scholarly journals Continuous Modeling of a Multi-Link Flexible Transmission

2008 ◽  
Vol 15 (2) ◽  
pp. 163-177 ◽  
Author(s):  
Irit Peled ◽  
Yoram Halevi
Keyword(s):  
Transfer Functions ◽  
Building Blocks ◽  
Simulation Software ◽  
Infinite Dimension ◽  
Physical Insight ◽  
Single Input ◽  
Continuous Modeling ◽  
Rational Expressions ◽  
Generalized State ◽  
Function Matrix

The problem of dynamic, infinite dimension, modeling of a transmission is considered. An accurate Laplace transfer function matrix of the system that consists of flexible shafts connected by gears that are either rigid or flexible is found. The first step is deriving a set of single input, infinite dimension, transfer functions for a single uniform link. The building blocks of those transfer functions are time delays, representing the wave motion, and low order rational expressions, representing the boundary phenomena. The next step is combining these individual transfer functions into an overall model of the transmission, by means of the link reaction approach that makes use of the geometric relationships and reaction moments between neighboring links. The outcome is a generalized dynamic model with the moments in the gear pairs as the generalized state vector. The explicit and highly structured form of the transfer functions allows physical insight into the system, exact calculation of natural frequencies and the construction of exact simulation schemes built from standard blocks that are available in multi-purpose simulation software.

Transfer Function Modeling of a Flexible Gear Train

2006 ◽  
Author(s):  
Irit Peled ◽  
Yoram Halevi
Keyword(s):  
Transfer Function ◽  
Transfer Functions ◽  
Dynamical Behavior ◽  
Building Blocks ◽  
Gear Train ◽  
Infinite Dimension ◽  
Control Laws ◽  
Physical Insight ◽  
Single Input ◽  
Rational Expressions

The problem of dynamic, infinite dimension, modeling of a gear train is considered. It includes derivation of the accurate, Laplace transfer function matrix of the system that consists of flexible shafts, individually governed by the wave equation, connected by gears that are either rigid or flexible. The first step is deriving a set of single input, infinite dimension, transfer functions for a single uniform link. The building blocks of those transfer functions are time delays, representing the wave motion, and low order rational expressions, representing the boundary phenomena. The next step is constructing a model for the multi-link gear train system, by using the natural feedback within the system to arrive at a generalized dynamic model. This explicit and highly structured form of transfer functions, allows physical insight into the system, which is lacking in finite dimension approximations. It was used for the analysis of the dynamical behavior of the gear train and may also be used for the design of dedicated control laws.

Error analyses of a Multi-Input-Multi-Output cantilever beam test

2021 ◽  
pp. 107754632110337
Author(s):  
Arup Maji ◽  
Fernando Moreu ◽  
James Woodall ◽  
Maimuna Hossain
Keyword(s):  
Transfer Function ◽  
Frequency Domain ◽  
Cantilever Beam ◽  
Transfer Functions ◽  
Linear Superposition ◽  
Transfer Function Matrix ◽  
Error Analyses ◽  
Pseudo Inverse ◽  
Function Matrix

Multi-Input-Multi-Output vibration testing typically requires the determination of inputs to achieve desired response at multiple locations. First, the responses due to each input are quantified in terms of complex transfer functions in the frequency domain. In this study, two Inputs and five Responses were used leading to a 5 × 2 transfer function matrix. Inputs corresponding to the desired Responses are then computed by inversion of the rectangular matrix using Pseudo-Inverse techniques that involve least-squared solutions. It is important to understand and quantify the various sources of errors in this process toward improved implementation of Multi-Input-Multi-Output testing. In this article, tests on a cantilever beam with two actuators (input controlled smart shakers) were used as Inputs while acceleration Responses were measured at five locations including the two input locations. Variation among tests was quantified including its impact on transfer functions across the relevant frequency domain. Accuracy of linear superposition of the influence of two actuators was quantified to investigate the influence of relative phase information. Finally, the accuracy of the Multi-Input-Multi-Output inversion process was investigated while varying the number of Responses from 2 (square transfer function matrix) to 5 (full-rectangular transfer function matrix). Results were examined in the context of the resonances and anti-resonances of the system as well as the ability of the actuators to provide actuation energy across the domain. Improved understanding of the sources of uncertainty from this study can be used for more complex Multi-Input-Multi-Output experiments.

