Development of 2-DOF Hybrid Actuator System

2012 ◽  
Vol 523-524 ◽  
pp. 733-738
Author(s):  
Ryota Okeya ◽  
Manabu Aoyagi
Keyword(s):  
Force Feedback ◽  
Piezoelectric Actuators ◽  
Degree Of Freedom ◽  
Performance Characteristics ◽  
The Other ◽  
Haptic Display ◽  
Different Types ◽  
Actuator System ◽  
Two Degree Of Freedom ◽  
Hybrid Actuator

Ordinal force-feedback devices mainly employ electromagnetic motors (EMMs), and are excellent at expressing springy sensations. However, it is not easy to express a realistic sense of hardness and roughness using such devices. On the other hand, an actuator system (AS) using multilayered piezoelectric actuators exhibits performance characteristics that are opposite to those of an ordinal AS using an EMM. The objective of the present study is to develop an ideal AS for a haptic display. A two-degree-of-freedom AS utilizing a pair of hybrid AS units, each consisting of an EMM, an ultrasonic motor and a piezoelectric clutch, is proposed and evaluated. Such an arrangement allows the different types of actuators to complement each other, thus compensating for their individual weaknesses. This hybrid AS can expand the range of representable sensations. The results show that the proposed AS can realistically express both hardness and softness by switching between actuator combinations.

Design of a 2 DOF Shape Memory Alloy Actuator Using SMA Springs

2021 ◽  
Author(s):  
Hussein F. M. Ali ◽  
Youngshik Kim
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Open Loop ◽  
Degree Of Freedom ◽  
Biologically Inspired ◽  
Loop Control ◽  
Actuator System ◽  
Sma Actuator ◽  
Sma Spring ◽  
Two Degree Of Freedom

Abstract In this paper, we developed two degree of freedom shape memory alloy (SMA) actuator using SMA springs. This module can be applied easily to various applications: device holder, artificial finger, grippes, fish robot, and many other biologically inspired applications, where small size and small wight of the actuator are very critical. This actuator is composed of two sets of SMA springs: one set is for the rotation around the X axis (roll angle) and the other set is for the rotation around the Y axis (pitch angle). Each set contains two elements: one SMA spring and one antagonistic SMA spring. We used an inertia sensor (IMU) and two potentiometers for angles feedback. The SMA actuator system is modeled mathematically and then tested experimentally in open-loop and closed-loop control. We designed and experimentally tuned a proportional integrator derivative (PID) controller to follow the set points and to track the desired trajectories. The main goal of the presented controller is to control roll and pitch angles simultaneously in order to satisfy set points and trajectories within the work space. The experimental results show that the two degree of freedom SMA actuator system follows the desired setpoints with acceptable rise time and overshoot.

scholarly journals Pendekatan Eksperimen Karakteristik Respon Getaran Sistem Two Degree of Freedom dengan Penambahan Independent Dual Dynamic Vibration Absorber

2019 ◽  
Vol 3 (2) ◽  
pp. 85
Author(s):  
Susastro Susastro ◽  
Novi Indah Riani
Keyword(s):  
Vibration Reduction ◽  
Degree Of Freedom ◽  
The Other ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Maximum Reduction ◽  
Dynamic Vibration ◽  
Translational Vibration ◽  
Mathematical Equations ◽  
Two Degree Of Freedom

Vibration is one of the problems that must be reduced in a vehicle. There are many ways to reduce vibration in vehicles, one of them is by adding Dynamic vibration absorber (DVA). While Dual Dynamic vibration absorber (dDVA) is a DVA period that is able to move in the translational direction given to the system to reduce translation vibration and when there is resonance. Translation DVA is an additional type of time used to reduce the vibration of the translation direction. So far there is not much research related to the use of translational DVA to reduce rotational vibrations as well as translation. In this study, a study was conducted related to the use of independent double translational DVA (dDVA) to reduce translation vibrations as well as rotation of the beam. The research was conducted by modeling the system obtained into mathematical equations and simulations were carried out to determine the characteristics of vibrations that arise. In the simulation, one of the DVA periods is placed at the center of the main system period, while the other DVA period is given a change between the center period and the end of the system. The results of the study show that the maximum reduction in translational vibration is 95.51% and occurs when the absorber is placed at the center of the system, while the maximum rotation vibration reduction is 56.62% and is obtained when the system is given with an arm ratio of 1 and zero.

