Summary of the invention
The objective of the invention is in order to solve the optimized algorithm of existing satellite cost optimization method employing based on gradient information, this algorithm requires high to the continuity of a function, convergence is slow, stability can not be guaranteed, easily be absorbed in local optimum point, the problem that counting yield is low, provide a kind of cost optimization of moonlet based on normal cloud model method for designing.
A kind of cost optimization of moonlet based on normal cloud model method for designing of the present invention realizes by following steps:
Step 1, set up moonlet cost C Optimized model: moonlet cost C comprises the cost C of satellite system
s, ground system cost C
gWith launch cost C
f, use C=C
s+ C
g+ C
fCalculate;
Step 2, set the optimal design variable of moonlet cost C: the optimal design variable of moonlet cost C comprises seven optimal design variablees altogether, is respectively the bottom surface radius, satellite altitude, the type of solar cell, type and the duty cycle of accumulator of charge-coupled device camera focal length, orbit altitude, cylindrical shape satellite;
Step 3, seven optimal design variablees in step 2 are carried out the initialization assignment: each particle p
iExpression, the population scale is elected 30 as, generates at random each particle p
iInitial position
And initial velocity
Wherein
In formula
With
The bottom surface radius, satellite altitude, the type of solar cell, the type of accumulator and the initial value of duty cycle that represent respectively charge-coupled device camera focal length, orbit altitude, cylindrical shape satellite, wherein
In formula
With
Expression respectively
With
Corresponding speed initial value,
Utilize two pairs of population of formula one and formula to carry out the initialization assignment:
Formula one:
Formula two:
In formula one and formula two, S
1And S
2The random number between 0,1, x
minThe lower limit of design variable value, x
maxIt is the upper limit of design variable value;
Each particle p
iSelf optimal location L
iRepresent L
iInitial value
The optimal location of whole population particle represents with G, the initial value G of G
0According to following step assignment:
A, calculating population are that 30 particles are at each particle self optimal location
Corresponding satellite cost
B, 30 moonlet costs of comparison
Size, filter out wherein minimum moonlet cost, suppose that minimum moonlet cost is
The particle corresponding with it is p
m, corresponding particle p
mSelf optimal location be
Step 4, suppose that optimized algorithm completed k (k 〉=1) step, below calculate the speed in the k+1 step of each particle:
Suppose that algorithm calculates k (k 〉=1) during the step, each the particle p that has obtained
iSelf optimal location be
The optimal location of population integral body is G
k, each particle p
iPosition when k goes on foot
For:
Speed
For:
When k+1 goes on foot, each particle p
iIn the k+1 speed in step
Calculate according to formula three, four, five:
Formula three:
Formula four:
Formula five:
Parameter ω in formula three is inertial coefficient, c
1And c
2For confidence factor, inertial coefficient ω span is [0.8,1.2], confidence factor c
1And c
2Span be [0,2];
In the k step, by the particle p of cloud model generation
iCurrent location
With respect to it self current optimal location
Relative distance;
In the k step, by the particle p of cloud model generation
iCurrent location
Optimal location G with respect to whole population
kRelative distance, E
nThe entropy coefficient of cloud model, H
eThe super entropy coefficient of cloud model, E in optimizing process
nAnd H
eAll get the constant greater than zero, its E
nAnd H
eValue need to meet formula six:
Formula six:
Normal cloud model cloud (E
x, E
n, H
e) computing method as follows:
Formula seven: E '
n=randn (E
n, H
e)
Formula eight: cloud (E
x, E
n, H
e)=randn (E
x, E '
n)
Wherein, E '
nFor the intermediate variable in computation process, randn (E
n, H
e) expression generation E
nFor expectation, H
eFor variance with normal random number; Randn (E
x, E '
n) represent to generate with E '
nFor expectation, H
eFor variance with normal random number;
Step 5, the speed of utilizing particle k+1 to go on foot
Position while with k, going on foot
Calculate the position in each particle k+1 step
Utilize present speed
With nine positions of upgrading each particle by formula, original position
Formula nine:
Step 6, calculating k+1 go on foot each particle p
iSelf optimal location
Optimal location G with population integral body
k+1:
Each particle p
iSelf optimal location
By formula ten calculate:
Formula ten:
The optimal location G of population integral body
k+1Computation process as follows:
Calculating k+1 each particle self optimal location during the step
Corresponding moonlet cost
Filter out wherein minimum moonlet cost, suppose that minimum moonlet cost is
Corresponding optimal location is
G
k+1By formula 11 calculate:
Formula 11
The optimal location G of step 7, comparison k+1 step population integral body
k+1Moonlet cost C (G
k+1) with the optimal location G of k step population integral body
kMoonlet cost C (G
k) poor absolute value: if | C (G
k+1)-C (G
k) |<0.01, algorithm is restrained, and optimizes and finishes, G
k+1The optimum solution of trying to achieve exactly, if | C (G
k+1)-C (G
k) | 〉=0.01, not convergence of algorithm, the G that the k+1 step is asked
k+1Not optimum solution, come back to step 4,, according to step 4~step 6, obtain according to k+1 step
And G
k+1The calculating k+2 step
And G
k+2, until the absolute value of difference of moonlet cost corresponding to population optimal locations that meets adjacent two steps is less than 0.01.
