Abstract: Disclosed is an exemplary valve having a first valve member that may include at least one orifice, and which is moveable between a first position and a second position, and a second valve member that includes at least one orifice, and which is moveable relative to the first valve member between a first position, in which the at least one orifice of the second valve member is fluidly disconnected from the at least one orifice of the first valve member, and a second position, in which the at least one orifice of the second valve member is fluidly connected to the at least one orifice of the first valve member. The exemplary valve may also include first and second actuators for moving the first and second valve members between their respective first and second positions.

Abstract: A high intensity discharge (HID) ballast circuit comprises a trigger circuit, a power half-bridge self-excited oscillation circuit, which is arranged to enable self-excited oscillation by energizing an angle capacitor Cgs with a Miller capacitor Cdg of a power MOSFET when an original single pulse output by the trigger circuit is excited, and then output self-excited oscillation signals; and a filter loop which is arranged to match impedance for the self-excited oscillation signals, thereby converting a low-impedance voltage source to a high-impedance constant current source. The inherent phase relationship of the power MOSFET is utilized, and oscillation signals are generated by a power half-bridge self-excited oscillation circuit, and then impedance matching for the oscillation signals is performed by the filter loop, and finally an HID lamp is triggered. As a result, damages to human eyes caused by stroboscopic effect can be avoided and electro magnetic compatibility test can be passed.

Abstract: A flow control valve includes a housing that includes a fluid inlet, a fluid outlet, a first work port and a second work port. The housing defines a spool bore and a pilot spool bore. A main stage spool is disposed in the spool bore. A pilot stage spool is disposed in the pilot spool bore. The pilot stage spool is in selective fluid communication with the main stage spool. A microprocessor includes a controller having a restricted structured controller and a compensation controller. Outputs of the restricted structured controller and the compensation controller are summed to form an electrical signal that is communicated to the pilot stage spool.

Abstract: A flow control valve includes a housing that includes a fluid inlet, a fluid outlet, a first work port and a second work port. The housing defines a spool bore and a pilot spool bore. A main stage spool is disposed in the spool bore. A pilot stage spool is disposed in the pilot spool bore. The pilot stage spool is in selective fluid communication with the main stage spool. A microprocessor includes a controller having a restricted structured controller and a compensation controller. Outputs of the restricted structured controller and the compensation controller are summed to form an electrical signal that is communicated to the pilot stage spool.

Abstract: Methods for controlling the net-displacement of a rotary fluid pressure device are disclosed. One of the net-displacement control methods (47) includes obtaining a desired input parameter (23) and a relative position (21) of a first member (43) and a second member (35) of a fluid displacement mechanism. A determination of a first and second output value is then made for each of a plurality of volume chambers (45) when the volume chambers (45) are supplied with fluid at fluid inlet and fluid outlet conditions, respectively. A total output value is then computed for each of a plurality of control valve configurations (63) and compared to the desired input parameter (23). The control valve configuration (63) with the total output value most similar to the desired input parameter (23) is then selected. A plurality of control valves (15) are then actuated in accordance with the selected control valve configuration (63).

Abstract: A fluid circuit includes a tank for holding fluid, a hydraulic device having a predetermined load configuration, and a pump for delivering the fluid under pressure to the hydraulic device. Sensors measure at least one of a supply pressure, a tank pressure, and a position of a portion of the hydraulic device. A controller estimates or reconstructs an output value of any one sensor using the predetermined load configuration in the event of a predetermined failure of that sensor, ensuring continued operation of the hydraulic device. A method for estimating the output value includes sensing output values using the sensors, processing the output values using the controller to determine the presence of a failed sensor, and calculating an estimated output value of the failed sensor using the predetermined load configuration. Operation of the hydraulic device is maintained using the estimated output value until the failed sensor can be repaired.

Abstract: A method for controlling a boom assembly includes providing a boom assembly having an end effortor. The boom assembly includes an actuator in fluid communication with a flow control valve. A desired coordinate of the end effector of the boom assembly is converted from Cartesian space to actuator space. A deflection error of the end effector based on a measured displacement of the actuator is calculated. A resultant desired coordinate of the end effector is calculated based on the desired coordinate and the deflection error. A control signal for the flow control valve is generated based on the resultant desired coordinate and the measured displacement of the actuator. The control signal is shaped to reduce vibration of the boom assembly. The shaped control signal is transmitted to the flow control valve.

Abstract: A flow control valve includes a housing that includes a fluid inlet, a fluid outlet, a first work port and a second work port. The housing defines a spool bore and a pilot spool bore. A main stage spool is disposed in the spool bore. A pilot stage spool is disposed in the pilot spool bore. The pilot stage spool is in selective fluid communication with the main stage spool. A microprocessor includes a controller having a restricted structured controller and a compensation controller. Outputs of the restricted structured controller and the compensation controller are summed to form an electrical signal that is communicated to the pilot stage spool.

Abstract: A method for controlling a rotary fluid device includes providing a rotary fluid device having a fluid displacement assembly and a plurality of control valves. The fluid displacement assembly includes a first member and a second member. The first and second members have relative movement and define a plurality of volume chambers. The plurality of control valves is in fluid communication with the plurality of volume chambers. A desired displacement is received. A relative position of the first and second members is determined. An optimal displacement family is selected from a plurality of displacement families that is based on peak displacements of a plurality of displacement curves. A phase shift angle for the optimal displacement family is selected so that an actual displacement of the fluid displacement assembly approaches the desired displacement. The control valves of the rotary fluid device are actuated in accordance with the phase shift angle.

