Optical attenuator movement detection system

• US 5,184,009 A
• Filed: 04/06/1990
• Issued: 02/02/1993
• Est. Priority Date: 04/10/1989
• Status: Expired due to Fees

• Current Assignee: Raymond E. Wright, Scott M. Wright
• Original Assignee: Raymond E. Wright, Scott M. Wright
• Inventors: Wright, Scott M., Wright, Raymond E.
• Primary Examiner(s): Nelms, David C.
• Assistant Examiner(s): LE, QUE TAN
• Application Number:
  US07/505,563
• Time in Patent Office: 1,033 Days
• Field of Search: 250/227.11, 250/227.24, 250/221, 250/231 R
• US Class Current: 250/227.11
• CPC Class Codes: G02B 6/264 with optical elements between opposed fibre ends which perform a function other than beam splitting having lens focusing means G02B6/32; utilising prism or grating G02B6/34
• CPC Class Codes: G02B 6/4202 for coupling an active element with fibres without intermediate optical elements, e.g. fibres with plane ends, fibres with shaped ends, bundles
• CPC Class Codes: G05B 19/427 Teaching successive positions by tracking the position of a joystick or handle to control the positioning servo of the tool head, master-slave control G05B19/423 takes precedence
• CPC Class Codes: G05B 2219/35464 Glove, movement of fingers
• CPC Class Codes: G05B 2219/36454 Master slave, director agent, operator replication
• CPC Class Codes: G06F 3/014 Hand-worn input/output arrangements, e.g. data gloves

Abstract

An optical attenuation measurement system is provided for obtaining signals proportional to movement of a system to which it is attached. The measurement system includes a light source positioned within a length of conduit in which the light emitted will produce multiple reflections. A fiber optic cable is slidably disposed within the conduit to transmit the radiation emitted from the light source gathered thereby. The relative displacement of the fiber optic cable to the light source produces a signal as a function of this displacement which is converted into electrical signals by a light detecting element at the opposite end of the cable. The system is particularly useful to form an interactive device for control of a remote intelligent machine, robot or the like. For example, the system may be used on an operator'"'"'s hand to detect movement of the hand and fingers for controlling a robotic hand which will mimic the operator'"'"'s hand movements.

Claims

1. An optical detection system comprising:

light emitting means positioned in a first conduit so as to emit light into said first conduit,

light detecting means positioned in said first conduit adapted to receive light emitted into said first conduit by said light emitting means,

wherein the relative longitudinal distance that said light emitted into said first conduit travels between said light emitting means and said light detecting means is varied within said conduit in proportion to a variable to be detected.

2. An optical detection system as in claim 1, further comprising:

at least one light transmission means having first and second ends with said first end position in said first conduit to receive light emitted by said light emitting means,

said light detecting means being movable within said first conduit relative to said second end of said light transmission means, wherein said movement of said light detecting means varies the distance said light travels within said first conduit, and

said first conduit has an inner surface which has been treated so as to produce uniform reflections of light which will linearize the output of the system with variation of said relative longitudinal distance light travels within said first conduit upon movement of said light detecting means therein.

3. An optical detection system as in claim 2, wherein,

said treatment constitutes forming disconformities on said inner surface which will uniformly diffuse the light incident upon said surface.

4. An optical detection system as in claim 3, wherein,

said first conduit is made from a reflective metal material and said treatment of said inner reflective surface comprises oxidation of this surface.

5. An optical detection system as in claim 1, further comprising:

a second conduit which is adapted to be slidably engaged in said first conduit and has said light detecting means associated therewith.

6. An optical detection system as in claim 5, wherein,

said first and second conduits have a hexagonal cross-section with said second conduit being dimensioned to fit within said first conduit with close tolerance, wherein said hexagonal cross-section maintains relative linear and rotational alignment of said light detecting means relative to said light emitting means.

7. An optical detection system as in claim 5, wherein,

said first conduit is secured to a system, the movement of which is to be measured,

said second conduit is secured to said system at another location thereon such that movement of said system results in relative movement between said first and second conduits along with relative movement between said light emitting means and said light detecting means positioned within said first and second conduits respectively.

8. An optical detection system as in claim 7, wherein,

said system is a finger of human operator, and said conduit is secured adjacent the knuckle of said finger at the rotational axis of said knuckle with said second conduit being secured at a point toward the wrist of said human operator so as to measure abduction/adduction movements of said finger.

