Abstract: The present disclosure relates to fault detection, isolation and reconfiguration schemes, architectures and methods for use in electrohydraulic actuation systems for construction equipment. In one embodiment, a supervisory controller adapted to interface with a main controller of the construction vehicle is provided. A plurality of control nodes that interface with the supervisory controller are also disclosed, each of which includes pressure and position sensors. The nodes also include a first actuator control node for controlling operation of a first hydraulic actuator, a second actuator control node for controlling operation of a second hydraulic actuator, and a pump control node. The control system has an architecture in which faults are detected and isolated at the supervisory controller level and, where possible, within each of the control nodes at a sensor level, a component level, and a subsystem level.

Abstract: A hydraulic system is adapted to recover potential and kinetic energy of a work attachment of a work machine. A valve arrangement may configure the hydraulic system in various modes. The hydraulic system may provide suspension and/or actuation for the work attachment. The energy of the work attachment may move a rod of a first cylinder. The rod may pressurize fluid within the first cylinder. The pressurized fluid may flow from the first cylinder through a valve and into an accumulator. The first cylinder may amplify pressure of the fluid. The pressurized fluid in the accumulator may actuate the first cylinder. The movement of the rod of the first cylinder may cause simultaneous actuation of a second cylinder. A controller may monitor pressures and positions of components of the hydraulic system and control the valve arrangement.

Abstract: A hydraulic system is adapted to recover potential and kinetic energy of a work attachment of a work machine. A valve arrangement may configure the hydraulic system in various modes. The hydraulic system may provide suspension and/or actuation for the work attachment. The energy of the work attachment may move a rod of a first cylinder. The rod may pressurize fluid within the first cylinder. The pressurized fluid may flow from the first cylinder through a valve and into an accumulator. The first cylinder may amplify pressure of the fluid. The pressurized fluid in the accumulator may actuate the first cylinder. The movement of the rod of the first cylinder may cause simultaneous actuation of a second cylinder. A controller may monitor pressures and positions of components of the hydraulic system and control the valve arrangement.

Abstract: A hydraulic circuit for lifting and lowering a load is disclosed. The hydraulic circuit may include a hydraulic pump, a fluid reservoir, a load-sense valve, and a hydraulic actuator having a first chamber and a second chamber. The hydraulic circuit may also include a first control valve assembly having first and second lowering positions, the valve being disposed between the hydraulic pump and the hydraulic actuator. A second control valve assembly may also be provided that is disposed between the first control valve assembly and the first chamber of the hydraulic actuator. In one embodiment, the second control valve assembly has a first position and a second position. In one embodiment, the load can be selectively lowered by the hydraulic circuit without use of the hydraulic pump when the first control valve assembly is in the first lowering position and the second control valve assembly is in the second position.

Abstract: The present disclosure relates to fault detection, isolation and reconfiguration schemes, architectures and methods for use in electrohydraulic actuation systems for construction equipment. In one embodiment, a supervisory controller adapted to interface with a main controller of the construction vehicle is provided. A plurality of control nodes that interface with the supervisory controller are also disclosed, each of which includes pressure and position sensors. The nodes also include a first actuator control node for controlling operation of a first hydraulic actuator, a second actuator control node for controlling operation of a second hydraulic actuator, and a pump control node. The control system has an architecture in which faults are detected and isolated at the supervisory controller level and, where possible, within each of the control nodes at a sensor level, a component level, and a subsystem level.

Abstract: The present disclosure relates to fault detection, isolation and reconfiguration schemes, architectures and methods for use in electrohydraulic actuation systems for construction equipment. In one embodiment, a supervisory controller adapted to interface with a main controller of the construction vehicle is provided. A plurality of control nodes that interface with the supervisory controller are also disclosed, each of which includes pressure and position sensors. The nodes also include a first actuator control node for controlling operation of a first hydraulic actuator, a second actuator control node for controlling operation of a second hydraulic actuator, and a pump control node. The control system has an architecture in which faults are detected and isolated at the supervisory controller level and, where possible, within each of the control nodes at a sensor level, a component level, and a subsystem level.

