A hydraulic valve assembly includes an algorithm stored in an internal memory of the hydraulic valve assembly that determines a spool correction command based on a flow demand which is calculated for obtaining a target single port pressure or a target delta pressure using one or more port pressure measurements. The spool correction command is sent to an upper level controller of the hydraulic valve assembly, and the upper level controller uses the spool correction command to obtain an optimal displacement of a spool inside the valve assembly.

An actuation pressure to actuate one or more hydraulic actuators may be determined based on a load on the one or more hydraulic actuators of a robotic device. Based on the determined actuation pressure, a pressure rail from among a set of pressure rails at respective pressures may be selected. One or more valves may connect the selected pressure rail to a metering valve. The hydraulic drive system may operate in a discrete mode in which the metering valve opens such that hydraulic fluid flows from the selected pressure rail through the metering valve to the one or more hydraulic actuators at approximately the supply pressure. Responsive to a control state of the robotic device, the hydraulic drive system may operate in a continuous mode in which the metering valve throttles the hydraulic fluid such that the supply pressure is reduced to the determined actuation pressure.

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.

One object is to calculate the position of a rod of a linear actuator with a high precision. The linear actuator includes a rod capable of moving in an axial direction relative to a housing. The rod is moved by rotation of an output shaft of a motor. A position sensor for sensing the relative position of the rod relative to a preset reference position is provided in the housing. A rotation sensor for sensing the rotation angle of the output shaft of the motor is provided in the vicinity of the motor. The linear actuator includes a position calculating unit for calculating the position of the rod based on a position sensing value of the position sensor and a rotation angle sensing value of the rotation sensor.

A support apparatus is equipped with a support foot of hydraulic type that comprises: a cylinder equipped with a cavity axially shaped that has a longitudinal axis, a piston slidably received in a sealed manner in the cavity so as to divide said cavity into a first chamber and a second chamber, a stem provided with a first end fixedly connected to the piston and a second end that protrudes from the cylinder, a base fixed to the second end of the stem, and an actuation group of the support foot configured to selectively send a pressurised work fluid to the first chamber or to the second chamber so as to change the relative position of the base with respect to the cylinder. Where said support apparatus comprises: a position sensor configured to monitor the value of a parameter indicative of the position of the base with respect to a reference element fixedly connected to the cylinder, and an electronic control unit, electrically connected to said position sensor, which is configured to transmit the value of the indicative parameter monitored by the position sensor to a remote device and to control the activation of the actuation group of the support foot as a function of an activation signal and the value of the indicative parameter.

Concrete product machine apron gap adjustment by actuating a gapper mechanism to set a desired gap between a reciprocally-movable apron plate and an interchangeably installable mold assembly installed in a concrete products machine. The gapper mechanism sets a desired gap between the machine apron plate and the mold assembly by injecting an index amount of hydraulic fluid into fluid communication with the rod side of a primary apron plate positioning cylinder, causing the machine's apron plate to retreat a desired gap distance away from an engaged position against the mold assembly.

A rephasing system may include a first hydraulic cylinder, a second hydraulic cylinder, a first rephasing valve, a second rephasing valve and a controller. The first hydraulic cylinder and the second hydraulic cylinder include first and second pistons, respectively. A first hydraulic fluid line connects a hydraulic supply to a first side of the first piston while a second hydraulic fluid line connects a second side of the first piston to a first side of the second piston. The first rephasing valve fluidly couples the first side of the first piston to the first side of the second piston while the second hydraulic fluid line fluidly couples the second side of the second piston to the hydraulic supply. The controller selectively opens and closes the first and second rephasing valves to re-phase the first and second pistons.

A system (100), including: a fluidic actuator (2) which can be acted upon by a pressurized fluid and has an actuator member (3), a pressurized fluid provision device (4) which is adapted to carry out a position control of the actuator member (3) and, within the position control, to apply the pressurized fluid to the fluidic actuator (2) in order to move the actuator (3) into a prescribed position, the pressurized fluid provision device (4) being adapted to carry out the position control taking into account at least one system parameter, which describes a physical property of the system and/or a requirement parameter which defines a requirement for the positioning of the actuator (3), wherein the pressurized fluid provision device (4) is further adapted to perform an assistance procedure and to determine and/or verify, within the assistance procedure, the system parameter and/or the requirement parameter on the basis of a movement of the actuator (3) and/or a consideration of physical limits.

A hydraulic system may include an electrohydraulic control valve disposed in fluid communication between a source of pressured fluid and a hydraulic actuator. The hydraulic system may be controlled to correct for offset errors between a target actuator pressure and a current actuator pressure output from the control valve, without amplifying pressure oscillations in the fluid between the control valve and the hydraulic actuator.

Systems and methods are provided for a hydraulic stabilizer trim actuator (HSTA). The HSTA may operate one or more movable control surfaces. The HSTA operate responsive to commands issued by the pilot and/or by a controller and may include hydraulic architecture that minimizes the probability of an un-commanded movement or movement in the opposite direction of such commands