Method of determining an operating state of a transmission latching valve

摘要

A valve monitoring system includes a latching valve, a travel sensor, and a processor. The latching valve has a snap spring, a valve piston, and an inlet port. The travel sensor is for measuring travel of the valve piston between an activation pressure and a zero pressure. The processor is connected to the travel sensor for calculating a rate of travel of the valve piston and determining a latched state of the valve. In some example embodiments, the activation pressure is greater than a normal operating pressure. In some example embodiments, determining a latched state of the valve includes calculating a derivative of the rate of travel.

主权项

1. A valve monitoring system comprising:
a latching valve with a snap spring, a valve piston, and an inlet port; a travel sensor for measuring travel of the valve piston between an activation pressure and a zero pressure; and, a processor connected to the travel sensor for calculating a rate of travel of the valve piston and determining a latched state of the valve, wherein:
the activation pressure is greater than a normal operating pressure;determining the latched state of the valve includes calculating a derivative of the rate of travel; and,the processor is configured to determine that the valve is in the latched state when the derivative shows little variation between 40% and 60% of a total travel distance of the valve piston.