A Sealed System and Compressor Model for Optimal Control of Household Refrigerators

2012 ◽  
Author(s):  
Bahman Abbasi ◽  
Keith Wait ◽  
Michael Kempiak
Keyword(s):  
Optimal Control ◽  
Control Systems ◽  
Effective Means ◽  
Evaporator Temperature ◽  
Efficient Manner ◽  
Control Effort ◽  
Industry Standards ◽  
Flow Phenomena ◽  
And Performance ◽  
And Control

Increasingly stringent industry standards have posed significant challenges on manufacturers to enhance the design and performance of household refrigerators. One of the least expensive and most effective means of improving the system is optimizing the control strategy. Some of the most promising control systems, such as adaptive and optimal control methods, require an accurate model of the system to guide the control effort. However, the complexity and interconnectedness of thermal and refrigerant flow phenomena make developing modern control systems a particularly challenging aspect of designing refrigerators, in spite of many decades of research and development. There exist models to correlate the desired compartments’ temperatures to that of the evaporator coil. However, there is a lack of a general approach to translate the required evaporator temperature to a compressor speed that provides it in an energy efficient manner. This work introduces a method to make that connection. The technique developed in this work can be adjusted for implementation on various refrigerator sizes and platforms to help modulate and control the compressor speed in real time.

An LQ Approach to Active Control of Vibrations in Helicopters

1996 ◽  
Vol 118 (3) ◽  
pp. 482-488 ◽  
Author(s):  
Sergio Bittanti ◽  
Fabrizio Lorito ◽  
Silvia Strada
Keyword(s):  
Optimal Control ◽  
Active Control ◽  
Linear Quadratic ◽  
Control Effort ◽  
Vibration Effect ◽  
Suitable Definition ◽  
Lq Optimal Control ◽  
The One ◽  
Definition Of ◽  
And Control

In this paper, Linear Quadratic (LQ) optimal control concepts are applied for the active control of vibrations in helicopters. The study is based on an identified dynamic model of the rotor. The vibration effect is captured by suitably augmenting the state vector of the rotor model. Then, Kalman filtering concepts can be used to obtain a real-time estimate of the vibration, which is then fed back to form a suitable compensation signal. This design rationale is derived here starting from a rigorous problem position in an optimal control context. Among other things, this calls for a suitable definition of the performance index, of nonstandard type. The application of these ideas to a test helicopter, by means of computer simulations, shows good performances both in terms of disturbance rejection effectiveness and control effort limitation. The performance of the obtained controller is compared with the one achievable by the so called Higher Harmonic Control (HHC) approach, well known within the helicopter community.

On Co-Scheduling of Update and Control Transactions in Real-Time Sensing and Control Systems: Algorithms, Analysis, and Performance

2013 ◽  
Vol 25 (10) ◽  
pp. 2325-2342 ◽  
Author(s):  
Song Han ◽  
Kam-Yiu Lam ◽  
Jiantao Wang ◽  
Krithi Ramamritham ◽  
Aloysius K. Mok
Keyword(s):  
Control Systems ◽  
Real Time ◽  
And Performance ◽  
And Control

Optimal Control Design of a Bimorph Optical Beam Deflector

2001 ◽  
Author(s):  
Chang-Po Chao ◽  
Jeng-Sheng Huang ◽  
Ching-Lung Ou Yung ◽  
Rong-Fong Fung
Keyword(s):  
Optimal Control ◽  
Position Control ◽  
Angular Position ◽  
Control Design ◽  
Element Model ◽  
Optical Beam ◽  
Optimal Feedback Control ◽  
Central Position ◽  
Control Effort ◽  
And Control

Abstract The optical beam deflector is composed of two piezoelectric layers, one sandwiched brass layer in the middle with both ends clamped and a mirror attached to the upper surface of the top piezoelectric layer in the central position. This structure is designed to deflect the mirror to a certain angular position by applying external voltage supply to piezo-layers. This study proposes an optimal angular position control scheme of the attached mirror. The governing partial differential equations are first derived for the ensuing analysis and control design, which is followed by the establishment of finite element model in ten nodes specified at some longitudinal points of the optical beam deflector. In order to achieve a faster convergent rate for the deflector to reach the desired angular position, the optimal control of LQ regulator with final states fixed is employed to explore the possibility of shorter transient response and less cost of control effort and states. The optimal feedback control is obtained based on solving a dynamic Riccati equation backward in time. The numerical simulation results are finally provided to validate the theoretical control design.

