A system and method for detecting faults and optimiz-ing power usage of solenoid valves. The method includes obtaining a current signature of the solenoid coil, using a dedicated circuit to detect various features and using a pulse width modulation controller optimize the power output of the system. Additionally, using machine learning, the system can be optimized using data from the dedicated circuit.

A milling machine may have a frame, ground engaging tracks that support the frame, and an actuator that adjusts a height of the frame relative to the track. The milling machine may have a control valve that selectively controls a flow of fluid into or out of the actuator based on the current supplied to the control valve. The milling machine may have a controller that determines the amount of current required to operate the actuator at a nominal actuator velocity and supplies that current to the control valve. The controller determines a measured actuator velocity based on a time required to extend or retract the actuator by a predetermined length, and adjusts the amount of current based on the measured and nominal actuator velocities. The controller also supplies the adjusted amount of current to the control valve to adjust the height of the frame relative to the track.

A system including a pneumatic actuator having an actuator element, the system further including a compressed-air provision device which is configured to carry out a closed-loop position control of the actuator element by applying compressed air to the pneumatic actuator. The compressed-air provision device is further configured to carry out an assistance procedure in which the actuator element is set in an oscillation movement, pressure values and position values are detected, and, on the basis of the detected pressure values and the detected position values, friction information and/or mass information is determined and/or verified.

A sensor system for a dual bottle accumulator utilized with a subsea blowout preventer that monitors piston position with a position sensor in the hydraulic bottle, the gas pressure in the associated gas bottle with one or more pressure sensors, and sensors and remote actuators for associated valves.

A counter pressure valve arrangement for controlling a pressure level of a hydraulic fluid in a return line from a hydraulic actuator arrangement. The counter pressure valve arrangement comprises a counter pressure valve having: a moveable valve member; a counter pressure regulating port configured for being connected to the hydraulic actuator arrangement via the return line; a tank port configured for being connected to a tank or low pressure reservoir for storing low pressure hydraulic fluid; and a pump port configured for being connected to a source of pressurised hydraulic fluid. A first position of the valve member effects fluid communication between the pump port and the counter pressure regulating port for supplying pressurised hydraulic fluid to the return line, and a second position of the valve member effects fluid communication between the counter pressure regulating port and the tank port for discharging hydraulic fluid from the return line to the tank.

A milling machine may have a frame, a milling drum attached to the frame, and ground engaging tracks that support the frame and propel the milling machine in a forward or rearward direction. The milling machine may have height adjustable actuators connecting the frame to the tracks. Each actuator may have a cylinder attached to the frame, a piston slidably disposed within the cylinder, and a rod connected at a first end to the piston and connected to a track at a second end. The milling machine may have a tank storing hydraulic fluid and a fluid conduit connecting the tank to the cylinder. The milling machine may have a control valve selectively controlling a flow rate of the hydraulic fluid in the fluid conduit. The milling machine may also have a controller that determines a height of the frame relative to the ground surface based on the flow rate.

A method for operating a fluid system including the steps: receiving or determining a set value for a stroke of the working valve, determining an actual value for the stroke of the working valve using a sensor signal of a position sensor, determining a deviation value of a working valve in dependence on sensor signals of a supply pressure sensor and a working pressure sensor and a position sensor and a sensor system, and performing a processing of the set value for the stroke of the working valve, the actual value for the stroke of the working valve and the deviation value to a control signal for driving the working valve.

A regeneration device includes: a regeneration valve that controls the flow rate of an operating fluid being drained from one port of a cylinder; a non-return valve that allows a regenerative flow of the operating fluid from the regeneration valve to the other port of the cylinder and blocks an opposite flow of the operating fluid; and an exhaust valve that controls the flow rate of the operating fluid output from the regeneration valve being drained to a tank. The regeneration valve controls the flow rate independently of the exhaust valve.

The subject matter of this specification can be embodied in, among other things, an electrohydraulic positioning control system that includes a shuttle valve configured to direct fluid flow between a selectable one of a first fluid port and a second fluid port, and a fluid outlet configured to be fluidically connected to a fluid actuator, a first servo valve controllable to selectably permit and block flow between the first fluid port, a fluid source, and a fluid drain, a second servo valve controllable to selectably permit and block flow between the second fluid port, the fluid source, and the fluid drain, a first servo controller configured to provide a first health signal and control the first servo valve based on a second health signal, and a second servo controller configured to provide the second health signal and control the second servo valve based on the first health signal.

A safety module for a process valve and a system comprising a safety module and a process valve are provided. The safety module comprises at least a first interface complementary to a first connection interface of a drive module of the process valve and a second interface complementary to a second connection interface of a process valve actuator of the process valve, such that the safety module can be retrofitted in the process valve. The safety module further comprises at least one safety valve and fluid lines provided for fluidically coupling the safety valve to the drive module and the process valve actuator of the process valve. The at least one safety valve of the safety module is configured for forced venting of the process valve in a safety case.