Method for the decoupled control of the quadrature and the resonance frequency of a micro-mechanical rotation rate sensor by means of sigma-delta-modulation

Patent metadata

Field	Value
Publication number	US-9535084-B2
Application number	US-201113634585-A
Country	US
Kind code	B2
Filing date	Mar 17, 2011
Priority date	Mar 17, 2010
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

A method for the precise measuring operating of a micro-mechanical rotation rate sensor, including at least one seismic mass, at least one drive device for driving the seismic mass in the primary mode (q 1 ) and at least three trimming electrode elements which are jointly associated directly or indirectly with the seismic mass. An electric trimming voltage (u 1 , u 2 , u 3 , u 4 ) is set respectively between the trimming electrode elements and the seismic mass. Each of the electric trimming voltages (u 1 , u 2 , u 3 , u 4 ) are adjusted in accordance with a resonance frequency variable (ũ T , Ũ T,0 ), a quadrature variable (ũ c , Ũ C,0 ) and a restoring variable (ũ S ).

First claim

The invention claimed is:

1. A method for the precise measuring operation of a micro-mechanical rotation rate sensor, comprising at least one seismic mass, at least one drive device for driving the seismic mass in a primary mode (q 1 ) and at least four trimming electrode elements which are jointly associated directly or indirectly with the seismic mass, wherein in each case an electric trimming voltage (u 1 , u 2 , u 3 , u 4 ) is applied between each of these trimming electrode elements and the seismic mass,
wherein the rotation rate sensor comprises a control arrangement to measure rotation rate, and wherein the control arrangement comprises a sigma-delta converter with which a controlled variable (y) representing the detected deflection of the seismic mass in its secondary mode (q 2 ) is digitized directly or at least a variable dependent thereon is digitized, and after which:
1) a resetting variable (ũ S ) is generated as a digital variable, and
2) both a resonance frequency manipulated variable (ũ T ), and a quadrature manipulated variable (ũ C ) are generated as digital variables based on the digital resetting variable (ũ S ), and

wherein each of the electric trimming voltages (u 1 , u 2 , u 3 , u 4 ) is set as a function of a square root of a different sum of the digitized resonance frequency manipulated variable (ũ T ), the quadrature manipulated variable (ũ C ) and another resetting variable (ũ S ).

2. The method as claimed in claim 1 , wherein the rotation rate sensor comprises at least four trimming electrode elements which are jointly associated directly or indirectly with the seismic mass, wherein a first electric trimming voltage is applied between the first trimming electrode element and the seismic mass, a second trimming voltage is applied between the second trimming electrode element and the seismic mass, a third trimming voltage is applied between the third trimming electrode element and the seismic mass, and a fourth trimming voltage is applied between the fourth trimming electrode element and the seismic mass, wherein the first trimming voltage u 1 , the second trimming voltage u 2 , the third trimming voltage u 3 and the fourth trimming voltage u 4 are each set substantially with the following dependence of the resonance frequency manipulated variable ũ T , the quadrature manipulated variable ũ C and the resetting variable ũ S :
u 1 =√{square root over ( ũ T −ũ C +ũ S )}, u 2 =√{square root over ( ũ T +ũ C −ũ S )},

u 3 =√{square root over ( ũ T +ũ C +ũ S )}, u 4 =√{square root over ( ũ T −ũ C −ũ S )}.

3. The method as claimed in claim 1 , wherein the trimming electrode elements are each embodied and arranged in such a way that a capacitance C 1 , C 2 , C 3 and C 4 is formed between the first, second, third and fourth trimming electrode element and a respectively associated mass electrode element of the associated seismic mass, with the associated trimming voltage being applied between the trimming electrode element and the mass electrode element, as follows:

C
1

=

ɛ
0

⁢

A
1

+

r
1

⁢

t
1

⁢

q
1

g
1

-

s
1

⁢

q
2

,

C
2

=

ɛ
0

⁢

A
2

+

r
2

⁢

t
2

⁢

q
1

g
2

+

s
2

⁢

q
2

,

C
3

=

ɛ
0

⁢

A
3

-

r
3

⁢

t
3

⁢

q
1

g
3

-

s
3

⁢

q
2

and

C
4

=

ɛ
0

⁢

A
4

Assignees

• Egretzberger Markus
• Kugi Andreas
• Mair Florian
• Maurer Michael
• Manoli Yiannos
• Northemann Thomas
• Continental Teves Ag & Co Ohg
• Albert-Ludwigs-University Of Freiburg

Inventors

• Egretzberger Markus
• Kugi Andreas
• Mair Florian
• Maurer Michael
• Manoli Yiannos
• Northemann Thomas

Classifications

• G01C19/5712

  the devices involving a micromechanical structure · CPC title

• G01P3/14 Primary

  by exciting one or more mechanical resonance systems · CPC title

• G01C19/56 Primary

  Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces · CPC title

• G01C19/5726

  Signal processing · CPC title

• G01C19/5621

  the devices involving a micromechanical structure · CPC title