The present invention has following beneficial effect:
The present invention is directed to this structure of satellite cost Optimized model, particle swarm optimization algorithm based on normal cloud model has been proposed, when having solved in the satellite cost optimal design hybrid variable that not only comprises continuous variable but also comprise discrete variable and optimize convergence is slow, the problem that precision is not high.The inventive method is to build on the basis of normal cloud model, has inherited the determinacy and the characteristic that randomness merges mutually of cloud model, has improved speed of convergence and the Global Optimality of optimized algorithm, and is faster than traditional algorithm convergence based on gradient information, precision is high.
Embodiment
Embodiment one: present embodiment realizes by following steps:
Step 1, set up moonlet cost C Optimized model: moonlet cost C comprises the cost C of satellite system
s, ground system cost C
gWith launch cost C
f, use C=C
s+ C
g+ C
fCalculate;
Step 2, set the optimal design variable of moonlet cost C: the optimal design variable of moonlet cost C comprises seven optimal design variablees altogether, is respectively the bottom surface radius, satellite altitude, the type of solar cell, type and the duty cycle of accumulator of charge-coupled device camera focal length, orbit altitude, cylindrical shape satellite;
Step 3, seven optimal design variablees in step 2 are carried out the initialization assignment: each particle p
iExpression, the population scale is elected 30 as, generates at random each particle p
iInitial position
And initial velocity
Wherein
In formula
With
The bottom surface radius, satellite altitude, the type of solar cell, the type of accumulator and the initial value of duty cycle that represent respectively charge-coupled device camera focal length, orbit altitude, cylindrical shape satellite, wherein
In formula
With
Expression respectively
With
Corresponding speed initial value,
Utilize two pairs of population of formula one and formula to carry out the initialization assignment:
Formula one:
Formula two:
In formula one and formula two, S
1And S
2The random number between 0,1, x
minThe lower limit of design variable value, x
maxIt is the upper limit of design variable value;
Each particle p
iSelf optimal location L
iRepresent L
iInitial value
The optimal location of whole population particle represents with G, the initial value G of G
0According to following step assignment:
A, calculating population are that 30 particles are at each particle self optimal location
Corresponding satellite cost
B, 30 moonlet costs of comparison
Size, filter out wherein minimum moonlet cost, suppose that minimum moonlet cost is
The particle corresponding with it is p
m, corresponding particle p
mSelf optimal location be
Step 4, suppose that optimized algorithm completed k (k 〉=1) step, below calculate the speed in the k+1 step of each particle:
Suppose that algorithm calculates k (k 〉=1) during the step, each the particle p that has obtained
iSelf optimal location be
The optimal location of population integral body is G
k, each particle p
iPosition when k goes on foot
For:
Speed
For:
When k+1 goes on foot, each particle p
iIn the k+1 speed in step
Calculate according to formula three, four, five:
Formula three:
Formula four:
Formula five:
Parameter ω in formula three is inertial coefficient, c
1And c
2For confidence factor, inertial coefficient ω span is [0.8,1.2], confidence factor c
1And c
2Span be [0,2];
In the k step, by the particle p of cloud model generation
iCurrent location
With respect to it self current optimal location
Relative distance;
In the k step, by the particle p of cloud model generation
iCurrent location
Optimal location G with respect to whole population
kRelative distance, E
nThe entropy coefficient of cloud model, H
eThe super entropy coefficient of cloud model, E in optimizing process
nAnd H
eAll get the constant greater than zero, its E
nAnd H
eValue need to meet formula six:
Formula six:
Normal cloud model cloud (E
x, E
n, H
e) computing method as follows:
Formula seven: E '
n=randn (E
n, H
e)
Formula eight: cloud (E
x, E
n, H
e)=randn (E
x, E '
n)
Wherein, E '
nFor the intermediate variable in computation process, randn (E
n, H
e) expression generation E
nFor expectation, H
eFor variance with normal random number; Randn (E
x, E '
n) represent to generate with E '
nFor expectation, H
eFor variance with normal random number;
Step 5, the speed of utilizing particle k+1 to go on foot
Position while with k, going on foot
Calculate the position in each particle k+1 step
Utilize present speed
With nine positions of upgrading each particle by formula, original position
Formula nine:
Step 6, calculating k+1 go on foot each particle p
iSelf optimal location
Optimal location G with population integral body
k+1:
Each particle p
iSelf optimal location
By formula ten calculate:
Formula ten:
The optimal location G of population integral body
k+1Computation process as follows:
Calculating k+1 each particle self optimal location during the step
Corresponding moonlet cost
Filter out wherein minimum moonlet cost, suppose that minimum moonlet cost is
Corresponding optimal location is
G
k+1By formula 11 calculate:
Formula 11
The optimal location G of step 7, comparison k+1 step population integral body
k+1Moonlet cost C (G
k+1) with the optimal location G of k step population integral body
kMoonlet cost C (G
k) poor absolute value: if | C (G
k+1)-C (G
k) |<0.01, algorithm is restrained, and optimizes and finishes, G
k+1The optimum solution of trying to achieve exactly, if | C (G
k+1)-C (G
k) | 〉=0.01, not convergence of algorithm, the G that the k+1 step is asked
k+1Not optimum solution, come back to step 4,, according to step 4~step 6, obtain according to k+1 step
And G
k+1The calculating k+2 step
And G
k+2, until the absolute value of difference of moonlet cost corresponding to population optimal locations that meets adjacent two steps is less than 0.01.