Swiveling work machine and method for detecting orientation of swiveling work machine

Abstract

A swiveling work machine includes: a swivel base rotatable about a swivel axis extending in an up-down direction; a working device provided on the swivel base; a position detector provided on the swivel base to detect a position; and a calculator to calculate an orientation of the swivel base based on a detected position which is the position detected by the position detector, in which the calculator is configured or programmed to calculate an axis position which is a position of the swivel axis based on a plurality of the detected positions obtained during rotation of the swivel base about the swivel axis, and calculate the orientation of the swivel base, based on the axis position and the detected position.

What is claimed is: 
     
         1 . A swiveling work machine comprising:
 a swivel base rotatable about a swivel axis extending in an up-down direction;   a working device provided on the swivel base;   a position detector provided on the swivel base to detect a position; and   a calculator to calculate an orientation of the swivel base based on a detected position which is the position detected by the position detector, wherein   the calculator is configured or programmed to   calculate an axis position which is a position of the swivel axis based on a plurality of the detected positions obtained during rotation of the swivel base about the swivel axis, and   calculate the orientation of the swivel base based on the axis position and the detected position.   
     
     
         2 . The swiveling work machine according to  claim 1 , wherein
 the calculator is configured or programmed to calculate the axis position of the swivel axis based on a plurality of the detected positions obtained during a period from when the swivel base starts the rotation to when the swivel base stops the rotation.   
     
     
         3 . The swiveling work machine according to  claim 1 , further comprising an angle detector provided in or on the swivel base to detect a swivel angle which is an angle of rotation of the swivel base about the swivel axis, wherein
 the calculator is configured or programmed to calculate a current orientation of the swivel base based on a reference orientation and the swivel angle which is an angle of rotation from a swivel position corresponding to the reference orientation to a current swivel position, the reference orientation being the orientation of the swivel base calculated based on the axis position and on one of the plurality of detected positions used to calculate the axis position.   
     
     
         4 . The swiveling work machine according to  claim 3 , wherein
 the calculator is configured or programmed to   calculate the axis position of the swivel axis based on a plurality of the detected positions obtained during a period from when the swivel base starts the rotation to when the swivel base stops the rotation, and   calculate the current orientation of the swivel base based on the reference orientation and on a difference between a swivel angle obtained when the swivel base stops the rotation and a current swivel angle.   
     
     
         5 . The swiveling work machine according to  claim 1 , wherein
 the calculator includes a filter processor configured or programmed to filter the plurality of detected positions obtained during the rotation of the swivel base, and   the filter processor is configured or programmed to exclude one or more of the plurality of detected positions that are located outside a substantially arc-shaped area including an arc having a radius equal to a distance from the swivel axis to the position detected by the position detector.   
     
     
         6 . The swiveling work machine according to  claim 5 , further comprising a tilt detector to detect a tilt angle of the swivel base, wherein
 the filter processor is configured or programmed to correct the area based on the tilt angle detected by the tilt detector.   
     
     
         7 . The swiveling work machine according to  claim 1 , wherein
 the calculator is configured or programmed to calculate a circular or elliptic approximate line based on the plurality of detected positions obtained during the rotation of the swivel base, and calculate the axis position based on the approximate line.   
     
     
         8 . The swiveling work machine according to  claim 7 , wherein
 the calculator is configured or programmed to calculate, using a least squares method using an equation of a circle or an ellipse, the approximate line of the plurality of detected positions obtained during the rotation of the swivel base.   
     
     
         9 . The swiveling work machine according to  claim 1 , further comprising a lower traveling body to travel and to support the swivel base such that the swivel base is rotatable about the swivel axis, wherein
 the calculator is configured or programmed to calculate the axis position based on the plurality of detected positions obtained during the rotation of the swivel base that is performed for the first time after the lower traveling body stops after traveling.   
     
     
         10 . The swiveling work machine according to  claim 1 , wherein
 the position detector is located at a position away from the swivel axis in a horizontal direction.   
     
     
         11 . The swiveling work machine according to  claim 10 , wherein
 the position detector is located at an end portion of the swivel base.   
     
     
         12 . A method of detecting an orientation of a swiveling work machine, comprising:
 a first step including causing a swivel base provided with a working device to rotate about a swivel axis extending in an up-down direction and causing a position detector provided on the swivel base to detect a plurality of detected positions;   a second step including calculating an axis position which is a position of the swivel axis based on the plurality of detected positions detected by the position detector; and   a third step including calculating an orientation of the swivel base based on the axis position calculated in the second step and a current detected position.