- The design of the closed-loop control system must take into account the system performance to load-disturbance and set-point changes and its robustness to variation of the controlled process characteristics, preserving the well-known trade-off among all these variables. This paper face with this combined servo/regulation performance and robustness problem. The proposed method is formulated as an optimization problem for combined performance (not for independent operation modes), including also the robustness property as a constraint. The accomplishment of the claimed robustness is checked and then, the PID controller gives a good performance with also a precise and specific robustness degree. The proposed robust based PID control design is tested against other tuning methods.