US 9,599,993 B2 · Three-dimensional manipulation of teams of quadrotors

Abstract

A system and method is described for controlling flight trajectories of at least two flying vehicles towards goal positions. The system includes at least two flying vehicles with onboard inertial measurement units for determining and updating orientation, angular velocities, position and linear velocities of the at least two flying vehicles, a motion capture system to detect current position and velocity of each of the at least two flying vehicles, and a base controller in communication with the motion capture system and in communication with the plurality of flying vehicles. The base controller calculates for each of the flying vehicles, at predetermined intervals of time, optimum trajectory paths using piece-wise smooth polynomial functions, applying weighting factors, and enforcing overlap constraints.

Claims37

Dependent claims

A trajectory generation method for controlling states of at least two vehicles towards goal positions and orientations, the method comprising the steps of:

determining orientation and angular velocities of the vehicles;
controlling the orientation and angular velocities of the vehicles by controlling at least one motor of the vehicles;
determining current position and velocity of each of the vehicles;
controlling the position and velocity of each of the vehicles by specifying the desired orientation and angular velocities and the net thrust required from the at least one motor;
calculating for each of the vehicles, at predetermined intervals of time, optimum trajectory paths by using piece-wise smooth polynomial functions, applying relative cost weighting factors among the at least two vehicles and enforcing inter-vehicle overlap constraints;
based on the calculated optimum trajectory paths, sending commands to each of the vehicles to control, individually, their state, causing such vehicles to follow the calculated optimum trajectory path while avoiding collisions;
and
updating current position and velocity of each of the vehicles.

5 more elements

A trajectory generation method for controlling states of at least two flying vehicles towards goal positions and orientations, the method comprising the steps of:

determining orientation and angular velocities of the flying vehicles;
controlling the orientation and angular velocities of the flying vehicles by controlling at least one motor of the flying vehicles;
determining current position and velocity of each of the flying vehicles;
controlling the position and velocity of each of the flying vehicles by specifying the desired orientation and angular velocities and the net thrust required from the at least one motor;
calculating for each of the flying vehicles, at predetermined intervals of time, optimum trajectory paths by using piece-wise smooth polynomial functions, applying weighting factors and enforcing overlap constraints;
based on the calculated optimum trajectory paths, sending commands to each of the flying vehicles to control, individually, their state, causing such flying vehicles to follow the calculated optimum trajectory path while avoiding collisions;
and
updating current position and velocity of each of the flying vehicles,
wherein calculating an optimum trajectory path for each flying vehicle comprises generating trajectories that smoothly transition through nw desired waypoints at specified times, tw while minimizing the integral of the krth derivative of position squared for nq quadrotors in accordance with the equation:
min
⁢
⁢
∑
q
=
1
n
q
⁢
⁢
∫
t
0
t
n
w
⁢


ⅆ
k
r
⁢
r
T
q
ⅆ
t
k
r


2
⁢
⁢
ⅆ
t
s
.
t
.
⁢
r
T
q
⁡
(
t
w
)
=
r
wq
,
w
=
0
,
…
⁢
,
n
w
;
∀
q
⁢
⁢
ⅆ
j
⁢
x
T
q
ⅆ
t
j
⁢

t
=
t
w
=
0
⁢
⁢
or
⁢
⁢
free
,
w
=
0
,
n
w
;
j
=
1
,
…
⁢
,
k
r
;
∀
q
⁢
⁢
ⅆ
j
⁢
y
T
q
ⅆ
t
j
❘
t
=
t
w
=
0
⁢
⁢
or
⁢
⁢
free
,
w
=
0
,
n
w
;
j
=
1
,
…
⁢
,
k
r
;
∀
q
⁢
⁢
ⅆ
j
⁢
z
T
q
ⅆ
t
j
❘
t
=
t
w
=
0
⁢
⁢
or
⁢
⁢
free
,
w
=
0
,
n
w
;
j
=
1
,
…
⁢
,
k
r
;
∀
q
where rTq=[xTq, yTq, zTq] represents the trajectory for quadrotor q and rwq represents desired waypoints for quadrotor q.

