Numerical Controller Oscillating Axis Speed Phase Control

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Solution Overview

Problem

Existing numerical controllers for grinding machines face challenges in maintaining precision at boundary points due to accumulation during acceleration and deceleration, and they are unable to efficiently change speeds in oscillating operations, leading to increased processing time.

Innovation Solution

A numerical controller that designates positions and reference speeds for an oscillating axis, calculates the current phase and speed, and adjusts the speed control to prevent accumulation and optimize processing time by changing the speed in optional sections within the oscillating operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If constant speed control is used in oscillating operation, then the control system is simple, but accumulation in moving amount occurs at boundary points during acceleration and deceleration, reducing precision

Engineering Contradiction:

Improveprecision at boundary pointVSAvoidspeed control complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements dynamic speed control by calculating and adjusting the speed command value based on the current phase of the oscillating axis. The speed varies continuously according to the phase angle, eliminating constant speed control and preventing accumulation errors at boundary points while maintaining system precision.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the speed parameter dynamically during oscillating operation. By modifying the speed command value according to the phase of the oscillating axis, the system adapts speed to operational requirements, preventing accumulation errors without requiring complex additional hardware.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If speed is changed in optional sections of oscillating operation, then processing time is reduced, but control accuracy may be affected

Engineering Contradiction:

Improveprocessing timeVSAvoidcontrol accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent calculates the phase of the oscillating axis in advance and uses this phase information to determine appropriate speed command values. By preparing speed adjustments based on predicted phase positions, the system optimizes processing time while maintaining control accuracy through proactive speed management.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent employs feedback by continuously monitoring the phase of the oscillating axis and adjusting the speed command value accordingly. This closed-loop approach ensures that speed changes in optional sections maintain control accuracy while achieving reduced processing time through optimized speed profiles.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS8195325B2Numerical controller having oscillating operation function capable of changing speed in optional section

Publication Date: 2012.06.05 FANUC LTD

AI summary

A machine tool has an oscillating axis that reciprocates in an optional region. A numerical controller that controls the machine tool designates positions of a lower dead point and a upper dead point when the oscillating axis of the machine tool reciprocates, and a reference speed during the oscillating operation when the oscillating axis reciprocates. The numerical controller then calculates, from the current position of the oscillating axis, a current phase in the case where one stroke of the oscillating axis is defined as one cycle, and calculates the speed of the oscillating axis at the current phase based upon the calculated current phase and the reference speed.