Speed-based flow device diagnostic system and method

摘要

A vehicle or other system includes a flow device, component, and controller. The controller executes a method of diagnosing flow performance in the vehicle/system. The flow device is a pump, blower, or fan. A calibrated upper speed limit is commanded from the flow device in response to detected enabling conditions. The device is turned off after maintaining the upper speed limit for a calibrated duration. The speed of the flow device is determined during a coast-down interval defined by a period between command of the upper speed limit and attaining a calibrated lower speed limit. An absolute rate of change of the speed over the coast-down interval is calculated, with the controller executing a control action when a maximum absolute slope of the calculated rate of change falls outside of a calibrated range during the coast-down interval.

主权项

1. A system comprising:
a flow device having a speed, wherein the flow device is configured to output a raw speed signal; a component in fluid communication with the flow device; and a controller in communication with the flow device that is configured to:
detect an enabling condition;command a calibrated upper speed limit from the flow device in response to the detected enabling condition;turn off the flow device after maintaining the calibrated upper speed limit for a calibrated stabilization interval;determine the speed of the flow device during a coast-down interval that is defined by the period between the command of the upper speed limit and attainment by the flow device of a calibrated lower speed limit;calculate a rate of change of the speed over the coast-down interval; andexecute a control action with respect to the flow device when a maximum value of the calculated rate of change falls outside of a calibrated range.