Abstract: A vehicle management system includes a processing circuit. The processing circuit is configured to acquire location information relating to a location of the vehicle, determine if the vehicle has arrived at a destination based on the location information, and provide a signal to switch at least one of a transmission of the vehicle or a braking subsystem of the vehicle from an operational condition to a locked condition in response to at least the vehicle arriving at the destination, thereby preventing undesired operation of the vehicle.

Abstract: An electromagnetic actuating device includes a pole tube that is substantially cylindrical overall, an armature situated radially inside the pole tube, and an electromagnetic coil situated radially outside the pole tube, the pole tube having a first axial end and a second axial end. The pole tube is configured as a sleeve that is stamped and is brought into its shape by reshaping, the sleeve having, close to its first axial end, openings that extend in the circumferential direction.

Abstract: A system for charging and discharging at least one hydraulic accumulator (10) can be connected to a valve control device (12). The valve control device (12) has at least one logic valve (14). A shuttle valve (16) and a hydraulically operated switching valve (18) are also provided. The valves (14, 16, 18) are interconnected such that the hydraulically actuatable switching valve (18) compares the accumulator pressure (pA) to a minimum accumulator pressure (pA0) that can be adjusted via the control pressure setting of this switching valve (18).

Abstract: Methods and systems for wirelessly transmitting power and/or data.

Abstract: To provide a work machine that can stop unexpected operation of actuators faster than it actually occurs even if unintended operation occurs at the time of gate lock lever switching that leads to such unexpected operation. In the work machine, a controller switches a lock valve from a lock position to a release position in a case where a lock operation device is operated from a permission position to a prohibition position; decides, on the basis of a result of detection by a pressure sensor, whether or not a pilot hydraulic fluid has been output from a pilot valve until first time elapses after the lock valve is switched to the release position; keeps the lock valve at the lock position if it is decided that the pilot hydraulic fluid has been output until the first time elapses; and switches the lock valve from the lock position to the release position if it is decided that the pilot hydraulic fluid has not been output until the first time elapses, and second time elapses.

Abstract: An electrohydraulic linear actuator comprises a housing consisting of a tubular profile, which forms a housing shell and in which there is a plurality of cavities, and which is closed at the ends by two housing covers fitted to the ends of the housing shell. A first cavity of the tubular profile forms a cylinder which forms the hydraulic cylinder of a double-acting synchronous cylinder and a second cavity which extends parallel to the first cavity accommodates a hydraulic unit in addition to the hydraulic cylinder, and a hydraulic oil reservoir is formed in said second cavity. Two working chambers of the hydraulic cylinder are separated from each other by a piston unit. The housing has at least one through-hole for a coupling element which forms a mechanical interface with the piston unit. The electric motor of the hydraulic unit is configured as a brushless outrunner motor.

Abstract: A downforce controller for an agricultural implement having a double-acting hydraulic cylinder. The cylinder is configured to be coupled to an agricultural row unit and an agricultural toolbar for transmitting a net downforce between the agricultural toolbar and the agricultural row unit. A first pressure in the first chamber of the cylinder and a second pressure in the second chamber of the cylinder having counteracting effects on the net downforce. A manifold coupled to the cylinder is in fluid communication with the first chamber. A pressure control valve supported by the manifold is in fluid communication with the manifold and the first chamber.

Abstract: A downforce controller for an agricultural implement having a double-acting hydraulic cylinder. The cylinder is configured to be coupled to an agricultural row unit and an agricultural toolbar for transmitting a net downforce between the agricultural toolbar and the agricultural row unit. A first pressure in a first chamber of the cylinder and a second pressure in a second chamber of the cylinder have counteracting effects on the net downforce. A manifold coupled to the cylinder is in fluid communication with the first chamber. A pressure control valve coupled to the manifold is in fluid communication with the manifold and the first chamber.

Abstract: A downforce controller for an agricultural implement having a double-acting hydraulic cylinder. The cylinder is configured to be coupled to an agricultural row unit and an agricultural toolbar for transmitting a net downforce between the agricultural toolbar and the agricultural row unit. A first pressure in the first chamber of the cylinder and a second pressure in the second chamber of the cylinder having counteracting effects on the net downforce. A manifold coupled to the cylinder is in fluid communication with the first chamber. A pressure control valve supported by the manifold is in fluid communication with the manifold and the first chamber.

