A method for monitoring health of a hydraulic fluid subsystem is presented. The method includes determining a plurality of forces acting on an actuator of the hydraulic fluid subsystem, determining a plurality of parameters based on at least one of an actuator inlet flow rate, an actuator outlet flow rate, and the plurality of forces acting on the actuator, receiving a valve inlet pressure of at least one of oil and gas flowing through a pipe while entering a valve operationally coupled to the actuator and a valve outlet pressure of the at least one of the oil and the gas flowing through the pipe while flowing out of the valve, and monitoring the health of the hydraulic fluid subsystem based on at least one of the plurality of parameters, the valve inlet pressure, and the valve outlet pressure.

A method for monitoring health of a hydraulic fluid subsystem is presented. The method includes determining a plurality of forces acting on an actuator of the hydraulic fluid subsystem, determining a plurality of parameters based on at least one of an actuator inlet flow rate, an actuator outlet flow rate, and the plurality of forces acting on the actuator, receiving a valve inlet pressure of at least one of oil and gas flowing through a pipe while entering a valve operationally coupled to the actuator and a valve outlet pressure of the at least one of the oil and the gas flowing through the pipe while flowing out of the valve, and monitoring the health of the hydraulic fluid subsystem based on at least one of the plurality of parameters, the valve inlet pressure, and the valve outlet pressure.

A gas-pressure-driven apparatus includes a main body having a working chamber, a movable member moving relative to the main body with a pressure of the working chamber, a pressure sensor for detecting the pressure, a flow rate sensor for detecting the flow rate of the working gas. A method for controlling the apparatus includes calculating a pressure change amount from the detected pressure and an integrated flow rate from the detected flow rate when the pressure is changed in a state in which the volume of the working chamber cannot be changed, calculating an initial volume of the working chamber from the pressure change amount and the integrated flow rate, and calculating a post-change volume of the working chamber from the integrated flow rate and the initial volume after creation of a state in which the volume of the working chamber can be changed from the initial volume.

An example valve includes: a first port; a second port; a third port; a poppet configured to be subjected to (i) a first fluid force by fluid of the first port acting on the poppet in a proximal direction toward a poppet seat, and (ii) a second fluid force by fluid of the second port acting on the poppet in a distal direction; a pilot piston configured to be subjected to a pilot fluid force by a pilot fluid signal received at the third port; a check spring applying a spring force on the poppet in the proximal direction; and pilot spring applying a pilot spring force on the pilot piston in the proximal direction.

When hydraulic fluid discharged from a hydraulic actuator is to be recovered for driving a different hydraulic actuator, the recovery frequency is increased to achieve further energy saving. To this end, a pressure increasing circuit 36 is provided in which a communication pressure increasing valve 12 is disposed in a communication passage 26 that connects a bottom side line 23 of and a rod side line 24 a boom cylinder 4. A recovery control valve 11 is controlled such that, when a first operation unit 5 is operated in a boom lowering direction (own weight falling direction of the boom) and a second operation unit 6 is operated simultaneously, only if the pressure at the bottom side of the boom cylinder 4 is higher than the pressure at the arm cylinder side that is a recovery destination of hydraulic fluid, the recovery control valve 11 is opened to recover the flow rate discharged from the bottom side of the boom cylinder 4 to the arm cylinder side.

The invention relates to a method for indicating the position of a hydraulically actuated armature, having a piston (1.21) in a cylinder (1.2) for actuating the armature (1.1), which cylinder is connected by means of two hydraulic lines (2, 3) to a switch valve (7) through which the hydraulic lines can be switched between pressure-conducting feed flow and pressureless return flow, wherein the flow of the hydraulic fluid flowing through one of the hydraulic lines is converted into a number of electric pulses, each of which corresponds to a pre-determined unit of volume of the hydraulic fluid, the switch valve (7) is connected to supply lines (P, T), to which further switch valves (7) are connected for actuating further armatures (1.n), the switch valves (7) are connected via a branch line (T1) to the return line (T) common to all armatures, and wherein at each switch valve (7) in the branch line (T1) to the return line (T), a preload pressure is maintained which is higher than the pressure in the common return line (T). Furthermore, a program is provided which processes the pulses of the throughflow sensor and carries out a learning cycle.

A monitoring device includes a first pressure sensor that detects a first pressure value of a pressurized fluid in a first pipe, a second pressure sensor that detects a second pressure value of a pressurized fluid in a second pipe, and a detector that determines, on the basis of the first pressure value and the second pressure value, whether or not a piston has reached one end or the other inside a cylinder body.

A baler connectable to a tractor for providing round bales comprises: a frame supported on a wheel axle; a chamber, for receiving crops and for housing a formed bale, the chamber having a fixed, predetermined size; a tailgate connected to the frame and movable between a closed position and an open position; a conveying assembly which has a first portion provided in the frame and a second portion provided in the tailgate; a cylinder-piston actuator, which includes a closing chamber and moves the tailgate from the open position to the closed position; a binder, configured for binding the formed bale with a fastening element; a pressure sensor for detecting a control signal representative of a pressure inside the closing chamber of the cylinder-piston actuator; a control unit, configured to generate an alert signal as a function of the control signal.

A method is provided for detecting and quantifying obstructions in a gas network under pressure or vacuum. The gas network may be provided with a sensor(s) capable of recording the status of a source(s), consumers, or consumer areas. The method includes: a possible start-up phase; a baseline or zero phase; and an operational phase. The operational phase includes: reading out the first group and second group of sensors; re-estimating, determining or calculating the physical model or mathematical relationship on the basis of the read measurements from the sensors; determining or calculating of the existence of an obstruction in the system based on the difference and/or its derivatives between the parameters of the physical model or mathematical relationship as determined during the baseline or zero phase and the operational phase; generating an alarm and/or generating a degree of obstruction and/or generating the corresponding obstruction if an obstruction is detected.

A vehicle includes: a prime mover; a hydraulic fluid manifold; a hydraulic machine; a hydraulic accumulator; one or more hydraulic actuators; a valve arrangement; and a controller. The controller is configured to receive an actuator demand signal indicative of a demand to move the one or more hydraulic actuators; and to control the hydraulic machine and the valve arrangement to cause movement of the one or more actuators in accordance with the actuator demand signal by bringing the hydraulic accumulator into fluid communication with a first actuator chamber of the one or more hydraulic actuators, and to synchronise therewith changing a pressure in a second actuator chamber of the one or more hydraulic actuators. The second actuator chamber is in fluid communication with the hydraulic machine.