Abstract:
Disclosed is a system for suppressing vibration and noise mitigation in structures such as blades in turbomachinery. The system includes flexible piezoelectric patches which are secured on or imbedded in turbomachinery blades which, in one embodiment, comprises eight (8) fan blades. The system further includes a capacitor plate coupler and a power transfer apparatus, which may both be arranged into one assembly, that respectively transfer data and power. Each of the capacitive plate coupler and power transfer apparatus is configured so that one part is attached to a fixed member while another part is attached to a rotatable member with an air gap therebetween. The system still further includes a processor that has 16 channels, eight of which serve as sensor channels, and the remaining eight, serving as actuation channels. The processor collects and analyzes the sensor signals and, in turn, outputs corrective signals for vibration/noise suppression of the turbine blades.

Description:
ORIGIN OF INVENTION 
     The invention described herein was made in the performance of work under a NASA contract and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, Public Law 85-568 (72 Stat. 435; 42 U.S.C.2457). 
    
    
     CROSS-REFERENCE TO RELATED APPLICATIONS 
     None 
     FIELD OF THE INVENTION 
     The present invention relates to a system for suppressing vibrations in structures of turbomachinery and, more particularly, to a system for suppressing vibrations in turbomachinery blades by utilizing piezoelectric elements that are mounted on or in the blades and are activated and monitored by wireless devices including inductive and capacitive couplers that are attached to the rotor hub of the turbomachinery. 
     Blade vibration in turbomachinery is a nettlesome problem that demands an effective solution. Vibration in turbomachinery can cause blade failures and leads to the use of heavier, thicker blades that result in lower aerodynamic efficiency and increased noise of turbomachinery, Efficient engine operation necessitates minimal disturbance to the gas flowing across the turbine blades in any effort to mitigate blade vibration. The problem of turbomachinery blade vibration represents a serious safety issue. Prolonged, excessive vibration can cause blade failure, sometimes resulting in accidents. Past attempts at an effective solution to this vibration problem have limitations, due largely to issues of hardware impracticality. 
     One previous approach, called passive damping, may require heavy electronics incorporating a large coil and the use of unreliable, bulky slip ring technology having brushes serving as connecting means to a rotating element and which requires cooling and may prove unreliable and problematic over time. Another approach uses special mechanical devices or damping materials to dampen specific vibration frequencies in the blades, but even this approach has drawbacks due to the condition wherein the material adds weight to the turbomachinery blades. Further approaches utilize sensing and activating elements, such as piezoelectric devices, mounted in or on turbomachinery rotating blades, but the monitoring of these sensing and activating elements requires relatively complex circuit arrangements, sometimes referred to as wireless systems, of transmitter and receivers that are limited to providing excitation to the activating elements from a power source that is free from rotation. It is desired to provide a system for suppressing vibrations in a turbomachinery blade that is not plagued by the prior art drawbacks. 
     OBJECTS OF THE INVENTION 
     It is a primary object of the present invention to provide a system for detecting and suppressing vibrations in a turbomachine component, such as a fan compressor or turbine blade, that is free of slip ring technology. 
     It is another object of the present invention to provide a system for detecting and suppressing deleterious vibrations in fan blades that are free of relatively heavy electronics incorporating large coils or other bulky devices that unnecessary add weight to the fan blades, while undesirably interfering with air flowing across the turbine blade. 
     Further, it is still another object of the present invention to provide a system for detecting and suppressing deleterious vibrations in a fan compressor or turbine blades that supply excitation to sensing elements to measure vibrations by way of a rotating element of a wireless arrangement, so as to be free of the requirement of receiving the excitation for activating elements by way of stationary elements. 
