Structural Modeling and Dynamic Analysis of a Piezoelectric Forceps Actuator

Author(s):  
Ken Susanto ◽  
Bingen Yang

A piezoelectric forceps actuator (PFA) is recently invented for potential use in minimum invasive and non-invasive surgery and diagnosis, and other biomedical applications. This paper is concerned with structural modeling, dynamic analysis, and feedback control of such an actuator. The PFA is modeled as a composite curved beam with laminated piezoelectric layers. The exact open-loop and closed-loop transfer functions of the PFA control system consisting of the curved beam, sensor, actuator and control logic are obtained in exact and closed form without discretization. With the transfer function formulation, the natural frequencies and frequency response of the actuator are then predicted and a simple feedback control law is implemented. The theoretical model of the actuator is validated in experiments.

1985 ◽  
Vol 107 (3) ◽  
pp. 200-206 ◽  
Author(s):  
Y. Sakawa ◽  
A. Nakazumi

In this paper we first derive a dynamical model for the control of a rotary crane, which makes three kinds of motion (rotation, load hoisting, and boom hoisting) simultaneously. The goal is to transfer a load to a desired place in such a way that at the end of transfer the swing of the load decays as quickly as possible. We first apply an open-loop control input to the system such that the state of the system can be transferred to a neighborhood of the equilibrium state. Then we apply a feedback control signal so that the state of the system approaches the equilibrium state as quickly as possible. The results of computer simulation prove that the open-loop plus feedback control scheme works well.


Author(s):  
V. P. Belavkin

A brief account of the quantum information dynamics and dynamical programming methods for optimal control of quantum unstable systems is given to both open loop and feedback control schemes corresponding respectively to deterministic and stochastic semi-Markov dynamics of stable or unstable systems. For the quantum feedback control scheme, we exploit the separation theorem of filtering and control aspects as in the usual case of quantum stable systems with non-demolition observation. This allows us to start with the Belavkin quantum filtering equation generalized to demolition observations and derive the generalized Hamilton–Jacobi–Bellman equation using standard arguments of classical control theory. This is equivalent to a Hamilton–Jacobi equation with an extra linear dissipative term if the control is restricted to Hamiltonian terms in the filtering equation. An unstable controlled qubit is considered as an example throughout the development of the formalism. Finally, we discuss optimum observation strategies to obtain a pure quantum qubit state from a mixed one.


Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 421
Author(s):  
Min-Jae Seo

This work presents a 12 bit 200 MS/s dual-residue pipelined successive approximation registers (SAR) analog-to-digital converter (ADC) with a single open-loop residue amplifier (RA). By using the inherent characteristics of the SAR conversion scheme, the proposed ADC sequentially generates two residue levels from the single RA, which eliminates the need for inter-stage gain-matching calibration. To convert the sequentially generated the two residues, a capacitive interpolating SAR ADC (I-SAR ADC) is also proposed. The I-SAR ADC is very compact because it consists of the one comparator, a CDAC, and control logic like a conventional SAR ADC. In addition, the I-SAR ADC needs no static power dissipation for the residue interpolation. A prototype ADC fabricated in a 40 nm CMOS technology occupies an active area of 0.026 mm2. At a 200 MS/s sampling-rate with the Nyquist input, the ADC achieves an SNDR (Signal-to-Noise distortion ratio) of 62.1 dB and 67.1 dB SFDR (Spurious-Free Dynamic Range), respectively. The total power consumed is 3.9 mW under a 0.9 V supply. Without any inter-stage mismatch calibration, the ADC achieve Walden Figure-of-Merit (FoM) of 19.0 fJ/conversion-step.


1990 ◽  
Vol 112 (3) ◽  
pp. 337-348 ◽  
Author(s):  
M. J. Grimble

A H∞ optimal control problem is considered which leads to a particularly simple controller structure. The expression for the optimal controller only requires the solution of one diophantine equation which makes it very appropriate for self-tuning control applications. The controller developed is related to the Observations Weighted control law which involves the minimization of tracking error and control signal variances. The H∞ criterion minimized may be expressed in a signal spectrum minimization form or in a sensitivity minimization form. The system can be guaranteed to be stable under low control weighting (high gain) conditions even for non-minimum phase open-loop unstable plants. The design of the controller depends upon the specification of the cost weighting transfer-functions and this is illustrated in a design example.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Katarzyna Sołkiewicz ◽  
Hubert Krotkiewski ◽  
Marcin Jędryka ◽  
Ewa M. Kratz

AbstractEndometriosis is an inflammatory disease which diagnostics is difficult and often invasive, therefore non-invasive diagnostics methods and parameters are needed for endometriosis detection. The aim of our study was to analyse the glycosylation of native serum IgG and IgG isolated from sera of women classified as: with endometriosis, without endometriosis but with some benign ginecological disease, and control group of healthy women, in context of its utility for differentiation of advanced endometriosis from the group of healthy women. IgG sialylation and galactosylation/agalactosylation degree was determined using specific lectins: MAA and SNA detecting sialic acid α2,3- and α2,6-linked, respectively, RCA-I and GSL-II specific to terminal Gal and terminal GlcNAc, respectively. The results of ROC and cluster analysis showed that the serum IgG MAA-reactivity, sialylation and agalactosylation factor may be used as supplementary parameters for endometriosis diagnostics and could be taken into account as a useful clinical tool to elucidate women with high risk of endometriosis development. Additionally, we have shown that the analysis of native serum IgG glycosylation, without the prior time-consuming and expensive isolation of the protein, is sufficient to differentiation endometriosis from a group of healthy women.


Sign in / Sign up

Export Citation Format

Share Document