Apparatus and methods for controlling a hydraulic cylinder with a control valve in a control system. The control system comprises a voltage level shifter that produces a shift reference voltage (SHRv) substantially equal to the fraction value of a valve power supply voltage (VPSv). A controller produces a control system output voltage (CNTo) with a positive value, a negative value, or a zero value in response to a control input voltage (CNTi) and the VPSv. A voltage converter receives the SHRv and CNTo, and provides a control signal input voltage (CSi) to the control valve. The CSi is greater than the fraction value of the VPSv when the CNTo is the positive value, less than the fraction value of the VPSv when the CNTo is the negative value, and substantially equal to the fraction value of the VPSv when the CNTo is the zero value.

The present disclosure describes a control system network architecture for a fluidic control system such as a hydraulic or pneumatic control system. The architecture includes a plurality of clustered control-component nodes with each node being alternatively configurable to independently control the operation of multiple single-acting controlled endpoint devices or a double-acting controlled endpoint device. Each node includes control-components including a solenoid, one or more valve spools independently controllable by the solenoid, and a low-level controller operable to control the solenoid. The solenoid, valve spools, and low-level controller are clustered together and physically co-located as a unit. The nodes are arranged in a control block with each node being uniquely identifiable for data communication via a data communication network. The data communication network may include a Controller Area Network (CAN). Multiple control blocks may be equipped with communication modules and linked for data communication between the control blocks.

The present disclosure discloses a hydraulic control system. The hydraulic control system may include a hydraulic module, a PLC control module, a hydraulic valve group control module, a manipulation module, and an action module. The manipulation module is connected with the PLC control module and is configured to input an operation instruction to the PLC control module; the PLC control module is respectively connected to the hydraulic module and the hydraulic valve group control module, and is configured to output a control signal corresponding to the operation instruction to the hydraulic valve group control module, and control the activation of the hydraulic module to provide hydraulic pressure to the hydraulic valve group control module; and the action module is connected with the hydraulic valve group control module, and is configured to perform an action corresponding to the control signal.

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.

An agricultural roundbaler includes a housing having a housing part, an ejection flap pivotably mounted on the housing part about a bearing axis, and drivable pressing apparatus arranged on the housing part and the ejection flap. The pressing apparatus define a bale pressing chamber on a peripheral side thereof. A control device operably pivots the ejection flap such that an ejection opening is formed between the housing part and the ejection flap. During an unloading process, the ejection flap is adjustably pivoted by the control device from an unloading position in which the fully pressed round bale is unloaded through the ejection opening to a retained position in which the unloaded round bale is retained by the ejection flap. The ejection flap is pivotable from the retained position to a relieved position in which the retained round bale is released by the ejection flap to eject from the pressing chamber.

Apparatus and methods for controlling a hydraulic cylinder with a control valve in a control system. The control system comprises a voltage level shifter that produces a shift reference voltage (SHRv) substantially equal to the fraction value of a valve power supply voltage (VPSv). A controller produces a control system output voltage (CNTo) with a positive value, a negative value, or a zero value in response to a control input voltage (CNTi) and the VPSv. A voltage converter receives the SHRv and CNTo, and provides a control signal input voltage (CSi) to the control valve. The CSi is greater than the fraction value of the VPSv when the CNTo is the positive value, less than the fraction value of the VPSv when the CNTo is the negative value, and substantially equal to the fraction value of the VPSv when the CNTo is the zero value.

A triplex pneumatic architecture system is disclosed having first, second, and third pneumatic subsystems where triplex redundancy may be accomplished by measuring only one particular node in each system, such as a measured current of the servo valve. Each of the first, second, and third pneumatic subsystems are configured to control a separate redundant pneumatic actuation assembly. Each subsystem may comprise a current sensor to measure a control current from a servo driver to a servo valve that controls the pneumatic actuation assembly to output a measured current value, and a dump valve coupled to a relay. Each processor is configured to generate a termination signal to actuate the first relay to open the first dump valve. The triplex pneumatic architecture system further includes a communication bus to communicatively couple each of the first, second, and third pneumatic subsystems. Each processor is configured to generate the termination signal and to communicate the termination signal to one or more of the relays when one measured current value deviates from the two other measured current values by a predetermined error value.

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.

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.

A controller for a valve assembly that is configured to meet requirements for use in hazardous areas. These configurations may regulate flow of instrument air to a pneumatic actuator to operate a valve. The controller may comprise enclosures, including a first enclosure and a second enclosure, each having a peripheral wall forming an interior space, and circuitry comprising a barrier circuit disposed in the interior space of one of the enclosures that power limits digital signals that exits that enclosure. In one example, the peripheral wall of enclosures are configured to allow instrument air into the interior space of the first enclosure but to prevent instrument air from the interior space of the second enclosure.