Vibration Response of Linear Damped Complex Systems

1963 ◽  
Vol 30 (1) ◽  
pp. 70-74 ◽  
Author(s):  
Robert Plunkett
Keyword(s):  
Linear System ◽  
Complex Systems ◽  
Normal Modes ◽  
Continuous System ◽  
Vibration Response ◽  
Degree Of Freedom ◽  
The Other ◽  
Maximum Response ◽  
Approximate Expressions ◽  
Two Degree Of Freedom

Hahnkamm has found the changes in the amplitudes of each of the two maxima of the unit vibration response of a two-degree-of-freedom linear system as the strength of the single linear dashpot is changed. This paper develops two approximate expressions for the change in all of the response maxima of a multidegree or continuous system as the dashpot constant of the single linear damper is changed. One of these approximations is derived from a perturbation solution around the minimax values, and the other is derived from an expansion in normal modes. These expressions are useful in determining the sensitivity of the maximum response value to small changes in the damping constant.

scholarly journals Application of Extended Homotopy Analysis Method to the Two-Degree-of-Freedom Coupled van der Pol-Duffing Oscillator

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Y. H. Qian ◽  
S. M. Chen ◽  
L. Shen
Keyword(s):  
Homotopy Analysis Method ◽  
Duffing Oscillator ◽  
Approximate Solutions ◽  
Analytical Approximation ◽  
Degree Of Freedom ◽  
Analysis Method ◽  
Van Der Pol ◽  
Different Types ◽  
Homotopy Analysis ◽  
Two Degree Of Freedom

The extended homotopy analysis method (EHAM) is presented to establish the analytical approximate solutions for two-degree-of-freedom (2-DOF) coupled van der Pol-Duffing oscillator. Meanwhile, the comparisons between the results of the EHAM and standard Runge-Kutta numerical method are also presented. The results demonstrate that the analytical approximate solutions of the EHAM agree well with the numerical integration solutions. For EHAM as an analytical approximation method, we are not sure whether it can apply to all of the nonlinear systems; we can only verify its effectiveness through specific cases. As a result of the existence of nonlinear terms, we must study different types of systems, no matter from the complication of calculation and physical significance.

Two-Degree-of-Freedom Decoupled Nonredundant Cable-Loop-Driven Parallel Mechanism

2013 ◽  
Vol 6 (1) ◽  
Author(s):  
Hanwei Liu ◽  
Clément Gosselin ◽  
Thierry Laliberté
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Degree Of Freedom ◽  
The Other ◽  
End Effector ◽  
Two Degrees Of Freedom ◽  
Actuation Redundancy ◽  
Rigid Link ◽  
Force Closure ◽  
Two Degree Of Freedom

A novel two-degree-of-freedom (DOF) cable-loop slider-driven parallel mechanism is introduced in this paper. The novelty of the mechanism lies in the fact that no passive rigid-link mechanism or springs are needed to support the end-effector (only cables are connected to the end-effector) while at the same time there is no actuation redundancy in the mechanism. Sliders located on the edges of the workspace are used and actuation redundancy is eliminated while providing force closure everywhere in the workspace. It is shown that the two degrees of freedom of the mechanism are decoupled and only two actuators are needed to control the motion. There are two cable loops for each direction of motion: one acts as the actuating loop while the other is the constraint loop. Due to the simple geometric design, the kinematic and static equations of the mechanism are very compact. The stiffness of the mechanism is also analyzed in the paper. It can be observed that the mechanism's stiffness is much higher than the stiffness of the cables. The proposed mechanism's workspace is essentially equal to its footprint and there are no singularities.

