A multi-constraint collaborative guidance method based on event triggering mechanism

Abstract

The present invention discloses a multi-constraint collaborative guidance method of an event-triggered mechanism, in which a coupled relative motion model is established in a three-dimensional space in each aircraft, and by introducing the concept of three-dimensional offset proportional guidance, the offset term is used to make the remaining flight time of all aircraft tend to be consistent under the condition of satisfying the maximum field of view angle constraint; the method uses a distributed collaborative guidance law, which can effectively reduce the frequency of data transmission between individuals compared with a continuous control method, overcome the limitation of communication and improve the communication transmission efficiency; the distributed communication network can effectively avoid the single point failure problem of the centralized communication topology, and the expected attack time does not need to be set in advance before launching, and the aircraft group performs discontinuous communication and finally completes the collaborative guidance task.

Description

Technical Field

[0001] The present invention relates to the technical field of cooperative control of multiple aircrafts, and in particular to a multi-constraint cooperative guidance method based on an event triggering mechanism. Background Art

[0002] With the gradual development of technology, it is becoming increasingly difficult for traditional aircraft to break through blockades and hit targets. The coordinated attack of multiple aircraft uses a group of aircraft to form an attack network, realizes information interaction between aircraft, and significantly improves the aircraft's penetration capability, accurate target identification capability, and electronic countermeasure capability. In addition, the simultaneous attack of multiple aircraft can form a saturation attack on the defense system, and it is difficult for enemy ship targets to respond to attacks from different directions in a short period of time. Therefore, time coordination plays a vital role in modern warfare. At present, this multi-aircraft coordination strategy is considered to be an effective countermeasure to penetrate powerful defense systems.

[0003] From the existing literature, the guidance strategies for achieving simultaneous attacks can be mainly divided into two methods. The first is the time-controlled guidance of a single aircraft, that is, each aircraft in the multi-aircraft attacks the target at the expected time without communicating with other aircraft. Although this guidance strategy does not require a communication network, it is necessary to estimate the attack time range of each aircraft based on the positional relationship between the aircraft and the target and the maneuverability of each missile before launching, and select a common expected attack time from the intersection of the flight time ranges of each aircraft, and finally achieve simultaneous attack. When the expected attack time is set unreasonably, it may lead to the failure of the simultaneous attack mission, and it is not a coordinated attack in essence.

[0004] The second guidance strategy is to achieve time-coordinated guidance by introducing a communication network into the aircraft group. There are many existing literatures, but most of them are studied in a two-dimensional plane. In order to be closer to the actual situation, it is necessary to fully consider the coupling effect of the lateral channel and the longitudinal channel, design the time-coordinated guidance law in a three-dimensional scene, and consider the field of view constraint of the seeker.

[0005] Since neighborhood communication is used to transfer information between aircraft, it is difficult to ensure that each aircraft continuously exchanges information to achieve system consistency in actual situations. In addition, the energy of each aircraft is limited, making it difficult to complete tasks such as continuous state sampling, information transfer, and collaborative control system updates.

[0006] Therefore, how to effectively reduce the communication volume and control the system update frequency to achieve sparse, effective and flexible response while ensuring the stability of the system is the focus of current research.

[0007] Based on the above problems, the inventors have conducted in-depth research on multi-cooperative guidance methods and aircraft, hoping to design a multi-constraint cooperative guidance method based on an event-triggered mechanism that can solve the above problems. Summary of the invention

[0008] In order to overcome the above problems, the inventors have conducted intensive research and designed a multi-constraint collaborative guidance method based on an event-triggered mechanism, in which a coupled relative motion model is established in three-dimensional space in each aircraft, and the concept of three-dimensional offset proportional guidance is introduced, and the offset term is used to make the remaining flight time of all aircraft tend to be consistent under the condition of satisfying the maximum field of view angle constraint; the method uses a distributed collaborative guidance law, which can effectively reduce the frequency of data transmission between individuals compared to the continuous control method, overcome the communication limitations and improve the communication transmission efficiency; the distributed communication network can effectively avoid the single point failure problem of the centralized communication topology, and the expected attack time does not need to be set in advance before launch, and the aircraft group conducts discontinuous communication and finally completes the collaborative guidance task, thereby completing the present invention.

