Abstract: A control system (201) for a frame-steered vehicle that includes a first steering cylinder (104) and a second steering cylinder (105). The steering cylinders are arranged for frame-steering of the vehicle. The system includes a first drive unit (202) and a second drive unit (204), each of which has an electrical machine (206,208) and a hydraulic machine (210,212). Each respective electrical machine is drivingly connected to its associated hydraulic machine, wherein with a first (210) of the two hydraulic machines is arranged for flow-communication with a piston side (214) of the first steering cylinder (104) and a piston rod side (216) of the second steering cylinder (105). A second (212) of the two hydraulic machines is arranged for flow-communication with a piston side (218) of the second steering cylinder and a piston rod side (220) of the first steering cylinder.

Abstract: A method is provided for, when necessary, automatically limiting a pressure in a hydraulic system during operation. A system is arranged to deliver pressurized hydraulic fluid to at least one fluid actuated device arranged to perform a work function, where the procedure includes sensing a pressure in at least one position of the system, comparing the detected pressure value, or an associated value, with a first predefined pressure limit, and opening a communication of fluid between the fluid actuated device and a reservoir through a first conduit if the sensed pressure value, or an associated value, exceeds the predefined limit.

Abstract: A method for controlling a working machine including a hydraulic system for controlling a plurality of work functions, including lift and tilt of an implement, includes the steps of determining a maximum pressure of a hydraulic fluid for performing a certain task with the implement individually for at least one of the work functions, and delivering the hydraulic fluid, pressurized at most to the determined maximum pressure, to the work function.

Abstract: A system for a working machine is adapted for springing the movement of a load during transport and includes at least one hydraulic cylinder for operating the load, an accumulator, and a valve adapted to control a flow communication between the hydraulic cylinder and the accumulator. The system includes a first control valve arranged on a conduit connecting to the piston side of the hydraulic cylinder, a second control valve arranged on a conduit connecting to the piston rod side of the hydraulic cylinder, a first pressure sensor for detecting a load pressure of the hydraulic cylinder, a second pressure sensor for detecting a charge pressure of the accumulator, and a control unit adapted to receive signals with information about the pressures detected by the pressure sensors and to generate control signals corresponding to the detected pressures for controlling the springing function.

Abstract: A load sensing system includes a first assembly of actuators for controlling a first hydraulic function, a pump adapted to supply the actuators with pressurized hydraulic fluid, an electrically controlled valve adapted to control the output pressure of the pump via a hydraulic signal, a first pressure sensor for detecting a load pressure of the first actuator assembly, and a control unit adapted to receive a signal with information about the load pressure detected by the first pressure sensor and to generate a control signal, corresponding to the detected load pressure, to the electrically controlled valve.

Abstract: An arrangement for controlling a work vehicle includes a power source, and a hydraulic circuit including a pump driven by the power source, at least one hydraulic actuator arranged in fluid connection with the pump via a first conduit, a variable displacement hydraulic motor unit arranged in fluid connection with the actuator and downstream the actuator via a second conduit. The variable displacement hydraulic motor unit is arranged for controlling movement of the actuator.

Abstract: A method is provided for controlling movement of a first vehicle component relative to a second vehicle component, including the steps of determining a deceleration rate of the first vehicle component in order to achieve a predetermined final speed at a final position, determining a starting position for initiating the deceleration on the predetermined final speed, the final position and the determined deceleration rate and controlling deceleration of the component from the starting position to the final position according to the determined acceleration rate.

Abstract: A control system for a work machine is provided, which system includes an electric machine, a hydraulic machine and at least one hydraulic cylinder. The electric machine is connected in a driving manner to the hydraulic machine. The hydraulic machine is connected to a piston side of the hydraulic cylinder via a first line and a piston-rod side of the hydraulic cylinder via a second line. The hydraulic machine is adapted to be driven by the electric machine and supply the hydraulic cylinder with pressurized hydraulic fluid from a tank in a first operating state and to be driven by a hydraulic fluid flow from the hydraulic cylinder and drive the electric machine in a second operating state.

Abstract: System for controlling at least one hydraulic cylinder (2, 3) having a first control valve unit (4) connected to the hydraulic cylinder for regulation thereof. A first operable control means (5) is included and which is adapted for controlling the first control valve unit. A second control valve unit (6) is also included that is connected to the hydraulic cylinder for regulation thereof, and a second operable control means (7) is further provided and which is adapted for controlling the second control valve unit. The system also includes means (23) for prioritizing the first control means. The prioritizing means (23) is controlled via hydraulics in such a way that the effect of the second control means (6) on the regulation of the hydraulic cylinder (2, 3) is at least substantially reduced as soon as the first control means (5) is operated.

