Adaptive Control Device Injection Molding Frequency Response
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Solution Overview
Problem
Existing adaptive control methods for injection molding machines face challenges in automatically adjusting control parameters in response to changes in the controlled target, leading to potential degradation in responsiveness and instability, especially when dealing with unknown or unidentified targets.
Innovation Solution
An adaptive control device and method that incorporates a parallel feed-forward compensator with an identification section to estimate the frequency response characteristic of the controlled target and an adjustment section to automatically adjust the compensation value by setting the PFC frequency and gain, using predetermined coefficients based on the estimated characteristics, ensuring optimal adaptive control without manual re-adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the compensation value from the parallel feed-forward compensator is increased to improve stability, then stability is improved, but responsiveness degrades
Solution Approach 1:
The patent applies dynamics by making the PFC parameters (gain and frequency) variable rather than fixed. The adjustment section dynamically modifies these parameters based on frequency response characteristics detected from the controlled target, allowing the system to adapt between stability and responsiveness based on actual operating conditions rather than relying on fixed conservative settings
Solution Approach 2:
The patent implements parameter changes by automatically adjusting the PFC gain and frequency parameters based on detected frequency response characteristics. The adjustment section modifies these parameters according to the actual behavior of the controlled target, enabling optimal balance between stability and responsiveness without manual intervention or excessive compensation values
2Measurement precision
If manual adjustment of PFC parameters is performed to achieve optimal control, then control precision is improved, but ease of operation deteriorates due to required expertise
Solution Approach 1:
The patent implements self-service by enabling the control system to automatically adjust its own PFC parameters without external intervention. The adjustment section continuously monitors frequency response characteristics and autonomously modifies the PFC gain and frequency to achieve optimal control performance, eliminating the need for operator expertise in manual tuning
Solution Approach 2:
The patent applies feedback by using the detected frequency response characteristics of the controlled target to automatically adjust the PFC parameters. The system continuously monitors the actual behavior of the controlled target and uses this feedback information to optimize the compensation parameters, achieving high control precision without manual intervention
3Ease of operation
If pre-stored gains are used for automatic adjustment, then ease of operation is improved, but adaptability deteriorates when the controlled target changes
Solution Approach 1:
The patent applies dynamics by transitioning from static pre-stored gains to dynamic parameter adjustment. The adjustment section continuously adapts the PFC parameters based on real-time frequency response characteristics of the controlled target, enabling the system to automatically adjust to target changes while maintaining ease of operation through automated control
4Device complexity
If model parameters are directly used as control parameters, then device complexity is reduced, but reliability deteriorates due to modeling errors
Solution Approach 1:
The patent introduces an intermediary approach by using frequency response characteristics as a bridge between the controlled target and the PFC parameters. Rather than directly using model parameters, the system detects actual frequency response characteristics and uses these as an intermediary to adjust the PFC gain and frequency, reducing the impact of modeling errors while maintaining system simplicity
Data Source
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AI summary
Provided are an adaptive control device and adaptive control method, and a control device of an injection molding machine, which allow optimal adaptive control to be performed automatically and easily, while preventing a degradation of responsiveness. The adaptive control device is configured to perform feedback control in such a manner that an operation value (u) is output based on a command value (r) and a feedback value (ya) which is a sum of a controlled value (y) output from a controlled target (2) and a compensation value (yf) output from a parallel feed-forward compensator (4); wherein the parallel feed-forward compensator (4) includes: an identification section (6) which sequentially estimates a frequency response characteristic of the controlled target (2) and an adjustment section (7) which adjusts the compensation value (yf) based on the estimated frequency response characteristic.