Disclosure of Invention
Aiming at the prior art, the invention aims to provide a multi-unmanned aerial vehicle tight formation control method based on pigeon swarm optimization, which avoids the control by using formation errors and improves the control speed and the control precision.
In order to solve the technical problem, the invention discloses a multi-unmanned aerial vehicle tight formation control method based on pigeon swarm optimization, which comprises the following steps:
the method comprises the following steps: setting control instruction U of unmanned aerial vehicle long machine
L=[V
Lcψ
Lch
Lc]And formation expected spacing
Wherein
Representing the desired longitudinal spacing between a prolonged and a bureaucratic machine,
representing the desired lateral spacing between a long and a bureaucratic plane,
representing the expected distance between the longerons and the bureaucratic machines in the height direction, establishing a compact formation mathematical model, and utilizing the control commands U of the longerons
L=[V
Lcψ
Lch
Lc]And current state quantity X of the long machine
L=[V
Lψ
Lh
L]Calculating the state quantity X of the long machine at the next moment
LnextWherein V is
LcSpeed control command, psi, representing a longplane
LcRepresenting a course angle control command of the long plane; h is
LcHeight control command, V, representing a long machine
LRepresenting the speed of the long machine; psi
LRepresenting the heading angle of the long plane; h is
LRepresents the height of the long machine;
step two: the state X of the long machine at the next momentLnextQuantity of current state of bureaucratic planeFInputting the expected formation distance D into an artificial potential field controller, and calculating the ideal state of the unmanned aerial vehicle formation in the next step, wherein XF=[x VFy ψFz ζ]TX, y and z represent the distance between the wing plane and the farm plane; vFThe speed of a representative wing plane; psiFA course angle representing a wing plane; zeta represents the speed difference in the direction of the height of a wing plane and a long plane;
step three: calculating the control quantity of a bureau plane by utilizing an improved pigeon group optimization algorithm;
step four: inputting the control quantity of a bureaucratic machine into a compact formation model of the bureaucratic machine to calculate the next state quantity of the bureaucratic machine;
step five: and repeating the second step to the fourth step until the simulation duration.
The invention also includes:
1. the tight formation mathematical model comprises: the pilot plane automatic pilot model and the six-degree-of-freedom state space model of the wing plane meet the following conditions:
wherein, tau
VRepresenting the drone speed time constant; tau is
ψRepresenting a course time constant of the unmanned aerial vehicle;
and
representing the unmanned aerial vehicle altitude time constant;
the state space model of six degrees of freedom of the wing plane satisfies:
UFc=[VFcψFchFc]Tamount of bureaucratic; z ═ VLψLhLc]TThe coupling quantity of the long machine is set; the specific elements of each matrix are as follows:
in the formula
The initial speed of the long machine is set as,
is the average aerodynamic pressure, S is the wing area, m is the total mass, V is the air velocity equal to the unmanned aerial vehicle speed,
in order to have a one time constant for the height,
is the height time constant two;
a rate time constant of a wing aircraft, the value of which corresponds to τ
VThe same;
as a wing aircraft course time constant, its value and τ
ψThe same is true.
Is the component of the lateral force increment coefficient in the y direction;
is the component of the incremental coefficient of resistance in the y direction;
is the component of the lateral force increment coefficient in the z direction;
is the component of the lift delta coefficient in the y-direction.
