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Line 3: | Line 3: | ||
P1. | P1. | ||
(a)i) | (a)i) | ||
− | <math>\begin{bmatrix} | + | <math> |
− | + | \begin{bmatrix} | |
− | + | \dot{x}_1(t) \\ | |
+ | \dot{x}_2(t) | ||
\end{bmatrix}=\begin{bmatrix} | \end{bmatrix}=\begin{bmatrix} | ||
− | -1 &-\frac{1}{2}\\ | + | -1 & -\frac{1}{2} \\ |
\frac{1}{2} & -1 | \frac{1}{2} & -1 | ||
\end{bmatrix}\begin{bmatrix} | \end{bmatrix}\begin{bmatrix} | ||
Line 13: | Line 14: | ||
x_2(t) | x_2(t) | ||
\end{bmatrix}+\begin{bmatrix} | \end{bmatrix}+\begin{bmatrix} | ||
− | \frac{x_0(t)}{2}\\ | + | \frac{x_0(t)}{2} \\ |
\frac{x_3(t)}{2} | \frac{x_3(t)}{2} | ||
\end{bmatrix}=\begin{bmatrix} | \end{bmatrix}=\begin{bmatrix} | ||
− | -1 &-\frac{1}{2}\\ | + | -1 & -\frac{1}{2} \\ |
\frac{1}{2} & -1 | \frac{1}{2} & -1 | ||
\end{bmatrix}\begin{bmatrix} | \end{bmatrix}\begin{bmatrix} | ||
− | x_1(t) \\ | + | x_1(t) \\ |
− | + | x_2(t) | |
− | \end{bmatrix}+begin{bmatrix} | + | \end{bmatrix}+\begin{bmatrix} |
− | \frac{1}{2}&0 \\ | + | \frac{1}{2} & 0 \\ |
− | 0& \frac{1}{2} | + | 0 & \frac{1}{2} |
\end{bmatrix}\begin{bmatrix} | \end{bmatrix}\begin{bmatrix} | ||
− | x_0(t) \\ | + | x_0(t) \\ |
− | + | x_3(t) | |
− | \end{bmatrix}</math> | + | \end{bmatrix} |
+ | </math> | ||
ii) | ii) | ||
Line 72: | Line 74: | ||
iii) | iii) | ||
− | <math>\lambda _1=-\frac{1}{2}</math> | + | <math>\lambda _1=-\frac{1}{2} |
+ | \lambda _2=-\frac{3}{2}\\ | ||
+ | stable \\ | ||
+ | X(t)\rightarrow X(\infty) \\ | ||
+ | as \\ | ||
+ | t\rightarrow \infty</math> | ||
+ | <math>e^{At}=\frac{1}{2}\begin{bmatrix} | ||
+ | e^{-\frac{3}{2}t}+e^{-\frac{1}{2}t} & e^{-\frac{3}{2}t}+e^{-\frac{1}{2}t} \\ | ||
+ | e^{-\frac{3}{2}t}+e^{-\frac{1}{2}t} & e^{-\frac{3}{2}t}+e^{-\frac{1}{2}t} | ||
+ | \end{bmatrix} | ||
+ | t\rightarrow \infty | ||
+ | e^{At}\rightarrow\begin{bmatrix} | ||
+ | 1 & 0 \\ | ||
+ | 0 & 1 | ||
+ | \end{bmatrix} | ||
+ | </math> | ||
+ | <math>X(t)=e^{At}X(0)+\begin{matrix} \int_{0}^{t}e^{A(t-I)}BU dI | ||
+ | \end{matrix} | ||
+ | =e^{At}X(0)+\begin{matrix} \int_{0}^{t}e^{A(t-I)}dI BU | ||
+ | \end{matrix}</math> | ||
