Patent ID: 9423800
Filing Date: 2016-08-23
CPC Classification: F15B,G05D,Y10T

Claim Text:
1. A method for initiating and implementing fail operational modes in an electro-hydraulic system comprising the steps of: (a) providing a plurality of valve assemblies, each valve assembly having at least one of a pressure sensor and a position sensor in communication with an electronic system controller, the valve assemblies being in fluid communication with a hydraulic actuator, wherein the plurality of valve assemblies includes a first valve assembly in fluid communication with a head side of the actuator and a second valve assembly in fluid communication with a rod side of the actuator, wherein the actuator is a linear actuator associated with a lifting function of a work machine; (b) detecting a fault condition with one of the sensors; (c) determining a sensor type associated with the fault condition wherein a first sensor type is a fault condition is associated with one of the pressure sensors and a second sensor type is associated with a fault condition one of the position sensors, (d) determining a sensor location associated with the fault condition wherein a first location is associated with a sensor located at an upstream side of the actuator and a second location is associated with a sensor located at a downstream side of the actuator; (e) where a position sensor has failed, determining an actuator state the actuator being in a passive state or an overrunning state; and (f) initiating and implementing one of a plurality of fail operational modes based on the determination of the sensor type, the sensor location, and the actuator state associated with the fault condition, wherein initiating and implementing one of a plurality of fail operational modes includes disabling a normal control algorithm associated with the faulted sensor, the fail operational modes including: