A Virtual Velocity Sensor for Improved Transient Performance of Electrostatically-Actuated MEMS

2003 ◽  
Author(s):  
D. H. S. Maithripala ◽  
Jordan M. Berg ◽  
W. P. Dayawansa
Keyword(s):  
Transient Behavior ◽  
Observer Design ◽  
Nonlinear Observer ◽  
Dynamics Simulation ◽  
Mems Devices ◽  
Electrostatically Actuated ◽  
Stabilizing Controllers ◽  
Bifurcation Phenomenon ◽  
Direct Sensing ◽  
Error Dynamics

Electrostatically-actuated MEMS devices suffer from a non-linear bifurcation phenomenon called “snap-through” or “pull-in.” This bifurcation severely limits the operating region of such devices. Control schemes have been proposed to eliminate snapthrough. These stabilizing controllers can be implemented using relatively straight forward current and voltage measurements. However, in order to alter the transient behavior of the system, for example to reduce settling time, or to minimize the likelihood of contacting the bottom electrode, the controller should also include terms dependent on the velocity of the movable electrode. Direct sensing of this velocity during normal device operation is typically not feasible. In this paper we show how the electrode velocity may be indirectly sensed using only capacitance and voltage measurements. Our approach is based on well known techniques of nonlinear observer design, and provides arbitrary fast linear error dynamics. Simulation results show excellent performance.

Nonlinear observer design via passivation of error dynamics

Automatica ◽  
2003 ◽  
Vol 39 (5) ◽  
pp. 885-892 ◽  
Author(s):  
H. Shim ◽  
J.H. Seo ◽  
A.R. Teel
Keyword(s):  
Observer Design ◽  
Nonlinear Observer ◽  
Error Dynamics

Control of an Electrostatic Microelectromechanical System Using Static and Dynamic Output Feedback

2004 ◽  
Vol 127 (3) ◽  
pp. 443-450 ◽  
Author(s):  
D. H. S. Maithripala ◽  
Jordan M. Berg ◽  
W. P. Dayawansa
Keyword(s):  
Output Feedback ◽  
Microelectromechanical Systems ◽  
Control Strategies ◽  
Output Feedback Control ◽  
Transient Behavior ◽  
Nonlinear Observer ◽  
Control Voltage ◽  
Reduced Order ◽  
Electrostatically Actuated ◽  
Dynamic Estimation

This paper examines control strategies for electrostatically actuated microelectromechanical systems (MEMS), with the goals of using feasible measurements to eliminate the pull-in bifurcation, robustly stabilize any desired operating point in the capacitive gap, decrease settling time, and reduce overshoot. We show that input-output linearization, passivity-based design, and the theory of port-controlled Hamiltonian systems lead naturally to static output feedback of device charge. This formalizes and extends previously reported results from the MEMS literature. Further analysis suggests that significantly improving transient behavior in lightly damped MEMS requires dynamic estimation of electrode velocity. We implement output-feedback control using a reduced-order nonlinear observer. Simulations predict greatly improved transient behavior, and large reductions in control voltage.

Robust nonlinear observer for forward kinematics solution of a Stewart platform: an experimental verification

Robotica ◽  
2000 ◽  
Vol 18 (6) ◽  
pp. 601-610 ◽  
Author(s):  
Dong Hwan Kim ◽  
Ji-Yoon Kang ◽  
Kyo-Il Lee
Keyword(s):  
Estimation Error ◽  
Stewart Platform ◽  
Observer Design ◽  
Nonlinear Observer ◽  
Forward Kinematics ◽  
Design Algorithm ◽  
Error Dynamics ◽  
The Stability ◽  
Robust Nonlinear Observer ◽  
Nonlinear Robust

A 6-DOF motion bed is proposed as a nonlinear robust observer to solve the forward kinematics problem of a Stewart platform. The stability of the estimation error dynamics is proved via Lyapunov stability analysis and the error dynamics shows practical stability. An observer design algorithm which tackles the nonlinearity and uncertainty both in the system and in the output is presented by a new arithmetic Riccati equation. The estimation performance for the algorithm is verified using both simulations and experiments. The equation employs the bounding condition computed from the platform dynamics.