Abstract: The present disclosure relates to fault detection, isolation and reconfiguration schemes, architectures and methods for use in electrohydraulic actuation systems for construction equipment. In one embodiment, a supervisory controller adapted to interface with a main controller of the construction vehicle is provided. A plurality of control nodes that interface with the supervisory controller are also disclosed, each of which includes pressure and position sensors. The nodes also include a first actuator control node for controlling operation of a first hydraulic actuator, a second actuator control node for controlling operation of a second hydraulic actuator, and a pump control node. The control system has an architecture in which faults are detected and isolated at the supervisory controller level and, where possible, within each of the control nodes at a sensor level, a component level, and a subsystem level.

Abstract: The present disclosure relates to fault detection, isolation and reconfiguration schemes, architectures and methods for use in electrohydraulic actuation systems for construction equipment. In one embodiment, a supervisory controller adapted to interface with a main controller of the construction vehicle is provided. A plurality of control nodes that interface with the supervisory controller are also disclosed, each of which includes pressure and position sensors. The nodes also include a first actuator control node for controlling operation of a first hydraulic actuator, a second actuator control node for controlling operation of a second hydraulic actuator, and a pump control node. The control system has an architecture in which faults are detected and isolated at the supervisory controller level and, where possible, within each of the control nodes at a sensor level, a component level, and a subsystem level.

Abstract: A hydraulic system includes a pump (22) that draws fluid from a reservoir (24) and an actuator (26) having a first port and a second port. A metering valve arrangement (28) controls fluid flow through the actuator and includes a meter-in valve (30a, 30d) positioned between the pump and the first port and a meter-out valve (30b, 30c) positioned between the second port and the reservoir. A controller (34) controls operation of the metering valve arrangement. In a meter-in mode, the controller controls a fluid flow rate through the actuator by controlling an orifice size of the meter-in valve. In a meter-out mode, the controller controls a fluid flow rate through the actuator by controlling an orifice size of the meter-out valve. The controller determines the fluid flow rate through the actuator based on data derived from the meter-out valve in both the meter-in mode and the meter-out mode.

Abstract: A steering system includes a fluid pump and an electro-hydraulic steering circuit in selective fluid communication with the fluid pump. The electro-hydraulic steering circuit defines a first flow path having a first proportional valve and a first load-sense passage in selective communication with the first proportional valve. The first proportional valve includes a closed position. A hydrostatic steering circuit is in selective fluid communication with the fluid pump and defines a second flow path having a second proportional valve and a second load-sense passage in selective fluid communication with the second proportional valve. The second flow path is in a parallel flow configuration with the first flow path. An isolation valve is disposed in the first flow path in series with the first proportional valve. The isolation valve includes a closed position and is piloted to the closed position by fluid communicated through the second load-sense passage.

Abstract: A hydraulic circuit for lifting and lowering a load is disclosed. The hydraulic circuit may include a hydraulic pump, a fluid reservoir, a load-sense valve, and a hydraulic actuator having a first chamber and a second chamber. The hydraulic circuit may also include a first control valve assembly having first and second lowering positions, the valve being disposed between the hydraulic pump and the hydraulic actuator. A second control valve assembly may also be provided that is disposed between the first control valve assembly and the first chamber of the hydraulic actuator. In one embodiment, the second control valve assembly has a first position and a second position. In one embodiment, the load can be selectively lowered by the hydraulic circuit without use of the hydraulic pump when the first control valve assembly is in the first lowering position and the second control valve assembly is in the second position.

Abstract: A valve assembly includes a valve housing defining a service passage, a first bore in fluid communication with the service passage, a first passage, a second bore in communication with the service passage and a second passage. The first bore has an inlet portion, a first service portion in communication with the service passage, and a first load holding portion. The first passage is in communication with the first load holding portion and the service passage. The second bore has a return portion, a second service portion in fluid communication with the first service passage, and a second load holding portion. The second passage is in selective communication with the second load holding portion of the second bore and the return passage. A valve is disposed in the second passage. The valve allows fluid to flow only in a direction from the second load holding portion to the return passage.

