Shockwave probe

• US 4,326,155 A
• Filed: 06/03/1980
• Issued: 04/20/1982
• Est. Priority Date: 06/03/1980
• Status: Expired due to Term

• Current Assignee: Cleveland Motion Controls, Inc. (Lincoln Electric Holdings Incorporated)
• Original Assignee: Automation Sensors, Inc.
• Inventors: Griebeler, Elmer L.
• Primary Examiner(s): Truhe, J. V.
• Assistant Examiner(s): Indyk, Eugene S.
• Application Number:
  US06/155,944
• Time in Patent Office: 686 Days
• Field of Search: 318/576, 318/577, 318/640, 318/645, 318/638, 367/906, 367/119, 367/127, 367/160, 367/161, 367/163, 367/180, 367/151, 367/95, 367/96, 367/97, 367/98, 367/103, 73/587, 73/596, 73/597, 73/602, 73/620
• US Class Current: 318/576
• CPC Class Codes: B23Q 35/127 using non-mechanical sensing
• CPC Class Codes: B25J 19/026 Acoustical sensing devices
• CPC Class Codes: Y10S 367/906 Airborne shock-wave detection

Abstract

Probe method and means are disclosed for guiding and positioning a robot-actuated tool, such as a gripper or a welding head, through at least one transceiver for generating and sensing focused shockwaves, the probe being associated with the tool for relative movement with respect to the object or objects being sensed, without physically contacting the same.

Claims

1. In a control system for a tool-positioning robot,

a work-sensing probe that senses the locus of work to be performed, including the loci of a continuum of such work, without physically contacting the work, comprising

means for generating a focused shockwave,

means for receiving the reflection of a focused shockwave,

means for differentiating the time/pressure parameters of the original shockwave from those of its reflection,

and means for translating the observed parametric differences into an electric signal within the control system to direct the robot to position the tool at the sensed locus of the work.

2. The invention of claim 1, in which the means for generating a shockwave includes a piezoelectric component.

3. The invention of claim 1, in which the means for receiving the reflection of a shockwave includes a piezoelectric component.

4. The invention of claim 2, in which the piezoelectric component is a piezo-bender disc.

5. The invention of claim 3, in which the piezoelectric component is a piezo-bender disc.

6. The invention of claim 1, in which the shockwave generating- and reflection-receiving means are combined as a transceiver.

7. The invention of claim 6, in which the transceiver includes a piezoelectric component.

8. The invention of claim 7, in which the piezoelectric component is a piezo-bender disc.

9. The invention of claim 1, in which the differentiating means and translating means includes step-recognizer means for noting the pressure immediately before and after the shockwave to provide a threshold voltage intermediately of the noted pressure values, and voltage comparator means responsive to said threshold voltage.

10. The invention of claim 9, further including means for comparing the characteristics of the received reflection of a shockwave with those of a preselected reference standard.

11. The invention of claim 1, in which the translating means includes a time-to-voltage translator that converts the time between shockwave generation and the reception of its reflection into a voltage value.

12. The invention of claim 11, in which the voltage value represents the distance between the tool and the sensed locus of the work.

13. The invention of claim 1, in which the means for generating a shockwave has means for focusing the shockwave associated with it.

14. The invention of claim 2, including means for focusing a generated shockwave.

15. The invention of claim 4, including means for focusing a generated shockwave.

16. The invention of claim 6, in which the transceiver is associated with means for focusing a generated shockwave.

17. The invention of claim 15, including a statically inert mass for mounting the piezo-bender disc at its center, said mass having annular clearance spaces for the disc freely to oscillate in response to impressed voltage, a radiating surface activated by the disc to generate focused shockwaves in the ambient atmosphere, and means for damping and absorbing residual and extraneous vibrations that are not components of a generated shockwave.

18. The invention of claim 17, in which the radiating surface produces a spherical shockwave that radiates in converging relation to a remote focal point.

19. The method of sensing the presence and location of an object, without physically contacting it, that includes generating a focused shockwave, beaming the shockwave with the object at the focus of the shockwave so that a sufficient amount of the energy of the shockwave is reflected from it, receiving the reflection, and translating the parameters of time, distance, and pressure difference of the shockwave and its reflection into an electric signal.

20. The method of claim 19, which includes effecting relative positioning between the sensed object and a work zone in response to the electric signal.