Adaptive Stabilization of MEMS Relays

2008 ◽  
Author(s):  
Y. Bastani ◽  
M. S. de Queiroz
Keyword(s):  
Parametric Uncertainty ◽  
Open Loop ◽  
Adaptive Stabilization ◽  
Electrical Parameters ◽  
Nonlinear Dynamic Model ◽  
Microelectromechanical System ◽  
Lyapunov Approach ◽  
Control Scheme ◽  
Opening And Closing ◽  
Adaptive Stabilizer

An adaptive nonlinear stabilizer is introduced for uncertain, voltage-controlled, microelectromechanical system (MEMS) relays. The control construction follows a Lyapunov approach, and is based on a nonlinear dynamic model applicable to the two types of MEMS relays—electrostatic and electromagnetic. The adaptive stabilizer compensates for parametric uncertainty in all mechanical parameters and selected electrical parameters while ensuring asymptotic regulation of the electrode opening and closing. Simulations demonstrate the performance of the adaptive control scheme in comparison to the typical open-loop operation of the MEMS relay.

Lyapunov-Based Stabilization of MEMS Relays

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Y. Bastani ◽  
M. S. de Queiroz
Keyword(s):  
State Feedback ◽  
Parametric Uncertainty ◽  
Open Loop ◽  
Velocity Measurements ◽  
Electrical Parameters ◽  
Nonlinear Dynamic Model ◽  
Microelectromechanical System ◽  
Lyapunov Approach ◽  
Control Schemes ◽  
Opening And Closing

In this paper, nonlinear stabilizers are introduced for voltage-controlled microelectromechanical system (MEMS) relays. The control constructions follow a Lyapunov approach and are based on a nonlinear dynamic model applicable to the two types of MEMS relays—electrostatic and electromagnetic. Two control schemes are presented with the objectives of avoiding pull-in during the microrelay closing and improving the transient response during the microrelay opening. First, an adaptive state feedback stabilizer is proposed to compensate for parametric uncertainty in all mechanical parameters and selected electrical parameters while ensuring asymptotic regulation of the electrode opening and closing. Next, a model-based observer/stabilizer is proposed to account for the lack of velocity measurements. Simulations demonstrate the performance of the two control schemes in comparison to the typical open-loop operation of the MEMS relay.

scholarly journals Simulations and experimental evaluation of an active orthosis for interaction in virtual environments

2018 ◽  
Vol 145 ◽  
pp. 01006
Author(s):  
Mihail Tsveov ◽  
Pavel Venev ◽  
Dimitar Chakarov ◽  
Ivanka Veneva
Keyword(s):  
Virtual Environments ◽  
Impedance Control ◽  
Computer Experiments ◽  
Open Loop ◽  
Body Parts ◽  
Human Arm ◽  
Control Scheme ◽  
Force Reflection ◽  
Physical Quantities ◽  
Active Orthosis

In this work, the development of a human arm active orthosis is presented. The orthosis is designed primarily for training and rehabilitation in virtual environments.The orthosis system is intended for embodiment in virtual reality where it is allowing human to perceive forces at different body parts or the weight of lifted objects. In the paper the choice of a mechanical structure is shown equivalent to the structure of the human arm. A mechanical model of the orthosis arm as haptic device is built, where kinematic and dynamic parameters are evaluated. Impedance control scheme is selected as the most suitable for force refection at the hand or arm. An open-loop impedance controller is presented in the paper. Computer experiments are carried out using the dimensions of a real arm orthosis. Computer experiments have been carried out to provide force reflection by VR, according to virtual scenario. The conducted simulations show the range of the forces on the operator hand, orthosis can provide. The results of additional measurements and experimental evaluations of physical quantities in the interaction in a virtual environment are revealed in the paper.

scholarly journals Automatic locking of a parametrically resonating, base-excited, nonlinear beam

2021 ◽  
Author(s):  
Nir Ben Shaya ◽  
Izhak Bucher ◽  
Amit Dolev
Keyword(s):  
Relative Phase ◽  
Closed Loop ◽  
Dynamical Behavior ◽  
Open Loop ◽  
Vibration Modes ◽  
Nonlinear Structure ◽  
Nonlinear Beam ◽  
Loop Control ◽  
Control Scheme ◽  
Slender Beams

