System identification device, system identification method, system identification program, and recording medium recording system identification program
AssigneesNational University Corporation, Iwate University, Rion Co., Ltd.
InventorsKiyoshi Nishiyama, Masahiro Sunohara, Nobuhiko Hiruma, Chiho Haruta, Makoto Tateno
Life of this patent
Estimating the term…
Abstract
A system identification device for performing fast real-time identification for a system from input/output data includes a filter robust to disturbance, by setting the maximum energy gain from the disturbance to a filter error, as an evaluation criterion, smaller than a given upper limit. The filter estimates a state estimation value of a state of the system.
Claims18
A system identification method for performing fast real-time identification for a system from input/output data, the method comprising:
- estimating a state estimation value x{circumflex over ( )}k|k of a state xk of the system from a received signal uk of an interface in an acoustic system or a communication system and from an observation signal yk of an echo or a feedback by using a filter robust to disturbance in such a manner that a maximum energy gain from the disturbance to a filter error is, as an evaluation criterion, set smaller than a given upper limit γf2;
- and
- canceling out the echo or the feedback using a result of the state estimation value x{circumflex over ( )}k|k, wherein
- the filter is, by Expressions (49) to (62) below, provided to a state space model represented by Expressions (11) to (13) below to estimate the state estimation value x{circumflex over ( )}k|k of the state xk of the system:
- x
- k
- +
- 1
- =
-
- x
- k
- +
- G
- k
-
- w
- k
- ,
- w
- k
- ,
- x
- k
- ∈
- ℛ
- N
-
- (
- 11
- )
- y
- k
- =
-
- H
- k
-
- x
- k
- +
- υ
- k
- ,
- y
- k
- ,
- υ
- k
- ∈
- ℛ
-
- (
- 12
- )
- z
- k
- =
-
- H
- k
-
- x
- k
- ,
- z
- k
- ∈
- ℛ
- ,
- H
- k
- ∈
- ℛ
- 1
- ×
- N
-
- (
- 13
- )
- x
- ^
- k
- ❘
- k
- =
-
- x
- ^
- k
- -
- 1
- ❘
- k
- -
- 1
- +
- K
- s
- ,
- k
-
- (
- y
- k
- -
- H
- k
-
- x
- ^
- k
- -
- 1
- ❘
- k
- -
- 1
- )
-
- (
- 49
- )
- K
- s
- ,
- k
- =
-
- K
- ~
- k
-
- (
- :
- ,
- 1
- )
- R
- e
- ,
- k
-
- (
- 1
- ,
- 1
- )
-
- (
- 50
- )
- b
- k
- =
-
- b
- k
- -
- 1
- -
- ρ
- -
- 1
-
- K
- ~
- k
-
- W
-
-
- e
- _
- k
-
- (
- 51
- )
- S
- _
- k
- =
-
- ρ
-
- S
- _
- k
- -
- 1
- +
- e
- _
- k
- T
-
- W
-
-
- e
- ~
- _
- k
-
- (
- 52
- )
- e
- _
- k
- =
-
- χ
- k
- -
- 1
-
- e
- ~
- _
- k
-
- (
- 53
- )
- χ
- k
- =
-
- ρ
- -
- 1
-
- R
- e
- ,
- k
-
- W
-
- (
- 54
- )
- R
- e
- ,
- k
- =
-
- R
- e
- ,
- k
- -
- 1
- +
- e
- ~
- k
-
- e
- ~
- k
- T
- S
- k
- -
- 1
- -
- e
- ~
- _
- k
-
- μ
- ~
- k
-
- (
- 55
- )
- e
- ~
- _
- k
- =
-
- S
- _
- k
- -
- 1
-
- μ
- ~
- k
- T
-
- (
- 56
- )
- K
- ~
- k
- =
-
- m
- ~
- k
- -
- b
- k
- -
- 1
-
- μ
- ~
- k
-
- (
- 57
- )
- [
- m
- ~
- k
- μ
- ~
- k
- ]
- =
-
- [
- 0
- K
- ~
- k
- -
- 1
- ]
- +
- [
- 1
- a
- k
- -
- 1
- ]
-
- e
- ~
- k
- T
- S
- k
- -
- 1
-
- (
- 58
- )
- a
- k
- =
-
- a
- k
- -
- 1
- -
- ρ
- -
- 1
-
- K
- ~
- k
- -
- 1
-
- W
-
-
- e
- k
-
- (
- 59
- )
- S
- k
- =
-
- ρ
-
-
- S
- k
- -
- 1
- +
- e
- k
- T
-
- W
-
-
- e
- ~
- k
-
- (
- 60
- )
- e
- k
- =
-
- χ
- k
- -
- 1
- -
- 1
-
- e
- ~
- k
-
- (
- 61
- )
- e
