Torque prediction using model predictive control
A method includes obtaining multiple parameters associated with operation of a turbine engine. The method also includes applying a model predictive control algorithm to the parameters to predict a future torque value of a shaft of the turbine engine, the future torque value indicating a likelihood of future shaft shear. The method further includes, in response to the future torque value being outside of an expected range, performing an action to reduce risk of the future shaft shear.
1 . A method comprising: obtaining multiple parameters associated with operation of a turbine engine; applying a model predictive control algorithm to the parameters to predict a future torque value of a shaft of the turbine engine, the future torque value indicating a likelihood of future shaft shear, wherein applying the model predictive control algorithm to the parameters comprises processing multiple state equations associated with a torque of the shaft of the turbine engine using the parameters comprising a shaft speed, a fuel flow quantity, an air-fuel ratio, a mechanical torque of the shaft, functions of time that vary for the turbine engine, a time-varying engine characteristic coefficient, an engine characteristic constant, a pressure of a fuel manifold, a temperature of the fuel manifold, and a gas constant; wherein the state equations comprise:
W
fqty
.
=
N
E
(
t
)
Q
(
t
)
f
3
(
λ
(
t
)
)
N
˙
E
=
γ
(
t
)
f
4
(
W
fqty
(
t
)
)
d
λ
(
t
)
dt
dQ
(
t
)
dt
λ
˙
=
d
dt
(
α
(
N
E
)
P
manifold
(
t
)
Q
(
t
)
×
R
×
T
manifold
(
t
)
)
where W ƒqty is the fuel flow quantity, N E is the shaft speed, λ is the air-fuel ratio, Q is the mechanical torque of the shaft, ƒ 3 and ƒ 4 are the functions of time that vary for the turbine engine, γ(t) is the time-varying engine characteristic coefficient, α is the engine characteristic constant, P manifold and T manifold are the pressure and the temperature of the fuel manifold, and R is the gas constant; and in response to the future torque value being outside of an expected range, controlling the turbine engine based on the predicted future torque to perform an action to reduce risk of the future shaft shear.
2 . The method of claim 1 , wherein performing the action comprises at least one of:
stopping the turbine engine;
slowing a speed of the turbine engine; and
transmitting a notification for review by a human operator.
3 . The method of claim 1 , further comprising:
determining whether the future torque value is outside of the expected range.
4 . The method of claim 1 , wherein the model predictive control algorithm is an explicit model predictive control (eMPC) algorithm.
5 . The method of claim 1 , wherein the turbine engine is part of an aviation vehicle.
6 . A system comprising: at least one processing device configured to: obtain multiple parameters associated with operation of a turbine engine; apply a model predictive control algorithm to the parameters to predict a future torque value of a shaft of the turbine engine, the future torque value indicating a likelihood of future shaft shear, wherein, to apply the model predictive control algorithm to the parameters, the at least one processing device is configured to process multiple state equations associated with a torque of the shaft of the turbine engine using the parameters comprising a shaft speed, a fuel flow quantity, an air-fuel ratio, a mechanical torque of the shaft, functions of time that vary for the turbine engine, a time-varying engine characteristic coefficient, an engine characteristic constant, a pressure of a fuel manifold, a temperature of the fuel manifold, and a gas constant; wherein the state equations comprise:
W
fqty
.
=
N
E
(
t
)
Q
(
t
)
f
3
(
λ
(
t
)
)
N
˙
E
=
γ
(
t
)
f
4
(
W
fqty
(
t
)
)
d
λ
(
t
)
dt
dQ
(
t
)
dt
λ
˙
=
d
dt
(
α
(
N
E
)
P
manifold
(
t
)
Q
(
t
)
×
R
×
T
manifold
(
t
)
)
where W ƒqty is the fuel flow quantity, N E is the shaft speed, λ is the air-fuel ratio, Q is the mechanical torque of the shaft, ƒ 3 and ƒ 4 are the functions of time that vary for the turbine engine, γ(t) is the time-varying engine characteristic coefficient, α is the engine characteristic constant, P manifold and T manifold are the pressure and the temperature of the fuel manifold, and R is the gas constant; and in response to the future torque value being outside of an expected range, control the turbine engine based on the predicted future torque to perform an action to reduce risk of the future shaft shear.
7 . The system of claim 6 , wherein to perform the action, the at least one processing device is configured to perform at least one of:
stop the turbine engine;
slow a speed of the turbine engine; and
transmit a notification for review by a human operator.
8 . The system of claim 6 , wherein the at least one processing device is further configured to determine whether the future torque value is outside of the expected range.
9 . The system of claim 6 , wherein the model predictive control algorithm is an explicit model predictive control (eMPC) algorithm.
10 . The system of claim 6 , wherein the turbine engine is part of an aviation vehicle.
11 . A non-transitory machine-readable medium containing instructions that when executed cause at least one processor of an electronic device to: obtain multiple parameters associated with operation of a turbine engine; apply a model predictive control algorithm to the parameters to predict a future torque value of a shaft of the turbine engine, the future torque value indicating a likelihood of future shaft shear, wherein the instructions that when executed cause the at least one processor to apply the model predictive control algorithm to the parameters comprise instructions that when executed cause the at least one processor to process multiple state equations associated with a torque of the shaft of the turbine engine using the parameters comprising a shaft speed, a fuel flow quantity, an air-fuel ratio, a mechanical torque of the shaft, functions of time that vary for the turbine engine, a time-varying engine characteristic coefficient, an engine characteristic constant, a pressure of a fuel manifold, a temperature of the fuel manifold, and a gas constant; wherein the state equations comprise:
W
fqty
*
=
N
E
(
t
)
Q
(
t
)
f
a
(
λ
(
t
)
)
N
E
*
=
γ
(
t
)
f
4
(
W
fqty
(
t
)
)
d
λ
(
t
)
dt
dQ
(
t
)
dt
λ
*
=
d
dt
(
α
(
N
E
)
P
manifold
(
t
)
Q
(
t
)
×
R
×
T
manifold
(
t
)
)
where W ƒqty is the fuel flow quantity, N E is the shaft speed, λ is the air-fuel ratio, Q is the mechanical torque of the shaft, ƒ 3 and ƒ 4 are the functions of time that vary for the turbine engine, γ(t) is the time-varying engine characteristic coefficient, α is the engine characteristic constant, P manifold and T manifold are the pressure and the temperature of the fuel manifold, and R is the gas constant; and in response to the future torque value being outside of an expected range, control the turbine engine based on the predicted future torque to perform an action to reduce risk of the future shaft shear.
12 . The non-transitory machine-readable medium of claim 11 , wherein the instructions that when executed cause the at least one processor to perform the action comprise:
instructions that when executed cause the at least one processor to perform at least one of:
stop the turbine engine;
slow a speed of the turbine engine; and
transmit a notification for review by a human operator.
13 . The non-transitory machine-readable medium of claim 11 , further containing instructions that when executed cause the at least one processor to determine whether the future torque value is outside of the expected range.
14 . The non-transitory machine-readable medium of claim 11 , wherein the model predictive control algorithm is an explicit model predictive control (eMPC) algorithm.