Cybersecurity From Field to Host

2016 ◽  
Author(s):  
Lee A. Cysouw ◽  
Douglas C. Osburn ◽  
Nader M. Rabadi
Keyword(s):  
Best Practices ◽  
Control Systems ◽  
Cyber Security ◽  
Measurement Data ◽  
Cyber Attacks ◽  
Operating Costs ◽  
Data Monitoring ◽  
Industry Standards ◽  
And Control ◽  
Remote Communications

Remote communications to field devices for data monitoring and controls has greatly reduced operating costs, reduced downtime, and helped to optimize our industry. With the ever growing threat of cyber-attacks, the need for securing that data is becoming a more common topic of discussion. Whether collecting SCADA or Measurement data from the field, doing remote configuration, or even sitting dormant, it is important to keep the line of communication to your devices secure. This presentation will discuss potential threats and examples of cyber-attacks. It will cover industry standards, types of cyber security, and the importance and best practices for securing data for Measurement and/or SCADA and control systems.

scholarly journals OPTIMAL CONTROL REALIZATIONS OF LAGRANGIAN SYSTEMS WITH SYMMETRY

2011 ◽  
Vol 08 (07) ◽  
pp. 1627-1651 ◽  
Author(s):  
M. DELGADO-TÉLLEZ ◽  
A. IBORT ◽  
T. RODRÍGUEZ DE LA PEÑA
Keyword(s):  
Optimal Control ◽  
Control Systems ◽  
Optimal Control Problems ◽  
Lagrangian System ◽  
Control Problems ◽  
Lagrangian Systems ◽  
Explicit Realization ◽  
Control Equation ◽  
And Control

A new relation among a class of optimal control systems and Lagrangian systems with symmetry is discussed. It will be shown that a family of solutions of optimal control systems whose control equation are obtained by means of a group action are in correspondence with the solutions of a mechanical Lagrangian system with symmetry. This result also explains the equivalence of the class of Lagrangian systems with symmetry and optimal control problems discussed in [1, 2]. The explicit realization of this correspondence is obtained by a judicious use of Clebsch variables and Lin constraints, a technique originally developed to provide simple realizations of Lagrangian systems with symmetry. It is noteworthy to point out that this correspondence exchanges the role of state and control variables for control systems with the configuration and Clebsch variables for the corresponding Lagrangian system. These results are illustrated with various simple applications.

Design, Performance, and Economics of 50-kW and 500-kW Vertical Axis Wind Turbines

1983 ◽  
Vol 105 (4) ◽  
pp. 418-424 ◽  
Author(s):  
L. A. Schienbein ◽  
D. J. Malcolm
Keyword(s):  
Wind Turbine ◽  
Control Systems ◽  
Operating Cost ◽  
Vertical Axis ◽  
Cost Performance ◽  
Vertical Axis Wind Turbines ◽  
Charge Rate ◽  
And Performance ◽  
High Level ◽  
And Control

A review of the development and performance of the DAF Indal 50-kW vertical axis Darrieus wind turbine shows that a high level of technical development and reliability has been achieved. Features of the drive train, braking and control systems are discussed and performance details are presented. Details are also presented of a 500-kW VAWT that is currently in production. A discussion of the economics of both the 50-kW and 500-kW VAWTs is included, showing the effects of charge rate, installed cost, operating cost, performance, and efficiency.

