Inspection apparatus and methods for precision vibration-isolation tabletops
Apparatus and methods to automatically inspect precision tabletops used for vibration isolation are described. An inspection head having an imaging device and/or perturbing device can be positioned automatically at a plurality of locations over a precision tabletop. The inspection head can further include a distance sensor that can be used to determine a flatness of a portion or all of a surface of the precision tabletop. The inspection head may further include marking apparatus to automatically mark non-compliant features formed on the precision tabletop.
1. A vibration-isolation inspection system comprising:
an inspection head having an imaging array and a perturbing device that imparts mechanical energy to a precision vibration-isolation tabletop; and
a system controller configured to control motion of the inspection head with respect to a surface of the precision vibration-isolation tabletop, wherein the system controller is configured to produce data indicating vibration-damping characteristics at a plurality of locations on the surface of the precision vibration-isolation tabletop.
2. The vibration-isolation inspection system of claim 1 , wherein the inspection head further includes a distance sensor configured to determine a distance between the surface of the precision vibration-isolation tabletop and a location on the inspection head.
3. The vibration-isolation inspection system of claim 1 , wherein the inspection head further includes marking apparatus arranged to impose a mark on a surface of the precision vibration-isolation tabletop.
4. The vibration-isolation inspection system of claim 1 , further comprising positioning apparatus configured to position the inspection head at a plurality of locations over the precision vibration-isolation tabletop.
5. The vibration-isolation inspection system of claim 4 , wherein the positioning apparatus comprises a robotic arm.
6. The vibration-isolation inspection system of claim 1 , further comprising apparatus to produce an optical reference plane over the surface of the precision vibration-isolation tabletop.
7. The vibration-isolation inspection system of claim 1 , wherein the system controller is configured to read a design file and determine locations of features machined on the surface of the precision vibration-isolation tabletop to be inspected.
8. The vibration-isolation inspection system of claim 1 , wherein the system controller is configured to produce data indicating a flatness of the surface of the precision vibration-isolation tabletop.
9. The vibration-isolation inspection system of claim 1 , wherein the system controller is configured to generate compliance data indicating a displacement of the surface as a function of frequency for at least a range of frequencies below 100 Hz for each location at which the perturbing device imparts the mechanical energy to the precision vibration-isolation tabletop.
10. A method of inspecting a precision vibration-isolation tabletop, the method comprising:
automatically positioning an inspection head at a first location over the precision vibration-isolation tabletop;
obtaining an image of a portion of a surface of the precision vibration-isolation tabletop;
automatically imparting an impulse to the surface with an impact hammer;
receiving sensor information indicating an effect of the impulse on the surface;
automatically positioning the inspection head at a plurality of locations over the precision vibration-isolation tabletop;
measuring a plurality of distances to the surface from the inspection head at the plurality of locations over the precision vibration-isolation tabletop; and
determining a flatness of the surface based on the plurality of distances.
11. The method of claim 10 , further comprising:
generating, from the sensor information, compliance data indicating a displacement of the surface as a function of frequency for at least a range of frequencies below 100 Hz for the first location.
12. The method of claim 10 , further comprising providing information relating to the flatness of the surface to a user.
13. The method of claim 10 , further comprising, at a plurality of locations:
automatically imparting an impulse to the surface with the impact hammer;
receiving sensor information indicating an effect of the impulse on the surface; and
providing information relating to vibration-damping characteristics at the plurality of locations to a user.
14. The method of claim 10 , further comprising deploying a vibration sensor from the inspection head onto the surface.
15. The method of claim 10 , further comprising imparting a mark on the portion of the surface based on an image of a mounting feature in the portion of the surface.
16. The method of claim 10 , further comprising reading a design file to determine a location at which to position the inspection head, wherein the design file includes information about mounting features formed in the surface.
17. The method of claim 10 , further comprising determining an accuracy of a location of a mounting feature in the surface based on the image.
18. The method of claim 17 , further comprising providing information relating to the accuracy of the location of one or more mounting features in the surface to a user.
19. A method of inspecting a precision vibration-isolation tabletop, the method comprising:
automatically positioning an inspection head at a plurality of locations over the precision vibration-isolation tabletop;
obtaining information about physical characteristics of the precision vibration-isolation tabletop at the plurality of locations;
providing the information to a user of the precision vibration-isolation tabletop measuring a distance between a location on a surface of the precision vibration-isolation tabletop and the inspection head at the plurality of locations; and
referencing the measured distance to an optical reference plane.
20. The method of claim 19 , wherein the physical characteristics include flatness of the surface of the precision vibration-isolation tabletop.
21. The method of claim 19 , wherein the physical characteristics include vibration-damping characteristics of the precision vibration-isolation tabletop.
22. The method of claim 19 , further comprising imparting an impulse to the surface of the precision vibration-isolation tabletop at the plurality of locations.
23. The method of claim 19 , further comprising:
imparting an impulse to the surface of the precision vibration-isolation tabletop at a first location;
receiving sensor information indicating an effect of the impulse on the surface; and
generating, from the sensor information, compliance data indicating a displacement of the surface as a function of frequency for at least a range of frequencies below 100 Hz for the first location.