TEMPERATURE PROFILE DETERMINATION

摘要

Apparatus for determining the temperature profile of the surface being sprayed or otherwise treated, the apparatus comprising four electric arc spray guns (1) spraying molten steel. The guns (1) are connected to a six-axis industrial robot (2) which is adapted to move them over the surface of the ceramic substrate.(3). The metal deposited by the spray builds up a metal shell referred to as the sprayform. The temperature profile of the sprayform surface (3) is recorded periodically by a thermal imaging camera (4) positioned directly above the surface (3). When the field of view of the camera (4) is not obscured by the robot (2), the arc spray guns (1) or their cables (5), the thermal image of the whole sprayform surface (3) can be recorded. However, when the arc spray guns (1), their cables (5) and/or the robot (2) are positioned between the thermal camera (4) and the sprayform surface (3), at least part of sprayform surface (3) is obscured relative to the camera's field of view, with the result that large areas of the resultant thermal image may not be representative of the temperature of the sprayform surface (3). The apparatus includes a pruning filter for receiving each pixel of an image captured by the camera (4) and for applying at least a lower temperature limit to it so as to reject or disregard any pixels determined to have a temperature less than the lower temperature limit. The apparatus may also comprise storage means for storing a master image or array comprising temperature information relating to each of a plurality of pixels intended to be representative of an unobscured image of the surface, and means for updating the master image when the camera (4) captures a new thermal image of the surface by replacing the stored temperature information with updated temperature information obtained from the new thermal image for each of the pixels not rejected or disregarded by the filter means. Alternatively, or in addition, the apparatus may include a Kalman filter or the like which may be used to predict the temperature profile of the surface using the pixels not rejected or disregarded by the pruning filter.