Abstract: A downforce controller for an agricultural implement having a double-acting hydraulic cylinder. The cylinder is configured to be coupled to an agricultural row unit and an agricultural toolbar for transmitting a net downforce between the agricultural toolbar and the agricultural row unit. A first pressure in a first chamber of the cylinder and a second pressure in a second chamber of the cylinder have counteracting effects on the net downforce. A manifold coupled to the cylinder is in fluid communication with the first chamber. A pressure control valve coupled to the manifold is in fluid communication with the manifold and the first chamber.

Abstract: A hydraulic driving system includes a hydraulic pump, a driving source, a hydraulic cylinder, a closed circuit hydraulic path between the pump and cylinder, a pump-flow-rate control unit controlling a discharge flow rate of the pump, a flow rate control valve between the pump and the cylinder in the fluid path, a directional control unit, a target flow rate setting unit and a control device. The directional control unit allows a flow of fluid from the pump to the cylinder and prohibits a flow of fluid from the cylinder to the pump when fluid is supplied from the pump to the cylinder via the flow rate control valve. The control device controls fluid flow to the cylinder with the flow rate control valve when the target flow rate is within a prescribed range, and with the pump-flow-rate control unit when the target flow rate is greater than the prescribed range.

Abstract: There is provided a hydraulic excavator in which occurrence of minute vibrations in a control lever can be suppressed. A boom-raising proportional solenoid valve is provided in a boom-raising pilot conduit. A boom-lowering proportional solenoid valve is provided in a boom-lowering pilot conduit. A controller controls an opening degree of the boom-lowering proportional solenoid valve based on a pressure generated in the boom-lowering pilot conduit between the control lever and the boom-lowering proportional solenoid valve, and controls an opening degree of the boom-raising proportional solenoid valve. An amount of increase in current per unit time when the controller outputs, to the boom-lowering proportional solenoid valve, an instruction signal for instructing an increase in opening degree is smaller than an amount of increase in current per unit time when the controller outputs, to the boom-raising proportional solenoid valve, an instruction signal for instructing an increase in opening degree.

Abstract: According to various embodiments, a microfluidic agitator device may be provided. The microfluidic agitator device may include: an air inlet; an air outlet; an elastic diaphragm provided between the air inlet and the air outlet and configured to oscillate if an airflow from the air inlet to the air outlet is provided; and a chamber coupled to the elastic diaphragm.

Abstract: The present invention relates to a method of determining the static force developed by a servo-control (10) having an actuator (20) and a hydraulic distributor control valve (30), with the actuator (20) including at least one cylinder (21) and a slidable element (25). The method comprises determining an instantaneous travel speed of the slidable element (25) relative to the cylinder (21) and determining the static force based at least in part on the instantaneous static force developed by the servo-control (10), the predetermined maximum static force, the instantaneous travel speed raised to the second power, and the maximum travel speed of the slidable element (25) relative to the cylinder (21) raised to the second power.

Abstract: Valve actuator system and a system for operation of valves, which valve comprises a valve housing, which valve housing comprises at least one inlet and at least one outlet, which valve housing further comprises a valve closing element, which valve element is mechanical connected to a valve actuator, which valve actuator comprises at least one piston, which piston is moved in a housing by a pressurized fluid in at least one direction, which valve actuator is connected to a control valve which control valve regulates a flow of a liquid medium from a pressure source to a first cavity chamber in the hosing of the valve actuator where the valve is a sanitary valve primarily for regulation of a flow of Fluid food, which valve actuator is activated by a liquid medium.

Abstract: A system has an actuator having a rotor or a linear piston, and ports for hydraulic fluid, an electro-mechanical sensor sensing position of the rotor or linear piston, a valve having a 1 plug in a bore of a valve body, the plug having cross bores aligning with passages within the valve body communicating inlet and outlet ports depending on relative position of the plug in the bore of the valve body, a servo motor to move the plug around or along the axis to different positions to align individual ones of the cross bores with individual ones of the passages communicating with individual ones of the ports, and a programmable controller coupled to the electro-mechanical sensor and to the servo motor, the controller enabled to control the servo motor to accomplish programmed movement and position of the rotor or linear piston of the hydraulically-driven actuator.