[0009] Specifically, the purpose of the present invention is to provide a multi-constraint collaborative guidance method based on an event trigger mechanism.

[0010] The aircraft obtains the position and speed information of the aircraft in real time through the satellite navigation system carried on it, and transmits it to the guidance module;

[0011] After the aircraft meets the triggering conditions, the aircraft interacts with the neighboring aircraft for the remaining flight time through the inter-missile communication module carried on it, and transmits the obtained remaining flight time of the neighboring aircraft to the guidance module;

[0012] Obtaining an acceleration instruction based on the received information by the guidance module;

[0013] The control module generates rudder instructions based on the acceleration instructions, and then controls the servo steering gear to adjust the attitude of the aircraft.

[0014] After the aircraft meets the trigger condition, the acceleration instruction obtained by the guidance module includes a pitch acceleration instruction and a yaw acceleration instruction;

[0015] The pitch acceleration command and the yaw acceleration command are obtained by the following formula (1):

[0016]

[0017] Among them, a y,i represents the pitch acceleration command on the i-th aircraft,

[0018] a z,irepresents the yaw acceleration command on the i-th aircraft,

[0019] N represents the proportional guidance coefficient,

[0020] V i represents the speed of the ith aircraft,

[0021] r i represents the distance between the i-th aircraft and the target,

[0022] φ i It represents the leading deviation angle of the velocity vector of the ith aircraft relative to the missile-target line of sight,

[0023] θ i represents the forward inclination angle of the velocity vector of the ith aircraft relative to the missile-target line of sight,

[0024] σ i represents the velocity lead angle of the i-th aircraft,

[0025] represents the ratio of the velocity lead angle of the ith aircraft to its maximum allowable value,

[0026] ρ() represents a nonlinear function,

[0027] u i It represents the consistent control quantity of the remaining flight time of the i-th aircraft.

[0028] The beneficial effects of the present invention include:

[0029] (1) The multi-constraint collaborative guidance method based on the event trigger mechanism provided by the present invention has less communication volume and higher communication transmission efficiency than other methods, thereby ensuring that each aircraft can complete tasks such as state sampling, information transmission and collaborative control system update;

[0030] (2) According to the multi-constraint cooperative guidance method based on the event trigger mechanism provided by the present invention, the method utilizes the time cooperative guidance law in the three-dimensional scene and considers the field of view angle constraint of the seeker, which is closer to the actual situation and fully considers the coupling effect of the lateral channel and the longitudinal channel;

[0031] (3) According to the multi-constraint collaborative guidance method based on the event trigger mechanism provided by the present invention, the frequency of data transmission between individuals is effectively reduced by adopting a distributed collaborative guidance law, thereby overcoming communication limitations and improving communication transmission efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The communication topology diagram between four aircrafts in the embodiment is shown;

[0033] Figure 2The flight trajectories of the four aircraft in the embodiment are shown.

[0034] Figure 3 The remaining flight time of the four aircraft in the embodiment changes with time.

[0035] Figure 4 The curves showing the change of pitch acceleration instructions of the four aircrafts in the embodiment over time are shown.

[0036] Figure 5 The curves showing the changes of the yaw acceleration instructions of the four aircrafts in the embodiment over time are shown.

[0037] Figure 6 The curves showing the change of the speed lead angles of the four aircrafts in the embodiment with time are shown.

[0038] Figure 7 The event triggering interval diagram and the cooperative controller updating interval diagram of four aircraft with a sampling step of 0.02s in the embodiment are shown. DETAILED DESCRIPTION

[0039] 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.

[0040] 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.

[0041] According to a multi-constraint collaborative guidance method based on an event trigger mechanism provided by the present invention, Figure 1 As shown in , the aircraft obtains the position information and speed information of the aircraft in real time through the satellite navigation system carried thereon.

