ACTIVE TACTILE SENSOR APPARATUS AND METHOD

摘要

A tactile sensing apparatus having a piezoelectric energizing layer with a plurality of conductors disposed on one surface of a piezoelectric material and a plurality of conductors disposed on the opposite surface of the piezoelectric material, the plurality of conductors having electrical connections connected to electrical energizing means. An electrical insulating layer is disposed adjacent the piezoelectric energizing layer. A second piezoelectric sensing layer is disposed adjacent the insulating layer, and has conducting surfaces disposed on opposite surfaces thereof. The conductors in the piezoelectric energizing layer provide N x M energizing areas with N + M electrical connections to the energizing layer. Further apparatus may include an oscillator, an optional amplifier and a switching means or multiplexer for the input signal. The apparatus may optionally have more than one piezoelectric energizing layer as well as more than one piezoelectric sensing layer. PVF2 is the preferred piezoelectric material. An optional base material and protective layer may be used. A method of operating the tactile sensor includes providing a variable frequency electrical signal at a frequency and amplitude adapted to energize the energizing areas. The signal is switched to the conductors to energize selected energizing areas of the energizing layer in a predetermined sequence. The signal generated in the sensing layer that varies in frequency and amplitude in response to an object in contact with the tactile sensor is processed for frequency and amplitude information to determine the characteristics of the object such as shape, force or weight.