Abstract: This expansion device is an expansion device that expands and contracts an boom, the expansion device including: a first hydraulic source that discharges a first working fluid; an expandable cylinder that has a fixed part and a movable part and is operated by the first working fluid; a second hydraulic source that is provided to the movable part, discharges the second working fluid, and is a separate hydraulic source from the first hydraulic source; a first connecting mechanism that is operated by the second working fluid and switches between a connected state and a disconnected state of the first boom element and the movable part; and a second connecting mechanism that is operated by the second working fluid and switches between a connected state and a disconnected state of the first boom element and the second boom element.

Abstract: Provided is a guide display device that prevents misidentification of the same feature as a plurality of different features or the ground surface even if an occlusion area occurs. A guide display device for a crane includes: a laser scanner that scans a suspended load and a ground surface from above the suspended load; and a data processing unit that calculates a representative point for each grid using the point cloud data acquired by the laser scanner, creates a three-dimensional map based on the representative points, and updates the three-dimensional map if the newly calculated representative point differs from the existing representative point. When an occlusion area, which is a shadow of the suspended load, occurs in the three-dimensional map, the occlusion area is not updated even if the newly calculated representative point and the existing representative point are different.

Abstract: This work machine includes: a first hydraulic cylinder and a second hydraulic cylinder that telescope a telescopic boom on the basis of hydraulic oil supply and discharge, a switching valve that is disposed on a pressure relief circuit for connecting the first hydraulic cylinder and the second hydraulic cylinder to a tank, and a control unit that causes the switching valve to connect the first hydraulic cylinder to the tank and releases the pressure in the first hydraulic cylinder when contracting or extending the second hydraulic cylinder in a condition in which the first hydraulic cylinder is contracted.

Abstract: A crane that controls an actuator on the basis of a target speed signal Vd of cargo W includes: a control device having a feedback control unit that calculates a target path signal Pd? of the cargo from the target speed signal Vd by integration to correct the target path signal Pd? on the basis of the differential of current position coordinates p(n) of the cargo W corresponding to the target path signal Pd?; and a feedforward control unit that adjusts a weight coefficient of a transfer function G(s) expressing the characteristics of the crane on the basis of a target path signal Pd1? that has been corrected. The target path signal Pd1? corrected by the feedback control unit is corrected using the transfer function G(s) for which the weight coefficient has been adjusted by the feedforward control unit.

Abstract: A target trajectory signal is calculated by integrating a target speed signal inputted from a suspended-load moving operation tool and passing the integrated signal through a lowpass filter. Target position coordinates of a load are calculated from the target trajectory signal. The current position coordinates of a leading end of a boom are calculated from the attitude of a crane device. An unwinding amount of a wire rope is calculated from the current position coordinates of the load and the current position coordinates of the boom. A direction vector of the wire rope is calculated from the current position coordinates of the load and the target position coordinates of the load. Target position coordinates of the boom are calculated from the unwinding amount and the direction vector. An actuation signal of an actuator is generated from the target position coordinates of the boom.

Abstract: Provided is an estimation apparatus for estimating a number of wound layers of a wire rope in a crane including a boom, a winch drum, and the wire rope wound around the winch drum, the estimation apparatus being mounted on the crane, the estimation apparatus including: a calculation unit that calculates a delivery length of the wire rope; a detection unit that detects a rotational amount of the winch drum; and a control unit that estimates the number of wound layers, based on a difference in the delivery length of the wire rope and a difference in the rotational amount of the winch drum between a first orientation. and a second orientation of the boom.

Abstract: A crane comprising a traveling body and a turning body turnably supported by the traveling body, the crane performing power feeding and communication between the traveling body and the turning body. The traveling body is provided with: a power supply; a lower controller which controls the traveling body and transmits power to the devices included in the traveling body; and a lower transmitter-receiver which wirelessly transmits and receives the power and data signal from the power supply. The turning body is provided with: an upper controller which controls the turning body and transmits power to the devices included in the turning body; and an upper transmitter-receiver which wirelessly transmits and receives the power and data signal to and from the lower transmitter-receiver.

Abstract: A work vehicle includes: an operation tool that is operated by an operator; and a controller that determines a target flow rate for hydraulic oil fed to a hydraulic device on a basis of the amount of operation of the operation tool. The controller calculates a bleed-off target flow rate on a basis of the flow rate of hydraulic oil fed from a hydraulic oil pump and the target flow rate for hydraulic oil fed to the hydraulic device, calculates a bleed-off throttle differential pressure on a basis of a pressure of hydraulic oil fed from the hydraulic oil pump and a pressure of hydraulic oil in a hydraulic oil tank, calculates a bleed-off target opening area on a basis of the bleed-off target flow rate and the bleed-off throttle differential pressure, and controls a hydraulic oil control valve such that the bleed-off target opening area is achieved.

Abstract: This crane is capable of transporting cargo and includes: a feedback control unit for feedback control of the crane or an object to be controlled that is a component of the crane; a learning model that has a weighting factor and learns the characteristics of the object to be controlled in real time by adjusting the weighting factor on the basis of a teacher signal including a first signal generated by the feedback control unit; and a communication control unit that transmits the weighting factor to an external device that is communicatively connected to the crane.

