bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sensorless Positioning Control for Two-Link Robot Arm by Means of Adaptive Identification and Sliding Mode Control
Authors: Ito Takayuki , Nonami Kenzo , Naruke Alberto S. , Fujimoto Takuma 
Published: February 2021

Abstract
In this study, we propose the sensorless positioning control of a two-link robot arm. In order to realize a good sensorless control, we propose to use the parameter adaptive identifier to system with the uncertainties of the coil in the actuator. Also, we use sliding mode control theory to remove the terms of the nonlinear parameters generated by the links mechanism, the nonlinear friction in the gear trains in the joints and the parameter variations caused by handle loads. The proposed control strategy has a good robust performance against these uncertainties. As these results, we have verified the effectiveness of sensorless positioning control by simulations and experiments.
Sound Radiation Sensor: A Neural Net Approach
Authors: Preumont André , François Arnaud , Dubru Sylvie 
Published: February 2021

Abstract
This paper proposes a noise radiation sensor consisting of an array of independent PVDF patches connected to an artificial neural net. The neural net is trained to reconstruct the volume displacement (or velocity) with either numerical or experimental data. A numerical study is conducted, to analyse the influence of the size of the PVDF array on the reconstructed volume velocity.
Integrated Structure-Control Design of a Three-Axis Milling Machine
Authors: De Fonseca P. , Van Brussel H. , Sas P. , Swevers J. 
Published: February 2021

Abstract
The paper discusses the development of an integrated simulation model of the mechanical structure and the control system of a three-axis milling machine for the super-finishing of moulds and dies. This integration encompasses the automatic reduction of a detailed finite element model of the machine tool into a low-order state-space model, appropriate for control system design. It is shown that a multi-stage component mode reduction and synthesis procedure allows a cheap analysis of the machine tool in different spatial configurations. The subsequent development of the motion and vibration control system fully exploits the knowledge of the dynamic behaviour of the machine for all possible tool positions, by a judicious selection of robustness weighting functions in an H∞ control theory framework. The idea of integrating the model of the mechanical structure and of the control system for a simultaneous optimisation of the machine tool performance is essential in the mechatronic design approach.
Adaptive Decentralized Vibration Control of a Cable-Stayed Bridge in the Presence of Seismic Excitation
Authors: Luo Ningsu , Rodellar Jose , De la Sen Manuel , Vehi Josep 
Published: February 2021

Abstract
In this paper, an adaptive decentralized controller is presented to attenuate the transversal vibration of a flexible cable-stayed bridge induced by seismic excitation, in which only local sensor information has been used to generate the control signal that is sent to the actuator. The dynamic behavior of the beam structure is characterized by a nonlinear mathematical model with interconnection terms, which was obtained by using technique of finite element. The controller design is made based on the principle of sliding mode such that a priori knowledge on the exact value of system parameters, structural disturbances and the seismic excitation is not required. In particular, it is assumed that the upper and lower bounds for the seismic excitation are also unknown. The closed-loop robust stability has been achieved through the generation of a sliding motion in the system. Numerical simulation is done to illustrate the effectiveness of the proposed control scheme for a scaled model of the bridge subject to the Taft earthquake.
An Approach to Reliability Analysis Using the Response Surface Method and Monte Carlo Simulation
Authors: Kaymaz Irfan , McMahon Chris A. 
Published: February 2021

Abstract
It is important in reliability evaluation to take an approach in which the required calculations can be performed efficiently in terms of time and cost. In this study, an approach is proposed whereby reliability analysis is carried out by means of Monte Carlo simulation in which the actual performance function is replaced by a function obtained using the response surface method (RSM). The common approach in the conventional RSM is to use a second-degree polynomial for the response surface function, but in many reliability problems this may not be the best choice. This paper first reviews the approaches and limitations of reliability methods, and then goes on to discuss a method of modelling error when using the response surface method for reliability analysis. It shows the errors obtained for different response functions under different circumstances, and then describes the application of a network-based analysis system to reliability problems.
Estimation of Power Density in VLSI Circuits Using Monte Carlo Simulation
Authors: Valenti Mario , Delalic Z. J. , Jahanian S. 
Published: February 2021

Abstract
CMOS technology in the past twenty years has followed the path of device scaling for achieving density, speed, and power improvements. The advancement of lithographic techniques propelled the scaling also of the fine lines to 1 urn width and below. Since the integration density on chip level is constantly increasing there is need to study power dissipation and resulting heat propagation between circuit components. This research studies different methods to analyze the power dissipations and temperature distributions of a full CMOS adder. Through examining many methods, STEPS method was selected for determination of the power dissipation in a VLSI CMOS chip. An experiment was developed for the dynamic power dissipation since static power dissipation is negligible in case of CMOS devices. Using this method one can look at each circuit node individually as signals are propagated through the chip and determine power distribution in the form of heat. Therefore, it is possible to construct a 3-dimensional diagram of the actual distribution of the heat across the chip.
Removal of Cadmium From Contaminated Water
Authors: Jahanian Shariar , Rostami Hossein 
Published: February 2021

