The resonant frequency x(n) of horizontal shaking of a suspended load W suspended from the distal end of a telescopic boom 9 via wire ropes 1416 is calculated on the basis of the suspension length Lm(n)Ls(n) of the wire ropes 1416; the characteristic frequency y(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 x(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 y(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 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.

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.

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.

A manipulator for concrete pumps having an articulated boom with at least two boom arms and a hydraulic drive that pivots one or more of the boom arms. A hydraulic cylinder has piston and rod side working volumes. A hydraulic circuit has a first switching state in which the hydraulic circuit connects a first working port for feed or discharge of hydraulic fluid to the rod-side working volume and connects a second working port for feed or discharge of hydraulic fluid to the piston-side working volume. In a second switching state, the hydraulic circuit separates the first working port from the first fluid channel and thereby connects the first fluid channel to the second fluid channel for the feed of hydraulic fluid from the rod-side to the piston side working volume. A sensor acquires an operating state variable based upon which an activation assembly sets the switching state.

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 crane calculates the resonance frequency of the fluctuation of a suspended load determined from the hanging length of a main wire rope or a sub wire rope, generates a control signal for actuators, in accordance with the operation of a turning operation tool, a hoisting operation tool and the like, and generates a filtering control signal for the actuators in which a frequency component in any frequency range has been attenuated from the control signal at any ratio in reference to the resonance frequency. When the actuators are controlled by the operation of the respective operation tool and when the actuators are controlled regardless of the operation of the respective operation tool, the frequency range to be attenuated and the attenuation ratio are switched to different settings.

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.

This crane is provided with: a operable functional part that is supported on a pair of lower bases; a driving device; a detection unit that detects information about the attitude of the operable functional part; a target signal generation unit that generates a target signal regarding the moving direction and the moving speed of a suspended load on the basis of information about an operation input for instructing the moving direction and the moving speed of the suspended load; a filter unit that generates a filtering target signal by filtering the target signal; a control signal generation unit that generates a speed control signal for controlling the operation speed of the driving device on the basis of the information about the attitude and the filtering target signal; and a control unit that controls the driving device on the basis of the speed control signal.