Purdue University Graduate School
Lendek_thesis.pdf (3.41 MB)


Download (3.41 MB)
posted on 2021-05-05, 15:59 authored by Attila LendekAttila Lendek
In this thesis work, a novel approach for the design of a fractional order proportional integral
derivative (FOPID) controller is proposed. This design introduces a new time-varying FOPID controller
to mitigate a voltage spike at the controller output whenever a sudden change to the setpoint occurs. The
voltage spike exists at the output of the proportional integral derivative (PID) and FOPID controllers when a
derivative control element is involved. Such a voltage spike may cause a serious damage to the plant if it is
left uncontrolled. The proposed new FOPID controller applies a time function to force the derivative gain to
take effect gradually, leading to a time-varying derivative FOPID (TVD-FOPID) controller, which maintains
a fast system response and signi?cantly reduces the voltage spike at the controller output. The time-varying
FOPID controller is optimally designed using the particle swarm optimization (PSO) or genetic algorithm
(GA) to ?nd the optimum constants and time-varying parameters. The improved control performance is
validated through controlling the closed-loop DC motor speed via comparisons between the TVD-FOPID
controller, traditional FOPID controller, and time-varying FOPID (TV-FOPID) controller which is created
for comparison with all three PID gain constants replaced by the optimized time functions. The simulation
results demonstrate that the proposed TVD-FOPID controller not only can achieve 80% reduction of voltage
spike at the controller output but also is also able to keep approximately the same characteristics of the system
response in comparison with the regular FOPID controller. The TVD-FOPID controller using a saturation
block between the controller output and the plant still performs best according to system overshoot, rise time,
and settling time.


Degree Type

  • Master of Science in Electrical and Computer Engineering


  • Electrical and Computer Engineering

Campus location

  • Hammond

Advisor/Supervisor/Committee Chair

Dr. Li-Zhe Tan

Additional Committee Member 2

Dr. Constantin Apostoaia

Additional Committee Member 3

Dr. David Kozel