A low-frequency longitudinal vibration transducer with a helical slot structure

2019 ◽  
Vol 145 (5) ◽  
pp. 2948-2954
Author(s):  
Jiaai Bai ◽  
Guangbin Zhang ◽  
Xiaofeng Zhang
Keyword(s):  
Longitudinal Vibration ◽  
Low Frequency ◽  
Vibration Transducer ◽  
Slot Structure

scholarly journals Spiral Sound Wave Transducer Based on the Longitudinal Vibration

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3674 ◽  
Author(s):  
Wei Lu ◽  
Yu Lan ◽  
Rongzhen Guo ◽  
Qicheng Zhang ◽  
Shichang Li ◽  
...  
Keyword(s):  
Sound Wave ◽  
Longitudinal Vibration ◽  
Three Dimensional ◽  
Low Frequency ◽  
Sound Field ◽  
Field Measurements ◽  
Sound Waves ◽  
Underwater Sound ◽  
Three Dimensional Finite Element ◽  
Wave Transducer

A spiral sound wave transducer comprised of longitudinal vibrating elements has been proposed. This transducer was made from eight uniform radial distributed longitudinal vibrating elements, which could effectively generate low frequency underwater acoustic spiral waves. We discuss the production theory of spiral sound waves, which could be synthesized by two orthogonal acoustic dipoles with a phase difference of 90 degrees. The excitation voltage distribution of the transducer for emitting a spiral sound wave and the measurement method for the transducer is given. Three-dimensional finite element modeling (FEM)of the transducer was established for simulating the vibration modes and the acoustic characteristics of the transducers. Further, we fabricated a spiral sound wave transducer based on our design and simulations. It was found that the resonance frequency of the transducer was 10.8 kHz and that the transmitting voltage resonance was 140.5 dB. The underwater sound field measurements demonstrate that our designed transducer based on the longitudinal elements could successfully generate spiral sound waves.

Non-Linear Dynamic Magneto Electric Effects in Ferromagnetic-Ferroelectric Layered Composites

2013 ◽  
Author(s):  
Satenik Harutyunyan ◽  
Davresh Hasanyan
Keyword(s):  
Vibration Frequency ◽  
Strain Distribution ◽  
Longitudinal Vibration ◽  
Three Dimensional ◽  
Low Frequency ◽  
Structure Design ◽  
Experimental Results ◽  
Physical Parameters ◽  
Wide Range ◽  
Non Linear

A non-linear theoretical model including bending and longitudinal vibration effects was developed for predicting the magneto electric (ME) effects in a laminate bar composite structure consisting of magnetostrictive and piezoelectric multi-layers. If the magnitude of the applied field increases, the deflection rapidly increases and the difference between experimental results and linear predictions becomes large. However, the nonlinear predictions based on the present model well agree with the experimental results within a wide range of applied electric field. The results of the analysis are believed to be useful for materials selection and actuator structure design of actuator in actuator fabrication. It is shown that the problem for bars of symmetrical structure is not divided into a plane problem and a bending problem. A way of simplifying the solution of the problem is found by an asymptotic method. After solving the problem for a laminated bar, formula that enable one to change from one-dimensional required quantities to three dimensional quantities are obtained. The derived analytical expression for ME coefficients depend on vibration frequency and other geometrical and physical parameters of laminated composites. Parametric studies are presented to evaluate the influences of material properties and geometries on strain distribution and the ME coefficient. Analytical expressions indicate that the vibration frequency strongly influences the strain distribution in the laminates, and that these effects strongly influence the ME coefficients. It is shown that for certain values of vibration frequency (resonance frequency), the ME coefficient becomes infinity; as a particular case, low frequency ME coefficient were derived as well.

