A method of monitoring a fluid system of a mining machine. The method including sensing a pressure level of a fluid in the fluid system of the mining machine to generate pressure level data; analyzing the pressure level data to detect pressure level deviations; determining at least one selected from the group of when a frequency of the pressure level deviations exceeds a predetermined frequency, and when the fluid pressure level fails to reach a threshold within a predetermined reaction time period; and outputting an alert in response to the determination.

A multi-pressure hydraulic control system (66, 166, 266) for use with a continuously variable automatic transmission (14) of a vehicle powertrain system (10) includes at least one pump (28) having a rotatable pump member (34), at least one inlet region (40) for receiving fluid to be pumped by the pump member (34), and at least one outlet region (42) for outputting fluid pumped by the pump member (34), and a switching valve (78, 178, 278) receiving at least two separate outputs (42) of fluid pumped by the at least one pump (28) for allowing the at least two outputs to be selectively combined and/or separated, the switching valve (78, 178, 278) having a valve member (79, 179, 279) being movable between at least three positions that produces fluid outputs having a first fluid pressure, a second fluid pressure, and a third fluid pressure to one or more portions of the continuously variable automatic transmission (14).

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.

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.

An abnormality detection device for a hydraulic circuit including an oil pump capable of increasing oil a suction port and discharging the oil through discharge ports; a switching unit that switches between fully and partially discharged states; a pressure regulation unit that regulates an oil pressure; and a hydraulic pressure detection unit that detects the oil pressure includes: a storage unit that stores a maximum discharge pressure in the partially discharged state; a switching control unit that switches to either one of the discharged states; a pressure regulation control unit that sets a target pressure higher than the maximum discharge pressure in the partially discharged state, and performs pressure regulation control to achieve the target pressure; and a determination unit that determines whether the switching unit has a fixation abnormality in one of the discharged states by comparing a hydraulic pressure with the maximum discharge pressure in the partially discharged state.

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.

The present invention provides a controller for a pendulum type wave-power generating apparatus. Electric power produced by wave-power generation has been pointed out as being of low efficiency and more expensive than wind-power generation. To overcome the above problems, the present invention uses resonance and impedance matching of the sea waves, thus making it possible to markedly enhance the efficiency of wave-power generation. The present invention does not use a wave-height meter which is generally expensive and controls the generating apparatus in response to variation of the conditions of the sea, thus automatically maintaining the resonance and impedance matching operation, thereby making high-efficiency operation possible. As a result, the cost of the wave-power generation can be reduced, so that the wave-power generation can be widely commercialized.

A hydraulic circuit for a lift truck comprises a feed-through cylinder communicating with a free lift cylinder and a lift cylinder.

A refuse vehicle can include a first element, a hydraulic system, and one or more processing circuits. The one or more processing circuits can receive a first input to control the first element to cause the first element to perform a first operation of the refuse vehicle, obtain first information to indicate a metric associated with an energy source of the hydraulic system, determine that a first amount of fluid power exceeds a fluid power threshold for the hydraulic system, and modify the first input to reduce a request from the first amount of fluid power to a second amount of fluid power.