+ | <math>X(\infty)=e^(Atrightarrow\infty)X(0)+0Bu=X(0)=\begin{bmatrix} | ||
+ | 4 \\ | ||
+ | 1 | ||
+ | \end{bmatrix}</math> | ||
+ | |||
+ | (b)<math>X(t)=\begin{bmatrix} | ||
+ | 0 & 0 &0 \\ | ||
+ | \frac{1}{2} & -1 & \frac{1}{2}\\ | ||
+ | 0 & \frac{1}{2} & -1 | ||
+ | \end{bmatrix}\begin{bmatrix} | ||
+ | x_0 \\ | ||
+ | x_1 \\ | ||
+ | x_2 | ||
+ | \end{bmatrix}+\begin{bmatrix} | ||
+ | 1 \\ | ||
+ | 0 \\ | ||
+ | 0 | ||
+ | \end{bmatrix}U(t)</math> | ||
+ | |||
+ | |||
+ | ii) | ||
+ | Can’t resolve the rest of questions | ||
+ | |||
+ | |||
+ | P2 | ||
+ | <math>\lambda _1=1 \\ | ||
+ | \lambda _2=-1 \\ | ||
+ | \lambda _3=2 \\ | ||
+ | not stable </math> | ||
+ | |||
+ | <math>C=\begin{bmatrix} | ||
+ | B & AB & A^2B | ||
+ | \end{bmatrix}=\begin{bmatrix} | ||
+ | 1 & 1 & 1 \\ | ||
+ | 1 & 1 & 1 \\ | ||
+ | 2 & 5 & 11 | ||
+ | \end{bmatrix} \\ | ||
+ | rank=2 \\ | ||
+ | not controllable | ||
+ | 0=\begin{bmatrix} | ||
+ | C \\ | ||
+ | CA \\ | ||
+ | CA^2 | ||
+ | \end{bmatrix}=\begin{bmatrix} | ||
+ | 1 & 0 & 0 \\ | ||
+ | 1 & 0 & 0 \\ | ||
+ | 1 & 0 & 0 | ||
+ | \end{bmatrix}\\ | ||
+ | rank=1 \\ | ||
+ | not observable | ||
+ | </math> | ||
+ | |||
+ | For<math>\lambda _1=1 \\ | ||
+ | rank\begin{bmatrix} | ||
+ | \lambda I-A & B | ||
+ | \end{bmatrix}=rank\begin{bmatrix} | ||
+ | 0 & 0 & 0 & 1 \\ | ||
+ | -2 & 2 & 0 & 1 \\ | ||
+ | -5 & 4 & -1 & 2 | ||
+ | \end{bmatrix}=3 \\ | ||
+ | rank\begin{bmatrix} | ||
+ | \lambda I-A \\ | ||
+ | C | ||
+ | \end{bmatrix}=rank\begin{bmatrix} | ||
+ | 0 & 0 & 0 \\ | ||
+ | -2 & 2 & 0 \\ | ||
+ | -5 & 4 & -1 \\ | ||
+ | 1 & 0 & 0 | ||
+ | \end{bmatrix}=3 \\ | ||
+ | </math> | ||
+ | |||
+ | For<math>\lambda _2=-1 \\ | ||
+ | rank\begin{bmatrix} | ||
+ | \lambda I-A & B | ||
+ | \end{bmatrix}=rank\begin{bmatrix} | ||
+ | -2 & 0 & 0 & 1 \\ | ||
+ | -2 & 0 & 0 & 1 \\ | ||
+ | -5 & 4 & -3 & 2 | ||
+ | \end{bmatrix}=2 \\ | ||
+ | uncontrollable \\ | ||
+ | rank\begin{bmatrix} | ||
+ | \lambda I-A \\ | ||
+ | C | ||
+ | \end{bmatrix}=rank\begin{bmatrix} | ||
+ | -2 & 0 & 0 \\ | ||
+ | -2 & 0 & 0 \\ | ||
+ | -5 & 4 & -3 \\ | ||
+ | 1 & 0 & 0 | ||
+ | \end{bmatrix}=2 \\ | ||
