scholarly journals Motion of mechanical systems with non-ideal constraints

2013 ◽  
Vol 35 (2) ◽  
pp. 157-167
Author(s):  
Do Sanh ◽  
Dinh Van Phong ◽  
Do Dang Khoa
Keyword(s):  
Theoretical Analysis ◽  
Mechanical System ◽  
Mechanical Systems ◽  
New Method ◽  
Physical Parameters ◽  
Interactive Environment ◽  
Reaction Forces

In the paper a new method to consider a mechanical system with non-ideal constraints is presented. It is proved that a mechanical system subjected to physical non-ideal constraints cannot be determined purely by theoretical analysis because the reaction forces depend on the physical parameters of interactive environment, which are defined only by measurement. The Principle of Compatibility is shown to be an effective tool in combination with experience for investigating such a problem. For illustration the dynamics of a digging machine are investigated.

CONTINUOUS TUNING OF SHIP PROPULSION SYSTEM BY MEANS OF PNEUMATIC TUNER OF TORSIONAL OSCILLATION

2021 ◽  
Vol 158 (A3) ◽  
Author(s):  
J Homišin ◽  
P Kaššay ◽  
M Puškár ◽  
R Grega ◽  
J Krajňák ◽  
...  
Keyword(s):  
Mechanical System ◽  
Dynamic Properties ◽  
Torsional Oscillation ◽  
Self Regulation ◽  
Mechanical Systems ◽  
New Method ◽  
Driving Mechanism ◽  
Optimal Tuning ◽  
Continuous Tuning ◽  
The Given

Mechanical system drives consist of driving machines and gearing mechanisms interconnected by shafts and couplings. In terms of dynamics it is possible to say that every driving mechanism is able to oscillate. Especially piston devices can create excessive torsional oscillation, vibrations, as well as noise. Important task of a designer is to reduce torsional oscillation in mechanical systems. Presently this problem is mainly solved by the flexible shaft couplings that are selected with regard to the dynamic properties of the given system. It means that every torsional oscillating mechanical system needs to be suitably tuned. The aim of this paper is to present the possibilities of controlling of dangerous torsional oscillations of the mechanical systems by the means of new method, i.e. its optimal tuning by means of the pneumatic coupling with self-regulation, which were developed by us.

The Control of Vibration Transmissibility Using an Electrodynamic Actuator –Close-Loop Solution

2013 ◽  
Vol 436 ◽  
pp. 166-173
Author(s):  
A. Mihaela Mîţiu ◽  
Daniel Constantin Comeagă ◽  
Octavian G. Donţu
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Mechanical System ◽  
Closed Loop ◽  
Mechanical Systems ◽  
Vibration Transmissibility ◽  
Technical Solutions ◽  
The Mathematical Model

In this paper are presented some aspects of transmissibility control of mechanical systems with 1 DOF so that the effects of vibration on their action to be minimized. Some technical solutions that can be used for this purpose is analyzed. Starting from the mathematical model of an electro-mechanical system with 1 DOF, are identified the parameters which influence the effectiveness of the transmissibility control system using an electrodynamic actuator who work in "closed loop".

Controlled Arming of Mechanical Systems Embedded into Embarked Electrical Systems

2014 ◽  
Vol 555 ◽  
pp. 209-216
Author(s):  
Gheorghe Negru
Keyword(s):  
Kalman Filter ◽  
Mechanical System ◽  
High Speed ◽  
Mechanical Systems ◽  
Electrical Systems ◽  
General Motion

The paper presents an application of the Kalman filter to achieve the controlled arming of mechanical system embedded into embarked electrical systems (FMES). The solution of FMES which contain mechanical subsystems electronically controlled could significantly reduce the influence, on their functioning, of the general motion of high speed object (HSO) .

The Method for Determining the Vibration-Damping Elements for the Mechanical System to Obtain the Desired Amplitude Value

2014 ◽  
Vol 657 ◽  
pp. 644-648 ◽  
Author(s):  
Andrzej Dymarek ◽  
Tomasz Dzitkowski
Keyword(s):  
Mechanical System ◽  
Dynamic Characteristics ◽  
Vibration Reduction ◽  
Mechanical Systems ◽  
Vibration Damping ◽  
Displacement Velocity ◽  
Synthesis Methods ◽  
Resonance Frequencies

The paper presents the use of synthesis methods to determine the parameters of passive vibration reduction in mechanical systems. Passive vibration reduction in a system is enabled by units called dampers whose values are determined on the basis of the method formulated and formalized by the authors. The essence of the method are, established at the beginning of a task, dynamic characteristics in the form of the resonance and anti-resonance frequencies, and amplitudes of displacement, velocity or acceleration of vibration.