Calculating the state quantity X of the long machine at the next momentLnextThe method specifically comprises the following steps: will be long machine control instruction ULAnd current state quantity X of long machineL=[VLψLhL]Inputting the model of the automatic pilot of the pilot machine to obtain the next time state X of the pilot machineLnext。
2. In the second step, the motion equation of the unmanned aerial vehicle in the artificial potential field controller is expressed as the following formula:
in the formula xiA position vector representing an ith drone; v. ofiRepresenting a velocity vector of an ith drone; m isiRepresenting the mass of the ith drone; u. ofiA control vector representing an ith drone; k is a radical ofiviRepresenting the velocity damping vector of the ith robot, where uiRepresented by the formula:
ui=αi+βi+γi+kivi
formula (III) αiRepresenting the speed consistency control quantity of the ith unmanned plane and the adjacent unmanned planes βiRepresenting the distance potential field control quantity of the ith unmanned aerial vehicle and the adjacent unmanned aerial vehicle; gamma rayiRepresenting the formation speed consistency control quantity of the ith unmanned aerial vehicle and the multi-unmanned aerial vehicle system; v. ofendA set system formation speed is set; vijRepresenting the set distance potential field function, the control quantity can be expressed as:
in the formula KvRepresenting a velocity feedback gain factor; kpRepresenting a potential field feedback gain factor, wherein a distance potential field function VijThe settings were as follows:
in the formula xijNamely the distance between two adjacent unmanned aerial vehicles at present;
the state quantity of the leader at the next moment can be used for obtaining the formation at the next moment, namely the ideal state quantity X of the leader at the next momentFnextThat is, the control quantity u currently suffered by the wing plane is calculated by the speed difference and the position difference between the next moment of the lead plane and the current moment of the wing plane and the stable speed difference between the wing plane and the set formationiAnd then the position, the speed and the course of the wing plane at the next moment are calculated by the unmanned plane motion equation.
3. In the third step, the calculation of the amount of controlling of the bureaucratic machines by utilizing the improved pigeon group optimization algorithm is as follows: selecting particle X as bureaucratic control quantity in improved pigeon group algorithm
Updating the set X, and updating the rule as follows:
updating rules of quantum particle swarms:
and (3) improving a landmark operator updating rule:
β=round(1+rand)
wherein α is contraction-expansion coefficient, β is learning factor, XpbestRepresenting individual historyThe quality is excellent; xgbestRepresents global history optimality; xmbestRepresenting the optimal average of individual history, and outputting X after iteration is completedgbestBureau of bureau plane control UFcAnd Nc is the current iteration number.
4. The input of the controlling quantity of the wing plane into the compact formation of the wing plane model in the fourth step is concretely as follows:
will find the UFcA state space model with six degrees of freedom and with bureaucratic machines:
thus obtaining the actual state quantity X 'at the next moment of the wing plane'Fnext。
The invention has the beneficial effects that: the invention provides a new compact formation control scheme based on an unmanned aerial vehicle state space equation under compact formation and by considering the difference between an expected formation state and an actual formation state, and realizes formation control by taking the consistency difference of the two states as control input. Compared with the traditional PID controller scheme, the method avoids the control by utilizing the formation error, improves the control speed and the control precision, and can complete the high-precision compact formation task in a larger unmanned aerial vehicle range. The invention provides a new scheme for the formation control of multiple unmanned aerial vehicles under the condition of tight formation, and has higher engineering application value.
Detailed Description
The present invention will be described in further detail with reference to specific examples.
The invention provides a multi-unmanned aerial vehicle compact formation system control method based on an improved pigeon swarm optimization algorithm and an improved artificial potential field method. And estimating the bureaucratic control quantity which can lead the bureaucratic state quantity at the next moment to be the closest to the bureaucratic control quantity at the ideal state by utilizing an improved pigeon swarm optimization algorithm, thereby completing the formation task. The invention has the significance of providing a multi-unmanned aerial vehicle formation control scheme under the condition of compact formation, and the multi-unmanned aerial vehicle formation control scheme has the advantages of high convergence speed, high steady-state precision and higher engineering application value.
