Provided is a hydraulic excavator including a controller that can control a work device by utilizing an excavation work control for causing a claw tip of a bucket to move along a predetermined target surface and a leveling work control for causing the bucket to move along the target surface while maintaining the posture of the bucket with respect to the target surface, in which: the controller, based on posture data and size data on a work device and position data on the target surface, calculates an arm tip difference Dva that is the distance from the tip of an arm to the target surface; and the controller executes the leveling work control in a case of the calculated arm tip difference being equal to or less than a predetermined threshold dv1, there being no input of a bucket operation to an operation lever, and there being an input of an arm operation to the operation lever, and otherwise executes the excavation work control.

Power machines and control systems used thereon include a lift cylinder, a tilt cylinder, and a slave cylinder mechanically connected to assist the lift cylinder with raising a boom. With a lift control valve controlled to cause extension of the lift cylinder to raise the boom, pressure from a hydraulic source is provided to the slave cylinder to aid in raising the boom. Resulting increased pressure on a side of the slave cylinder opens load holding valves, allowing hydraulic pressure from the tilt cylinder to be communicated to the slave cylinder such that tilt cylinder pressure due to a heavy load on an implement aids in raising the boom.

To provide a construction machine that can improve the energy efficiency in a leveling operation in which an arm crowding operation and a boom raising operation are performed simultaneously. A controller (30) controls a first regulator (60a) according to the maximum value among target displacement volume (Qa1) of a first hydraulic pump (1) that is based on a boom raising operation amount (Pi1), and target displacement volume (Qa2) of the first hydraulic pump (1) that is based on an arm crowding operation amount (Pi2) of an arm operation device (18) if the boom raising operation amount (Pi1) of a boom operation device (17) is smaller than a predetermined operation amount, or if a delivery pressure (P2) of a second hydraulic pump (2) is equal to or higher than a predetermined pressure, and controls the first regulator (60a) according only to the target displacement volume (Qa1) of the first hydraulic pump (1) that is based on the boom raising operation amount (Pi1) if the boom raising operation amount (Pi1) is equal to or larger than the predetermined operation amount, and the delivery pressure (P2) of the second hydraulic pump (2) is lower than the predetermined pressure.

Provided is an automatic leveling system restraining leveling-objects from collapsing. The automatic leveling system includes a work machine that performs leveling motion, an imaging device, and a controller. The imaging device acquires three-dimensional information about the shape and position of at least one of the leveling-objects and a peripheral object. The work machine is provided with a work attachment including a tip attachment. The controller sets a leveling area based on the acquired three-dimensional information and makes the work machine perform the leveling motion by the tip attachment within the leveling area.

The invention relates to a method (100) of operating an actuator arrangement including at least two types of actuators (6, 7, 11, 12, 30, 34) effectuating different types of movement of a connected device (10, 32) to be actuated, where a change of attitude of the connected device (10, 32) has an influence on the position of at least a defined part (13, 14) of the connected device (10, 32). Different types of actuators (6, 7, 11, 12, 30, 34) are actuated in an automated way to at least partly compensate for the change of position of the defined part (13, 14) of the connected device (10, 32) when changing the attitude of the connected device (10, 32), at least for a certain range of movements.

Mobile device includes a frame with displacement means, a working arm connected to the frame including at least a first and a second articulation which are hinged to each other. The working arm is hinged to the frame, and at least a first, second and third control devices are adapted for moving the first and second articulation of the working arm and a tool, respectively, at a free end of the second articulation. A control system is adapted for controlling the first, second and third control means. The control system is adapted to drive the first, second and third control means such that the free end of the second articulation follows a predetermined upward movement along an upwardly directed path and the tool remains in a lifting position, the first, second and third control means are simultaneously controlled.

To provide a construction machine that can improve the energy efficiency in a leveling operation in which an arm crowding operation and a boom raising operation are performed simultaneously. A controller (30) controls a first regulator (60a) according to the maximum value among target displacement volume (Qa1) of a first hydraulic pump (1) that is based on a boom raising operation amount (Pi1), and target displacement volume (Qa2) of the first hydraulic pump (1) that is based on an arm crowding operation amount (Pi2) of an arm operation device (18) if the boom raising operation amount (Pi1) of a boom operation device (17) is smaller than a predetermined operation amount, or if a delivery pressure (P2) of a second hydraulic pump (2) is equal to or higher than a predetermined pressure, and controls the first regulator (60a) according only to the target displacement volume (Qa1) of the first hydraulic pump (1) that is based on the boom raising operation amount (Pi1) if the boom raising operation amount (Pi1) is equal to or larger than the predetermined operation amount, and the delivery pressure (P2) of the second hydraulic pump (2) is lower than the predetermined pressure.

The invention relates to a method (100) of operating an actuator arrangement including at least two types of actuators (6, 7, 11, 12, 30, 34) effectuating different types of movement of a connected device (10, 32) to be actuated, where a change of attitude of the connected device (10, 32) has an influence on the position of at least a defined part (13, 14) of the connected device (10, 32). Different types of actuators (6, 7, 11, 12, 30, 34) are actuated in an automated way to at least partly compensate for the change of position of the defined part (13, 14) of the connected device (10, 32) when changing the attitude of the connected device (10, 32), at least for a certain range of movements.

The invention relates to a civil engineering device and a civil engineering method for using a civil engineering device. The device has a support device, a ground preparation tool, which prepares the ground at a preparation location, and at least one GPS unit, which is arranged on the support device and is designed to determine the position of the preparation location, wherein the GPS unit is arranged at a distance from the ground preparation location. The civil engineering device is characterised in that a measuring device is provided in addition to the GPS unit, the measuring device being designed to determine the distance between the GPS unit and the preparation tool.

A carrier comprising at least a first hydraulic cylinder and a second hydraulic cylinder both having each a piston and a piston position sensor, wherein the carrier is arranged to carry a tool through the use of the hydraulic cylinders and wherein the controller is configured to: receive control information to move the tool in a direction along a working line; receive position information for the first cylinder; receive position information for the second cylinder; determine if the working line for the tool is maintained, and, if the working line is not maintained, then adapt for the movement of the first cylinder by providing control of the second cylinder to maintain the working line for the tool and thereby feeding the tool along the working line.