Rotational angle measuring apparatus

• US 6,675,124 B2
• Filed: 01/09/2002
• Issued: 01/06/2004
• Est. Priority Date: 01/18/2001
• Status: Expired due to Fees

• Current Assignee: Niles Parts Co., Ltd. (Valeo SE)
• Original Assignee: Niles Parts Co., Ltd. (Valeo SE)
• Inventors: Koga, Osamu
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): LE, JOHN H
• Application Number:
  US10/041,970
• Publication Number:
  US 20020111763A1
• Time in Patent Office: 727 Days
• Field of Search: 702/41, 702/105, 702/150, 702/151, 702/167, 701/36, 324/165, 324/207.2, 324/207.25, 180/405, 180/446, 280/5.512
• US Class Current: 702/151
• CPC Class Codes: B62D 15/021 Determination of steering angle
• CPC Class Codes: B62D 15/0245 Means or methods for determination of the central position of the steering system, e.g. straight ahead position
• 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 2205/28 The target being driven in rotation by additional gears
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06
• CPC Class Codes: G01D 5/24476 Signal processing G01D5/2448 - G01D5/24495 take precedence

Abstract

Steering angle detecting apparatus of a steering is constituted to dispense with reexecution of initial setting by a simple angle sensor. CPU is connected with an MR sensor attached to a rotating member rotated in cooperation with a steering shaft for detecting a periodic angular position and CPU subjects data from the MR sensor to an operation processing by using a reference position stored to an involatile data storing portion to thereby calculate an absolute steering angle including a number of an order of turns. When an ignition is made OFF, there is constituted a low current consumption mode for carrying out calculation by intermittent operation and power source to the MR sensor is made OFF by a sensor switch. The reference position is stored to the involatile data storing portion and therefore, even after detaching and attaching a battery, initial setting is dispensed with.

Claims

1. A rotational angle measuring apparatus comprising:

a rotating member rotated in cooperation with a rotating body constituting an object of measurement;

an angle sensor attached to the rotating member for detecting a periodic angular portion thereof;

an involatile data storing portion for storing a reference position of the angle sensor; and

operating and controlling means for subjecting the reference position and detected data from the angle sensor to an operational processing to thereby calculate a frequency of the rotating body constituting the object of measurement and calculating an absolute rotational angle of the rotating body constituting the object of measurement to thereby constitute a measured output;

wherein the operating and controlling means switches a mode thereof from a normal operation mode for continuously reading the detected data from the angle sensor and executing the operational processing to a low current consumption mode for executing the operational processing by reading the detected data from the angle sensor by an intermittent operation by receiving a pause signal from outside.

5. The rotational angle measuring apparatus according to any one of claims 1, 2, 3 and 4,

wherein the rotating body constituting the object of measurement is a steering shaft, the measured output is a steering angle and the pause signal is a signal for making an ignition switch off.

6. The rotational angle measuring apparatus according to claim 5,

wherein in the low current consumption mode, a power source is supplied to the angle sensor only in the intermittent operation of the operating and controlling means.

7. The rotational angle measuring apparatus according to claim 5,

wherein the operating and controlling means monitors a voltage of the power source and constitutes the low current consumption mode when the voltage becomes lower than a predetermined voltage.

9. The rotational angle measuring apparatus according to any one of claims 1, 2, 3, 4, and 8,

wherein in the low current consumption mode, a power source is supplied to the angle sensor only in the intermittent operation of the operating and controlling means.

10. The rotational angle measuring apparatus according to any one of claims 1, 2, 3, 4, and 8,

wherein the operating and controlling means monitors a voltage of the power source and constitutes the low current consumption mode when the voltage becomes lower than a predetermined voltage.

11. The rotational angle measuring apparatus according to claim 9,

wherein the operating and controlling means monitors a voltage of the power source and constitutes the low current consumption mode when the voltage becomes lower than a predetermined voltage.

2. A rotational angle measuring apparatus comprising:

a rotating member rotated in cooperation with a rotating body constituting an object of measurement;

a plurality of angle sensors attached to the rotating member for detecting a periodic angular position thereof;

an involatile data storing portion for storing a reference position of the angle sensor; and

operating and controlling means for subjecting the reference position and detected data from the respective angle sensors to an operational processing to thereby calculate a frequency of the rotating body constituting the object of measurement and calculating absolute rotational angles of the rotating body constituting the object of measurement and constituting an average value thereof as a measured output;

wherein the operating and controlling means switches a mode thereof from a normal operation mode for continuously reading the detected data from the angle sensors and executing the operational processing to a low current consumption mode for reading the detected data from the angle sensors and executing the operational processing by an intermittent operation by receiving a pause signal from outside.

3. The rotational angle measuring apparatus according to claim 2,

wherein when a difference between the absolute rotational angles based on the rotational angles detected by the respective angle sensors is larger than a predetermined value, the operating and controlling means determines that an abnormality is caused.

4. The rotational angle measuring apparatus according to claim 2,

wherein when there is present an absolute rotational angle in which a difference between said absolute rotational angle and an average value of the absolute rotational angles based on the rotational angles detected by the respective angle sensors is larger than a predetermined value, the measured output is constituted by an average value of the other absolute rotational angles excluding said absolute rotational angle.

8. The rotational angle measuring apparatus according to claim 3,

wherein the rotating body constituting the object of measurement is a steering shaft of a vehicle, when an abnormality is determined to cause, the operating and controlling means calculates a range of a steering angle based on a signal from a sensor for detecting a behavior of the vehicle and outputs the steering angle as the measured output based on the absolute rotational angle produced by excluding the absolute rotational angle deviated from the range of the steering angle.

