ABSTRACT
Control system specifications can be divided into two categories, performance specifications and robustness specifications. Although the boundaries between the two can be fuzzy, the performance specifications describe the desired response of the nominal system to command inputs. The robustness specifications limit the degradation in performance due to variations in the system and disturbances. This chapter describes the classical performance specifications for single-input single-output (SISO) linear time-invariant (LTI) systems. It discusses the classical robustness specifications for SISO LTI systems. The chapter provides some miscellaneous classical specifications. It then describes performance specifications that are unique to multi-input multi-output (MIMO) systems. This is followed by a section on robustness specifications for MIMO systems. Static error constants describe the ability of a system to reduce or eliminate steady-state errors. Step response envelope specifications are often used as the time-domain specifications for control system design.