+ | unobservable | ||
+ | </math> | ||
+ | |||
+ | For<math>\lambda _3=2 \\ | ||
+ | rank\begin{bmatrix} | ||
+ | \lambda I-A & B | ||
+ | \end{bmatrix}=rank\begin{bmatrix} | ||
+ | 1 & 0 & 0 & 1 \\ | ||
+ | -2 & 3 & 0 & 1 \\ | ||
+ | -5 & 4 & 0 & 2 | ||
+ | \end{bmatrix}=3 \\ | ||
+ | rank\begin{bmatrix} | ||
+ | \lambda I-A \\ | ||
+ | C | ||
+ | \end{bmatrix}=rank\begin{bmatrix} | ||
+ | 1 & 0 & 0 \\ | ||
+ | -2 & 3 & 0 \\ | ||
+ | -5 & 4 & 0 \\ | ||
+ | 1 & 0 & 0 | ||
+ | \end{bmatrix}=3 \\ | ||
+ | The only uncontrollable and unobservable \lambda has negative real part \\ | ||
+ | Stablizable and detectable | ||
+ | </math> | ||
+ | |||
+ | <math>H(S)=C(SI-A)^{-1}B+D=(\frac{1}{S-1}-\frac{2}{(S+1)(S-1)}-\frac{8}{(S-1)(S+1)(S-2)})=\frac{S^2-3S-6}{(S-1)(S+1)(S-2)} \\ | ||
+ | </math> | ||
+ | <math> | ||
+ | P_1=1 \\ | ||
+ | P_2=-1 \\ | ||
+ | P_3=2 \\ | ||
+ | not all poles have neqative real parts \\ | ||
+ | not BIBO stable | ||
+ | </math> | ||
+ | |||
+ | P3 | ||
+ | <math>X(t)=\begin{bmatrix} | ||
+ | X_1(t) \\ | ||
+ | X_2(t) | ||
+ | \end{bmatrix} | ||
+ | \dot{x}_1(t)=-tx_1(t) | ||
+ | \dot{x}_2(t)=-costx_1(t)-tx_2(t) | ||
+ | </math> | ||
+ | <math>\Phi(t)=\begin{bmatrix} | ||
+ | \Phi_1(t) & \Phi_2(t) | ||
+ | \end{bmatrix} | ||
+ | for \Phi_1(t) \\ | ||
+ | assume \\ | ||
+ | X(0)=\begin{bmatrix} | ||
+ | 1 \\ | ||
+ | 0 | ||
+ | \end{bmatrix} \\ | ||
+ | X_1(0)=1 X_2(0)=0 | ||
+ | </math> | ||
+ | <math>X_1(t)=e^{-\int_{0}^{t}IdI}\\ | ||
+ | X_1(0)=e^{-\frac{1}{2}t^2} | ||
+ | \dot{x}_2(t)=-coste^{-\frac{1}{2}t^2}-tx_2(t) | ||
+ | for \Phi_2(t) \\ | ||
+ | assume \\ | ||
+ | X(0)=\begin{bmatrix} | ||
+ | 0 \\ | ||
+ | 1 | ||
+ | \end{bmatrix} \\ | ||
+ | X_1(t)=0 | ||
+ | \dot{x}_2(t)=-tx_2(t) | ||
+ | x_2(t)=e^{-\frac{1}{2}t^2}x_2(0)=e^{-\frac{1}{2}t^2} | ||
+ | \Phi_2(t)=\begin{bmatrix} | ||
+ | 0 \\ | ||
+ | e^{-\frac{1}{2}t^2} | ||
+ | \end{bmatrix} \\ | ||
+ | </math> | ||
+ | |||
+ | |||
+ | <math>\Phi(t)=e^{-\int_{0}^{t}AdI}=e^{{-\int_{0}^{t}}\begin{bmatrix} | ||
+ | -t & 0 \\ | ||
+ | -cost & -t | ||
+ | \end{bmatrix}}dI=e^{\begin{bmatrix} | ||
+ | -\frac{1}{2}t^2 & 0 \\ | ||