     SUMMARY OF THE INVENTION 
     The present invention provides a system for suppressing vibrations in at least one fan blade of a turbomachine having a rotor hub and being located near a stationary unit. The system comprises; a) at least one actuator having an input and located on the at least one fan blade, the input of the actuator receiving a signal which causes deformation of the actuator; b) at least one sensor having an input and an output and located on the at least one fan blade, the input of the sensor generating a signal representative of the vibrations occurring on the at least one fan blade, the output of the sensor providing a signal representative of the vibrations. The system further comprises; c) at least one analog to digital converter located on the rotor hub receiving the output of the at least one sensor and providing a digital output signal representative thereof; d) a capacitive plate coupler having first and second stages spaced apart by a first predetermined distance with the first stage being located on the rotor hub and the second stage being located on the stationary unit, the first stage having an input and an output and the second stage having an input and output, the capacitive plate coupler having its first stage input receiving the output of the at least one analog to digital converter and providing a representative signal thereof at its output of its first stage. The system further still comprises; at least one digital to analog converter located on the stationary unit and receiving the output of the first stage of the capacitor plate coupler; f) a processor having operating routines for suppressing vibrations in the at least one fan blade, the processor further having first and second inputs and an output, the first input of the processor receiving the output of the at least one digital to analog converter located on the stationary unit, the operating routines of the processor providing an output signal to suppress the vibrations of the at least one fan blade. The system further includes; g) at least one analog to digital converter located on the stationary unit and receiving the output signal of the processor and providing a representative output therefrom that is routed to the input of the second stage of the capacitive plate coupler and providing a representative signal thereof of its output of its second stage; h) at least one digital to analog converter located on the rotor hub and receiving the output at the second stage of the capacitive plate coupler and providing a representative output thereof; i) a power supply located on the stationary unit and having at least one output. The system still further comprises; j) an inductive power transfer apparatus having first and second stages with the first stage thereof located at the stationary unit and the second stage thereof located at the rotor hub, the first and second stages being spaced apart by the first predetermined distance, the first stage of the inductive power transfer element being connected to the output of the power supply and providing a representative output thereof at the second stage of the inductive power transfer apparatus, the second stage being connected to power supplies located on the rotor hub. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of the system of the present invention that suppresses deleterious vibrations of a fan blade of a turbomachine; 
         FIG. 2  is a schematic drawing of a capacitive plate coupler comprised of first and second stages; 
         FIG. 3  is a schematic drawing of an inductive power transfer apparatus comprised of first and second stages; and 
         FIG. 4  illustrates the sequence of operations of the processor of the present invention for collecting and analyzing input sensor signals and, in turn, for providing correcting actuating signals to suppress deleterious vibrations experienced by a fan blade of the turbomachine. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is directed to the field of turbomachineiy, such as jet engines or electric power generators, wherein the system of the present invention suppresses destructive vibrations in turbomachinery components, such as turbine or fan compressor blades. 
     The present invention preferably utilizes piezoelectric elements which deliver a voltage when deformed, or conversely, which changes in shape when a voltage is applied to them. The piezoelectric elements that deliver a voltage when deformed serve as a sensor of the present invention and, conversely, the piezoelectric elements which change in shape when a voltage is applied serves as an actuator of the present invention. 
     The present invention provides an integrated system for non-contact transmission between stationary and rotating components, wherein power is transferred by inductive linking and the data is coupled by capacitive coupling. The system provides a full-duplex serial communication link suitable for transporting bi-directional channel data in a serial digital form to and from an external computer and/or data processor. 
     In one embodiment, the system  10  of the present invention couples analog signal data, at a 20 KHz bandwidth, associated with sixteen channels with eight channels thereof associated with actuators and eight channels thereof associated with sensors, to and from eight fan blades of a turbomachine. The system  10  of the present invention may be further described with reference to the block diagram of  FIG. 1 . 
     The system  10  includes actuators  12   1  . . .  12   N  and sensors  14   1  . . .  14   N  that are mounted on or embedded in the fan blades  16   1  . . .  16   N . For the embodiment of  FIG. 1 , there are eight (8) fan blades  16   1  . . .  16   8 , each of which respectively has an actuator  12   1  . . .  12   8  and a sensor  14   1  . . .  14   8 . 
