Self-diagnostic accelerometer with symmetric proof-mass and its preparation method

• US 5,777,227 A
• Filed: 10/06/1995
• Issued: 07/07/1998
• Est. Priority Date: 10/07/1994
• Status: Expired due to Fees

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group), Korea Advanced Institute of Science and Technology
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group), Korea Advanced Institute of Science and Technology
• Inventors: Cho, Young-Ho, Kwak, Byung Man, Lee, Kwyro, Park, Kwanhum
• Primary Examiner(s): Williams, Hezron E.
• Assistant Examiner(s): MOLLER, RICHARD ALAN
• Application Number:
  US08/539,521
• Time in Patent Office: 1,005 Days
• Field of Search: 73/514.36, 73/514.38, 73/522, 73/514.32, 73/514.33, 73/514.34, 73/514.05, 73/514.12, 73/514.01
• US Class Current: 73/514.38
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/09 by piezoelectric pick-up
• CPC Class Codes: G01P 15/0922 of the bending or flexing mode type
• CPC Class Codes: G01P 15/123 by piezo-resistive elements, e.g. semiconductor strain gauges
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 2015/0828 the mass being of the paddle type being suspended at one of its longitudinal ends
• CPC Class Codes: G01P 21/00 Testing or calibrating of apparatus or devices covered by the preceding groups

Abstract

A symmetrical proof-mass accelerometer with a self-diagnosis capability and its fabrication method are disclosed. The accelerometer has symmetrical mass distribution with respect to the plane of the cantilever beam with an offset between upper and lower masses, so as to minimize cross-axis sensitivity and facilitate self-diagnostic resistor installation. This accelerometer can be applied to automobile electronics systems, consumer electronics, and industrial electrical measurement systems, which require measurements of displacement, velocity, vibration, acceleration, angular acceleration and their changes.

Claims

1. A symmetrical proof-mass accelerometer, comprising:

a cantilever beam having a first and second end and having an upper flat surface and a bottom surface with a curved portion at said first and second end;

upper and lower proof-masses supported by said cantilever beam at said first end, said upper and lower proof-masses having a same area and mass;

a supporter supporting said cantilever beam at said second end; and

supporting plates supporting said supporter with damping control gaps formed between said upper and lower proof masses and said supporting plates, said damping control gaps being adjusted to control a damping level of said cantilever beam.

2. The accelerometer of claim 1, wherein said upper and lower proof-masses are symmetrically located with respect to a center plane of the cantilever beam and have an offset such that a center of mass for said upper and lower proof-masses is located on said center plane.