Compensation pendulous accelerometer

• US 6,422,076 B1
• Filed: 06/21/2000
• Issued: 07/23/2002
• Est. Priority Date: 06/23/1999
• Status: Expired due to Term

• Current Assignee: Agency For Defense Development (Government of The Republic of China), Sergei Feodosievich Konovalov
• Original Assignee: Agency For Defense Development (Government of The Republic of China), Sergei Feodosievich Konovalov
• Inventors: Polynkov, Alexei Viktorovich, Konovchenko, Alexandr Afanasievich, Oh, Moon-Su, Seo, Jae-Beom, Kwon, Oh-Sun, Konovalov, Sergei Feodosievich, Chung, Tae-Ho, Prokofiev, Viktor Mikhailovich, Bakhratov, Anufry Rafailovich, Kurnosov, Valery Ivanovich, Trunov, Alexandr Alexandrovich, Larshin, Alexandr Sergeevich, Moon, Hong-Key
• Primary Examiner(s): KWOK, HELEN C
• Application Number:
  US09/598,386
• Time in Patent Office: 762 Days
• Field of Search: 735/142.1, 735/142.2, 735/142.3, 735/142.4, 735/143.8
• US Class Current: 73/514.23
• CPC Class Codes: G01P 15/132 with electromagnetic counterbalancing means

Abstract

A compensation pendulous accelerometer comprises a body in which a pendulous unit is positioned that is made as a unitary plate of a silicon monocrystal and comprises a movable vane on a flexible suspension and a support frame with protrusions. Two magnetic systems are secured on opposite sides of the movable vane and two coils of a torquer are positioned in a clearance of a corresponding core and are secured on a corresponding side of the movable vane. The flexible suspension includes flexible members arranged at an angle of 90 degrees relative to one another, symmetrically relative to an axis of symmetry of the pendulous unit. When the accelerometer is accelerated, the movable vane deflects in the opposite direction of the acceleration, and a current in the coils returns the movable vane to its initial position. A measured amount of current through coils is used to determine the acceleration.

Claims

1. A compensation pendulous accelerometer comprising:

a body;

a pendulous unit positioned in said body, the pendulous unit being made of a unitary plate of a silicon monocrystal and comprising a movable vane on a flexible suspension and further comprising a support frame with protrusions on two sides of the support frame for positioning the movable vane;

first and second electrical insulation members each of which is attached to a respective one of said protrusions on the two sides of said support frame;

a first magnetic system, comprising a first core, a first permanent magnet and a first pole piece;

a third electrical insulation member, on which said first magnetic system is secured;

a second magnetic system, comprising a second core, a second permanent magnet and a second pole piece;

a fourth electrical insulation member, on which said second magnetic system is secured;

a torquer having a first coil with leads and a second coil with leads;

the first coil is positioned in a clearance of said first core and secured on one side of said movable vane;

the second coil is positioned in a clearance of said second core and secured on another side of the movable vane;

said flexible suspension comprising at least two flexible members arranged at an angle of 90 degrees relative to one another, symmetrically relative to an axis of symmetry of said pendulous unit;

each of said third and fourth electrical insulation members is made in the form of a bush that encompasses said first and second cores of said first and second magnetic systems along, an outer side surface of said first and second cores;

said support frame of said pendulous unit having said protrusions positioned on the two sides of the support frame abuts against a respective face of said third and fourth electrical insulation members forming common planes with faces of said cores facing said pendulous unit; and

means for fixing the magnetic systems relative to said pendulous unit, the means for fixing the magnetic systems relative to said pendulous unit being placed on said pendulous unit and on each of said third and fourth electrical insulation members.

2. An accelerometer according to claim 1, which comprises

a mounting means secured in said body and serving to fix said pendulous unit relative to said body,

said first electrical insulation member is rigidly connected to said mounting means.

3. An accelerometer according to claim 1, wherein said means for fixing the magnetic systems relative to the pendulous unit comprises:

a holding bush, having an inner cylindrical surface which is in contact with an outer cylindrical surface of each of said third and fourth electrical insulation members;

a support ring, having an outer cylindrical surface which is in contact with an inner cylindrical surface of said holding bush;

wherein said third electrical insulation member and said fourth electrical insulation member and said pendulous unit are compressed between a collar, made on the inner cylindrical surface of said holding bush, and said support ring;

a first ring secured on one side of said support frame coaxially with said first and second coils;

a second ring secured on another side of said support frame coaxially with said first and second coils; and

each of said first and second rings encompasses a corresponding insulating bush, wherein the first ring is mounted on a corresponding bush without a clearance and the second ring is secured on a corresponding bush with a clearance.

4. An accelerometer according to claim 3, wherein said holding bush and said support ring are made of electrically conducting material,

wherein said accelerometer comprises first and second insulating plates with metallized surfaces on one side,

said an insulating plate is secured with the insulating side on an outer face surface of a corresponding said core,

said second insulating plate is secured with an insulating side on an outer face surface of a corresponding said core, and

said metallized surfaces are electrically connected to said holding bush and said support ring to form an electrostatic screen.

5. An accelerometer according to claim 1, wherein a tip of the 90°

angle between said two flexible members is located on said vane.

6. An accelerometer according to claim 1, wherein a tip of the 90°

angle between said two flexible is located on said support frame.

7. An accelerometer according to claim 1, which further comprises a first additional resilient member and a second additional resilient member,

wherein said first and second additional resilient members and said at least two flexible members of said flexible suspension form a square.

8. An accelerometer according to claim 1, wherein a slot for removing mechanical stresses in said flexible suspension is made in said support frame, to the right or left of the axis of symmetry of said pendulous on the section between securing of said flexible suspension and the closest protrusion.

9. An accelerometer according to claim 3, wherein said first and second rings are made of a material having a coefficient of thermal expansion that is substantially the same as a coefficient of thermal expansion of silicon.

10. An accelerometer according to claim 1, wherein said coils are secured on said vane by means of first and second transition washers each heaving central cylindrical hole,

wherein said first and second pieces of said first and second systems each having a central cylindrical protrusion facing said pendulous unit and entering said central cylindrical holes of said transition washers with a clearance,

the clearance between the cylindrical surface of said protrusion on said first pole piece of said first magnetic system and the cylindrical surface of said central hole of corresponding said transition washer is made much less than the clearance between said coils and said magnetic systems.

11. An accelerometer according to claim 10, wherein said transition washers are made of insulating material and have contact terminals for connecting said leads of the coils of said torquer.