- ~
- k
- =
-
- c
- k
- +
- C
- k
- -
- 1
-
- a
- k
- -
- 1
-
- (
- 62
- )
- where Ck and W are defined by the following expressions:
- C
- k
- =
- [
- H
- k
- H
- k
- ]
- ,
- W
- =
- [
- 1
- 0
- 0
- -
- γ
- f
- -
- 2
- ]
- ,
- ck∈R2×1 is a first column vector of C
- C
- ⋓
- k
- =
- [
- u
- k
- …
- u
- k
- -
- N
- u
- k
- …
- u
- k
- -
- N
- ]
- (
- 63
- )
- C
- ⋓
- k
-
- (
- :
- ,
- 1
- )
- =
- c
- k
- =
- [
- u
- k
- u
- k
- ]
- T
- ,
- C
- ⋓
- k
-
- (
- :
- ,
- i
- )
- =
- C
- ⋓
- k
- -
- 1
-
- (
- :
- ,
- i
- -
- 1
- )
- ,
-
- i
- =
- 2
- ,
- …
-
- ,
- N
- +
- 1
-
-
- H
- k
- =
- [
- u
- k
- ,
- …
-
- ,
- u
- k
- -
- N
- +
- 1
- ]
- T
- ,
- (
- 64
- )
- xk:
- a state vector or merely a state;
- unknown, and this is a target for estimation,
- x0:
- an initial state;
- unknown,
- wk:
- system noise;
- unknown,
- vk:
- observation noise;
- unknown,
- yk:
- an observation signal;
- taken as filter input, and known,
- zk:
- an output signal;
- unknown,
- Gk:
- a drive matrix;
- known upon execution,
- Hk:
- an observation matrix, known,
- x{circumflex over ( )}k|k:
- an estimation value, using observation signals y0 to yk, of the state xk (an impulse response of an unknown system) at time k;
- provided by a filter equation,
- x{circumflex over ( )}k+1|k:
- a single-step prediction value, using the observation signals y0 to yk, of a state xk+1 at the time k;
- provided by the filter equation,
- x{circumflex over ( )}−1|−1:
- an initial estimation value of the state;
- unknown in a normal situation, but zero is used for convenience,
- Ks,k:
- a filter gain;
- obtained from a matrix Σ{circumflex over ( )}k|k−1,
- Re,k:
- an auxiliary variable;
- a 2×2 matrix,
- χk:
- a conversion factor;
- a 2×2 matrix,
- N:
- a dimension (a tap number) of the state vector;
- provided in advance,
- μ{tilde over ( )}k:
- an N+1-th 1×2 row vector of KUk;
- obtained by KUk,
- mk:
- an N×2 matrix including first to N-th rows of KUk;
- obtained by KUk,
- W:
- a weighting matrix;
- determined by γf,
- ak:
- a forward linear prediction factor;
- an N-dimensional column vector,
- bk:
- a backward linear prediction factor;
- an N-dimensional column vector,
- ek:
- an ex-post forward prediction error;
- a two-dimensional column vector,
- ek:
- an ex-post backward prediction error;
- a two-dimensional column vector, and
- γf:
- an attenuation level;
- provided upon designing.
A system identification method for performing fast real-time identification for a system from input/output data, the method comprising:
- estimating a state estimation value x{circumflex over ( )}k|k of a state xk of the system from a received signal uk of an interface in an acoustic system or a communication system and from an observation signal yk of an echo or a feedback by using a filter robust to disturbance in such a manner that a maximum energy gain from the disturbance to a filter error is, as an evaluation criterion, set smaller than a given upper limit γf2;
- and
- canceling out the echo or the feedback using a result of the state estimation value x{circumflex over ( )}k|k, wherein
- the filter is, by Expressions (49), (50), (55), (58), (60) to (62) below, provided to a state space model represented by Expressions (11) to (13) below to estimate the state estimation value x{circumflex over ( )}k|k of the state xk of the system:
