Adaptive controller

1. An adaptive controller for a cyclic signal, the adaptive controller for actively reducing influences of the cyclic signal, which the cyclic signal exerts to an objective evaluation point by way of a predetermined transfer path, by adding an adaptive signal, which synchronizes with the cyclic signal, to the cyclic signal, which a vibration generation source generates,

the predetermined transfer path comprising a first transfer path, and a second transfer path which differs from the first transfer path;

the adaptive controller comprising:

an adaptive-signal generator for generating the adaptive signal, whose constituent element comprises a first amplitude filter coefficient and a first phase filter coefficient, in the first transfer path based on an angular frequency of a specific frequency, the specific frequency being at least one frequency component selected from a plurality of frequency components making the cyclic signal;

a first residual-error detector for detecting a first residual error, which results from adding the adaptive signal to the cyclic signal by way of a predetermined first transfer characteristic, at a first observation point, which is located between the adaptive-signal generator and the objective evaluation point in the first transfer path, the first residual error being added to a cyclic signal transferred by way of the second transfer path;

an observation-point target-value setter for setting an amplitude target value based on the angular frequency and a transfer characteristic of the second transfer path, the amplitude target value being comprised in a cyclic residual-error target value, the amplitude target value complying with the angular frequency, the cyclic residual-error target value being a target value of the first residual error at the first observation point; and

a first filter-coefficient updater for updating the first amplitude filter coefficient and the first phase filter coefficient based on the angular frequency, the first residual error and the cyclic residual-error target value.

2. The adaptive controller according to claim 1 , wherein the cyclic residual-error target value comprises a phase target value, which complies with the angular frequency.

3. The adaptive controller according to claim 1 , further comprising:

a first estimated-transfer-function calculator for calculating a first transfer-function estimated value for a transfer function of the predetermined first transfer characteristic based on the angular frequency, wherein:

the adaptive-signal generator generates the adaptive signal in the first transfer path, the adaptive signal being produced according to following Equation (1); and

the first filter-coefficient updater updates the first amplitude filter coefficient and the first phase filter coefficient in Equation (1) according to following Equations (2), (3) and (4) or following Equations (5), (6) and (7) based on the angular frequency, the first residual error, the first transfer-function estimated value and the cyclic residual-error target value,

y 1 n =a 1 n ·sin(ω· t n +φ1 n )  Equation (1):

wherein:

y 1 n : Adaptive Signal;

a 1 n : First Amplitude Filter Coefficient;

φ 1 n : First Phase Filter Coefficient;

ω: Angular Frequency of Specific Frequency (i.e., One of Frequency Components of Cyclic Signal);

t n : Time (i.e., Sampling Cycle T×Discrete Time n); and

n: Discrete Time;

a 1 n+1 =a 1 n −μ a1 ·Ah 1·( e 1 n −etarget n )·sin(ω· t n +φ1 n +Φh 1)  Equation (2):

φ1 n+1 =φ1 n −μ φ1 ·( e 1 n −etarget n )·cos(ω· t n +φ1 n +Φh 1)  Equation (3):

etarget n =a e ·sin(ω· t n )  Equation (4):

wherein:

μ a1 : Step-size Parameter for First Amplitude;

μ φ1 : Step-size Parameter for First Phase;

Ah 1 : Amplitude Component of Estimated Value Gh 1 for Transfer Function of First Transfer Characteristic Gh;

Φh 1 : Phase Component of Estimated Value Gh 1 for Transfer Function of First Transfer Characteristic Gh;

e 1 n : Residual-error Signal;

etarget n : Residual-error Target Value; and

a e : Amplitude Target Value;

a 1 n+1 =a 1 n −μ a1 ·Ah 1·( e 1 n −etarget n )·sin(ω· t n +φ1 n +Φh 1)  Equation (5):

φ1 n+1 =φ1 n −μ φ1 ·Ah 1 ·a 1 n ·( e 1 n −etarget n )·cos(ω· t n +φ1 n +Φh 1)  Equation (6):

etarget n =a e ·sin(ω· t n ).  Equation (7):