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: Methods for controlling the net-displacement of a rotary fluid pressure device are disclosed. One of the net-displacement control methods (47) includes obtaining a desired input parameter (23) and a relative position (21) of a first member (43) and a second member (35) of a fluid displacement mechanism. A determination of a first and second output value is then made for each of a plurality of volume chambers (45) when the volume chambers (45) are supplied with fluid at fluid inlet and fluid outlet conditions, respectively. A total output value is then computed for each of a plurality of control valve configurations (63) and compared to the desired input parameter (23). The control valve configuration (63) with the total output value most similar to the desired input parameter (23) is then selected. A plurality of control valves (15) are then actuated in accordance with the selected control valve configuration (63).

Abstract: A flow control valve includes a housing that includes a fluid inlet, a fluid outlet, a first work port and a second work port. The housing defines a spool bore and a pilot spool bore. A main stage spool is disposed in the spool bore. A pilot stage spool is disposed in the pilot spool bore. The pilot stage spool is in selective fluid communication with the main stage spool. A microprocessor includes a controller having a restricted structured controller and a compensation controller. Outputs of the restricted structured controller and the compensation controller are summed to form an electrical signal that is communicated to the pilot stage spool.

Abstract: A hydraulic circuit architecture for use in a drive circuit having a hydraulic pump for driving a load is disclosed. The hydraulic circuit architecture includes a flow control valve for controlling a hydraulic fluid flow rate supplied from the hydraulic pump to the load. The hydraulic circuit architecture also includes a hydraulic fluid accumulator arranged in parallel with respect to the flow control valve. Hydraulic circuit architectures having multiple accumulators arranged in parallel with respect to the flow control valve are also disclosed.

Abstract: A hydraulic drive system for driving a load includes a drive shaft; first and second hydraulic pumps driven by the drive shaft, and a control system that operates the hydraulic drive system in a plurality of modes including: a) a first mode where the second hydraulic pump pumps hydraulic fluid from a supply line to an accumulator; b) a second mode where the second hydraulic pump pumps hydraulic fluid from the accumulator to the supply line; c) a third mode where the second hydraulic pump pumps hydraulic fluid from the supply line to a reservoir; and d) a fourth mode where the second hydraulic pump pumps hydraulic fluid from the reservoir to the supply line. At least the second hydraulic pump is a variable displacement bidirectional pump.

Abstract: Disclosed is an exemplary valve having a first valve member that may include at least one orifice, and which is moveable between a first position and a second position, and a second valve member that includes at least one orifice, and which is moveable relative to the first valve member between a first position, in which the at least one orifice of the second valve member is fluidly disconnected from the at least one orifice of the first valve member, and a second position, in which the at least one orifice of the second valve member is fluidly connected to the at least one orifice of the first valve member. The exemplary valve may also include first and second actuators for moving the first and second valve members between their respective first and second positions.

Abstract: A damping control system includes a first sensor configured to detect movement of a vessel and generate a first signal representing the vessel movement and a second sensor configured to detect movement of a cable and generate a second signal representing the cable movement. An actuator is configured to dampen a force applied to a payload during a force event. The force event is at least partially caused by the movement of the vessel and the cable. A controller is configured to identify the force event based at least in part on the first and second signals and control the actuator during the force event to substantially dampen the force applied to the payload.

Abstract: A method for controlling stability of a vehicle includes the steps of determining a predictive lateral load transfer ratio of the vehicle by evaluating vehicle performance factors over a period of time, and controlling operation of the vehicle based on the predictive lateral load transfer ratio.

Abstract: A fluid circuit includes a tank for holding fluid, a hydraulic device having a predetermined load configuration, and a pump for delivering the fluid under pressure to the hydraulic device. Sensors measure at least one of a supply pressure, a tank pressure, and a position of a portion of the hydraulic device. A controller estimates or reconstructs an output value of any one sensor using the predetermined load configuration in the event of a predetermined failure of that sensor, ensuring continued operation of the hydraulic device. A method for estimating the output value includes sensing output values using the sensors, processing the output values using the controller to determine the presence of a failed sensor, and calculating an estimated output value of the failed sensor using the predetermined load configuration. Operation of the hydraulic device is maintained using the estimated output value until the failed sensor can be repaired.

Abstract: A method for controlling a boom assembly includes providing a boom assembly having an end effortor. The boom assembly includes an actuator in fluid communication with a flow control valve. A desired coordinate of the end effector of the boom assembly is converted from Cartesian space to actuator space. A deflection error of the end effector based on a measured displacement of the actuator is calculated. A resultant desired coordinate of the end effector is calculated based on the desired coordinate and the deflection error. A control signal for the flow control valve is generated based on the resultant desired coordinate and the measured displacement of the actuator. The control signal is shaped to reduce vibration of the boom assembly. The shaped control signal is transmitted to the flow control valve.

Abstract: A method for controlling a rotary fluid device includes providing a rotary fluid device having a fluid displacement assembly and a plurality of control valves. The fluid displacement assembly includes a first member and a second member. The first and second members have relative movement and define a plurality of volume chambers. The plurality of control valves is in fluid communication with the plurality of volume chambers. A desired displacement is received. A relative position of the first and second members is determined. An optimal displacement family is selected from a plurality of displacement families that is based on peak displacements of a plurality of displacement curves. A phase shift angle for the optimal displacement family is selected so that an actual displacement of the fluid displacement assembly approaches the desired displacement. The control valves of the rotary fluid device are actuated in accordance with the phase shift angle.