A ground surface estimation method include: performing first estimation in which the continuous region having a largest number of the grids among the continuous regions is estimated as a ground surface; and performing second estimation including: calculating an average altitude value of the representative point of the grids in the non-adjacent continuous region for each of the non-adjacent continuous regions; calculating an average altitude value of the representative point of the grids in the predetermined range of the continuous region estimated as the ground surface; and estimating that a non-adjacent continuous region as the ground surface when a difference between the average altitude value of the representative point of the grids in the non-adjacent continuous region and the average altitude value of the representative point of the grids in a predetermined range of the continuous region estimated as the ground surface is equal to or less than a threshold.

A ground surface estimation method include: performing first estimation in which the continuous region having a largest number of the grids among the continuous regions is estimated as a ground surface; and performing second estimation including: calculating an average altitude value of the representative point of the grids in the non-adjacent continuous region for each of the non-adjacent continuous regions; calculating an average altitude value of the representative point of the grids in the predetermined range of the continuous region estimated as the ground surface; and estimating that a non-adjacent continuous region as the ground surface when a difference between the average altitude value of the representative point of the grids in the non-adjacent continuous region and the average altitude value of the representative point of the grids in a predetermined range of the continuous region estimated as the ground surface is equal to or less than a threshold.

Tower crane (1) comprising a tower (2) on which a rotating portion (3) is pivotally mounted and configurable between a service configuration in which the rotating portion can be rotatably driven by means of a motorized orientation system (40), and an out of service configuration in which the rotating portion is rotatably released to be able to be oriented in the direction of the wind, where a control/command unit (5) activates a monitoring mode in the out of service configuration to detect, depending on variations in the angle of orientation or the angular speed of the rotating portion, if the rotating portion is in one of the following instability states: an autorotation state corresponding to a rotary movement of the rotating portion in a given direction over at least one complete turn; or an oscillation state corresponding to a back and forth movement of the rotating portion about the orientation axis.

Tower crane (1) comprising a tower (2) on which a rotating portion (3) is pivotally mounted and configurable between a service configuration in which the rotating portion can be rotatably driven by means of a motorized orientation system (40), and an out of service configuration in which the rotating portion is rotatably released to be able to be oriented in the direction of the wind, where a control/command unit (5) activates a monitoring mode in the out of service configuration to detect, depending on variations in the angle of orientation or the angular speed of the rotating portion, if the rotating portion is in one of the following instability states: an autorotation state corresponding to a rotary movement of the rotating portion in a given direction over at least one complete turn; or an oscillation state corresponding to a back and forth movement of the rotating portion about the orientation axis.

A ground surface estimation method includes: a continuous region recognizing step for recognizing, when a difference in altitude value between a representative point of one grid and a representative point of another adjacent grid out of the plurality of grids is equal to or less than a threshold, the one grid and the other adjacent grid as a continuous region that is a region where the one grid and the other adjacent grid are continuous; and a ground surface estimation step for estimating a continuous region having the largest number of grids among the continuous regions as a ground surface.

A ground surface estimation method includes: a continuous region recognizing step for recognizing, when a difference in altitude value between a representative point of one grid and a representative point of another adjacent grid out of the plurality of grids is equal to or less than a threshold, the one grid and the other adjacent grid as a continuous region that is a region where the one grid and the other adjacent grid are continuous; and a ground surface estimation step for estimating a continuous region having the largest number of grids among the continuous regions as a ground surface.

A system and method are disclosed for building a modular electrical system for a jack up rig, the method including but not limited to identifying rig equipment on the jack up rig that will be connected to the modular electrical system; selecting electrical equipment to control the rig equipment; placing the electrical equipment in an electrical module; and electrically connecting the electrical equipment to power cables and control cables inside of the electrical module; and testing the electrical equipment inside of the electrical module.

A system and method are disclosed for building a modular electrical system for a jack up rig, the method including but not limited to identifying rig equipment on the jack up rig that will be connected to the modular electrical system; selecting electrical equipment to control the rig equipment; placing the electrical equipment in an electrical module; and electrically connecting the electrical equipment to power cables and control cables inside of the electrical module; and testing the electrical equipment inside of the electrical module.

The present invention provides an automatic deviation correction control method for a hoisting system, comprising the following steps: obtaining a lateral displacement X and an advancing included angle α generated by the deflection of the hoisting system; when the lateral displacement X is not 0 and the advancing included angle α is not 0, determining whether the lateral displacement X and the advancing included angle α satisfy a preset condition; if the lateral displacement X and the advancing included angle α do not satisfy the preset condition, controlling the hoisting system to correct the deviation toward a center line; and if the lateral displacement X and the advancing included angle α satisfy the preset condition, controlling the hoisting system to correct the deviation toward the center line in a reverse direction.

The article transport vehicle includes a travel section, a holding section, an elevating device, an inclination detection device, an inclination adjustment device, and an inclination control device for controlling the inclination adjustment device. The inclination adjustment device is configured to act on a target belt among a plurality of suspension belts to adjust an inclination of the holding section by adjusting a suspension height at which the holding section is held by the target belt. During the lowering of the holding section to the transfer position by the elevating device, the inclination control device executes an adjustment operation during lowering, in which the inclination of the holding section is detected by the inclination detection device, and based on the result of the detection performed by the inclination detection device, the inclination adjustment device is controlled to adjust the inclination of the holding section.