电气工程与自动化 外文翻译 外文文献 英文文献 一种低成本智能式电容位置传感器_精品.doc
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文献、资料题目:A Low-Cost, Smart Capacitive
Position Sensor
文献、资料来源:IEEE TRANSACTIONS ON
INSTRUMENT AND
MEASUREMENT
文献、资料发表(出版)日期:1992.12
院 (部): 信息与电气工程学院
专 业: 电气工程与自动化
外文文献:
A Low-Cost, Smart Capacitive Position Sensor
Abstract
A new high-performance, low-cost, capacitive position-measuring system is described. By using a highly linear oscillator, shielding and a three-signal approach, most of the errors are eliminated. The accuracy amounts to 1 μm over a 1 mm range. Since the output of the oscillator can directly be connected to a microcontroller, an A/D converter is not needed.
I. INTRODUCTION
This paper describes a novel high-performance, low-cost, capacitive displacement measuring system featuring:
1 mm measuring range,
1 μm accuracy,
0.1 s total measuring time.
Translated to the capacitive domain, the specifications correspond to:
a possible range of 1 pF;
only 50 fF of this range is used for the displacement transducer;
50 aF absolute capacitance-measuring inaccuracy.
Meijer and Schrier [l] and more recently Van Drecht,Meijer, and De Jong [2] have proposed a displacement-measuring system, using a PSD (Position Sensitive Detector) as sensing element. Some disadvantages of using a PSD are the higher costs and the higher power consumption of the PSD and LED (Light-Emitting Diode) as compared to the capacitive sensor elements described in this paper.
The signal processor uses the concepts presented in [2],but is adopted for the use of capacitive elements. By the extensive use of shielding, guarding and smart A/D conversion,the system is able to combine a high accuracy with a very low cost-price. The transducer produces three-period-modulated signals which can be selected and directly read out by a microcontroller. The microcontroller,in return, calculates the displacement and can send this value to a host computer (Fig. 1) or a display or drive an actuator.
Fig. 1. Block diagram of the system
Fig. 2. Perspective and dimensions of the e
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