- x
- k
- +
- 1
- =
-
- x
- k
- +
- G
- k
-
- w
- k
- ,
- w
- k
- ,
- x
- k
- ∈
- ℛ
- N
-
- (
- 11
- )
- y
- k
- =
-
- H
- k
-
- x
- k
- +
- υ
- k
- ,
- y
- k
- ,
- υ
- k
- ∈
- ℛ
-
- (
- 12
- )
- z
- k
- =
-
- H
- k
-
- x
- k
- ,
- z
- k
- ∈
- ℛ
- ,
- H
- k
- ∈
- ℛ
- 1
- ×
- N
-
- (
- 13
- )
- x
- ^
- k
- ❘
- k
- =
-
- x
- ^
- k
- -
- 1
- ❘
- k
- -
- 1
- +
- μ
-
- K
- ~
- k
-
- (
- :
- ,
- 1
- )
- R
- e
- ,
- k
-
- (
- 1
- ,
- 1
- )
-
- (
- y
- k
- -
- H
- k
-
- x
- ^
- k
- -
- 1
- ❘
- k
- -
- 1
- )
-
- (
- 49
- )
- ,
- (
- 50
- )
- R
- e
- ,
- k
- =
-
- R
- e
- ,
- k
- -
- 1
- +
- c
- k
-
- c
- k
- T
- S
- k
- -
- 1
- -
- c
- k
- -
- N
-
- μ
- ~
- k
-
- (
- 55
- )
- [
- K
- ~
- k
- μ
- ~
- k
- ]
- =
-
- [
- c
- k
- /
- S
- k
- -
- 1
- K
- ~
- k
- -
- 1
- ]
-
- (
- 58
- )
- S
- k
- =
-
- ρ
-
-
- S
- k
- -
- 1
- +
- c
- k
- T
-
- W
-
-
- c
- ~
- k
- =
- ρ
-
-
- S
- k
- -
- 1
- +
- (
- 1
- -
- γ
- f
- -
- 2
- )
-
- u
- k
- 2
-
- (
- 60
- )
- e
- ~
- k
- =
-
- c
- k
- ,
- e
- k
- =
- c
- k
- ,
- c
- k
- =
- [
- u
- k
- u
- k
- ]
- T
-
- (
- 61
- )
- ,
- (
- 62
- )
- where Ck and W are defined by the following expressions:
- C
- k
- =
- [
- H
- k
- H
- k
- ]
- ,
- W
- =
- [
- 1
- 0
- 0
- -
- γ
- f
- -
- 2
- ]
- ,
- ck∈R2×1 is a first column vector of Ck=[ck, . . . , ck−N+1],
- C
- ˘
- k
- =
- [
- u
- k
- …
- u
- k
- -
- N
- u
- k
- …
- u
- k
- -
- N
- ]
- (
- 63
- )
- C
- ˘
- k
-
- (
- :
- ,
- 1
- )
- =
- c
- k
- =
- [
- u
- k
- u
- k
- ]
- T
- ,
- C
- ˘
- k
-
- (
- :
- ,
- i
- )
- =
- C
- ˘
- k
- -
- 1
-
- (
- :
- ,
- i
- -
- 1
- )
- ,
-
- i
- =
- 2
- ,
- …
-
- ,
- N
- +
- 1
- H
- k
- =
- [
- u
- k
- ,
- …
-
- ,
- u
- k
- -
- N
- +
- 1
- ]
- T
- ,
- (
- 64
- )
- xk:
- a state vector or merely a state;
- unknown, and this is a target for estimation,
- x0:
- an initial state;
- unknown,
- wk:
- system noise;
- unknown,
- vk:
- observation noise;
- unknown,
- yk:
- an observation signal;
- taken as filter input, and known,
- zk:
- an output signal;
- unknown,
- Gk:
- a drive matrix;
- known upon execution,
- Hk:
- an observation matrix, known,
- x{circumflex over ( )}k|k:
- an estimation value, using observation signals y0 to yk, of the state xk (an impulse response of an unknown system) at time k;
- provided by a filter equation,
- x{circumflex over ( )}k+1|k:
- a single-step prediction value, using the observation signals y0 to yk, of a state xk+1 at the time k;
- provided by the filter equation,
- x{circumflex over ( )}−1|−1:
- an initial estimation value of the state;
- unknown in a normal situation, but zero is used for convenience,
- Ks,k:
- a filter gain;
- obtained from a matrix Σ{circumflex over ( )}k|k−1,
- Re,k:
- an auxiliary variable;
- a 2×2 matrix,
- N:
- a dimension (a tap number) of the state vector;
- provided in advance,
- μ{tilde over ( )}k:
- an N+1-th 1×2 row vector of KUk;
- obtained by KUk,
- W:
- a weighting matrix;
- determined by γf,
- ek:
- an ex-post forward prediction error;
- a two-dimensional column vector,
- ek:
- an ex-post backward prediction error;
- a two-dimensional column vector,
- γf:
- an attenuation level;
- provided upon designing, and
- μ:
- a step size (a relaxation factor);
- a real number of μ>0, and provided in advance.
