scholarly journals Design and Characterization of a Planar Motor Drive Platform Based on Piezoelectric Hemispherical Shell Resonators

Actuators ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 187
Author(s):  
Frank Schiele ◽  
Bernd Gundelsweiler
Keyword(s):  
Open Loop ◽  
Excitation Voltage ◽  
Piezoelectric Resonator ◽  
Measured Velocity ◽  
Driving Mode ◽  
Hemispherical Shell ◽  
Propulsion Force ◽  
Working Principle ◽  
Oscillating Mode

In this study, a planar ultrasonic motor platform is presented that uses three half-side excited piezoelectric hemispherical shell resonators. To understand the working principle and the harmonic vibration behavior of the piezoelectric resonator, the trajectory of the friction contact was measured in free-oscillating mode at varying excitation frequencies and voltages. The driving performance of the platform was characterized with transport loads up to 5 kg that also serve as an influencing downforce for the friction motor. The working range for various transport loads and electrical voltages up to 30 V is presented. Undesirable noise and parasitic oscillations occur above the detected excitation voltage ranges, depending on the downforce. Therefore, minimum and maximum values of the excitation voltage are reported, in which the propulsion force and the speed of the planar motor can be adjusted, and noiseless motion applies. The multidimensional driving capacity of the platform is demonstrated in two orthogonal axes and one rotary axis in open-loop driving mode, by measuring forces and velocities to confirm its suitability as a planar motor concept. The maximum measured propulsion force of the motor was 7 N with a transport load of 5 kg, and its maximum measured velocity was 77 mm/s with a transport load of 3 kg.

scholarly journals Piezoelectric MEMS Resonators for Cigarette Particle Detection

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 145 ◽  
Author(s):  
Javier Toledo ◽  
Víctor Ruiz-Díez ◽  
Maik Bertke ◽  
Hutomo Suryo Wasisto ◽  
Erwin Peiner ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Closed Loop ◽  
Low Cost ◽  
Open Loop ◽  
Piezoelectric Resonator ◽  
Particle Detection ◽  
Interface Circuit ◽  
Mems Resonators ◽  
Loading Effects ◽  
Working Principle

In this work, we demonstrate the potential of a piezoelectric resonator for developing a low-cost sensor system to detect microscopic particles in real-time, which can be present in a wide variety of environments and workplaces. The sensor working principle is based on the resonance frequency shift caused by particles collected on the resonator surface. To test the sensor sensitivity obtained from mass-loading effects, an Aluminum Nitride-based piezoelectric resonator was exposed to cigarette particles in a sealed chamber. In order to determine the resonance parameters of interest, an interface circuit was implemented and included within both open-loop and closed-loop schemes for comparison. The system was capable of tracking the resonance frequency with a mass sensitivity of 8.8 Hz/ng. Although the tests shown here were proven by collecting particles from a cigarette, the results obtained in this application may have interest and can be extended towards other applications, such as monitoring of nanoparticles in a workplace environment.

The Electricity Design of Pressure Sensor

2013 ◽  
Vol 438-439 ◽  
pp. 539-542
Author(s):  
Tao Li ◽  
Guo Jing Ren ◽  
Li Feng Qi ◽  
Zhi Min Liu
Keyword(s):  
Mechanical System ◽  
Pressure Sensor ◽  
Wheatstone Bridge ◽  
Micro Electro Mechanical System ◽  
Open Loop ◽  
Bridge Design ◽  
Piezoresistive Pressure Sensor ◽  
Working Principle

The relative discussion and research of Micro-Electro-Mechanical System (MEMS) and pressure sensor is carried out in this paper. The working principle of pressure sensor is analyzed, and the cantilever piezoresistive pressure sensor is studied in details. The electricity design of pressure sensor is researched. The open loop Wheatstone-bridge design is adopted in this paper, which adds the freedom of disposing circuit.