Fig. 1 shows a schematic diagram of a multi-unmanned aerial vehicle system formation control scheme based on an improved pigeon swarm algorithm and an artificial potential field method, which is provided by the invention, and mainly aims at solving the problems that multi-unmanned aerial vehicle formation has strong coupling, strong nonlinearity and the like under a tight formation condition. The method comprises the following steps:
the method comprises the following steps: and setting a long-machine control instruction of the unmanned aerial vehicle and an expected formation interval, and establishing a compact formation mathematical model. And calculating the state quantity of the long machine at the next moment by using the control instruction of the long machine and the current state quantity of the long machine. As shown in FIG. 1, before the formation begins, a control command U of the captain of the unmanned aerial vehicle needs to be set
L=[V
Lcψ
Lch
Lc]Wherein the formation takes place at the desired spacing
And a mathematical model during tight formation, including a longplane autopilot model:
in the formula tau
VRepresenting the drone speed time constant; tau is
ψRepresenting a course time constant of the unmanned aerial vehicle;
and
representing the unmanned aerial vehicle altitude time constant; v
LRepresenting the speed of the long machine; psi
LRepresenting the heading angle of the long plane; h is
LRepresents the height of the long machine; v
LcRepresenting a speed control command of the long machine; psi
LcRepresenting a course angle control command of the long plane; h is
LcRepresenting height control instructions for a long machine. Will be long machine control instruction U
LAnd current state quantity X of long machine
L=[V
Lψ
Lh
L]Inputting the model of the automatic pilot of the pilot machine to obtain the next time state X of the pilot machine
Lnext,
Represents the desired longitudinal spacing between a longplane and a bureaucratic plane;
represents the lateral desired spacing between a long and a bureaucratic plane;
representing the desired spacing in the direction of height between a longeron and a bureaucratic machine.
Spatial model of six degrees of freedom of wing plane:
in the formula XF=[x VFy ψFz ζ]TThe quantity of a wing plane state, x, y and z represent the distance between the wing plane and the long plane; vFThe speed of a representative wing plane; psiFA course angle representing a wing plane; zeta represents the speed difference in the direction of the height of a wing plane and a long plane. U shapeFc=[VFcψFchFc]TAmount of bureaucratic; z ═ VLψLhLc]TIs the coupling quantity of the long machine. The specific elements of each matrix are as follows:
in the formula
For the initial speed of the long aircraft, the specific parameters in the formula adopt F-16 aircraft model parameters given in Table 1.
Is the average aerodynamic pressure, S is the wing area, m is the total mass, V is the air velocity equal to the unmanned aerial vehicle speed,
in order to have a one time constant for the height,
is the height time constant two;
a rate time constant of a wing aircraft, the value of which corresponds to τ
VThe same; tau is
ψFAs a wing aircraft course time constant, its value and τ
ψThe same is true.
The component of the incremental coefficient of lateral force in the y direction is 0.0033;
the component of the incremental drag coefficient in the y-direction is-0.000782;
is the component of the lateral force increment coefficient in the z direction, and has the value of-0.0011;
the component of the lift increment coefficient in the y-direction is given a value of-0.0077.
TABLE 1F-16 parameter Table for unmanned aerial vehicle
Step two: the state X of the long machine at the next momentLnextCurrent state of bureaucratic plane XFAnd inputting the expected formation distance D into an artificial potential field controller, and calculating the ideal state of the unmanned aerial vehicle formation in the next step.
The equation of motion of the drone in the artificial potential field controller is expressed as:
in the formula xiA position vector representing an ith drone; v. ofiRepresenting a velocity vector of an ith drone; m isiRepresenting the mass of the ith drone; u. ofiA control vector representing an ith drone; k is a radical ofiviRepresenting the velocity damping vector for the ith robot. Wherein u isiRepresented by the formula:
ui=αi+βi+γi+kivi
formula (III) αiRepresenting the speed consistency control quantity of the ith unmanned plane and the adjacent unmanned planes βiRepresenting the distance potential field control quantity of the ith unmanned aerial vehicle and the adjacent unmanned aerial vehicle; gamma rayiRepresenting the formation speed consistency control quantity of the ith unmanned aerial vehicle and the multi-unmanned aerial vehicle system; v. ofendA set system formation speed is set; vijRepresenting the set distance potential field function, the control quantity can be expressed as:
in the formula KvRepresenting a velocity feedback gain factor; kpRepresenting the potential field feedback gain factor. Wherein the distance potential field function VijThe settings were as follows:
in the formula xijNamely the distance between two adjacent unmanned aerial vehicles at present. The state quantity of the leader at the next moment can be used for obtaining the formation at the next moment, namely the ideal state quantity X of the leader at the next momentFnextThat is, the control quantity u currently suffered by the wing plane is calculated by the speed difference and the position difference between the next moment of the lead plane and the current moment of the wing plane and the stable speed difference between the wing plane and the set formationiAnd then the position, the speed and the course of the wing plane at the next moment are calculated by the unmanned plane motion equation.
