Fan Coupling Control Using Feedforward Oil Amount Estimation
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Solution Overview
Problem
Existing fan coupling devices face challenges in accurately controlling the amount of working fluid in the labyrinth chamber, leading to inefficiencies in maintaining the target rotation speed and acceleration of the fan, as conventional feedback control methods struggle to converge the estimated oil amount to the target oil amount effectively.
Innovation Solution
A controller for the fan coupling device that combines feedback and feedforward control methods, using a solenoid valve to regulate the working fluid in the labyrinth chamber, where the control unit calculates a final control command value by adding a feedforward control command value based on the estimated oil amount and rotation speed to the feedback control command value, ensuring accurate oil amount control and maintaining constant fan rotation speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If feedback control is executed based on deviation between actual and target rotation speed, then the fan rotation speed can be regulated, but the amount of working fluid in the labyrinth chamber cannot be accurately controlled
Solution Approach 1:
The patent applies preliminary action by estimating the working fluid amount in advance using a calculation unit that computes the working fluid amount based on the rotation speed of the drive shaft and the rotation speed of the fan. This estimated value is then used by the control unit to determine the opening degree of the solenoid valve, enabling proactive control rather than reactive control based solely on rotation speed deviation.
Solution Approach 2:
The patent implements feedback control by using the estimated working fluid amount as feedback information. The control unit compares the estimated working fluid amount with the target working fluid amount and adjusts the solenoid valve opening degree accordingly. This creates a closed-loop control system that continuously monitors and corrects the working fluid amount to match the target value.
2Productivity
If the solenoid valve opening degree is controlled only by feedback control, then the system remains simple, but the convergence to target oil amount is slow and inaccurate
Solution Approach 1:
The control unit performs preliminary calculation of the required solenoid valve opening degree based on the estimated working fluid amount and target working fluid amount. This allows the system to proactively adjust the valve opening to achieve the target oil amount quickly and accurately, rather than relying solely on gradual feedback correction.
Solution Approach 2:
The system uses the estimated working fluid amount as feedback to continuously adjust the solenoid valve opening degree. This feedback mechanism ensures that the actual working fluid amount converges to the target value by comparing the estimated amount with the target amount and making real-time corrections to the valve opening.
3Measurement precision
If feedforward control is added to improve convergence speed, then the control accuracy improves, but the device complexity increases
Solution Approach 1:
The control unit performs preliminary determination of the solenoid valve opening degree by calculating the required opening based on the estimated working fluid amount and target working fluid amount. This feedforward calculation enables the system to proactively adjust the valve opening to achieve the target oil amount, improving both convergence speed and control accuracy.
Solution Approach 2:
The system integrates feedback control by using the estimated working fluid amount to continuously monitor and adjust the solenoid valve opening degree. The control unit compares the estimated amount with the target amount and makes real-time corrections, creating a closed-loop control system that ensures accurate convergence to the target working fluid amount.
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
This approach allows for precise control of the working fluid in the labyrinth chamber, enhancing the responsiveness and accuracy of fan acceleration and deceleration, ensuring the fan operates at the desired rotation speed and improving overall system efficiency.
Implementation Method 1
a solenoid valve configured to open and close a communicating port formed in the divider to regulate an amount of the working fluid in the labyrinth chamber
Implementation Method 2
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 the working fluid
Implementation Method 3
the feedback control command value being calculated based on deviation between the estimated amount and the target amount
Data Source
AI summary
A controller includes: a control unit configured to calculate a control command value of an opening degree of a solenoid valve to control an opening degree of the solenoid valve; and an acquisition unit configured to acquire an estimated amount and a target amount of a working fluid in a labyrinth chamber, and a rotation speed of a drive shaft. The control unit calculates a final control command value based on a feedback control command value and a feedforward control command value, and controls the solenoid valve, the feedback control command value being calculated based on deviation between the estimated amount and the target amount, the feedforward control command value being used to maintain a rotation speed of a fan constant based on the estimated amount and the rotation speed of the drive shaft.