Robotic skin

• US 4,694,231 A
• Filed: 04/18/1986
• Issued: 09/15/1987
• Est. Priority Date: 04/18/1986
• Status: Expired due to Fees

• Current Assignee: Mecanotron Corporation
• Original Assignee: Mecanotron Corporation
• Inventors: Alvite', Joseph G.
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/853,637
• Time in Patent Office: 515 Days
• Field of Search: 318/568, 318/646, 73/862.04, 73/862.68, 73/432 T, 310/338, 310/800, 901/33, 901/46, 338/47, 338/99, 338/101, 338/114, 338/100, 338/112, 338/104, 364/513, 364/557, 364/558
• US Class Current: 318/568.11
• CPC Class Codes: B25J 13/084 Tactile sensors in general G01L5/16, G01L5/22
• CPC Class Codes: B25J 19/063 working only upon contact with an outside object
• CPC Class Codes: G01L 5/228 using tactile array force sensors
• CPC Class Codes: H01C 10/06 adjustable by short-circuiting different amounts of the resistive element
• CPC Class Codes: H01H 13/702 with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
• CPC Class Codes: H01H 13/785 characterised by the material of the contacts, e.g. conductive polymers
• CPC Class Codes: H01H 2201/026 non precious
• CPC Class Codes: H01H 2201/036 Variable resistance
• CPC Class Codes: H01H 2231/04 Robot
• CPC Class Codes: H01H 2239/06 Temperature sensitive

Abstract

A multi-layered tactile sensing skin is provided for a robotic arm or the like. The skin includes adjacent layers of electrically insulative film having opposed contiguous surfaces. An electrically conductive carbon based compound is applied uniformly to one of the surfaces, while the other surface is selectively coated with silver oxide to form a series of pairs of first and second electrically conductive regions separated from one another by a dielectric gap. The carbon based conductor bridges the gap betwen the conductive regions in each pair, permitting flow of electrical current between the regions. The current flow increases with an increase in pressure over the interface between the layers of film, and the amperage increase can be utilized to trigger a signal to the robot power supply, to decelerate, stop or reverse arm movement.

Claims

1. A tactile sensing skin for a movable member including:

a first flexible dielectric film forming a first insulative layer mounted with respect to the outside surface of a movable member, and having a first surface facing outwardly away from said member;

a second flexible and dielectric film forming a second insulative layer adjacent said first insulative layer, and having a second surface facing said first surface;

a carbon base electrically conductive compound substantially uniformly applied to one of said first and second surfaces;

an electrically conductive metallic compound selectively applied to the other of said surfaces, whereby said metallic compound and carbon base conductive compounds are contiguous over the interface between said first and second films, said metallic compound being selectively applied to form a plurality of discrete pairs of first and second electrically conductive regions and a dielectric gap between said conductive regions of each pair;

a means for establishing a substantially constant potential difference between the first conductive region and second conductive region in each pair;

a first matting of resilient fiber forming a first flexible layer attached to the outwardly facing surface of said second film;

an elastically deformable outer layer attached to the outwardly facing surface of said first flexible layer; and

a control means responsive to changes in the amount of electrical current flowing between said first and second electrically conductive regions, for controlling travel of said member.

2. The tactile sensing skin of claim 1 further including:

a second matting of a resilient fiber forming a second flexible layer adjacent said outside surface of said movable member, said first film being attached to the outwardly facing surface of said second matting.

3. The tactile sensing skin of claim 2 wherein:

said means for establishing a substantially constant potential includes a first conductive path in electrical communication with each of said first electrically conductive regions, and a second conductive path in electrical communication with each of said second electrically conductive regions, and means for providing a positive voltage level in said first conductive path.

4. The tactile sensing skin of claim 2 wherein:

said first and second flexible dielectric films comprise a single sheet of polyester film.

5. The tactile sensing skin of claim 1 wherein:

said conductive metallic compound comprises silver oxide.

6. The tactile sensing skin of claim 1 wherein:

each said gap is formed in an irregular path to increase its length relative to the size of said regions.

7. The tacile sensing skin of claim 1 wherein:

each said first conductive region, second conductive region and said gap are arranged in a spiral pattern.

8. The tactile sensing skin of claim 1 wherein:

said dielectric films, first matting and outer layer overlie substantially all of said member in surrounding relation thereto.