Step three: and calculating the control quantity of the bureaucratic machines by utilizing an improved pigeon swarm optimization algorithm.
Selecting particle X as bureaucratic control quantity in improved pigeon group algorithm
Updating the set X according to the flow of FIG. 2, the updating rule is as follows:
1 quantum particle swarm updating rule:
2, improving the landmark operator updating rule:
β=round(1+rand)
wherein α is contraction-expansion coefficient, β is learning factor, XpbestRepresenting individual history optimal; xgbestRepresents global history optimality; xmbestRepresenting the optimal average of the individual history. X output when iteration is completedgbestBureau of bureau plane control UFc。
f(XF)=(X′Fnext-XFnext)·(X′Fnext-XFnext)T,f(XF) The method is used for improving the fitness function of the pigeon group algorithm. X'Fnext、XFnextThe state quantities of a wing plane at the current moment and the ideal state quantity of a wing plane at the next moment, respectively, can be calculated from the flow chart in fig. 2 as a fitness function f (X)F) Amount of wing-plane control of the hourly space UFc=[VFcψFchFc]In the formula VFcControlling quantity, psi, of wing aircraft speedFcAmount of control of course angle of bureaucratic machine, hFcThe amount of the bureaucratic plane is controlled.
The method comprises the following specific steps:
the flow chart is shown in fig. 2, where the first loop is a compass operator loop and the second loop is a landmark operator loop. Each cycle updates the particles according to its specific update rule and then finds the one that minimizes the fitness function, i.e., is optimal. The fitness function value is optimized through continuous circulation, namely the difference between the actual state quantity of the representative wing plane and the ideal state quantity is minimum.
Step four: the control quantity of the bureaucratic plane is input into a tight formation model of the bureaucratic plane to calculate the next state quantity of the bureaucratic plane.
Will find the UFcA state space model with six degrees of freedom and with bureaucratic machines:
thus obtaining the actual state quantity X 'at the next moment of the wing plane'Fnext
Step five: and repeating the second step to the fourth step until the simulation duration.
Simulation verification:
simulation conditions are as follows: the desired formation pitch is set to [60ft,23.5ft,0ft ]; the initial formation state bureaucratic wing plane states are all [0ft/s,0 degrees, 0ft ]; the status of constant speed stable bureaucratic plane is [825ft/s,0 deg., 45000ft ]. The sampling period is 0.02s, and the simulation time is set to be 60 s; the long machine control can be divided into two stages: the first stage is that the heading control instruction of the first 15s long aircraft is uniformly reduced from zero to minus thirty degrees, and then the aircraft flies stably for 5 s; the second phase increases uniformly from minus thirty degrees to zero degrees during 20s to 35s and holds the control command for the simulation duration.
As can be seen from tables 2(a) to 2(c), the stable formation error x direction of the scheme of the invention can reach 0.15 inch at most under the condition of compact formation; a maximum of 0.08 inches in the y-direction; the z direction can be up to 0.3 inches.
Table 2(a) unmanned plane state at 15s
Table 2(b) unmanned plane state at 35s
TABLE 2(c) unmanned plane State at 60s
The specific implementation mode of the invention also comprises:
the method comprises the following steps: and setting a long-machine control instruction of the unmanned aerial vehicle and an expected formation interval, and establishing a compact formation mathematical model.
Step two: and inputting the control instruction of the long-distance unmanned aerial vehicle and the expected formation distance into an artificial potential field controller, and calculating the ideal state of the unmanned aerial vehicle formation in the next step.
Step three: and calculating the control quantity of the bureaucratic machines by utilizing an improved pigeon swarm optimization algorithm.
Step four: the control quantity of the bureaucratic plane is input into a tight formation model of the bureaucratic plane to calculate the next state quantity of the bureaucratic plane.
Step five: and repeating the second step to the fourth step until the simulation duration.