A Method for Identifying Parameters of Mechanical Joints

1990 ◽  
Vol 57 (2) ◽  
pp. 337-342 ◽  
Author(s):  
J. Wang ◽  
P. Sas
Keyword(s):  
Physical Parameter ◽  
Mechanical Systems ◽  
Degree Of Freedom ◽  
Modal Testing ◽  
Physical Parameters ◽  
Mechanical Joints ◽  
Joint Parameters

A method for identifying the physical parameters of joints in mechanical systems is presented. In the method, a multi-d.o.f. (degree-of-freedom) system is transformed into several single d.o.f. systems using selected eigenvectors. With the result from modal testing, each single d.o.f. system is used to solve for a pair of unknown physical parameters. For complicated cases where the exact eigenvector cannot be obtained, it will be proven that a particular physical parameter has a stationary value in the neighborhood of an eigenvector. Therefore, a good approximation for a joint physical parameter can be obtained by using an approximate eigenvector and the exact value for the joint parameters can be reached by carrying out this process in an iterative way.

SINS Installation Error Calibration Based on Multi-Position Combinations

2011 ◽  
Vol 383-390 ◽  
pp. 4213-4220
Author(s):  
Zhen Huan Wang ◽  
Xi Jun Chen ◽  
Qing Shuang Zeng
Keyword(s):  
Theoretical Analysis ◽  
Least Squares ◽  
Rotation Rate ◽  
Scale Factor ◽  
New Method ◽  
Earth’S Rotation ◽  
Earth's Rotation ◽  
Error Calibration ◽  
Sine And Cosine Functions ◽  
Cosine Functions

A new method is proposed to calibrate the installation errors of SINS. According to the method, the installation errors of the gyro and accelerometer can be calibrated simultaneously, which not depend on latitude, gravity, scale factor and earth's rotation rate. By the multi-position combinations, the installation errors of the gyro and accelerometer are modulated into the sine and cosine functions, which can be identified respectively based on the least squares. In order to verify the correctness of the theoretical analysis, the SINS is experimented by a three-axis turntable, and the installation errors of the gyro and accelerometer are identified respectively according to the proposed method. After the compensation of the installation error, the accuracy of the SINS is improved significantly.

scholarly journals A Simpler GMRES Method for Oscillatory Integrals with Irregular Oscillations

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Qinghua Wu ◽  
Meiying Xiang
Keyword(s):  
Theoretical Analysis ◽  
Matrix Factorization ◽  
Numerical Experiments ◽  
Oscillatory Integral ◽  
Oscillatory Integrals ◽  
New Method ◽  
Gmres Method ◽  
Hessenberg Matrix

A simpler GMRES method for computing oscillatory integral is presented. Theoretical analysis shows that this method is mathematically equivalent to the GMRES method proposed by Olver (2009). Moreover, the simpler GMRES does not require upper Hessenberg matrix factorization, which leads to much simpler program and requires less work. Numerical experiments are conducted to illustrate the performance of the new method and show that in some cases the simpler GMRES method could achieve higher accuracy than GMRES.

Simulation of Planar Dynamic Mechanical Systems With Changing Topologies: Part I — Characterization and Prediction of the Kinematic Constraint Changes

1987 ◽  
Author(s):  
B. J. Gilmore ◽  
R. J. Cipra
Keyword(s):  
Equations Of Motion ◽  
Mechanical Systems ◽  
Rigid Bodies ◽  
State Variables ◽  
Kinematic Constraint ◽  
Kinematic Constraints ◽  
Force Closure ◽  
Simulation Strategy ◽  
Reaction Forces ◽  
Discontinuous Equations

Abstract Due to changes in the kinematic constraints, many mechanical systems are described by discontinuous equations of motion. This paper addresses those changes in the kinematic constraints which are caused by planar bodies contacting and separating. A strategy to automatically predict and detect the kinematic constraint changes, which are functions of the system dynamics, is presented in Part I. The strategy employs the concepts of point to line contact kinematic constraints, force closure, and ray firing together with the information provided by the rigid bodies’ boundary descriptions, state variables, and reaction forces to characterize the kinematic constraint changes. Since the strategy automatically predicts and detects constraint changes, it is capable of simulating mechanical systems with unpredictable or unforeseen changes in topology. Part II presents the implementation of the characterizations into a simulation strategy and presents examples.

Electrical Elements in Reduction of Mechanical Vibrations

2013 ◽  
Vol 371 ◽  
pp. 657-661 ◽  
Author(s):  
Katarzyna Białas
Keyword(s):  
Mechanical System ◽  
Vibration Reduction ◽  
Mechanical Systems ◽  
Synthetic Method ◽  
Basic System ◽  
Mechanical Vibrations ◽  
Parametric Synthesis ◽  
System Designer ◽  
Active Elements ◽  
Reduction Methods

This work presents methods of reduction of the vibration of mechanical systems by means of active elements as well as examples of implementation of active reduction of vibration by means of electrical elements [. This work also describes a structural and parametric synthesis, which can be defined as the design of systems meeting specific requirements. These requirements refer to the frequency values of the systems vibration. The presented approach i.e. a non-classical synthetic method applied in designing mechanical systems, one (as early as at the design and construction stage) may verify future systems [1-. This work presents the description of vibration reduction methods. The most popular methods are passive, active and semi-active. An important aspect of this work is the presentation of several possibilities of the physical implementation of active subsystems. In examples active subsystems consisted of the following electric elements is coil with a movable core. In this work is presents influence of electrical subsystem to basic mechanical system. Designer should analyse the resultant systems and investigate the interaction between the subsystems and the basic system [4-.

Sign in / Sign up

Export Citation Format

Share Document