“…When the Lagrange multipliers are set to zero, that is, ε * = 0 and/or ε * = 0, the control τ * can be calculated (including the solution at the boundaries) by solving (45). Otherwise, when the Lagrange multipliers are non-zero, that is, ε * = 0 and/or ε * = 0, the control τ * has to be equal to the boundary values, τ max or τ min , based on the KKT conditions.…”