Acceleration/deceleration control apparatus

Claim 1

An acceleration/deceleration control apparatus for controlling acceleration/deceleration of a controlled object when command data blocks are read successively from a machining program and the controlled object is driven to a predetermined position at a command velocity using servomotors, said apparatus comprising: pulse distributing means for setting interpolation data with regard to the controlled object and processing a current command data block of the command data blocks successively read from the machining program to distribute the interpolation data as distributed pulses to the servomotors; acceleration/deceleration setting means for setting an acceleration/deceleration control variable to accelerate or decelerate each of the servomotors; comparison means for comparing an actual velocity of the controlled object with the command velocity of a next command data block successively read from the machining program; and control means for controlling the pulse distribution, when the command velocity in the next command data block to be processed net by said pulse distributing means is less than the velocity command in the current command data block presently being processed by said pulse distributing means, to stop the pulse distribution by said pulse distributing means until an actual velocity of the controlled object decelerated based on the acceleration/deceleration control variable is less than the command velocity of the next command data block.

Claim 7

A method for eliminating deviation in machining trajectory f a machine tool, having an actual velocity, controlled by a numerical control unit using a machining program, having m command data blocks, where m is an integer, each command data block including a position command and a velocity command, said method comprising the steps of: (a) inputting the (n-1) th command data block from the machining program where (1≦n≦m); (b) executing the (n-1) th command data block by issuing pulse distribution pulses to the machine tool in order to control movement of the machine tool; (c) inputting the n th command data block from the machining program during said executing step (b); (d) determining if the magnitude of the n th command velocity in the n th command data block is less than the (n-1) th command velocity in the (n-1) th command data block; (e) delaying execution of the (n-1) th command data block until the actual velocity is less than the (n-1) th command velocity if said determining in step (d) is affirmative; and (f) executing the (n-1) th command data block.

Claim 8

A method for eliminating deviation in machining trajectory f a machine tool, having an actual velocity, controlled by a numerical control unit using a machining program, having m command data blocks, where m is an integer, each command data block including a position command and a velocity command, said method comprising the steps of: (a) inputting the (n-1) th command data block from the machining program where (1≦n≦m); (b) executing the (n-1) th command data block by issuing pulse distribution pulses to the machine tool in order to control movement of the machine tool; (c) inputting the n th command data block from the machining program during said executing step (b); (d) determining if the magnitude of the n th command velocity in the n th command data block is less than the (n-1) th command velocity in the (n-1) th command data block; (e) delaying execution of the (n-1) th command data block until the actual velocity is less than the (n-1) th command velocity if said determining in step (d) is affirmative; and (f) executing the (n-1) th command data block.