title: Identification of FOPDT and SOPDT process dynamics using closed loop test.
abstract: In this paper, identification of stable and unstable first order, second order overdamped and underdamped process dynamics with time delay is presented. Relay with hysteresis is used to induce a limit cycle output and using this information, unknown process model parameters are estimated. State space based generalized analytical expressions are derived to achieve accurate results. To show the performance of the proposed method expressions are also derived for systems with a zero. In real time systems, measurement noise is an important issue during identification of process dynamics. A relay with hysteresis reduces the effect of measurement noise, in addition a new multiloop control strategy is proposed to recover the original limit cycle. Simulation results are included to validate the effectiveness of the proposed method.
authors.affiliation: Department of Electronics and Electrical Engineering, Indian Institute of Technology Guwahati, 781039, India. Electronic address: bajarangbali@iitg.ac.in.
authors.forename: Raghunath
authors.initials: R
authors.lastname: Bajarangbali
authors.affiliation: Department of Electronics and Electrical Engineering, Indian Institute of Technology Guwahati, 781039, India. Electronic address: smajhi@iitg.ac.in.
authors.forename: Somanath
authors.initials: S
authors.lastname: Majhi
authors.affiliation: Department of Electronics and Electrical Engineering, Indian Institute of Technology Guwahati, 781039, India. Electronic address: p.saurabh@iitg.ac.in.
authors.forename: Saurabh
authors.initials: S
authors.lastname: Pandey
keywords: Identification; Measurement noise; Multiloop structure; Relay with hysteresis; Time delay