| 摘要 |
<p>1,235,555. Programmed control of machine tools. HOUDAILLE INDUSTRIES Inc. July 11, 1968 [July 12, 1967], No.33191/68. Heading G3N. A numerical positioning control system comprises a stored programme digital computer in on-line real-time programmed communications with a console, supplying numerical positioning command data in accordance with a stored programme, and a machine tool positioning means, which receives digital signals therefrom in accordance with the command data. As shown, a computer 603 has a first stored programme therein with which it interprets command input numerical positioning data, derived from a tape reader 600 through a tape reader interface 601, and feeds digital command signals to X and Y axes servo loops 622, 623. The servo loops, incorporating digital to analog converters independently function to drive the machine axes 605, 607 at a high speed towards the commanded positions. When the axes are within a predetermined distance of the end point, digital-to-analogue circuits, (not shown), progressively slow down the axes. When both axes are in the vicinity of the end point for a required time, null detector components, (not shown), signal the computer via a machine positioning interface 628. Other operations of the computer 603 are then held by a programme interrupt signal from the interface 628. The computer energizes an axis Hold circuit, (not shown), and reads the contents of the absolute position registers 609, 610. The stored programme then compensates for an error in the new position command. The computer then determines if a punch, tool change or other operation should be initiated before a new positioning cycle takes place. A further stored programme enables the generation of new positioning programmes from a console 602 contemperaneously with the machine operation. While the programme being generated is stored in the memory of the computer, any items thereof may be recalled to the console 602 for modification and checking. The operator can then signal the computer to enter the programme on a punched tape. The digital feedback components 112, 611 are photo-electric transducers and include preamplifiers supplying squarewave signals to the synchronizers 117, 608 which determines the sense of rotation of each transducer and supplies a clock pulse for each rotation of the transducer.</p> |