Abstract: This work machine includes: a telescoping actuator that moves a first boom in the telescoping direction with respect to a second boom; an electrical drive source that is disposed in a movable portion of the telescoping actuator; a first connection mechanism that switches a connection state between the telescoping actuator and the first boom on the basis of the power of the electrical drive source; a second connection mechanism that switches a connection state between the first boom and the second boom on the basis of the power of the electrical drive source; and a control device that controls operation of the electrical drive source. The control device executes motor assist processing of operating the electrical drive source when the first fixing pin and/or the second fixing pin is restored by biasing force.

Abstract: A tack welding method and a tack welding apparatus that can improve the strength of a tack-welded joint portion and reduce the height of a reinforcement bead is provided. A tack welding method of the present embodiment is a tack welding method of tack-welding a part of a joint portion of a first joint and a second joint at a predetermined interval before main welding. In the tack welding method, a filler metal is supplied to the joint portion, laser light is deflected and irradiated to the joint portion, and the filler metal is cut with the laser light to be welded to the joint portion.

Abstract: This crane is provided with: a operable function unit; an operation unit; an actuator; a generation unit which generates a first control signal for the actuator on the basis of an operation input; a plurality of wire ropes; a plurality of hooks suspended from a leading end section of a boom by the plurality of wire ropes, respectively; a hook detection unit which detects, from among the plurality of hooks, an unused hook suspending no load; a calculation unit which calculates a resonance frequency for a wire rope, among the plurality of wire ropes, that suspends the detected unused hook; a filter unit which generates a filter on the basis of the resonance frequency and generates a second control signal by filtering the first control signal using the filter; and a control unit which controls the actuator on the basis of the second control signal.

Abstract: A crane vehicle achieves safe movement by reliably detecting an obstacle in a region which is a blind spot from the opposite side of the driver seat across a boom. The crane vehicle includes an obstacle sensor which is a transmission/reception antenna that transmits a detection wave and receives the detection wave reflected from the obstacle. A signal corresponding to the reflected wave received by the obstacle sensor is amplified and input to a controller, which calculates the position and the size of the obstacle on the basis of the signal. The controller generates an obstacle display image and displays the image on a display, the obstacle display image including a vehicle object that represents a crane vehicle and an obstacle object which is an object corresponding to the calculated size of the obstacle and which is disposed at a position corresponding to the calculated position of the obstacle.

Abstract: This dynamic lift-off control device, which is mounted on a crane having a boom and a winch for winding a wire rope and controls dynamic lift-off of a suspended load, comprises: an image-capturing unit that is installed at the tip of the boom and captures an image including a hook; and a control unit that controls a winding action of the winch and a raising action of the boom. The control unit calculates the amount of misalignment between the tip of the boom and the hook on the basis of the image, and feedback controls the raising of the boom to reduce the amount of misalignment, thereby suppressing the swing of the suspended load.

Abstract: There is provided a crane position determination device that is to be mounted on a mobile crane, the crane position determination device including: an input unit that receives input of the working conditions of crane work; a determination unit that has a learning model and determines the placement position of the mobile crane on the basis of output from the learning model; and a notification unit that provides notification of the placement position of the mobile crane, wherein on the basis of a reward function including at least one evaluation function pertaining to the crane work, the learning model learns to output information pertaining to the optimum placement position of the mobile crane with respect to the working conditions.

Abstract: 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.

Abstract: A hybrid welding device capable of reducing an influence of by-products such as spatters, plasma, plumes, and fume, and reducing contamination of a laser optical system and welding defects is provided. A laser head includes a laser nozzle that forms an optical path of a laser beam, a first rectifying plate that is arranged on a tip side of the laser nozzle so as not to interfere with the laser beam, a first air knife that injects compressed air along the first rectifying plate, a second rectifying plate that is arranged between the first rectifying plate and the welded portion so as not to interfere with the laser beam, and a second air knife that injects compressed air along the second rectifying plate. The first rectifying plate and the second rectifying plate have a shape elongated in a direction perpendicular to an optical axis of the laser beam and a welding direction. The second rectifying plate has a torch opening through which a tip of a welding torch can be inserted.

Abstract: The invention addresses the problem of providing a crane and a crane control method that can suppress load swaying when controlling an actuator on the basis of the load.

Abstract: 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.

Abstract: There is provided a method for controlling a crane, with which the position of a hook is automatically adjusted before lift-off, where a freely-derricking telescopic boom is provided to a swivel base, a main hook is suspended with a main wire rope from a distal end section of the telescopic boom, and a suspended load is suspended on a main hook with slinging wire ropes, wherein post-slinging lift-off is preceded by a hook position adjustment control involving repeating: a first process where the control device controls so as to reel in the main wire rope to a position where the main wire rope is tensed; and a second process where the control device controls so as to move the distal end section of the telescopic boom in the same direction of a horizontal direction component of the movement of the main hook in the first process.