     As will be further described hereinafter, the actuators  12  operates upon the application of a voltage in the range of plus (+) to minus (−) 200 VDC which causes the deformation of the actuator  12  itself. The mounting of the actuators and the sensors on to the fan blade is accomplished by the use of high-strength adhesive, such as high temperature epoxy, known in the art. The embedding of the actuators and sensors into the respective fan blades is accomplished, for composite fan blades, by cutting out sections of composite plies, making up the composite fan blades, and replacing them with the actuator or sensor before curing the composite fan blade; or in the case of a metal fan blade, by machining a pocket, mounting the actuator or sensor within the pocket with high-strength adhesive, and then closing the pocket with a welded metal cover so as to restore the external blade shape. 
     Each of the sensors  14  has an input connected to the respective fan blade and an output which is connected to a rotor hub  20  by way of signal paths  22   1  . . .  22   8 , and, similarly, each of the actuators  12  is connected to the rotor hub of  20 , by way of signal path  24   1  . . .  24   8 . The signal paths  22   1  . . .  22   8  are preferably and respectively connected to drivers  25   1  . . .  25   8  which, in turn, are respectively connected to A/D converters  26   1  . . .  26   8 . The signal paths  24   1  . . .  24   8  are preferably and respectively connected to OP AMPS  28   1  . . .  28   8  which, in turn, are respectively connected to D/A converters  30   1  . . .  30   8 . 
     The drivers  25   1  . . .  25   8  are the conditioning circuits for the eight channels of analog data received from sensors  14   1  . . .  14   N . The eight channels of data provided by D/A converters  30   1  . . .  30   8  and OP AMP  28   1  . . .  28   8  are used to drive the actuators  12   1  . . .  12   8 . 
     The drivers  25   1  . . .  25   8  are analog current amplifiers which allow for the current output of the sensors  14   1  . . .  14   8  to be connected to an analog voltage compatible with A/D converters  26   1  . . .  26   8  both in source impedance and in amplitude. The output D/A voltages of D/A converters  30   1  . . .  30   8  are inputs to high power amplifiers of OP AMPS  28   1  . . .  28   8  which are capable of translating the low voltage output of the D/A&#39;s converters  30   1  . . .  30   8  into the high level (+−200V) DC signals needed to drive the actuators  12   1  . . .  12   8 . 
     The AD converters  26   1  . . .  26   8  supply output signals, via signal paths  34   1  . . .  34   8 , to a capacitor plate coupler  32  having an input stage  32 A and an output stage  32 B and to be further described hereinafter with reference to  FIG. 2 . Similarly, the D/A converters  30   1  . . .  30   8  receive an output signal from the capacitor plate coupler  32  by way of signal paths  36   1  . . .  36   8 . 
     The input stage  32 A is located on the rotor hub  20  whereas the output stage  32 B is located on the stationary base unit  38 . The input stage  32 A and the output stage  32 B are spaced apart by the first predetermined distance  40  which provide an air gap therebetween. The air gap  40  is from about 0.025 to about 0.030 inches. Similarly, the predetermined air gap  40  separates the input stage  42 A and the output stage  42 B of the inductive power transfer apparatus  42 , to be further described hereinafter with reference to  FIG. 3 . 
     The output stage  32 B of the capacitor plate coupler  32  provides output signals to D/A converters  44   1  . . .  44   8 , located on the stationary base unit  38 , via signal paths  46   1  . . .  46   8 , and, similarly, the output stage  32 B of the capacitor plate coupler  32  receives input signals from A/D converters  48   1  . . .  48   8 , also located on the stationary base unit  38 , via signal paths  50   1  . . .  50   8 . The D/A converters  44   1  . . .  44   8  supply input signals to a chip/processor  52 , via signal paths  54   1  . . .  54   8  and, similarly, the A/D converters  48   1  . . .  48   8  receive output signals from chip/processor  52 , via signal paths  56   1  . . .  56   8 . 
