integral sliding mode surface equation in simulink

i built a comparation result for my 3 degree of freedom robot arm controller in simulink for both sliding mode and integral sliding mode controller, i write the sliding mode and works fine but i coudn't write the integral sliding mode controller, any help please?

where E are error from the desired displacemnt and actual displaement (teta1-teta2) and are gains. the question is how can i write derivative of s in simulink, really appreciate your help

[Aliff Ashraff]

same for me but iama working on coupled tank system. Do you know how to write coding for the integral part?

[chengqi]

Hi, can you share me with the matlab code about the integral sliding mode controller showed by you?

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