Abstract: A steering system includes a fluid actuator, a first steering circuit in selective fluid communication with the fluid actuator, and a second steering circuit in selective fluid communication with the fluid actuator and disposed in parallel to the first steering circuit. The second steering circuit includes a load-reaction feature and an isolation valve with the isolation valve being adapted to enable and disable the load-reaction feature.

Abstract: The present disclosure relates to fault detection, isolation and reconfiguration schemes, architectures and methods for use in electrohydraulic actuation systems for construction equipment. In one embodiment, a supervisory controller adapted to interface with a main controller of the construction vehicle is provided. A plurality of control nodes that interface with the supervisory controller are also disclosed, each of which includes pressure and position sensors. The nodes also include a first actuator control node for controlling operation of a first hydraulic actuator, a second actuator control node for controlling operation of a second hydraulic actuator, and a pump control node. The control system has an architecture in which faults are detected and isolated at the supervisory controller level and, where possible, within each of the control nodes at a sensor level, a component level, and a subsystem level.

Abstract: A hydraulic system is adapted to recover potential and kinetic energy of a work attachment of a work machine. A valve arrangement may configure the hydraulic system in various modes. The hydraulic system may provide suspension and/or actuation for the work attachment. The energy of the work attachment may move a rod of a first cylinder. The rod may pressurize fluid within the first cylinder. The pressurized fluid may flow from the first cylinder through a valve and into an accumulator. The first cylinder may amplify pressure of the fluid. The pressurized fluid in the accumulator may actuate the first cylinder. The movement of the rod of the first cylinder may cause simultaneous actuation of a second cylinder. A controller may monitor pressures and positions of components of the hydraulic system and control the valve arrangement.

Abstract: A steering system includes a fluid pump and an electro-hydraulic steering circuit in selective fluid communication with the fluid pump. The electro-hydraulic steering circuit defines a first flow path having a first proportional valve and a first load-sense passage in selective communication with the first proportional valve. The first proportional valve includes a closed position. A hydrostatic steering circuit is in selective fluid communication with the fluid pump and defines a second flow path having a second proportional valve and a second load-sense passage in selective fluid communication with the second proportional valve. The second flow path is in a parallel flow configuration with the first flow path. An isolation valve is disposed in the first flow path in series with the first proportional valve. The isolation valve includes a closed position and is piloted to the closed position by fluid communicated through the second load-sense passage.

Abstract: A steering system includes a fluid actuator, a first steering circuit in selective fluid communication with the fluid actuator, and a second steering circuit in selective fluid communication with the fluid actuator and disposed in parallel to the first steering circuit. The second steering circuit includes a load-reaction feature and an isolation valve with the isolation valve being adapted to enable and disable the load-reaction feature.

Abstract: A steering system includes a fluid pump and an electro-hydraulic steering circuit in selective fluid communication with the fluid pump. The electro-hydraulic steering circuit defines a first flow path having a first proportional valve and a first load-sense passage in selective communication with the first proportional valve. The first proportional valve includes a closed position. A hydrostatic steering circuit is in selective fluid communication with the fluid pump and defines a second flow path having a second proportional valve and a second load-sense passage in selective fluid communication with the second proportional valve. The second flow path is in a parallel flow configuration with the first flow path. An isolation valve is disposed in the first flow path in series with the first proportional valve. The isolation valve includes a closed position and is piloted to the closed position by fluid communicated through the second load-sense passage.

Abstract: A valve assembly includes a valve housing defining a service passage, a first bore in fluid communication with the service passage, a first passage, a second bore in communication with the service passage and a second passage. The first bore has an inlet portion, a first service portion in communication with the service passage, and a first load holding portion. The first passage is in communication with the first load holding portion and the service passage. The second bore has a return portion, a second service portion in fluid communication with the first service passage, and a second load holding portion. The second passage is in selective communication with the second load holding portion of the second bore and the return passage. A valve is disposed in the second passage. The valve allows fluid to flow only in a direction from the second load holding portion to the return passage.

Abstract: A steering system includes a fluid actuator, a first steering circuit in selective fluid communication with the fluid actuator, and a second steering circuit in selective fluid communication with the fluid actuator and disposed in parallel to the first steering circuit. The second steering circuit includes a load-reaction feature and an isolation valve with the isolation valve being adapted to enable and disable the load-reaction feature.