Development of a two-degree-of-freedom piezoelectric motor using single plate vibrator

2011 ◽  
Vol 226 (4) ◽  
pp. 1036-1052 ◽  
Author(s):  
G-M Cheng ◽  
K Guo ◽  
P Zeng ◽  
Y-M Sun
Keyword(s):  
Numerical Models ◽  
Excitation Frequency ◽  
Degree Of Freedom ◽  
Analytical Models ◽  
Experimental Result ◽  
Piezoelectric Motor ◽  
Piezoelectric Vibrator ◽  
Contact Points ◽  
Numerical Result ◽  
Two Degree Of Freedom

A two-degree-of-freedom piezoelectric motor using only one piezoelectric ceramic was proposed based on two vibration modes (B32 and B23) of a rectangular plate piezoelectric vibrator. The working principle was elaborated. Analytical and numerical models were established in order to design the piezoelectric vibrator. Calculations with finite element method were carried out using ANSYS software to validate the analytical models and demonstrate the elliptical trajectory of the four contact points between the stator and the sphere. Experimental result on the prototype shows that the numerical result including resonance frequency and elliptical motion of the motor indicate good agreement with the experimental one. The rotation speed around an axial along the direction of length of the rectangular piezoelectric vibrator of the motor is 37.7 r/min under the drive voltage 90 V and excitation frequency 44 kHz.

Experimental Forced Response Analysis of Two-Degree-of-Freedom Piecewise-Linear Systems With a Gap

2020 ◽  
Author(s):  
Akira Saito ◽  
Junta Umemoto ◽  
Kohei Noguchi ◽  
Meng-Hsuan Tien ◽  
Kiran D’Souza
Keyword(s):  
Piecewise Linear ◽  
Excitation Frequency ◽  
Forced Response ◽  
Degree Of Freedom ◽  
Linear Oscillator ◽  
Phase Portraits ◽  
Response Analysis ◽  
Experimental Setup ◽  
The Masses ◽  
Two Degree Of Freedom

Abstract In this paper, an experimental forced response analysis for a two degree of freedom piecewise-linear oscillator is discussed. First, a mathematical model of the piecewise linear oscillator is presented. Second, the experimental setup developed for the forced response study is presented. The experimental setup is capable of investigating a two degree of freedom piecewise linear oscillator model. The piecewise linearity is achieved by attaching mechanical stops between two masses that move along common shafts. Forced response tests have been conducted, and the results are presented. Discussion of characteristics of the oscillators are provided based on frequency response, spectrogram, time histories, phase portraits, and Poincaré sections. Period doubling bifurcation has been observed when the excitation frequency changes from a frequency with multiple contacts between the masses to a frequency with single contact between the masses occurs.

Vibration Control of Two-Degree-of-Freedom Structures Utilizing Sloshing in Nearly Square Tanks

2017 ◽  
Vol 12 (5) ◽  
Author(s):  
Takashi Ikeda ◽  
Yuji Harata ◽  
Shota Ninomiya
Keyword(s):  
Vibration Control ◽  
Equations Of Motion ◽  
Excitation Frequency ◽  
Harmonic Excitation ◽  
Degree Of Freedom ◽  
Response Curves ◽  
Chaotic Motions ◽  
Installation Angle ◽  
Two Degree Of Freedom ◽  
Theoretical Results

This paper investigates the vibration control of a towerlike structure with degrees of freedom utilizing a square or nearly square tuned liquid damper (TLD) when the structure is subjected to horizontal, harmonic excitation. In the theoretical analysis, when the two natural frequencies of the two-degree-of-freedom (2DOF) structure nearly equal those of the two predominant sloshing modes, the tuning condition, 1:1:1:1, is nearly satisfied. Galerkin's method is used to derive the modal equations of motion for sloshing. The nonlinearity of the hydrodynamic force due to sloshing is considered in the equations of motion for the 2DOF structure. Linear viscous damping terms are incorporated into the modal equations to consider the damping effect of sloshing. Van der Pol's method is employed to determine the expressions for the frequency response curves. The influences of the excitation frequency, the tank installation angle, and the aspect ratio of the tank cross section on the response curves are examined. The theoretical results show that whirling motions and amplitude-modulated motions (AMMs), including chaotic motions, may occur in the structure because swirl motions and Hopf bifurcations, followed by AMMs, appear in the tank. It is also found that a square TLD works more effectively than a conventional rectangular TLD, and its performance is further improved when the tank width is slightly increased and the installation angle is equal to zero. Experiments were conducted in order to confirm the validity of the theoretical results.

