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压电式六维力传感器结构仿真及信号处理电路设计

Structure Simulation of Piezoelectric Six Axis Force Sensor and Design of Signal Processing Circuit

【作者】 罗勇

【导师】 刘京诚;

【作者基本信息】 重庆大学 , 仪器科学与技术, 2008, 硕士

【摘要】 在机器人传感器中,力传感器是最基本的一种,能够检测三维力和三维力矩的六维力传感器是机器人最不可或缺的重要传感器。虽然,对多维力传感器的研究已有40多年的历史,科研工作者在这方面也已经做了大量的科研工作,但就目前的各种方法主要还是通过设计不同的弹性体和改变电阻应变片的贴片位置等来设计多维力传感器,由于贴片工艺和弹性体加工精度等因素的影响,制造出来的传感器几乎都存在结构复杂、加工制造困难、体积大、动态响应特性差等缺点。为了解决目前六维力传感器的不足之处,本文研究了一种结构简单的直接输出型压电六维力传感器,该传感器具有体积小,质量轻,工作可靠,固有频率高,灵敏度和信噪比高,滞后小,且无需对输出信号进行解耦运算等优点。对该传感器的研究具有十分重要的研究意义和广阔的应用前景。本文首先介绍了压电传感器的工作原理,接着分析了各种压电材料的压电特性,选择石英作为传感器的转换元件材料;根据传感器的受力范围,设计了石英晶片的尺寸;根据传感器测量六维力(力矩)的需要,提出了传感器敏感元件的布局方案。整个六维力传感器通过两个四维力传感器组合构成,该结构具有很好的对称性,可以避免施加纯力的过程中附加力矩的干扰。论文运用三维有限元理论和ANSYS软件,针对设计的压电式六维力传感器,在ANSYS中建立了该传感器的模型。并运用ANSYS软件对六维力传感器进行了静力分析、电磁分析和模态分析。仿真结果表明,该传感器的结构设计合理,具有较好的线性度,高灵敏度,维间干扰较小,固有频率较高等特点。最后论文分析了压电传感器对测量电路的要求,选用电荷放大器作为压电传感器的处理电路,在分析电荷放大器的各功能模块的基础上,研制了电荷放大器电路。

【Abstract】 Force sensor is the most basic sensor in robot, and six axis force sensor that can measure three axis force and three axis moment is indispensable sensor in robot. Researchers have studied multi-axis force sensor for more than forty years and have gained many achievements. But at present and before, multi-axis sensors are designed by applying different elastomers and changing the position where resistance stain gauges stick on. Because of the influence of patch technics and elastomer processing precision, produced sensors almost have the shortcomings of complex structure, difficult manufacture, and large volume. Dynamic responses of these sensors are poor.To overcome these shortcomings, this paper studies piezoelectric sensor with direct output. The sensor has small volume, light mass, high reliability, high natural frequency, high sensitivity and signal-to-noise, little delay. It doesn’t need decoupling operation. It has great research significance and wide foreground to study this sensor.At first, principle of piezoelectric sensor is introduced in the paper. After compared many kinds of piezoelectric material, quartz is selected as the sensitive element material of sensor. The size of quartz wafer is decided by the measurement range of force. Arrangement of quartz wafer is designed to meet the requirement for measuring six axis force. The whole six axis force sensor is made up of two pieces of four axis force sensors. The structure is symmetric, which can avoid the interference of torque.In this paper, based on three-dimensional finite element theory, the model of the six axis piezoelectric sensor is built in ANSYS. Static analysis, electromagnetic analysis, and modal analysis of the sensor are done through the ANSYS software. The result of simulation shows that the sensor has good linearity, high sensitivity, little interference among each dimension, high natural frequency.At last, the requirement of charge amplifier is analyzed in the paper, and PCB of charge amplifier has been produced after studying circuit module.

  • 【网络出版投稿人】 重庆大学
  • 【网络出版年期】2009年 06期
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