自动控制原理知识点很多,但出题相对固定;控制理论的诸多不完整、不严谨的使用与方法姑且用着,以后有需要再作考量;801控制原理的考察范围不完全明晰,视为风险的一部分; 总结必要的概念、结论、方法、经验、典例等,仅为知识体系,不覆盖做题分析能力(灵活使用,掌握足够的技巧方法,面对题目"非无之无")考试面前,适当理解以对抗风险,但应用为先!

默认章节#

考情分析#

考察点主要在控制理论,电路,电机,模电等知识点涉及不深

欧拉公式#

$$ e^{i\theta}=\cos\theta+i\sin\theta\\ \sin\theta=\frac{e^{i\theta}-e^{-i\theta}}{2i}\\ \cos\theta=\frac{e^{i\theta}+e^{-i\theta}}{2} $$

常见函数拉氏变换#

$$ \delta(t),\delta(t-\tau_0), 1(t), t, \frac{t^n}{n!}, e^{\pm at}, \sin\omega t, \cos\omega t $$ $$ \begin{array}{} f(t)& F(s)\\ \delta(t) & 1 \\ \delta(t-\tau_0) & e^{-\tau_0s} \\ \ \\ 1(t) & \frac{1}{s} \\ \ \\ t & \frac{1}{s^2} \\ \ \\ \frac{t^n}{n!} &\frac{1}{s^{n+1}}\\ \ \\ e^{\pm at} & \frac{1}{s\mp a}\\ \ \\ \sin{\omega t} & \frac{\omega}{s^2+\omega^2}\\ \ \\ \cos{\omega t} & \frac{s}{s^2+\omega^2} \end{array} $$

留数法(单根,重根)#

$$ 单根:\frac{c_i}{s-p_i}\\ c_i=\lim\limits_{s\to p_i}[(s-p_i)F(s)] $$

$$ 重根:\frac{c_m}{(s-p_1)^m},\frac{c_{m-1}}{(s-p_1)^{m-1}},\cdots\\ c_m=\lim\limits_{s\to p_1}[(s-p_1)^m F(s)] \\ c_{m-1}=\frac{1}{1!}\cdot\lim\limits_{s\to p_1}\frac{\mathrm{d}}{\mathrm{d}s}[(s-p_1)^{m} F(s)] \\ c_{m-2}=\frac{1}{2!} \cdot\lim\limits_{s\to p_1}\frac{\mathrm{d^2}}{\mathrm{d}s^2}[(s-p_1)^{m} F(s)] \\ \cdots $$

拉氏变换基本定理#

线性性质、微分定理、积分定理、实位移定理、复位移定理、初值定理、终值定理

$$ \mathscr{L}[af_1(t) \pm bf_2(t)]=aF_1(s) \pm bF_2(s) $$

$$ \left\{ \begin{array}{l} \mathscr{L}[f^{(n)}(t)]=s^nF(s)(零初始条件)\qquad \mathscr{L}[f^{\prime}(t)]=sF(s)-f(0) \\ \mathscr{L}[f^{(n)}(t)]=s^nF(s)-s^{n-1}f(0)-s^{n-2}f^{\prime}(0)-\cdots -sf^{(n-2)}(0)-f^{(n-1)}(0) \end{array} \right. $$

$$ \left\{ \begin{array}{l} \mathscr{L}[{\underbrace{\int \cdots \int}_n} f(t)(dt)^n]=\frac{1}{s^n}F(s)(零初始条件)\qquad {\color{grey}\mathscr{L}[\int f(t)dt]=\frac{1}{s}F(s)+\frac{1}{s}f^{(-1)}(0)}\\ {\color{grey}\mathscr{L}[{\underbrace{\int \cdots \int}_n} f(t)(dt)^n]=\frac{1}{s^n}F(s)+\frac{1}{s^n}f^{(-1)}(0)+\frac{1}{s^{n-1}}f^{(-2)}(0)+\cdots +\frac{1}{s}f^{(-n)}(0)} \end{array} \right.\qquad $$

$$ \mathscr{L}[f(t \pm \tau_0)]=e^{\pm \tau_0s}F(s)\qquad注: \mathscr{L}[f'(t\pm \tau_0)]\xlongequal[g(t)=f(t\pm \tau_0)]{g(t)=f'(t)}e^{\pm \tau_0s}sF(s)\\ \mathscr{L}[e^{\mp At}f(t)]=F(s\pm A)\qquad 注:\mathscr{L}[e^{\mp At}f'(t)]\xlongequal{g(t)=f'(t)}G(s\pm A)=(s\pm A)F(s\pm A) $$

$$ \lim\limits_{t\to0}f(t)=\lim\limits_{s\to \infty}s\cdot F(s)\\ \lim\limits_{t\to \infty}f(t)=\lim\limits_{s\to 0}s\cdot F(s) $$