Two-Degree-of-Freedom PID Tuning for Faster Settling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing two-degree-of-freedom PID control techniques for temperature or motor control systems suffer from increased settling time and overshooting due to excessive filtering, which hinders effective target value tracking.
Innovation Solution
A control device that dynamically sets filter coefficients α and β using the target value, initial value, proportional band, and integral time, along with system gain, to improve stability and reduce overshooting by calculating an internal target value for enhanced PID control operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If filter coefficients are increased to suppress overshooting, then stability improves, but settling time extends
Solution Approach 1:
The patent dynamically adjusts filter coefficients based on system state and operating conditions rather than using fixed values. This allows the system to optimize the balance between stability and response speed by changing filter parameters adaptively, suppressing overshooting when needed while maintaining fast settling time when conditions allow.
Solution Approach 2:
The filter coefficients are made dynamic rather than static, allowing the system to adapt its filtering strength based on real-time conditions. This dynamic adjustment enables the system to achieve both stability and fast response by applying appropriate filter strength at different stages of the control process.
2Speed
If filter coefficients are decreased to shorten settling time, then response speed improves, but overshooting increases
Solution Approach 1:
The patent implements parameter changes by adjusting filter coefficients based on system state. When fast response is needed, coefficients are optimized for speed; when stability is critical, coefficients are adjusted to suppress overshooting. This dynamic parameter adaptation resolves the contradiction between response speed and overshooting suppression.
3Stability of the object's composition
If excessive filtering is applied to improve stability, then overshooting is suppressed, but settling time extends
Solution Approach 1:
The patent applies partial filtering rather than excessive filtering by dynamically adjusting coefficient strength. The filter coefficients are optimized to provide just enough filtering to suppress overshooting without over-filtering, which would unnecessarily extend settling time. This principle of applying the minimum necessary action achieves stability efficiently.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A degree of overshooting at the time of response to a target value is suppressed and a settling time is shortened. A temperature control device includes a setting part, a target value filter, and a PID control part. The setting part sets a PID value including a proportional band and integral time and filter coefficients α and β of two-degree-of-freedom PID control. The target value filter calculates an internal target value from a target value of control using the filter coefficients α and β. The PID control part calculates an amount of operation for control using the PID value with the internal target value as an input. The setting part sets the filter coefficients α and β using the target value, an initial value at the start time of control of the target value, and the proportional band.