Servo Learning Control with Dynamic Reference Axis Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional learning control using the angle synchronization method cannot be applied to machines that require changing the reference axis based on machining conditions, such as during workpiece setup and machining in machine tools.
Innovation Solution
A servo control apparatus that includes a position detection unit, a position error calculation unit, a reference axis position acquisition unit, a reference axis selection unit, and a learning control unit, which selects an appropriate reference axis based on machining conditions to perform learning control using the angle synchronization method, ensuring effective synchronization between the reference axis and synchronizing axes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the reference axis is changed according to machining conditions, then the adaptability of the learning control system is improved, but the complexity of the control system increases
Solution Approach 1:
The reference axis is dynamically selected based on machining conditions rather than being fixed. The control system automatically determines which axis serves as the reference axis during different machining phases (setup vs. machining operations), allowing the system to adapt to varying operational requirements without manual reconfiguration
Solution Approach 2:
The learning control system is designed to function with any of the multiple axes serving as the reference axis. The same learning control apparatus can handle different machining conditions by selecting different reference axes, making the system universal rather than requiring separate control systems for different operational modes
2Device complexity
If learning control is performed with a fixed reference axis, then the control system complexity is reduced, but the machining precision deteriorates when machining conditions change
Solution Approach 1:
The reference axis selection is dynamically adjusted based on the current machining condition. During setup operations, one axis may serve as the reference, while during actual machining operations, a different axis becomes the reference. This dynamic adaptation ensures that learning control is always performed relative to the most appropriate reference axis for the current operation, maintaining high machining precision
3Productivity
If the reference axis is switched between setup step and machining step, then the productivity is improved, but the reliability of learning control deteriorates
Solution Approach 1:
The machining process is segmented into distinct phases (setup step and machining step), with each phase having its own appropriate reference axis. The learning control system is segmented to perform separate learning operations for each phase, ensuring that learning data is not contaminated by operations from different phases. This segmentation maintains reliability while enabling productivity improvements through efficient use of multiple axes
Solution Approach 2:
The control system incorporates feedback mechanisms that monitor the current machining condition and automatically determine the appropriate reference axis. This feedback ensures that learning control is reliably performed with the correct reference axis selected, preventing errors that would occur from using an inappropriate reference axis during specific machining operations
Data Source
AI summary
A servo control apparatus for a machine that performs machining by causing a plurality of synchronizing axes to operate cooperatively in synchronized relationship with a reference axis, the servo control apparatus comprising: a position detection unit for detecting at least one of the position of the servo motor and the position of a driven body; a position error calculation unit for calculating an error between the position command and the position detected by the position detection unit; a reference axis position acquisition unit for acquiring the positions of a plurality of reference axes; a reference axis selection unit for selecting one reference axis based on a machining condition of the driven body from among the plurality of reference axes whose positions have been acquired; and a learning control unit for performing learning control using an angle synchronization method, based on the error and the position of the selected reference axis.