scholarly journals SEARCHING AND MEASUREMENT OF FUNCTIONAL VOIDS BY MEANS OF GPR TOMOGRAPHY BY THE EXAMPLE OF TWO COLUMNS

2017 ◽  
Vol 13 (1) ◽  
pp. 94-109 ◽  
Author(s):  
Marina S. Sudakova ◽  
Eugeniya B. Terentieva ◽  
Alexey Yu. Kalashnikov
Keyword(s):  
Electromagnetic Waves ◽  
High Quality ◽  
Spherical Void ◽  
Engineering Structures ◽  
Measured Velocity ◽  
Inversion Result ◽  
Single Fold ◽  
Solid Part ◽  
Tomography Method

he present article focuses on GPR tomography method potential aimed at the search of functional voids and estimation of their sizes in engineering structures. The size of voids is assumed to be greater than the wavelength for usable frequency. Two examples of the GPR tomographic survey are examined: 1) a square con-crete pillar with granite coating and a square void in the center, 2) cylindrical granite column with functional spherical void which has iron walls. The following issues are considered in the article: the method, the structure of the acquired data, the picking of wanted waves, the analysis of tomographic inversion result, compared with the result of commonly used single-fold antenna geometry GPR. As a result of the research performed it was demonstrated that GPR tomography represents a good solution for the problem of detection, delineation and characterization of voids inside engineering structures. The velocity of electromagnetic waves propagated within the solid part of the column (concrete and granite) was accurately measured. The measured velocity can be con-sidered to the basis for physical properties estimation, for example humidity, voids ratio etc. The acquired quan-titative results are characterized by high quality and are more reliable compared to the results of single-fold GPR survey.

scholarly journals Characterization of an Aluminum Alloy Hemispherical Shell Fabricated via Direct Metal Laser Melting

JOM ◽  
2016 ◽  
Vol 68 (3) ◽  
pp. 1000-1011 ◽  
Author(s):  
T. G. Holesinger ◽  
J. S. Carpenter ◽  
T. J. Lienert ◽  
B. M. Patterson ◽  
P. A. Papin ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Laser Melting ◽  
Hemispherical Shell

Design and characterization of a hybrid soft gripper with active palm pose control

2020 ◽  
Vol 39 (14) ◽  
pp. 1668-1685 ◽  
Author(s):  
Vignesh Subramaniam ◽  
Snehal Jain ◽  
Jai Agarwal ◽  
Pablo Valdivia y Alvarado
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Composite Structure ◽  
Element Model ◽  
Open Loop ◽  
Aspect Ratios ◽  
Maximum Payload ◽  
Wide Range ◽  
Pose Control

The design and characterization of a soft gripper with an active palm to control grasp postures is presented herein. The gripper structure is a hybrid of soft and stiff components to facilitate integration with traditional arm manipulators. Three fingers and a palm constitute the gripper, all of which are vacuum actuated. Internal wedges are used to tailor the deformation of a soft outer reinforced skin as vacuum collapses the composite structure. A computational finite-element model is proposed to predict finger kinematics. Thanks to its active palm, the gripper is capable of grasping a wide range of part geometries and compliances while achieving a maximum payload of 30 N. The gripper natural softness enables robust open-loop grasping even when components are not properly aligned. Furthermore, the grasp pose of objects with various aspect ratios and compliances can be robustly maintained during manipulation at linear accelerations of up to 15 m/s2 and angular accelerations of up to 5.23 rad/s2.