207 more elements

A trajectory generation method for controlling states of at least two flying vehicles towards goal positions and orientations, the method comprising the steps of:

determining orientation and angular velocities of the flying vehicles;
controlling the orientation and angular velocities of the flying vehicles by controlling at least one motor of the flying vehicles;
determining current position and velocity of each of the flying vehicles;
controlling the position and velocity of each of the flying vehicles by specifying the desired orientation and angular velocities and the net thrust required from the at least one motor;
calculating for each of the flying vehicles, at predetermined intervals of time, optimum trajectory paths by using piece-wise smooth polynomial functions, applying weighting factors and enforcing overlap constraints;
based on the calculated optimum trajectory paths, sending commands to each of the flying vehicles to control, individually, their state, causing such flying vehicles to follow the calculated optimum trajectory path while avoiding collisions;
and
updating current position and velocity of each of the flying vehicles,
further comprising providing collision avoidance among said at least two flying vehicles by modeling the flying vehicles as a rectangular prism oriented with a world frame with side lengths lx, ly, and lz that are large enough so that the flying machines may roll, pitch, and yaw to any angle and stay within the prism.

6 more elements

A system for controlling flight trajectories of at least two flying vehicles towards goal positions, the system comprising:

at least two flying vehicles with onboard inertial measurement units for determining and updating orientation, angular velocities, position and linear velocities of the at least two flying vehicles;
a motion capture system to detect current position and velocity of each of the at least two flying vehicles;
a base controller in communication with the motion capture system and in communication with the plurality of flying vehicles, said base controller calculating, for each of the flying vehicles, at predetermined intervals of time, optimum trajectory paths using piece-wise smooth polynomial functions, applying weighting factors, and enforcing overlap constraints, and based on the calculated optimum trajectory path, sending commands to each of the flying vehicles to control, individually, their state, causing said at least two flying vehicles to follow the calculated optimum trajectory path while avoiding collisions,
wherein said base controller calculates an optimum trajectory path for each flying vehicle by generating trajectories that smoothly transition through nw desired waypoints at specified times, tw while minimizing the integral of the krth derivative of position squared for nq quadrotors in accordance with the equation:
min
⁢
⁢
∑
q
=
1
n
q
⁢
⁢
∫
t
0
t
n
w
⁢


ⅆ
k
r
⁢
r
T
q
ⅆ
t
k
r


2
⁢
⁢
ⅆ
t
s
.
t
.
⁢
r
T
q
⁡
(
t
w
)
=
r
wq
,
w
=
0
,
…
⁢
,
n
w
;
∀
q
⁢
⁢
ⅆ
j
⁢
x
T
q
ⅆ
t
j
⁢

t
=
t
w
=
0
⁢
⁢
or
⁢
⁢
free
,
w
=
0
,
n
w
;
j
=
1
,
…
⁢
,
k
r
;
∀
q
⁢
⁢
ⅆ
j
⁢
y
T
q
ⅆ
t
j
❘
t
=
t
w
=
0
⁢
⁢
or
⁢
⁢
free
,
w
=
0
,
n
w
;
j
=
1
,
…
⁢
,
k
r
;
∀
q
⁢
⁢
ⅆ
j
⁢
z
T
q
ⅆ
t
j
❘
t
=
t
w
=
0
⁢
⁢
or
⁢
⁢
free
,
w
=
0
,
n
w
;
j
=
1
,
…
⁢
,
k
r
;
∀
q
where rTq=[xTq, yTq, zTq] represents the trajectory for quadrotor q and rwq represents desired waypoints for quadrotor q.

202 more elements

A system for controlling flight trajectories of at least two flying vehicles towards goal positions, the system comprising:

at least two flying vehicles with onboard inertial measurement units for determining and updating orientation, angular velocities, position and linear velocities of the at least two flying vehicles;
a motion capture system to detect current position and velocity of each of the at least two flying vehicles;
a base controller in communication with the motion capture system and in communication with the plurality of flying vehicles, said base controller calculating, for each of the flying vehicles, at predetermined intervals of time, optimum trajectory paths using piece-wise smooth polynomial functions, applying weighting factors, and enforcing overlap constraints, and based on the calculated optimum trajectory path, sending commands to each of the flying vehicles to control, individually, their state, causing said at least two flying vehicles to follow the calculated optimum trajectory path while avoiding collisions,
wherein said base controller further provides collision avoidance among said at least two flying vehicles by modeling the flying vehicles as a rectangular prism oriented with a world frame with side lengths lx, ly, and lz that are large enough so that the flying machines may roll, pitch, and yaw to any angle and stay within the prism.

1 more element

Dependencies are inferred from the claim text.

Three-dimensional manipulation of teams of quadrotors

Life of this patent

Three-dimensional manipulation of teams of quadrotors

Life of this patent

Abstract

Claims37