Non-singular robust quantized control method for networked communication aircraft

Abstract

The present invention discloses a non-singular robust quantization control method suitable for networked communication aircraft, in which robust, fast and accurate tracking control is achieved through non-singular terminal sliding mode control. It is worth mentioning that the control signal obtained by the control method is smooth and jitter-free, and then a uniform quantizer is introduced to convert the continuous signal into a discrete signal, which saves communication resources and reduces energy loss.

Description

Technical Field

[0001] The present invention relates to the technical field of attitude control of aircraft, and in particular to a non-singular robust quantized control method suitable for networked communication aircraft. Background Art

[0002] Sliding mode control is widely used in linear and nonlinear system control with parameter uncertainty and external disturbances due to its advantages such as strong robustness, fast response speed and simple implementation. However, traditional linear sliding mode control can only guarantee asymptotic convergence. Although finite-time sliding mode control has faster convergence characteristics, it also faces the problem of high-frequency jitter, which will increase the wear of mechanical components and stimulate high-frequency unmodeled dynamics, resulting in system performance degradation or even loss of stability. In addition, traditional aircraft use wired communication between the controller and the actuator, which will generate more energy loss during signal transmission.

[0003] Based on this, the inventors have conducted in-depth research on sliding mode control in the hope of designing a control method that can solve the chattering problem. Summary of the invention

[0004] In order to overcome the above problems, the inventors have conducted intensive research and designed a non-singular robust quantization control method suitable for networked communication aircraft, in which robust, fast and accurate tracking control is achieved through non-singular terminal sliding mode control. It is worth mentioning that the control signal obtained by the control method is smooth and jitter-free, and then a uniform quantizer is introduced to convert the continuous signal into a discrete signal, saving communication resources and reducing energy loss, thereby completing the present invention.

[0005] Specifically, the purpose of the present invention is to provide a non-singular robust quantization control method suitable for networked communication aircraft. In this method, continuous control instructions are obtained in real time by a controller, and then the continuous control instructions are input into a quantizer to obtain discrete control signals, which are transmitted to an actuator through a network, thereby controlling the aircraft to track a desired tracking signal.

[0006] Wherein, the controller obtains continuous control instructions in real time through the following formula (1);

[0007]

[0008] in, Indicates continuous control instructions;

[0009] I represents the inertia matrix;

[0010] J represents the rotation matrix;

[0011] represents the derivative of J;

[0012] Λ represents an antisymmetric matrix;

[0013] ω represents the attitude angular velocity vector;

[0014] α, β, k, γ each independently represent a control parameter; preferably, β>0 and 1<α<2;

[0015] s represents a sliding variable;

[0016] Represents η d The second derivative of d Indicates the desired tracking signal;

[0017] Represents the derivative of e, which is obtained by differentiating the tracking error e.

[0018] Wherein, the sliding variable s is obtained by the following formula (II):

[0019]

[0020] Among them, the tracking error e is obtained by the following formula (III):

[0021] e=η-η d (three)

[0022] η represents the angle vector.

[0023] Among them, the expression of the inertia matrix I is as follows (IV):

[0024]

[0025] Among them, I xx ,I xy ,I xy ,I yy ,I yz ,I zz They all independently represent the inertial parameters.

[0026] Among them, the expression of the rotation matrix J is as follows (5):

[0027]

[0028] Wherein, φ represents the roll angle and θ represents the pitch angle.

[0029] Among them, the expression of the antisymmetric matrix Λ is as follows (6):

[0030]

[0031] Where p represents the rolling angular velocity,

[0032] q is the pitch angular velocity,

[0033] r represents the yaw angular velocity.

[0034] Wherein, the quantizer obtains a discrete control signal through the following formula (VII):

[0035]

[0036] Where M represents a discrete control signal;

[0037] μ represents a quantizer parameter, preferably, μ>0.

