Applied Mechanics and Materials Vols. 789-790

Abstract: This paper addresses a two-degree-of-freedom control system design for positioning de-vices such as table drive systems based on the predictive functional control (PFC). The aim of the paper is to improve the tracking performance of the previously developed disturbance observer-based predictive functional control (DOB-PFC) system. To this end, we derive a transfer function representation of the PFC controller. On the basis of the representation, we apply the zero phase error tracking controller (ZPETC) as a feedforward preview controller. Experiments using a real table drive system are conducted to compare the proposed control system with DOB-PFC. The experimental results show that the tracking error is greatly reduced compared to DOB-PFC.

Abstract: In this paper, a new decentralized adaptive output feedback variable structure control scheme is designed for mismatched uncertain large-scale systems where the exogenous disturbance is unknown. The proposed approach uses output information completely in sliding surface and controller design. Therefore, conservatism is reduced and robustness is enhanced. Furthermore, the reduce order system in sliding mode is asymptotically stable under certain conditions. Finally, a numerical example is used to demonstrate the efficacy on the method.

Abstract: This paper addresses the issue of associating a concept of industrial smart grid technology for a reactive power control of reversible electric drives. The research focus was concerned with the theoretical analysis of active, reactive and apparent power by the main reversible electric drive of plate mill rolling stand. Typical features of power electric equipment of modern reversible electric drives allow us to develop the reactive power control. The reactive power control can be created out by using of back to back converters which connect the reversible electric drive with the supply mains. Experiments in the plate mill were carried at the difficult-to-form steel grade in the range of roughing and finish rolling. It was established that the reactive power generation can be used in the range of the roughing. The huge prospects of the reversible electric drives integration based on back to back converters in Industrial Smart Grid have been determined due to the fact that to control of reactive and apparent power flows.

Abstract: In this paper we consider the development of a ball-and-pipe system controlled by an Arduino-based PID controller designed and tuned numerically in MATLAB/Simulink environment. The controller achieves small overshoot and fast settling time. The system is intended to be used as a laboratory experiment in control systems theory courses.

Abstract: It is necessary to change the parameters of PID controller if the parameters of plants change or there are disturbances. Particle swarm optimization algorithm is a powerful optimization algorithm to find the global optimal values in the problem space. In this paper, the particle swarm optimization algorithm is used to identify the model of the plant and the parameter of digital PID controller online. The model of the plant is identified online according to the absolute error of the real system output and the identified model output. The digital PID parameters are tuned based on the identified model and they are adaptive if the model is changed. Simulations are done to validate the proposed method comparing with the classical PID controller.

Abstract: For the discrete linear time-varying systems we present basic facts and definitions concerning the Lyapunov transformation, kinematic similarity and reducibility in the context of stability and Lyapunov exponents theory. Moreover, the paper contains the original result giving the necessary and sufficient conditions for the reducibility of a system to system with identity matrix.

Abstract: Air conditioners are one of the highest power consuming devices in houses or industrial buildings. Most buildings require air conditioner to make offices, classrooms, public areas or rooms to meet the required thermal comfort. Split unit type air conditioners are widely used in Negara Brunei Darussalam and other ASEAN countries. Currently, prescheduled controllers for split-unit air conditioners are not available in the market. In order to reduce air conditioner power consumption, study have been done to measured energy saving by controlling air conditioning using prescheduled controller that designed which is suitable for fixed operation hours example offices, schools, shops and others. Result showed that average percentage of power saving using a prescheduled controller can be as high as 40%.

Abstract: The inverted pendulum system is a challenging control problem in the control theory, which continually moves away from a stable state. The paper presents the design of a Proportional-Integral-Derivative (PID) controller for a single-input multi-output (SIMO) inverted pendulum system and using the Bees Algorithm (BA) to obtain optimal gains for PID controllers. The Bees Algorithm optimizes the gains so that the controller can move the cart to a desired position with the minimum amount of the change in the pendulum’s angle from the vertically upright position during the movement. The tuning aim is to minimize the control responses of the cart’s position and the pendulum’s angle in time domain. MATLAB/Simulink simulation has been performed to demonstrate that the effects on the system performance of PID controllers with optimal gains. The obtained results show that the tuning method by using the Bees Algorithm produced PID controllers successfully within the controller design criteria. Following a description of the inverted pendulum system and the Bees Algorithm, the paper gives the obtained simulation results for the system demonstrating the efficiency of the design.

Abstract: In this paper we consider the finite-dimensional dynamical control system described by scalar semilinear ordinary differential state equation with variable delay. The semilinear state equation contains both pure linear part and nonlinear perturbation. We extend the concept of controllability on trajectory controllability for systems with point delay in control and in nonlinear term. Moreover, we present remarks and comments on the relationships between different concepts of controllability. Finally we propose the possible extensions.

Abstract: The Bohl exponents, similarly as Lyapunov exponents, are one of the most important numerical characteristics of dynamical systems used in control theory. Properties of the Lyapunov characteristics are well described in the literature. Properties of the second above-mentioned exponents are much less investigated in the literature. In this paper we show an example of two-dimensional discrete time-varying linear system with bounded coefficients for which the number of lower Bohl exponents of solutions may be greater than dimension of the system.