A hydraulic system controller is disclosed. The hydraulic system controller may determine a maximum active circuit pressure of a set of active hydraulic circuits of the hydraulic system, wherein the hydraulic system includes a hydraulic pump to cause fluid to flow throughout the set of active hydraulic circuits; determine a circuit pressure of a hydraulic circuit of the hydraulic system; determine, based on a hydraulic flow command for the hydraulic circuit and the circuit pressure, a desired circuit delta-pressure for the hydraulic circuit; determine, based on the desired circuit delta-pressure and a pressure difference between the maximum active circuit pressure and the circuit pressure, a circuit valve setting for a circuit valve of the hydraulic circuit; and cause a control device to set a position of the circuit valve according to the circuit valve setting.

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 first required flow rate is calculated as a function of a first maximum allowable flow rate and a value of a first signal. A second required flow rate is calculated as a function of a value of the second signal. When the first maximum allowable flow rate is higher than a first capacity, the value of the first signal is a maximum level, and the value of the second signal is equal to or higher than a minimum level and equal to or lower than a maximum level, a first working fluid supply is controlled to discharge working fluid at a flow rate equal to the first capacity, and a second working fluid supply is controlled to discharge working fluid at a flow rate obtained by deducting the first capacity from the first maximum allowable flow rate, added to the second required flow rate.

Target speeds of an arm cylinder and a boom cylinder are computed in response to a distance D between a bucket tip end and a target surface in such a manner that an operating range of a work device is limited on and above the target surface at a time of operating an operation device. A second flow control valve that supplies a hydraulic operating fluid from a second hydraulic pump to the boom cylinder is controlled on the basis of the target speed of the boom cylinder while a first flow control valve that supplies a hydraulic operating fluid from a first hydraulic pump to the arm cylinder and a third flow control valve that supplies the hydraulic operating fluid from the second hydraulic pump to the arm cylinder are controlled on the basis of the target speed of the arm cylinder.

A fluidic logic and actuator system for outputting a displacement having a fluidic logic circuitry layer including a fluidic control input and a plurality of fluidic latching memory units. At least some of the plurality of fluidic latching memory units are configured to perform combinatorial and sequential logic functions and output a fluid response. A fluid actuator layer is provided having a plurality of fluid actuators, wherein each of the plurality of fluid actuators being movable in response to the fluid response of a corresponding one of the plurality of fluidic latching memory units.

A operator supporting electrohydraulic drive and control system based on, position sensors (8) (9), a electronic control unite ECU (2), a recovery, storing and re-use system for energy, and with actuator (3) (4) and the drive control valve (6) (7) bolted together in one (3+6) (4+7) unite and with the valve (6) (7) independently of the ECU (2) is controlling effective use of pump capacity and recovery of energy and with control of speed for low speeds, or prevented speed by valves (6) (7) or pump (10) (10a) (11) (11a) displacement and for higher speed with control of deplacement of pumps and motors and with valves (6) (7) at the same time controlled to be fully open.

A work machine includes directional control valves 43 and 44 each controlling a direction and a flow rate of a pressurized fluid supplied to each a boom cylinder 32 and a bucket cylinder 36; operation amount sensors 51a, 52a, and 52b detecting operation amounts of operation devices 51 and 52; a variable flow control valve 45 that can restrict the flow rate of the pressurized fluid in a meter-in passage of the directional control valve 44 related to the bucket cylinder 36; and a controller 60 controlling the variable flow control valve on the basis of the detection results by the operation amounts from the operation amount sensors, and the controller changes over an action mode to any one of a normal mode for restricting the flow rate of the pressurized fluid by the variable flow control valve and a responsiveness priority mode for not restricting the flow rate of the pressurized fluid by the variable flow control valve in response to the detection results of the operation amounts of the plurality of operation devices. It is thereby possible to enhance responsiveness in an action that requires responsiveness such as an action in which an operation amount of an operation lever frequently changes in a short period of time and to suppress a decline in work efficiency.

A hydraulic system controller is disclosed. The hydraulic system controller may determine a maximum active circuit pressure of a set of active hydraulic circuits of the hydraulic system, wherein the hydraulic system includes a hydraulic pump to cause fluid to flow throughout the set of active hydraulic circuits; determine a circuit pressure of a hydraulic circuit of the hydraulic system; determine, based on a hydraulic flow command for the hydraulic circuit and the circuit pressure, a desired circuit delta-pressure for the hydraulic circuit; determine, based on the desired circuit delta-pressure and a pressure difference between the maximum active circuit pressure and the circuit pressure, a circuit valve setting for a circuit valve of the hydraulic circuit; and cause a control device to set a position of the circuit valve according to the circuit valve setting.

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 hydraulic drive device for an industrial vehicle includes a tank, a hydraulic pump, a capacity control valve, a plurality of hydraulic cylinders, a plurality of direction switching valves, a first hydraulic oil passage, a second hydraulic oil passages, a pilot line, a relief valve, a relief pressure setting portion, a plurality of operation detecting portions, and a control unit. The control valve controls the hydraulic pumps so that a differential pressure between a discharge pressure of the hydraulic pump and a pilot pressure of the pilot line is to be a predetermined pressure. The control unit controls the relief pressure setting portion.