     For the embodiment shown in  FIG. 1 , the chip/processor  52  receives information from a personal computer (PC)  58 , via signal path  60 . However, in other embodiments, the PC  58  may directly receive information from the D/A converters  44   1  . . .  44   8  and transmit information directly to the A/D converters  48   1  . . .  48   8 . In further embodiments, the chip/processor  52  may be pre-programmed and act as a stand-alone device and not require any information from PC  58 . 
     The stationary base unit  38  has located thereon a DC power supply  62  which supplies power, signal path  64  to the input stage  42 A of the inductive power transfer apparatus  42  to be further discussed with reference to  FIG. 3 . The inductive power transfer apparatus  42 , in response to its received input signal, provides an output signal at its output stage  4213 , which is routed to a high voltage power supply  66 , via signal path  68  and to a low voltage power supply  70 , via signal path  72 . 
     Although not shown for the sake of clarity, the high voltage power supply  66  is routed to the OP AMPS  28   1  . . .  28   2  located on the rotor hub  20  and feeding the actuators  12   1  . . .  12   8 , whereas the low voltage power supply  70  is routed, also not shown for the sake of clarity, to all of the electronics located on the rotor hub  20  including the capacitor plate coupler  32  which may be further described with reference to  FIG. 2 . 
       FIG. 2  illustrates that the input stage  32 A is separated from the output stage  32 B by the predetermined distance  40  previously discussed with reference to  FIG. 1 . The input stage  32 A is comprised of an Application Specific Integrated Circuit (ASIC)  74 , a capacitor differential driver  76  having associated capacitor element  76 A and  76 B, and a capacitor differential receiver  78  having associated capacitor elements  78 A and  78 B, all arranged as shown in  FIG. 2 . The capacitive elements  76 A and  76 B are arranged to receive the output of differential driver  76  and are located on a first plate  32 A 1 , whereas capacitive elements  78 A and  78 B are arranged to provide an input signal to differential receiver  78  and are also located on the first plate  32 A 1 . 
     The elements  76 A,  76 B, and  76  receive the input to the first stage  32 A 1 , and capacitive elements  84 A and  84 B, to be described, receive the output of the first stage  32 A 1 . Conversely, capacitive elements  82 A and  82 B receive the input to the second stage  32 B 1  and capacitive elements  78 A and  78 B receive the output of the second stage  32 B 1 . 
     The output stage  32 B is comprised of the Applications Specific Integrated Circuit (ASIC)  74  also serving the input stage  32 A; a capacitor differential driver  82  having capacitive elements  82 A and  82 B, and a capacitor differential receiver  84  having associated capacitive elements  84 A and  84 B all arranged as shown in  FIG. 2 . The capacitive elements  82 A and  82 B are arranged to receive the output of differential driver  82  and are located on a second plate  32 B 1 , whereas capacitive elements  84 A and  84 B are arranged to provide an input signal to differential receiver  84  and are also located on the second plate  32 B 1 . 
     The first and second plates  32 A 1  and  32 B 1 , respectively, located on the input stage  32 A 1  and output stage  32 B 1 , separated by an air gap  40  from about 0.025 to about 0.030 inches, are arranged so as provide capacitive coupling therebetween and to transfer data, in a serial format, at a rate of about 50 KHz. 
     In operation, the capacitive plate coupler  32  essentially provides digital signal data paths which are minor images from each other. More particularly, the capacitive plate coupler  32  provides for eight (8) analog channels of data to be connected to high speed digital serial stream. The digital data stream is then capacitively driven across the air gap  40  of about 0.025 to about 0.030 inches, via capacitive differential driver  76  and differential receiver  84 . The serial steam is then decomposed into the eight (8) individual channel data by ASIC  74 , which is output through eight (8) each D/A converters  44   1  . . .  44   8  essentially “reconstructing” the input eight (8) analog channels received from A/D converters  26   1  . . .  26   8 . This process is run in both directions including capacitive differential driver  82  and differential receiver  78 ; hence you have sixteen (16) channels of digital signal data passed across the air gap  40  in both directions. 