[0038] The beneficial effects of the present invention include:

[0039] (1) According to the non-singular robust quantized control method for networked communication aircraft provided by the present invention, in this method, even in the presence of large external interference, the roll angle, pitch angle and yaw angle can track the desired tracking signal very quickly and accurately, and the fast response speed is conducive to system stability;

[0040] (2) According to the non-singular robust quantization control method applicable to networked communication aircraft provided by the present invention, the control signal obtained by the method has no jitter, thereby avoiding a large oscillation frequency and damage to the actuator, effectively protecting the actuator and prolonging the service life of the actuator;

[0041] (3) According to the non-singular robust quantization control method for networked communication aircraft provided by the present invention, the controller and the actuator communicate via a network to avoid the influence of limited communication resources on the control accuracy. By providing a uniform quantizer, the continuous control signal is converted into a discrete control signal, thereby saving communication resources while ensuring the influence of control accuracy.

[0042] (4) According to the non-singular robust quantized control method suitable for networked communication aircraft provided by the present invention, the method adds protection for the actuator, reduces the wear of the actuator, saves energy and reduces energy consumption compared with traditional communication means. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The tracking curve of the roll angle of the aircraft in the embodiment is shown;

[0044] Figure 2 The tracking curve of the pitch angle of the aircraft in the embodiment is shown;

[0045] Figure 3 The tracking curve of the yaw angle of the aircraft in the embodiment is shown;

[0046] Figure 4The tracking error curve of the aircraft attitude angle in the embodiment is shown;

[0047] Figure 5 The embodiment shows that the aircraft has a quantizer roll channel moment;

[0048] Figure 6 The rolling channel moment of the aircraft without quantizer in the embodiment is shown;

[0049] Figure 7 The pitch channel moment of the aircraft having a quantizer in the embodiment is shown;

[0050] Figure 8 The pitch channel moment of the aircraft without quantizer in the embodiment is shown;

[0051] Fig. 9 The aircraft in the embodiment is shown to have a yaw channel moment of a quantizer;

[0052] Fig.10 The yaw channel moment of the aircraft without a quantizer in the embodiment is shown. DETAILED DESCRIPTION

[0053] The present invention will be further described in detail below through the accompanying drawings and embodiments. Through these descriptions, the characteristics and advantages of the present invention will become more clear and distinct.

[0054] The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

[0055] The present invention provides a non-singular robust quantization control method suitable for networked communication aircraft, in which a continuous control instruction is obtained in real time by a controller, and then the continuous control instruction is input into a quantizer to obtain a discrete control signal, and the discrete control signal is transmitted to an actuator through a network, thereby controlling the aircraft to track a desired tracking signal. The actuator is preferably a steering gear on the aircraft, and the aircraft attitude is controlled by controlling the steering condition of the steering gear, so that the aircraft tracks the desired tracking signal.

[0056] In a preferred embodiment, the controller obtains continuous control instructions in real time through the following formula (1);

[0057]

[0058] in, Indicates continuous control instructions;

[0059] I represents the inertia matrix; the expression of the inertia matrix I is as follows (IV)

[0060]

[0061] I xx ,I xy ,I xz ,I yy ,I yz ,I zz They all independently represent the inertial parameters.

[0062] J represents a rotation matrix; the expression of the rotation matrix J is as follows (5);

[0063]

[0064] φ represents the roll angle, and θ represents the pitch angle.

[0065] represents the derivative of J;

[0066] Λ represents an antisymmetric matrix; the expression of the antisymmetric matrix Λ is the following formula (VI);

[0067]

[0068] Where p represents the roll angular velocity,

[0069] q represents the pitch angular velocity,

[0070] r represents the magnitude of the yaw angular velocity.

[0071] ω represents the attitude angular velocity vector, which is a vector composed of the roll angular velocity, the pitch angular velocity and the yaw angular velocity. The specific value is obtained by real-time detection by the sensors on the aircraft.

[0072] α, β, k, and γ each independently represent a control parameter; preferably, β>0 and 1<α<2; more preferably, the specific values ​​are: α=1.5, β=1, k=40, γ=0.8.

