US 8,265,897 B2Granted

Rotation angle detector and process for detecting rotation angle

AssigneeFurukawa Electric Co., Ltd.

InventorsFumihiko Abe, Kengo Tanaka, Dongzhi Jin

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Abstract

A rotation angle detection device for detecting the absolute rotation angle of a rotation body rotating multiple times and whose rotation is to be detected. The rotation angles of a first rotation body rotating at a rotation angle frequency in correspondence with rotation of the rotation object whose rotation is to be detected and the rotation angle of a second rotation body rotating at a rotation frequency that is different from the rotation angle frequency of the first rotation body are individually detected. Based on a phase difference between continuous angle signals detected, the rotation speed of a main rotation body, which is either the first or the second rotation body, and the absolute rotation angle of the rotation body rotating multiple times and whose rotation is to be detected is calculated based on the detected continuous angle signal and rotation speed of the main rotation body.

Claims10

Dependent claims

A rotation angle detector for detecting an absolute rotation angle of a detectable rotation body to be rotated a multiple number thereof, comprising:

a first rotation body to be rotated as a cycle of a rotation angle Tc with corresponding to a rotation of the detectable rotation body;
a first detecting unit for detecting the rotation angle of the first rotation body;
a second rotation body to be rotated due to the first rotation body or the detectable rotation body, and to be rotated as a cycle of a rotation angle Tm with corresponding to the rotation of the detectable rotation body, that is different from the cycle of the rotation angle Tc regarding the first rotation body;
a second detecting unit for detecting the rotation angle of the second rotation body;
and
a rotation angle detecting unit for detecting the absolute rotation angle of the detectable rotation body with reference to a first continuous signal for the angle to be detected by using the first detecting unit and to a second continuous signal for the angle to be detected by using the second detecting unit,
wherein the individual rotation bodies is rotated with corresponding to the rotation of the detectable rotation body, and a rotation angle of the detectable rotation body to be rotated in a period of the individual rotation bodies to be rotated as 360 degrees is defined as the individual cycles of the rotation angle respectively;
and
in a case where either one of the first rotation body or the second rotation body is assumed to be as a main rotation body, the other one thereof is assumed to be as a substitutive rotation body, the detecting unit for detecting the rotation angle of the main rotation body is defined as a main detecting unit and the detecting unit for detecting the rotation angle of the substitutive rotation body is defined as a substitutive detecting unit regarding the first detecting unit and the second detecting unit, the rotation angle detecting unit detects a number of rotations regarding the main rotation body with reference to a difference of phases ΔT between the first continuous signal for the angle and the second continuous signal for the angle, and calculates the absolute rotation angle of the detectable rotation body to be rotated the multiple number thereof with reference to the individual continuous signals for the angle and the number of rotations to be detected by using the main detecting unit.

6 more elements

A process for detecting a rotation angle, with comprising a first rotation body to be rotated with corresponding to a rotation of a detectable rotation body to be rotated a multiple number thereof and a second rotation body to be rotated due to the first rotation body or the detectable rotation body, and for detecting an absolute rotation angle of the detectable rotation body, comprising the steps of:

(a) detecting a rotation angle of the first rotation body to be rotated as a cycle of the rotation angle Tc, as a first detection step;
(b) detecting a rotation angle of the second rotation body to be rotated as a cycle of the rotation angle Tm with corresponding to the rotation of the detectable rotation body, that is different from the cycle of the rotation angle Tc regarding the first rotation body, as a second detection step;
and
(c) detecting the absolute rotation angle of the detectable rotation body with reference to a first continuous signal for the angle to be detected at the first detection step (a) and to a second continuous signal for the angle to be detected at the second detection step (b), as a rotation angle detection step,
wherein the individual rotation bodies is rotated with corresponding to the rotation of the detectable rotation body, and a rotation angle of the detectable rotation body to be rotated in a period of the individual rotation bodies to be rotated as 360 degrees is defined as the individual cycles of the rotation angle respectively;
and
in a case where either one of the first rotation body or the second rotation body is assumed to be as a main rotation body, the other one thereof is assumed to be as a substitutive rotation body, the step for detecting the rotation angle of the main rotation body is defined as a main detection step and the step for detecting the rotation angle of the substitutive rotation body is defined as a substitutive detection step, at the rotation angle detection step (c) a number of rotations regarding the main rotation body is detected with reference to a difference of phases ΔT between the first continuous signal for the angle and the second continuous signal for the angle, and the absolute rotation angle of the detectable rotation body to be rotated the multiple number thereof is calculated with reference to the individual continuous signals for the angle and the number of rotations to be detected at the main detection step.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/447,189Filed 28 Sep 2007
Priority: JP 2006-29225227 Oct 2006
Published: US 2010/0185412 A122 Jul 2010
Granted: 11 Sep 2012
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G01B 21/22
Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not…:…
G01B 7/30
Measuring arrangements characterised by the use of electric or magnetic techniques: for measuring angles or tapers; for testing the alignment of axes
G01D 5/145
Using Hall-effect devices: influenced by the relative movement between the Hall device and magnetic fields
G01D 2205/26
Detecting rotary movement: details of encoders or position sensors specially adapted to detect rotation beyond a full turn of 360°, e.g.…