Control of a lamination process

A high-speed laminating machine for a fabric coating and conversion process is considered. Following analysis procedures, state-space and the admittance transfer function descriptions for the system are derived. Regulation of the fabric tension owing to heat shrinkage and environmental and coating variations is necessary. An optimum, minimum control effort strategy is proposed, enabling simple cost effective regulation, without the use of active elements. The speed of response of the system is improved by the use of feedback compensation. Design validation, via simulation, obtaining the open- and closed-loop system responses is employed, demonstrating the achievement of smooth, almost monotonic variations in tension following reference changes, as specified.

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Lipofilling to the Buttocks and Breasts in Local Anesthesia Using VASER and Expansion Vibration Lipofilling in a Closed-Loop System

The American Journal of Cosmetic Surgery ◽

10.1177/0748806820956498 ◽

2020 ◽

pp. 074880682095649

Author(s):

Roland Boeni ◽

Paul von Waechter-Gniadek

Keyword(s):

Local Anesthesia ◽

Large Volume ◽

Closed Loop ◽

Operation Time ◽

Cost Effective ◽

Fat Grafting ◽

Loop System ◽

Closed Loop System ◽

Satisfaction Rate ◽

Fat Extraction

Large-volume fat transfer to the buttocks and breast has rapidly become popular. Lipofilling using syringes is tedious, time-consuming, and carries the risk of contamination. Most often, systemic anesthesia is being used. This study aims to evaluate the efficacy of large-volume lipofilling in local anesthesia. Local anesthesia was performed with 2 anesthetics: lidocaine and prilocaine. We performed vibration amplification of sound energy at resonance (VASER) and reciprocating power-assisted liposuction (PAL) for fat collection in a closed-loop system using a peristaltic pump. In a reverse pump setting, fat was then used for expansion vibration lipofilling. Pre- and postoperative data were collected. There were no major complications. Liposuction volumes up to 3.100 mL were extracted, and injection volumes ranged from 200 to 1600 mL. Mean operation time was 96 minutes. Satisfaction rate was high. Anesthesia was sufficient in all patients. Using a closed-loop system for fat extraction–purification and transfer is not only time- and cost-effective but also ideal for large-volume fat grafting. Recovery time is 1 to 2 days and satisfaction rate is high.

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PMSM Servo System Control Based on Disturbance Observer

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.44-47.1090 ◽

2010 ◽

Vol 44-47 ◽

pp. 1090-1094

Author(s):

Hua Wei Chai ◽

Jin Yu Zhou ◽

Wei Ping Zhang ◽

Zhi Gang Li

Keyword(s):

Disturbance Observer ◽

High Speed ◽

Closed Loop ◽

Servo System ◽

System Control ◽

Strong Impact ◽

Closed Loop System ◽

Ac Servo System ◽

Ac Servo ◽

Speed Tracking

In order to realize high speed control of some ac servo system, aimed at all kinds of uncertain factors such as greatly changing moment and torque, and strong impact torque. Therefore, for gaining good speed tracking characteristics, adaptive disturbance observer is adopted to observe load torque disturbance and speed variation. Stability of closed loop system is guaranteed by design of control tractics to satisfy track control requests of rocket launcher servo system. Simulation results indicate that this method can ideally observe disturbance and reduce output of controller, thus control performance of the system is improved and is greatly meaningful.

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Optimal Redesign of Linear Systems

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.2801186 ◽

1996 ◽

Vol 118 (3) ◽

pp. 598-605 ◽

Cited By ~ 65

Author(s):

K. M. Grigoriadis ◽

G. Zhu ◽

R. E. Skelton

Keyword(s):

Quadratic Programming ◽

Linear Systems ◽

Covariance Matrix ◽

Active Control ◽

Closed Loop ◽

Controller Design ◽

Iterative Approach ◽

System Matrix ◽

Closed Loop System ◽

Control Effort

This paper proposes a redesign procedure for linear systems. We suppose that an initial satisfactory controller which yields the desired performance is given. Then both the plant and the controller are redesigned to minimize the required active control effort. Either the closed-loop system matrix or the closed-loop covariance matrix of the initial design can be preserved under the redesign. Convex quadratic programming solves this problem. In addition, an iterative approach for integrated plant and controller design is proposed, which uses the above optimal plant/controller redesign in each iterative step. The algorithm has guaranteed convergence and provides a sequence of designs with monotonically decreasing active control effort. Examples are included to illustrate the procedure.

