Position detecting device
AssigneeSMC Corporation
InventorsKiyoshi Hashimoto, Katsuhisa Endo
Life of this patent
Estimating the term…
Abstract
At a time that a position detecting device is initiated, an arithmetic processing unit calculates the absolute position of a rotating shaft at the time of initiation, on the basis of first to third analog signals corresponding to first to third angles of rotation, which are detected respectively by first to third rotational angle detectors. During rotation of the rotating shaft, a current position counter detects a current absolute position of the rotating shaft by counting a number of pulses of forward rotation pulses or reverse rotation pulses, corresponding to the first angle of rotation detected by the first rotational angle detector, taking as a standard a total number of pulses corresponding to the absolute position of the rotating shaft at the time of initiation.
Claims12
A position detecting device including a speed reducing mechanism connected to a rotating shaft of a rotating body, and configured to detect an absolute position of the rotating shaft, on a basis of an angle of rotation of the rotating shaft and an angle of rotation of an output shaft of the speed reducing mechanism, comprising:
- a first rotational angle detector configured to detect a first angle of rotation in a pitch interval of a gear attached substantially coaxially to the rotating shaft;
- a second rotational angle detector configured to detect a second angle of rotation lying within one rotation of the rotating shaft;
- a third rotational angle detector configured to detect a third angle of rotation lying within one rotation of the output shaft and corresponding to multiple rotations of the rotating shaft;
- an arithmetic processing unit configured to calculate an absolute position of the rotating shaft at a time of initiation of the position detecting device, on a basis of the first to third angles of rotation detected respectively by the first to third rotational angle detectors at the time of initiation;
- and
- a current position detecting unit configured to detect a current absolute position of the rotating shaft during rotation of the rotating shaft upon driving of the rotating body, on a basis of the first angle of rotation detected by the first rotational angle detector, and the absolute position of the rotating shaft at the time of initiation.
A position detecting device including a speed reducing mechanism connected to a rotating shaft of a rotating body, and configured to detect an absolute position of the rotating shaft, on a basis of an angle of rotation of the rotating shaft and an angle of rotation of an output shaft of the speed reducing mechanism, comprising:
- a first rotational angle detector configured to detect a first angle of rotation lying within one rotation of the rotating shaft;
- a second rotational angle detector configured to detect a second angle of rotation lying within one rotation of the output shaft and corresponding to multiple rotations of the rotating shaft;
- an arithmetic processing unit configured to calculate an absolute position of the rotating shaft at a time of initiation of the position detecting device, on a basis of the first angle of rotation and the second angle of rotation detected respectively by the first rotational angle detector and the second rotational angle detector at the time of initiation;
- and
- a current position detecting unit configured to detect a current absolute position of the rotating shaft during rotation of the rotating shaft upon driving of the rotating body, on a basis of the first angle of rotation detected by the first rotational angle detector, and the absolute position of the rotating shaft at the time of initiation,
- wherein the first rotational angle detector comprises a cylindrical bias magnet which is substantially coaxially attached to the rotating shaft, and a magnetic detecting element which is arranged in facing relation to the bias magnet, and
- the magnetic detecting element is configured to output to the arithmetic processing unit a serial signal corresponding to the first angle of rotation, and further output to the current position detecting unit two-phase pulse signals which correspond to the first angle of rotation and whose phases are shifted mutually by 90°.
A position detecting device including a speed reducing mechanism connected to a rotating shaft of a rotating body, and configured to detect an absolute position of the rotating shaft, on a basis of an angle of rotation of the rotating shaft and an angle of rotation of an output shaft of the speed reducing mechanism, comprising:
- a first rotational angle detector configured to detect a first angle of rotation lying within one rotation of the rotating shaft;
- a first speed reducing mechanism configured to decelerate and output a rotational speed of the rotating shaft;
- a second speed reducing mechanism including an input shaft connected to the first speed reducing mechanism, and configured to further decelerate the rotational speed of the rotating shaft which has been decelerated by the first speed reducing mechanism and to output the further decelerated rotational speed to the output shaft;
- a second rotational angle detector configured to detect a second angle of rotation lying within one rotation of the input shaft and corresponding to multiple rotations of the rotating shaft;
- a third rotational angle detector configured to detect a third angle of rotation lying within one rotation of the output shaft and corresponding to the multiple rotations of the rotating shaft;
- an arithmetic processing unit configured to calculate an absolute position of the rotating shaft at a time of initiation of the position detecting device, on a basis of the first to third angles of rotation detected respectively by the first to third rotational angle detectors at the time of initiation;
- and
- a current position detecting unit configured to detect a current absolute position of the rotating shaft during rotation of the rotating shaft upon driving of the rotating body, on a basis of the first angle of rotation detected by the first rotational angle detector, and the absolute position of the rotating shaft at the time of initiation,
- wherein the first rotational angle detector comprises a cylindrical bias magnet which is substantially coaxially attached to the rotating shaft, and a magnetic detecting element which is arranged in facing relation to the bias magnet, and
- the magnetic detecting element is configured to output to the arithmetic processing unit a serial signal corresponding to the first angle of rotation, and further output to the current position detecting unit two-phase pulse signals which correspond to the first angle of rotation and whose phases are shifted mutually by 90°.
Dependencies are inferred from the claim text.