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Limited mobility severely impacts the quality of life of persons with lower-limb amputations. Therefore, it is imperative to develop proper rehabilitation techniques to prevent falls and injuries. A vibrotactile device was developed as a training tool to enhance the rehabilitation of persons with recent lower-limb amputations. Stimuli provided by the device trains the user to sense discrete perturbations...
A vibration controller based on wavelet neural network (WNN) is designed for jacket-type offshore platforms with time delay. The offshore platform is regarded as a single-degree-of-freedom (SDOF) system while wave forces are irregular disturbances, and we can rebuild them in the context of Morison equation and wave theory. To reduce the vibration, a WNN vibration controller is designed based on a...
This paper investigates the influence of converter-fed operation on magnetic forces and radial vibration in a hydrogenerator. Flux density distribution is computed using time-stepping finite element (FE) analysis and used to calculate force density distribution based on Maxwell stress tensor. Both temporal and spatial characteristics of selected flux density and force density waves are studied. Important...
This paper deals with induction machines bearing failures detection and diagnosis using vibration and temperature signals. It proposes the use of a new Classical Mechanics-inspired Optimization (CMO) metaheuristic for data clustering. To ensure failure detection, transitions from a state to another is analyzed in order to form a transitional model between system states generated by the clustering...
There are BBots (BristleBots) consist of a single and double vibration motor design. A single-actuated robot agent is more preferable due to its lower cost and energy consumption. Some studies reporting and modeling the linear motion single-actuated BBots are present in the literature. On the other hand, few of them included an explanation on its rotational motion. In this study, the planar motion...
In this paper, one fiber Bragg grating (FBG) vibration sensor is proposed and the application of weak signal processing based on Duffing oscillator model in optical fiber vibration sensors is studied. Frequency response and amplitude sensitivity experiments are all carried out to verify the characteristics of this FBG vibration sensor. By calculating the maximum Lyapunov exponent, these experiment...
This paper proposes a sensorless chatter detection method for a ball screw drive system used in milling, by introducing the mechanical energy factor (MEF). The MEF is an indicator for detecting self-excited chatter, based on the power factor theory used in electric systems, and monitors the phase difference between dynamic cutting force and displacement. By monitoring the MEF, the self-excited chatter...
Chatter vibration highly limits the accuracy and the material removal rate of numerical control (NC) machining operations. In this paper, an adaptive spindle speed selection method, based on an analysis using the semi-discretization method, is proposed to avoid and minimize chatter vibration in high-precision NC machining. Moreover, the proposed method is robust to modeling uncertainty and changing...
In this paper, the research of the dynamics for the constant force polishing robot system as the goal, through the establishment of the dynamics equations for the end of the robot polishing, a modal analysis of the end of the robot is analyzed. It is obtained its static characteristic and vibration characteristics by the analysis results and verified the meeting requirements of the stiffness and the...
Study of electron transport in nanopillar transistor at 300K shows that elastic vibration is an intrinsic behavior of the device. The frequency observed in the drain-source current is found to agree with the charging frequency. Given a quantum dot of size 10×10×9nm3, the maximum displacement is estimated to be 0.3nm. Once the displacement diminishes to zero, single-electron tunnel becomes the dominating...
We describe a design for an “audio display”, a loudspeaker that employs the bending vibrations of a panel, such as flat-panel television screen or projection surface, to render localized sound sources anywhere on the surface of the panel. The method employs a two-dimensional Fourier series reconstruction of the desired panel spatial vibration profile, and an array of force actuators affixed to the...
To predict the vibration displacement distributed on a vibrating surface, an r order Non-equidistant Grey Model (r-NGM) is proposed in this paper. This model is built by accumulating the initial discrete non-equidistant vibration displacement set with the r order Accumulated Generating Operation (r-AGO). The r-NGM is applied to a vibrating surface of a shaker to displacement prediction. The experimental...
In this paper, the force analysis of the blade roller of the tiny cultivator is described firstly. The static analysis of the blade is carried out by using the Simulation plug of SolidWorks, and the data of von mises stress, resultant displacement, equivalent strain and safety factor of the blade are obtained. Then the modal analysis of the blade roller is carried out, and the data of the top ten...
The circuit breaker is an important part of control and protection in the power system. Mechanical failure is the main fault of circuit breakers, and the loosening of fasteners is one of the typical mechanical faults. The self-loosening of bolted joints is closely related to the vibration, especially transverse vibration. There is strong vibration while the circuit breakers are opened and closed....
Unwanted residual vibration in dynamic system always causes many problems in industrial manufacturing. For instance, it is difficult for a crane to transport a heavy cargo to a specified location safely, quickly and accurately in the case of oscillation. In this paper, the crane system is simplified as a rail trolley hoisting system where the payload is a rod, and an input shaping method is investigated...
Based on the lumped parameter theory of piezoelectric transducer, the mathematical relationship between mutual radiation impedance and surface vibration velocity distribution of the array element is established, and then the simulation experiments were carried out for a 5×5 planar array. The simulation results show that the influence of amplitude and phase caused by mutual radiation impedance presents...
In practice, the lift that a propeller produces is composed of theoretical value and fluctuation, which results in vibration in aircraft. This paper will analyze the effect of the fluctuation on the quadcopter. In order to reduce the vibration caused by the fluctuation, an improved Additive-State-Decomposition-Based (ASDB) dynamic inversion stabilized controller is proposed. To show its effectiveness,...
This paper presents a MEMS based electrochemical seismic sensor with force-balanced negative feedback where the bandwidth of the proposed device was extended from 7–20 Hz to 0.1–50 Hz. The quantified sensitivity of 3227 V/ (m/s) was 161.4 times greater than the commercial moving-coil seismic sensor in the low frequency domain. The proposed seismic sensor may be widely used as a promising seismic detecting...
Sensitivity is an important index of the performance of micro-machined gyroscope, and enhancing sensitivity is an effective way to improve the performance of gyroscope. In this paper, a new type of vibration structure to enhance the sensitivity of butterfly micro-machined gyroscope was proposed. By using dry etching processing, the vibration structure can obtain a rectangle vibration beam rather than...
We report a unique MEMS resonant force sensor design that provides both reduced motional resistance and greatly enhanced strain gauge factor to target operation under ambient conditions. The proposed device has been realized in an Aluminum Nitride (AlN) on Silicon (Si) process, where the piezoelectric-AlN transducers are uniquely decoupled from a force sensitive triple beam tuning fork (TBTF) resonator...
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