Abstract: A hydraulic control device for a forklift includes a hydraulic pump, a single electric motor for driving the hydraulic pump, an outflow control mechanism provided between a lift cylinder and the hydraulic pump, a flow control valve provided between the outflow control mechanism and a draining portion, and a controller. When a lowering operation of a fork and either forward or rearward mast tilting operations of a mast are performed at the same time, the controller controls the electric motor based on a target speed of the hydraulic pump. The flow control valve controls the flow rate of hydraulic fluid from the lift cylinder to the hydraulic pump and the flow rate from the lift cylinder to the draining portion in accordance with the difference between the actual rotation speed of the hydraulic pump and the target rotation speed of the hydraulic pump.

Abstract: A hydraulic control device includes: a hydraulic pump connected in parallel to steering and boom cylinders; a steering control valve that controls the direction of operating oil flowing through the steering cylinders; a boom control valve that connects the hydraulic pump to a tank when the valve is at a neutral position and controls the direction of the oil flowing through the boom cylinders when the valve is at an offset position; a meter-in pressure compensator that increases flow rate of the oil flowing through a variable restrictor of the steering control valve in accordance with pressure in front of and behind the restrictor; and a bleed-off pressure compensator that decreases flow rate of the oil flowing through the boom control valve in accordance with the increase in pressure of the oil flowing through the steering cylinders to maintain the predetermined pressure of the oil in the steering control circuit.

Abstract: Disclosed is a boom cylinder control circuit for a construction machine including a boom cylinder having an ascending-side chamber and a descending-side chamber. The boom cylinder control circuit includes: a first floating chamber with first and second input ports connected to the descending-side chamber and the ascending-side chamber, respectively, at one side, and first and second output ports connected with the drain tank, at the other side, and is switched to selectively connect the first and second input ports to the first and second output ports in accordance with an operational signal of the floating selection operation part; and a second floating valve of which one side is connected to the first output port and the other side is connected to the drain tank to selectively connect the first output port with the drain tank in accordance with the operational signal.

Abstract: An adhesive dispensing module includes a pneumatic actuator for actuating reciprocating movement of a piston on a dispenser valve member. The pneumatic actuator includes a valve element and a pneumatic housing with an inlet chamber, an exhaust chamber, and a piston chamber. The valve element includes a plurality of inlet passages and a plurality of exhaust passages. The valve element rotates from a first position in which the inlet passages deliver pressurized air from the inlet chamber to the piston chamber, to a second position in which the exhaust passages exhaust pressurized air from the piston chamber to the exhaust chamber. The valve element also includes a plurality of fins configured to be driven by an electromagnetic coil to move the valve element.

Abstract: The present disclosure provides a control system of a powered machine. The control system includes a hydraulic motor configured to drive a track system of the machine. The motor is operable with a variable displacement. A control valve is fluidly coupled to the motor. In addition, the control system includes a controller and an electro-hydraulic valve disposed in electrical communication with the controller and fluid communication with the control valve. The electro-hydraulic valve receives a signal from the controller, and based on the signal, the electro-hydraulic valve hydraulically varies the start of control pressure of the motor.

Abstract: A control system for controlling the movement of a system such as a hydraulic servo controlled gimbal systems. The system includes a plurality of actuators and sensors that sense the position of the actuators. On start up, a control system determines the present orientation of the system and compared it to a user defined desired orientation. The system operates in a first mode on start up where the control system moves the actuators so that the system is moved form the present orientation to the desired orientation at a controlled rate. Once the desired orientation is reached, control is then passed to a user controlled device such as a joystick.

Abstract: There is provided a device and method for high speed hydraulic actuation. The method includes adjusting a position of an actuator using a hydraulic pressure regulator. Adjusting the position of the actuator includes increasing pressure on the hydraulic pressure regulator to open the actuator using a first solenoid, or decreasing pressure on the hydraulic pressure regulator to close the actuator using a second solenoid.

Abstract: The present invention relates to a hydraulic control system for construction machinery capable of variably adjusting a set pressure of a relief valve, which controls a set pressure of a hydraulic system, according to a value inputted by means of pressure in the hydraulic system or the manipulation of a joystick.

Abstract: A hydraulic machine includes a number of piston/cylinder units which are each controlled by valves positioned upstream and downstream. The valves are in turn activated by an electronic regulator to switch the hydraulic machine selectively into a pump operating mode and a motor operating mode. The regulator selectively switches the individual piston/cylinder units or unit groups separately from one another into individually selectable operating modes as a function of certain regulating variables.

