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This paper presents a novel hexapod robot with legs radially free distributed around the body. Compared with radial symmetric or rectangular symmetric robots, the legs of radially free distributed hexapod robot can rotate around the body of the robot and redistribute their positions thanks to the proposed radially free distribution mechanism. The kinematic model of the articulated leg mechanism is...
Passive theory has been paid much more attention since its debut for it has connection with physical properties and stability of the investigated systems. And, besides that, passive theory contributes for Lyapunov function further in part for its root in storage functions. On account of that, a new bridge between passivity and stability for non-autonomous systems is touched and built in this paper...
In this paper, a general design approach is proposed to derive the feedforward control law in feedback-feedforward control systems. This design approach is based on the concept of `control equilibrium point'. In this design approach, the feedback controller generates the transient control command and the feedforward controller generates the steady state one. Using the proposed feedforward controller,...
The semiconductor manufacturing industry increasingly requires cluster tools, which consist of several single-wafer processing modules, a wafer-handling robot, and loadlocks. Some processes, such as low-pressure chemical vapor deposition, require strict time window constraints due to residual gases and heat in the chamber. The cluster tool should be operated at a steady schedule to minimize the maximum...
Regrasp operations consist of a sequence of pick-and-place operations, which are very useful to avoid collisions with the environment and to overcome the kinematic limitations in some cases. In this work, we propose an automatic planning system for regrasp operations for a multifingered robotic hand. The stable planes of the object to be grasped are automatically found. The minimal angle allowed to...
The miniature unmanned helicopter exhibits a complex and nonlinear dynamic behavior, open- loop unstable and a high degree of inter-axis coupling. This paper describes a hybrid PID velocity control method based on single neuron for an unmanned helicopter. This method possesses both the simple structure of PID controller, and adjusting papameters on-line by intelligent technique. The application results...
This paper is aimed to application of simple continuous-time robust regulators of PI and PID type designed through general solutions of Diophantine equations in the ring of proper and stable rational functions to control of temperature in laboratory model of hot-air tunnel of which mathematical model is supposed to include parametric uncertainty. One of the main advantages of the proposed algebraic...
This paper deals with the design of reduced order observers for a class of nonlinear descriptor systems. The order of these observer is qlesn , where n is the dimension of the semi state. A new method is presented, the conditions for the existence of these observers are given and sufficient conditions for their stability are derived using linear matrix inequalities (LMIs) formulation. A numerical...
In this paper, we consider the dynamic modeling and the practical implementation of an autonomous dynamic positioning scheme, i.e., the stabilization of linear and angular velocities as well as the position and orientation, of a floating sea triangular platform. The required, closed-loop force and moment must be provided by three rotating pump jets, located at the bottom of three partly submerged...
This paper deals with the problems of robust admissibility and state feedback admissibilization of uncertain discrete descriptor systems. We propose a new sufficient condition, which is necessary in terms of a strict linear matrix inequality (LMI) for a nominal discrete descriptor system to be admissible (stable, regular and impulse free). Based on this, the state feedback admissibility problem is...
This paper deals with the physical modeling and the digital time simulation of acoustic pipes. We will study the simplified case of a single convergent cone. It is modeled by a linear system made of delays and a transfer function which represents the wave reflection at the entry of the cone. According to [1], the input/output relation of this system is causal and stable whereas the reflection function...
In this paper control theoretic approach is applied to design a new, optimal flow controller for multi-source connection-oriented communication networks. The networks are modeled as discrete time, n-th order systems. On the basis of the system state space description, a feedback control law is derived by minimizing linear quadratic (LQ) cost functional. Closed loop system stability is demonstrated,...
This paper presents a direct adaptive fuzzy control scheme for a class of uncertain single-input single-output nonlinear systems subject to input amplitude and rate saturation constraints. The fuzzy controller is designed to mimic an ideal controller which is assumed guarantying the control objective. The free parameters of the fuzzy controller are adjusted by an adaptive law which prevents the presence...
This paper focuses on the fragility analysis of PI-controllers for single-input-single-output (SISO) systems subject to input (or output) delays. Using a geometric approach, we present a simple and user-friendly approach not only to analyze the fragility of PI controllers, but also to provide practical guidelines for the design of non-fragile PI controllers. The proposed methodology is illustrated...
In this article, we propose the use of a Sigma - Delta modulation approach combined with an appropriate dualization of generalized proportional integral (GPI) control strategies for the design of observers undergoing switched output injections, as in remote state estimation cases. The class of switched injection sliding observers inherit their robustness with respect to un-modeled perturbation inputs...
Stability is the first demand of the feedback control design. The parametrization of all stabilizing controllers is standard theory. The stabilizing controller has some free parameters which can be used for further optimization. Linear Quadratic (LQ) control and Dead Beat control are standard algorithms for optimal control of discrete time models of real systems. The dead beat control results in very...
The Schur stability analysis of an interval polynomial family can be quickly performed through a unique, suitably defined extreme polynomial. The purpose of this paper is to provide some improvements with respect to the actually existing methods based on this approach.
The paper presents a method for adjusting power in wireless networks consisting of mobile users. The proposed methodology takes advantage of the system nonlinearity by coherently changing the stability of the system equilibria. A decentralized sliding mode based controller was introduced, for each node of the network, to control bifurcations. The control law tries to always maximize the Signal-to-Interference-Ratio...
This paper deals with modeling and design of reliable controller for a new type diaphragm pump. Because of parameter uncertainties and nonlinear dynamics of the pump model, a fuzzy-like PID controller is designed. The controller design is based on fuzzy Lyapunov synthesis and stability and the robustness analysis of the designed system are straightforward. The pump control system is driven by a digital...
The paper proposes a method for feedback stability evaluation for discrete-time, linear time-varying control systems. It is assumed that the time-varying system can be described by linear matrices operators, equivalent to general discrete-time, time-varying state space model with nonzero input-output delay. The main used tools are Bode diagrams approximated for time-varying systems, using power spectral...
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