Detected signal processing device for rotating sensor and detected signal outputting method therefor

• US 6,492,804 B2
• Filed: 12/06/2000
• Issued: 12/10/2002
• Est. Priority Date: 12/07/1999
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Tanabe, Mikio, Tsuge, Hiroyuki
• Primary Examiner(s): Lefkowitz, Edward
• Assistant Examiner(s): KINDER, DARRELL D
• Application Number:
  US09/729,957
• Publication Number:
  US 20010002791A1
• Time in Patent Office: 734 Days
• Field of Search: 324/166, 324/174, 324/207.12, 324/207.2, 324/207.25, 324/165, 303/92, 303/199, 303/122.06, 701/70, 701/71, 188/181.R, 340/671, 340/672
• US Class Current: 324/166
• CPC Class Codes: G01P 13/04 Indicating positive or negative direction of a linear movement or clockwise or anti-clockwise direction of a rotational movement
• CPC Class Codes: G01P 21/02 of speedometers
• CPC Class Codes: G01P 3/487 delivered by rotating magnets

Abstract

The rotation of a rotating magnet is detected by magnetic sensors. The rotational speed is detected from pulse signals detected by magnetic sensors, and the rotational direction is detected from the difference in a shift in phase. Signals different in pulse width are generated according to the rotational direction. A signal selection circuit outputs a pulse signal with timing for the rotational speed. A rotational speed determining circuit outputs a decision signal Sf of a high level when the rotational speed reaches a predetermined speed. When a self-diagnostic circuit determines that the magnetic sensors have malfunctioned, a binary error code generating circuit generates an error signal Sg and a 4-bit error code signal Sh. When the signal Sf of the rotating magnet is brought to a high level, the signal selection circuit outputs an error code signal and allows output an output current Is.

Claims

1. A rotation detecting device, which detects a rotation direction and a rotational speed of a rotor and outputs rotational direction signals having different waveforms according to the rotational direction, said rotational direction signals based on timing corresponding to the detected rotational speed, comprising:

rotational speed determining means for determining whether the rotational speed of the rotor reaches a predetermined rotational speed;

signal pattern generating means for utilizing the rotational signals in combination to generate transfer signals, the transfer signals being encoded with information different from the rotational direction and rotational speed of the rotor; and

signal processing means for signal processing to output a signal generated by the signal pattern generating means with timing corresponding to the rotational speed when a signal generated by the signal pattern generating means exists, where it is determined by the determining means that the rotational speed of the rotor has reached the predetermined rotational speed.

2. The rotation detecting device according to claim 1, further comprising count means for counting a number of rotational direction signals subsequent to a change in rotational direction of the rotor, and wherein the signal processing means processes when the number of the rotational direction signals counted by the count means reaches a predetermined number or more.

3. The rotation detecting device according to claim 1 wherein the rotational direction signals are set such that two pulse signals having different pulse width are associated with normal and reverse rotations of the rotor respectively.

4. The rotation detecting device according to claim 1 wherein the rotational direction signals are set such that two pulse signals having different amplitude are associated with normal and reverse rotations of the rotor respectively.

5. The rotation detecting device according to claim 1 wherein the rotationall direction signals are set with a rectangular pulse signal which is a first pulse signal, and a pulse signal obtained by superimposing a large amplitude identification pulse signal on part of the first pulse signal to form a second pulse signal.

6. The rotation detecting device according to claim 5, wherein the identification pulse signal is set to a leading position of the second pulse signal.

7. The rotation detecting device according to claim 1, wherein each transfer signal is encoded with diagnostic information for the rotating sensor.

8. A rotation detecting device, which detects a rotation direction and a rotational speed of a rotor and outputs rotational direction signals having different waveforms according to the rotation direction, said rotational direction signals based on timing corresponding to the detected rotational speed, said detected signal processing device comprising:

rotational speed determining means for determining whether the rotational speed of the rotor reaches a predetermined rotational speed;

signal pattern generating means for utilizing the rotational direction signals in combination to generate transfer signal having information different from the rotational direction and rotation speed of the rotor; and

signal processing means for signal processing to output a signal generated by the signal pattern generating means with timing corresponding to the rotational speed when a signal generated by the signal pattern generating means exists, where it is determined by the determining means that the rotational speed of the rotor has reached the predetermined rotaional speed. Wherein the signal processing means outputs any one of the rotational direction signals with timing corresponding to the rotational speed when the signals are not generated by the signal pattern generating means where it is determined by the determining means that the rotational speed of the rotor has reached the predetermined rotational speed.

9. The rotation detecting device according to claim 8, wherein the signal processing means sets the rotational direction signal output in where it is determined by the determining means that the rotational speed of the rotor has reached the predetermined rotational speed and when the signals are not generated by the signal pattern generating means, to one reduced in power consumption, of the different rotational direction signals.

10. A rotation detecting outputting method for a rotation detecting sensor, comprising:

outputting rotational direction signals different in waveform according to a rotational direction of a rotor with timing corresponding to a rotational speed of the rotor thereby output information corresponding to the rotational speed and rotational direction of the rotor; and

utilizing the rotational direction signals different in waveform corresponding to the rotational direction in combination on condition that the rotational speed of the rotor reaches a predetermined rotational speed to thereby generate a transfer signal, the transfer signal being encoded with information different from the rotational direction and the rotational speed of the rotor as a signal pattern; and

outputting the generated transfer signal with timing corresponding to the rotational speed.

11. A rotation detecting outputting method for a rotation detecting sensor, comprising:

outputting rotational direction signals different in waveform according to a rotational direction of a rotor with timing corresponding to a rotational speed of the rotor to thereby output information corresponding to the rotational speed and rotational direction of the rotor; and

utilizing the rotational direction signals different in waveform corresponding to the rotational direction in combination on condition that the rotational speed of the rotor reaches a predetermined rotational speed to thereby generate a transfer signal different from the rotational direction and rotational speed of the rotor as a signal pattern; and

outputting the generated one with timing corresponding to the rotational speed.

Wherein when a transfer signal is not generated where transfer signal can be output, either one of the rotational direction signals is output regardless of the rotational direction of the rotor.

12. The rotation detecting outputting method according to claim 11, wherein when a transfer signal to be output is not generated in a state where a transfer signal can be output, the rotational direction signal reduced in power consumption is output regardless of the rotational direction of the rotor.