Actuating Mechanism and Design of a Double Driving Feet Linear Ultrasonic Motor Using Longitudinal Vibration Transducer

2010 ◽  
Vol 434-435 ◽  
pp. 775-778
Author(s):  
Wei Shan Chen ◽  
Ying Xiang Liu ◽  
Jun Kao Liu ◽  
Sheng Jun Shi
Keyword(s):  
Transient Analysis ◽  
Longitudinal Vibration ◽  
Structural Parameters ◽  
Ultrasonic Motor ◽  
Longitudinal Vibrations ◽  
Resonant Frequencies ◽  
Vibration Transducer ◽  
Linear Ultrasonic Motor ◽  
Piezoelectric Coupling ◽  
Vertical Vibrations

A double driving feet linear ultrasonic motor using longitudinal vibration transducer is proposed in this paper. The stator of proposed motor contains a horizontal transducer and two vertical transducers. The horizontal transducer includes two exponential shape horns located at the leading ends, and each vertical transducer contains one exponential shape horn. The horns intersected at the tip ends where located the driving feet. The horizontal and vertical vibrations of driving feet are generated by the longitudinal vibrations of horizontal and vertical transducers, respectively. Longitudinal vibrations are superimposed in the stator and generated elliptical motions at the driving feet. The two vibration modals of stator are gained with FEM, and the resonant frequencies of two vibration modals are degenerated by adjusting the structural parameters. Transient analysis of piezoelectric coupling states the good and strong elliptical motions of driving feet, and verifies the theoretical feasibility of proposed motor.

scholarly journals A Reduced-Order Model for Active Suppression Control of Vehicle Longitudinal Low-Frequency Vibration

2018 ◽  
Vol 2018 ◽  
pp. 1-22 ◽  
Author(s):  
Donghao Hao ◽  
Changlu Zhao ◽  
Ying Huang
Keyword(s):  
Longitudinal Vibration ◽  
Estimation Method ◽  
Low Frequency ◽  
Coupling Model ◽  
Torsional Stiffness ◽  
Model Parameters ◽  
Active Suppression ◽  
Low Frequency Vibration ◽  
Time Domain Response ◽  
The Time Domain

Establishing a prediction model, with linearity and few dof (degree of freedom), is a key step for the design of a control algorithm based on the modern control theory. In this paper, such a model is needed for active suppression of vehicle longitudinal low-frequency vibration. However, many dynamic processes in the vehicle have different effects on the vibration. Therefore, a detailed coupling model is firstly established, considering the dynamics of the torsional vibrations of the driveline and the tire, the tire force nonlinearity, and the vehicle vertical and pitch vibrations. Based on this model, sensitivity analysis is conducted and the results show that the tire slip, the torsional stiffness of the half-shaft, and the tire have great influences on the longitudinal vibration. Then a three-dof model is obtained by linearizing the tire slip into damping. A parameter estimation method is designed to obtain the model parameters. Finally, the model is validated. The time domain response, error analysis, and frequency response results demonstrate that the 3-dof model has a good consistency with the detailed coupling model. It is suitable as a control-oriented model.

scholarly journals Impact Dynamics of a Percussive System Based on Rotary-Percussive Ultrasonic Drill

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Yinchao Wang ◽  
Qiquan Quan ◽  
Hongying Yu ◽  
He Li ◽  
Deen Bai ◽  
...  
Keyword(s):  
High Speed ◽  
Longitudinal Vibration ◽  
Low Frequency ◽  
Load Condition ◽  
Camera System ◽  
Collision Model ◽  
Amplitude Vibration ◽  
Conservation Of Momentum ◽  
Mass Transfers ◽  
Drill Tool

This paper presents an impact dynamic analysis of a percussive system based on rotary-percussive ultrasonic drill (RPUD). The RPUD employs vibrations on two sides of one single piezoelectric stack to achieve rotary-percussive motion, which improves drilling efficiency. The RPUD’s percussive system is composed of a percussive horn, a free mass, and a drill tool. The percussive horn enlarges longitudinal vibration from piezoelectric stack and delivers the vibration to the drill tool through the free mass, which forms the percussive motion. Based on the theory of conservation of momentum and Newton’s impact law, collision process of the percussive system under no-load condition is analyzed to establish the collision model between the percussive horn, the free mass, and the drill tool. The collision model shows that free mass transfers high-frequency small-amplitude vibration of percussive horn into low-frequency large-amplitude vibration of drill tool through impact. As an important parameter of free mass, the greater the weight of the free mass, the higher the kinetic energy obtained by drill tool after collision. High-speed camera system and drilling experiments are employed to validate the inference results of collision model by using a prototype of the RPUD.

