using sat(.) function i.e y=sat (x) function

Hi all,

can someone put me through this I need to use a sat function in a sliding mode control problem : below is the alternate code I saw Y=(atan(5.*s*1/e)-atan(-5.*s*1/e))/(pi); where s is the sliding manifold,e=1 but I intend to use: And is the same with sat function even though I got result

function Y=sat(s);
% % sat is the saturation function with unit limits and unit slope.
% if s>1
% Y=1;
% elseif s<-1 
% Y=-1;
% else 
% Y=s;
% end

[Yousef Sardahi]

The saturation function can be coded as follows :

function y=sat(x,delta)
kk=1/delta;
% sat is the saturation function with unit limits and unit slope.
if abs(x)>delta
% elseif x<-delta 
y=sign(x);
else 
y=kk*x;
end

[Walter Roberson]

That code is not vectorized. A vectorized approach is

sat = @(x, delta) min(max(x/delta, -1), 1);

Answer 1

[Walter Roberson]

Your existing code would have a problem if you were to input a vector or matrix of values. I suggest instead,

sat = @(s) min(max(X, -1), 1);