+ | sint & -\frac{1}{2}t^2 | ||
+ | \end{bmatrix}}=e^{\begin{bmatrix} | ||
+ | -\frac{1}{2}t^2 & 0 \\ | ||
+ | 0 &-\frac{1}{2}t^2 | ||
+ | \end{bmatrix}}e^{\begin{bmatrix} | ||
+ | 0 & 0 \\ | ||
+ | sint & 0 | ||
+ | \end{bmatrix}}=\begin{bmatrix} | ||
+ | e^{-\frac{1}{2}t^2} & 0 \\ | ||
+ | 0 & e^{-\frac{1}{2}t^2} | ||
+ | \end{bmatrix}\begin{bmatrix} | ||
+ | 1 & 0 \\ | ||
+ | sint & 1 | ||
+ | \end{bmatrix}=\begin{bmatrix} | ||
+ | e^{-\frac{1}{2}t^2} & 0 \\ | ||
+ | sinte^{-\frac{1}{2}t^2} & e^{-\frac{1}{2}t^2} | ||
+ | \end{bmatrix} | ||
+ | </math> | ||
+ | <math>\Phi(tI)=\Phi(t)\Phi^{-1}(I)=\begin{bmatrix} | ||
+ | e^{-\frac{1}{2}t^2} & 0 \\ | ||
+ | sinte^{-\frac{1}{2}t^2} & e^{-\frac{1}{2}t^2} | ||
+ | \end{bmatrix}\begin{bmatrix} | ||
+ | e^{-\frac{1}{2}I^2} & 0 \\ | ||
+ | sinIe^{-\frac{1}{2}I^2} & e^{-\frac{1}{2}I^2} | ||
+ | \end{bmatrix}=\begin{bmatrix} | ||
+ | e^{-\frac{1}{2}(t^2-I^2)} & 0 \\ | ||
+ | (sint-sinI)e^{-\frac{1}{2}(t^2-I^2)} & e^{-\frac{1}{2}(t^2-I^2)} | ||
+ | \end{bmatrix} | ||
+ | </math> |
Latest revision as of 04:15, 21 May 2017
AC-2 2014
P1. (a)i) $ \begin{bmatrix} \dot{x}_1(t) \\ \dot{x}_2(t) \end{bmatrix}=\begin{bmatrix} -1 & -\frac{1}{2} \\ \frac{1}{2} & -1 \end{bmatrix}\begin{bmatrix} x_1(t) \\ x_2(t) \end{bmatrix}+\begin{bmatrix} \frac{x_0(t)}{2} \\ \frac{x_3(t)}{2} \end{bmatrix}=\begin{bmatrix} -1 & -\frac{1}{2} \\ \frac{1}{2} & -1 \end{bmatrix}\begin{bmatrix} x_1(t) \\ x_2(t) \end{bmatrix}+\begin{bmatrix} \frac{1}{2} & 0 \\ 0 & \frac{1}{2} \end{bmatrix}\begin{bmatrix} x_0(t) \\ x_3(t) \end{bmatrix} $
ii) $ A=\begin{bmatrix} -1 & \frac{1}{2} \\ \frac{1}{2} & -1 \end{bmatrix}=\begin{bmatrix} -1 & 0 \\ 0 & -1 \end{bmatrix}+\begin{bmatrix} 0 & \frac{1}{2} \\ \frac{1}{2} & 0 \end{bmatrix}=\begin{bmatrix} -1 & 0 \\ 0 & -1 \end{bmatrix}+\begin{bmatrix} 1 & 1 \\ -1 & 1 \end{bmatrix}\begin{bmatrix} -\frac{1}{2} & 0 \\ 0 & \frac{1}{2} \end{bmatrix}\begin{bmatrix} \frac{1}{2} & -\frac{1}{2} \\ \frac{1}{2} & \frac{1}{2} \end{bmatrix} $
