Adaptive control of externally controlled fan drive
AssigneeUsui International Corp.
InventorsNikhil D. Bhat, Masato Yamada, Sameer A. Joshi, Ananthakrishnan Surianarayanan
Life of this patent
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Abstract
An externally controlled fan drive includes a fluid clutch that alters torque delivered to a fan housing to rotate the fan housing at a target fan speed. An adaptive controller measures the actual fan speed and adaptively updates the control logic to compensate for variable physical characteristics of the fan device.
Claims6
An externally controlled fan device, comprising:
- an external controller for receiving inputs indicative of a target fan speed appropriate for the cooling needs of an engine;
- a fluid clutch for transferring torque to the fan device for achieving an actual fan speed, the fluid clutch including a valve for selectively controlling a flow of fluid to a torque transmission chamber;
- means for controlling a duty rate of opening and closing the valve to control the fluid in the torque transmission chamber and thereby controlling the actual fan speed;
- means for measuring and storing fluid control data at each of a plurality of intervals;
- means for measuring and storing the actual fan speed at each of a plurality of intervals;
- and
- adaptive control means for developing and sequentially updating an algorithm based on the measured and stored fluid control data and the measured and stored actual fan speeds and for producing a fluid control signal to adaptively control the fluid for substantially conforming the actual fan speed to the target fan speed.
A method for adaptively controlling a fan device, the fan device having a fluid clutch with a fluid for selectively applying torque for rotating a fan at an actual fan speed proportional to the torque, the method comprising:
- inputting a target fan speed selected to accommodate cooling needs of an engine;
- operating an electromagnet for sequentially opening and closing a valve for controlling fluid in the fluid clutch and for thereby controlling the actual fan speed, the electromagnet being pulse width modulated for adjusting a duty rate for opening and closing the valve;
- measuring and storing duty rate data for each of a plurality of intervals;
- measuring and storing the actual fan speed at each of the plurality of intervals;
- comparing the actual fan speed to the target fan speed at each of the plurality of intervals;
- and
- developing and updating a deterministic auto-regressive algorithm based at least on the measured and stored duty rates and the measured and stored actual fan speed to adaptively control the fluid for substantially conforming the actual fan speed to the target fan speed.
Dependencies are inferred from the claim text.