New control methodology for a morphing wing demonstrator

2017 ◽  
Vol 232 (8) ◽  
pp. 1479-1494 ◽  
Author(s):  
Michel Joël Tchatchueng Kammegne ◽  
Yvan Tondji ◽  
Ruxandra Mihaela Botez ◽  
Lucian Teodor Grigorie ◽  
Mahmoud Mamou ◽  
...  
Keyword(s):  
Pressure Sensors ◽  
Open Loop ◽  
Post Processing ◽  
Pressure Data ◽  
Morphing Wing ◽  
Subsonic Wind Tunnel ◽  
Logic Control ◽  
Flexible Part ◽  
Control Methodology

A morphing wing can improve the aircraft aerodynamic performance by changing the wing airfoil depending on the flight conditions. In this paper, a new control methodology is presented for a morphing wing demonstrator tested in a subsonic wind tunnel in the open-loop configuration. Actuators integrated inside the wing are used to modify the flexible structure, which is an integral part of the wing. In this project, the actuators are made in-house and controlled with logic control, which is developed within the main frame of this work. The characterization of the flow (laminar or turbulent) over the wing is obtained starting from the pressure signals measured over the flexible part of the wing (upper surface). The signals are acquired by using some pressure sensors (Kulite sensors) incorporated in this flexible part of the wing upper surface. The technique used to collect Kulite pressure data and the post-processing methodology are explained. The recorded pressure data are sometimes subjected to noise, which is filtered before being processed. The standard deviation and power spectrum visualization of the pressure data approaches are used to evaluate the quality of the flow over the wing and estimate the transition point position in the area monitored by the Kulite sensors. In addition, infrared thermography visualization is implemented to observe the transition region over the entire wing upper surface, and to validate the methodology applied to the pressure data in this way. The demonstrator measures 1.5 m chordwise and 1.5 m spanwise. Four miniature actuators fixed on two actuation lines are used to morph the wing. The wing is also equipped with a rigid aileron. The experimental aerodynamic results obtained after post processing validate the numerical prediction for the transition location.

New Open Loop Control Improves Linearity of Piezoelectric Actuators

2011 ◽  
Vol 211-212 ◽  
pp. 520-524
Author(s):  
Yu Ting Ma ◽  
Liang Huang ◽  
Wei Wei Shao
Keyword(s):  
Charge Pump ◽  
Open Loop ◽  
Driving Voltage ◽  
Nonlinear Relationship ◽  
Open Loop Control ◽  
Loop Control ◽  
Driving Mode ◽  
Creep Characteristics ◽  
Piezoelectric Stack Actuator ◽  
Capacitor Charge

The piezoelectric material is subject to hysteresis and creep resulting in a nonlinear relationship between the applied voltage and the output mechanical displacement. An approach for compensation of both the hysteresis and creep characteristics of a piezoelectric stack actuator is proposed by utilizing a switched capacitor charge pump. The new charge pump transfers the same amount of charges to the piezoelectric actuator quantitatively, and the actuator will be excited to change its length with constant step. Compared with voltage driving mode, experiments show that both creep and hysteresis of the piezoelectric stack driven by the charge pump are effectively reduced. A hysteresis reduction of 86.10% at 0.01Hz and 94.36% at 5Hz is achieved. At the maximum driving voltage, a creep reduction of 77% is obtained.

scholarly journals The research of the pulse oxygen supply based on the fuzzy control technology

2018 ◽  
Vol 189 ◽  
pp. 06012
Author(s):  
Faling Hu ◽  
Tongfeng Niu ◽  
Jun Yao ◽  
Bingyan Cui ◽  
Haoxing Xu ◽  
...  
Keyword(s):  
Control System ◽  
Fuzzy Control ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Fuzzy Control System ◽  
Loop Control System ◽  
Working Principle ◽  
The Stability ◽  
Close Loop Control

According to the working principle of pulse oxygen supplies, we analyze how to realize the control of the oxygen flow by double different valves. a two-dimensional fuzzy control system is proposed to solve the unstable problem, which is brought by the shortcomings of the open-loop control system. We add a new parameter, the rate of the differential pressure signal changes, which contributes to a close –loop control system and increases the stability of the system. The experiments and the data show that the fuzzy control system make the process of breathing much more comfortable and solve the hysteresis and overshoot caused by the open-loop control system. The product reliability has been greatly improved.

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