scholarly journals Analysis of Vibration Monitoring Data of Flexible Suspension Lifting Structure Based on Time-Varying Theory

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6586
Author(s):  
Qifeng Peng ◽  
Peng Xu ◽  
Hong Yuan ◽  
Haixia Ma ◽  
Jianghong Xue ◽  
...  
Keyword(s):  
Transverse Vibration ◽  
Longitudinal Vibration ◽  
Low Frequency ◽  
Elastic Interaction ◽  
Vibration Monitoring ◽  
Test Results ◽  
Longitudinal Vibrations ◽  
High Frequency Region ◽  
Power Spectral ◽  
Short Time

An elevator is a typical flexible lifting machine. In order to monitor the vibration of elevator structure, the vibration characteristics of an elevator with a traction ratio of 1:1 has been tested experimentally. Sensors were arranged on the platform frame, car roof, and hoist rope to test the vibrations of the elevator in both ascending and descending conditions. The transverse, longitudinal, and coupled transverse-longitudinal vibrations were compared and analyzed. Further, the short-time Fourier transform (STFT) method was used to examine the power spectral density (PSD) of the test results, and the main frequency distribution and influencing factors of the vibration of elevator components were investigated. The results revealed that the transverse and longitudinal vibrations of the platform frame were low-frequency vibrations, which was attributed to the elastic interaction between the platform frame and the car frame. The form and amplitude of longitudinal vibration of the car frame were basically consistent with those of the platform frame, but PSD of the transverse vibration had an obvious peak in the high-frequency region. The transverse and longitudinal vibration frequencies of the hoist rope were higher. Furthermore, the peak PSD value of transverse vibration of the hoist rope was 421 times larger than that of the car frame, so a small disturbance at the end of the rope could lead to a huge disturbance in the center of the rope. Overall, this study provides useful insights on designing an elevator monitoring sensor and relevant data processing.

Model reference adaptive LQT control for anti-jerk utilizing tire-road interaction characteristics

2020 ◽  
pp. 095440702097397
Author(s):  
Yunpeng Yue ◽  
Ying Huang ◽  
Donghao Hao ◽  
Guoming G Zhu
Keyword(s):  
Reference Model ◽  
Longitudinal Vibration ◽  
Equilibrium Points ◽  
Low Frequency ◽  
Linearization Method ◽  
Linear Quadratic ◽  
Slip Ratio ◽  
Road Surfaces ◽  
On The Road ◽  
Quadratic Tracking

Sudden vehicle propulsion torque change under tip-in/out maneuver often leads to low-frequency longitudinal vibration due to the flexibility in the half-shaft and tire slip, which greatly affects vehicle drivability. Note that the vibration frequency is between 1 and 10 Hz and is difficult to be absorbed by the vehicle mechanical system. To optimize the vehicle drivability under tip-in maneuver, an Adaptive Linear Quadratic Tracking (ALQT) anti-jerk traction controller is proposed in this paper. Based on the experimental data, a Carsim-Simulink co-simulation model is developed for assessing control performance. A control-oriented model, considering the nonlinear characteristics of the tire-road friction coefficient and slip ratio, is then proposed. A reference model with rigid axle is used to provide the equilibrium points and reference velocity trajectory. Jacobi linearization method is then used to linearize the model along the desired trajectory and a linear deviation model based on equilibrium points is obtained. Finally, the deviation compensation receding horizon LQT controller is designed along with the Kalman state estimation. The effectiveness of the designed controller is assessed via simulation studies under different road surfaces and compared with PID and LQR controllers. The LQT controller is able to track the desired velocity profile with minimum jerk while increasing road safety. Furthermore, the effect of LQT weighting coefficients under different road surfaces are discussed. Simulation results show that the ALQT controller is able to optimize vehicle drivability under different road surfaces and the weighting matrices shall be selected based on the road condition for optimal drivability.

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