A system identification method for performing fast real-time identification for a system from input/output data, the method comprising:
- estimating a state estimation value x{circumflex over ( )}k|k of a state xk of the system from a received signal uk of an interface in an acoustic system or a communication system and from an observation signal yk of an echo or a feedback by using a filter robust to disturbance in such a manner that a maximum energy gain from the disturbance to a filter error is, as an evaluation criterion, set smaller than a given upper limit γf2;
- and
- canceling out the echo or the feedback using a result of the state estimation value x{circumflex over ( )}k|k, wherein
- the filter is, by Expressions (49), (50), (55), (58) below, provided to a state space model represented by Expressions (11) to (13) below to estimate the state estimation value x{circumflex over ( )}k|k of the state xk of the system:
- x
- k
- +
- 1
- =
- x
- k
- +
- G
- k
-
- w
- k
- ,
- w
- k
- ,
- x
- k
- ∈
- N
- (
- 11
- )
- y
- k
- =
- H
- k
-
- x
- k
- +
- v
- k
- ,
- y
- k
- ,
- v
- k
- ∈
- (
- 12
- )
- z
- k
- =
- H
- k
-
- x
- k
- ,
- z
- k
- ∈
- ,
- H
- k
- ∈
- 1
- ×
- N
- (
- 13
- )
- x
- ^
- k
- |
- k
- =
- x
- ^
- k
- -
- 1
- |
- k
- -
- 1
- +
- μ
-
- K
- ~
- k
-
- (
- :
- ,
- 1
- )
- R
- e
- ,
- k
-
- (
- 1
- ,
- 1
- )
-
- (
- y
- k
- -
- H
- k
-
- x
- ^
- k
- -
- 1
- |
- k
- -
- 1
- )
- (
- 49
- )
- ,
- (
- 50
- )
- R
- e
- ,
- k
- =
- R
- e
- ,
- k
- -
- 1
- +
- ϵ
- 0
-
- c
- k
-
- c
- k
- T
- -
- c
- k
- -
- N
-
- μ
- ~
- k
- (
- 55
- )
- [
- K
- ~
- k
- μ
- ~
- k
- ]
- =
- [
- ϵ
- 0
-
- c
- k
- K
- ~
- k
- -
- 1
- ]
- (
- 58
- )
- where Ck and W are defined by the following expressions:
- C
- k
- =
- [
- H
- k
- H
- k
- ]
- ,
- W
- =
- [
- 1
- 0
- 0
- -
- γ
- f
- -
- 2
- ]
- ,
- ck∈R2×1 is a first column vector of Ck=[ck, . . . , ck−N+1],
- C
- ˘
- k
- =
- [
- u
- k
- …
- u
- k
- -
- N
- u
- k
- …
- u
- k
- -
- N
- ]
- (
- 63
- )
- C
- ˘
- k
-
- (
- :
- ,
- 1
- )
- =
- c
- k
- =
- [
- u
- k
- u
- k
- ]
- T
- ,
- C
- ˘
- k
-
- (
- :
- ,
- i
- )
- =
- C
- ˘
- k
- -
- 1
-
- (
- :
- ,
- i
- -
- 1
- )
- ,
-
- i
- =
- 2
- ,
- …
-
- ,
- N
- +
- 1
- H
- k
- =
- [
- u
- k
- ,
- …
-
- ,
- u
- k
- -
- N
- +
- 1
- ]
- T
- ,
- (
- 64
- )
- xk:
- a state vector or merely a state;
- unknown, and this is a target for estimation,
- x0:
- an initial state;
- unknown,
- wk:
- system noise;
- unknown,
- vk:
- observation noise;
- unknown,
- yk:
- an observation signal;
- taken as filter input, and known,
- zk:
- an output signal;
- unknown,
- Gk:
- a drive matrix;
- known upon execution,
- Hk:
- an observation matrix, known,
- x{circumflex over ( )}k|k:
- an estimation value, using observation signals y0 to yk, of the state xk (an impulse response of an unknown system) at time k;
- provided by a filter equation,
- x{circumflex over ( )}k+1|k:
- a single-step prediction value, using the observation signals y0 to yk, of a state xk+1 at the time k;
- provided by the filter equation,
- x{circumflex over ( )}−1|−1:
- an initial estimation value of the state;
- unknown in a normal situation, but zero is used for convenience,
- Ks,k:
- a filter gain;
- obtained from a matrix Σ{circumflex over ( )}k|k−1,
- Re,k:
- an auxiliary variable;
- a 2×2 matrix,
- N:
- a dimension (a tap number) of the state vector;
- provided in advance,
- μ{tilde over ( )}k:
- an N+1-th 1×2 row vector of KUk;
- obtained by KUk,
- W:
- a weighting matrix;
- determined by γf,
- ek:
- an ex-post forward prediction error;
- a two-dimensional column vector,
- ek:
- an ex-post backward prediction error;
- a two-dimensional column vector,
- ε0:
- an optional positive constant;
- ε0>0, and provided in advance,
- γf:
- an attenuation level;
- provided upon designing, and
- μ:
- a step size (a relaxation factor);
- a real number of μ>0, and provided in advance.
Dependencies are inferred from the claim text.