Quantitative Feedback Theory (QFT) is employed to achieve time domain specifications on the tip position of a hybrid actuated single-link flexible manipulator. The manipulator payload conditions are varied to assess the robustness of the synthesised control system to parametric uncertainty. A combination of QFT multi input multi output (MIMO) design methods 1 (nonsequential) and 2 (sequential) ...

This paper presents the design of a robust controller using the Quantitative Feedback Theory technique for an asymmetric hydraulic cylinder electro-hydraulic servo system based upon a linear, parametrically uncertain model in which some of the uncertainties reflect the variation of the parameters, and taking the external disturbance into account. After the derivation of a realistic nonlinear di...

Optimal control involves feedback problems with explicit plant data and performance criteria for which a solution is either synthesized or ruled out. H∞ optimal control is probably the most renowned technique in this class where the control synthesis procedure involves various iterations over weightings. In this paper we argue that the integration of optimal control synthesis and manual tuning ...

Optimal control involves feedback problems with explicit plant data and performance criteria for which a solution is either synthesized or ruled out. H = optimal control is probably the most renowned technique in this class where the control synthesis procedure involves various iterations over weightings. In this paper we argue that the integration of optimal control synthesis and manual tuning...

This paper presents theoritical and experimental design of a robust control based on quantitative feedback theory (QFT) approach to control deepness variations on cutting process for a spindle of lathe machine. The dynamics of a spindle is uncertain and varying due to deepness variation on cutting process. Practical design steps are explained in which QFT based conditions are assembled to obtai...

This paper presents a robust control scheme for a distributed solar collector (DSC) field. As DSC are systems subjected to strong disturbances (mainly in solar radiation and inlet oil temperature), a series feedforward is used as a part of the plant, so that the system to be controlled has one input (fluid flow) and one output (outlet temperature) as the disturbances are partially compensated b...

This work focuses on the problem of automatic loop shaping in the context of robust control. More specifically in the framework given by Quantitative Feedback Theory QFT , traditionally the search of an optimum design, a non convex and nonlinear optimization problem, is simplified by linearizing and/or convexifying the problem. In this work, the authors propose a suboptimal solution using a fix...

This paper represents the design of a Quantitative Feedback Theory (QFT) based controller for an unstable system with some desired performance specifications [1]. Here a controller and prefilter has been designed so that the given performance specifications like robust stability and robust tracking criterions can be achieved. In order to implement that, different algorithms have been used and t...

This paper proposes an optimization algorithm for the automatic design of robust PID controllers using Quantitative Feedback Theory (QFT) specifications. The proposed algorithm is based on a criterion to minimize the energy of the control effort. To illustrate the methodology, the pitch angle of a laboratory helicopter is used as a model application with structured uncertainty. The results show...

This paper presents the design of a robust controller for a vehicle air suspension system using Quantitative Feedback Theory (QFT). This study is primarily focused on control of linearized active air suspension system. For the purpose of simplicity, the dynamics of the air suspension system is modeled using a simple 2-DOF quarter car model. Uncertain dynamic system with different working condit...