US 12,404,659 B2
Measuring apparatus, measuring method and recording medium
Keita Hamakawa, Tokyo (JP); Yusuke Inoue, Tokyo (JP); Hiroyuki Takahashi, Tokyo (JP); and Takazumi Yamada, Tokyo (JP)
Assigned to JAPAN AVIATION ELECTRONICS INDUSTRY, LIMITED, Tokyo (JP)
Filed by JAPAN AVIATION ELECTRONICS INDUSTRY, LIMITED, Tokyo (JP)
Filed on Aug. 3, 2021, as Appl. No. 17/392,623.
Claims priority of application No. 2020-196616 (JP), filed on Nov. 27, 2020.
Prior Publication US 2022/0170245 A1, Jun. 2, 2022
Int. Cl. E02F 9/26 (2006.01); E21B 47/024 (2006.01); G01C 9/06 (2006.01); G01C 25/00 (2006.01); G01P 15/18 (2013.01); G01V 8/00 (2006.01)
CPC E02F 9/264 (2013.01) [E21B 47/024 (2013.01); G01C 9/06 (2013.01); G01C 25/00 (2013.01); G01P 15/18 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A measuring apparatus for determining an attitude by using acceleration data output from an acceleration sensor having at least three axes and magnetic field data output from a magnetic sensor having at least three axes, the acceleration sensor and the magnetic sensor being arranged in an excavating part of an underground excavator, the measuring apparatus comprising:
a processing circuitry which executes
an attitude estimating processing for determining an attitude of the excavating part based on the acceleration data (Ax, Ay, Az) and the magnetic field data (Mx, My, Mz); and
a phase correction amount calculating processing for calculating an offset between a gravity tool face and a magnetic force tool face, and setting the calculated offset as an estimated offset, wherein
in a state in which the excavating part is stationary,
the attitude estimating processing sets, as an initial value of an estimated offset (TFO), an offset determined from a gravity tool face (gTF) and a magnetic force tool face (mTF) which are determined based on acceleration data (Ax, Ay, Az) and magnetic field data (Mx, My, Mz), and records the estimated offset (TFO) into a memory; and
during rotation of the excavating part, the measuring apparatus sequentially performs the following (1) to (6), and then repeats the sequence starting at (1):
(1) the measuring apparatus acquires the acceleration data (Ax, Ay, Az) and the magnetic field data (Mx, My, Mz),
(2) the attitude estimating processing determines a measured gravity tool face (mgTF) from acceleration data (ax, ay, az) of a gravity component contained in the acceleration data (Ax, Ay, Az) and a measured magnetic force tool face (mmTF) from magnetic field data (Mx, My, Mz),
(3) the attitude estimating processing obtains a phase correction amount (pdm) as pdm=mmTF−mgTF−TFO and corrected magnetic field data (mx, my, mz) by correcting the magnetic field data (Mx, My, Mz) with the phase correction amount (pdm),
(4) the attitude estimating processing determines the attitude based on the acceleration data (ax, ay, az) and the corrected magnetic field data (mx, my, mz),
(5) the phase correction amount calculating processing calculates an estimated offset (TFO) from the attitude determined by the attitude estimating processing, and
(6) the phase correction amount calculating processing updates the estimated offset (TFO) recorded in the memory.