Summary of the invention
The present invention utilizes inadequate problem in order to solve fast reserve spacecraft flywheel ability, thereby a kind of optimization method of single shaft fast reserve spacecraft flywheel configuration is provided.
Single shaft fast reserve spacecraft flywheel configuration, includes five flywheels in this configuration, the axis of one of them flywheel and the axis of motorized shaft coincide, and other four flywheels are angle mount flywheel;
The angle of the rotating shaft of each angle mount flywheel and spacecraft maneuver axle is β, and β is real number; The angle of the projection of the rotating shaft of adjacent two angle mount flywheels on the non-plane of maneuver of spacecraft is 90 °, and the angle that is positioned at the projection of each the angle mount flywheel on the non-plane of maneuver of described spacecraft and the angle of spacecraft pitch axis and spacecraft yaw axis is 45 °.
The span of the angle β of the rotating shaft of each angle mount flywheel and spacecraft maneuver axle is:
The optimization method of single shaft fast reserve spacecraft flywheel configuration, it is realized by following steps:
Step 1, according to the angle β of the rotating shaft of each angle mount flywheel and spacecraft maneuver axle, structure flywheel installation matrix U:
Step 2, the installation matrix U obtaining according to the minimum power consumption of spacecraft and step 1, according to formula:
D=U
T(UU
T)
-1
The allocation matrix D of structure flywheel:
Step 3, the maximum torque of the non-motorized shaft of spacecraft is estimated, obtained the required matrix-vector T of the non-motorized shaft of spacecraft
nmax:
In formula: T
nmaxfor the required matrix-vector of the non-motorized shaft of spacecraft; T
ymaxfor the required maximum torque of pitch axis in axis of rolling mobile process, T
zmaxfor the required maximum torque of yaw axis in axis of rolling mobile process; K
pyproportionality coefficient for the PD controller of pitch axis; K
dydifferential coefficient for the PD controller of pitch axis; K
pzproportionality coefficient for the PD controller of yaw axis; K
dzdifferential coefficient for the PD controller of yaw axis; θ
maxmaxim (conventionally getting the departure higher limit of allowance) for pitch angle in mobile process; ω
ymaxmaxim (conventionally getting the departure higher limit of allowance) for pitch axis cireular frequency in mobile process; ψ
maxmaxim (conventionally getting the departure higher limit of allowance) for yaw angle in mobile process; ω
zmaxmaxim (conventionally getting the departure higher limit of allowance) for yaw axis cireular frequency in mobile process;
Step 4, the required matrix-vector T of the non-motorized shaft of spacecraft obtaining according to the allocation matrix D of the flywheel obtaining in step 2, step 3
nmaxthe maximum torque that can provide with each flywheel is T
wmaxobtain the optimum stagger angle β of motorized shaft moment
t;
The optimum stagger angle β of step 5, the motorized shaft moment that obtains according to step 4
t, according to described optimum stagger angle β
tsingle shaft fast reserve spacecraft flywheel configuration is adjusted, thereby realized the optimization of single shaft fast reserve spacecraft flywheel configuration.
The required matrix-vector T of the non-motorized shaft of spacecraft obtaining according to the allocation matrix D of the flywheel obtaining in step 2, step 3 described in step 4
nmaxthe maximum torque that can provide with each flywheel is T
wmaxobtain the optimum stagger angle β of motorized shaft moment
tconcrete grammar be:
The moment providing according to each flywheel is less than or equal to the principle of the moment upper limit of flywheel, obtains constraint inequality:
DT
cmax≤T
wmax
In formula: T
cmax=[T
xmaxt
ymaxt
zmax]
t, be the maximum instruction moment that five divided flywheels fit over satellite three axles;
In formula: T
wmaxthe array that the maximum torque value that can provide for each flywheel forms; On the same satellite of normal conditions, the maximum torque value of each flywheel is identical, its size T
wmaxrepresent.T
xmaxthe maximum torque that can provide at the axis of rolling for flywheel;
In above formula:
Make T
ymax+ T
zmax=T
y+z, by DT
cmax≤ T
wmaxlaunch, obtain:
Be reduced to:
According to:
T
xmax=T
wmax(1+4cos
2β) exist
inside the subtraction function about β,
?
