TFC robust control design for time delay systems — Analysis and example

This paper is focused on the use of the ring of quasipolynomial meromorphic functions (R_MS) for algebraic control of time delay systems (TDS) in a robust sense. Unlike many other contributions, we intend to utilize Two-Feedback-Controllers (TFC) control system structure instead of a simple negative control feedback loop, which involves making some analysis first. Tunable controller parameters are set such that requirements of robust stability and robust performance are satisfied. The theoretically described procedure is verified by simulations in Matlab/Simulink environment for temperature control of a laboratory circuit heating plant containing internal (state) delays. The appliance provides unordinary step responses, which makes it difficult to be modeled, identified and controlled in general. The obtained results show the applicability of the controller design methodology.