can someone please help me coding this saturation equations in matlab

hello

u_s = sat(u) = [sat(u_1),.....,sat(u_m)]^T

sat(u_i) = sign(u_i)*min{|u_i|,u_max,i} ,u_max,i >0

U_i = [-u_max,i , u_max,i]

u_s = sat(u) = (1+psi_sat(u))*u

psi_sat(u) = diag (psi_1(u_1),....,psi_m(u_m))

where psi_i(u_i) ∈ R is a non-linear function

psi_i(u_i) = 0 for u_i ∈ U_i

or

psi_i(u_i) = (sat(u_i) /|u_i|)-1 for u_i ∉ U_i

can some tell me how to code this saturation equations . thank you

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Answer 1

[Torsten]

m, umax and u have to be defined previously.

psi = zeros(m,1);
idx = abs(u) > umax;
psi(idx) = sign(u(idx)).*min(abs(u(idx)),umax(idx));
psi_sat = diag(psi);
us = (1 + psi_sat)*u