Plan pick-up system.

摘要

1. Drawing acquisition system, of the type of those including a table (2) provided with a drawing sensor (5) formed from N photosensitive elements angularly juxtaposed in such a way as to form a closed curve, a state of the said sensor being defined by the state of the photosensitive elements, a means (8) of displacing the sensor in a plane parallel with the table according to two perpendicular axes, and a means (9) of storing and transmitting the position of the sensor and its state the said table receiving a drawing (4) to be acquired constituted from one or more connected drawings, the said system also including : - a means (10) of following a line of a drawing delivering, on seeing the sate of the sensor, signals to the means (8) of displacing the sensor in such a way as to centre the said sensor on the followed line, - a means of analysis (12) for detecting, on seeing he state of the sensor, the intersections of lines encountered by the sensor and of recognizing the said intersections, - a means of sampling (14) for storing, according to a predetermined criterion, the coordinates of points of the followed drawing lines, - a means of control (16) capable of carrying out successive displacements of the sensor in predetermined steps in the direction of the followed line, capable of succesively actuating, after each displacement of the sensor, the means (10) of line following, the means of analysis (12) and the means of sampling (14), the said means of control in addition receiving from the means of analysis the characteristics of the lines recognized at the intersections and being capable of commanding the sensor to successively follow all the lines of a connected drawing, means external to the system for displacing the sensor from one connected drawing to another connected drawing, the said system being characterized in that the means (10) of line following is capable, when two disconnected groups of photosensitive elements are off, of determining the angles (THETA1 , THETA2 ) between the radii coming from the centre of the sensor and passing through the middle of each of the said groups and a reference direction (Ox), of determining the slope (alpha) of the followed line and of commanding a displacement of the sensor, perpendicular to this slope, in order to centre it over the followed line, and the means of analysis (12) comparing the state of the sensor with typical configurations delivered by a means (18), in order to recognize the said intersections.