Browse Prior Art Database

High Density Tactile Sensor with One Resistance Wire

IP.com Disclosure Number: IPCOM000086158D
Original Publication Date: 1976-Jul-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 4 page(s) / 97K

Publishing Venue

IBM

Related People

Wang, SSM: AUTHOR

Abstract

Fig. 1 shows a pair of manipulator fingers 10, 11 holding an object 12. The gripping force pushes a protective skin 13 and a conducting cloth 14 contacting a resistance wire 15. Wire 15 bends back and forth as shown in Fig. 3 to cover the entire area under cloth 14. At a position where object 12 held by finger 11 does not touch the gripping surface, cloth 14 is separated from wire 15 by a pressurized air film in space 16.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 4

High Density Tactile Sensor with One Resistance Wire

Fig. 1 shows a pair of manipulator fingers 10, 11 holding an object 12. The gripping force pushes a protective skin 13 and a conducting cloth 14 contacting a resistance wire 15. Wire 15 bends back and forth as shown in Fig. 3 to cover the entire area under cloth 14. At a position where object 12 held by finger 11 does not touch the gripping surface, cloth 14 is separated from wire 15 by a pressurized air film in space 16.

Cloth 14 is connected to a power supply 17 and maintains the same voltage level as the power supply, e.g., 10 volts DC. Wire 15 is supported by and pneumatically sealed with a high-strength insulator 18, e.g., a phenolic.

Referring to Fig. 3, a groove 19 in insulator 18 lies beneath wire 15 and has the exact same pattern as wire 15. A conducting strip 20 lies on the base of groove 19. The hollow channel 22 formed by wire 15, insulator 18, and strip 20 is filled with a nonconducting fluid except for one small droplet 21 of conducting fluid, e.g., mercury. The nonconducting fluid in channel 22 and droplet 21 move along channel 22 at a constant speed and/or a sinusodial oscillation.

These motions can be controlled by two actuators 23, 24, mounted at the end of the finger system by conduits 26 and 25, as shown in Fig.
1.

Referring to Fig. 2, a potentiometer 27 measures the position of the piston of actuator 24. Since nonconducting fluid is incompressible, knowing the position of the piston of the actuator 24, the position of droplet 21 is computed from the ratio of the piston area and the groove cross-section area. Both potentiometer 27 and strip 20 are connected to computer 28. Based upon an equivalent circuit diagram as shown in Fig. 4B and flow chart as shown in Fig. 5, computer 28 locates the contacting points between object 12 and fingers 10, 11.

In Fig. 4, when fingers 10, 11 hold object 12, cloth 14 contacts wire 15 at line segments C(1)C(2), C(3)C(4), C(5)C(6), etc. When droplet 21 touches any segment, such as segment C(1)C(2), the voltage difference between points A and D is zero, and the...