Abstract: In automatic assembly apparatus operating under electronic vision control, features on components to be assembled must be recognized and located in position and orientation so that a gripper mechanism may be directed to one component to pick it up and move it into correct position and orientation relative to the other component for assembly. The invention provides a known parallel projection optical system 8, 9, at the location of each component which provides a plan view for an electronic camera 11 of the components 20, 22 at constant scale regardless of lateral or axial component movements. The grey-level picture of each component provided by the camera is thresholded into a binarized picture at a threshold level which selects a primary component feature 27 within a part of the camera field of view which is certain to contain this feature.

Abstract: A control valve having an actuating member supported within and between a closed end and a seat end of a housing, the actuating member having a fixed end connected to the close housing end and a free end connected to a movable valve body, the actuating member including an elongated piezoelectric element having a relatively low thermal coefficient of expansion. The housing is made from common, inexpensive materials having moderately higher thermal coefficient of expansion, and the actuating member includes a spacer having a high thermal coefficient of expansion, arranged between the closed housing end and the piezoelectric element. By proper dimensioning of the spacer and housing with respect to the piezoelectric element, temperature compensation may be achieved without the use of exotic materials.