| 摘要 |
1307017 Controlling movement LICENTIA PATENT - VERWALTUNGS GmbH 26 March 1970 [29 March 1969] 14889/70 Heading G4H In a system for controlling an output quantity such as the movement of a spot on a cathode-ray tube in accordance with digital data, the full digital range is divided into a plurality of subranges each having the same group of digital signals and a computer calculates the required output quantity by extrapolation, to distinguish between the various sub-ranges, thus reconstructing the full range of the input. The signal generating unit comprises a ball bearing 2 upon which two friction wheels 4 and 5 bear. The friction wheels drive coded discs 6X and 6Y associated with contact elements CX and CY. Depression of switch 7 activates the unit. Movement along the X and Y axes is encoded in Gray code by units 6X, CX and 6Y, CY respectively. The coding discs are characterized by being divided into a number of zones each zone being identical, the code values changing regularly throughout each zone. Thus the digital information derived from the coding disc merely indicates the position of the signal generating unit within a zone and not in which zone the unit lies. The position indicated by the coding discs 6X or 6Y and the pick-ups CX or CY is transferred on receipt of a transfer pulse from unit TG, to a shift register 14. In the interval between transfer pulses this information is transferred in serial form from the shift register 14 to a computer R. The computer determines which zone the signal generating unit lies in by calculating an extrapolated position on the basis of data referring to previously recorded points, and calculating the velocity and acceleration of the signal generating unit. The observed position is compared with the extrapolated position in order to determine the particular zone in which the signal generator lies. The full digital representation of the position of the signal generating unit is stored in the computer and fed via a shift register to a digital to analogue converter and thence to the cathode-ray tube display. |
