CONFIGURATION OF TACTILE SENSING SYSTEM

This system uses conductive plasterer as a sensor, which has a property that its conductivity changes as a function of the pressure applied. Fig 1 shows the configuration of the system. The conductive elastomer is mounted on 8*8 force sensing sites for the measurement of pressure distribution on the object. These force sensing sites are connected through PC add on data acquisition card. Stepper motor is used to apply specific amount of pressure for the proper identification of the objects. Hardware for scanning the matrix and related signal conditioning is designed along with the stepper motor interface circuitry. Once the image of the object is acquired through the Tactile Sensing System, then it is further processed using Image Processing concepts for the proper identification and inferring other properties of the objects. Tactile data for the object identification is acquired using Row-Scanning technique. After the removal of noise from this tactile data, it passes to the different modules of the system for further processing.
TACTILE DATA PROCESSING

The main modules of this system are pre-processing, data acquisition, matrix representation, graphical representation, edge detection and moments calculations for generating a feature vector. Tactile image acquisition involves conversion of the pressure image into an array of numbers that can be manipulated by the computer. In this system, a tactile sensor is used to obtain the pressure data of the object and this data is further acquired with the help of data acquisition and data input/output card, which are interfaced with the computer. The pre-processing module involves in the removal of the noise, which is essential for acquiring the image of the object under consideration. The image is analyzed by a set of numerical features to remove redundancy from the data and reduce its dimensions. Invariant moments are calculated in this module, which are required by the next module to the artificial neural for the identification of the object independent to scale, rotation and position.

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