Modeling and Vibration Control of a Drum-Type Washing Machine via MR Fluid Dampers

[[abstract]]In this paper, a multibody dynamic model is developed for a front loading type washing machine in details. This model is constructed for verifying the bearing model between the tub and drum, and for analyzing the suspension system composed by two springs and magnetorheological dampers between the case and basket. The obtained results help engineers to design washing machines efficiently.[[sponsorship]]National Taipei University of Technology[[conferencetype]]國際[[conferencedate]]20091127~20091129[[iscallforpapers]]Y[[conferencelocation]]Taipei, Taiwa

A Lyapunov Based Multi-level Controller for Semi-active Suspension System with an MRF Damper

[[abstract]]In this work, we study the implementation of magnetorheological fluid (MRF) to the semi-active suspension. Owing to the nonlinear hysteretic phenomenon, the analysis and synthesis of a controller are not trivial. The kinematic energy and spring potential function of the suspension system plus an integral term of the hysteretic component of an MR damper is chosen as the Lyaupnov function to verify the stability and dissipativity of the system. Then, a multi-level controller, which is constructed in virtue of stability analysis, turns out to be effective in vibration suppression. Through numerical examples, the controller is shown to be robust. In addition, the controller algorithm is simple and easy to implement, requiring only the measurements of relative displacement and velocity between sprung and unsprung masses, along with the damping force of the MR damper.[[notice]]補正完

An unified approach to missile guidance laws: A 3D extension

[[abstract]]Since the proportional navigation guidance law was first introduced, many of the researchers had proposed different methodologies to investigate the corresponding performances of all the existing guidance laws. In 1997, Yang and Yang introduced an unified approach, in that paper the authors found that under the proposed framework, all the existing guidance laws, namely TPN, IPN and PPN, are indeed special cases of the mentioned general guidance law. But their results were restricted to two dimensional space. In this paper, the author not only extends the results to three dimensional space, but also to GTPN, GIPN and PPN. Unlike conventional researchers, a modified polar coordinate (MPC) is adopted. It is shown that with the property of this modified polar coordinate, the number of differential equations required to describe the relative dynamics can be reduced from six to three, and all the terms of differential equations involve only products and additions of variables. For all the mentioned guidance laws in this paper, to describe the capture area we need only two transformed variables, while the third variable is required to provide the condition of finite turn rate.[[conferencetype]]國際[[conferencedate]]20020508~20020510[[iscallforpapers]]Y[[conferencelocation]]Alaska, Anchorage, US

An Adaptive Control for Rotating Stall and Surge of Jet Engines - A Function Approximation Approach

[[abstract]]Compressor instabilities such as surge and rotating stall are highly unwanted phenomena in operation of jet engines. This is because these two instabilities reduce the performance and cause damage to aircraft engines. In this study, we design a model reference adaptive controller based on the function approximation technique to stabilize these two instabilities. Based upon this scheme, the controller parameters neither are restricted to be constant nor the bounds should be available a priori. The functions of the controller parameters are assumed to be piecewise continuous and satisfy the Dirichlet? conditions. Furthermore expressing these controller parameters in a finite-term Fourier series, they can be estimated by updating the corresponding Fourier coefficients. A Lyapunov stability approach is implemented to provide the update laws for the estimation of those time-invariant coefficients and guarantees the output error convergence. Therefore, the adaptive controller requires less model information and maintains consistent performance for the system when some controller parameters are disturbed.[[conferencetype]]國際[[conferencedate]]20051212~20051215[[iscallforpapers]]Y[[conferencelocation]]Seville, Spai

Capture regions of GIPN guidance laws: a least square SVM approach

[[abstract]]In this paper, the expression of capture region of the general ideal proportional navigation (GIPN) missile guidance law is determined by a powerful classifier, least square support vector machine (LSSVM). To reduce the computational burden, an approximation of the Gaussian radial basis function is adopted to obtain the corresponding nonlinear feature mapping function. Through numerous numerical examples, it shows that the proposed technique is adequate for the determination of capture region. All the analysis of the relative dynamics between missile and target are performed in a line of sight (LOS) fixed natural coordinate. To have the capture region ready for LSSVM, all the state variables are transformed into the modified polar variables form. In addition, to reduce the number of independent variables, these modified polar variables are further non-dimensionalized. For simplicity, we assume that target's input acceleration is subject to independent saturation, while missile's input acceleration is subject to magnitude saturation[[conferencetype]]國際[[conferencedate]]20060614~20060616[[iscallforpapers]]Y[[conferencelocation]]Minneapolis, Minnesota, US

GLOBAL STABILIZATION OF SYSTEMS CONTAINING A DOUBLE INTEGRATOR USING A SATURATED LINEAR CONTROLLER

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57819/1/SatDoubleIntegFengIJRNC1999.pd

ANTI-WINDUP COMPENSATOR SYNTHESIS FOR SYSTEMS WITH SATURATION ACTUATORS

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57796/1/Anti-WindupCompensatorSynthesisforSystemswithSaturationActuators.pd

Non-Uniformity of Wafer and Pad in CMP: Kinematic Aspects of View

[[abstract]]In this paper, we analyze the non-uniformity of sliding distance on both wafer and polishing pad from kinematic point of view. Using the Fourier series expansion, we can show that in steady state the non-uniformity is determined by the ratio between rotary speeds of platen and wafer carrier (m), and the ratio of wafer radius to the distance between the center of platen and wafer (Rc/d). In general, the non-uniformity of wafer increases with |m| and Rc/d. An important observation for polishing pad is that in two particular ranges of the ratio m, the larger Rc/d produces the smaller non-uniformity. Then a ring type polishing pad is proposed for the purpose of improving the non-uniformity of both wafer and pad. However, it turns out that the result is much worse than we expected.[[conferencetype]]國際[[conferencedate]]20050608~20050610[[iscallforpapers]]Y[[conferencelocation]]Portland, US

The capture region of a general 3D TPN guidance law for missile and target with limited maneuverability

[[abstract]]A method is used to analyze the capture area of general 3D true proportional navigation (TPN) guidance laws. With the aid of the orthogonal by not orthonormal modified polar coordinate (MPC), and three modified polar variables (MPVs), the expression of relative dynamics between target and missile becomes simple, and no trigonometric functions are involved, which makes possible the analysis of capture region for both target and missile with limited maneuverability. It can be shown that the determination of the desired capture area requires only the first two of the MPVs no matter whether the maneuverability of missile and target are limited or not. The boundary of the capture region on the two MPVs phase plane can be shown is composed of stable, unstable manifolds and a particular trajectory which will be indicated in the context. For the case of unlimited missile acceleration and measurable target acceleration, the capture region can be found analytically, while for the other cases, the capture region can be obtained graphically[[notice]]20130320格式已修正by陸桂英[[conferencetype]]國際[[conferencedate]]20010625~20010627[[iscallforpapers]]Y[[conferencelocation]]Arlington, US

Maximum-entropy-type Lyapunov functions for robust stability and performance analysis

We present two Lyapunov functions that ensure the unconditional stability and robust performance of a modal system with uncertain damped natural frequency. Each Lyapunov function involves the sum of two matrices, the first being the solution to the so-called maximum-entropy equation and the second being a constant auxiliary portion. The significant feature of these Lyapunov functions is that the guaranteed robust stability region is independent of the weighting matrix, while the performance bounds are relatively tight compared to alternative approaches. Thus, these Lyapunov functions are less conservative than standard bounds that tend to be highly sensitive to the choice of state space basis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30697/1/0000342.pd