Deformable sensor system

A deformable sensor system, comprising:

• a deformable sensor having a pressure-receiving surface being capable of receiving external force, and additionally undergoing elastic deformation by means of receiving said external force onto said pressure-receiving surface, and comprising an elastic material whose electric resistivity, when all types of elastic deformations including compression deformation and tensile deformation are caused therein respectively, increases monotonically as an elastic deformation variation in each of the elastic deformation increases;
• four or more electrodes being disposed on a peripheral rim of said pressure-receiving surface separately to each other;
• a power-source unit for supplying a current between paired electrodes being selected from out of said electrodes;
• a detecting unit being connected to paired electrodes being different from said paired electrodes to be connected to said power-source unit and being selected from out of said electrodes, thereby detecting a voltage that arises between the said paired electrodes being connected thereto;
• a connection switching unit for switching said paired electrodes, which are connected to said power-source unit, one after another, and for switching said paired electrodes, which are connected to said detecting unit, one after another;
• a sensitivity-matrix memory unit for storing a sensitivity matrix Sm,n,x,y, which has been computed in advance based on said voltage being detected from said detecting unit in the case of not applying said external force to said pressure-receiving surface and in the case of supplying a predetermined current from said power-source unit to said paired electrodes;
• an electric-resistivity variation computing unit for computing a variation δρ(x, y) of said deformable sensor's electric resistivity that minimizes an evaluation function J of Equation (1) while satisfying a condition of Equation (2) in the case of applying said external force to a digitized two-dimensional plane-coordinate position (x, y) in said pressure-receiving surface, based on each of said voltages' variations δV(m, n), which are detected by means of said detecting unit in the case where said paired electrodes being connected to each other are switched by means of said connection switching unit, and based on said sensitivity matrix Sm,n,x,y, which is stored in said sensitivity-matrix memory unit;
• and
• an external-force position computing unit for computing a position in said pressure-receiving surface, position which receives said external force, based on said electric-resistivity variation δρ(x, y) being computed by means of said electric-resistivity variation computing unit;
• wherein
• J=∥δV(m,n)−Sm,n,x,y·δρ(x,y)∥2 (1)
• δρ(x,y)≧0 (2)
• δV(m,n):
• Variation of Respective Voltages being Detected by means of Detecting Unit
• δρ(x,y):
• Variation of Electric Resistivity of Deformable Sensor
• Sm,n,x,y:
• Sensitivity Matrix Comprising Jacobian Matrix
• m:
• Suffix Designating Electrodes' Position to which Voltage is Applied by means of Power-Source Unit
• n:
• Suffix Designating Electrodes' Position at which Voltage is Detected by means of Detecting Unit
• x, y:
• Digitized Two-Dimensional Coordinate Position in Pressure-Receiving Surface.