High speed actuation systems
A system can include a spinning structure configured to spin in operation, and at least one mass operatively connected to spinning structure to rotate about a spin axis with the spinning structure. The at least one mass can be configured to be moved relative to the spinning structure during a spin of the spinning structure. The system can include an actuation system configured to move the at least one mass relative to the spinning structure. The actuation system can be configured to move the at least one mass while the spinning structure is spinning to use the spin of the spinning structure to induce a precession torque on the spinning structure. The actuation system can be configured to synchronize actuation motion of the at least one mass to the spin of the spinning structure such that the induced precession torque is in a desired direction.
1 . A system, comprising:
a spinning structure configured to spin in operation;
a mass operatively connected to the spinning structure, the mass configured to rotate with the spinning structure about a spin axis of the spinning structure, wherein the mass is configured to be moved relative to the spinning structure during a spin of the spinning structure; and
an actuation system configured to move the mass relative to the spinning structure, wherein the actuation system is further configured to control movement of the mass and to synchronize the movement of the mass to a rotation angle of the spinning structure, thereby inducing a synchronous precession torque to the spinning structure in a desired direction.
2 . The system of claim 1 , further comprising a spring connecting the mass to the spinning structure.
3 . The system of claim 2 , wherein a natural frequency of the spring and the mass is selected to match a frequency of the spin.
4 . The system of claim 1 , wherein the mass is offset from the spin axis by a distance.
5 . The system of claim 4 , wherein the mass is configured to be moved axially with respect to the spinning structure.
6 . The system of claim 4 , wherein the mass is configured to be moved radially with respect to the spinning structure.
7 . The system of claim 1 , wherein the actuation system includes a piezoelectric actuator operatively connected to the mass to move the mass.
8 . The system of claim 1 , wherein the spinning structure is or includes an aerodynamic body, wherein the mass is disposed within the aerodynamic body.
9 . The system of claim 8 , wherein the precession torque changes an angle of attack of the aerodynamic body in-flight to produce an aerodynamic effect to modify a flight path of the aerodynamic body.
10 . The system of claim 9 , wherein the aerodynamic body is a projectile or is a portion of a projectile.
11 . The system of claim 9 , wherein the mass is or includes a payload of the projectile.
12 . The system of claim 11 , wherein the payload is a warhead.
13 . The system of claim 1 , wherein the actuation system includes a controller configured to determine a timing and amplitude to move the mass as a function of the rotation angle of the spinning structure.
14 . The system of claim 12 , wherein the controller is configured to output a command to cause motion of the mass such that the mass is phased and/or timed with the rotation angle of the projectile to induce an internal torque to correct a projectile flight toward a desired direction.
15 . The system of claim 12 , wherein the controller is configured to output the command once per multiple revolutions of the spinning structure to cause actuation of the mass once per multiple revolutions of the spinning structure to reduce energy consumption.
16 . The system of claim 12 , wherein the spin has a frequency greater than 10 Hz.
17 . The system of claim 16 , wherein the controller is configured to:
receive rotational position information and/or location information; and
determine the command as a function of the received rotational position information and/or location information to cause a motion of the mass that results in a desired movement of the spinning structure.
18 . A projectile, comprising:
a spinning structure configured to spin in-flight;
a mass operatively connected to spinning structure to rotate with the spinning structure about a spin axis of the structure, wherein the mass is configured to be moved relative to the spinning structure during a spin of the spinning structure; and
an actuation system configured to move the mass relative to the spinning structure, wherein the actuation system is further configured to control movement of the mass and to synchronize the movement of the mass to a rotation angle of the spinning structure, thereby inducing a synchronous precession torque to the spinning structure in a desired direction to steer the projectile.
19 . A non-transitory computer readable medium, comprising computer executable instructions configured to cause a computer to perform a method, the method comprising:
receiving or determining a rotation angle and/or rate of spin of a mass attached to a spinning structure;
determining a timing and amplitude to move the mass as a function of the rotation angle and/or rate of spin to induce a synchronous precession torque on the spinning structure to steer the spinning structure in a desired direction; and
outputting a command to an actuator to move the mass and to synchronize the movement of the mass to a rotation angle of the spinning structure.
20 . The non-transitory computer readable medium of claim 19 , wherein outputting the command includes outputting a command to cause motion of the mass such that the mass is phased and/or timed with the rotation angle of the spinning structure to correct a flight path of the spinning structure toward a desired location.