US 4,538,233 AGranted

Apparatus and method for oscillatory motion control

AssigneeCincinnati Milacron Inc.

InventorsBrian J. Resnick, Elena R. Messina, Madhukar Bhatia, John G. Holmes

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Abstract

An apparatus and method are provided for controlling the motion of a point associated with a function element carried by a machine. The motion describes an oscillatory pattern in a selectable plane through a path between two positions defined by input signals. The oscillatory motion pattern defines cyclic excursions about the path. Motion is effected by iteratively interpolating intermediate positions along the path, computing incremental excursion amplitudes associated with the intermediate position displacements, calculating coordinates of the intermediate position excursions and producing machine actuator control signals to move the machine members to advance the point from its position along the pattern to an intermediate position.

Claims12

Dependent claims

Method for controlling the motion of a point associated with a function element carried by a machine, the machine having a plurality of movable members and actuators for effecting motion of the function element, the controlled motion describing an oscillatory pattern in a selectable plane through a linear path between two positions, the positions being defined by position input signals representing position coordinates relative to a predetermined coordinate system, the oscillatory pattern defining excursions about the path, the oscillatory pattern being defined by oscillatory pattern parameter input signals, the selectable plane orientation being defined by selectable plane input signals, and the point velocity being defined by a velocity input signal, the method comprising the steps of:

(a) producing an incremental distance signal in response to the position input signals and the velocity input signal, the incremental distance signal representing an increment of displacement defining an intermediate position along the linear path;
(b) producing an incremental pattern amplitude signal in response to the incremental distance signal and the pattern parameter input signals, the incremental pattern amplitude signal representing the amplitude of an excursion described by the oscillatory pattern at the intermediate position;
(c) producing increment coordinate signals in respone to the incremental distance signal, the incremental amplitude signal, and the selectable plane input signals, the increment coordinate signals representing coordinates with respect to the predetermined coordinate system of an intermediate position displaced from the path by the incremental excursion amplitude;
(d) producing actuator control signals in response to the increment coordinate signals, the actuator control signals representing machine member displacements between the position of the point and the position defined by the increment coordinate signals;
(e) applying the actuator control signals to the actuators to effect motion of the point to the intermediate position defined by the increment coordinate;
and
(f) iterating steps (a) through (e) to move the point along the oscillatory pattern between the two positions.

4 more elements

Apparatus for controlling the motion of a point associated with a function element carried by a machine having a plurality of movable members and actuators for effecting motion of the function element, the controlled motion describing an oscillatory pattern in a selectable plane through a linear path between two positions defined with respect to a predetermined coordinate system, the oscillatory pattern defining excursions about the path, the oscillatory pattern being defined by oscillatory pattern parameter input signals, the selectable plane orientation being defined by selectable plane input signals, the positions being defined by position input signals and the point velocity being defined by a velocity input signal, the apparatus comprising:

(a) means responsive to the position input signals and the velocity input signal for iteratively producing incremental distance signals, each incremental distance signal representing an increment of displacement defining an intermediate position along the linear path;
(b) means responsive to the incremental distance signals and the oscillatory pattern parameter input signals for producing incremental pattern amplitude signals, each incremental pattern amplitude signal representing the amplitude of an excursion from the path described by the oscillatory pattern at an intermediate position;
(c) means responsive to the incremental distance signals, the incremental pattern amplitude signals and the selectable plane input signals for producing increment coordinate signals representing coordinates with respect to the predetermined coordinate system of an intermediate position displaced from the path the amount of the incremental pattern amplitude;
and
(d) means responsive to the incremental coordinate signals for producing actuator control signals representing actuator displacements between the position of the point and the displaced intermediate position, the actuator control signals effecting motion of the machine members to move the point along the pattern.

2 more elements

Dependencies are inferred from the claim text.