Abstract
Over the past 15 years, about one half million sites with potential contamination have been reported to federal or state authorities. Of these, about 217,000 sites still need remediation (1) and new contaminated sites continue to appear each year. The most common type of contaminants are metals, solvents and petroleum products. Heavy metals are present in two thirds of DOD and superfund sites and about 50% of DOE and RCRA sites.
AAM is a new material that possesses the ability to remove heavy metal from conaminated water. AAM consists of fly ash activating chemicals and fillers. AAM barrier material was used to remove Cd from contamination water. Fly ash from three different sources were used to produce reactive barrier of different permeability. AAM materials with permeability 10−2 to 10−1 was created. Only highest permeability proved to be viable for reactive barrier material. AAM barrier from three ash sources with permeability of 10−1 was produced and crushed into pelletized form. To determine effectiveness of the various barriers batch test was performed, based on that result the column test was conducted.
In this work contamination barrier with controled permeabilty was tested to determine its ability to remove Cd from contaminated water. AAM barrier material was used in column test to remove Cd from 1000 ppm and 10 ppm solution. The results show that AAM barrier is very effective in removing Cd from highly contaminated water (up 99% efficiency).
Possible Advantage of Nonlinear Over Linear Analyses for Design
Authors: Liu Longjun 
Published: February 2021

Abstract
Many metal stress-strain curves show “tiny” difference between linear approximation and real curves around yield strength. But actually it can be very large. It could produce smaller or much smaller stress when the real curves are applied in nonlinear stress analysis, comparing to linear one. The output difference is larger when product (e.g. plate) deflection is comparable to its thickness or bigger. The theoretical curves based on minimum guaranteed strength and elongation seem to be able to provide conservative design for both stress and deflection control, if they can accurately represent the real curves. Application of nonlinear analysis might have significant impact on product competitiveness. A lot more research is needed beyond this introductory report, including physical tests, to further explore the possibility and develop the methodology if possible, before any actual application for real product design can be started.
Vehicle Lifts: The Hyperstatic Problem
Authors: Barnett Ralph L. , Poczynok Peter J. 
Published: February 2021

Abstract
Occasionally, vehicles topple off of structurally sound automobile lifts, even when they are properly supported at their lift points. This happens with a family of lifts that use four arms to position lifting pads under the vehicle chassis. The arms operate in a horizontal plane and are positioned by swinging and telescoping. Gravity loading of the pads and the attendant horizontal friction resistance cannot be relied upon to maintain the set-up position of the pads. There is a non-obvious structural phenomena called hyperstatic behavior that may easily lead to minimal, or even zero, pad loading with the attendant loss of resistance to horizontal pad movement. Unless otherwise restrained, the bumping and jostling associated with vehicle maintenance can produce random forces that will push a pad from beneath the vehicle. The resulting three-point support almost always leads to toppling of the vehicle from the lift.
Analytical Investigation of Strongly Nonlinear Dynamical Systems
Authors: Andrianov Igor V. , Awrejcewicz Jan 
Published: February 2021

Abstract
A new asymptotic approach to the analytical investigation of strongly nonlinear dynamical systems is presented. First, periodic oscillations of the systems governed by homogeneous dynamical equations with a polynomial nonlinearity are considered. Then, a period of strong nonlinear oscillations of the mathematical pendulum is estimated analytically. Finally, a construction of periodic solutions to the partial differential equations with nonlinear boundary conditions is outlined.
Analytical Stability Improvement of the Periodic Vibro-Impact Processes
Authors: Awrejcewicz Jan , Tomczak Krzysztof 
Published: February 2021

Abstract
In this paper an attention is focused on stabilisation improvement of periodic orbits of a one- and two-degree-of-freedom nonautonomous vibro-impact systems. This approach, among others, includes two problems. 1. A possibility of a sufficient stability improvement of the considered vibro-impact periodic motion using a feedback loop control is presented. 2. An original analytical averaging technique applied to a one-degree-of-freedom system is demonstrated. It enables to predict the efficient delay loop coefficients in order to achieve the desired stabilisation. In addition, an efficient delay loop control applied to two-degree-of-freedom system is proposed and illustrated.
A Wavelet Based Procedure to Study Vibrations and Stability
Authors: Pernot S. , Lamarque C. H. 
Published: February 2021