inside the increasing function about β, and
it is inside subtraction function;
The optimum stagger angle β of motorized shaft moment
tvalue be below equation about the solution of β:
Beneficial effect: the present invention can make full use of fast reserve spacecraft flywheel ability, and flywheel configuration of the present invention has larger moment space in motorized shaft, is applicable to having the spacecraft of single shaft fast reserve ability; Meanwhile, optimization method of the present invention makes flywheel can provide maximum moment in motorized shaft direction, thereby improves the acceleration/accel of satellite; Optimization method of the present invention, is guaranteeing can to control the while to non-motorized shaft, makes the maneuverability of motorized shaft reach optimum, does not ignore the control of non-motorized shaft, is therefore more suitable for real satellite attitude control system.
The specific embodiment
The specific embodiment one, single shaft fast reserve spacecraft flywheel configuration, include five flywheels in this configuration, the axis of one of them flywheel and the axis of motorized shaft coincide, and other four flywheels are angle mount flywheel;
The angle of the rotating shaft of each angle mount flywheel and spacecraft maneuver axle is β, and β is real number; The angle of the projection of the rotating shaft of adjacent two angle mount flywheels on the non-plane of maneuver of spacecraft is 90 °, and the angle that is positioned at the projection of each the angle mount flywheel on the non-plane of maneuver of described spacecraft and the angle of spacecraft pitch axis and spacecraft yaw axis is 45 °.
The span of the angle β of the rotating shaft of each angle mount flywheel and spacecraft maneuver axle is:
As depicted in figs. 1 and 2, in figure, RW is flywheel to configuration result; Present embodiment actv. has utilized the ability of flywheel, can guarantee that non-motorized shaft is controlled to the while, makes the maneuverability of motorized shaft reach optimum, is not adding under the prerequisite of other actuating units, has shortened spacecraft maneuver required time.And flywheel configuration of the present invention has larger moment space in motorized shaft, be applicable to having the spacecraft of single shaft fast reserve ability.
The optimization method of the specific embodiment two, single shaft fast reserve spacecraft flywheel configuration, it is realized by following steps:
Step 1, according to the angle β of the rotating shaft of each angle mount flywheel and spacecraft maneuver axle, structure flywheel installation matrix U:
Step 2, the installation matrix U obtaining according to the minimum power consumption of spacecraft and step 1, according to formula:
D=U
T(UU
T)
-1
The allocation matrix D of structure flywheel:
Step 3, the maximum torque of the non-motorized shaft of spacecraft is estimated, obtained the maximum torque value T of the non-motorized shaft of spacecraft
nmax:
In formula: T
nmaxfor the required matrix-vector of the non-motorized shaft of spacecraft; T
ymaxfor the required maximum torque of pitch axis in axis of rolling mobile process, T
zmaxfor the required maximum torque of yaw axis in axis of rolling mobile process; K
pyproportionality coefficient for the PD controller of pitch axis; K
dydifferential coefficient for the PD controller of pitch axis; K
pzproportionality coefficient for the PD controller of yaw axis; K
dzdifferential coefficient for the PD controller of yaw axis; θ
maxmaxim (conventionally getting the departure higher limit of allowance) for pitch angle in mobile process; ω
ymaxmaxim (conventionally getting the departure higher limit of allowance) for pitch axis cireular frequency in mobile process; ψ
maxmaxim (conventionally getting the departure higher limit of allowance) for yaw angle in mobile process; ω
zmaxmaxim (conventionally getting the departure higher limit of allowance) for yaw axis cireular frequency in mobile process;
The maximum torque value T of step 4, the non-motorized shaft of spacecraft that obtains according to the allocation matrix D of the flywheel obtaining in step 2, step 3
nmaxthe maximum torque that can provide with each flywheel is T
wmaxobtain the optimum stagger angle β of motorized shaft moment
t;
The optimum stagger angle β of step 5, the motorized shaft moment that obtains according to step 4
t, according to described optimum stagger angle β
tsingle shaft fast reserve spacecraft flywheel configuration is adjusted, thereby realized the optimization of single shaft fast reserve spacecraft flywheel configuration.
