GB1319561A

GB1319561A - Automatic digitizing system

Info

Publication number: GB1319561A
Application number: GB2309371A
Authority: GB
Original assignee: INFORMATION DEV CORP
Current assignee: INFORMATION DEV CORP
Priority date: 1970-03-04
Filing date: 1971-04-19
Publication date: 1973-06-06
Also published as: FR2081697A3; DE2109921A1; FR2081697B3

Abstract

1319561 Programmed control of machine tools INFORMATION DEVELOPMENT CORP 19 April 1971 [4 March 1970] 23093/71 Heading G3N [Also in Division G1 and G4] A computer controlled electro-mechanical scanner for determing co-ordinates of a series of points on a 3-dimensional surface consists of a pressure sensitive probe controlling a probe driving servosystem, an incremental change in probe position in any one co-ordinate causing at that instant a computer reading of probe position in all three co-ordinates. As shown in Figs.2 and 9, which illustrate the apparatus for only one co-ordinate, the absolute position of the probe is given by the position of the probe itself, from a linearly variable differential transformer 26 feeding an A/D converter 27, and the position of the servomotor, from shaftposition encoder 52 and register 54, the two positions being combined in summer 56 and held in register 58. The position is displayed at 62 and fed to register 152 Fig.9, for comparison with the last read position held in register 150. The difference in the two registers (158) is compared with a standard increment fed into register 154 from the computer. Upon an incremental change in position in any co-ordinate the respective flipflop 164 is set to signal the computer over line 166 to read the registers 58 holding the probe position. If 164 has not been reset, indicating completion of reading, by the next increment, flip-flop 174 is set to stop the servo-motors. Register 150 is updated at each reading. The computer generates a punched tape for control of machine tools from the co-ordinate readings. The servosystem Fig.11 drives the probe motor with a signal from the probe 14 to maintain contact with the surface, with a speed signal from tachometer 150 and with a position signal from the computer 32 which is compared in counter 156 with the signal from the motor shaft-encoder 52 and converted to an analogue signal (159) before input to the motor amplifier 152. (For Figures see next page)