Actuator including mechanism for converting rotary motion to linear motion
View Patent ↗An active vibration control device is provided that is configured to control the position of a body relative to a reference frame. The control device includes sensors that provide input signals corresponding to movement of the body in at least one direction, a rotary rotary actuator configured to control the position of the body, and four-bar linkage connecting the rotary rotary actuator to the body. The linkage converts the rotary motion output from the rotary actuator into a linear motion of the body. The controller, based on the input signals from the reference frame sensors, provides control signals to the rotary rotary actuator which acts through the linkage to position the body in the at least one direction relative to the position of the reference frame.
1. An active vibration control device configured to control the position of a body, the device comprising:
at least one sensor configured to provide input signals corresponding to movement of the body in at least one direction;
a rotary actuator configured to control the position of the body, and
a linkage comprising a pivotably-joined link connecting the rotary actuator to the body, the linkage connected to and driven by the rotary actuator, the linkage configured to convert rotary motion output from the rotary actuator into a linear motion of the body,
a controller which, based on the input signals from the at least one sensor, provides control signals to the rotary actuator which acts through the linkage to position the body in the at least one direction,
wherein the linkage is configured to convert the rotary motion of an output shaft of the rotary actuator into linear motion such that the torque required by the rotary actuator to produce a constant force at the body is substantially constant over a range of displacement of the body of at least four inches.
2. The active vibration control device of claim 1 wherein the torque required by the rotary actuator to provide a constant force at the body is substantially constant over a 100 degree angular rotation of an output shaft of the rotary actuator.
3. An active vibration control device configured to control the position of a body, the device comprising:
at least one sensor configured to provide input signals corresponding to movement of the body in at least one direction;
a rotary actuator configured to control the position of the body, and
a linkage comprising a pivotably-joined link connecting the rotary actuator to the body, the linkage connected to and driven by the rotary actuator, the linkage configured to convert rotary motion output from the rotary actuator into a linear motion of the body,
a controller which, based on the input signals from the at least one sensor, provides control signals to the rotary actuator which acts through the linkage to position the body in the at least one direction,
wherein the linkage is connected to an output shaft of the rotary actuator on one side of the rotary actuator, and the device further comprises a second linkage connected to the output shaft of the rotary actuator on a side of the rotary actuator opposed to the one side.
4. An active vibration control device configured to control the position of a body, the device comprising:
at least one sensor configured to provide input signals corresponding to movement of the body in at least one direction;
a rotary actuator configured to control the position of the body, and
a linkage comprising a pivotably-joined link connecting the rotary actuator to the body, the linkage connected to and driven by the rotary actuator, the linkage configured to convert rotary motion output from the rotary actuator into a linear motion of the body,
a controller which, based on the input signals from the at least one sensor, provides control signals to the rotary actuator which acts through the linkage to position the body in the at least one direction
wherein a rotor of the rotary actuator is prevented from rotating beyond a predetermined range.
5. The active vibration control device of claim 4 wherein the controller prevents the rotor from rotating beyond the predetermined range.
6. The active vibration control device of claim 4 wherein a mechanical stop member is provided to prevent the rotor from rotating beyond the predetermined range.
7. An active vibration control device configured to control the position of a body, the device comprising:
at least one sensor configured to provide input signals corresponding to movement of the body in at least one direction;
a rotary actuator configured to control the position of the body, and
a linkage comprising a pivotably-joined link connecting the rotary actuator to the body, the linkage configured to convert rotary motion output from the rotary actuator into a linear motion of the body,
a controller which, based on the input signals from the at least one sensor, provides control signals to the rotary actuator which acts through the linkage to position the body in the at least one direction, wherein;
the body comprises a vehicle seat, the seat is disposed in a vehicle, and the rotary actuator is disposed between a floor in the vehicle and the seat,
wherein the linkage is connected to an output shaft of the rotary actuator on one side of the rotary actuator, and the device further comprises a second linkage connected to the output shaft of the rotary actuator on a side of the rotary actuator opposed to the one side.
8. An active vibration control device configured to control the position of a body, the device comprising:
at least one sensor configured to provide input signals corresponding to movement of the body in at least one direction;
a rotary actuator configured to control the position of the body, and
a linkage comprising a pivotably-joined link connecting the rotary actuator to the body, the linkage configured to convert rotary motion output from the rotary actuator into a linear motion of the body,
a controller which, based on the input signals from the at least one sensor, provides control signals to the rotary actuator which acts through the linkage to position the body in the at least one direction, wherein;
the body comprises a vehicle seat, the seat is disposed in a vehicle, and the rotary actuator is disposed between a floor in the vehicle and the seat,
wherein a rotor of the rotary actuator is prevented from rotating beyond a predetermined range.
9. The active vibration control device of claim 8 wherein the controller prevents the rotor from rotating beyond the predetermined range.
10. The active vibration control device of claim 8 wherein a mechanical stop member is provided to prevent the rotor from rotating beyond the predetermined range.