Noncontact Material Identification and Distance Measurement Using Effective Capacitance With CdS Cells
We propose a novel noncontact sensing method for material identification and for detection of the distance between the sensor and the surface of a material by using its electrical and optical properties. In the proposed method, capacitance between the terminals of a pair of CdS cells, called the effective capacitance, is measured, and several capacitance values are obtained by changing the emission strength of the light emitting diode, thus changing the resistance value of the CdS cells. From these values, it is possible to identify the materials and to detect the distance between the CdS cells and the material. In this paper, we compare four kinds of effective capacitance measurement methods using a pair of CdS cells and describe the proposed measurement method. In addition, this paper discusses the measurement accuracy of effective capacitance values in the proposed method and demonstrates its ability to identify six material samples-clear, white, and black acrylic, clear vinyl chloride, brown bakelite, and aluminum-and to detect the distance between the CdS cells and the material.
A proposal of optical and electrical measurement method for tactile sensor using phototransistor
We propose a new tactile sensing method for simultaneous measurement of the indentation on the sensor surface and the material properties of test objects by single sensor. The proposed sensor consists of electrodes and phototransistors with light emitting diode (LED). In the proposed method, the admittance between electrodes and phototransistors is measured while changing of light emission by the LED. The electrical property of the object is measured by the admittance between electrodes, and the indentation on the sensor surface measured by the admittance between phototransistors. In the experiment, discrimination of four kinds of materials (Acrylic, POM, Glass and Aluminium) and detection of the indentation on the sensor surface were demonstrated. The proposed sensor may be applicable for a tactile sensor in robots.
Handbook of Concrete Engineering
Handbook of concrete engineering , Handbook of concrete engineering , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی