immense difference between continous and discrete model in simulink using function c2d

7 次查看（过去 30 天）

Zhang Leiqi 2014-4-1

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/123956-immense-difference-between-continous-and-discrete-model-in-simulink-using-function-c2d

C2DTEST.mdl

Hello,everyone, I'm now working to discritize a continuous model in simulink. I use the function c2d. Following is the code and the step response is perfectly matched

      TF = tf([36.58 41.67 1], [1625 121.7 1])
      TF_d = c2d(TF, 1e-3, 'zoh')
      step(TF,10,'r')
      hold on
      step(TF_d,10,'b')

However,when I simulate the dicretized model in simulink (using step command), the model doesn't converge. Following is the simulation results The red line is result of the continuous model and the yellow line is the result of the discretize model. I feel really puzzeld and hope to obtain your help. The simulink model in the attachment. Thank you very much!