Doctoral Dissertations


"Delays are found in many industrial pneumatic and hydraulic systems, and as a result, the performance of the overall closed-loop system deteriorates unless they are explicitly accounted. It is also possible that the dynamics of such systems are uncertain. On the other hand, optimal control of time-delay systems in the presence of known and uncertain dynamics by using state and output feedback is of paramount importance. Therefore, in this research, a suite of novel optimal adaptive control (OAC) techniques are undertaken for linear and nonlinear continuous time-delay systems in the presence of uncertain system dynamics using state and/or output feedback.

First, the optimal regulation of linear continuous-time systems with state and input delays by utilizing a quadratic cost function over infinite horizon is addressed using state and output feedback. Next, the optimal adaptive regulation is extended to uncertain linear continuous-time systems under a mild assumption that the bounds on system matrices are known. Subsequently, the event-triggered optimal adaptive regulation of partially unknown linear continuous time systems with state-delay is addressed by using integral reinforcement learning (IRL). It is demonstrated that the optimal control policy renders asymptotic stability of the closed-loop system provided the linear time-delayed system is controllable and observable. The proposed event-triggered approach relaxed the need for continuous availability of state vector and proven to be zeno-free.

Finally, the OAC using IRL neural network based control of uncertain nonlinear time-delay systems with input and state delays is investigated. An identifier is proposed for nonlinear time-delay systems to approximate the system dynamics and relax the need for the control coefficient matrix in generating the control policy. Lyapunov analysis is utilized to design the optimal adaptive controller, derive parameter/weight tuning law and verify stability of the closed-loop system”--Abstract, page iv.


Sarangapani, Jagannathan, 1965-

Committee Member(s)

Erickson, Kelvin T.
Krishnamurthy, K.
Zawodniok, Maciej Jan, 1975-
Nadendla, V. Sriram Siddhardh


Electrical and Computer Engineering

Degree Name

Ph. D. in Electrical Engineering


Missouri University of Science and Technology

Publication Date

Fall 2020

Journal article titles appearing in thesis/dissertation

  • A Linear Quadratic Regulator for Linear Time-invariant Systems with Input and State Delay
  • Optimal Adaptive Output Feedback Control of Uncertain Linear Continuous-time Systems with State and Input Delays
  • Event-triggered Optimal Adaptive Control of Partially Unknown Linear Continuous-time Systems with State Delay
  • Optimal Adaptive Control of Uncertain Nonlinear Continuous-Time Systems with Input and State Delays


xi, 147 pages

Note about bibliography

Includes bibliographic references.


© 2020 Rohollah Moghadam, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Thesis Number

T 11984