[0042] After the aircraft meets the trigger condition, the aircraft exchanges the remaining flight time with the neighboring aircraft through the inter-missile communication module carried on it, and transmits the remaining flight time of the neighboring aircraft to the guidance module; in the present application, the inter-missile communication module transmits the remaining flight time of the aircraft itself to the outside, and its transmission frequency is 4Hz, and its information update frequency is 50Hz. The inter-missile communication module is continuously turned on during the guidance stage to receive information, and only transmits information to the outside after the trigger condition is met, and transmits its own remaining flight time to the outside once each time the trigger condition is met.

[0043] The guidance module obtains an acceleration instruction according to the received information;

[0044] The control module generates rudder instructions based on the acceleration instructions, and then controls the servo steering gear to adjust the attitude of the aircraft.

[0045] In a preferred embodiment, in the guidance module, an acceleration instruction is obtained by a distributed collaborative guidance law, and the acceleration instruction includes a pitch acceleration instruction and a yaw acceleration instruction;

[0046] The pitch acceleration command and the yaw acceleration command are obtained by the following formula (1):

[0047]

[0048] Among them, a y,i represents the pitch acceleration command on the i-th aircraft,

[0049] a z,i represents the yaw acceleration command on the i-th aircraft,

[0050] N represents the proportional guidance coefficient, and its value is 4;

[0051] V i represents the speed of the ith aircraft, which is obtained in real time by the satellite navigation system on the ith aircraft;

[0052] r i It represents the distance between the ith aircraft and the target. The position of the ith aircraft is obtained in real time by the satellite navigation system on the ith aircraft, and is obtained by real-time calculation based on the target position information loaded into the aircraft before the aircraft is launched.

[0053] φ i It represents the leading deviation angle of the velocity vector of the i-th aircraft relative to the missile-target line of sight, which can be calculated using the frame angle information measured by the airborne seeker. Specifically,

[0054]

[0055] θ g and ψ g Represents the frame angle of the seeker head on the aircraft.

[0056]

[0057] θ i represents the forward tilt angle of the velocity vector of the ith aircraft relative to the missile-target line of sight, which can be calculated using the frame angle information measured by the airborne seeker. Specifically,

[0058]

[0059] σ irepresents the velocity lead angle of the i-th aircraft, which is also the heading error for attacking a stationary target;

[0060] represents the ratio of the velocity lead angle of the ith aircraft to its maximum allowable value,

[0061] ρ() represents a nonlinear function,

[0062] u i It represents the consistent control quantity of the remaining flight time of the i-th aircraft.

[0063] Preferably, the Obtained by the following formula (II):

[0064]

[0065] Among them, σ imax represents the maximum allowable value of the ith aircraft speed lead angle, which is preferably 45° in the present application.

[0066] Preferably, the nonlinear function ρ() is as shown in the following formula (III):

[0067] ρ(x)=1-|x| m (three)

[0068] Wherein, x represents any variable, for example, in this application, x is taken as

[0069] m represents a design parameter, and preferably takes a value of 1.

[0070] Preferably, the velocity lead angle σ of the i-th aircraft is i Obtained by the following formula (IV):

[0071] σ i =arccos(cosθ i cosφ i ) (Four).

[0072] Preferably, the u i Obtained by the following formula (V):

[0073]

[0074] Wherein, c represents the control gain, which is a positive constant, preferably 0.6;

[0075] n represents the number of aircraft, which can be set according to the specific situation. For example, it can be set to 4, that is, 4 aircraft are set to attack the target in coordination;

[0076] u i(t) represents the consistent control value of the remaining flight time of the ith aircraft at time t,

[0077] Indicates the i-th aircraft at its triggering time An estimate of the remaining flight time for the transmission,

[0078] Indicates that the i-th aircraft is The estimated remaining flight time of the j-th aircraft received at time ,

[0079] N i represents the neighbor set of the ith aircraft. In the present application, the neighbors refer to aircraft that can be connected with its signal and thus transmit the remaining flight time estimation value.

