Method and apparatus for numerical control

US3941987A · kind A · utility

Assignee

• Danly Machine Corporation · US

Inventor

• Carl E. Tack, Jr. · Glen Ellyn, US

Key dates

• Filing date: Apr 30, 1975
• Grant date: Mar 2, 1976
• Expiry date: Apr 30, 1995

Classification

• Technology area (CPC G): Physics
• CPC primary: G05B2219/43158
• WIPO field: Control
• WIPO sector: Instruments

Abstract

Method and apparatus for numerical control to produce contouring by simultaneous coordinated motions along two or more axes, characterized by the creation of desired velocity signals supplied as the primary inputs to velocity servos coupled to drive a member relatively along the respective axes. Although capable of practice by and susceptible of embodiment in other apparatus, a digital computer is physically organized and conditioned by a master program, and associated with an adjustable interrupt clock which measures off successive time periods .DELTA.T, so as to supply a changeable velocity command number signal to each servo proportional to the distance per .DELTA.T through which motion along the associated axis is to occur. This velocity command number is algebraically added to a theoretical position number to signal dynamically during each period .DELTA.T the axis position at which the member should reside; and the latter number is used with a dynamically signaled actual position number to re-compute and signal during each period the position error. The position errors are used as a trimming or adjusting term in the signals applied to the respective axis servos. When the signa…