4. The adaptive controller according to claim 2 , further comprising:

a first estimated-transfer-function calculator for calculating a first transfer-function estimated value for a transfer function of the predetermined first transfer characteristic based on the angular frequency, wherein:

the adaptive-signal generator generates the adaptive signal in the first transfer path, the adaptive signal being produced according to following Equation (8); and

the first filter-coefficient updater updates the first amplitude filter coefficient and the first phase filter coefficient in Equation (8) according to following Equations (9), (10) and (11) or following Equations (12), (13) and (14) based on the angular frequency, the first residual error, the first transfer-function estimated value and the cyclic residual-error target value,

y 1 n =a 1 n ·sin(ω· t n +φ1 n )  Equation (8):

wherein:

y 1 : Adaptive Signal;

a 1 : First Amplitude Filter Coefficient;

φ 1 : First Phase Filter Coefficient;

ω: Angular Frequency of Specific Frequency (i.e., One of Frequency Components of Cyclic Signal);

t n : Time (i.e., Sampling Cycle T×Discrete Time n); and

n: Discrete Time;

a 1 n+1 =a 1 n −μ a1 ·Ah 1·( e 1 n −etarget n )·sin(ω· t n +φ1 n +Φh 1)  Equation (9):

φ1 n+1 =φ1 n −μ φ1 ·( e 1 n −etarget n )·cos(ω· t n +φ1 n +Φh 1)  Equation (10):

etarget n =a e ·sin(ω· t n +φ e )  Equation (11):

wherein:

μ a1 : Step-size Parameter for First Amplitude;

μ φ1 : Step-size Parameter for First Phase;

Ah 1 : Amplitude Component of Estimated Value Gh 1 for Transfer Function of First Transfer Characteristic Gh;

Φh 1 : Phase Component of Estimated Value Gh 1 for Transfer Function of First Transfer Characteristic;

e 1 n : Residual-error Signal;

etarget n : Residual-error Target Value;

a e : Amplitude Target Value; and

φ e : Phase Target Value;

a 1 n+1 =a 1 n −μ a1 ·Ah 1·( e 1 n −etarget n )·sin(ω· t n +φ1 n +Φh 1)  Equation (12):

φ1 n+1 =φ1 n −μ φ1 ·Ah 1 ·a 1 n ·( e 1 n −etarget n )·cos(ω· t n +φ1 n +Φh 1)  Equation (13):

etarget n =a e ·sin(ω· t n +φ e ).  Equation (14):

5. The adaptive controller according to claim 1 , wherein the observation-point target-value setter stores the amplitude target value, which complies with the angular frequency, in advance, and sets the amplitude target value based on the angular frequency of the cyclic signal, which the vibration generation source generates actually.

6. The adaptive controller according to claim 1 , wherein the observation-point target-value setter comprises:

an imaginary adaptive-signal generator for generating an imaginary adaptive signal in the second transfer path imaginarily, the imaginary adaptive signal being produced according to following Equation (15), whose constituent elements comprise a second amplitude filter coefficient and a second phase filter coefficient, based on the angular frequency;

a vibration detector for detecting a second-observation-point vibration, which occurs based on the cyclic signal, at a second observation point in the second transfer path;

an imaginary residual-error detector for detecting an imaginary residual error, which occurs by adding the imaginary adaptive signal to the cyclic signal imaginarily by way of a predetermined imaginary transfer characteristic at the second observation point based on the imaginary adaptive signal and the second-observation-point vibration;

an imaginary transfer-function estimator for calculating an imaginary transfer-function estimated value for a transfer function of the predetermined imaginary transfer characteristic based on the angular frequency;

a second filter-coefficient updater for updating the second amplitude filter coefficient and the second phase filter coefficient in Equation (15) according to following Equations (16) and (17) or following Equations (18) and (19) based on the angular frequency, the imaginary residual error and the imaginary transfer-function estimated value; and

an updated target-value setter for setting the updated second amplitude filter coefficient at the amplitude target value according to following Equation (20),

y 2 n =a 2 n ·sin(ω· t n +φ2 n )  Equation (15):

wherein:

y 2 n : Imaginary Adaptive Signal;

a 2 n : Second Amplitude Filter Coefficient

φ 2 n : Second Phase Filter Coefficient

ω: Angular Frequency of Specific Frequency (i.e., One of Frequency Components of Cyclic Signal); and

t n : Time (i.e., Sampling Cycle T×Discrete Time n);

a 2 n+1 =a 2 n −μ a2 ·Ah 2· e 2 n ·sin(ω· t n +φ2 n +Φh 2)  Equation (16):

