Fan Coupling Controller Dynamic Integral Control Threshold
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Solution Overview
Problem
In fan coupling devices, when the deviation between actual and target rotation speeds is small but the working fluid amount in the labyrinth chamber is large, the responsiveness of the fan may deteriorate, leading to issues like hunting or steep fall in rotation speed.
Innovation Solution
A controller for the fan coupling device that includes an acquisition unit to measure the deviation and fluid amount parameters, and a control unit to execute feedback control, stopping integral control when the fluid amount parameter exceeds a threshold, and adjusting the threshold based on the drive shaft's rotation speed to prevent responsiveness deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If integral control is stopped only when deviation is equal to or greater than a threshold, then the control is simple, but the responsiveness deteriorates when fluid amount is large
Solution Approach 1:
The control method dynamically adjusts the integral control stop condition based on fluid amount. When fluid amount is large, integral control is stopped at a smaller deviation threshold, improving responsiveness. When fluid amount is small, integral control continues at larger deviations, maintaining stability. This dynamic adaptation resolves the contradiction between simple control logic and responsive performance.
Solution Approach 2:
The invention changes the control parameter (deviation threshold for stopping integral control) based on the fluid amount parameter. By making the threshold variable rather than fixed, the system achieves both simplicity and responsiveness - the threshold automatically adjusts to current operating conditions without complex control architecture.
2Stability of the object's composition
If integral control continues when fluid amount is large, then the control maintains stability, but hunting and steep fall occur
Solution Approach 1:
The system uses feedback from the fluid amount sensor to adjust the integral control behavior. When fluid amount is detected to be large, the feedback mechanism stops integral control at a smaller deviation threshold, preventing hunting and steep fall. This feedback-based adaptation maintains stability while eliminating harmful oscillations.
Solution Approach 2:
The invention applies preliminary anti-action by stopping integral control before hunting and steep fall can occur. By monitoring fluid amount and preemptively adjusting the integral control stop condition, the system prevents the harmful effects rather than reacting to them after they manifest.
3Device complexity
If the threshold is fixed, then the control is simple, but responsiveness deteriorates at high rotation speeds
Solution Approach 1:
The threshold dynamically increases with drive shaft rotation speed up to a prescribed value, then lowers at higher speeds. This dynamic threshold adjustment maintains responsiveness across different operating conditions while keeping the control mechanism relatively simple, using only rotation speed as the basis for threshold modification.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively restrains the deterioration of responsiveness by adjusting control methods based on fluid amount and rotation speed, ensuring stable fan operation by switching between PI and P control depending on the fluid amount and rotation speed conditions.
Implementation Method 1
The labyrinth chamber is formed between the housing and the rotor in the housing and configured to transmit rotational motive power of the rotor to the housing through working fluid
Implementation Method 2
The control unit is configured to execute feedback control including at least integral control of the deviation so as to control the regulation mechanism. When the fluid amount parameter is equal to or greater than a threshold, the control unit executes the feedback control in a state where the integral control is sopped.
Data Source
AI summary
A controller includes: an acquisition unit that acquires a deviation between an estimated amount and a target amount of a working fluid in the labyrinth chamber, and a fluid amount parameter corresponding to the estimated amount; and a control unit that executes feedback control including at least integral control of the deviation so as to control a regulation mechanism. When the fluid amount parameter is equal to or greater than a threshold, the control unit executes the feedback control in a state where the integral control is stopped.