Abstract
A Wavelet-Galerkin procedure is introduced in order to obtain periodic solutions of multidegrees-of-freedom dynamical systems with periodic time-varying coefficients. The procedure is then used to study the vibrations of parametrically excited mechanical systems. As problems of stability analysis of nonlinear systems are often reduced after linearization to problems involving linear differential systems with time-varying coefficients, we demonstrate the method provides efficient practical computations of Floquet exponents and consequently allows to give estimators for stability/instability levels. A few academic examples illustrate the relevance of the method.
Energy Shaping Control of Electrostatic Membrane Vibrations
Authors: Kugi Andreas , Schlacher Kurt , Kaltenbacher Manfred , Lerch Reinhard 
Published: February 2021

Abstract
A strong analytical mathematical formulation of electrostatic transducers is the necessary prerequisite for the design of feedback controllers. Based on the theory of Hamiltonian systems the mathematical model of a typical electrostatic transducer configuration with a moving membrane electrode and a rigid backplate electrode is derived. It is a well known fact that an increase in the sensitivity of the transducer often brings about also an increase in the nonlinear distortion and may occur a sticking of the membrane to the backplate electrode. In this paper, we propose a concept that gives a possible solution for these undesirable effects by using a controlled voltage source for the supply voltage of the transducer. The controller is designed by shaping the potential energy of the closed loop system. The change of the capacity of the transducer due to the motion of the membrane is considered as the sensor output.
Vibration Control of Plates Using Electromagnetic Compressional Damping Treatment
Authors: Omer A. , Baz A. 
Published: February 2021

Abstract
A new class of structural damping treatments is introduced. This class is the Electromagnetic Compressional Damping Treatment (ECDT) which relies in its operation on a viscoelastic damping layer sandwiched between an electromagnet and a permanent magnet. Interaction between the magnets generates magnetic forces that enhance the compressional damping mechanism of the viscoelastic layer. With proper tuning of the magnetic forces, in response to the structural vibration, undesirable resonances and catastrophic failures can be avoided. The fundamentals and the underlying phenomena associated with the ECDT are investigated theoretically and experimentally.
A finite element model is developed to describe the interaction between the dynamics of flexible plates, the visco-elastic damping layer and the electro-magnetic actuators. The validity of the developed finite element model is checked experimentally using aluminum plates treated with single and multi-ECDT patches. The plate/ECDT system is subjected to sinusoidal excitations and its multi-mode response is monitored when the electro-magnetic actuator is activated or not. Several control strategies are considered to activate the electro-magnetic actuator including simple PD controllers. The performance of the uncontrolled and controlled system is determined at various operating conditions. Comparisons with conventional Passive Constrained Layer Damping (PCLD) treatments emphasize the potential of the ECDT treatment as an effective means for controlling structural vibrations.
Active Control of Elastodynamic Vibrations of a Flexible Mechanism With Piezoelectric Actuator
Authors: Chen Ching-I 
Published: February 2021

Abstract
This study focused on the application of active vibration control strategies for flexible moving structures which degrade into transient dynamic vibration problem. These control strategies are based primarily on modal control methods in which the flexible moving structures are controlled by reducing their dominant vibration modes. This work numerically investigated active control of the elastodynamic response of a four-bar mechanical system, using a piezoelectric actuator. A controller based on the modified independent modal space control theory was also utilized. This control theory produced overall excellent performance in terms of achieving the desired closed-loop structural damping. The merits of this technique include its ability to manage the spill-over effect, i.e. eliminate the magnitude of vibrations associated with uncontrolled modes, using only a few selected modes for control. This control was accomplished using a time sharing technique, which reduces the number of piezoelectric actuators required to control a large number of vibration modes. Furthermore, this algorithm implements a procedure for determining the optimal locations for the piezoelectric actuators.
The dynamics of a steel four-bar linkage was selected with a flexible coupler separated by six elements and one piezoelectric actuator was used in the numerical simulation. The optimal actuator position was located at the third element from the right to the left. Results in this study demonstrated that a highly desired the structural vibration damping could be achieved. This control technique can be applied to transient dynamic systems.
Two-Degree-of Freedom Control Using H∞ and ANVC to Reduce the Vibration of Vehicle Engine-Body System
Authors: Ito Ryogo , Yang Jianming , Suematsu Yoshikazu , Shimizu Sohta , Arai Nomio 
Published: February 2021

Abstract
This paper presents a two-degree-of freedom (2DOF) controller, which is combined a feedback (FB) controller with feedforward (FF) controller, to control the vibration of vehicle engine-body system. The robust feedback controller is designed by H∞ theory to attenuate the influence of engine vibration disturbance by modelling the vehicle engine-body system as nominal four-degree-of freedom vibration system with unmodelled disturbance. Based on filtered-X LMS algorithm, an active noise and vibration control is used in a feedforward controller to improve control performance further. To demonstrate the effectiveness of the control scheme, we have made some experiments in an experimental device, which is designed to imitate a real vehicle engine-body system.
A Novel Technique for the Stability of Multiple Frequency Resonators
Authors: Olgac Nejat 
Published: February 2021