Abstract: A method and arrangement for controlling a function of a work implement utilizing a device including a source of pressurized fluid (1), a circuit of pressurized fluid (2) for driving the work implement, an electronically controlled hydraulic valve (5) being arranged in the circuit of pressurized fluid (2) for controlling the function of the work implement, a control unit (4) for controlling the hydraulic valve (5) based upon a signal from a control member (3) for transmitting a control command to the control unit (4), wherein the control unit (4) is arranged for controlling the hydraulic valve (5) in accordance with a smooth mode function or an abrupt mode function. The opening time for opening the hydraulic valve (5) to a predetermined opening degree is changed when switching from one operating mode function to the other operating mode function.

Abstract: Method and arrangement for controlling a work vehicle that includes a hydraulic system (22) having at least one pump (18,180) and at least one actuator (4,5,8,9,10) operatively driven by hydraulic fluid delivered from the pump and at least a first pump (18) is a variable displacement pump. The system (22) is of the load-sensing type in that pump displacement is controlled by a pilot pressure representing a load exerted on the system. The arrangement includes means (63) for reducing the pilot pressure delivered to the first pump (18) so that the first pump displacement is regulated down when there is a need for limiting hydraulic power consumption.

Abstract: A hydraulic system includes a first pump that delivers hydraulic fluid to a first load outlet point and to a second load outlet point, a second pump that delivers hydraulic fluid to the second load outlet point, but not to the first load outlet point, a pressure detector for detecting the load pressure at the first load outlet point and a pressure detector for detecting the load pressure at the second load outlet point. The system includes a controller for controlling the first pump on the basis of the detected load pressure at the first load outlet point and the detected load pressure at the second load outlet point, and a controller for controlling the second pump on the basis of the detected load pressure at the second load outlet point but not on the basis of the detected load pressure at the first load outlet point.

Abstract: A method is provided for controlling a hydraulic cylinder, including detecting at least one operating parameter, and variably controlling a communication path between the piston-rod side and piston side of the hydraulic cylinder on the basis of the detected operating parameter.

Abstract: A method for springing a movement of an implement of a work machine during a movement of the work machine is provided, in which at least one hydraulic cylinder is connected to the implement for controlling its movements, comprising the steps of connecting a hydraulic machine to the hydraulic cylinder, and of controlling the hydraulic machine in response to a disturbance acting upon the implement during the movement of the work machine.

Abstract: A method is provided for controlling a hydraulic cylinder in a work machine, which hydraulic cylinder is arranged to move an implement in relation to a part of a vehicle, with the hydraulic cylinder being controlled by a hydraulic machine. The method includes the steps of detecting initiation of a movement of the implement that is such that the piston of the hydraulic cylinder is moved in a first direction, of driving the hydraulic machine in a first rotational direction, prior to the movement of the implement taking place, so that a line from the hydraulic machine is pressurized, which line is arranged to connect the hydraulic machine to the side of the cylinder toward which the piston will be moved during the movement of the implement.

Abstract: A method is provided for controlling a hydraulic machine in a control system when utilizing the hydraulic machine as a pump, in which an electric machine is connected in a driving manner to the hydraulic machine. The method includes detecting at least one operating parameter, determining, based on the detected operating parameter, whether a pressure supplied by the hydraulic machine is to be limited, and controlling the electric machine correspondingly.

Abstract: A method is provided for controlling a hydraulic cylinder in a work machine, which hydraulic cylinder is arranged to move an implement that is subjected to a load, with the hydraulic cylinder being controlled by a hydraulic machine. The method includes detecting that a lifting movement of the implement is to be initiated, and attaining a basic speed of the hydraulic machine before lifting takes place.

Abstract: A system is provided for controlling the tilting of a load-carrying implement of a movable work machine that includes a frame and the implement, pivotally connected to the frame, and a tilting arrangement for tilting the implement in relation to the frame. The system includes a control for controlling the tilting of the implement based upon a sensor-registered movement of the movable work machine, and for controlling the tilting of the implement such that the implement counteracts the inertia of a load carried by the implement.

Abstract: A method for damping relative movements occurring between a first and a second part of a work vehicle during advance of the vehicle, which parts are interconnected by means of at least one hydraulic actuator, includes detecting at least one operation parameter of the vehicle, determining whether a damping condition is present based on the detected operation parameter and if the determined damping condition is present, controlling a displacement of a variable displacement hydraulic motor arranged downstream of the actuator in such a way that energy from a hydraulic fluid transmitted from the actuator is converted to a rotational energy in the motor, and transmitting the recovered energy from the motor to a power source.

Abstract: A control system (201) for a frame-steered vehicle that includes a first steering cylinder (104) and a second steering cylinder (105). The steering cylinders are arranged for frame-steering of the vehicle. The system includes a first drive unit (202) and a second drive unit (204), each of which has an electrical machine (206,208) and a hydraulic machine (210,212). Each respective electrical machine is drivingly connected to its associated hydraulic machine, wherein with a first (210) of the two hydraulic machines is arranged for flow-communication with a piston side (214) of the first steering cylinder (104) and a piston rod side (216) of the second steering cylinder (105). A second (212) of the two hydraulic machines is arranged for flow-communication with a piston side (218) of the second steering cylinder and a piston rod side (220) of the first steering cylinder.