     The process of collecting the data from the eight (8) A/D converters  48   1  . . .  48   8  converting the data into a single digital data stream and sending it, receiving the serial data stream across the gap  40 , deconstructing it back into eight (8) individual channels for transmission to D/A converters  30   1  . . .  30   8  is accomplished by the Application Specific Integrated Circuit, (ASIC)  74  shown on both sides of the air gap  40 . The programming of (ASIC)  74  to accomplish the collection and reconstruction of the related data streams is known in the art. The capacitive elements  82 A and  82 B are arranged to receive the output of differential driver  82  and are located on the second plate  32 B 1 , whereas capacitive elements  84 A and  84 B are arranged to provide an input signal to differential receiver  84  and are also located on the second plate  32 B 1 . 
     The capacitor plate coupler  32  comprises a first plate  32 A 1  comprised of elements  76 A,  76 B,  78 A, and  78 B, attached to rotor hub  20  and a second plate  32 B 1  comprised of elements  82 A,  82 B,  84 A, and  84 B, attached to the stationary unit  38 , allows the first plate  32 A 1  to be rotatable relative to the second plate  32 B 1  at a speed of about 1500 rpm and the first plates  32 A 1  and  32 B 1  are arranged, so as to provide capacitive coupling therebetween. The power provided for the capacitive plate coupler  32 , as well as the other elements shown in  FIG. 1  located on the rotor hub  20 , is delivered by the inductive power transfer apparatus  42 , which may be further described with reference to  FIG. 3 . 
       FIG. 3  shows the input stage  42 A separated from the output stage  42 B by the air gap  40  previously discussed with reference to  FIGS. 1 and 2 . The input stage  42 A is comprised of a pulse width modulator  86  and an inductive driver  88  comprised of a differential driver  90  and an inductive element  92  which, in turn, is comprised of three inductive elements  92 A,  928 , and  92 C. The inductive element  92 A receives the output signal from inductive driver  90  and is spaced apart by the air gap  40  from inductive elements  92 B and  92 C which respectively provide power, previously discussed with reference to  FIG. 1 , to high voltage power supply  66 , via signal path  68 , and to low voltage power supply  70 , via signal path  72 . The first inductive element  92 A and the second ( 92 B) and third ( 92 C) transfer energy therebetween by inductive linking. The first, second and third inductive elements  92 A,  92 B and  92 C serve as a pot core pair. 
     The inductive power transfer apparatus  42  has an inductively coupled pot core pair shown in  FIG. 3  as comprising a first pot core  92 A and a second pot core  94 A comprised of inductive elements  92 B and  92 C. 
     In operation, the first pot core  92 A is the driver transmitter (on the stationary base unit  32 ) the second pot core  94 A is the power receiver (on the rotor hub  20 ). The first core  92 A and second core  94 A are arranged so as to be loosely coupled across the air gap  40  of about 0.025 to about 0.030 inches. 
     The signal applied on the driver side, that is at the input stage  42 A at the input to the inductive driver  90 , is a square wave provided by the Pulse Width Modulator (PWM)  86 . In one embodiment, the duty cycle of the PWM  86  is set for 50%, however, if desired, the signal provided by the PWM  86  can be furthered pulse width modulated to reduce the power delivered by the inductive power transfer apparatus  42 . The capability to modify power delivered by the inductive power transfer apparatus  42  allows for other embodiment of the present invention to adapt power to the system operational needs thereof. 
     The PWM  86  drive signal applied to the input of the inductive driver  90  is generated within an Integrated Circuit (IC) of PWM  86 . The IC used is a combination Micro-controller with a PWM block, known in the art, as an element within this IC. The use of a Micro-controller allows the practice of the present invention to be able to program its operation (such as base operating frequency of the PWM), and take advantages of the other features of the IC, such as Analog to Digital converters. The Micro-controller PWM output from the PWM  86  is buffered by traditional power MOSFET gate current drivers. High gain low impedance MOSFETS are implemented so as to preferably form a traditional ½H driver, known in the art, for activation of the drive pot core primary winding shown in  FIG. 3  as first core  92 A. 
