Now showing 1 - 8 of 8
  • Publication
    A kicked oscillator as a model of a pulsed MEMS system
    (World Scientific Publishing, 2009-01) ;
    In this paper, we study the behaviour of a MEMS oscillator by applying methods of nonlinear dynamics. We model the system as a kicked damped oscillator and obtain the iterative maps that describe the MEMS system. The dynamics of the maps are studied numerically: we present a study of limit cycles and their rotation numbers and show how the control parameters and initial conditions may affect the output frequencies.
      617Scopus© Citations 9
  • Publication
    Pulsed Digital Oscillators for Electrostatic MEMS
    This paper introduces a new actuation scheme for implementing Pulsed Digital Oscillators (PDOs) for electrostatic MEMS resonators. In this scheme, the capacitance of the device is biased with a voltage and it is periodically sampled. Short pulses of zero voltage are applied depending on the decisions taken by the oscillator loop. The paper discusses in detail the implementation of such electrostatic PDO (e-PDO) through a prototype and links the e-PDO to the conventional PDO theory. As an example, it is shown that with this actuation scheme it is possible to excite different resonances of the mechanical structure simply by changing the parameters of the feedback filter of the oscillator.
      562Scopus© Citations 11
  • Publication
    On some properties of the output of a pulsed digital oscillator working with multiple resonances
    In this paper, we study the possible output of the pulsed digital oscillator (PDO) with multiple resonant modes of the mechanical resonator in the feedback loop. PDOs are simple circuits that allow linear resonators to maintain self-sustained oscillations and can work as mass-change resonant sensors. For a resonant sensor, activation of higher vibration modes of a mechanical resonator can be a way to improve its performance. We show that the location of the sensing/actuation system affects the output and can enhance higher mechanical modes.
      307Scopus© Citations 2
  • Publication
    Control of MEMS vibration modes with pulsed digital oscillators : part II — simulation and experimental results
    This paper extends our previous work on the selective excitation of mechanical vibration modes in MEMS devices using Pulsed Digital Oscillators. It begins by presenting extensive simulation results using the set of iterative maps that model the system and showing that it is possible to activate two or three spatial modes (resonances) of the mechanical structure with a Pulsed Digital Oscillator (PDO). The second part of this paper presents experimental results corroborating the theory and simulation results. It is shown that it is possible to separately excite vibration modes of the device by setting a few parameters of the PDO structure such as the sampling frequency and the sign of the feedback loop.
      300Scopus© Citations 12
  • Publication
    MEMS with sigma-delta type of feedback loop control as an iterative map
    In this work, we consider a system that consists of a microresonator and a ΣΔ type feedback loop control which is typically a part of inertial sensors. We describe this architecture as a dynamical system (an iterative difference equation) in the time domain in order to study possible periodic solutions in the output.
      312Scopus© Citations 1
  • Publication
    Dynamics of the MEMS pulsed digital oscillator with multiple delays in the feedback loop
    In this paper we apply methods of nonlinear dynamics to examine the behavior of the pulsed digital oscillator for microelectromechanical systems (MEMS). We study the regions of existence of oscillations and demonstrate the effect on these of including additional delays into the feedback loop.
      382Scopus© Citations 4
  • Publication
    Excitation of multiple spatial modes of a MEMS cantilever in the pulsed digital oscillator
    The aim of this paper is to apply an approach that will allow us to consider different mechanical modes of a MEMS cantilever in the form of separate mass-spring-damper equations with the appropriate form of an external driving. In the paper, we focus on a specific MEMS cantilever and use a Pulsed Digital Oscillator (PDO) to keep self-sustained oscillations of the mechanical structure. By applying the order-reduction procedure to a partial differential equation that describes the transversal deflections, we obtain a system of coupled ordinary differential equations that describes the excitation of multiple spatial modes. On the basis of these ordinary differential equations, we formulate a set of iterative maps to describe the evolution of the modes between two sampling events. The numerical simulations we present are focused on the most common case when the first two mechanical modes are taken into consideration
      346
  • Publication
    Control of MEMS vibration modes with Pulsed Digital Oscillators : Part I — theory
    The aim of this paper is to show that it is possible to excite selectively different mechanical resonant modes of a MEMS structure using Pulsed Digital Oscillators (PDOs). This can be done by simply changing the working parameters of the oscillator, namely its sampling frequency or its feedback filter. A set of iterative maps is formulated to describe the evolution of the spatial modes between two sampling events in PDOs. With this lumped model, it is established that under some circumstances PDO bitstreams related to only one of the resonances can be obtained, and that in the antioscillation regions of the PDO the mechanical energy is absorbed into the electrical domain on average. The possibility of selecting for a given resonant frequency the oscillation and antioscillation behaviour allows one to obtain oscillations at any given resonant mode of the MEMS structure.
      366Scopus© Citations 15