超声谐振式盲文点显胞元的挤压膜建模 及实验研究

Modeling and experiment of ultrasonic resonant Braille display cell’s squeeze film

  • 摘要: 目前传统的盲文书籍已经难以满足盲人的阅读需求,本文基于超声振动产生的挤压膜提出了一种超声谐振 式盲文点显胞元。理论推导了决定挤压膜气动力学特性的 Reynolds 方程,利用挤压膜的“活塞效应”得到了输出托 浮力的力学模型及近似解,利用搭建的实验平台开展了盲文点显胞元的振动特性测试和输出性能测试。结果表明: 该盲文点显胞元的谐振频率为 30.8 kHz,激励电压峰峰值在 130~200 Vpp 时,可以形成稳定且具备一定托浮能力的 挤压膜。理论计算值与实验实测数据基本吻合,实验中三种不同质量的试样可被托起 13.92~47.71 μm 的高度,盲 文点显胞元具备足够的输出性能。

     

    Abstract: At present, traditional Braille books have had difficulty meeting the needs of the blind, this paper proposes a new type of ultrasonic resonant Braille display cell based on the squeeze film generated by ultrasonic vibration. The Reynolds equation which de? termines the aerodynamic characteristics of the squeeze film is derived theoretically, the mechanical model and approximate solu? tion of the output buoyancy are obtained by using the “piston effect” of the squeeze film, the vibration characteristics and output performance test of Braille display cell were tested using the built experimental platform. The results show that the resonant fre? quency of the Braille display cell is 30.8 kHz, when the peak-to-peak value of the excitation voltage is 130 Vpp to 200 Vpp, a sta? ble squeeze film with certain buoyancy can be formed. The theoretical calculation results are basically consistent with the experi? mental results. In the experiment, three kinds of samples can be lifted from 13.92 μm to 47.71 μm, Braille display cell has suffi? cient output performance.

     

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