ABSTRACT
This paper investigates local and global bifurcation phenomena in a power system with two cascaded Load Tap Changer transformers. These devices regulate voltage at two different voltage levels. Conditions for oscillatory behavior and the stability of the system are extracted. The interaction between the two devices is also considered. More specifically, it is shown how the cascaded time constants influence the monotonic or oscillatory behavior of the system and the formation of a homoclinic loop bifurcation.
Key Words. Power system control, cascaded regulators, bifurcations, limit cycle, homoclinic loop.
ABSTRACT
In this paper, a novel approach is developed for global asymptotic stablization of Ghen's chaotic system, which in priciple works for other complex nonlinear systems as well. Based on a recently introduced methodology of inverse optimal control for nonlinear systems, a very simple stabilization control law is derived for the desired global asymptotic stabilization. Computer simulation is given for illustration and verification.
Keywords: Chaos, Nonlinear Systems, Inverse Optimal Control, Stability.
ABSTRACT
This paper formulates the problem of determining the cutting mode and the control mode of the band saw. The focus of this paper is the measurement of the cutting speed. It describes the structure and the operation of a device developed by the authors for direct, contact less measurement of the band-saw speed, the feed speed of the material, for estimation of the ratio of these speeds, recording and primary processing of the measurement results. A mathematical model has been created and the possibility to make a system of ratio speed control based on the measurements done by the device.
Keywords: Band saw, digital data processing, measurement of speed, ratio speed control
ABSTRACT
The method of nonlocal stabilization of the program motion is developed under condition of incomplete information about vectors of state when some coordinates are unobservable.
ABSTRACT
In this paper there is presented a method for the determination of the time histories of the internal co-ordinates of a serial type robot when the end-effector is moving along a spatial trajectory. This allow us to command the trajectory of the end-effector practically along any trajectory in the three-dimensional space. The method presented is simple and can be used for any type of robot. There is also demonstrated the existence of the solutions for the problem mentioned above.
Key words. Industrial robot , Internal coordinates , Generation of trajectories , Control of the motion.
ABSTRACT
An augmented and minimal realization state space models are proposed for direct implementation of the discrete-time linear-quadratic regulator (DLQR) with measured not all the state variables but only the output of the plant. Both the models are related by means of original transformation with a rectangular matrix. Using this transformation it is shown that the resulting closet-loop (CL) system with dynamic output feedback regulator (DOFR) has the same stable roots of its characteristic equation as the CL system with state feedback and DLQR; the additional zero roots of the rst CL system generated by DOFR do not change its properties, essentially. Itisalsoshown that the CL system with DOFR realizes the optimal control with feedback from an augmented state, resulting from solving an appropriate DLQR problem.
Key Words. Linear-quadratic regulator; discrete-time systems; state space models; ob- servers.