How and what is the time period of following function

Question

Andrew Kutsiak 2021-12-2

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1601705-how-and-what-is-the-time-period-of-following-function

编辑： Jon 2021-12-2

Hi, I am a little bit struggling to find a time period for the folowing code and it's graph.

It is a step response of a RCL circuit and I need to find a time period of it.

R = 1;%Given values

C = 0.01;

L = 0.01;

RC = R*C;

LC = L*C;

sys = tf([1/LC],[1 R/L 1/LC])%upper part and denominator part

subplot(2,1,1)

step(sys)

grid;

subplot(2,1,2)

impulse(sys)

grid;

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Jon 2021-12-2

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1601705-how-and-what-is-the-time-period-of-following-function#answer_846240

编辑：Jon 2021-12-2

在 MATLAB Online 中打开

I think you are looking for a characteristic time duration for your circuit. One common criteria is the settling time following a step command. Here is some code that would calculate that

R = 1;%Given values
C = 0.01;
L = 0.01;
RC = R*C;
LC = L*C;
sys = tf([1/LC],[1 R/L 1/LC])%upper part and denominator part 
% get response data
[yStep,tStep] = step(sys)
% find settling time to step input
% which we define here as the last time it leaves band of  +/-3% of final value
settlingThreshold = 0.03; % could use other value here, depends on you criteria
finalValue = 1; 
idx = find(abs(yStep - finalValue)/finalValue > settlingThreshold,1,'last');
tSettle = tStep(idx)

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 2

Star Strider 2021-12-2

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1601705-how-and-what-is-the-time-period-of-following-function#answer_846275

在 MATLAB Online 中打开

The stepinfo function will give essentially all the relevant information —

R = 1;%Given values

C = 0.01;

L = 0.01;

RC = R*C;

LC = L*C;

sys = tf([1/LC],[1 R/L 1/LC])%upper part and denominator part

sys = 10000 ------------------- s^2 + 100 s + 10000 Continuous-time transfer function.

SI = stepinfo(sys)

SI = struct with fields:

RiseTime: 0.0164 TransientTime: 0.0808 SettlingTime: 0.0808 SettlingMin: 0.9315 SettlingMax: 1.1629 Overshoot: 16.2929 Undershoot: 0 Peak: 1.1629 PeakTime: 0.0359

figure

step(sys)

grid

.

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Jon 2021-12-2

编辑：Jon 2021-12-2

Thanks, I didn't know about the stepinfo function, very nice!

I see now that I can find that command immediately by Googling the terms: matlab step response settling, also it is on the list searching with these same terms on the internal documentation.

I'll have to remember to search more before writing code!

请先登录，再进行评论。