Touch Recognition Using a Passive Large Compliance Robotic Finger With Internal Sensors for Planar Applications

1999 ◽  
Author(s):  
Dennis W. Hong ◽  
Raymond J. Cipra
Keyword(s):  
Deflection Angle ◽  
Low Cost ◽  
Three Dimensional ◽  
Outer Edge ◽  
Degree Of Freedom ◽  
Two Dimensional ◽  
Outline Shape ◽  
Contact Points ◽  
Manipulator Arm ◽  
Two Degree Of Freedom

Abstract In this paper, a touch-sensing device consisting of a passive large compliance robotic finger with internal sensors, and algorithms for using this device for recognition applications are presented. These algorithms include recognition of the two-dimensional projected outline shape and dimensions of an object, and recognition of the three-dimensional convex outline height profiles of an object. The two-dimensional outline of an object is identified by tracing the object’s outer edge with the robotic finger and returning the XY coordinates of selected outline contact points and their tangent line directions. Recognition of the three-dimensional convex outline height profiles of an object is done by observing the change of the robotic finger deflection angle while moving the finger toward the object in contact. The feasibility of the device and the algorithms developed were successfully tested for planar applications by both analytical simulations and by experiments using a simple two-degree-of-freedom inverted joystick attached to the end of a planar manipulator arm. Simplicity, low cost, and easy implementation are some of the major benefits of using the proposed touch-sensing device.

scholarly journals Monolithic 2 DOF fully compliant space pointing mechanism

2013 ◽  
Vol 4 (2) ◽  
pp. 381-390 ◽  
Author(s):  
E. G. Merriam ◽  
J. E. Jones ◽  
S. P. Magleby ◽  
L. L. Howell
Keyword(s):  
Numerical Models ◽  
Degree Of Freedom ◽  
Solar Array ◽  
Design Decisions ◽  
Detailed Design ◽  
Final Design ◽  
Project Objectives ◽  
Two Degree Of Freedom ◽  
Prototype Testing

Abstract. This paper describes the conception, modeling, and development of a fully compliant two-degree-of-freedom pointing mechanism for application in spacecraft thruster, antenna, or solar array systems. The design objectives and the advantages of a compliant solution are briefly discussed. Detailed design decisions to meet project objectives are described. Analytical and numerical models are developed and subsequently verified by prototype testing and measurements in several iterations. A final design of the 3-D printed titanium monolithic pointing mechanism is described in detail and its performance is measured.

scholarly journals Passive Prosthetic Foot Shape and Size Optimization Using Lower Leg Trajectory Error

2017 ◽  
Author(s):  
Kathryn M. Olesnavage ◽  
Amos G. Winter
Keyword(s):  
Optimal Design ◽  
Compliant Mechanism ◽  
Lower Leg ◽  
Degree Of Freedom ◽  
Analytical Models ◽  
Element Analysis ◽  
Trajectory Error ◽  
Prosthetic Foot ◽  
Two Degree Of Freedom ◽  
Shape And Size

A method is presented to optimize the shape and size of a passive prosthetic foot using the Lower Leg Trajectory Error (LLTE) as the design objective. The LLTE is defined as the root-mean-square error between the lower leg trajectory calculated for a given prosthetic foot by finding the deformed shape of the foot under typical ground reaction forces and a target physiological lower leg trajectory obtained from published gait data for able-bodied walking. In previous work, the design of simple two degree-of-freedom analytical models consisting of rigid structures, rotational joints with constant stiffness, and uniform cantilevered beams, have been optimized for LLTE. However, prototypes built to replicate these simple models were large, heavy, and overly complex. In this work, the size and shape of a single-part compliant prosthetic foot keel made out of nylon 6/6 was optimized for LLTE to produce a light weight, low cost, and easily manufacturable prosthetic foot design. The shape of the keel was parameterized as a wide Bézier curve, with constraints ensuring that only physically meaningful shapes were considered. The LLTE value for each design was evaluated using a custom MATLAB script, which ran ADINA finite element analysis software to find the deformed shape of the prosthetic keel under multiple loading scenarios. The optimization was performed by MATLAB’s built-in genetic algorithm. After the optimal design for the keel was found, a heel was added to structure, sized such that when the user’s full weight acted on the heel, the structure had a factor of safety of two. The resulting optimal design has a lower LLTE value than the two degree-of-freedom analytical models, at 0.154 compared to 0.172, 0.187, and 0.269 for the two degree-of-freedom models. At 412 g, the optimal wide curve foot is nearly half the mass of the lightest prototype built from the previous models, which was 980 g. The design found through this compliant mechanism optimization method is thus far superior to the two degree-of-freedom models previously considered.

Sign in / Sign up

Export Citation Format

Share Document