[0073] s represents a sliding variable;

[0074] Represents η d The second derivative of

[0075] η d Indicates the expected tracking signal; that is, the actual attitude angle of the aircraft is controlled to track the expected tracking signal to make it as consistent as possible; the expected tracking signal includes time-varying attitude angles in three directions, and the attitude angles in three directions are roll angle, pitch angle and yaw angle.

[0076] represents the derivative of e, which is obtained by differentiating the tracking error e;

[0077] Preferably, the tracking error e is obtained by the following formula (III):

[0078] e=η-η d (three)

[0079] η represents an angle vector, which is a vector composed of roll angle, pitch angle and yaw angle. The specific value is obtained by real-time detection by sensors on the aircraft.

[0080] Preferably, the sliding variable s is obtained by the following formula (ii):

[0081]

[0082] In a preferred embodiment, in the networked control of an aircraft, a digital communication network is used to exchange information between control system components, so that the controller is digitally implemented based on the sampled measurement values ​​transmitted by the sensor; in many engineering applications, sharing limited network bandwidth may reduce the performance of the network control system or cause it to be unstable. Quantization can be regarded as the process of converting a continuous signal into its discrete mapping, thereby reducing the computational workload of the network control system.

[0083] In the present application, a quantizer is introduced between the controller and the actuator to discretize the continuous control signal; the quantizer obtains a discrete control signal through the following formula (VII);

[0084]

[0085] Where M represents a discrete control signal;

[0086] μ represents a quantizer parameter, preferably, μ>0; more preferably, the value of the quantizer parameter μ is 10000. In the present application, the discrete degree of the discrete control signal, that is, the frequency of the signal is selected and controlled by adjusting the value of the quantizer parameter.

[0087] Example

[0088] Simulate in MATLAB / Simulink environment;

[0089] The expected tracking signal η d =[0.5sin(t),0.4cos(t),0.3sin(t)] T , that is, the expected tracking signal of the roll angle is 0.5sin(t), the expected tracking signal of the pitch angle is 0.4cos(t), and the expected tracking signal of the yaw angle is 0.3sin(t);

[0090] The interference of the external environment on the aircraft is:

[0091]

[0092] The initial state of the aircraft is: η(0) = [0.5, 0.5, 0.5] T rad,ω(0)=[0,0,0] T rad / s.

[0093] In the specific simulation process, the aircraft attitude is controlled by the following methods:

[0094] The continuous control command is obtained in real time through (I), and then a discrete control signal is obtained through (VII). The discrete control signal is transmitted to the steering gear through the network, and then the steering gear steers according to the control command, thereby adjusting the attitude of the aircraft.

[0095]

[0096] The specific form of the inertia matrix I is:

[0097]

[0098] The expression of the rotation matrix J is:

[0099]

[0100] φ represents the roll angle, θ represents the pitch angle;

[0101] represents the derivative of J;

[0102] The expression of the antisymmetric matrix Λ is:

[0103]

[0104] Where p represents the roll angular velocity,

[0105] q represents the pitch angular velocity,

[0106] r represents the magnitude of the yaw angular velocity.

[0107] ω represents the attitude angular velocity vector, which is obtained by real-time measurement;

[0108] The values ​​of control parameters are: α = 1.5, β = 1, k = 40, γ = 0.8;

[0109] s represents a sliding variable;

[0110] Represents η d The second derivative of

[0111] η d Indicates the desired tracking signal;

[0112] represents the derivative of e, which is obtained by differentiating the tracking error e; the tracking error e is obtained by the following formula (III);

[0113] e=η-η d (three)

[0114] η represents the angle vector, which is obtained by real-time measurement;

[0115] The sliding variable s is obtained by the following formula (II);

[0116]

[0117] Where M represents a discrete control signal;

[0118] The value of the quantizer parameter μ is 10000.

[0119] The final simulation results are as follows: Figures 1 to 10 shown.

