A system for controlling hydraulic fluid flow within a work vehicle includes a pilot conduit configured to receive a pilot flow of hydraulic fluid from a fluid supply conduit such that the operation of a compensator valve is controlled based on a pressure of the pilot flow within the pilot conduit. Furthermore, a pilot conduit valve is configured to adjust the pressure of the pilot flow within the pilot conduit. In addition, the system includes a load sense conduit configured to receive a bleed flow of the hydraulic from the fluid supply conduit such that the operation of the pump is controlled based on a pressure of the bleed flow within the load sense conduit. Moreover, a load sense valve is configured to adjust the pressure of the bleed flow within the load sense conduit.

A robotic device may traverse a path in a direction of locomotion. Sensor data indicative of one or more physical features of the environment in the direction of locomotion may be received. The implementation may further involve determining that traversing the path involves traversing the one or more physical features of the environment. Based on the sensor data indicative of the one or more physical features of the environment in the direction of locomotion, a hydraulic pressure to supply to the one or more hydraulic actuators to traverse the one or more physical features of the environment may be predicted. Before traversing the one or more physical features of the environment, the hydraulic drive system may adjust pressure of supplied hydraulic fluid from the first pressure to the predicted hydraulic pressure.

An auxiliary power unit system for mobile service vehicles is provided that can provide DC power to DC-powered equipment. The system attaches to the power take-off port of the transmission and can provide power to the DC-powered equipment without idling the engine of the mobile service vehicle, thereby reducing fossil fuel consumption and engine exhaust emissions.

A method and control system operable to control movement of a work implement of a work vehicle. The control system includes a reservoir that retains fluid, a pump in fluid communication with the reservoir, and an actuator in fluid communication with the pump. The actuator has a first side and a second side. A control valve is fluidly positioned between the pump and the actuator, a first proportional relief valve is fluidly positioned between the pump and the first side of the actuator, and a second proportional relief valve is fluidly positioned between the pump and the second side of the actuator. The first proportional relief valve is configured to permit flow of fluid from the first side of the actuator to the reservoir when a pressure at the first side of the actuator exceeds a pressure set point.

A hydraulic device 10 includes a hydraulic pump 20, a tool 70, an oil passage 30, 32, 50, 52 for sending the pressure oil generated by the hydraulic pump 20 to the tool 70 and returning return oil from the tool 70 to the hydraulic pump 20, a handle 90 configured to be held by one hand of a worker, a switching part 88 disposed at the oil passage 30, 32, 50, 52 and configured to switch a path for at least one of the pressure oil and the return oil, and an operation part 80 for operating the switching part 88. The operation part 80 is disposed at a position that allows the operation part 80 to be operated with the hand of the worker holding the handle 90, or with a finger of the hand holding the handle 90.

Methods of controlling an actuator during operation using a hydraulic circuit, and related apparatus, are described. The circuit has a first path section along which fluid is supplied to a first chamber of the actuator using a first valve and a second path section along which fluid is extracted from a second chamber of the actuator using a second valve. Pressure data associated with a pressure of the fluid supplied to the first side of the actuator are obtained, a pilot pressure pPilot is produced based on the data and the first and second valves are configured based on the pilot pressure pPilot.

Provided are hydraulic systems comprising variable speed drives coupled to hydraulic pumps and methods of operating such systems. The drive speed is controlled based on the position of a hydraulic servo-control valve in order to reduce the flow through a bypass line. Specifically, the drive speed may be decreased as the valve is opening and sending a greater portion of the hydraulic fluid into the bypass line. This approach allows to reducing losses in the bypass line thereby increasing the overall efficiency of the hydraulic system. The position of the hydraulic servo-control valve may be determined using a position sensor or a flow sensor. Alternatively, the position may be estimated by increasing the drive speed and monitoring the pressure change in the hydraulic actuator. The differential pressure-speed ratio obtained during this speed increase is compared to a calibration set of values corresponding to different valve positions.

A work vehicle includes a valve for switching between a merging position for causing a first oil passage for driving a bucket and a second oil passage for driving an arm to communicate with each other, and a diverging position for separating the first oil passage and the second oil passage. The work vehicle is adapted to switch the valve from the merging position to the diverging position, when one of a pump pressure in the first pump and a pump pressure in the second pump comes to be equal to a predetermined value during an excavation operation. The work vehicle is adapted to control both pumps, such that the amount of the oil discharged from the first pump is larger than the amount of the oil discharged from the second pump, when the pump pressure in the first pump is equal to or more than the predetermined value.

A system, including: a fluidic actuator which can be acted upon by a pressurized fluid and has an actuator member, a pressurized fluid provision device which is adapted to carry out a position control of the actuator member and, within the position control, to act upon the fluidic actuator with the pressurized fluid in order to move the actuator member into a prescribed position, and a hose arrangement, including at least one hose via which the fluidic actuator is fluidically connected to the pressurized fluid provision device, wherein the pressurized fluid provision device is adapted to carry out the position control taking into account a system model describing the hose arrangement, the actuator and/or the pressurized fluid provision device.

A servo-control. The servo-control comprises at least one body as well as a power shaft and a control piston arranged in each body, the at least one body and the power shaft respectively forming two power members. One of the power members bears at least on end-stop member and the power member without an end-stop member bears a passivation actuator. The passivation actuator comprises a passivation shaft which bears an end-stop and a passivation piston, the passivation piston being arranged to be mobile in longitudinal translation in an enclosure, an elastic system being arranged between the passivation piston and the enclosure.