A hydraulic system (600) and method for reducing boom dynamics of a boom (30), while providing counter-balance valve protection, includes a hydraulic cylinder (110), first and second counter-balance valves (300, 400), and first and second control valves (700, 800). A net load (90) is supported by a first chamber (116, 118) of the hydraulic cylinder, and a second chamber (118, 116) of the hydraulic cylinder may receive fluctuating hydraulic fluid flow from the second control valve to produce a vibratory response (950) that counters environmental vibrations (960) on the boom. The first control valve may apply a holding pressure and thereby hold the first counter-balance valve closed and the second counter-balance valve open.

A hydraulic system (600) and method for reducing boom dynamics of a boom (30), while providing counter-balance valve protection, includes a hydraulic cylinder (110), first and second counter-balance valves (300, 400), first and second control valves (700, 800), and a selection valve set (850). The selection valve set is adapted to self-configure to a first configuration and to a second configuration when a net load (90) is supported by a first chamber (116, 118) and a second chamber (118, 116) of the hydraulic cylinder, respectively. When the selection valve set is enabled in the first and second configurations, the second and first control valve may fluctuate hydraulic fluid flow to the second and first chamber, respectively, to produce a vibratory response (950) that counters environmental vibrations (960) of the boom. When the selection valve set is not enabled, the first and second counter-balance valves are adapted to provide the hydraulic cylinder with conventional counter-balance valve protection.

A control method for a handling system includes when a trolley is loaded at a target location by a target loading, matching by a crane controller the target location of the trolley on a crossmember with a target location of a load handling point on the substrate, such that a target load is lowered onto the target location of the load handling point, when the target load is lowered at the target location of the trolley, positioning the trolley at the target location by the crane controller, subsequently lowering the target load onto the load handling point by the crane controller and positioning the load handling point at the target location before the target load is lowered onto the load handling point, when the load handling point is movable on the substrate and the load handling point is controlled by the crane controller.

A large manipulator includes a boom arm with a turntable and a plurality of boom segments, which are configured to be pivoted at respective articulation joints with respect to an adjacent boom segment or the turntable. The boom arm further includes at least one inertial sensor configured to measure inclination and/or acceleration of at least one of the plurality of boom segments.

The disclosure relates to a mobile crane, in particular an rough terrain crane, comprising a boom mounted so as to be pivotable about a horizontal pivot axis, a hydraulic luffing cylinder by means of which the boom can be luffed up and down about the pivot axis, a hydraulic control block for controlling the luffing cylinder and a first safety valve which is connected between the control block and the luffing cylinder and is configured to seal off a load-bearing cylinder chamber of the luffing cylinder in a blocking position. According to the disclosure, the crane further comprises a second safety valve, which is connected in series between the first safety valve and the control block and is configured to seal off the load-bearing cylinder chamber of the luffing cylinder in a blocking position.

The present invention provides a dynamic lift-off control device and a crane with which it is possible to quickly perform dynamic lift-off of a suspended load while suppressing vibration of the load. This dynamic lift-off control device D comprises: a boom (14); a winch (13); a load weight measurement means (22); and a controller (40) serving as a control unit, the controller (40) controlling operations of the boom (14) and the winch (13), deriving, when performing dynamic lift-off of the suspended load by hoisting the winch (13), an amount of change in a derricking angle of the boom (14) on the basis of the time change in the measured load weight, and raising the boom (14) so as to compensate for the amount of change.

A hydraulic system (600) and method for reducing boom dynamics of a boom (30), while providing counter-balance valve protection, includes a hydraulic actuator (110), first and second counter-balance valves (300, 400), first and second independent control valves (700, 800), and first and second blocking valves (350, 450). The actuator includes first and second corresponding chambers. In a first mode, the second counter-balance valve is opened by the first control valve, and the first counter-balance valve is opened by the second control valve. In a second mode, at least one of the counter-balance valves is closed. A meter-out control valve (800, 700) may be operated in a flow control mode, and/or a meter-in control valve (700, 800) may be operated in a pressure control mode. Boom dynamics reduction may occur while the boom is in motion (e.g., about a worksite). By opening the counter-balance valves, sensors at the control valves may be used to characterize external loads. The control valves may respond to the external loads and at least partially cancel unwanted boom dynamics. The system may further detecting faults in actuators with counter-balance valves and prevent any single point fault from causing a boom falling event and/or mitigate such faults.

A method for controlling an aerial apparatus with a telescopic boom, strain gauge sensors for detecting the bending state of the telescopic boom in horizontal and vertical directions, a gyroscope attached to the top of the telescopic boom and a control arrangement for controlling movement of the aerial apparatus on the basis of signal values gained from the sensors and the gyroscope, the method including the following steps: obtaining raw signals from the sensors and the gyroscope, calculating reference signals from the raw signals, reconstructing a first oscillation mode and a second oscillation mode from the reference signals and additional model parameters related to construction of the aerial apparatus, calculating a compensation angular velocity value from the reconstructed oscillation modes, and adding the calculated compensation angular velocity value to a feedforward angular velocity value to result in a drive control signal.

For load compensation, different kinds of elastomeric load compensators are placed at various locations on the crane for increased flexibility and for shock and vibration absorption. The elastomeric load compensators employ elastomeric tension elements, elastomeric torsion elements, or elastomeric shear elements. Elastomeric tension elements can be simply inserted in series with the main hoist rope. An elastomeric load compensator employing elastomeric torsion elements is mounted to the underside of the boom for receiving the live end of the main hoist rope. A single stack of elastomeric shear elements is suitable for mounting a hoist or winch or an idler sheave to the crane structure. For additional load compensation, the hoist, winch, and idler sheaves are mounted on rails for increased displacements under heave loads, and the increased displacements are compensated by elongated elastomeric tension elements or multiple elastomeric tension, torsion or shear elements in series.

An active vibration absorber is provided for damping vibrations of a cantilevered portion of a support structure. The vibration absorber comprises a mass, a drive and a control device. The mass is coupled without using a spring and through the drive to a fastening means for fastening the drive to the support structure, so that upon a movement of the mass relative to the fastening means an inertial force caused by this movement is directly transmitted through the drive to the fastening means. The control device comprising a motion sensor is adapted to control the drive in function of a signal from the motion sensor. The active vibration absorber is designed to damp especially low-frequency vibrating structures including more than one mass-spring element so that the vibration amplitude thereof is significantly reduced.