Patent ID: 8820341
Filing Date: 2014-09-02
Classification: F16H,Y10T

Abstract:
1. A method to detect the presence of hydraulic line pressure in a hydraulic control system, the method comprising: determining an estimated hydraulic line pressure of the hydraulic control system based upon an input flow and an output flow of hydraulic fluid; regulating the input flow and the output flow with a pressure control device, the pressure control device being energizable based on operator demand; fluidly connecting a pressure detection device to the pressure control device to obtain a measured hydraulic pressure surrounding the pressure detection device; configuring the pressure detection device to indicate a first operating state if the measured hydraulic pressure is below a threshold pressure when the pressure control device is de-energized; configuring the pressure detection device to indicate a second operating state if the measured hydraulic pressure exceeds the threshold pressure when the pressure control device is de-energized; comparing the estimated hydraulic line pressure to the threshold pressure and determining the first or second operating state indicated by the pressure detection device; applying an override function to correct the estimated hydraulic line pressure to a corrected hydraulic line pressure, based on said determining the first or second operating state indicated by the pressure detection device and said comparing the estimated hydraulic line pressure to the threshold pressure; and controlling the input flow and the output flow of hydraulic fluid based upon the corrected hydraulic line pressure.