Abstract: A hydraulic driving system includes a hydraulic pump, a driving source, a hydraulic cylinder, a closed circuit hydraulic path between the pump and cylinder, a pump-flow-rate control unit controlling a discharge flow rate of the pump, a flow rate control valve between the pump and the cylinder in the fluid path, a directional control unit, a target flow rate setting unit and a control device. The directional control unit allows a flow of fluid from the pump to the cylinder and prohibits a flow of fluid from the cylinder to the pump when fluid is supplied from the pump to the cylinder via the flow rate control valve. The control device controls fluid flow to the cylinder with the flow rate control valve when the target flow rate is within a prescribed range, and with the pump-flow-rate control unit when the target flow rate is greater than the prescribed range.

Abstract: In a electropneumatic field device, an electrical field input and a pneumatic supply input are provided. At least one field output is provided at which a field output signal is output based on a field control signal received via the electrical field input. A group comprising at least two modular components of different functionality is provided and at least one modular slot for occupation with either of said modular components from said group. The at least two modular components of the group and the at least one slot are modularly adapted to one another such that interfaces of the slot and interfaces of either of said modular components in the seat merge into one another when the slot is occupied with either of said modular components so that the modular component which is in the slot is connected to the electrical field input and to the at least one field output.

Abstract: Provided an electrically-operated hydraulic actuator unit that includes an electrically-operated motor controlled by a control apparatus and actuating a volume adjusting mechanism through driving-side and driven-side arms, and a clutch mechanism in which the driven-side arm presses a contact member against a clutch case so that the driven-side arm is locked when a force from the volume adjusting mechanism is applied to the driven-side arm. The control apparatus can set duties of first to fourth drive signals to be output to the electrically-operated motor in a neutral-side start period, a neutral-side ordinary actuation period, a higher-volume-side start period and a higher-volume-side ordinary actuation period. The duties of the first and fourth drive signals are larger than that of the second drive signal, the duty of the third drive signal is larger than that of the fourth drive signal, and an integrated ON-time of the third drive signal is larger than that of the first drive signal.

Abstract: A vacuum lock having a main body portion, a cylinder and a piston is described. The cylinder is disposed within the main body portion and has an opening. The cylinder has one or more sealing rings disposed on an inside surface and an air vent opposite the opening. The vacuum lock can further include a piston adapted to fit in the cylinder and guides. The vacuum lock can also include a valve coupled to the air vent.

Abstract: The invention provides a vacuum control valve configured to control the vacuum pressure in the vacuum chamber. The vacuum control valve includes a control valve main body, an operation unit, a cylinder, a biasing unit, and a bellofram. The operation unit and the cylinder include a valve opening manipulation chamber and a shutoff load generation chamber. The shutoff load generation chamber is configured to have a common axial center line with the valve opening manipulation chamber and to generate a load applied to the operation unit in a direction for reducing the lift in accordance with a supply of the working fluid. And the shutoff load generation chamber may be formed in an interior of the rod.

Abstract: A pneumatic actuator air flow control system includes a pneumatic rotary actuator (PRA) and a solenoid air flow control valve (SAFCV). The PRA contains an air reservoir and a vane housing allowing pressurized air to rotate an air-driven vane. The SAFCV includes a flow control valve body (FCVB), a pilot solenoid valve (PSV) and a switch system, wherein the FCVB and the PRA can be connected to direct the pressurized air into the air reservoir, and the PSV is used to control the pressurized air in and out of the PRA to change the vane's rotation movement in the vane housing. Additionally, the switch system allows users to switch between a double-acting and fail-safe operation. When there is no pressurized air and/or electrical power and if an emergent need to open or close the valve, a manual override in the PSV can be used without further installation of a declutchable manual gear operator or external piping when there is no pressurized air and/or electrical power.

Abstract: The present invention relates to a pressure regulating device (1), in particular a hand- or foot-operated hydraulic controller for a heavy construction machine, characterised in that it comprises an electrical or electronic means (20) for determining the position of the actuator (18) or the push button (7) including a proportional sensor comprising, on the one hand, a mobile member (21) following the movement of the actuator (18) or a push button (7) and, on the other hand, a contactless means (22) for detecting the position of the mobile member (21) secured to the body (2), as well as an anti-tilting system, a load sensing system for controlling the pressure increase, the idling delivery of the heat engine, or a flow sharing system, comprising such a pressure regulating device (1).

Abstract: Disclosed is a hydraulic pump for construction machinery for controlling to inhibit one-way driving when compound-operating two-way driving and work devices, such as a boom, to enhance operation efficiency.

