Mitigating mechanical vibrations caused by a fan in a computer system
View Patent ↗One embodiment provides a system that mitigates vibrations caused by cooling fans in a computer system. More specifically, the system includes a cooling fan mechanically coupled to the chassis of the computer system, wherein vibrations generated by the cooling fan are coupled to the chassis. The system also includes an actuation mechanism that creates a relative displacement between the cooling fan and the chassis when a control signal is applied to the actuation mechanism. The system additionally includes a detection mechanism which detects the relative displacement and generates a feedback signal which represents the relative displacement. The system further includes a control signal generation mechanism which converts the feedback signal into the control signal, which is subsequently applied to the actuation mechanism. When the control signal is applied to the actuation mechanism, the relative displacement between the cooling fan and the chassis vibrationally decouples the cooling fan from the chassis.
1. A system that mitigates vibrations caused by cooling fans in a computer system, comprising:
a cooling fan mechanically coupled to the chassis of the computer system, wherein vibrations generated by the cooling fan are coupled to the chassis;
an actuation mechanism configured to create a relative displacement between the cooling fan and the chassis when a control signal is applied to the actuation mechanism;
a detection mechanism configured to detect the relative displacement and generate a feedback signal which represents the relative displacement; and
a control-signal-generation mechanism configured to convert the feedback signal into the control signal, which is subsequently applied to the actuation mechanism;
wherein the control signal is generated so that the relative displacement between the cooling fan and the chassis vibrationally decouples the cooling fan from the chassis.
2. The system of claim 1 , wherein the actuation mechanism comprises:
a first electromagnet embedded in the cooling fan; and
a second electromagnet embedded in the chassis and located in proximity to the first electromagnet, wherein the first electromagnet and the second electromagnet form an electromagnetic suspension (EMS) across the interface between the cooling fan and the chassis,
wherein when subjected to the control signal, the first and second electromagnets cause magnetic levitation to vibrationally decouple the cooling fan from the chassis.
3. The system of claim 1 , wherein the detection mechanism comprises:
a first position sensor embedded in the cooling fan configured to detect the position of the cooling fan; and
a second position sensor embedded in the chassis configured to detect the position of the chassis.
4. The system of claim 3 , wherein the first and second position sensors are accelerometers, wherein each accelerometer is configured to measure both position and trajectory signals.
5. The system of claim 1 , wherein the control-signal-generation mechanism is a servomechanism controller.
6. The system of claim 1 , wherein the feedback signal includes both position signals and trajectory signals associated with the cooling fan and the chassis.
7. The system of claim 1 , wherein the relative displacement between the cooling fan and the chassis decouples the vibrational decoupling between the cooling fan and one or more hard-disk drives (HDDs) mechanically coupled to the chassis.
8. The system of claim 2 , wherein the accelerometers can be:
uni-axial accelerometers;
bi-axial accelerometers; and
tri-axial accelerometers.
9. The system of claim 1 , wherein the actuation mechanism is configured to create the relative displacement between the cooling fan and the chassis as:
a one-dimensional displacement;
a two-dimensional displacement; or
a three-dimensional displacement.
10. A method that mitigates vibrations caused by cooling fans in a computer system, comprising:
creating a relative displacement between a cooling fan and a chassis of the computer system using an actuation mechanism by applying a control signal to the actuation mechanism;
detecting the relative displacement and generating a feedback signal which represents the relative displacement; and
converting the feedback signal into the control signal, which is applied to the actuation mechanism,
wherein the control signal is generated so that the relative displacement between the cooling fan and the chassis vibrationally decouples the cooling fan from the chassis.
11. The method of claim 10 , wherein the actuation mechanism comprises:
a first electromagnet embedded in the cooling fan; and
a second electromagnet embedded in the chassis and located in proximity to the first electromagnet, wherein the first electromagnet and the second electromagnet form an electromagnetic suspension (EMS) across the interface between the cooling fan and the chassis,
wherein when subjected to the control signal, the first and second electromagnets cause magnetic levitation to vibrationally decouple the cooling fan from the chassis.
12. The method of claim 10 , wherein detecting the relative displacement involves:
using a first position sensor embedded in the cooling fan to detect the position of the cooling fan; and
using a second position sensor embedded in the chassis to detect the position of the chassis.
13. The method of claim 12 , wherein the first and second position sensors are accelerometers, wherein each accelerometer is configured to measure both position and trajectory signals.
14. The method of claim 10 , wherein the method further comprises using a servomechanism controller to convert the feedback signal into the control signal.
15. The method of claim 10 , wherein the feedback signal includes both position signals and trajectory signals associated with the cooling fan and the chassis.
16. The method of claim 10 , wherein the relative displacement between the cooling fan and the chassis vibrationally decouples the cooling fan from one or more hard-disk drives (HDDs) which are mechanically coupled to the chassis.
17. The method of claim 11 , wherein the accelerometers can be:
uni-axial accelerometers;
bi-axial accelerometers; and
tri-axial accelerometers.
18. The method of claim 10 , wherein creating the relative displacement between the cooling fan and the chassis involves creating:
a one-dimensional displacement;
a two-dimensional displacement; or
a three-dimensional displacement.
19. An apparatus that mitigates vibrations caused by cooling fans in a computer system, comprising:
a cooling fan mechanically coupled to the chassis of the computer system, wherein vibrations generated by the cooling fan are coupled to the chassis;
an actuation mechanism coupled to the cooling fan and configured to create a relative displacement between the cooling fan and the chassis when a control signal is applied to the actuation mechanism;
a detection mechanism configured to detect the relative displacement and generate a feedback signal which represents the relative displacement; and
a control-signal-generation mechanism configured to convert the feedback signal into the control signal, which is subsequently applied to the actuation mechanism;
wherein the control signal is generated so that the relative displacement between the cooling fan and the chassis vibrationally decouples the cooling fan from the chassis.
20. The apparatus of claim 19 , wherein the actuation mechanism comprises:
a first electromagnet embedded in the cooling fan; and
a second electromagnet embedded in the chassis and located in proximity to the first electromagnet, wherein the first electromagnet and the second electromagnet form an electromagnetic suspension (EMS) across the interface between the cooling fan and the chassis,
wherein when subjected to the control signal, the first and second electromagnets cause magnetic levitation to vibrationally decouple the cooling fan from the chassis.