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.

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.

scholarly journals Global adaptive partial state feedback tracking control of rigid-link flexible-joint robots

Robotica ◽  
2000 ◽  
Vol 18 (3) ◽  
pp. 325-336 ◽  
Author(s):  
W.E. Dixon ◽  
E. Zergeroglu ◽  
D.M. Dawson ◽  
M.W. Hannan
Keyword(s):  
State Feedback ◽  
Robot Manipulator ◽  
Parametric Uncertainty ◽  
State Feedback Control ◽  
Velocity Measurements ◽  
Linear Filters ◽  
Flexible Joint ◽  
Rigid Link ◽  
Flexible Joint Robots ◽  
Partial State

This paper presents a solution to the global adaptive partial state feedback control problem for rigid-link, flexible-joint (RLFJ) robots. The proposed tracking controller adapts for parametric uncertainty throughout the entire mechanical system while only requiring link and actuator position measurements. A nonlinear filter is employed to eliminate the need for link velocity measurements while a set of linear filters is utilized to eliminate the need for actuator velocity measurements. A backstepping control strategy is utilized to illustrate global asymptotic link position tracking. An output feedback controller that adapts for parametric uncertainty in the link dynamics of the robot manipulator is presented as an extension. Experimental results are provided as verification of the proposed controller.

Active Control of Combustion Instability Using Symmetric and Asymmetric Premix Fuel Modulation

2007 ◽  
Author(s):  
Daniel Guyot ◽  
Christian Oliver Paschereit
Keyword(s):  
Heat Release ◽  
Closed Loop ◽  
Modulation Frequency ◽  
Combustion Instability ◽  
Open Loop ◽  
Closed Loop Control ◽  
Nox Emissions ◽  
Loop Control ◽  
Asymmetric Modulation ◽  
Control Schemes

Active instability control was applied to an atmospheric swirl-stabilized premixed combustor using open loop and closed loop control schemes. Actuation was realised by two on-off valves allowing for symmetric and asymmetric modulation of the premix fuel flow while maintaining constant time averaged overall fuel mass flow. Pressure and heat release fluctuations in the combustor as well as NOx, CO and CO2 emissions in the exhaust were recorded. In the open loop circuit the heat release response of the flame was first investigated during stable combustion. For symmetric fuel modulation the dominant frequency in the heat release response was the modulation frequency, while for asymmetric modulation it was its first harmonic. In stable open loop control a reduction of NOx emissions due to fuel modulation of up to 19% was recorded. In the closed loop mode phase-shift control was applied while triggering the valves at the dominant oscillation frequency as well as at its second subharmonic. Both, open and closed loop control schemes were able to successfully control a low-frequency combustion instability, while showing only a small increase in NOx emissions compared to, for example, secondary fuel modulation. Using premixed open loop fuel modulation, attenuation was best when modulating the fuel at frequencies different from the dominant instability frequency and its subharmonic. The performance of asymmetric fuel modulation was generally slightly better than for symmetric modulation in terms of suppression levels as well as emissions. Suppression of the instability’s pressure rms level of up to 15.7 dB was recorded.

DESIGN OF ROBUST STATE FEEDBACK CONTROLLERS FOR REHABILITATION IN PARKINSONS TREMOR: A SIMULATION STUDY WITH UNCERTAIN MODEL OF BASAL GANGLIA

2016 ◽  
Vol 28 (04) ◽  
pp. 1650026
Author(s):  
K. Rouhollahi ◽  
M. Emadi Andani ◽  
S. M. Karbassi ◽  
M. Mojiri
Keyword(s):  
Basal Ganglia ◽  
State Feedback ◽  
Health Condition ◽  
Open Loop ◽  
The Other ◽  
Pole Placement ◽  
Neurosurgical Procedures ◽  
Loop Control ◽  
Disease Condition ◽  
Loop Control System

Deep brain stimulation (DBS) is one of the most effective neurosurgical procedures to reduce Parkinsons tremor. The conventional method of DBS is open loop stimulation of one area of basal ganglia (BG). On the other hand, existing feedback causes the reduction of additional stimulatory signal delivered to the brain which results in the reduction of the side effects caused by the excessive stimulation intensity. Actually, the stimulatory intensity of the controllers is reduced proportionally by the reduction of hands tremor, which is in fact the intended rehabilitation of the disease. The meaningful objective of this study is to design an architecture of controllers to decrease three criteria. The first one is the hand’s tremor, the second one is the level of delivered stimulation signal to brain in disease condition and the third one is the ratio of the level of delivered stimulation signal in health condition to disease condition. In order to achieve these objectives, a new architecture of a closed loop control system to stimulate two areas of BG at the same time is presented. One area (STN: subthalamic nucleus) is stimulated with a state feedback (SF) controller (pole placement method) and the other area (GPi: globus pallidus internal) is stimulated with a partial state feedback controller (PSFC). Considering these criteria, the results illustrate that stimulating two areas leads to a suitable performance. Simulation results show that the PSF and SF controllers are robust enough to the variations of the system parameters. Moreover, we are able to estimate the parameters of BG model in real time; it is a valuable method to update the time variable parameters of this model.

