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The biodynamic response of 14 subjects to sinusoidal dual-axis vibration in lateral and roll directions is studied. The root mean square of human response is detected by measuring the torque at the seat pan. The effects of phase difference, magnitude, and frequency on the biodynamic responses are investigated. The consistency between human responses to dual-axis and single-axis is studied. With increasing phase difference, human response is found to reach the maximum when the vibrations are anti-phase and then decrease to the minimum when they are in-phase. Besides, the dominance of the lateral excitation is confirmed in the dual-axis vibration. Finally, the principle of equivalence between lateral-roll dual-axis vibration and roll single-axis vibration is established. With the equivalence method, the biodynamic characteristics of the human body to multi-axis vibration are expected to be measured and represented with a much simpler test and dynamic model. Proposed equivalence uses one index to evaluate the compound discomfort caused by the roll and lateral vibration. Overestimation of discomfort due by summing the effects of them calculated separately can be avoided. After the equivalence, evaluation of discomfort and modelling of the human body can be carried out only in roll direction.
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http://dx.doi.org/10.1080/00140139.2022.2118375 | DOI Listing |
Front Neurorobot
May 2025
Robotics and Micro-systems Center, School of Mechanical and Electrical Engineering, Soochow University, Suzhou, China.
Introduction: Traditional positioning and pointing mechanisms often face limitations in simultaneously achieving high speed and high resolution, and their travel range is typically constrained. To overcome these challenges, we propose a novel positioning and pointing mechanism driven by piezoelectric ceramics in this study. This mechanism is capable of achieving both high speed and high resolution by using two driving principles: resonance and stick-slip.
View Article and Find Full Text PDFMicromirror technology is one of the current research hotspots. In this work, what we believe to be a novel electrostatic 2-DOF micromirror structure with double-biased torsional axes is proposed. By introducing internal resonance, synchronous motions of the two axes with a locked frequency ratio under a single driving force were achieved within a wide frequency range.
View Article and Find Full Text PDFRev Sci Instrum
August 2024
State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
In space optical applications, the piezoelectric-actuated fast steering mirror (FSM) is one of the pivotal components for high-precision beam capturing and trajectory tracking. The FSM is restrained in small-angle scanning applications due to the short actuation stroke of the incorporated piezoelectric materials. This study introduces a dual-axis sub-radian stroke FSM with a high ratio of output range to resolution and self-sensing capability, based on cascading structures for displacement amplification and flexible parts for feedback.
View Article and Find Full Text PDFSensors (Basel)
December 2022
National Engineering Research Center of Fiber Optic Sensing Technology and Networks, Wuhan University of Technology, Wuhan 430070, China.
In this paper, a dual-axis Fabry-Pérot (FP) accelerometer assembled on single optical fiber is proposed. The sensor is equipped with a special beam-splitting prism to split the light into two perpendicular directions (the X- and Y-axes); the prism surface coated with semi-permeable film and the reflective sheet on the corresponding Be-Cu vibration-sensitive spring form two sets of FP cavities of different sizes. When the Be-Cu spring with a proof mass (PM) is subjected to the vibration signal, the cavity length of the corresponding FP cavity is changed and the interference signal returns to the collimator through the original path of the prism.
View Article and Find Full Text PDFErgonomics
July 2023
School of Mechanical Engineering, Tianjin University, Tianjin, China.
The biodynamic response of 14 subjects to sinusoidal dual-axis vibration in lateral and roll directions is studied. The root mean square of human response is detected by measuring the torque at the seat pan. The effects of phase difference, magnitude, and frequency on the biodynamic responses are investigated.
View Article and Find Full Text PDF