Modes of nonlinear couplers: building blocks for physical insight

1989 ◽  
Vol 14 (20) ◽  
pp. 1143 ◽  
Author(s):  
D. John Mitchell ◽  
Allan W. Snyder
Keyword(s):  
Building Blocks ◽  
Physical Insight

Image Reconstruction Algorithm Based On PCA and WNN for ECT

2013 ◽  
Vol 5 (4) ◽  
pp. 33-40
Author(s):  
Lifeng Zhang
Keyword(s):  
Image Reconstruction ◽  
Adaptive Learning ◽  
Transfer Functions ◽  
Measurement Data ◽  
Principal Component ◽  
Reconstruction Algorithm ◽  
Simulation Software ◽  
Iteration Algorithm ◽  
Two Phase ◽  
Image Reconstruction Algorithm

Electrical capacitance tomography (ECT) technique is a new technique for two-phase flow measurement. ECT is a complex nonlinear problem. To solve the ill-posed image reconstruction problem, image reconstruction algorithm based on wavelet neural networks (WNN) was presented. The principal component analysis (PCA) method was used to reduce the dimension of the input vectors. The transfer functions of the neurons in the WNN were wavelet base functions which were determined by retract and translation factors. The input measurement data were obtained using the ECT simulation software developed by the author. BP algorithm was used to train the WNN, and self-adaptive learning rate and momentum coefficient were also used to accelerate the learning speed. Experimental results showed the image quality has been improved markedly, compared with the typical linear back projection (LBP) algorithm and Landweber iteration algorithm.

Voltage Differencing Gain Amplifier-Based nth-Order Low-Pass Voltage-Mode Filter

2018 ◽  
Vol 27 (06) ◽  
pp. 1850089 ◽  
Author(s):  
Zehra Gulru Cam Taskiran ◽  
Herman Sedef ◽  
Fuat Anday
Keyword(s):  
General Formula ◽  
Building Block ◽  
Transfer Functions ◽  
Building Blocks ◽  
Voltage Mode ◽  
Active Elements ◽  
Filter Structure ◽  
Low Pass ◽  
Minimum Number ◽  
Simple Filter

In this paper, a new active-C filter realizing the general [Formula: see text]th-order low-pass voltage transfer functions using [Formula: see text] voltage differencing gain amplifiers (VDGAs) is presented. In this realization minimum number of equal-valued grounded capacitors and [Formula: see text] active elements are used. Due to the adjustability of the transconductance of the VDGA with current, different gains can be realized using the same building block and a simple filter structure can be created. The filter which is composed of VDGA building blocks is suitable for integration and advantageous in terms of eliminating parasitic effects because all capacitors are grounded and the filter structure has no resistors. All simulations are performed on SPICE and the accuracy of this method is validated experimentally with commercially available products upon on-board circuit.

Off-Road Vehicle Dynamics Mobility Simulation With a Compaction Based Deformable Terrain Model

2013 ◽  
Author(s):  
Justin Madsen ◽  
Andrew Seidl ◽  
Dan Negrut
Keyword(s):  
Vehicle Dynamics ◽  
Transfer Functions ◽  
Soil Mechanics ◽  
Three Dimensional ◽  
Interaction Model ◽  
Simulation Software ◽  
Repeated Loading ◽  
Model Parameters ◽  
Vehicle Simulation ◽  
Terrain Model

This paper discusses the terramechanics models developed to incorporate a physics-based, three dimensional deformable terrain database model with vehicle dynamics mobility simulation software. The vehicle model is contained in Chrono, a research-grade C++ based Application Programming Interface (API) that enables accurate multibody simulations. The terrain database is also contained in a C++ based API, and includes a general tire-terrain interaction model which is modular to allow for any tire model that supports the Standard Tire Interface (STI) to operate on the terrain. Furthermore, the ability to handle arbitrary, three dimensional traction element geometry allows for tracked vehicles (or vehicle hulls) to also interact with the deformable terrain. The governing equations of the terrain are based on a soil compaction model that includes both the propagation of subsoil stresses due to vehicular loads, and the resulting visco-elastic-plastic stress/strain on the affected soil volume. Non-flat, non-homogenous and non-uniform soil densities, rutting, repeated loading and strain hardening effects are all captured in the vehicle mobility response as a result of the general 3-D tire/terrain model developed. Pedo-transfer functions allow for the calculation of the soil mechanics model parameters from existing soil measurements. This terrain model runs at near real-time speed, due to parallel CPU and GPU implementation. Results that exercise the force models developed with the 3-D tire geometry are presented and discussed for a kinematically driven tire and a full vehicle simulation.

