Systems and methods for estimating the area ratio of an actuator in static and dynamic states are disclosed. In one aspect, a metering valve is connected to each side of the actuator. In one example, one metering valve is held closed while the other metering valve incrementally pressurizes the actuator in discrete steps. The resulting work port pressures can be used to determine the actuator area ratio. Where counterbalance valves are installed in the system, the pressurizing metering valve can be placed in a pressure control mode to obtain the desired pressure values. In one example, the ratio of flows through each metering valve is used to determine the actuator ratio.

A cylinder positioning system (1) comprising a control unit for a pneumatically driven cylinder (14) in a cylinder chamber is provided. The control unit comprising a controller configured to control a set of drive units of the cylinder positioning system. Each drive unit emits a drive current to a respective electromagnetic direct acting valve (9,10, 11, 12) of the cylinder positioning system. Each respective electromagnetic direct acting valve has a closing/opening time of less than 2 ms. The control unit is configured to receive a set position for the cylinder and an actual position for the cylinder, to compare the set position of the cylinder with the actual position of the cylinder and to emit control signals to the drive units to move the cylinder from the actual position towards the set position. By providing a very short time for actuation of the valves, in combination with an actual position for the cylinder a closed loop control can be achieved to control the flow to the actuating cylinder to be proportional over essentially the entire dynamic range of the pneumatic position control system. This in turn can make the control more accurate and robust and with smaller latency.

An actuator arrangement, having a drive for providing a rotational movement about an axis of rotation and which includes an actuator housing whose outer surface extends with a curved profiling along the axis of rotation and which delimits a working space, in which a working element is rotatably accommodated, which includes a drive shaft which penetrates a front surface of the actuator housing, wherein the actuator housing is penetrated by a working port, which is designed for a connection of the working space with a valve arrangement, and with a valve arrangement, which is designed for a provision of a fluid flow at the working port and which includes a valve module, which is accommodated in a valve shaft of a valve housing and which has a fluid port, wherein the valve housing extends with a profiling in the form of a circular ring section along the axis of rotation.

Systems and methods for controlling valve assemblies associated with an actuator in an electro-hydraulic system are disclosed. In one method, a controller monitors hydraulic fluid flow for an actuator to identify one valve assembly connected to the actuator as a meter-in valve and another valve assembly connected to the actuator as a meter-out valve. In one aspect, the valve assembly most recently identified as the meter-in valve is controlled to maintain a pressure setpoint and the valve assembly most recently identified as the meter-out valve is controlled to maintain a hydraulic fluid flow rate. The method can also include determining whether the actuator is in a passive state or an overrunning state and controlling the valve most recently identified as the meter-in valve to maintain a first pressure setpoint when the actuator is in a passive state and to maintain a second pressure setpoint when the actuator is in an overrunning state.

An electro-pneumatic controller includes a base having a body, a top surface, and a bore formed within the body; a cover coupled to the base, the cover having an open end with a rim, the rim contacting the top surface of the base; a plurality of fluid flow paths formed within the base; and at least one flame arrestor disposed within one of the fluid flow paths.

A ride control system includes four independent metering valves (IMVs) that are independently and selectively controlled by a controller for attenuating oscillations in a hydraulic actuator of a machine. The controller is configured to open at least one of the IMVs for supplying pressurized fluid from a tank to a head end chamber of the hydraulic actuator when a pressure of the head end chamber drops to a value less than an initially registered pressure. Additionally, when the displacement of the piston block is positive and the pressure in the head end chamber falls to a value less than the pressure of fluid in a rod end chamber of the hydraulic actuator, the controller may also open another one of the IMVs by which fluid from the rod end chamber could be supplied to the head end chamber for supplementing pump flow and attenuating oscillations in the hydraulic actuator.

A method for operating a valve device for supplying compressed air to compressed air consumer includes the method comprising the steps of: determination of a first fluid pressure in a first section of a fluid passage of a valve assembly, which extends between an inlet port, and a valve element, determination of a second fluid pressure in a second section of the fluid passage of the valve assembly, which extends between the valve element and an outlet port, determination of a flow value for the valve element from the two fluid pressures and of a flow function, relating of the flow value with a presettable volumetric fluid flow rate or mass fluid flow rate for the pressurised fluid, which flow rate is provided for flow through the fluid passage, to a guide value and determination of a required actuating energy for an actuating device, and provision of the actuating energy to the actuating device.

The present invention relates to a hydraulic valve arrangement for controlling/regulating at least one hydraulic consumer of a mobile machine, with a summation interconnection of at least two hydraulic valves and at least one consumer interconnection of hydraulic valves, wherein the outputs of the summation interconnection are hydraulically connected with the inputs of the consumer interconnection, wherein at least one backflow valve is provided in the consumer interconnection. According to the invention, the at least one backflow valve for throttling a consumer return volume flow opens or closes in dependence on a consumer inflow pressure and comprises at least one main piston arranged in a bushing and at least two further pistons arranged in a lid separate from the bushing, wherein the main piston and the control piston interact with each other via a compression spring.

A method for the supply of compressed air of a compressed-air consumer having two fluidically separate, kinematically coupled working areas, wherein each of the working areas is assigned to a valve arrangement which can be independently controlled and can be configured between a blocking position, a first functional position for a fluidically communicating connection to a fluid course and a second functional position for a fluidically communicating connection to a fluid sink and wherein each of the two valve arrangements is configured individually depending on a predefinable movement task for the compressed-air consumer and depending, on at least two pressure values from the following group: supply pressure, first working area pressure, second working area pressure, discharge pressure, for a provision of a predefinable developing for a fluid mass flow or for a provision of a predefinable developing for a fluid pressure in the respective working area or for a provision of a predefinable developing of a valve cross-section.

An electronic execution unit controls and regulates a pneumatic valve assembly for a pneumatic movement. An application for controlling and regulating a valve assembly is or can be loaded so that it can be carried out on the electronic execution unit to carry out the pneumatic movement on the pneumatic valve assembly. An electronic valve controller for the open-loop control and closed-loop control of a valve assembly has at least one pneumatic valve for a pneumatic movement task.