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Intelligent Control of Uncertain PMSM Based on Stable and Adaptive Discrete-Time Neural Network Compensators

Journal Européen des Systèmes Automatisés ◽

10.18280/jesa.540407 ◽

2021 ◽

Vol 54 (4) ◽

pp. 575-589

Author(s):

Aziz El Janati El Idrissi ◽

Mohsin Beniysa ◽

Adel Bouajaj ◽

Mohammed Réda Britel

Keyword(s):

Neural Network ◽

Intelligent Control ◽

High Speed ◽

Closed Loop ◽

Permanent Magnet Synchronous Motor ◽

Closed Loop System ◽

Adaptive Neural Network ◽

Control Scheme ◽

On Line ◽

Classical Vector

In this paper, stable and adaptive neural network compensators are proposed to control the uncertain permanent magnet synchronous motor (PMSM). Firstly, the overall uncertainties caused by mathematical modelling, parameters variation during operation and external load torque disturbances are modelled. Secondly, a new motion control scheme, where (d-q) current loops are dotted by two on-line tuning neural network compensators (NNCs), is used to compensate these uncertainties. As a result, the speed control loop is processed easily by proportional integral (PI) controller. Stability of the closed-loop system is also designed according to the Lyapunov stability. Compared to classical vector control, the simulations of PMSM system at different speeds including nominal, low and high speed, with and without uncertainties, show the effectiveness of the proposed control scheme.

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Switching Antiwindup Design on Enlarging the Domain of Attraction for a Supercavitating Vehicle Subject to Actuator Saturation

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.4036230 ◽

2017 ◽

Vol 139 (9) ◽

Author(s):

Baochen Qiang ◽

Zhang Le

Keyword(s):

Optimization Problem ◽

Closed Loop ◽

Actuator Saturation ◽

Domain Of Attraction ◽

Inequality Constraints ◽

Linear Matrix ◽

Closed Loop System ◽

Supercavitating Vehicle ◽

Linear Differential ◽

Compensation Design

This paper presents a new switching antiwindup compensation design to maximize the domain of attraction for a supercavitating vehicle subject to actuator saturation. The dive-plane dynamics of the vehicle are considered. By applying the linear differential inclusion expression of saturated feedbacks, conditions under which the compensator locally stabilizes the closed-loop system are then derived. The design of antiwindup gains on maximizing the system's domain of attraction is finally formulated and solved as an iterative optimization problem with linear matrix inequality constraints. Simulations are conducted for systems with magnitude and rate limits to evaluate the effectiveness of the proposed method.

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Study on Mechanical Automation with Optimal Control for Four-Wheel-Active-Steer Vehicle

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.703.264 ◽

2013 ◽

Vol 703 ◽

pp. 264-268 ◽

Cited By ~ 1

Author(s):

Feng Du ◽

Zhi Wei Guan ◽

Guang Hui Yan

Keyword(s):

Optimal Control ◽

High Speed ◽

Closed Loop ◽

Response Characteristic ◽

Loop System ◽

Driver Model ◽

Closed Loop System ◽

Control Effect ◽

Sideslip Angle ◽

Active Steering

For improving the vehicle handling at high speed, an optimal controller was introduced for the four-wheel-active-steering vehicle. A closed-loop system was set up by combining vehicle model with driver model. The simulation test in the closed-loop system was carried out to verify control effect of such a optimum controller. Simulation results show that the four-wheel-active-steering vehicle under the optimal control can gain expected control effect such as wiping out sideslip angle and tracking desired yaw rate and so on. In addition, the four-wheel-active-steering vehicle with the optimal control can also track desired trajectory and its following accuracy is better than the traditional front-wheel steering vehicle. So, the steering response characteristic for the four-wheel-active-steering vehicle at high speed is improved.

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Yaw Dynamic Modeling for Improved High Speed Control of a Farm Tractor

10.1115/imece2000-2347 ◽

2000 ◽

Author(s):

David M. Bevly ◽

J. Christian Gerdes ◽

Bradford W. Parkinson

Keyword(s):

System Identification ◽

High Speed ◽

Closed Loop ◽

Dynamic Models ◽

Tracking Error ◽

Analytical Models ◽

Control Effort ◽

Farm Tractor ◽

Loop Bandwidth ◽

Lqr Controller

Abstract This paper presents the system identification of a farm tractor in order to improve automatic control at higher speeds and understand controller limitations from neglecting the yaw dynamics. Yaw dynamic models are developed for multiple speeds to show the effect of velocity on the model. The identified modeled yaw dynamics do not resemble any traditional analytical models. Additionally, the effect of velocity on the closed loop bandwidth of the controller for a given set of LQR controller weights is presented. Results are given that validate that as the closed loop bandwidth of LQR control weights approaches the regime of the unmodelled yaw dynamics, the controller can go unstable. Finally results show an improvement of the lateral tracking error (with a decrease in control effort) using the system identification model.

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