Abstract: State Dependent Riccati Equation (SDRE) approach is
a modification of the well studied LQR method. It has the capability of being applied to control nonlinear systems. In this paper the technique
has been applied to control the single inverted pendulum (SIP) which represents a rich class of nonlinear underactuated systems. SIP
modeling is based on Euler-Lagrange equations. A procedure is developed
for judicious selection of weighting parameters and constraint handling. The controller designed by SDRE technique here gives better results than existing controllers designed by energy based techniques.
Abstract: A nonlinear optimal controller with a fuzzy gain
scheduler has been designed and applied to a Line-Of-Sight (LOS)
stabilization system. Use of Linear Quadratic Regulator (LQR)
theory is an optimal and simple manner of solving many control
engineering problems. However, this method cannot be utilized
directly for multigimbal LOS systems since they are nonlinear in
nature. To adapt LQ controllers to nonlinear systems at least a
linearization of the model plant is required. When the linearized
model is only valid within the vicinity of an operating point a gain
scheduler is required. Therefore, a Takagi-Sugeno Fuzzy Inference
System gain scheduler has been implemented, which keeps the
asymptotic stability performance provided by the optimal feedback
gain approach. The simulation results illustrate that the proposed
controller is capable of overcoming disturbances and maintaining a
satisfactory tracking performance.
Abstract: In the control theory one attempts to find a controller
that provides the best possible performance with respect to some
given measures of performance. There are many sorts of controllers
e.g. a typical PID controller, LQR controller, Fuzzy controller etc. In
the paper will be introduced polynomial controller with novel tuning
method which is based on the special pole placement encoding
scheme and optimization by Genetic Algorithms (GA). The examples
will show the performance of the novel designed polynomial
controller with comparison to common PID controller.
Abstract: In this article, LQR based PID controller design for
3DOF helicopter system is investigated. The 3-DOF helicopter
system is a benchmark laboratory model having strongly nonlinear
characteristics and unstable dynamics which make the control of such
system a challenging task. This article first presents the mathematical
model of the 3DOF helicopter system and then illustrates the basic
idea and technical formulation for controller design. The paper
explains the simple approach for the approximation of PID design
parameters from the LQR controller gain matrix. The simulation
results show that the investigated controller has both static and
dynamic performance, therefore the stability and the quick control
effect can be obtained simultaneously for the 3DOF helicopter
system.