Hitachi Construction Machinery Co., Ltd.

Jinichi Yamaguchi

Mariko Mizuochi

Akinori Ishii

To provide a work machine with high stability in which a dynamic balance can be evaluated easily while the influence of a sudden stop of an travel base, an upperstructure and a work front is taken into consideration. A stabilization control calculation unit () and a command value generating unit () are provided in a control device () of the work machine. The stabilization control calculation unit () uses a sudden stop model and position information of each movable portion of the travel base and a machine body including the work front () to predict a change of stability until reaching a complete stop when a control lever () in an operating state is instantaneously brought back to a stop command position, and calculates a motion limit needed to prevent destabilization from occurring at any time instant until reaching the stop. The command value generating unit () corrects the command information to a drive actuator on the basis of the calculation result of the stabilization control calculation unit ().

Work machine

Disclosed is a working machine that computes and displays moment by moment its dynamic stability and its state of contact with a ground in view of an inertia force and an external force applied to the working machine. Specifically, a working machine is provided with an undercarriage, a working machine main body mounted on the undercarriage, a front working mechanism attached pivotally in an up-and-down direction to the working machine main body, and a working attachment connected to a free end of the front working mechanism. The working machine includes a ZMP computing means for calculating coordinates of a ZMP by using position information, acceleration information and external force information on respective movable portions of the main body, which includes the front working mechanism, and undercarriage, and a stability computing means for calculating a support polygon formed by plural ground points of the working machine with a ground, and, when the ZMP is included in a warning region formed inside a perimeter of the support polygon, producing a tipping warning sound. The ZMP and the support polygon, which includes the warning region, is computed, and a display or warning is produced.

Operation machine

Disclosed is a safety system for a working machine, which allows an operator to instantaneously, readily and precisely recognize current stability during work including operations of a front working mechanism and swing operations. In a safety system for a working machine, a controller is provided with a ZMP calculating means () for calculating coordinates of a ZMP by using position information, acceleration information and external force information on respective movable portions of a main body, which includes a front working mechanism, and undercarriage, and a stability computing means () for calculating a support polygon formed by plural ground contact points of the working machine with a ground, and, when the ZMP is included in a warning region formed inside a perimeter of the support polygon, producing a tipping warning; the safety system is provided with a display () for displaying a top plan view of the working machine and a ZMP position of the working machine relative to the support polygon; the ZMP calculating means and stability computing means compute and display the ZMP position and the support polygon including the warning region therein; and the safety system produces a tipping warning when the calculated ZMP position is included in the warning region formed inside the perimeter of the support polygon.

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Hino, Japan

Jinichi Yamaguchi