AbstractDescribed is a closed-loop control scheme capable of stabilizing a parametrically excited nonlinear structure in several vibration modes. By setting the relative phase between the spatially filtered response and the excitation, the open-loop unstable solution branches are stabilized under a 2:1 parametric excitation of a chosen mode of vibration. For a given phase, the closed-loop automatically locks on a limit cycle, through an Autoresonance scheme, at any desired point on the solution branches. Axially driven slender beams and nanowires develop large transverse vibration under suitable amplitudes and frequency base-excitation that are sensitive to small potential coupled field. To utilize such a structure as a sensor, stable and robust operation are made possible by the control scheme. In addition, an optimal operating point with large sensitivity to the sensed potential field can be set using phase as a tunable parameter. Detailed analysis of the dynamical behavior, experimental verifications, and demonstrations sheds light on some features of the system dynamics.

Implementation of Single-Phase Two-Switch Midpoint Unidirectional Multilevel Converter System

2018 ◽  
Vol 19 (4) ◽  
Author(s):  
Peethala Rajiv Roy ◽  
P. Parthiban ◽  
B. Chitti Babu
Keyword(s):  
Single Phase ◽  
Pulse Width Modulation ◽  
Low Voltage ◽  
Supply Voltage ◽  
Harmonic Distortion ◽  
Input Voltage ◽  
Open Loop ◽  
Current Control ◽  
Control Technique ◽  
Control Scheme

Abstract This paper deals with implementation of a single-phase three level converter system under low voltage condition. The frequency of the switches is made constant and involves change in ${t_{on}}$ and ${t_{off}}$ duration. For this condition the pulse width modulation control scheme for a single phase three level rectifier is developed to improve the power quality. The hysteresis current control technique is adopted to bring forth three-level PWM on the dc side of the bridge rectifier and to achieve high power factor and low harmonic distortion. Based on the proposed control scheme, the line current is driven to follow the sinusoidal current command which is in phase with the supply voltage. By using three-level voltage pattern the blocking voltage of each power device is clamped to half of the dc link voltage. The simulation and experimental results of 20W converter under low input voltage condition are shown to verify the circuit performance. Open loop simulation and hardware tests are implemented by applying a low voltage of 15 V(rms) on the input side.

scholarly journals Open-closed Iterative Learning Control Algorithm for Exoskeleton Rehabilitation Purposes

2019 ◽  
Vol 292 ◽  
pp. 01010
Author(s):  
Mihailo Lazarević ◽  
Nikola Živković ◽  
Darko Radojević
Keyword(s):  
Iterative Learning Control ◽  
Control Algorithm ◽  
Closed Loop ◽  
Learning Control ◽  
Open Loop ◽  
Iterative Learning ◽  
Control Law ◽  
Exact Linearization ◽  
Outer Loop ◽  
Control Scheme

The paper designs an appropriate iterative learning control (ILC) algorithm based on the trajectory characteristics of upper exosk el eton robotic system. The procedure of mathematical modelling of an exoskeleton system for rehabilitation is given and synthesis of a control law with two loops. First (inner) loop represents exact linearization of a given system, and the second (outer) loop is synthesis of a iterative learning control law which consists of two loops, open and closed loop. In open loop ILC sgnPDD2 is applied, while in feedback classical PD control law is used. Finally, a simulation example is presented to illustrate the feasibility and effectiveness of the proposed advanced open-closed iterative learning control scheme.

Modeling and Control of a Rotary Crane

1985 ◽  
Vol 107 (3) ◽  
pp. 200-206 ◽  
Author(s):  
Y. Sakawa ◽  
A. Nakazumi
Keyword(s):  
Feedback Control ◽  
Equilibrium State ◽  
Open Loop ◽  
The State ◽  
Control Input ◽  
Loop Control ◽  
Modeling And Control ◽  
Control Scheme ◽  
Rotary Crane ◽  
And Control

In this paper we first derive a dynamical model for the control of a rotary crane, which makes three kinds of motion (rotation, load hoisting, and boom hoisting) simultaneously. The goal is to transfer a load to a desired place in such a way that at the end of transfer the swing of the load decays as quickly as possible. We first apply an open-loop control input to the system such that the state of the system can be transferred to a neighborhood of the equilibrium state. Then we apply a feedback control signal so that the state of the system approaches the equilibrium state as quickly as possible. The results of computer simulation prove that the open-loop plus feedback control scheme works well.