12. A rotational angle measuring apparatus comprising:

a rotating member rotated in cooperation with a rotating body constituting an object of measurement;

an angle sensor attached to the rotating member for detecting a periodic angular portion thereof;

an involatile data storing portion for storing a reference position of the angle sensor; and

operating and controlling means for subjecting the reference position and detected data from the angle sensor to an operational processing to thereby calculate a frequency of the rotating body constituting the object of measurement and calculating an absolute rotational angle of the rotating body constituting the object of measurement to thereby constitute a measured output;

wherein the operating and controlling means switches a mode thereof from a normal operation mode for continuously reading the detected data from the angle sensor and executing the operational processing to a low current consumption mode for executing the operational processing by reading the detected data from the angle sensor by an intermittent operation by receiving a pause signal from outside;

the rotating body constituting the object of measurement is a steering shaft, the measured output is a steering angle and the pause signal is a signal for making an ignition switch off; and

the operating and controlling means sets a frequency to null by an angular position when the vehicle is determined to be brought into a linearly advancing state based on a signal from a sensor for detecting a behavior of the vehicle when a power source has been removed and thereafter connected again.

16. The rotational angle measuring apparatus according to any one of claims 12, 13, 14, and 15

wherein in the low current consumption mode, a power source is supplied to the angle sensor only in the intermittent operation of the operating and controlling means.

17. The rotational angle measuring apparatus according to any one of claims 12, 13, 14, and 15,

wherein the operating and controlling means monitors a voltage of the power source and constitutes the low current consumption mode when the voltage becomes lower than a predetermined voltage.

13. A rotational angle measuring apparatus comprising:

a rotating member rotated in cooperation with a rotating body constituting an object of measurement;

a plurality of angle sensors attached to the rotating member for detecting a periodic angular position thereof;

an involatile data storing portion for storing a reference position of the angle sensor; and

operating and controlling means for subjecting the reference position and detected data from the respective angle sensors to an operational processing to thereby calculate a frequency of the rotating body constituting the object of measurement and calculating absolute rotational angles of the rotating body constituting the object of measurement and constituting an average value thereof as a measured output;

wherein the operating and controlling means switches a mode thereof from a normal operation mode for continuously reading the detected data from the angle sensors and executing the operational processing to a low current consumption mode for reading the detected data from the angle sensors and executing the operational processing by an intermittent operation by receiving a pause signal from outside;

the rotating body constituting the object of measurement is a steering shaft, the measured output is a steering angle and the pause signal is a signal for making an ignition switch off; and

the operating and controlling means sets a frequency to null by an angular position when the vehicle is determined to be brought into a linearly advancing state based on a signal from a sensor for detecting a behavior of the vehicle when a power source has been removed and thereafter connected again.

14. A rotational angle measuring apparatus comprising:

a rotating member rotated in cooperation with a rotating body constituting an object of measurement;

a plurality of angle sensors attached to the rotating member for detecting a periodic angular position thereof;

an involatile data storing portion for storing a reference position of the angle sensor; and

operating and controlling means for subjecting the reference position and detected data from the respective angle sensors to an operational processing to thereby calculate a frequency of the rotating body constituting the object of measurement and calculating absolute rotational angles of the rotating body constituting the object of measurement and constituting an average value thereof as a measured output;

wherein the operating and controlling means switches a mode thereof from a normal operation mode for continuously reading the detected data from the angle sensors and executing the operational processing to a low current consumption mode for reading the detected data from the angle sensors and executing the operational processing by an intermittent operation by receiving a pause signal from outside;

when a difference between the absolute rotational angles based on the rotational angles detected by the respective angle sensors is larger than a predetermined value, the operating and controlling means determines that an abnormality is caused;

the rotating body constituting the object of measurement is a steering shaft, the measured output is a steering angle and the pause signal is a signal for making an ignition switch off; and

the operating and controlling means sets a frequency to null by an angular position when the vehicle is determined to be brought into a linearly advancing state based on a signal from a sensor for detecting a behavior of the vehicle when a power source has been removed and thereafter connected again.

15. A rotational angle measuring apparatus comprising:

a rotating member rotated in cooperation with a rotating body constituting an object of measurement;

a plurality of angle sensors attached to the rotating member for detecting a periodic angular position thereof;

an involatile data storing portion for storing a reference position of the angle sensor; and

operating and controlling means for subjecting the reference position and detected data from the respective angle sensors to an operational processing to thereby calculate a frequency of the rotating body constituting the object of measurement and calculating absolute rotational angles of the rotating body constituting the object of measurement and constituting an average value thereof as a measured output;

wherein the operating and controlling means switches a mode thereof from a normal operation mode for continuously reading the detected data from the angle sensors and executing the operational processing to a low current consumption mode for reading the detected data from the angle sensors and executing the operational processing by an intermittent operation by receiving a pause signal from outside;

when there is present an absolute rotational angle in which a difference between said absolute rotational angle and an average value of the absolute rotational angles based on the rotational angles detected by the respective angle sensors is larger than a predetermined value, the measured output is constituted by an average value of the other absolute rotational angles excluding said absolute rotational angle;

the rotating body constituting the object of measurement is a steering shaft, the measured output is a steering angle and the pause signal is a signal for making an ignition switch off; and

the operating and controlling means sets a frequency to null by an angular position when the vehicle is determined to be brought into a linearly advancing state based on a signal from a sensor for detecting a behavior of the vehicle when a power source has been removed and thereafter connected again.