Clutch Oil Supply Control Using Angular Acceleration Feedback
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Solution Overview
Problem
Existing electromagnetically controlled clutches for cooling fans face challenges in rapidly achieving the desired oil amount in the torque transmission chamber and improving response followability.
Innovation Solution
A control device that calculates desired rotation speeds and angular accelerations to control the valve member, using proportional, feedforward, and integral terms to adjust oil supply, enhancing response followability by focusing on angular acceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional feedback control based on rotation speed is used, then the control system is simple, but the response followability is insufficient
Solution Approach 1:
The patent changes the control parameter from rotation speed to angular acceleration. By calculating angular acceleration from rotation speed measurements and using it as the feedback parameter, the system achieves faster response followability without adding complex hardware. The control unit calculates angular acceleration by differentiating rotation speed with respect to time, transforming the control approach to improve dynamic response.
Solution Approach 2:
The patent implements feedback control by continuously measuring rotation speed, calculating angular acceleration, comparing it with desired angular acceleration, and adjusting the valve member position accordingly. This closed-loop feedback mechanism ensures the actual angular acceleration follows the desired trajectory, improving response followability while maintaining a relatively simple control structure.
2Speed
If the valve member operation is controlled only by rotation speed feedback, then the control structure is simple, but the oil supply adjustment is too slow
Solution Approach 1:
The patent transforms the control parameter from rotation speed to angular acceleration. By using angular acceleration as the feedback parameter, the system can detect and respond to changes in rotational behavior more quickly. This parameter transformation enables faster oil supply adjustment because angular acceleration directly reflects the dynamic demand for torque transmission.
Solution Approach 2:
The system calculates desired angular acceleration in advance based on the difference between actual and target rotation speeds. This preliminary calculation of the required acceleration allows the control system to proactively adjust oil supply before the rotation speed deviation becomes significant, thereby speeding up the response.
3Measurement precision
If proportional control only is used, then the control is simple, but the steady-state accuracy is insufficient
Solution Approach 1:
The patent implements integral feedback control by accumulating the error between desired and actual angular acceleration over time. This integral term ensures that any persistent error is progressively eliminated, achieving high steady-state accuracy. The control unit adjusts the valve member position based on the accumulated error, guaranteeing that the system reaches and maintains the target rotation speed.
Solution Approach 2:
The patent uses angular acceleration as the feedback parameter for integral control. By integrating the angular acceleration error over time, the system achieves precise control of rotation speed. This parameter transformation enables the integral control to effectively eliminate steady-state errors that would persist with simple proportional control.
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 control device significantly improves the response followability of the clutch by rapidly adjusting oil supply, allowing the cooling fan to quickly reach and maintain the desired rotation speed.
Implementation Method 1
when the electromagnet is ON (excited), the oil supply port is opened by the armature being pulled toward a magnetic loop element side against a spring force of the leaf spring
Data Source
AI summary
A control device for a clutch, which is provided between an operation machine and a drive shaft of an engine, controls an operation of a valve member for opening and closing an oil supply port through which an oil reservoir chamber and a torque transmission chamber communicate. The control device refers to a desired rotation speed of a rotating body of the operation machine and to an acquired rotation speed of the rotating body of the operation machine, calculates a proportional term manipulated variable based on a deviation between an angular acceleration of the rotating body and a desired angular acceleration, and controls the operation of the valve member on the basis of this calculated proportional term manipulated variable.