This paper presents a new approach, called adaptive autocentering, that compensates for transmitted force due to imbalance in an active magnetic bearing system. Under the proposed control law, rigid rotor achieves rotation about mass center and principal axis of inertia. The basic principle this approach is perform on-line identification physical characteristics use results tune stabilizing controller. differs from usual strategy feedforward compensation, which models effect as external...

This paper serves three distinct purposes. First, it provides the problem statement for benchmark nonlinear control design, an invited session which is basis six related papers at conference. The considers a translational oscillator with attached eccentric rotational proof mass actuator, where coupling between motion of actuator and mechanism control. Secondly, describes experimental testbed that has been constructed by authors to experimentally investigate this problem. Finally, presents...

We demonstrate a dynamic vibration absorber system which can be used to reduce speed fluctuations in rotating machinery. The primary is modeled as simple disk, and the idealized consists of pair equal point masses are free move along identical, prescribed paths relative disk. unique features proposed arrangement that absorbers tuned one-half frequency applied torque and, more importantly, they effective fully nonlinear operating range. These can, undamped case, exactly cancel pure harmonic...

The oscillating eccentric rotor has been widely studied to model resonance capture phenomena occurring in dual-spin spacecraft and rotating machinery. This phenomenon arises during spin-up as a condition is encountered. We consider the related problem of despin. Specifically, we determine nonlinear feedback control laws that not only despin but also bring its translational motion rest. These globally asymptotically stabilizing are derived using partial linearization integrator backstepping...

Biochemical and biophysical stimuli of stem cell niches finely regulate the self-renewal/differentiation equilibrium. Replicating this in vitro is technically challenging, making control functions difficult. Cell derived matrices capture certain aspect that influence fate decisions. Here, aligned fibrous synthesized by MC3T3 cells were produced role matrix orientation stiffness on maintenance characteristics adipo- or osteo-genic differentiation murine mesenchymal (mMSCs) was investigated....

Abstract Wir wenden die Methode der Lie‐Transformationen, eine Perturbationsmethode für Differentialgleichungen, auf allgemeine Klasse von Hamilton‐Systemen an, wobei wir uns Computer‐Algebra bedienen. Dabei entwickeln (geschrieben in Sprache Koeffizienten im Ausgangssystem H) explizite Formeln zur Transformation des Systems Birkhoffsche Normalform. Unter Anwendung eines Satzes Arnold nichtlineare Stabilitätskriterien allein H Systeme, bei denen lineare Stabilitätsanalyse nicht schlüssig...

The aim of this work is to present a preliminary study for the design digital auscultation system, i.e., novel wearable device patient chest and stethoscope. development testing electronic stethoscope prototype reported with an emphasis on description selection sound transduction systems analog processing. focus various microphone technologies, such as micro-electro-mechanical (MEMSs), electret condensers, piezoelectronic diaphragms, intends emphasize most suitable transducer auscultation....

The problem of a spacecraft tracking desired trajectory is defined and addressed using adaptive feedback control. control law, which has the form sixth-order dynamic compensator, does not require knowledge inertia spacecraft. A Lyapunov argument used to show that achieved globally. simple spin about intermediate principal axis coning motion are commanded illustrate algorithm. Finally, periodic commands identify matrix

In recent the work of Wan et al. it was shown that a rotational torque actuator with attached eccentric mass can be used to globally stabilize one-mode translational oscillator. A family stabilizing nonlinear feedback control laws derived by using partial linearization and integrator backstepping. These accounted for strongly coupling between motion present paper, we extend these results address problem multi-mode systems actuator. The controller synthesis methodology extends previous system...

Extracellular matrix assembly and composition influence the biological mechanical functions of tissues. Developing strategies to control spatial arrangement cells is central importance for tissue engineering-related approaches relying on self-assembling scaffoldless processes. Literature reports demonstrated that signals patterned material surfaces are able cell positioning orientation. However, mechanisms underlying interactions between structure de novo synthesized far from being...

The rotational/translational actuator (RTAC) provides a low-dimensional nonlinear system for investigating control techniques. lossless formulation of this problem involves coupling an undamped oscillator with rotational rigid body mode. Stabilization and disturbance rejection objectives have been formulated as benchmark problem. We implement four controllers on the RTAC, including integrator backstepping controller three passivity-based controllers. design is based work Wan et al. (1996)....

Presents sufficient conditions which guarantee that a class of third order nonlinear control systems with time-dependent drift is controllable in slab. Assuming the controllability are satisfied authors construct function steers system from an arbitrary initial state slab to final over given period time.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

An experimental testbed for investigating control algorithms reducing or eliminating the effects of mass imbalance in rotating bodies has been designed and constructed. This moment gyro/gyropendulum allows researchers to experimentally demonstrate reorientation, stabilization vibration suppression.

The dynamical equations for a spinning top are derived in which the orientation is specified by complex variable using stereographic projection of Poisson's equations. Necessary and sufficient conditions Lyapunov stability uncontrolled motion given Energy-Casimir method. Control laws that globally asymptotically stabilize to sleeping two torque actuators then synthesized employing techniques from theory systems cascade form generalized Hamilton-Jacobi-Bellmann with zero dynamics.

Provides a tutorial exposition for the Energy-Casimir method and constructs Lyapunov function to prove stability systems having at least two integrals of motion. Stabilization intermediate axis rotation an asymmetric rigid spacecraft by applying input torque along minor or major is reconsidered. For axially symmetric spacecraft, authors construct linear applied symmetry which stabilizes about transverse principal axis.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML"...

The rotational dynamics and control of a planar system interconnected rigid bodies, referred to as multilink, are studied assuming that the annular momentum multilink is conserved. It demonstrated internal actuators can be used change orientation in desired time-varying fashion. theory developed paper applied spacecraft tracking problem, where modeled multilink.

Considers the problem of controlling a top in sleeping motion using two different actuation schemes. For fixed-base actuators are assumed to provide forces at center mass inertially fixed directions, while for cart-mounted apply cart directions. The controller is obtained from designed D'Alembert's principle. Both controllers proved be globally asymptotically stabilizing. uncontrolled base top, necessary and sufficient conditions Lyapunov stability derived.