     Although the capacitive plate coupler  32  and inductive power transfer apparatus  42  are desired in the practice of the present invention, there are other devices for capacitively coupling data and for inductively transferring power both known in the art. In some prior art devices the data may be inductively coupled either on the same or a second transformer, while in some applications only data is transmitted without power. In the practice of the present invention, the data rate across the gap is high enough, e.g. 50 KHz, to effectively capacitively couple the data directly using differential capacitive coupling. The present invention also contemplates the transfer of data by the use of high frequency carrier modulation, in a manner known in the art. 
     Further, although the hereinbefore discussions described the capacitive plate coupler  32  and the inductive power transfer apparatus  42  as being separate devices, if desired, the capacitive plate coupler  32  and the inductive power transfer apparatus  42  may be arranged in one assembly with the capacitive plate coupler  32  providing capacitive coupling between its first and second plates and the inductive power transfer apparatus  42  providing inductive coupling between its first and second pot cores. 
     The operation of the chip/processor  52  that suppresses the vibrations encountered by the blades of a turbomachine may be further described with reference to  FIG. 4  which is a flow chart  100  illustrating the sequence of operations of the chip/processor  52 . 
     In general, the routines running in the chip/processor  52  provide an active method for damping the vibration frequencies of blades #1 to #8. The damping stabilizes the quantities under analysis by the routines of the present invention by eliminating unwanted or excessive oscillators thereof. The active method selects predetermined values of inductors, resistors and capacitors to provide for frequency damping. These predetermined values are arranged in damping circuits provided by the routines running in the chip/processor  52 . The targeted or controlled frequencies may include those associated with bending, torsion and chordwise modes, all known in the art. The routines running in the chip processor  52  take into account that the vibration blade frequencies vary with the speed of the rotor hub  20 . 
     The present invention provides routines running in the chip/processor  52  that embody a digital code that takes into account transfer functions of LRC (L: inductor, R: resistor, and C: capacitor) shunt circuits used in the damping circuits of the present invention and which are expressed in S-domain which, in turn, allows for real-time adaptive control to accommodate real-time changes in blade frequencies. The S-domain is known in the art and can be programmed in a digital code. 
     The routines provide pre-processing quantities found in look-up tables that include targeted or controlled blade vibration frequencies in the range of the rotor speed of the rotor hub  20  that is to be analyzed and controlled. Depending upon design goals and the specification of the rotor hub  20  under analysis, the blade vibration frequencies may encompass modes such as bending, torsion, and chordwise modes. The look-up tables for the pre-processing quantities further include corresponding inductor and capacitor values (calculated or virtual values, not real physical capacitor or inductor sizes) used for the damping circuits provided by the routines running in the chip/processor  52 , as well as resistor values used in the damping circuits, all related to the blade frequencies to be dampened and analyzed. Further, the pre-processing quantities include gain values and bandwidth values utilized by a controller that controls the activities included in the routines running in the chip/processor  52 . These gain values are selectable for each mode blade vibration frequency under analysis by the routines running in the chip/processor  52  versus the speed of the rotor hub  20 . The routines running in the chip/processor  52  have a start event that, upon completion, passes control to program segment  104 , via signal path  106  as seen in  FIG. 4 . 
     The program segment  104  embodies the initialization routine which sets up input and output channels of the chip/processor  52 . Upon completion, the program segment  104  passes control to program segment  108 , via signal path  110 . 