Abstract: Apparatus to increase a force of an actuator having an override apparatus are described herein. An example fluid control system includes a first fluid control apparatus to fluidly couple a control fluid supply source to a control actuator via a first passageway. The control fluid supply source provides a control fluid to move a control actuator member of the control actuator in a first direction or a second direction opposite the first direction when the control actuator is in the operational state. A second fluid control apparatus is in fluid communication with the first fluid control apparatus and is configured to fluidly couple an override actuator to the control actuator via a second passageway when the control actuator is in a non-operational state. The override actuator is operatively coupled to the control actuator.

Abstract: Construction equipment having an electric control lever is provided, which can intercept a control signal applied to a flow control valve when trouble occurs in the electric control lever or a control unit.

Abstract: A selector valve operating mechanism is provided with operating pistons which are hydraulic pistons connected through an operation link to a spool of a PTO selector valve, an solenoid valve for hydraulically controlling reciprocation of the operating pistons, and a controller which is a control device for transmitting an operation signal to the solenoid valve. Control of operation of the solenoid valve moves the spool through the operating pistons and the operation link to switch the PTO selector valve.

Abstract: A vehicle body inclination angle regulating unit (17) includes a balancing oil cylinder (10). One chamber of the balancing oil cylinder (10) is connected with an oil tank (5) and an oil source for leveling operation via a first one-way damper valve (8) and an electric controlled switch valve (7), and the other chamber of the balancing oil cylinder (10) is connected with a non-rod chamber of a suspension oil cylinder via an electric controlled shutoff valve (14) and a second one-way damper valve (9). In addition, an automatically-leveling hydropneumatic suspension mechanism includes at least two pairs of suspension oil cylinders (12), vehicle body inclination angle regulating units (17), a vehicle body transverse inclination angle sensor (1) and a control unit (3). Each suspension oil cylinder (12) is correspondingly provided with the vehicle body inclination angle regulating unit (17) including the balancing oil cylinder (10).

Abstract: An exemplary hydraulic system includes a digital valve operable to fluidly connect a hydraulic load to a pressure supply, and an orifice disposed in a flow path between the hydraulic load and the digital valve. A digital controller is operably connected to the digital valve. The digital controller stores a target pressure drop across the orifice and is configured to determine an actual pressure drop across the orifice and formulate a control signal based on the target pressure drop and the actual pressure drop. The controller transmits the control signal to the digital valve for controlling the operation of the valve.

Abstract: A liquid-operated actuator assembly includes a valve with an inlet for connection to a source of a liquid, a bi-stable electromagnetic device for operating the valve, and an actuator including a piston in a cylinder. The piston incorporates an actuating member. The cylinder has a chamber on one side of the piston to which the outlet of the valve is connected for receiving the liquid when the valve is opened in order to move the piston and the actuating member to an operative position. An electronic control circuit momentarily energizes the electromagnetic device for operation of the actuating member and to terminate operation of the actuating member.

Abstract: A system and method for operating a two-stage, high-pressure pumping system includes a low-pressure pump having an output configured to deliver a hydraulic fluid under a low-pressure at a high-volume to drive a tool associated with the two-stage, high-pressure, pumping system under low load conditions. The system also includes a high-pressure pump having an output configured to deliver the hydraulic fluid under a high-pressure at a low-volume to drive the tool under high load conditions. A pilot-operated device is included that is configured to selectively drive the tool with pressure from at least one of the output of the low-pressure pump and the output of the high-pressure pump. The pilot-operated device receives pilot pressure from the output of the low-pressure pump to control selectively driving the tool with the output of the two stage pump.

Abstract: There are provided: control valves 22-24 that control flow of pressure oil from the hydraulic source 21 to the hydraulic actuators 15-17; electric lever devices 51-53 that output electrical operation signals, which are drive instructions for the hydraulic actuators 15-17, in correspondence to lever operation; and a control unit 25-30 and 50 that controls the control valves 22-24 in correspondence to the operation signals. When the determination unit determines that an operation signal is not within the normal range, the hydraulic actuators 15-17 are allowed to be driven with flow of pressure oil to the hydraulic actuators 15-17 limited more significantly than in a case where it is decided that an operation signal is within the normal range.

