A probing control apparatus for use in aligning an object comprises: a mechanism having n-degrees of freedom and adapted for controlling the object; n pieces of actuators for actuating the mechanism; detecting means for detecting change in the output from the object in response to the operation of each...http://www.google.com/patents/US4884015?utm_source=gb-gplus-sharePatent US4884015 - Probing control method and apparatus for mechanism with multiple degrees of freedom
