Methods and apparatus for quantifying pneumatic volume usage via valve controllers are disclosed. An example apparatus includes a valve controller operatively couplable to a pneumatic actuator, the pneumatic actuator being operatively coupled to a control valve. In response to an input signal indicating that a flow control member of the control valve is to be moved in a specified direction, the valve controller commands a current-to-pressure (I/P) converter of the valve controller to pulse a relay valve of the valve controller between a closed position and an open position. The pulsing of the relay valve causes the pneumatic actuator to move the flow control member in the specified direction. The valve controller calculates a pneumatic volume usage associated with the moving of the flow control member in the specified direction. The pneumatic volume usage is based on the pulsing of the relay valve.

A control method for executing a floating function of a boom in a work vehicle includes determining that a predetermined floating function activation command has been inputted by the operator by means of a command input means. When the floating function activation command has been inputted by the operator, acquiring, a signal or data indicative of the current position of the boom along a travel path of the boom over time, the travel path including a first section between a boom full extension position and a deceleration position, a second section between the deceleration position and a grounding position, and a third section between the grounding position and a full retract position, and moving the boom from the current position, determined based on the signal or data indicative of the position of the boom, to the full retract position.

A method for controlling a cylinder includes providing a cylinder having a piston, a servo valve and a measuring device having at least one first position sensor and one second position sensor, measurements are taken of the position of the piston in the cylinder body simultaneously with the first position sensor and the second position sensor, at least one first displacement speed of the piston is determined on the basis of the piston position measurements obtained with the first position sensor, at least one second displacement speed of the piston is determined on the basis of the piston position measurements obtained with the second position sensor, and each of the first and second determined displacement speeds of the piston are compared with a modelled or predetermined displacement speed of the piston, in such a way as to identify the most reliable position sensor.

In one aspect, an actuator for actuating a device comprises driving means adapted to be operatively connected to the device, and operable to receive a reaction element for engaging the device. The driving means further comprises an output adapted to be operatively engaged with the device for actuation of the device whilst the reaction element is engaging the device.

There is provided a construction machine that is capable of measuring a minute leakage flow rate of a one-sided tilting variable displacement hydraulic pump. The construction machine includes a pressure sensor that detects a pressure of a hydraulic pump, a bleed-off adjusting device that is enabled to adjust a bleed-off flow rate of the hydraulic pump, and an input device that gives an instruction for measurement of a leakage flow rate of the hydraulic pump. The controller is configured to measure, when the controller determines that the operation device is in a non-operated state and when a measuring command is inputted from the input device, a pressure of the hydraulic pump while changing a control command value for the bleed-off adjusting device in a state in which a flow rate of the hydraulic pump is maintained, and calculate the leakage flow rate of the hydraulic pump on the basis of the control command value for the bleed-off adjusting device at the time that the pressure of the hydraulic pump is stabilized at a predetermined pressure.

A work vehicle includes: a hydraulic pump driven by an engine; a hydraulic actuator that is driven by hydraulic oil supplied from the hydraulic pump; a switching valve configured to switch from one to the other of a first state in which the hydraulic oil supplied from the hydraulic pump is supplied to a first channel and a second state in which the hydraulic oil supplied from the hydraulic pump is supplied to a second channel; a restriction operation device configured to generate an operation signal that restricts the drive of the hydraulic actuator; and a controller that controls the switching valve. The controller includes: an operation signal acquisition unit configured to acquire the operation signal; and an instruction output unit configured to output, to the switching valve, a control instruction that restricts the drive of the hydraulic actuator with the engine driving, in response to the operation signal.

A refuse collection vehicle has various hydraulic actuators including at least one cylinder with an internal seal. A sensor is responsive to movement of the piston and sends a signal to a controller to indicate piston movement information during an associated vehicle body component movement. The controller is configured to determine a motion characteristic of the piston during a predetermined body component movement, compare the determined motion characteristic to a stored reference motion characteristic, and in response to determining that a difference between the determined motion characteristic and the reference motion characteristic is greater than a predetermined value, trigger an indication that the refuse collection vehicle is in need of service.

A hydraulic system for an automatic transmission of a motor vehicle, with which hydraulic cylinders of at least one clutch and of gear selectors can be actuated, which hydraulic system has a pressure accumulator for providing an accumulator pressure in the hydraulic system, wherein a clutch valve that can be actuated by the control unit is arranged in a clutch path leading from the pressure accumulator to the clutch hydraulic cylinder.

An integrated diagnostics system utilizes online and offline diagnostics techniques to evaluate control valves found in process plant environments. The integrated diagnostics system improves on existing diagnostic systems, which typically rely exclusively on online diagnostics or offline diagnostics.

The method for monitoring the condition of the hydraulic system for predicting the risk of failure is designed for hydraulic systems, whose components include at least one pump (1) for transporting fluid through the distribution system of the hydraulic system. The hydraulic system simultaneously detects at least one current magnitude of pressure and the current value of speed of the pump (1), whereupon the current speed value is compared with the trend speed value obtained from the statistically processed archived data of speed from the previous operation of the pump (1) and/or with the reference speed value of the pump (1), whereupon the comparison result provides the condition and risk of failure of the hydraulic system.