A braking system including a brake actuator, a control valve, a control assembly, and at least one pressure sensor. The control valve is disposed to direct hydraulic fluid to the brake actuator at a rate corresponding to a magnitude of a control signal. The control assembly includes a mixed-mode control system. The at least one pressure sensor is configured to measure a pressure of the hydraulic fluid to the brake actuator. The control assembly is configured to determine a position of the brake actuator. The mixed-mode control system is configured to determine a position command and a pressure command. The mixed-mode control system is configured to adjust the magnitude of the control signal based on at least one of the position command and the pressure command so as to reposition the brake actuator from a first position to a second position.

Passenger restraint systems are provided. The restraint systems can include: a passenger seat supported by a frame; a restraint bar pivotably attached to the frame; and at least one piston operably engaged between the restraint bar and the frame. Restraint system pistons are provided. The pistons can include: a central chamber housing a piston head and rod; a fluid reservoir in fluid communication with the central chamber; and at least one electromechanical valve operable between an open and a closed position. Methods for restraining a passenger within a seat are also provided.

A servo actuator is provided which may comprise a controller configured to control a plurality of solenoid valves based upon an output signal. The plurality of solenoid valves may be used to control the position of the object. For example, a set of solenoid valves, of the plurality of solenoid valves, may be configured to conduct fluid from a tank into a first chamber of the cylinder, conduct fluid from the tank into a second chamber of the cylinder, conduct fluid from the second chamber of the cylinder into a first solenoid valve and/or conduct fluid from the first chamber of the cylinder into the first solenoid valve. The first solenoid valve, of the plurality of solenoid valves, may be configured to conduct fluid from the set of solenoid valves into a vent valve based upon a pulse width modulation (PWM) signal received from the controller.

A pressure control device is provided and includes a body which has a groove-shaped flow path including a groove part and a widened part connected to the groove part and having a width larger than a width of the groove part, and a filter unit which captures foreign matters mixed in a fluid which passes through the groove-shaped flow path. The filter unit includes a frame body being in a cylindrical shape and including a through hole part which penetrates in a direction along a central axis, and at least one filter member being in a planar plate shape disposed to intercept the through hole part and supported inside the frame body, in which the filter unit is accommodated in the widened part so that a direction orthogonal to the central axis of the frame body is along a depth direction of the widened part.

An example valve includes: a sleeve having a plurality of sleeve openings; a first conduit configured to be in hydraulic communication with a first chamber, where a first pressure sensor is disposed in the first conduit and configured to measure a pressure level of fluid in the first chamber; a second conduit configured to be in hydraulic communication with a second chamber, where a second pressure sensor is disposed in the second conduit and configured to measure a pressure level of fluid in the second chamber; a spool rotatable within the sleeve, wherein the spool includes a plurality of spool openings respectively corresponding to the plurality of sleeve openings; a rotary actuator coupled to the spool and configured to rotate the spool within the sleeve in clockwise and counter-clockwise directions; and a controller configured to cause the spool to rotate to one of a plurality of rotary positions.

A pressure regulator includes an outlet pressure sensor, loading and unloading electromagnetic valves, and a regulator control circuit operatively connected to the loading and unloading electromagnetic valves and configured to pilot the loading and unloading electromagnetic valves to cancel an error signal given by a difference between an inlet signal corresponding to a desired outlet pressure and a feedback signal provided by the outlet pressure sensor. The pressure regulator includes an engaging current analysis circuit to detect and store reference characteristics of the engaging current of the solenoid of the loading electromagnetic valve in a stable inlet pressure condition, monitor the engaging current to detect any variation of its characteristics with respect to the corresponding reference characteristics, and, in the event of variation, provide a pilot modulation signal to at least one of the loading or unloading electromagnetic valves or a pressure variation signal to the regulator control circuit.

A pressure control device includes a body having a groove-shaped flow path including a groove part and a widened part, and a filter unit capturing foreign matters mixed in a fluid which passes through the groove-shaped flow path; the filter unit having a frame body including a through hole part and a filter member in a planar plate shape disposed with respect to the through hole part, and the filter unit being accommodated in the widened part. The frame body has: a first part having a first shape, a second part having a second shape smaller than the first shape, and a step part located at a boundary part between the first part and the second part The second part has a storage part provided in a penetrating manner on a bottom part side of the groove-shaped flow path and storing the captured foreign matters.

The invention relates to a control device for a hydraulic consumer (22), susceptible to vibrations, comprising a valve (24) having a control spool (40), which can be controlled by means of an actuating device (46), wherein the valve (24) has a pressure supply port (P), to which a pressure compensator valve can be connected, which can be supplied with pressure fluid from a pressure supply device, wherein the actuating device (46) has a motor (74) and wherein a load-pressure-dependent force on the control spool (40) can be generated by means of a control device (66). In accordance with the invention, this force at the control spool (40) acts on an electronic motor controller (208) of the DC motor (74), which detects a change of the force and acts as a damping of the vibrations of the consumer (22) against this change of force.

An electro hydraulic servo valve and a method of controlling pressure therein includes a first stage unit including a moveable direct drive valve, a second stage unit including a centering spring and a second stage spool valve that is fluidly connected to the moveable direct drive valve, and at least one pressure feedback fluid line fluidly connected to the first stage unit. The moveable direct drive valve selectively supplies fluid pressure to the second stage unit. Motion of the second stage unit is arrested using the centering spring and motion of the first stage unit is arrested when pressure is fed back to the first stage unit. A supply pressure or a return pressure is metered using the pressure feedback fluid line.

A method for operating a fluid system including the steps: receiving or determining a set value for a stroke of the working valve, determining an actual value for the stroke of the working valve using a sensor signal of a position sensor, determining a deviation value of a working valve in dependence on sensor signals of a supply pressure sensor and a working pressure sensor and a position sensor and a sensor system, and performing a processing of the set value for the stroke of the working valve, the actual value for the stroke of the working valve and the deviation value to a control signal for driving the working valve.