Free Periodic Motions of an Undamped Two-Degree-of-Freedom Oscillatory System With Nonlinear Unsymmetrical Elasticity

1950 ◽  
Vol 17 (2) ◽  
pp. 185-190
Author(s):  
Walter W. Soroka
Keyword(s):  
Nonlinear Systems ◽  
Linear Systems ◽  
Oscillatory System ◽  
Degree Of Freedom ◽  
The Other ◽  
Periodic Motions ◽  
Deflection Curve ◽  
Approximate Treatment ◽  
Load Deflection Curve ◽  
Two Degree Of Freedom

Abstract Precise solutions are presented for a two-degree-of-freedom oscillatory system containing a preset spring. Such a system is characteristic of an aircraft propeller-engine-supercharger installation. The periodic free motions obtained indicate the possibility of highly unconventional motions when the nonlinearity is pronounced, motions which may be easily overlooked in the usual approximate treatment of nonlinear systems. The results presented in this paper show that one mass may oscillate several times while the other mass is going through one oscillation. The ratio of oscillations of one mass with respect to the other changes with amplitude. By considering the load-deflection curve for the nonlinear spring to be a broken line, periodic motions may be obtained to any desired degree of precision by combining conventional general solutions for two-degree-of-freedom linear systems.

Two-Degree-of-Freedom Decoupled Non-Redundant Cable-Loop-Driven Parallel Mechanism

2012 ◽  
Author(s):  
Hanwei Liu ◽  
Clément Gosselin ◽  
Thierry Laliberté
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Degree Of Freedom ◽  
The Other ◽  
Dynamic Equations ◽  
End Effector ◽  
Actuation Redundancy ◽  
Rigid Link ◽  
Force Closure ◽  
Two Degree Of Freedom

A novel two-degree-of-freedom cable-loop slider-driven parallel mechanism is introduced in this paper. The two degrees of freedom of the mechanism are decoupled and only two actuators are needed to control the motion. There are two cable loops for each direction of motion: one acts as the actuating loop while the other is the constraint loop. Due to the simple geometric design, the kinematic and static equations of the mechanism are very compact. The stiffness of the mechanism is also analyzed in the paper. It can be observed that the mechanism’s stiffness is much higher than the stiffness of the cables. Finally, the dynamic equations of the mechanism, including the compliance and the damping of the cables are obtained. The proposed mechanism’s workspace is essentially equal to its footprint and there are no singularities. The mechanism does not require the use of a rigid-link passive bridge and trolley (only cables are connected to the end-effector). Sliders located on the edges of the workspace are used and actuation redundancy is eliminated while providing force closure everywhere in the workspace.

scholarly journals Development of a Mechatronic System for Demonstration Purposes

2021 ◽  
Vol 15 (1) ◽  
pp. 19-24
Author(s):  
István Györkovács ◽  
Zoltán Forgó
Keyword(s):  
Software Package ◽  
Degree Of Freedom ◽  
Modular System ◽  
Mechatronic System ◽  
Rotary Joint ◽  
Different Types ◽  
Two Degree Of Freedom ◽  
Energy Converters

Abstract The aim of the paper is to present a modular system, with the help of which it is possible to reveal the structure and analysis of a mechatronic system, taking into account several disciplines that contribute to the structure of the system. The planned system will include devices from different disciplines, the operation and coordination of which will be observable. The designed system is a two-degree-of-freedom mechanism with a translational and a rotary joint. The movement of the joints are obtained by different types of energy converters (pneumatic, electric). The replacement of the different types of drives can be performed quickly and easily without drastically changing the system setup. The simulations are implemented using the MATLAB Simscape software package.

Comparison of Open Chain and Closed Chain Planar Two Degree of Freedom Manipulator for Positional Error

2014 ◽  
Vol 6 (2) ◽  
Author(s):  
H. P. Jawale ◽  
H. T. Thorat
Keyword(s):  
Geometric Approach ◽  
Degree Of Freedom ◽  
The Other ◽  
Dimensionless Number ◽  
Positional Error ◽  
Positional Accuracy ◽  
Open Chain ◽  
Closed Chain ◽  
Error Index ◽  
Two Degree Of Freedom

Open chain and closed chain manipulators are designed for specific objectives. Closed chain five bar manipulator is possible to be configured as a substitute to an open chain two degree of freedom (DoF) manipulator. Positional accuracy is one of the factors for performance evaluation, characterizing suitability of a configuration over the other. Present paper attempts comparative analysis of positional inaccuracy of closed chain five bar manipulator and serial chain configuration. Both manipulators are modeled for positional deviations under identical specifications considering randomness due to joint clearances and backlash in drive. The maximum positional inaccuracy is expressed in terms of dimensionless number as error index (EI) to estimate the comparative behavior of the manipulators. Positional error under influence of backlash and clearances is quantified. Comparison of two configurations is presented and conditional superiority of a configuration over the other is commented using geometric approach.

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