Dynamic Nonlinear Feedback Control Applied to Improve Butanol Production by Clostridium acetobutylicum

2017 ◽  
Vol 15 (6) ◽  
Author(s):  
H. I Velázquez-Sánchez ◽  
G. Lara-Cisneros ◽  
R. Femat ◽  
R. Aguilar-López
Keyword(s):  
Clostridium Acetobutylicum ◽  
Numerical Experiments ◽  
Closed Loop ◽  
Open Loop ◽  
Feedback Signal ◽  
Butanol Production ◽  
Nonlinear Feedback ◽  
Operational Conditions ◽  
Continuous Bioreactor ◽  
Control Scheme

Abstract The goal of this work is to present a closed-loop operational strategy in order to improve the butanol production in an anaerobic continuous bioreactor for the called Acetone-Butanol-Ethanol (ABE) process. The proposed control scheme considers a class of feedback signal which includes a nonlinear bounded function of the regulation error. The control scheme is applied to a phenomenological unstructured kinetic model obtained from an experimental and metabolic study of butanol production by Clostridium acetobutylicum, which allows the proposed structure to predict several operational conditions from batch and continuous regimes. Numerical experiments using the proposed model considering continuous operation were performed in order to find a feasible operating region for maximum butanol production at open-loop regime. The proposed methodology is applied to regulate the product concentration, manipulating the dilution rate to lead to a higher butanol productivity. The closed-loop behaviour of the bioreactor is analysed, finding that the proposed controller minimizes the response time of the system and allows it to achieve a productivity gain of 55 % over open-loop operation. Further numerical experiments show the satisfactory closed-loop performance of the proposed methodology in comparison with a PI controller.

scholarly journals Adaptive stabilization of continuous-time systems guaranteeing the controllability of a modified estimation model

2001 ◽  
Vol 7 (1) ◽  
pp. 29-54
Author(s):  
M. de la Sen
Keyword(s):  
Continuous Time ◽  
Switching Function ◽  
Adaptive Stabilization ◽  
Estimation Model ◽  
Switching Rule ◽  
Continuous Time Systems ◽  
Control Scheme ◽  
Positive Threshold ◽  
Time Systems ◽  
Plant Parameter

This paper presents an indirect adaptive control scheme for continuous-time systems. The estimated plant model is controllable while the estimation model is free from singularities. Such singularities are avoided through a modification of the estimated plant parameter vector so that its associated Sylvester matrix is guaranteed to be nonsingular. This property is achieved by ensuring that the absolute value of its determinant does not lie below a prescribed positive threshold. A switching rule is used in the estimates modification algorithm to ensure the controllability of the modified estimated model while avoiding possible chattering. For that purpose, the switching rule takes values at two possible distinct prefixed thresholds. In the event when the Sylvester determinant takes the current value of the switching function then that one switches to the alternative threshold. The convergence of both the unmodified and modified estimates to finite limits guarantees that switching ends in finite time. Thus, the solution to the controlled plant exist so that all the signals within the loop are well-posed.

scholarly journals Control System Based on Anode Offgas Recycle for Solid Oxide Fuel Cell System

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Shuanghong Li ◽  
Chengjun Zhan ◽  
Yupu Yang
Keyword(s):  
Control System ◽  
Decoupling Control ◽  
System Level ◽  
System Control ◽  
Electrical Characteristics ◽  
Electrical Parameters ◽  
Temperature Controller ◽  
Load Following ◽  
System Level Simulation ◽  
Control Scheme

The conflicting operation objectives between rapid load following and the fuel depletion avoidance as well as the strong interactions between the thermal and electrical parameters make the SOFC system difficult to control. This study focuses on the design of the decoupling control for the thermal and electrical characteristics of the SOFC system through anode offgas recycling (AOR). The decoupling control system can independently manipulate the thermal and electrical parameters, which interact with one another in most cases, such as stack temperatures, burner temperature, system current, and system power. Under the decoupling control scheme, the AOR is taken as a manipulation variable. The burner controller maintains the burner temperature without being affected by abrupt power change. The stack temperature controller properly coordinates with the burner temperature controller to independently modulate the stack thermal parameters. For the electrical problems, the decoupling control scheme shows its superiority over the conventional controller in alleviating rapid load following and fuel depletion avoidance. System-level simulation under a power-changing case is performed to validate the control freedom between the thermal and electrical characteristics as well as the stability, efficiency, and robustness of the novel system control scheme.

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