Heating Process Control for Finite-Time Temperature Settling

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Solution Overview

Problem

Heating processes without cooling mechanisms face challenges in controlling target temperatures to reach target values within specified times without overshooting, especially when process parameters such as gain, dead time, and time constant change, leading to potential temperature overshooting and inefficient steam usage.

Innovation Solution

A control device and method that models the heating process as including a dead time, a first-order lag, and an integration element, using finite time settling control with upper and lower limit constraints on the manipulation amount, and correcting the target temperature set value using a quadratic curve to ensure the temperature converges within a predetermined time without exceeding the target temperature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If feedback control by PI or PID controller is performed, then control is achieved, but temperature overshooting occurs when process parameters change

Engineering Contradiction:
Improvetemperature control reliabilityVSAvoidtemperature precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent changes the control approach from traditional PI/PID to finite time settling control, which explicitly accounts for process parameters (dead time, time constant, process gain) in the control law design. This allows the controller to adapt to parameter variations and prevent overshooting by design rather than relying on fixed gain tuning.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a set value correction mechanism that preemptively adjusts the target temperature profile based on the heating process characteristics. By correcting the set value in advance using a quadratic curve, the system prevents overshooting before it occurs, rather than reacting after the temperature exceeds the target.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If heating control is aggressive to reach target temperature quickly, then productivity improves, but temperature overshooting occurs

Engineering Contradiction:
Improveheating speedVSAvoidtemperature precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The set value correction using a quadratic curve prepares the temperature profile in advance, allowing the heating process to accelerate more aggressively while still converging smoothly to the target temperature without overshooting. This preliminary shaping of the set point enables faster response while maintaining precision.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The finite time settling control dynamically adjusts the manipulation amount based on real-time temperature deviation and process parameters. The control law adapts the heating aggressiveness throughout the process, allowing rapid heating when far from target and gentle approach when near target, optimizing both speed and precision.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If traditional control methods are used, then simple control structure is maintained, but temperature overshooting occurs when parameters change

Engineering Contradiction:
Improvecontrol structure simplicityVSAvoidtemperature control reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent incorporates explicit parameter identification (dead time, time constant, process gain) into the control law, transforming the control structure from fixed-gain to adaptive. While this increases mathematical complexity, it maintains operational simplicity through automated parameter estimation and provides robust reliability against parameter variations.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The finite time settling control uses continuous feedback of temperature measurements and identified process parameters to dynamically adjust the manipulation amount. This feedback mechanism ensures reliable temperature control even when process conditions change, as the controller continuously adapts to current system state.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4137910A1Control device, control method, and non-transitory computer readable storage medium
Publication Date: 2023.02.22 YOKOGAWA ELECTRIC CORP
  • EP4137910A1 patent drawingFigure 1
  • EP4137910A1 patent drawingFigure 2~4
  • EP4137910A1 patent drawingFigure 5

AI summary

A control device (40) is for a heating process which is a process of heating a target and does not include a cooling mechanism. The control device (40) includes a controller (42) configured to control a manipulation amount of the heating process such that a temperature of the target converges at a target temperature within a predetermined settling time without exceeding the target temperature based on a control scheme of modeling the heating process as a process including a dead time, a first-order lag, and an integration element and controlling the heating process by finite time settling control.