Abstract: In an electro-pneumatic system for controlling a double-acting pneumatic actuator having first and second working chambers, first and second preliminary pneumatic control components generate first and second preliminary pneumatic control signals transferred to respective first and second main pneumatic control components having outputs connected to the respective first and second working chambers. An electronic splitter circuit precedes the first and second preliminary pneumatic control components for splitting and inverting an electrical control signal input to the splitter circuit around an electrical mean control value to create first and second mirror-inverted electrical control signals respectively connected to the respective first and second preliminary pneumatic control components.

Abstract: A testing apparatus is provided for opening and closing a door of an appliance being tested. The apparatus includes a framework; a first actuator attached to the framework, the first actuator having a retracted position and an extended position; a first attaching bar attached to the first actuator and to the door; and a controller for controlling the first actuator such that the first actuator causes the door to move to an open position when the actuator moves from a first one of the extended position and the retracted position to the other of the extended position and the retracted position, and the first actuator causes the door to move to a closed position when the actuator moves from the other of the extended position and the retracted position to the first one of the extended position and the retracted position.

Abstract: A pneumatic system controlling a bath crust breaker includes a cylinder defining a piston chamber. A piston is slideably displaced within the cylinder by pressurized fluid directed to either a piston chamber first portion with respect to the piston or a piston chamber second portion oppositely positioned about the piston. A pneumatic valve system includes a first control valve aligned between first control valve first and second positions, the first control valve first position aligned with the first portion, and in the first control valve second position is aligned with the second portion. A second control valve is aligned between second control valve first and second positions. An orifice between a pressure source and first control valve is sized to control fluid flow rate so a pressure reached in either the first or second portion during a crust breaking cycle is less than a pressure source maximum pressure.

Abstract: A method for operating a hydraulic actuation system during a pressure sensor malfunction is provided. The hydraulic actuation system includes a pump, a reservoir, a first work-port and a second work-port, a valve system with individual orifices, a pressure sensor system, and a controller for regulating the hydraulic actuation system based on fluid flow demand and on determined pressure differences. The method includes detecting a malfunction of a pressure sensor for the first work-port, closing second and third orifices, and regulating the pump to generate fluid flow corresponding to maximum pressure generated by the pump. The method also includes assigning a value for the difference between pump pressure and the pressure of the subject work-port that is equivalent to a value within an attainable range for difference between the two pressures. Furthermore, the method includes regulating a first orifice and a fourth orifice in response to the fluid flow demand.

Abstract: In a reciprocating piston compressor with delivery rate control, the electromagnetic actuating device (3) of the valve lifter (2) has a separate positioning drive (10) for adjusting the working stroke range of the magnetic actuator (5) used, whereby this can be chosen to be small and highly dynamic and only low power losses occur.

Abstract: A solenoid valve device includes: a solenoid valve that includes a solenoid that is supplied with driving current to generate magnetic flux, and a valve element that is moved by the magnetic flux generated from the solenoid; and a control device that controls the solenoid valve. The control device includes an alternating current component in the driving current and supplies the driving current including the alternating current component to the solenoid, and detects an impedance of the solenoid.

Abstract: A fluid power valve module has a supply port for fluid and at least one fluid power and more especially pneumatic valve able to be controlled via the control interface of the valve module for control of a fluid power instrumentality by way of power ports on the basis of the supplied fluid. There is a provision such that the valve module comprises at least one switching output integrated in its housing for output of a switching signal for switching a switching means for influencing and more especially deactivating the instrumentality.

Abstract: An adaptable hydraulic control system configured to be used with either open-center or closed-center hydraulic power systems which may include one or more switches, one or more hydraulic circuits to operate a sequence of motions and may include a shunt relief valve to permit operation with an open-center hydraulic innervator control valve(s) powered by wither an open-center system or a closed-center system. Series switches may control a sequence of operation by transitioning between different normal, or default states to act upon and control repositioning of a hydraulic innervator control valve(s) that may itself have normal or default states perhaps such as for forward operational flow, backward operational flow, or neutral pass through flow.

Abstract: A method of driving a hydraulic actuator provided with a pressure-controlled proportioning solenoid valve; the method includes the steps of: determining a first open-loop contribution according to a pressurized oil flow rate which crosses the proportioning solenoid valve and according to the desired load pressure inside the actuation chamber; determining a second open-loop contribution according to the desired position of the spool of the proportioning solenoid valve; determining a third closed-loop contribution according to the difference between a desired value of the position of the mobile piston and a real value of the position of the mobile piston; and calculating a desired electric driving current value of the proportioning solenoid valve by means of an algebraic sum of the three contributions.