Rouzbeh Amini

Proceedings of the 13th Mediterranean Conference on Control and Automation

An equivalent circuit method describing the free stator of piezoelectric motor is presented in this paper, while the circuit elements have complex values. The mechanical, dielectric and piezoelectric losses associated with the vibrator are accounted for by the imaginary components of the circuit elements. It is shown that the calculation of the circuit parameters from the complex elastic, dielectric and piezoelectric material constants is straightforward and the model accuracy is verified with simulation around the important frequencies suitable for motor controller design purposes

Systematic Modeling for Free Stators of Rotary Piezoelectric Ultrasonic Motors

This paper presents an equivalent circuit model with complex numbers that describes the free stator model of traveling-wave ultrasonic motors. The mechanical, dielectric, and piezoelectric losses associated with the vibrator are considered by introducing the imaginary part to the equivalent circuit elements. The determination of the complex circuit elements is performed by using a new, simple iterative method. The presented method uses information about five points of the stator admittance measurements. The accuracy of the model in fitting to the experimental data is verified by using the measurements of a recently developed piezoelectric motor and a well-known USR60

Model-based fault detection for the DELFI-N3XT Attitude Determination System

The Delfi-n3Xt nanosatellite is the second Dutch university satellite currently being developed at the Delft University of Technology. In its design, the Attitude Determination System (ADS) will be pivotal for optimal power point tracking to adequately provide the energy needed for normal operation and charging of the batteries. In this paper we explore a fault detection mechanism for the ADS based on the Unscented Kalman Filter (UKF) state estimator which has been successfully integrated into the simulation and modelling environment. The UKF provides a more computationally efficient estimator than traditional Kalman Filter variants. Faults introduced in the system include changes in the noise model and stuck-at-0 faults, resulting in disturbances in the output of the filter. Parameters of the filter are varied and the behaviour of the outcoming residuals is analyzed to evaluate its effectiveness in the detection of these errors.

Smart Power Management for an Onboard Wireless Sensors and Actuators Network

The employment of wireless links for spacecraft onboard data communication is a new and challenging research topic. This new technology can be conveniently used for attitude determination and control sensors and actuators. Still, providing energy efficient data collection is of paramount importance to such an onboard wireless sensors and actuators network (OWSAN). This paper proposes a power management scheme based on estimation of the sensor measurements with a Kalman Filter. The power manager schedules the sleep periods on the node to lower the energy consumption of the wireless transmitter and the sensor. The simulation results show that there is a significant change in the energy consumption level of an onboard ADCS sensor.

Study of Noise Canceling Performance of Feedforward Fuzzy-Based ANC System under Non-Causal Condition

Feed-forward active noise control (ANC) systems act as adaptive systems to control and cancel undesired signals and noises. If the delay in the noise canceling subsystems increases more than the delays in the primary path, non-causal condition will occur in these systems. In this paper, study of noise canceling performance of feed-forward fuzzy-based ANC systems for ducts under non-causal condition is presented. For this purpose, we use fuzzy filtered-x algorithm as an adaptive filter and the results are compared with classical filtered-x algorithm which is employed under the same conditions. Analysis shows that ANC system using fuzzy algorithm has better efficiency for noise cancellation in non-causal condition

Free Stator Modeling of a Traveling Wave Ultrasonic Motor

An equivalent circuit method describing the free stator of piezoelectric motor is presented in this paper, while the circuit elements have complex values. The mechanical, dielectric and piezoelectric losses associated with the vibrator are accounted for by the imaginary components of the circuit elements. It is shown that the calculation of the circuit parameters from the complex elastic, dielectric and piezoelectric material constants is straightforward and the model accuracy is verified with simulation around the important frequencies suitable for motor controller design purposes

A new scheme for experimental-based modeling of a traveling wave ultrasonic motor

In this paper, a new method for equivalent circuit modeling of a traveling wave ultrasonic motor is presented. The free stator of the motor is modeled by an equivalent circuit containing complex circuit elements. A systematic approach for identifying the elements of the equivalent circuit is suggested which uses the admittance measurement of the free stator. Levenberg-Marquardt parameter estimation algorithm is used to model the alteration of the admittance after placing the rotor on the stator. Thereafter, theoretical assessments and experimental measurements are used to account for the speed reduction arising by placing the rotor on the stator and applying the load torque. Finally, the effects of temperature changes and the resultant response of the motor are computed. Results of the experiments and measurements are used to verify and validate the precision of the new modeling method. I. INTRODUCTION Several researches attempts have been reported on the equivalent circuit modeling of traveling wave ultrasonic motor. The first at- tempt was performed by Sashida in (1). Sashida suggested a model compounded of resistors and diodes which is rather difficult for practical usage. This method and its abridged successors have been the foundation of many later researches in the field of modeling and controller design for ultrasonic motors. This brief paper focuses on a new equivalent circuit modeling method for traveling wave ultrasonic motors. II. MODEL OF FREE STATOR The stator ring can be considered as an infinite length straight beam (1). The admittance of this resonator beam with the electric field perpendicular to its length is given by (2) Y = jωCd + jωCd k 2 31 1 − k 2 31