One-Player Differential Games

2017 ◽  
Author(s):  
João P. Hespanha
Keyword(s):  
Dynamical System ◽  
Differential Games ◽  
Continuous Time ◽  
Information Structure ◽  
Dynamic Games ◽  
State Feedback ◽  
Open Loop ◽  
Linear Quadratic ◽  
Time Dynamic ◽  
Termination Time

This chapter focuses on one-player continuous time dynamic games, that is, the optimal control of a continuous time dynamical system. It begins by considering a one-player continuous time differential game in which the (only) player wants to minimize either using an open-loop policy or a state-feedback policy. It then discusses continuous time cost-to-go, with the following conclusion: regardless of the information structure considered (open loop, state feedback, or other), it is not possible to obtain a cost lower than cost-to-go. It also explores continuous time dynamic programming, linear quadratic dynamic games, and differential games with variable termination time before concluding with a practice exercise and the corresponding solution.

A Parametrically Amplified MEMS Gyroscope

2010 ◽  
Vol 2010 (DPC) ◽  
pp. 001322-001334
Author(s):  
Barry J. Gallacher ◽  
Z. X. Hu ◽  
J. S. Burdess ◽  
K. M. Harish
Keyword(s):  
Open Loop ◽  
Parametric Amplification ◽  
Vibration Modes ◽  
Q Factor ◽  
Amplitude Control ◽  
Mems Gyroscope ◽  
Primary Mode ◽  
Harmonic Forcing ◽  
Control Schemes ◽  
Order Of Magnitude

The applicability of parametric amplification of either the primary and secondary vibration modes of a MEMS gyroscope, shown in Fig.1 is investigated experimentally in this paper. All control schemes have been implemented digitally onto a SHARC DSP development board. Parametric gains in excess of 80, which correspond to multiplication of the Q-factor by a factor of 80, are demonstrated experimentally for open-loop operation of the primary mode and are shown in Fig. 2. For open-loop operation it is shown that amplitude limiting nonlinearities become important as the vibration amplitude increases (see Figs.3) and that parametric amplification in excess of 80 can be only be achieved by further reducing the harmonic forcing amplitude. In many applications it is desirable to have as high a Q-factor as possible. The rate gyroscope is one application were active control of the Q-factor is extremely pertinent. If applied to the primary mode then it permits reduced forcing levels and hence contamination from “feedthrough”. If applied to the sense mode then the Coriolis force is effectively amplified. Parametric amplification of the secondary mode of the gyroscope is a challenging problem but it has the potential to improve the performance of MEMS rate gyroscope but an order of magnitude. In operation as a rate gyroscope it is important to maintain the amplitude of the primary mode of vibration at a constant level. For the case of a parametrically amplified primary mode the amplitude control circuit automatically adjusts the parametric excitation parameters to ensure the required parametric gain is achieved whilst at the same time reducing the amplitude of the harmonic forcing. In closed loop parametric amplification of the primary mode by a factor 20 have been demonstrated. Experimental results obtained from the amplified primary mode are shown in Fig.4.

Simulation and Control of a Commercial Double Effect Evaporator: Tomato Juice

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Praveen Yadav ◽  
Amiya K Jana
Keyword(s):  
Double Effect ◽  
Open Loop ◽  
Simulation Experiments ◽  
Loop Control ◽  
Process Dynamics ◽  
Point Tracking ◽  
Tomato Paste ◽  
Control Schemes ◽  
And Control ◽  
Gain Scheduled

This work aims to present a detailed study on a commercial double-effect tomato paste evaporation system. The modeling equations formulated for process simulation belong to backward feeding arrangement. Open-loop process dynamics has been studied by rigorous simulation of the model structure. In the next, three multi-loop control schemes, namely conventional proportional integral (PI), gain-scheduled PI (GSPI) and nonlinear PI (NLPI), have been synthesized for the sample process. Finally, several simulation experiments have been conducted to investigate the comparative closed-loop performance based on set point tracking and disturbance rejection.

Open-loop shape control for continuous microelectromechanical system deformable mirror

2010 ◽  
Vol 49 (31) ◽  
pp. G148 ◽  
Author(s):  
Alioune Diouf ◽  
Andrew P. Legendre ◽  
Jason B. Stewart ◽  
Thomas G. Bifano ◽  
Yang Lu
Keyword(s):  
Shape Control ◽  
Open Loop ◽  
Deformable Mirror ◽  
Microelectromechanical System ◽  
Loop Shape
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