A nonlinear fractional-order H∞ observer for SOC estimation of battery pack of electric vehicles

2021 ◽  
pp. 095440702199434
Author(s):  
Wei Yue ◽  
Cong-zhi Liu ◽  
Liang Li ◽  
Xiang Chen ◽  
Fahad Muhammad
Keyword(s):  
Fractional Order ◽  
Estimation Method ◽  
Equivalent Circuit Model ◽  
Lithium Ion ◽  
Open Circuit ◽  
Design Criterion ◽  
Observer Design ◽  
Nonlinear Observer ◽  
Battery Pack ◽  
Soc Estimation

This work is focused on designing a fractional-order [Formula: see text] observer and applying it into the state of charge (SOC) estimation for lithium-ion battery pack system. Firstly, a fractional order equivalent circuit model based on the fractional capacitor is established and identified. Secondly, the SOC estimation method based on the fractional-order [Formula: see text] observer is proposed. The nonlinear intrinsic relationship between the open-circuit voltage and SOC is described as a polynomial function, and its Lipschitz proposition has been discussed. Then, the nonlinear observer design criterion is established based on the Lyapunov method. Finally, the effectiveness of the proposed method is verified with high accuracy and robustness by the experiment results.

scholarly journals Reduced-order Nonlinear Observer Design for Two-time-scale Systems

2020 ◽  
Vol 53 (2) ◽  
pp. 5922-5927
Author(s):  
Zhaoyang Duan ◽  
Costas Kravaris
Keyword(s):  
Time Scale ◽  
Observer Design ◽  
Nonlinear Observer ◽  
Reduced Order

Observer Design for State Estimation of UV Curing Processes

2014 ◽  
Author(s):  
Adamu Yebi ◽  
Beshah Ayalew ◽  
Satadru Dey
Keyword(s):  
State Estimation ◽  
Online Monitoring ◽  
Uv Curing ◽  
Observer Design ◽  
Nonlinear Observer ◽  
Advanced Manufacturing ◽  
Monitoring And Control ◽  
State Observers ◽  
State Measurement ◽  
And Control

This article discusses the challenges of non-intrusive state measurement for the purposes of online monitoring and control of Ultraviolet (UV) curing processes. It then proposes a two-step observer design scheme involving the estimation of distributed temperature from boundary sensing cascaded with nonlinear cure state observers. For the temperature observer, backstepping techniques are applied to derive the observer partial differential equations along with the gain kernels. For subsequent cure state estimation, a nonlinear observer is derived along with analysis of its convergence characteristics. While illustrative simulation results are included for a composite laminate curing application, it is apparent that the approach can also be adopted for other UV processing applications in advanced manufacturing.

Average Modeling and Nonlinear Observer Design For Pneumatic Actuators With On/Off Solenoid Valves

2021 ◽  
Author(s):  
Khaled Laib ◽  
Minh Tu Pham ◽  
Xuefang LIN-SHI ◽  
Redha Meghnous
Keyword(s):  
Closed Loop ◽  
Sliding Mode ◽  
High Gain ◽  
Observer Design ◽  
Nonlinear Observer ◽  
State Model ◽  
Pressure Measurements ◽  
Pneumatic Actuators ◽  
Nonlinear Observers ◽  
Piston Position

Abstract This paper presents an averaged state model and the design of nonlinear observers for an on/off pneumatic actuator. The actuator is composed of two chambers and four on/off solenoid valves. The elaborated averaged state model has the advantage of using only one continuous input instead of four binary inputs. Based on this new model, a high gain observer and a sliding mode observer are designed using the piston position and the pressure measurements in one of the chambers. Finally, their closed-loop performances are verified and compared on an experimental benchmark.

Nonlinear observer based sliding mode control and oxygen fraction estimation for diesel engine

2017 ◽  
Vol 40 (7) ◽  
pp. 2227-2239 ◽  
Author(s):  
Haoping Wang ◽  
Qiankun Qu ◽  
Yang Tian
Keyword(s):  
Diesel Engine ◽  
Sliding Mode Control ◽  
Oxygen Concentration ◽  
Control Method ◽  
Sliding Mode ◽  
Observer Design ◽  
Nonlinear Observer ◽  
Linear Matrix ◽  
Model Based ◽  
Mode Control

In this paper, a nonlinear observer based sliding mode control (NOSMC) approach for air-path and a model-based observer for oxygen concentration in the diesel engine equipped with a variable geometry turbocharger and exhaust gas recirculation is introduced. We propose a less conservative observer design technique for Lipschitz nonlinear systems using Ricatti equations. The observer gains are obtained by solving the linear matrix inequality (LMI). Then a robust nonlinear control method, sliding mode control is applied for the states of intake and exhaust manifold pressure and compressor mass flow rate for the sake of the minimization of emissions. The proposed NOSMC controller is applied on a mean value model of turbocharged diesel engine. Besides this, a model-based observer is developed to estimate the oxygen concentration in the intake and exhaust manifolds owing to its significance in reducing emissions of diesel engines. The validation and efficiency of the proposed method are demonstrated by AMESim and Matlab/Simulink co-simulation results.

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