Controller for multiple-axis machine
First Claim
1. Apparatus to control the movement of a tool relative to a workpiece along each one of a plurality of axes in accordance with a predetermined sequence of intended speeds and positions, said movement along each axis being produced by an electromechanical actuator, said apparatus comprisinga digital pulse generator arranged to generate a train of periodic digital output pulses and to deliver said pulse train directly to said actuator, anda digital controller arranged to receive command signals that represent said sequence of intended speeds and positions, and to generate corresponding digital control signals for said digital pulse generator to control the widths of said digital output pulses in said pulse train so that electrical energy is carried in said pulse train at rates which will cause said actuator to tend to produce said sequence of intended speeds and positions,said digital controller being further arranged to approximate said intended positions as a hypothetical series of connected linear steps of movement, and said intended speeds as hypothetical rates at which said linear steps occur, and to base said digital control signals in part on said steps and said rates.
3 Assignments
0 Petitions
Accused Products
Abstract
Movement of a tool relative to a workpiece along each one of a plurality of axes is controlled by digitally providing a train of digital pulses to an electromechanical actuator and by digitally modulating the pulse widths (without an intervening conversion to analog form) so that electrical energy is carried in the pulse train at rates which will cause the actuator to tend to produce an intended sequence of speeds and positions.
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Citations
31 Claims
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1. Apparatus to control the movement of a tool relative to a workpiece along each one of a plurality of axes in accordance with a predetermined sequence of intended speeds and positions, said movement along each axis being produced by an electromechanical actuator, said apparatus comprising
a digital pulse generator arranged to generate a train of periodic digital output pulses and to deliver said pulse train directly to said actuator, and a digital controller arranged to receive command signals that represent said sequence of intended speeds and positions, and to generate corresponding digital control signals for said digital pulse generator to control the widths of said digital output pulses in said pulse train so that electrical energy is carried in said pulse train at rates which will cause said actuator to tend to produce said sequence of intended speeds and positions, said digital controller being further arranged to approximate said intended positions as a hypothetical series of connected linear steps of movement, and said intended speeds as hypothetical rates at which said linear steps occur, and to base said digital control signals in part on said steps and said rates.
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30. Apparatus to control the movement of a tool relative to a workpiece along each one of a plurality of axes in accordance with a predetermined sequence of intended speeds and positions, said movement along each axis being produced by an electromechanical actuator, said apparatus comprising
a digital pulse generator arranged to generate a train of periodic digital output pulses and to deliver said pulse train directly to said actuator, and a digital controller arranged to receive command signals that represent said sequence of intended speeds and positions, and to generate corresponding digital control signals for said digital pulse generator to control the widths of said digital output pulses in said pulse train so that electrical energy is carried in said pulse train at rates which will cause said actuator to tend to produce said sequence of intended speeds and positions, said digital pulse generator being further arranged to be capable of delivering no output pulses and hence no energy to said actuator, said digital controller comprising a shut-off control which causes said digital generator to deliver no output pulses during periods of signal interference.
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31. A method of controlling the movement of a tool relative to a workpiece along each one of a plurality of axes in accordance with a predetermined sequence of intended speeds and positions, said movement along each axis being produced by an electromechanical actuator, said method comprising
generating a train of periodic digital output pulses and delivering said pulse train directly to said actuator, approximating said intended positions as a hypothetical series of connected linear steps of movement, and said intended speeds as hypothetical rates at which said linear steps occur, and basing said digital control signals in part on said steps and said rates, and in response to command signals that represent said sequence of intended speeds and positions, generating corresponding digital control signals for said digital pulse generator to control the widths of said digital output pulses in said pulse train so that electrical energy is carried in said pulse train at rates which will cause said actuator to tend to produce said sequence of intended speeds and positions.
Specification