A mobile hydraulic system includes a hydraulic actuator coupled to a load, and a control unit coupled to the load and/or to the hydraulic actuator. The control unit is adapted to anticipate an over-center transition of the load relative to a gravity vector prior to the over-center transition through the use of sensors configured with accelerometers, gyroscopes and magnetometers. In some examples, the over-center transition is from an overrunning driving of the load to a passive driving of the load. In some examples, the over-center transition is from a passive driving of the load to an overrunning driving of the load. In some examples, the control unit is adapted to control change in a metered flow through one or more ports of the associated actuator to minimize and/or prevent one or more hydraulic effects of the anticipated over-center transition. In some examples, the control unit controls the metered flow by causing one or more actuators (e.g., a solenoid) to shift one or more valve positions to change the flow through one or more ports of the associated actuator.

A system including a pneumatic actuator with an actuator member and a compressed air supply device which is configured to apply compressed air to the pneumatic actuator in order to set the actuator member in an actuator member movement towards an end position of the pneumatic actuator, wherein the compressed air supply device is further configured to provide an end position damping for the actuator member movement and, during the end position damping, to adjust a conductance value of a discharge valve, via which the compressed air supply device discharges compressed air from a pressure chamber of the pneumatic actuator which pressure chamber counteracts the actuator member movement, in accordance with a conductance characteristic in dependence of a driving force acting on the actuator member.

An adjustable ride control circuit and method that includes a head valve that controls flow between a boom cylinder head intake and an accumulator, and a rod float valve that controls flow between a boom cylinder rod intake and tank, where the rod float valve is electronically adjustable and proportionally controls flow restriction. A controller controls ride control activation, and adjustment of the head and rod float valves. When ride control is activated, the head valve allows flow between the head intake and the accumulator, and the controller automatically adjusts the rod float valve. When ride control is deactivated, the head valve blocks flow between the head intake and the accumulator, and the rod float valve blocks flow between the rod intake and tank. An enable valve can control positioning of the head valve. A flow selector can select manual or automatic adjustment of the rod float valve.

A solenoid flow control valve includes: an inlet passage that allows an inlet port to communicate with a pilot pressure chamber; an outlet passage that allows the pilot pressure chamber to communicate with an outlet port; a fixed restrictor provided on the outlet passage; a pilot spool that closes the inlet passage when a solenoid is in a non-excitation state, whereas when solenoid is in an excitation state, opens inlet passage at an opening degree corresponding to an input current value to generate a pilot pressure corresponding to the input current value in pilot pressure chamber, the pilot spool opening a bypass passage when input current value is less and closes bypass passage when input current value is greater than or equal to the predetermined value; and a main spool that controls a flow rate from inlet to outlet port in accordance with the pilot pressure chamber's pilot pressure.

An implement includes a mechanical coupling component configured to removably couple the implement to a support machine, a hydraulic fluid supply line configured to receive a supply flow of hydraulic fluid under pressure from a hydraulic system associated with the support machine, and a hydraulically-powered component configured to be actuated using the hydraulic fluid. The implement also includes a hydraulic fluid recovery system comprising a hydraulic fluid return line configured to fluidically couple to the hydraulic system associated with the support machine and provide a return flow of hydraulic fluid to the hydraulic system. A hydraulic fluid reservoir is configured to, when the hydraulic fluid return line is decoupled from the hydraulic system associated with the support machine, receive a portion of the hydraulic fluid from the hydraulic fluid return line when a fluid pressure in the hydraulic fluid return line increases to a pressure threshold.

An example robot includes a hydraulic actuator cylinder controlling motion of a member of the robot. The hydraulic actuator cylinder comprises a piston, a first chamber, and a second chamber. A valve system controls hydraulic fluid flow between a hydraulic supply line of pressurized hydraulic fluid, the first and second chambers, and a return line. A controller may provide a first signal to the valve system so as to begin moving the piston based on a trajectory comprising moving in a forward direction, stopping, and moving in a reverse direction. The controller may provide a second signal to the valve system so as to cause the piston to override the trajectory as it moves in the forward direction and stop at a given position, and then provide a third signal to the valve system so as to resume moving the piston in the reverse direction based on the trajectory.

A system including a pneumatic actuator with an actuator member and a compressed air supply device which is configured to apply compressed air to the pneumatic actuator in order to set the actuator member in an actuator member movement towards an end position of the pneumatic actuator, wherein the compressed air supply device is further configured to provide an end position damping for the actuator member movement and, during the end position damping, to adjust a conductance value of a discharge valve, via which the compressed air supply device discharges compressed air from a pressure chamber of the pneumatic actuator which pressure chamber counteracts the actuator member movement, in accordance with a conductance characteristic in dependence of a driving force acting on the actuator member.

A control arrangement (5) of a hydraulic system (1) is provided, said control arrangement (5) comprising a supply port arrangement having a high pressure port (6) and a low pressure port (7), a working port arrangement having two working ports (8, 9), a first valve (10) arranged between said high pressure port (6) and said working port arrangement (8, 9), a second valve (11) arranged between said low pressure port (7) and said working port arrangement (8, 9). Such a control arrangement should enhance the control of a hydraulic system. To this end a controller (16) is provided for controlling said first valve (10) and said second valve (11), said controller (16) has an input connection (17) for receiving a signal of an operator input device and on the basis of said signal said controller at least initially calculates an unbalance between a first flow demand for said first valve (10) and a second flow demand for said second valve (11), and adjusts said first valve (10) according to said first flow demand and said second valve (11) according to said second flow demand.

A construction machine that precisely enables derivation of the operation characteristics of hydraulic actuators in a high-velocity area with less calibration operation is provided. A controller (10) has a calibration mode in which the controller (10) derives operation characteristics (α(xs)) representing a relation among a spool position (xs) of a meter-in valve (8a1), an operation velocity (Va) of a hydraulic actuator (4a), and a differential pressure (ΔP) across the meter-in valve (8a1), and is configured to, in a case where the spool position (xs) of the meter-in valve (8a1) has changed in a direction to increase the opening area of the meter-in valve (8a1) in the calibration mode, output a command signal to increase the opening area of a bleed-off valve (8b1) to a bleed-off solenoid proportional pressure-reducing valve (8b2) as a command signal to reduce the differential pressure (ΔP).

A hydraulic circuit having a function of compensation and energy recovery comprises a distribution module, a three-way compensated regulator device, a variable flow rate or pressure feeding assembly, an energy recovery device connected to the three-way compensated regulator device. The distribution module comprises a spool including an inlet recess and a drain recess configured so that the flow rate of fluid inlet to the utility is equal to or less than the one outlet therefrom, possibly net of a correction factor. There is also a respective first driving channel and a second driving channel configured so that a pressure taken upstream of the drain recess acts on a first side of the regulator device, and so that a pressure taken downstream of the drain recess in the first channel acts on a second side of the regulator device, and an additional force.