The maximum torque value T of the non-motorized shaft of spacecraft obtaining according to the allocation matrix D of the flywheel obtaining in step 2, step 3 described in step 4
nmaxthe maximum torque that can provide with each flywheel is T
wmaxobtain the optimum stagger angle β of motorized shaft moment
tconcrete grammar be:
The moment providing according to each flywheel is less than or equal to the principle of the moment upper limit of flywheel, obtains constraint inequality:
DT
cmax≤T
wmax
In formula: T
cmax=[T
xmaxt
ymaxt
zmax]
t, be the maximum instruction moment that five divided flywheels fit over satellite three axles;
In formula: T
wmaxthe array that the maximum torque value that can provide for each flywheel forms; On the same satellite of normal conditions, the maximum torque value of each flywheel is identical, its size T
wmaxrepresent.T
xmaxthe maximum torque that can provide at the axis of rolling for flywheel;
In above formula,
Make T
ymax+ T
zmax=T
y+z, by DT
cmax≤ T
wmaxlaunch, obtain:
In formula: T
x+yit is an intermediate variable;
Be reduced to:
According to:
T
xmax=T
wmax(1+4cos
2β) exist
Inside the subtraction function about β,
?
Inside the increasing function about β, and
It is inside subtraction function;
The optimum stagger angle β of motorized shaft moment
tvalue be below equation about the solution of β:
The minimum power consumption of spacecraft described in step 2 is by formula:
Get minimum acquisition.
In formula, J
wfor the diagonal matrix of each Rotary Inertia of Flywheel composition,
it is the array that each flywheel angular acceleration forms.
In step 3, the maximum torque of the non-motorized shaft of spacecraft is carried out in estimation process, non-arbor is PD controller, and the form of estimation is:
Below adopt concrete parameter, implement configuration of the present invention and optimization method:
Steps A, determine that the moment of single flywheel maximum is T
wmax=0.2Nm;
Step B, write out the allocation matrix of satellite;
Step C, according to the value of control algorithm, obtain T
ymaxwith T
zmax: conventionally get:
K
py=K
pz=57.3
θ
max=ψ
max=0.01°=1.7452×10
-4rad
K
dy=K
dz=8×57.3=458.4
ω
ymax=ω
zmax=0.005°/s=8.726×10
-5rad/s
According to value above and:
Obtain T
ymaxwith T
zmaxvalue;
Step D, determine the required maximum torque T of the non-motorized shaft of satellite
ymax=T
zmax=0.05Nm;
Step e, determine the optimum stagger angle of moment, for different configuration modes, resulting result is not identical, and particular case is as follows:
Flywheel configuration of four angle mounts+motorized shaft: this configuration mode need to solve take the equation that β is equation:
Substitution T
ymax=T
zmax=0.05Nm, T
wmax=0.2Nm, can be in the hope of β
t=42.4 °, T now
xmaxmaxim be 0.635Nm, matrix is installed:
Optimization method in present embodiment makes flywheel can provide maximum moment in motorized shaft direction, thereby improves the acceleration/accel of satellite; The optimization method of present embodiment, is guaranteeing can to control the while to non-motorized shaft, makes the maneuverability of motorized shaft reach optimum, does not ignore the control of non-motorized shaft, is therefore more suitable for real satellite attitude control system.