The disclosure relates to a method for operating a hydraulic drive which comprises a hydraulic consumer with a positionable piston in a cylinder which is connected to a tank at one connection via a pump of variable rotational speed and at another connection via a proportional valve, wherein a position of the piston is controlled using a model-based control in which a rotational speed of the pump is used as a manipulated variable and in which a position of the proportional valve is preset.

A digital positioner for a valve includes a valve controller configured to obtain a set point value for a valve travel of a valve, and generate a pulse-width modulated current signal based on the set point value. The digital positioner also includes a current-to-pressure converter configured to receive the pulse-width modulated current signal from the valve controller, convert the pulse-width modulated current signal to a pulse-width modulated pressure signal, and provide the pulse-width modulated pressure signal to a pneumatic actuator in the valve to adjust a position of the valve.

A system and method that remotely monitors and controls proppant usage in a fracturing operation. The system and method allow operators to wirelessly monitor and control proppant storage units from inside a datavan through sensors and control mechanisms that interface with fracturing software to schedule the flow of the proppant. A sensor monitors the weight, container level, or volume of the proppant being used to keep the induced hydraulic fracture open. A serial to Ethernet converter converts this information and sends it wirelessly to a datavan. A user at the datavan controls the proppant usage through a display in the datavan of the storage units with the appropriate weight. The container monitoring software links with the fracturing software, providing real-time information about proppant usage so that the user can properly schedule proppant flow to the well through valves, conveyor belts, and other control mechanisms.

A system and method that remotely monitors and controls proppant usage in a fracturing operation. The system and method allow operators to wirelessly monitor and control proppant storage units from inside a datavan through sensors and control mechanisms that interface with fracturing software to schedule the flow of the proppant. A sensor monitors the weight, container level, or volume of the proppant being used to keep the induced hydraulic fracture open. A serial to Ethernet converter converts this information and sends it wirelessly to a datavan. A user at the datavan controls the proppant usage through a display in the datavan of the storage units with the appropriate weight. The container monitoring software links with the fracturing software, providing real-time information about proppant usage so that the user can properly schedule proppant flow to the well through valves, conveyor belts, and other control mechanisms.

A hydraulic control loop controls a hydraulic adjusting cylinder. The cylinder has a cylindrical housing and a displaceable piston therein. The piston divides the housing interior into a first and a second hydraulic chamber. A first hydraulic valve supplies the first hydraulic chamber with hydraulic fluid. A hydraulic pressure of the first hydraulic chamber is adjustable by controlling the first hydraulic valve. A second hydraulic valve supplies the second hydraulic chamber with hydraulic fluid. A hydraulic pressure of the second hydraulic chamber is adjustable by controlling the second hydraulic valve. A control device controls the two hydraulic valves. In a position control state, the second hydraulic valve is controlled by a position control signal dependent on the working position of the piston and the first hydraulic valve is controlled by an adjusted position control signal, that is generated on the basis of the position control signal.

A digital positioner for a valve includes a valve controller configured to obtain a set point value for a valve travel of a valve, and generate a pulse-width modulated current signal based on the set point value. The digital positioner also includes a current-to-pressure converter configured to receive the pulse-width modulated current signal from the valve controller, convert the pulse-width modulated current signal to a pulse-width modulated pressure signal, and provide the pulse-width modulated pressure signal to a pneumatic actuator in the valve to adjust a position of the valve.

A hydraulic control loop controls a hydraulic adjusting cylinder. The cylinder has a cylindrical housing and a displaceable piston therein. The piston divides the housing interior into a first and a second hydraulic chamber. A first hydraulic valve supplies the first hydraulic chamber with hydraulic fluid. A hydraulic pressure of the first hydraulic chamber is adjustable by controlling the first hydraulic valve. A second hydraulic valve supplies the second hydraulic chamber with hydraulic fluid. A hydraulic pressure of the second hydraulic chamber is adjustable by controlling the second hydraulic valve. A control device controls the two hydraulic valves. In a position control state, the second hydraulic valve is controlled by a position control signal dependent on the working position of the piston and the first hydraulic valve is controlled by an adjusted position control signal, that is generated on the basis of the position control signal.

The subject matter of this specification can be embodied in, among other things, a controller apparatus that includes a digital controller configured to provide a digital position signal based on a setpoint and a differential analog feedback signal, and a converter circuit configured to provide a differential analog electrohydraulic servo valve position control signal based on the digital position signal, and provide the differential analog feedback signal based on the differential analog electrohydraulic servo valve position control signal.

A method for optimally designing an irrigation system and managing/operating the designed irrigation system in real time comprising: •receiving data associated with a proposed irrigation design; •analysing the proposed design comprising one or more proposed measurements and automation requirements; •retrieving one or more pre-established estimation rules from a data store and mapping them with the proposed design; •estimating additional measurement and automation requirements based on one or more such estimation rules; •adjusting one or more estimation rules based on real data associated with operation of a previous/current irrigation system; •estimating one or more of acquisition, installation and operating costs based on one or more of: hardware costs; radio network propagation characteristics (optionally of terrain, crop, etc); other factors that have historically contributed to ownership cost; •displaying to a user one or more of such estimated costs; •calculating one or more alternative designs and displaying the associated information.

A method for optimally designing an irrigation system and managing/operating the designed irrigation system in real time comprising: •receiving data associated with a proposed irrigation design; •analysing the proposed design comprising one or more proposed measurements and automation requirements; •retrieving one or more pre-established estimation rules from a data store and mapping them with the proposed design; •estimating additional measurement and automation requirements based on one or more such estimation rules; •adjusting one or more estimation rules based on real data associated with operation of a previous/current irrigation system; •estimating one or more of acquisition, installation and operating costs based on one or more of: hardware costs; radio network propagation characteristics (optionally of terrain, crop, etc); other factors that have historically contributed to ownership cost; •displaying to a user one or more of such estimated costs; •calculating one or more alternative designs and displaying the associated information.