$ e^A=\begin{bmatrix} e^{-1} & 0 \\ 0 & e^{-1} \end{bmatrix}\begin{bmatrix} 1 & 1 \\ -1 & 1 \end{bmatrix}\begin{bmatrix} e^{-\frac{1}{2}} & 0 \\ 0 & e^\frac{1}{2} \end{bmatrix}\begin{bmatrix} \frac{1}{2} & -\frac{1}{2} \\ \frac{1}{2} & \frac{1}{2} \end{bmatrix}=\frac{1}{2}\begin{bmatrix} e^{-\frac{3}{2}}+e^{-\frac{1}{2}} & -e^{-\frac{3}{2}}+e^{-\frac{1}{2}} \\ -e^{-\frac{3}{2}}+e^{-\frac{1}{2}} & e^{-\frac{3}{2}}+e^{-\frac{1}{2}} \end{bmatrix} $
iii) $ \lambda _1=-\frac{1}{2} \lambda _2=-\frac{3}{2}\\ stable \\ X(t)\rightarrow X(\infty) \\ as \\ t\rightarrow \infty $ $ e^{At}=\frac{1}{2}\begin{bmatrix} e^{-\frac{3}{2}t}+e^{-\frac{1}{2}t} & e^{-\frac{3}{2}t}+e^{-\frac{1}{2}t} \\ e^{-\frac{3}{2}t}+e^{-\frac{1}{2}t} & e^{-\frac{3}{2}t}+e^{-\frac{1}{2}t} \end{bmatrix} t\rightarrow \infty e^{At}\rightarrow\begin{bmatrix} 1 & 0 \\ 0 & 1 \end{bmatrix} $ $ X(t)=e^{At}X(0)+\begin{matrix} \int_{0}^{t}e^{A(t-I)}BU dI \end{matrix} =e^{At}X(0)+\begin{matrix} \int_{0}^{t}e^{A(t-I)}dI BU \end{matrix} $ $ X(\infty)=e^(Atrightarrow\infty)X(0)+0Bu=X(0)=\begin{bmatrix} 4 \\ 1 \end{bmatrix} $
(b)$ X(t)=\begin{bmatrix} 0 & 0 &0 \\ \frac{1}{2} & -1 & \frac{1}{2}\\ 0 & \frac{1}{2} & -1 \end{bmatrix}\begin{bmatrix} x_0 \\ x_1 \\ x_2 \end{bmatrix}+\begin{bmatrix} 1 \\ 0 \\ 0 \end{bmatrix}U(t) $
ii)
Can’t resolve the rest of questions
P2
$ \lambda _1=1 \\ \lambda _2=-1 \\ \lambda _3=2 \\ not stable $
$ C=\begin{bmatrix} B & AB & A^2B \end{bmatrix}=\begin{bmatrix} 1 & 1 & 1 \\ 1 & 1 & 1 \\ 2 & 5 & 11 \end{bmatrix} \\ rank=2 \\ not controllable 0=\begin{bmatrix} C \\ CA \\ CA^2 \end{bmatrix}=\begin{bmatrix} 1 & 0 & 0 \\ 1 & 0 & 0 \\ 1 & 0 & 0 \end{bmatrix}\\ rank=1 \\ not observable $
For$ \lambda _1=1 \\ rank\begin{bmatrix} \lambda I-A & B \end{bmatrix}=rank\begin{bmatrix} 0 & 0 & 0 & 1 \\ -2 & 2 & 0 & 1 \\ -5 & 4 & -1 & 2 \end{bmatrix}=3 \\ rank\begin{bmatrix} \lambda I-A \\ C \end{bmatrix}=rank\begin{bmatrix} 0 & 0 & 0 \\ -2 & 2 & 0 \\ -5 & 4 & -1 \\ 1 & 0 & 0 \end{bmatrix}=3 \\ $
For$ \lambda _2=-1 \\ rank\begin{bmatrix} \lambda I-A & B \end{bmatrix}=rank\begin{bmatrix} -2 & 0 & 0 & 1 \\ -2 & 0 & 0 & 1 \\ -5 & 4 & -3 & 2 \end{bmatrix}=2 \\ uncontrollable \\ rank\begin{bmatrix} \lambda I-A \\ C \end{bmatrix}=rank\begin{bmatrix} -2 & 0 & 0 \\ -2 & 0 & 0 \\ -5 & 4 & -3 \\ 1 & 0 & 0 \end{bmatrix}=2 \\ unobservable $
