Search results for " controller"
showing 10 items of 139 documents
Control of Flow Rate in Pipeline Using PID Controller
2019
In this paper a PID controller is utilized in order to control the flow rate of the heavy-oil in pipelines by controlling the vibration in motor-pump. A torsional actuator is placed on the motor-pump in order to control the vibration on motor and consequently controlling the flow rates in pipelines. The necessary conditions for asymptotic stability of the proposed controller is validated by implementing the Lyapunov stability theorem. The theoretical concepts are validated utilizing numerical simulations and analysis, which proves the effectiveness of the PID controller in the control of flow rates in pipelines.
The chaotic Dadras–Momeni system: control and hyperchaotification
2015
In this paper a novel three-dimensional autonomous chaotic system, the so called Dadras-Momeni system, is considered and two different control techniques are employed to realize chaos control and chaos synchronization. Firstly, the optimal control of the chaotic system is discussed and an open loop feedback controller is proposed to stabilize the system states to one of the system equilibria, minimizing the cost function by virtue of the Pontryagin’s minimum principle. Then, an adaptive control law and an update rule for uncertain parameters, based on Lyapunov stability theory, are designed both to drive the system trajectories to an equilibrium or to realize a complete synchronization of t…
A procedure to achieve fine control in MW processing of foods
2007
Abstract A two-dimensional analytical model for predicting the unsteady temperature field in a cylindrical shaped body affected by spatially varying heat generation is presented. The dimensionless problem is solved analytically by using both partial solutions and the variation of parameters techniques. Having in mind industrial microwave heating for food pasteurization, the easy-to-handle solution is used to confirm the intrinsic lack of spatial uniformity of such a treatment in comparison to the traditional one. From an experimental point of view, a batch pasteurization treatment was realized to compare the effect of two different control techniques both based on IR thermography readout: t…
A Computer Control System for the Hydraulic Stand MZPK 100 for Biaxial Fatigue Testing
2006
This paper presents a two-channel digital control system for the hydraulic stand MZPK 100 designed for fatigue tests of cruciform specimens under biaxial tension-compression. In the past, the fatigue test stand MZPK 100 was provided with unreliable analog control power cubicles. Application of the computer with an analog and digital input-output signal path board, Matlab/Simulink software and a new control box equipped with the necessary electronic subassemblies (responsible for proper switching of the hydraulic supplier, command electrovalves, conditioning of signals from sensors and so on) enables replacement of the old analog system by a new two-channel digital control system. Nowadays, …
Predictive dead time controller for GaN-based boost converters
2017
A dynamic dead time controller is presented, specifically intended to operate in synchronous boost converters based on GaN field-effect transistor switches. These transistors have a reduced stored charge with respect to silicon metal–oxide–semiconductor field-effect transistors with similar breakdown voltage and series resistance, and can operate at higher frequencies with reduced switching losses. On the other hand, the voltage drop in reverse conduction is typically more than doubled with respect to silicon devices resulting in relevant power losses during the free-wheeling phases. Therefore, dynamic control of dead time can be profitably applied even in converters operating in the tens o…
Stick-slip and convergence of feedback-controlled systems with Coulomb friction
2020
An analysis of stick-slip behavior and convergence of trajectories in the feedback-controlled motion systems with discontinuous Coulomb friction is provided. A closed-form parameter-dependent stiction region, around an invariant equilibrium set, is proved to be always reachable and globally attractive. It is shown that only asymptotic convergence can be achieved, with at least one but mostly an infinite number of consecutive stick-slip cycles, independent of the initial conditions. Theoretical developments are supported by a number of numerical results with dedicated convergence examples.
An improved sampling strategy based on trajectory design for application of the Morris method to systems with many input factors
2012
[EN] In this paper, a revised version of the Morris approach, which includes an improved sampling strategy based on trajectory design, has been adapted to the screening of the most influential parameters of a fuzzy controller applied to WWTPs. Due to the high number of parameters, a systematic approach has been proposed to apply this improved sampling strategy with low computational demand. In order to find out the proper repetition number of elementary effects of each input factor on model output (EEi) calculations, an iterative and automatic procedure has been applied. The results show that the sampling strategy has a significant effect on the parameter significance ranking and that rando…
Safety Assurance of a High Voltage Controller for an Industrial Robotic System
2020
Abstract Due to the risk of discharge sparks and ignition, there are strict rules concerning the safety of high voltage electrostatic systems used in industrial painting robots. In order to assure that the system fulfils its safety requirements, formal verification is an important tool to supplement traditional testing and quality assurance procedures. The work in this paper presents formal verification of the most important safety functions of a high voltage controller. The controller has been modelled as a finite state machine, which was formally verified using two different model checking software tools; Simulink Design Verifier and RoboTool. Five safety critical properties were specifie…
Visual servo control using orthinormal polynomial
2003
This paper describes an application of the visual servoing approach to vision-based control in robotics. The basic idea addresses the use of a vision sensor in the feedback loop within the controlled vision framework. It consists in tracking of arbitrary 3-D objects travelling at unknown velocities in a 2-D space (depth is given as known). Once the necessary modeling stage is performed, the framework becomes one of automatic control, and naturally stability, performance and robustness questions arise. Here, we consider to track line segments corresponding to the edges extracted from the image being analyzed. Two representations for a line segment are presented and discussed, and an appropri…
Nonlinear Modeling of DC/DC Converters Using the Hammerstein's Approach
2007
This paper deals with the modelling of highly nonlinear switching power-electronics converters using black-box identification methods. The duty cycle and the output voltage are chosen, respectively, as the input and the output of the model. A nonlinear Hammerstein-type mathematical model, consisting of a static nonlinearity and a linear time-invariant model, is considered in order to cope with the well-known limitations of the more common small-signal models, i.e. the entity of the variations of the variables around a well-defined steady-state operating point and the incorrect reproduction of the steady-state behavior corresponding to input step variations from the above steady-state operat…