Nonlinear model predictive control slack variable negative

Hello,

I'm using the Nonlinear MPC on Simulink.

Why I get the error:

• All entries of input All entries of input Slack0 must be nonnegative. must be nonnegative.

I have tried to change the weight on the slack variable ε (in the cost function), but this doesn't always work.

Thank you

[Mert Buyukkopru]

Hi,

I have same problem in Nonlinear MPC, Could you please share how to define the slack variable in Constraint function ?