[0120] Figure 1 A tracking curve showing the roll angle of the aircraft; Figure 2 A tracking curve showing the pitch angle of the aircraft; Figure 3 A tracking curve showing the aircraft's yaw angle; Figure 4 A tracking error curve showing the attitude angle of the aircraft; Figure 4 e in φ represents the roll angle tracking error, e θ represents the pitch angle tracking error, e ψ Represents the yaw angle tracking error;

[0121] Figure 5 Shows the rolling channel moment of the aircraft with quantizer; Figure 6 The roll channel torque of the aircraft without a quantizer is shown, that is, the roll channel torque obtained by directly transmitting the continuous control command in formula (1) to the actuator;

[0122] Figure 7 It shows that the aircraft has a quantizer pitch channel moment; Figure 8 The pitch channel torque of the aircraft without a quantizer is shown, that is, the pitch channel torque obtained by directly transmitting the continuous control command in formula (1) to the actuator;

[0123] Fig. 9 It is shown that the aircraft has a quantizer for the yaw channel moment; Fig.10 The yaw channel torque of the aircraft without a quantizer is shown, that is, the yaw channel torque obtained by directly transmitting the continuous control command in formula (1) to the actuator;

[0124] according to Figures 1 to 4 From the results, we can see that even in the presence of large external interference, the roll angle, pitch angle and yaw angle can track the reference attitude signal very quickly and accurately. Basically, accurate tracking is achieved in about 2 seconds. The fast response speed helps stabilize the system.

[0125] Depend on Figures 5 to 10 It can be seen that both control signals with and without the quantizer are jitter-free.

[0126] After using the quantizer, the continuous signal becomes a segmented discrete signal, which reduces the occupancy of the communication channel and saves communication resources. This is of great practical significance in actual engineering applications, especially in working scenarios where limited network bandwidth is shared. Figures 1 to 4 It can be seen that the non-singular robust quantized control method applicable to networked communication aircraft provided in the present application and the control scheme of the aircraft ensure tracking accuracy while saving communication resources.

[0127] The above simulation results show that the non-singular robust quantized control method suitable for networked communication aircraft provided by the present invention is more outstanding in that it has a very fast response speed, strong robustness, high tracking accuracy, saves network communication resources and smoothes the control signal, and has good practical engineering significance.

[0128] The present invention has been described above in conjunction with preferred embodiments, but these embodiments are only exemplary and serve only as an illustration. On this basis, the present invention may be subjected to a variety of substitutions and improvements, all of which fall within the scope of protection of the present invention.

Claims

1. A non-singular robust quantized control method suitable for networked communication aircraft, characterized in that: In the method, a continuous control instruction is obtained in real time by a controller, and then the continuous control instruction is input into a quantizer to obtain a discrete control signal, and the discrete control signal is transmitted to an actuator through a network, thereby controlling the aircraft to track a desired tracking signal; The controller obtains continuous control instructions in real time through the following formula (1); in, Indicates continuous control instructions; I represents the inertia matrix; J represents the rotation matrix; represents the derivative of J; Λ represents an antisymmetric matrix; ω represents the attitude angular velocity vector; α, β, k, γ each independently represent control parameters; β>0 and 1<α<2; s represents a sliding variable; Represents η d The second derivative of d Indicates the desired tracking signal; represents the derivative of e, which is obtained by differentiating the tracking error e; The sliding variable s is obtained by the following formula (II): The expression of the rotation matrix J is as follows (5): Among them, φ represents the roll angle, θ represents the pitch angle; The expression of the antisymmetric matrix Λ is as follows (6): Where p represents the roll angular velocity, q represents the pitch angular velocity, r represents the magnitude of the yaw angular velocity.

2. The non-singular robust quantized control method for networked communication aircraft according to claim 1, characterized in that: The tracking error e is obtained by the following formula (III): e = η - η d (III) η represents the real-time angle vector of the aircraft.

3. The non-singular robust quantized control method for networked communication aircraft according to claim 1, characterized in that: The expression of the inertia matrix I is as follows (IV): Among them, I xx ,I xy ,I xz ,I yy ,I yz ,I zz They all independently represent the inertial parameters.

4. The non-singular robust quantized control method for networked communication aircraft according to claim 1, characterized in that: The quantizer obtains a discrete control signal through the following formula (VII); Where M represents a discrete control signal; μ represents the quantizer parameter, μ>0.

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