Decomposition Strategies for the Synthesis of Single Input-Single Output and Dual Input-Single Output Compliant Mechanisms

2007 ◽  
Author(s):  
Charles Kim
Keyword(s):  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Single Point ◽  
Building Blocks ◽  
New Method ◽  
Single Input Single Output ◽  
Single Output ◽  
Alternative Method ◽  
Decomposition Strategies ◽  
Single Input

In this paper a new method for the synthesis of compliant mechanism topologies is presented which involves the decomposition of motion requirements into more easily solved sub-problems. The decomposition strategies are presented and demonstrated for both single input-single output (SISO) and dual input-single output (DISO) planar compliant mechanisms. The methodology makes use of the single point synthesis (SPS) which effectively generates topologies which satisfy motion requirements at one point by assembling compliant building blocks. The SPS utilizes compliance and stiffness ellipsoids to characterize building blocks and to combine them in an intelligent manner. Both the SISO and DISO problems are decomposed into sub-problems which may be addressed by the SPS. The decomposition strategies are demonstrated with illustrative example problems. This paper presents an alternative method for the synthesis of compliant mechanisms which augments designer insight.

scholarly journals A New Low-Voltage Low-Power Dual-Mode VCII-Based SIMO Universal Filter

Electronics ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 765 ◽  
Author(s):  
Leila Safari ◽  
Gianluca Barile ◽  
Giuseppe Ferri ◽  
Vincenzo Stornelli
Keyword(s):  
Low Power ◽  
Transfer Functions ◽  
Low Voltage ◽  
Supply Voltage ◽  
Building Blocks ◽  
Cmos Technology ◽  
Universal Filter ◽  
Dual Mode ◽  
Input Multiple Output ◽  
Low Pass

In this paper, a new low-voltage low-power dual-mode universal filter is presented. The proposed circuit is implemented using inverting current buffer (I-CB) and second-generation voltage conveyors (VCIIs) as active building blocks and five resistors and three capacitors as passive elements. The circuit is in single-input multiple-output (SIMO) structure and can produce second-order high-pass (HP), band-pass (BP), low-pass (LP), all-pass (AP), and band-stop (BS) transfer functions. The outputs are available as voltage signals at low impedance Z ports of the VCII. The HP, BP, AP, and BS outputs are also produced in the form of current signals at high impedance X ports of the VCIIs. In addition, the AP and BS outputs are also available in inverting type. The proposed circuit enjoys a dual-mode operation and, based on the application, the input signal can be either current or voltage. It is worth mentioning that the proposed filter does not require any component matching constraint and all sensitivities are low, moreover it can be easily cascadable. The simulation results using 0.18 μm CMOS technology parameters at a supply voltage of ±0.9 V are provided to support the presented theory.

scholarly journals Electronic and Magnetic Properties of Building Blocks of Mn and Fe Atomic Chains on Nb(110)

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1933
Author(s):  
András Lászlóffy ◽  
Krisztián Palotás ◽  
Levente Rózsa ◽  
László Szunyogh
Keyword(s):  
Ground State ◽  
Nearest Neighbor ◽  
Local Density ◽  
Building Blocks ◽  
Orbital Decomposition ◽  
Atomic Chains ◽  
Physical Insight ◽  
The Difference ◽  
Atomic Coordination ◽  
Spin Spiral

We present results for the electronic and magnetic structure of Mn and Fe clusters on Nb(110) surface, focusing on building blocks of atomic chains as possible realizations of topological superconductivity. The magnetic ground states of the atomic dimers and most of the monatomic chains are determined by the nearest-neighbor isotropic interaction. To gain physical insight, the dependence on the crystallographic direction as well as on the atomic coordination number is analyzed via an orbital decomposition of this isotropic interaction based on the spin-cluster expansion and the difference in the local density of states between ferromagnetic and antiferromagnetic configurations. A spin-spiral ground state is obtained for Fe chains along the [11¯0] direction as a consequence of the frustration of the isotropic interactions. Here, a flat spin-spiral dispersion relation is identified, which can stabilize spin spirals with various wave vectors together with the magnetic anisotropy. This may lead to the observation of spin spirals of different wave vectors and chiralities in longer chains instead of a unique ground state.

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