Abstract
A novel stability analysis is presented for feedback controlled systems with multiple unrelated time delays. The concern arises in an effort creating multi-frequency delayed resonators. Despite the broad treatment of single time delay cases there is no mechanism to analyze the stability of systems involving multiple delays. The proposed method is an advancement over the D-subdivision methodology. It reduces the stability based subdivisions and search to a single dimensional space instead of multiple dimensional platform. The method is very simple to implement and it results in the stability assessment of the given system as the number of unstable root pairs present.
The Nonlinear Behaviour of a Pantograph Current Collector Suspension
Authors: Drugge L. , Larsson T. , Berghuvud A. , Stensson A. 
Published: February 2021

Abstract
The pantograph-catenary system is a critical component for trains required to run at higher speeds. The pantograph often includes nonlinear characteristics and the scope of this work is to investigate if nonlinear dynamic phenomena can occur in an existing design. A model of a pantograph suspension subsystem has been developed according to physical parameter values of the head suspension of the Schunk WBL88/X2 pantograph, providing electric power to the Swedish high-speed train X2. Studies of the system response for different force excitation show both harmonic, subharmonic and chaotic behaviour for the investigated parameter regions.
Stabilization to Nonlinear Systems With Short Time Delay in State Feedback
Authors: Wang Zaihua , Hu Haiyan 
Published: February 2021

Abstract
Local stabilization lo critically stable nonlinear systems with a short time delay in state feedback is discussed in this paper. The stabilizing procedure is composed of two steps. The first step is to simplify the retarded differential equation to an ordinary differential equation by using a linear transform with memory controller and neglecting some high order terms. Then the system equation is simplified into the standard critical forms of ordinary differential equation, and consequently, the center manifold reduction is applied to stabilizing the simplified systems of critical cases. Both analysis and simulation show that the approach is effective if the time delay is short enough.
Uniformly Bounded Input Gives Ultimately Bounded Output: On the Dynamics of a Piecewise Linear Beam System
Authors: Heertjes Marcel F. , van de Molengraft Marinus J. G. , Kok Jan J. 
Published: February 2021

Abstract
A periodically excited piecewise linear beam system is studied. The beam system consists of a supported multi-degree-of-freedom beam with one-sided spring. This system is proved to have a 1-periodic solution to any uniformly bounded periodic force applied along the beam. The existence of a 1-periodic solution will be shown numerically and experimentally for both a harmonic force and a block-wave force.
Braille Printer Dynamics
Authors: Jerrelind J. , Stensson A. 
Published: February 2021

Abstract
A Braille printer forms dots in paper, which are read by blind people. The dots are produced by hammers, which basically consist of a spring loaded moving core that is excited by electromagnetic forces. The system is characterised by non-linear properties such as electromagnetic forcing and impacts. Problems with quality, high temperature and noise limit the operating speed of the printer. To investigate if printing quality problems are caused by the non-linear dynamics in the system, one existing design is modelled and used for evaluation. The simulations show that some mechanical parameters are critical in order to get satisfactory quality on the Braille text.
Nonlinear Dynamics of Percussive Drilling of Hard Materials
Authors: Krivtsov Anton M. , Wiercigroch Marian 
Published: February 2021

Abstract
It is postulated that the main mechanism of the enhancement of material removal rate (MRR) in percussive drilling is associated with generating impact forces, which act on the work-piece and help to develop micro-cracking in the cutting zone. The inherent non-linearity of the discontinuous impact process is modelled as a frictional pair, to generate the pattern of the impact forces. A novel formula for calculating the MRR is proposed, which explains the experimentally observed fall in MRR at higher static forces.
Fold Bifurcations in Discontinuous Systems
Authors: Leine Remco I. , van Campen Dick H. 
Published: February 2021

Abstract
This paper treats discontinuous fold bifurcations of periodic solutions of discontinuous systems. It is shown how jumps in the fundamental solution matrix lead to jumps of the Floquet multipliers of periodic solutions. A Floquet multiplier of a discontinuous system can jump through the unit circle causing a discontinuous bifurcation. Numerical examples are treated which show discontinuous fold bifurcations. The discontinuous fold bifurcation can connect stable branches to branches with infinitely unstable solutions.
Near-Grazing Behaviour of the Harmonic Ocsillator
Authors: Molenaar J. , de Weger J. G. , v. d. Water W. 
Published: February 2021

Abstract
Impacting systems are intrinsically nonlinear. They are found in a great variety of mechanical constructions. The control of the impact phenomena requires a thorough understanding of the dynamics involved. It is discussed that near-grazing systems, i.e. systems in which the impacts take place at low speed, can be described by discrete mappings. The form of this mapping for a harmonic oscillator with a stop is dealt with in detail. It is pointed out how these mappings can be derived and the results are compared to results earlier published. It is indicated how the present results could be checked experimentally.