For$ \lambda _3=2 \\ rank\begin{bmatrix} \lambda I-A & B \end{bmatrix}=rank\begin{bmatrix} 1 & 0 & 0 & 1 \\ -2 & 3 & 0 & 1 \\ -5 & 4 & 0 & 2 \end{bmatrix}=3 \\ rank\begin{bmatrix} \lambda I-A \\ C \end{bmatrix}=rank\begin{bmatrix} 1 & 0 & 0 \\ -2 & 3 & 0 \\ -5 & 4 & 0 \\ 1 & 0 & 0 \end{bmatrix}=3 \\ The only uncontrollable and unobservable \lambda has negative real part \\ Stablizable and detectable $
$ H(S)=C(SI-A)^{-1}B+D=(\frac{1}{S-1}-\frac{2}{(S+1)(S-1)}-\frac{8}{(S-1)(S+1)(S-2)})=\frac{S^2-3S-6}{(S-1)(S+1)(S-2)} \\ $ $ P_1=1 \\ P_2=-1 \\ P_3=2 \\ not all poles have neqative real parts \\ not BIBO stable $
P3 $ X(t)=\begin{bmatrix} X_1(t) \\ X_2(t) \end{bmatrix} \dot{x}_1(t)=-tx_1(t) \dot{x}_2(t)=-costx_1(t)-tx_2(t) $ $ \Phi(t)=\begin{bmatrix} \Phi_1(t) & \Phi_2(t) \end{bmatrix} for \Phi_1(t) \\ assume \\ X(0)=\begin{bmatrix} 1 \\ 0 \end{bmatrix} \\ X_1(0)=1 X_2(0)=0 $ $ X_1(t)=e^{-\int_{0}^{t}IdI}\\ X_1(0)=e^{-\frac{1}{2}t^2} \dot{x}_2(t)=-coste^{-\frac{1}{2}t^2}-tx_2(t) for \Phi_2(t) \\ assume \\ X(0)=\begin{bmatrix} 0 \\ 1 \end{bmatrix} \\ X_1(t)=0 \dot{x}_2(t)=-tx_2(t) x_2(t)=e^{-\frac{1}{2}t^2}x_2(0)=e^{-\frac{1}{2}t^2} \Phi_2(t)=\begin{bmatrix} 0 \\ e^{-\frac{1}{2}t^2} \end{bmatrix} \\ $
$ \Phi(t)=e^{-\int_{0}^{t}AdI}=e^{{-\int_{0}^{t}}\begin{bmatrix} -t & 0 \\ -cost & -t \end{bmatrix}}dI=e^{\begin{bmatrix} -\frac{1}{2}t^2 & 0 \\ sint & -\frac{1}{2}t^2 \end{bmatrix}}=e^{\begin{bmatrix} -\frac{1}{2}t^2 & 0 \\ 0 &-\frac{1}{2}t^2 \end{bmatrix}}e^{\begin{bmatrix} 0 & 0 \\ sint & 0 \end{bmatrix}}=\begin{bmatrix} e^{-\frac{1}{2}t^2} & 0 \\ 0 & e^{-\frac{1}{2}t^2} \end{bmatrix}\begin{bmatrix} 1 & 0 \\ sint & 1 \end{bmatrix}=\begin{bmatrix} e^{-\frac{1}{2}t^2} & 0 \\ sinte^{-\frac{1}{2}t^2} & e^{-\frac{1}{2}t^2} \end{bmatrix} $
$ \Phi(tI)=\Phi(t)\Phi^{-1}(I)=\begin{bmatrix} e^{-\frac{1}{2}t^2} & 0 \\ sinte^{-\frac{1}{2}t^2} & e^{-\frac{1}{2}t^2} \end{bmatrix}\begin{bmatrix} e^{-\frac{1}{2}I^2} & 0 \\ sinIe^{-\frac{1}{2}I^2} & e^{-\frac{1}{2}I^2} \end{bmatrix}=\begin{bmatrix} e^{-\frac{1}{2}(t^2-I^2)} & 0 \\ (sint-sinI)e^{-\frac{1}{2}(t^2-I^2)} & e^{-\frac{1}{2}(t^2-I^2)} \end{bmatrix} $