US 4,635,206 AGranted

Method and apparatus for oscillating a tool carried by a manipulator

AssigneeCincinnati Milacron Inc.

InventorsMadhukar Bhatia, Brian J. Resnick

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Abstract

A method and apparatus are provided for providing for controlled oscillation of a tool centerpoint associated with a function element carried by manipulator simultaneously with motion of a workpiece feature relative to a predetermined location. The tool centerpoint describes a predetermined pattern relative to the workpiece feature as a result of the combined motion. Tool centerpoint oscillation occurs in an oscillation path between two extremes determined by pattern parameters defining pattern amplitude measured with respect to a pattern longitudinal axis. The direction of the oscillation path is defined by input signals representing angles measured relative to a rectangular coordinate system used for defining the predetermined location. The rate of tool centerpoint motion is defined by an input signal representing velocity.

Claims10

Dependent claims

A method for oscillating a tool centerpoint in a line through a predetermined location, the tool centerpoint being associated with a function element carried by a manipulator having movable members and actuators for effecting motion of the members, a predetermined pattern of motion being defined by input signals representing pattern parameters measured relative to a pattern longitudinal axis and including pattern pitch and pattern amplitude, the line of oscillation having a direction defined by further input signals, the rate of motion of the tool centerpoint being defined by an input signal representing velocity, and the duration of oscillation being determined in response to input signals representing functions selectably defining a predetermined period of time and an indefinite period terminating on occurrence of a predetermined event, the method comprising the steps of:

(a) moving a workpiece feature relative to the predetermined location in response to the input signal representing a function;
(b) periodically producing iteration interval signals, each iteration interval signal representing a period of time during which an increment of motion of the tool centerpoint is to be effected by the manipulator;
(c) producing an accumulated pattern distance signal in response to the input signals representing velocity and pattern pitch and the iteration interval signal, the accumulated pattern distance signal representing a distance along the pattern longitudinal axis;
(d) producing an excursion amplitude signal in response to the input signals representing pattern parameters and the accumulated pattern distance signal, the excursion amplitude signal representing the pattern amplitude corresponding to the accumulated pattern distance;
(e) effecting motion of the tool centerpoint on the line of oscillation to a point spaced from the predetermined location by the distance defined by the excursion amplitude signal;
(f) iterating steps (b) through (e) for the period defined by the input signal representing a function to oscillate the tool centerpoint in the oscillation line thereby producing relative motion of the tool centerpoint and the workpiece feature in accordance with the predetermined pattern.

3 more elements

An apparatus for oscillating a tool centerpoint in a line through a predetermined location, the tool centerpoint being associated with a function element carried by a manipulator having movable members and actuators for effecting motion of the members, the oscillation occurring simultaneously with motion of a workpiece feature relative to the predetermined location, a predetermined pattern of motion being defined by input signals representing pattern parameters measured relative to a pattern longitudinal axis and including pattern pitch and pattern amplitude, the line of oscillation having a direction defined by further input signals, the rate of motion of the tool centerpoint being defined by an input signal representing velocity, and the duration of oscillation being determined in response to input signals representing functions selectably defining a predetermined period of time and an indefinite period terminating on occurrence of a predetermined event, the apparatus comprising:

(a) means responsive to the input signal representing a function for moving the workpiece feature relative to the predetermined location;
(b) means for periodically producing iteration interval signals during the period determined by the input signal representing a function, each iteration interval signal representing a period of time during which an increment of motion of the tool centerpoint is to be effected by the manipulator;
(c) means responsive to the iteration interval signal and the input signals representing velocity for producing an accumulated pattern distance signal representing a distance along the pattern longitudinal axis;
(d) means responsive to the accumulated pattern distance signal and the input signals representing pattern parameters for producing an excursion amplitude signal representing the pattern amplitude associated with the pattern longitudinal distance represented by the accumulated pattern distance signal;
(e) means responsive to the excursion amplitude signal for producing servo command signals representing increments of motion of the machine members for effecting motion of the tool centerpoint on the oscillation line to a point spaced from the predetermined location by the distance defined by the excursion amplitude signal;
and
(f) means for applying the servo command signals to the servo mechanism circuit to oscillate the tool centerpoint in the oscillation line thereby producing relative motion of the tool centerpoint and the workpiece feature in accordance with the predetermined pattern.

4 more elements

Dependencies are inferred from the claim text.