UAV, a nonlinear transformation is performed to obtain an azimuth nonlinear signal; then, the azimuth signal and the azimuth nonlinear signal are combined and integrated to obtain the following azimuth nonlinear integral signal: Where q1 is the pitch nonlinear signal; s1 is the pitch nonlinear integral signal; q2 is the azimuth nonlinear signal; s2 is the azimuth nonlinear integral signal; ε1, ε2, k1, k2, k3, d1, d2, and d3 are constant parameter signals; Step S30: Based on the pitch signal of the UAV, firstly design an angular velocity estimation filter to obtain a pitch angular velocity estimation filter signal; then design an angular acceleration estimation filter to obtain a pitch angular acceleration estimation filter signal. The two signals are then superimposed to obtain the pitch damping combined signal. Based on the UAV's azimuth signal, an angular velocity estimation filter is first designed to obtain the azimuth angular velocity estimation filter signal; then an angular acceleration estimation filter is designed to obtain the azimuth angular acceleration estimation filter signal. Finally, the two signals are superimposed to obtain the azimuth damping combined signal as follows: q d1 =q d11 +q d12 ; q d2 =q d21 +q d22 ; Where q d11 Filtered signal for pitch angle acceleration estimation; q d12 Filtered signal for pitch angular velocity estimation; q d1 For pitch damping combined signal; q d21 Filtered signal for azimuth acceleration estimation; q d22 Filtered signal for azimuth angular velocity estimation; q d2 is the azimuth damping combination signal; a1, a2, a3, a4 are constant filter parameter signals; s is the differential operator of the transfer function; Step S40: Linearly combine the pitch signal, pitch nonlinear signal, pitch nonlinear integral signal, pitch angular acceleration estimation filter signal, and pitch angular velocity estimation filter signal of the UAV to obtain the comprehensive pitch signal; Then, based on the pitch synthesis signal, we designed the pitch interference compensation adaptive law, the pitch interference nonlinear compensation adaptive law, the pitch damping interference compensation adaptive law, and the pitch position interference compensation adaptive law. The pitch interference compensation coefficient, pitch interference nonlinearity compensation coefficient, pitch damping interference compensation coefficient, and pitch position interference compensation coefficient are obtained through integration. These are then combined to obtain the pitch interference compensation composite signal. Finally, the composite pitch signal and the composite pitch nonlinear transformation signal are superimposed to form the UAV pitch electro-optical guidance signal, which is sent to the UAV pitch angle tracking system to achieve the UAV's vertical automatic landing as follows: s a1 =p 11 θ1+p 12 q1+p 13 s1+p 14 q d11 +p 15 q d12 ; u a1 =f 11 s a1 +f 12 u a10 +T a1 ; Where s a1 For pitch synthesis signal; p 11 p 12 p 13 p 14 p 15 For constant parameter signals, An adaptive law for pitch interference compensation; An adaptive law for pitch damping interference compensation; An adaptive law for pitch position disturbance compensation; This is the pitch interference compensation coefficient; This is the pitch damping interference compensation coefficient; k is the pitch position interference compensation coefficient. a1 k a2 k a3 T is a constant parameter used to adjust the convergence speed of the adaptive law; a1 For pitch interference compensation integrated signal; u a10 For pitch synthesis nonlinear transformation signals, ε3, f 11 f 12 A constant parameter; u a1 For UAV pitch photoelectric guidance signals; Step S50: Linearly combine the azimuth signal, azimuth nonlinear signal, azimuth nonlinear integral signal, azimuth angular acceleration estimation filter signal, and azimuth angular velocity estimation filter signal of the UAV to obtain the comprehensive azimuth signal. Then, based on the azimuth integrated signal, we design the azimuth interference compensation adaptive law, the azimuth interference nonlinear compensation adaptive law, the azimuth damping interference compensation adaptive law, and the azimuth position interference compensation adaptive law. The azimuth interference compensation coefficient, azimuth interference nonlinearity compensation coefficient, azimuth damping interference compensation coefficient, and azimuth position interference compensation coefficient are obtained by integration. The signals are then combined to obtain a comprehensive signal with azimuth interference compensation. Then, the azimuth composite signal and the pitch composite nonlinear transformation signal are superimposed to form the UAV's azimuth electro-optical guidance signal, which is then transmitted to the UAV's azimuth angle tracking system to achieve the UAV's automatic lateral landing as follows: s a2 =p 21 θ2+p 22 q2+p 23 s2+p 24 q d21 +p 25 q d22 ; u a2 =f 21 s a2 +f 22 u a20 +T a2 ; Where s a2 For azimuth composite signal; p 21 p 22 p 23 p 24 p 25 For constant parameter signals, An adaptive law for azimuth interference compensation; An adaptive law for azimuth damping interference compensation; An adaptive law for azimuth and position interference compensation; This is the azimuth interference compensation coefficient; This is the azimuth damping interference compensation coefficient; k is the azimuth and position interference compensation coefficient. b1 k b2 k b3 This is a constant parameter used to adjust the convergence speed of the adaptive law; T a2 For azimuth interference compensation integrated signal; u a20 For the azimuth synthesis nonlinear transformation signal, ε4, f 21 f 22 For constant parameters, u a2 This is for the orientation and photoelectric guidance signal of the UAV.

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