Tactile Sensor and Tactile Sensor Application Apparatus

• US 20080271933A1
• Filed: 09/05/2005
• Published: 11/06/2008
• Est. Priority Date: 09/05/2005
• Status: Active Grant

• Current Assignee: Ewsystem Company Limited
• Original Assignee: Ewsystem Company Limited
• Inventors: Morimoto, Kenichi
• Granted Patent: US 8,300,018 B2
• Time in Patent Office: Days
• US Class Current: 178/18.05
• CPC Class Codes: A61B 5/447 specially adapted for aiding the prevention of ulcer or pressure sore development, i.e. before the ulcer or sore has developed
• CPC Class Codes: B25J 13/084 Tactile sensors in general G01L5/16, G01L5/22
• CPC Class Codes: G01L 5/162 of piezoresistors
• CPC Class Codes: G01L 5/228 using tactile array force sensors
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A tactile sensor for detecting a variation in pressing real-time. The tactile sensor is simple in structure, detects a variation in pressing by using reduced wires, has increased reliability and reduced cost, and can obtain information accurately. A sheet has, along its surface, resistors arranged in an X direction and Y direction, has a resistor in Z direction corresponding to the thickness direction of the sheet, and has a pressure sensitive resistor sheet (4) whose resistance in the Z direction varies according to pressing in the thickness direction. At least a pair of electrodes (9, 10, 11, 12) is placed in the periphery of the pressure sensitive sheet (4), and the electrodes conduct a current to at least either of the resistor in the X direction or the resistor in the Y direction. Also, at least a pair of conductors (5, 6) for conducting a current to the resistor in the Z direction is provided on the surface of the pressure sensitive sheet (4).

Claims

1. A tactile sensor, comprising

a pressure sensitive resistance sheet (4) that has resistance in an X direction and in a Y direction along a sheet plane and that has resistance in a Z direction coinciding with a thickness direction of the sheet and varies the resistance in the Z direction in response to a pressing in the thickness direction,

in a circumferential part of the pressure sensitive resistance sheet (4), at least one pair of electrode parts (9, 10, 11 and 12) for passing a current in at least one of the resistance in the X direction and the resistance in the Y direction is provided, and on a surface of the pressure sensitive resistance sheet (4), at least one pair of electric conductors (5, 6) for passing a current in the resistance in the Z direction is provided.

2. The tactile sensor according to claim 1, characterized in that,

when a current is made to flow from any one of the electrode parts (9, 10, 11 and 12) and the electric conductors (5, 6) and the current is taken out from the remaining electrode parts (9,10, 11 and 12) or the electric conductors (5,6), a contact pressure and a contact position of at least either of a contact position in the X direction or a contact position in the Y direction are configured to be obtained from a combination of voltages (V9, V10, V11 and V12) of the at least one pair of electrode parts (9,10,11 and 12) and voltages (V5, V6) of the at least one pair of the electric conductors (5,6).

3. The tactile sensor according to claim 2, characterized in that,

when a current is made to flow from any one of the electrode parts (9, 10, 11 and 12) and the electric conductors (5, 6) and the current is taken out from the remaining electrode parts (9, 10, 11 and 12) or the electric conductors (5, 6), a voltage difference of the voltages (V9, V10, V11 and V12) of the at least one pair of the electrode parts (9, 10, 11 and 12) between before contacting the tactile sensor and at the time of contacting the tactile sensor is corrected to a value corresponding to the obtained contact pressure and contact position, and thereby at least one contact length of a contact length in the X direction and a contact length in the Y direction is configured to be obtained.

5. The tactile sensor according to claim 1, characterized in that

the pressure sensitive resistance sheet (4) is the tactile sensor, made up of a film having a surface resistance of a few kilo ohms to a few tens of mega ohms.

6. A tactile sensor application apparatus, comprising:

a controlled apparatus (1) in which the tactile sensor (3) according to claim 1 is installed;

a power supply (15) for generating a potential gradient in the pressure sensitive resistance sheet (4); and

an A/D converter (25) for converting an output voltage of the electrode parts (9, 10, 11 and 12) and the pair of the electric conductors (5, 6) into a digital value;

characterized by further comprising a control unit (27) for controlling the controlled apparatus (1) that inputs a digital signal from the A/D converter (25), obtains at least two of a contact pressure to the tactile sensor (3), a contact position, and a contact length in the X direction and/or the Y direction of the tactile sensor (3), and controls the controlled apparatus (1) based on these obtained contact pressure, contact position and contact length.

4. A tactile sensor, comprising

a pressure sensitive resistance sheet (4) that is a sheet having resistance in a direction along the sheet plane and has resistance in a thickness direction varies in response to a pressing in the thickness direction,

characterized in that

a current is made to flow in the pressure sensitive resistance sheet (4) in order to obtain at least two of a contact pressure to the pressure sensitive resistance sheet (4), a contact position thereof, and a contact length thereof, and

the pressure sensitive resistance sheet (4) is made up of a film having a surface resistance of a few kilo ohms to a few tens of mega ohms.