[0080] In this application, after the trigger condition is met, each aircraft will obtain the remaining flight time estimate transmitted by the neighboring aircraft at a certain interval. Each time the acceleration instruction is obtained by solving, the remaining flight time estimate transmitted by each neighboring aircraft is retrieved for solving. Since the update time of each aircraft is different from the update time of other aircraft, and Not necessarily equal.

[0081] Preferably, the remaining flight time estimate is obtained by the following formula (VI):

[0082]

[0083] Among them, t goi represents the estimated remaining flight time of the i-th aircraft.

[0084] In a preferred embodiment, the information transmitted by the sensors and the inter-missile communication module on the aircraft is monitored by an event detector, and whether the event triggering conditions are met is determined according to the defined event triggering function. Once the triggering conditions are found to be met, the current remaining flight time is calculated and passed to the neighboring UAVs. During the guidance and control process of the aircraft, continuous calculations are required to determine whether the triggering conditions are met.

[0085] The trigger condition is that the trigger function is greater than 0, and the trigger function is shown in the following formula (VII):

[0086]

[0087] Among them, g i (t) represents the trigger function of the ith aircraft,

[0088] e i (t) represents the local error of the ith aircraft,

[0089] a represents the design parameter, and 0<a<(1 / |N i |), preferably with a value of 0.4,

[0090] s i represents the design parameter, and 0<s i <1, preferably 0.9,

[0091] |N i | represents the set N i The momentum,

[0092] Represents the remaining flight time consistency error determined by the triggering amount.

[0093] In Formula 7 of the present application, the next triggering time is obtained through the current triggering information.

[0094] Preferably, the local error amount e i (t) is obtained by the following formula (VIII):

[0095]

[0096] in, express The remaining flight time of the i-th aircraft at the time triggers the communication volume. The moment refers to the trigger moment closest to the current moment; That is, the corresponding remaining flight time value when it was last triggered;

[0097] t goi (t) represents the real-time remaining flight time of the i-th aircraft, which is obtained by formula 6.

[0098] Preferably, the Obtained by the following formula (IX):

[0099]

[0100] in, represents a piecewise constant variable;

[0101] express The remaining flight time of the i-th aircraft triggers the communication volume, that is, The remaining flight time of the i-th aircraft transmitted outward at any time;

[0102] express The remaining flight time of the jth aircraft at the moment triggers the communication traffic. In this application, the start-up time of the aircraft can be considered as the triggering time without the need to be judged by formula (VII). After the start-up time, it is judged in real time based on formula (VII) whether the triggering condition is met. If the triggering condition is met, the remaining flight time of the aircraft is transmitted to the outside once, that is, it is updated once. That is to say, in the adjacent trigger interval, the cooperative controller in the aircraft will use the zero-order hold method to keep its output at a fixed value.

[0103] The collaborative controller and the event detector used to detect trigger conditions in the present application only use their own information and neighbor aircraft trigger information. The distributed architecture reduces the amount of information obtained from remote neighbor aircraft.

[0104] Example

[0105] Set up four aircraft M1, M2, M3 and M4. The initial conditions of the four aircraft are shown in Table 1:

[0106] Table 1

[0107] Aircraft Position / m Speed / (m / s) Front tilt angle / (°) Front deflection angle / (°) <![CDATA[M1]]> (6000,0,7000) 260 10 10 <![CDATA[M2]]> (7000,0,6000) 270 20 15 <![CDATA[M3]]> (8000,0,5000) 260 25 -15 <![CDATA[M4]]> (9000,0,4000) 280 15 -20

[0108] The target is a stationary object located at the origin;

[0109] The communication topology between the four aircraft is as follows: Figure 1 shown.