     The program segment  108  performs real-time Fast Fourier Transform (FFT) analysis upon the quantities received on signal path  112  which is the output of program segment  114 . The program segment  114  receives sensor signals delivered from blades 1-8, to be further described hereinafter, and containing position, strain, and rotation values of the fan blades 1-8. Program segment  114  delivers its received signals to program segment  108 , via signal path  112 . Program segment  108  accesses all of the pre-processing quantities found in the look-up tables previously mentioned. Upon completion, program segment  108  passes control to program segment  116 , via signal path  118 . Further, upon completion, program segment  108  delivers the rotor speed sensor quantity, which represents the rotor speed in rpm (revolution per minutes) of blades 1-8 under analysis, via signal path  120 , to program segment  122 . 
     The program segment  116  also receives the rotor speed sensor quantity and checks to determine if the target mode shift is or is not allowable. This target mode shift, that is the mode being targeted or controlled by the routines being run in the chip/processor  52 , takes into account that the blade frequencies vary with time due to rotor dynamics, non-linear material properties making up blades 1-8, and the aging of blades 1-8 themselves. Thus, it is necessary to determine if the blade vibration frequencies under analysis are different from the blade vibration frequencies stored in the look-up tables for particular rotor speeds and if any differences thereof falls into an allowable or non-allowable tolerance. This determination signifies that the target mode related to the blade vibration frequency under analysis does or does not shift or change due to rotor dynamics and non-linear material properties making up blades 1-8. If the answer to this determination is no, that is, the target mode shift is not allowable, program segment  116  passes control to program segment  128 , via signal path  130 . 
     The program segment  128  measures a new target frequency, which signifies a newly adaptive target frequency replacing the non-allowable target mode measured program segment  108 . The newly adaptive target frequency occurring because of the re-measuring of the blade frequency also provides a new value of inductor and corresponding capacitor value both stored in the look-up tables previously mentioned for the damping circuits embodied in the routines running in the chip/processor  52 . Upon completion, program segment  128  passes control back to program segment  116  by way of signal paths  132  and  118 . 
     As previously mentioned, program segment  116  also determines if the target mode shift is allowable and if this determination yields and answer of yes, program segment  116  passes control to program segment  124 , via signal path  126 . 
     The program segment  124  obtains the virtual inductor size. The virtual inductor size signifies a digitally implemented inductor, not physical inductor. This virtual inductor size is utilized in the damping circuits running in the chip/processor  52  and may be the same as found in program segment  128 . Upon completion, program segment  124  passes control to program segment  134 , via signal path  136 . 
     The program segment  134  selects the predefining virtual resistor value which signifies a digitally implemented resistor, not physical resistor. This virtual resistor value is utilized in the damping circuits running in the chip/processor  52 . At this junction in the routines being run in the chip/processor  52 , values have been selected and, if needed, updated for the transfer functions of LRC shunt circuits of the damping circuit utilized for dampening the vibrations of the fan blade under analysis. Upon completion, program segment  134  passes control to program segment  137 , via signal path  138 . 
     The program segment  137  determines if the controller bandwidth, that is, the bandwidth of the controller embodied in the routines running in the chip/processor  52  that controls the activities of the routines thereof, is good which signifies a good coverage for the peaks of blade frequency vibrations under analysis. The good coverage is indicative that the width of coverage provided by controller, embodied in the routines being run in the chip/processor  52 , is wide enough to cover the peaks of the blade frequency vibrations under analysis. If the width is not wide enough the value of the virtual resistor, previously mentioned in program segment  134 , is increased so as to provide a wider bandwidth, which also means more power is required for the actuation signals applied to blades 1-8, to be further described hereinafter. Conversely, if the width of the controller bandwidth is too wide, a lower valued virtual resistor is selected yielding the need for less power to be required for the actuation signals for blades 1-8. Accordingly, the routines being run in the chip/processor  52  provide optimal virtual resistor values for the damping circuits. If the answer to the determination of the required bandwidth is no, program segment  137  passes control to program segment  140  by way of signal path  142 . 
     The program segment  140  adjusts the virtual resistor value so that the virtual resistor value is correct and the controller bandwidth is correct and passes control back to program segment  137 , by way of signal paths  144  and  138 . 
