ROTATION ANGLE DETECTION APPARATUS

• US 20100250184A1
• Filed: 03/06/2009
• Published: 09/30/2010
• Est. Priority Date: 03/18/2008
• Status: Abandoned Application

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Takenaga, Fumitaka, Mori, Takeshi, Miyoshi, Sotsuo, Kawamura, Satoshi, Inoue, Masaya, Iezawa, Masahiro, Onishi, Yoshitaka
• Application Number:
  US12/746,219
• Publication Number:
  US 20100250184A1
• Time in Patent Office: Days
• US Class Current: 702/151
• CPC Class Codes: G01D 2205/26 Details of encoders or position sensors specially adapted to detect rotation beyond a full turn of 360°, e.g. multi-rotation
• CPC Class Codes: G01D 2205/80 Manufacturing details of magnetic targets for magnetic encoders
• CPC Class Codes: G01D 2205/85 Determining the direction of movement of an encoder, e.g. of an incremental encoder
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06

Abstract

An arithmetic processing means detects a change in a rotation angle of one or more rotations from the direction of a change in the sign of one of sensor output signals and the sign of the other sensor output signal, and generates multiple rotation angle information from information about the detected change in the rotation angle of one or more rotations and rotation angle information about one rotation calculated from the sensor output signals.

Claims

1. A rotation angle detection apparatus which determines a rotation angle by using a vector from two sine wave shaped sensor output signals which are out of phase with each other, wherein said rotation angle detection apparatus comprises:

an arithmetic processing means for detecting a change in a rotation angle of one or more rotations from a direction of a change in a sign of one of said two sensor output signals and a sign of the other one of said two sensor output signals, and for generating multiple rotation angle information from information about said detected change in the rotation angle of one or more rotations and rotation angle information about one rotation calculated from said sensor output signals.

2. The rotation angle detection apparatus according to claim 1, wherein said arithmetic processing means converts said sensor output signals into digital values, compares the signals whose amplitude and offset have been corrected with a preset zero reference value to carry out edge detection, counts a pulse which is outputted on a basis of conditions of normal or reverse rotation in n rotations (n is an arbitrary integer) to use the pulse as a rotation number identification signal, and generates said multiple rotation angle information by combining with the rotation angle information about one rotation which is calculated from said sensor output signals.

3. The rotation angle detection apparatus according to claim 1, wherein when a region from a start point of an operation region to an end point of the operation region is defined as a rotation angle full stroke θ

, said arithmetic processing means generates the multiple rotation angle information by defining a position which is shifted forwardly from 0 degrees by δ

1 as a start point of arrangement of absolute value outputs of the sensor signals, and also defining a position which is shifted backwardly from 720 degrees by δ

2 as an end point of the arrangement, setting each of δ

1 and δ

2 to a value equal to or larger than a rotation detection error region, and simultaneously making θ

satisfy θ

<

720 degrees−

(δ

1+δ

2).

4. A rotation angle detection apparatus which determines a rotation angle by using a vector from two sine wave shaped sensor output signals which are out of phase with each other, wherein said rotation angle detection apparatus comprises:

an arithmetic processing means for generating signals of two phases each having an arbitrary number of divisions per one rotation, the signals of two phases being out of phase with each other, from rotation angle information about one rotation which is calculated from said two sine wave shaped sensor output signals which are out of phase with each other, and for increasing or decreasing a number of times that said signals of two phases vary according to directions of changes in said signals and magnitudes of the signals.

5. The rotation angle detection apparatus according to claim 4, wherein said arithmetic processing means defines binary digital signals as the signals of two phases generated from said rotation angle information about one rotation, each the signals having an arbitrary number of divisions per one rotation and the signals being out of phase with each other.

6. The rotation angle detection apparatus according to claim 4, wherein said arithmetic processing means generates the binary digital signal from two arbitrary contiguous bit signals of said rotation angle information about one rotation.

7. The rotation angle detection apparatus according to claim 4, wherein said arithmetic processing means sets an original position arbitrarily according to a reset signal furnished thereto from outside the rotation angle detection apparatus.