Discrete-Time H2-Optimal Control for Hydraulic Position Control Systems

2007 ◽  
Author(s):  
Yang Lin ◽  
Yang Shi ◽  
Richard Burton
Keyword(s):  
Optimal Control ◽  
Control Systems ◽  
Discrete Time ◽  
Ad Hoc ◽  
Position Control ◽  
Experimental Studies ◽  
Design Procedure ◽  
Design Parameters ◽  
Practical Applications ◽  
And Control

Hydraulic position control systems play an important role in industrial automation. This paper explores the application of discrete-time H2-optimal control for a hydraulic position control system (HPCS). By minimizing the H2-norm of the system, the discrete-time robust H2-optimal control both stabilizes the plant and minimizes the root-mean-square of the servo position error simultaneously. The intuitive nature of this advanced approach helps to manage the selection of design parameters, whereas, classical methods provide less insight into strategies for parameter selection and control design. Additionally, the powerful ability to address disturbances and uncertainty in the robust H2-optimal design offers a more direct alternative to the ad hoc and iterative nature of classical methods for the hydraulic servo position system. Computer simulations illustrate the design procedure and the effectiveness of the proposed method. Experimental studies which employ the H2-optimal control on a hydraulic positioning system are also conducted and the results show that the method is suitable for practical applications.

scholarly journals Maxwell Points of Dynamical Control Systems Based on Vertical Rolling Disc—Numerical Solutions

Robotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 88
Author(s):  
Marek Stodola ◽  
Matej Rajchl ◽  
Martin Brablc ◽  
Stanislav Frolík ◽  
Václav Křivánek
Keyword(s):  
Optimal Control ◽  
Control Systems ◽  
Optimal Control Problems ◽  
Numerical Solutions ◽  
Control Problems ◽  
Affine Control Systems ◽  
Dynamical Control ◽  
And Control ◽  
Analytical Approaches ◽  
Maxwell Points

We study two nilpotent affine control systems derived from the dynamic and control of a vertical rolling disc that is a simplification of a differential drive wheeled mobile robot. For both systems, their controllable Lie algebras are calculated and optimal control problems are formulated, and their Hamiltonian systems of ODEs are derived using the Pontryagin maximum principle. These optimal control problems completely determine the energetically optimal trajectories between two states. Then, a novel numerical algorithm based on optimisation for finding the Maxwell points is presented and tested on these control systems. The results show that the use of such numerical methods can be beneficial in cases where common analytical approaches fail or are impractical.

scholarly journals Socio-Organo Complexity, Project Schedule Performance and Underdamped Transient Motion

2020 ◽  
Vol 9 (4) ◽  
pp. 1-15
Author(s):  
Dimitris N. Antoniadis
Keyword(s):  
Project Management ◽  
Control Systems ◽  
Project Performance ◽  
Project Schedule ◽  
Management Processes ◽  
Project Complexity ◽  
And Performance ◽  
And Control ◽  
Made In ◽  
Main Factor

Complexity is an inherent property of all systems and a result of interconnections. In projects various systems come together to deliver the required outcome(s). The most common type of project complexity mentioned / considered in practice is the technical complexity and this has always been considered a main factor which affects project performance. Despite that, projects are delivered by people who interface ontinuously and therefore are effected by complexity, and in particular that caused by socio-organo interfaces and the boundaries between the various teams and parties. This has not been investigated. ocio-organo complexity leads to reduction in performance if interconnections are not managed. Research has been carried out to understand the effects of complexity through project management processes on project schedule and performance, aiming towards the development of a tool and identification of actions that will enable the management of these effects. The author presents results of five case studies, which demonstrate that socio-organo complexity affects performance and these results have similarities with the behaviour of underdamped control systems. The results have significant implications on the way socioorganisational complexity can be managed, how processes are implemented, but also enable parallels to be drawn between the fields of project management and control systems. Considering control systems theory proposals are made in this paper for actions to be taken which will contribute towards the management of the effects of socio-organo complexity on projects.

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