     As previously discussed, program segment  137  determines if the controller bandwidth is or is not good and if this determination yields and answer of good or yes, program segment  137  passes control to program segment  122 , via signal path  146 . 
     As previously discussed, program segment  122  receives the rotor speed sensor quantity present on signal path  120 . The program segment  122  then uses a controller gain scheduler, which performs the duty of using a family of linear controller gains. The controller gain scheduler is part of the controller embodied in the routines running in the chip/processor  52  that controls the activities of the routines thereof. The routines running in the chip/processor  52  select the controller gains from a look-up table, and the selected gain operates so as to reduce the peak of the vibration frequency of the fan blade under analysis. If not a sufficient amount of the peak of the vibration frequency is being reduced, the value of the controller gain is increased. If the gain of the controller is selected to be too high, then too much power is required for the actuation signals being applied to blades 1-8, which may result in instability related to the actuation signals. The practice of the present invention allows for selecting an optimal controller gain. Upon completion, program segment  122  passes control to program segment  148 , via signal path  150 . 
     Program segment  148  determines if the dampening, being performed by the damping circuits embodied in the routines running in the chip/processor  52 , has exceeded design specifications which is equivalent to the turbomachinery industry&#39;s damping standard known in the art. If the dampening design specifications have not been exceeded, and, thus, more damping provided by the routines running in the chip/processor  52  is desired, program segment  148  passes control to program segment  152 , by way of signal path  154 . 
     Program segment  152  adjusts the controller gain which allows for the routines running in the chip/processor  52  to provide enough damping to meet the design specifications. Upon completion, program segment  152  passes control back to program segment  148 , via signal paths  156  and  150 . 
     As previously discussed, program segment  148  determines if the dampening has or has not exceeded the design specifications, and if the answer to that determination is yes, that is, the required dampening has been met, program segment  148  passes control to program segment  158 , by way of signal path  160 . 
     Program segment  158  generates actuation signals and routes these signals, via signal path  162  to the chip, processor I/O stages  164 , which is part of the chip/processor  52  of  FIG. 1 . The chip, processor I/O stages  164  also routes the sensor signals, previously described with reference to  FIG. 1 , on signal path  166  to program segment  114 , also previously discussed. 
     The determination by program segment  158 , along with the determinations and analysis performed by program segments  108 ,  116 ,  122 ,  124 ,  128 ,  134 ,  137 ,  140 ,  148 , and  152 , is deterministic if actuation signals for fan blades 1-8 are generated, and if so, actuation signals are delivered, via signal path  162  to chip/processor I/O stages  164 . 
     Accordingly, the chip/processor I/O stages  164 , receives sensor signals on signal path  46   1  . . .  46   8 , and routes these sensor signals to the program segment  114 , via signal path  166 . The chip/processor  52 , under control of the program segments illustrated in the flow chart  100  of  FIG. 4 , either generates or does not generate the actuation signals on signal path  162  that alter the response of fan blades 1-8. The chip/processor I/O stages  164  generates activation signals on signal path  50   1  . . .  50   8  that are routed to the capacitive plate coupler  32 , previously discussed with reference to  FIG. 2 . Further, as discussed with reference to  FIG. 2 , the capacitive plate coupler  32  routes the actuation signals, via signal path  24   1  . . .  24   8  to the fan blades  16   1  . . .  16   8 . Further, as previously discussed with reference to  FIGS. 1 and 2 , the sensor signals, originating from fan blades  16   j  . . .  16   8 , are routed on signal paths  22   1  . . .  22   8  to the capacitive plate coupler  32 , which forwards the sensor signals to the chip/processor I/O stages  164  for processing. 
     It should now be appreciated that the chip/processor  52  in response to the program segments shown on flow chart  100  provides a sequence of operations for collecting and analyzing input sensors and, in turn, for providing actuating signals to suppress deleterious vibrations that may otherwise be experienced by fan blades  16   1  . . .  16   8  of a turbomachine. 
     It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the expressed in the appended claims.