φ2 n+1 =φ2 n −μ φ2 ·e 2 n ·cos(ω· t n +φ2 n +Φh 2)  Equation (17):

wherein:

μ a2 : Step-size Parameter for Second Amplitude;

μ φ2 : Step-size Parameter for Second Phase;

Ah 2 : Amplitude Component of Estimated Value Gh 2 for Transfer Function of Imaginary Transfer Characteristic G 2 ;

Φh 2 : Phase Component of Estimated Value Gh 2 for Transfer Function of Imaginary Transfer Characteristic G 2 ; and

e 2 n : Imaginary Residual-error Signal;

a 2 n+1 =a 2 n −μ a2 ·Ah 2 ·e 2 n ·sin(ω· t n +φ2 n +Φh 2)  Equation (18):

φ2 n+1 =φ2 n −μ φ2 ·Ah 2· a 2 n ·e 2 n ·cos(ω· t n +φ2 n +Φh 2)  Equation (19):

a e =a 2 n+1 .  Equation (20):

7. The adaptive controller according to claim 2 , wherein:

the observation-point target value setter sets the phase target value based on a transfer characteristic of the second transfer path.

8. The adaptive controller according to claim 7 , wherein the observation-point target-value setter stores the phase target value, which complies with the angular frequency, in advance, and sets the phase target value based on the angular frequency of the cyclic signal, which the vibration generation source generates actually.

9. The adaptive controller according to claim 7 , wherein the observation-point target-value setter comprises:

an imaginary adaptive-signal generator for generating an imaginary adaptive signal in the second transfer path imaginarily, the imaginary adaptive signal being produced according to following Equation (21), whose constituent elements comprise a second amplitude filter coefficient and a second phase filter coefficient, based on the angular frequency;

a vibration detector for detecting a second-observation-point vibration, which occurs based on the cyclic signal, at a second observation point in the second transfer path;

an imaginary residual-error detector for detecting an imaginary residual error, which occurs by adding the imaginary adaptive signal to the cyclic signal imaginarily by way of a predetermined imaginary transfer characteristic at the second observation point based on the imaginary adaptive signal and the second-observation-point vibration;

an imaginary transfer-function estimator for calculating an imaginary transfer-function estimated value for a transfer function of the predetermined imaginary transfer characteristic based on the angular frequency;

a second filter-coefficient updater for updating the second amplitude filter coefficient and the second phase filter coefficient in Equation (21) according to following Equations (22) and (23) or following Equations (24) and (25) based on the angular frequency, the imaginary residual error and the imaginary transfer-function estimated value; and

an updated target-value setter for setting the updated second phase filter coefficient at the phase target value according to following Equation (26),

y 2 n =a 2 n ·sin(ω· t n +φ2 n )  Equation (21):

wherein:

y 2 n : Imaginary Adaptive Signal;

a 2 n : Second Amplitude Filter Coefficient

φ 2 n : Second Phase Filter Coefficient

ω: Angular Frequency of Specific Frequency (i.e., One of Frequency Components of Cyclic Signal); and

t n : Time (i.e., Sampling Cycle T×Discrete Time n);

a 2 n+1 =a 2 n −μ a2 ·Ah 2 ·e 2 n ·sin(ω· t n +φ2 n +Φh 2)  Equation (22):

φ2 n+1 =φ2 n −μ φ2 ·e 2 n ·cos(ω· t n +φ2 n +Φh 2)  Equation (23):

wherein:

μ a2 : Step-size Parameter for Second Amplitude;

μ φ2 : Step-size Parameter for Second Phase;

Ah 2 : Amplitude Component of Estimated Value Gh 2 for Transfer Function of Imaginary Transfer Characteristic G2;

Φh 2 : Phase Component of Estimated Value Gh 2 for Transfer Function of Imaginary Transfer Characteristic G 2 ; and

e 2 n : Imaginary Residual-error Signal;

a 2 n+1 =a 2 n −μ a2 ·Ah 2 ·e 2 n ·sin(ω· t n +φ2 n +Φh 2)  Equation (24):

φ2 n+1 =φ2 n −μ φ2 ·Ah 2· a 2 n ·e 2 n ·cos(ω· t n +φ2 n +Φh 2)  Equation (25):

φ e =φ2 n+1 .  Equation (26):