IEVref: 351-47-41 ID: Language: en Status: Standard Term: optimal control Synonym1: Synonym2: Synonym3: Symbol: Definition: type of control for which the performance index reaches a largest or smallest value under specified conditionsNote 1 to entry: Performance index is a mathematical expression which characterises the quality of control under given conditions.Note 2 to entry: The determination of optimal control parameters frequently results from minimising integral criteria which are often called control areas from the geometric interpretation of the integral. The most important ones are:${I}_{\text{IAE}}=\underset{0}{\overset{\infty }{\int }}|e\left(t\right)|\cdot \text{d}t$ Criterion of Integral Absolute Error${I}_{\text{ISE}}=\underset{0}{\overset{\infty }{\int }}{e}^{2}\left(t\right)\cdot \text{d}t$ Criterion of Integral Squared Error${I}_{\text{ITAE}}=\underset{0}{\overset{\infty }{\int }}t\cdot |e\left(t\right)|\cdot \text{d}t$ Criterion of Integral of Time multiplied Absolute value of ErrorTherein e(t) is the control difference variable as a function of time as answer to an input appropriate to the technological task, for example a response to a stepwise change of the reference variable.Note 3 to entry: This entry was numbered 351-26-35 in IEC 60050-351:2006. Publication date: 2013-11 Source: Replaces: Internal notes: CO remarks: TC/SC remarks: VT remarks: Domain1: Domain2: Domain3: Domain4: Domain5: