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 control valves (700, 800), and first and second blocking valves (350, 450). A net load (90) is supported by a first chamber (116, 118) of the hydraulic actuator, and a second chamber (118, 116) of the hydraulic actuator 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 blocking valve prevents the fluctuating hydraulic fluid flow from opening the first counter-balance valve. The first blocking valve may drain leakage from the first counter-balance valve.

A dynamic lift-off control device that is mounted on a crane including a boom and a winch for winding a wire rope and that controls dynamic lift-off of a suspended load, wherein: the dynamic lift-off control device comprises a load detection unit that detects a load acting on the boom, and a control unit that controls a winding action of the winch and a hoisting action of the boom; and the control unit controls the hoisting of the boom by using a control signal, which is generated on the basis of the change over time in the value detected by the load detection unit and to which a filter for attenuating a frequency component in a prescribed range, to suppress swaying of the suspended load is applied.

The resonant frequency ωx(n) of horizontal shaking of a suspended load W suspended from the distal end of a telescopic boom 9 via wire ropes 14.Math.16 is calculated on the basis of the suspension length Lm(n).Math.Ls(n) of the wire ropes 14.Math.16; the characteristic frequency ωy(n) in the raising and lowering direction of the telescopic boom 9 is calculated; and, in accordance with an operation for raising and lowering the telescopic boom 9, the filtering control signal Cd(n) of an actuator is generated in which a frequency component in a discretionary frequency range is attenuated at a discretionary ratio with reference to the resonant frequency ωx(n) of the suspended load W, and in which a frequency component in a discretionary frequency range is attenuated at a discretionary ratio with reference to the characteristic frequency ωy(n) in the raising and lowering direction of the telescopic boom 9.

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 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 system for damping mass-induced vibrations in a machine having a long boom or elongate member, the movement of which causes mass-induced vibration in such boom or elongate member. The system comprises multiple pressure sensors operable to measure pressure fluctuations in the hydraulic fluid pressures in the non-load holding and load holding chambers of a hydraulic actuator connected to the boom or elongate member that result from mass-induced vibration, and a processing unit operable to control a first control valve spool in a pressure control mode and a second control valve spool in a flow control mode in order to adjust hydraulic fluid flow to the actuator's load holding chamber to dampen the mass-induced vibration. The system further comprises a control manifold fluidically interposed between the actuator and control valve spools that causes the first and second control valve spools to operate, respectively, in pressure and flow control modes.

This dynamic lift-off control device is mounted in a crane including a boom and a winch that winds a wire rope, the dynamic lift-off control device controlling dynamic lift-off of a suspended load, wherein the dynamic lift-off device comprises a rotation detection unit that detects the rotation speed of the winch, a pressure detection unit that detects a pressure value of a derricking cylinder that raises/lowers the boom, an estimation unit that estimates the derricking angular velocity of the boom on the basis of the respective detection values from the rotation detection unit and the pressure detection unit, and a control unit that controls the derricking operation of the boom on the basis of the estimated value estimated by the estimation unit and a target derricking angular velocity of the boom that is calculated on the basis of the detection value from the pressure detection unit.

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 actuator (110), first and second counter-balance valves (300, 400), first and second control valves (700, 800), and first and second blocking valves (350, 450). A net load (90) is supported by a first chamber (116, 118) of the hydraulic actuator, and a second chamber (118, 116) of the hydraulic actuator 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 blocking valve prevents the fluctuating hydraulic fluid flow from opening the first counter-balance valve. The first blocking valve may drain leakage from the first counter-balance valve.

The invention relates to a crane, in particular a rotary tower crane, comprising a lifting cable configured to run out from a crane boom and comprises a load receiving component, drive devices configured to move multiple crane elements and displace the load receiving component, a controller configured to control the drive devices such that the load receiving apparatus is displaced along a movement path, and a pendulum damping device configured to dampen pendulum movements of the load receiving apparatus and/or of the lifting cable. The pendulum damping device comprises a pendulum sensor system configured to detect pendulum movements of at least one of the lifting cable and the load receiving component and a regulator module comprising a closed control loop configured to influence the actuation of the drive devices depending on a pendulum sensor system signal returned to the control loop.