9. An optical detection system as in claim 1, wherein,

relative movement between said light emitting means and said light detecting means results in changing the length of a gap formed between said light detecting means and said light emitting means thereby varying the amount of light reaching said light detecting means from said light emitting means as a function of the variable to be measured.

10. An optical detection system as in claim 5 wherein,

said second conduit has an extended length adapted to accommodate the entire length of travel of said light detecting means along with said second conduit so as to form a rigidified structure.

11. An optical detection system as in claim 1 further comprising:

an outer housing means having first and second portions adapted to be slidably engaged with one another wherein said first portion houses said light emitting means and said second portion is associated with said light detecting means,

bias means acting on said first and second portions of said outer housing member so as to maintain an initial biased position therebetween when no external forces are applied to said first or second portions of said outer housing member.

12. An optical detection system as in claim 1, wherein,

said light emitting means is a length of fiber optic cable having first and second ends wherein a light source is positioned relative to said first end to emit light into said fiber optic cable and said second end is disposed within said first conduit so as to emit the light propagated therethrough into said first conduit.

13. An optical detection system as in claim 12, wherein,

said second end of said length of fiber optic cable is provided with a light conditioning means to provide desired optical characteristics to the light emitted from said second end of said length of fiber optic cable.

14. An optical detection system as in claim 1, wherein,

said detection system is mechanically tuned by introducing at least a predetermined offset between said light detecting means and said light emitting means positioned within said first conduit.

15. An optical detection system as in claim 1, wherein,

said detection system is tuned by varying the intensity of light emitted by said light emitting means to introduce a controlled non-linearity into the output response of said optical detection system.

16. An optical detection system as in claim 1, further comprising:

an optical control system for processing signals received from said light detecting means to develop control signals proportional to a variable to be measured, wherein said device is electrically tuned by varying the intensity of light emitted by said light emitting means so as to introduce the controlled nonlinearity into the output response to cancel any inherent non-linearity introduced by said light detecting means or said optical control system.

22. An optical detection system as in claim 1, wherein,

said light detecting means is associated with at least one light transmission means having first and second ends with said first end movably positioned in said first conduit to receive light emitted by said light emitting means and said second end associated with said light detecting means.

17. An optical detection system comprising:

a light emitting means,

a first conduit in which said light emitting means is positioned to emit light therein,

a second conduit adapted to be slidably received in said first conduit,

a light transmission means positioned in said second conduit so as to have a first end slidably positioned in said first conduit to receive light emitted by said light emitting means,

a light detecting means relative to a second end of said light transmission means to receive light propagated through said light transmission means,

wherein said second conduit has a minimum length to accommodate all slidable motion of said light transmission means within said first conduit so as to form a rigid system wherein the relative distance between said light emitting means and said first end of said light transmission means varies to yield an indication of a variable to be detected.

18. An optical detection system comprising:

a light emitting means positioned in a first conduit so as to emit light into said first conduit,

at least one light transmission means having first and second ends wherein at least said first end is positioned within said first conduit to receive light emitted by said light emitting means,

at least one light detecting means positioned relative to said second end of said at least one light transmission means adapted to receive light propagated through said light transmission means,

wherein the relative distance between said light emitting means and said first end of said light transmission means varies to yield an indication of the variable to be detected.

19. An optical detection system as in claim 18, further comprising:

first and second light transmission means having first and second ends respectively wherein said first ends are positioned within said first conduit on opposed sides of said light emitting means to receive light emitted by said light emitting means,

said light emitting means and said first ends being movableable relative to one another in said first conduit,

first and second light detecting means positioned relative to said second ends of said first and second light transmission means adapted to receive light propagated through said first and second light transmission means, wherein relative movement between said light emitting means and said first ends of said first and second light transmission means will vary the output response of said first and second light detecting means to form an optical potentiometer.

20. An optical detection system as in claim 19, wherein,

said first conduit having said light emitting means is slidable in an outer housing member wherein said first and second light transmission means are fixed relative to said outer housing member such that slidable movement of said first conduit will vary the relative position of said light emitting means to said first ends of said first and second light transmission means.

21. An optical detection system as in claim 18, wherein,

said light emitting means comprises a length of fiber optic cable having first and second ends wherein said first end is positioned relative to a light source such that light is emitted into said fiber optic cable and said second end disposed within said first conduit so as to emit the light propagated through said fiber optic cable into said first conduit.