Method of and an apparatus for detecting control information

• US 5,493,909 A
• Filed: 04/01/1994
• Issued: 02/27/1996
• Est. Priority Date: 01/30/1991
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Araki, Toru
• Primary Examiner(s): Williams, Hezron E.
• Assistant Examiner(s): Oda, Christine K.
• Application Number:
  US08/221,902
• Time in Patent Office: 697 Days
• Field of Search: 73/505, 73/510, 73/511, 73/517 R, 73/517 A, 250/231.16, 250/231.14, 250/231.18
• US Class Current: 73/504.08
• CPC Class Codes: G01P 3/44 for measuring angular speed G01P3/56 takes precedence
• CPC Class Codes: G01P 7/00 Measuring speed by integrating acceleration measuring travelled distance by double integration of acceleration G01C21/16
• CPC Class Codes: H02P 6/17 and for generating speed information

Abstract

The present invention is directed to a method of and an apparatus for detecting an angular velocity and a rotation angle of a rotary member. In the present invention, first and second accelerations at first and second points of the rotary member are detected, respectively. The first and second accelerations are added, while the first acceleration is subtracted from the second acceleration. From the added and subtracted values, then, an angular velocity and a rotary angle of the rotary member are calculated.

Claims

1. A method of detecting control information, comprising the steps of:

detecting first and second accelerations at first and second points of said rotary member, respectively;

subtracting said first and second accelerations to obtain a subtracted value;

calculating a rotation angle of said rotary member on the basis of said subtracted value;

generating a first signal representing said rotation angle using the subtracted value;

generating a first control input based on said first signal; and

controlling a motor disposed to drive said rotary member based upon said first control input.

2. A method in accordance with claim 1, wherein said first and second points are symmetrical with respect to a rotation center of said rotary member and are provided on a surface of said rotary member.

3. A method in accordance with claim 2, wherein said rotary member is disposed so that a normal line to a surface of said rotary member is parallel to the ground.

4. A method in accordance with claim 3, wherein said rotation angle θ

of said rotary member is calculated using the following equation;

##EQU20## where v_- is said subtracted value, k is a coefficient, and g is an acceleration of gravity.

5. A method in accordance with claim 2, wherein said rotary member is disposed so that a normal line to its surface is inclined at an angle of θ

₁ to the ground.

6. A method in accordance with claim 5, wherein said rotation angle θ

of said rotary member is calculated using the following equation;

##EQU21## where v_- is said subtracted value, k is a coefficient, and g is an acceleration of gravity.

7. A method in accordance with claim 2, wherein a detecting direction of said first and second accelerations is inclined at an angle of θ

₂ with respect to a straight line drawn from said rotation center to said first and second point.

8. A method in accordance with claim 7, wherein said rotation angle θ

of said rotary member is calculated using the following equation;

##EQU22## where v_- is said subtracted value, k is a coefficient, and g is an acceleration of gravity.

9. A method in accordance with claim 1, wherein a distance r₁ between said first point and a rotation center of said rotary member is different from a distance r₂ between said second point and said rotation center, while said first point, said rotation center and said second point are aligned in this order.

10. A method in accordance with claim 9, wherein said rotation angle θ

of said rotary member is calculated using the following equation;

##EQU23## where v_- is said subtracted value, k₁ and k₂ are coefficients, and g is an acceleration of gravity.

11. A method in accordance with claim 1, wherein said first point is provided on a surface of said rotary member while said second point is so located that a straight line drawn from said second point to said rotation center is inclined at angle of θ

₄ to said surface.

12. A method in accordance with claim 11, wherein said rotation angle θ

of said rotary member is calculated using the following equation;

##EQU24## where v_- is said subtracted value, k₃ is a coefficient, and g is an acceleration of gravity.

13. A method in accordance with claim 1 further comprises the step of differentiating said subtracted value, to thereby obtain a differentiation value, wherein said calculating step is the step of calculating a rotation angle of said rotary member on the basis of said subtracted value and said differentiation value.

14. A method in accordance with claim 1, comprising:

comparing said first signal with predetermined control instructions; and

generating said first control input based upon said comparing step.

15. An apparatus for detecting control information, comprising:

a rotary member;

a motor for driving said rotary member;

first and second sensors for detecting first and second accelerations at first and second points of said rotary member, respectively;

a subtracter for subtracting said first acceleration from said second acceleration to obtain a subtracted value;

a second computation unit for calculating a rotation angle of said rotary member on the basis of said added value and for outputting a first signal representing said rotation angle; and

a motor control unit for generating a first control input, and controlling said motor on the basis of said first control input.

16. An apparatus in accordance with claim 15 further comprises a differentiation unit for differentiating said subtracted value to thereby obtain a differentiation value, wherein said second calculation unit calculates a rotation angle of said rotary member on the basis of said subtracted value and said differentiation value.

17. An apparatus in accordance with claim 15, wherein said second computational unit comprises:

means for comparing said first signal with predetermined control instructions; and

means for generating said first control input based upon an output of said means for comparing.