[0110] The following methods are used for guidance and control in each aircraft:

[0111] By simulating the satellite navigation system with computers, each aircraft is given its own position and speed information in real time;

[0112] After the aircraft meets the triggering conditions, the aircraft interacts with the neighboring aircraft through the inter-missile communication module carried on it to determine the remaining flight time, and transmits the remaining flight time of the neighboring aircraft to the guidance module;

[0113] Obtaining an acceleration instruction based on the received information by the guidance module;

[0114] The control module generates rudder instructions based on the acceleration instructions, and then controls the servo steering gear to adjust the attitude of the aircraft.

[0115] The acceleration command includes a pitch acceleration command and a yaw acceleration command, which are specifically obtained by the following formula (1):

[0116]

[0117] Obtained by the following formula (II):

[0118]

[0119] The nonlinear function ρ() is shown in the following formula (III):

[0120] ρ(x)=1-|x| m (three)

[0121] The design parameter m takes the value of 1;

[0122] The velocity lead angle σ of the i-th aircraft i Obtained by the following formula (IV):

[0123] σ i =arccos(cosθ i cosφ i ) (Four).

[0124] u i Obtained by the following formula (V):

[0125]

[0126] The remaining flight time estimate is obtained by the following formula (VI):

[0127]

[0128] The trigger condition is that the trigger function is greater than 0, and the trigger function is shown in the following formula (VII):

[0129]

[0130] Local error e i (t) is obtained by the following formula (VIII):

[0131]

[0132] Said Obtained by the following formula (IX):

[0133]

[0134] The above parameters are set as N = 4, c = 0.6, a = 0.4, s i =0.9,σ imax =45°.

[0135] Further consider the first-order lag link of the autopilot (a m / a m,c )=1 / (Ts+1), where a mIt is the acceleration index actually used to generate the rudder command. m,c It is the acceleration instruction obtained by the guidance module using the above method, and Ts=0.2s.

[0136] The simulation results obtained based on the above method are as follows Figures 2 to 5 As shown, Figure 2 The flight paths of four aircraft are shown. Figure 3 The remaining flight time of the four aircrafts varies with time. Figure 4 The curves showing the pitch acceleration commands of the four aircrafts changing with time are shown. Figure 5 The curves showing the changes of yaw acceleration commands of the four aircraft over time are shown. Figure 6 The curves showing the change of the velocity lead angle of the four aircraft over time are shown. Figure 7 The event trigger interval diagram and cooperative controller update interval diagram of 4 aircraft with a sampling step of 0.02s are shown;

[0137] Depend on Figure 2 It can be seen that under the control of the method provided by the present invention, the four aircraft can accurately hit the target.

[0138] Depend on Figure 3 It can be seen that the remaining flight time of all aircraft can reach a consensus before hitting the target, thus ensuring simultaneous attack.

[0139] Depend on Figure 4 and Figure 5 It can be seen that a larger acceleration command is required in the initial stage to make the remaining flight time of all aircraft tend to be consistent, and finally the guidance command converges to zero, so that a stable hit can be achieved.

[0140] Depend on Figure 6 It can be seen that all aircraft can meet the maximum field of view angle constraint of the seeker.

[0141] Depend on Figure 7 It can be seen that event-triggered control can significantly reduce the number of updates of the collaborative controller; it can be further seen that under the control of the control method provided in the present application, the trigger interval and trigger time of each aircraft are different, thereby achieving more effective energy-saving control for each aircraft, and ultimately the aircraft group can hit the target at the same time with a miss margin of less than 0.1m, meeting actual engineering needs.

[0142] In the above embodiment, the flight time of each aircraft is 36.34s. During the flight, the number of data transmissions between aircraft using event-triggered control is about 4% of the number of data transmissions using continuous control. It can be seen that this method has a lower requirement for the transmission frequency between aircraft, less communication volume and higher communication transmission efficiency.

[0143] 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 multi-constraint cooperative guidance method based on an event-triggered mechanism, characterized in that the aircraft obtains the position information and velocity information of the aircraft in real time through the satellite navigation system carried thereon, and transmits them to the guidance module; after the aircraft meets the trigger condition, the aircraft interacts with neighboring aircraft for the remaining flight time through the inter-missile communication module carried thereon, and transmits the obtained remaining flight time of the neighboring aircraft to the guidance module; the guidance module obtains an acceleration command based on the received information; the control module generates a rudder command based on the acceleration command, and then controls the servo rudder to deflect to adjust the attitude of the aircraft, after the aircraft meets the trigger condition, the acceleration commands obtained by the guidance module include a pitch acceleration command and a yaw acceleration command; the pitch acceleration command and the yaw acceleration command are obtained by the following formula (I): Among them, a y,i represents the pitch acceleration command on the i-th aircraft, a z,i represents the yaw acceleration command on the i-th aircraft, N represents the proportional navigation coefficient, V i represents the speed of the ith aircraft, r i represents the distance between the i-th aircraft and the target, φ i It represents the leading deviation angle of the velocity vector of the ith aircraft relative to the missile-target line of sight, θ i represents the forward inclination angle of the velocity vector of the ith aircraft relative to the missile-target line of sight, σ i represents the velocity lead angle of the i-th aircraft, represents the ratio of the velocity lead angle of the ith aircraft to its maximum allowable value, ρ() represents a non-linear function, u i It represents the consistent control quantity of the remaining flight time of the i-th aircraft.

2. The multi-constraint cooperative guidance method based on an event-triggered mechanism according to claim 1, characterized in that Said Obtained by the following formula (II): Among them, σ imax Represents the maximum allowable value of the velocity lead angle of the ith aircraft.

3. The multi-constraint cooperative guidance method based on an event-triggered mechanism according to claim 1, characterized in that the non-linear function ρ() is as shown in the following formula (III): ρ(x) = 1 - |x|m (III) where x represents any variable; m represents a design parameter.

4. The multi-constraint cooperative guidance method based on an event-triggered mechanism according to claim 1, characterized in that The velocity lead angle σ of the i-th aircraft i Obtained by the following formula (IV): σ i = arccos(cosθ i cosφ i )(IV).

5. The multi-constraint cooperative guidance method based on an event-triggered mechanism according to claim 1, characterized in that The u i Obtained by the following formula (V): where c represents a control gain, and its value is a positive constant, n represents the number of aircraft, u i (t) represents the consistent control value of the remaining flight time of the ith aircraft at time t, Indicates the i-th aircraft at its triggering time An estimate of the remaining flight time for the transmission, Indicates that the i-th aircraft is The estimated remaining flight time of the j-th aircraft received at time , N i represents the neighbor set of the ith aircraft, where the neighbors refer to the aircraft that can be connected to its signal and thus transmit the remaining flight time estimation value.

6. The multi-constraint cooperative guidance method based on an event-triggered mechanism according to claim 5, characterized in that the estimated value of the remaining flight time is obtained by the following formula (VI): Among them, t goi represents the estimated remaining flight time of the i-th aircraft.

7. The multi-constraint cooperative guidance method based on an event-triggered mechanism according to claim 1, characterized in that the trigger condition is that the trigger function is greater than 0, and the trigger function is as shown in the following formula (VII): Among them, g i (t) represents the trigger function of the ith aircraft, e i (t) represents the local error of the ith aircraft, a represents a design parameter, and 0 < a < (1 / |Ni|), s i represents the design parameters, and 0<s i <1, N i | represents the set N i The momentum, Represents the remaining flight time consistency error determined by the triggering amount.

8. The multi-constraint cooperative guidance method based on an event-triggered mechanism according to claim 7, characterized in that The local error e i (t) is obtained by the following formula (VIII): in, express The remaining flight time of the i-th aircraft triggers the communication volume, t goi (t) represents the real-time remaining flight time of the i-th aircraft.

9. The multi-constraint cooperative guidance method based on an event-triggered mechanism according to claim 7, characterized in that Said Obtained by the following formula (IX): in, represents a piecewise constant variable; express The remaining flight time of the i-th aircraft triggers the communication volume, express The remaining flight time of the jth aircraft at time instant triggers the communication traffic.

Images