Gradient determination for measuring rotational speeds

Patent metadata

Field	Value
Publication number	US-11397191-B2
Application number	US-201816769537-A
Country	US
Kind code	B2
Filing date	Nov 7, 2018
Priority date	Dec 5, 2017
Publication date	Jul 26, 2022
Grant date	Jul 26, 2022

Abstract

An assembly has a rotating element, a sensor, and an evaluation unit; wherein the element has a number a of markings; wherein the markings pass through a region detected by the sensor in cycles when the element rotates; wherein the sensor is configured to send a signal to the evaluation unit; and wherein the evaluation unit is configured to assign a time ti for when each signal is sent, wherein the evaluation unit is configured to calculate a function m(t) over time t as a measure for a gradient of the rotational rate of the element.

First claim

The invention claimed is:

1. An assembly comprising:
a rotating element;
a sensor; and
an evaluation unit;
wherein the element has a number a of markings;
wherein the markings pass through a region detected by the sensor in cycles when the element rotates;
wherein the sensor is configured to send a signal to the evaluation unit; and
wherein the evaluation unit is configured to:
assign a time t i to when each signal is sent, where i∈{0, 1, . . . } and t i <t i+1 for all i∈{0, 1, . . . }, and
calculate a function n(t) over time t as a measure for a rotational rate of the element, where

n
⁡

(

t
i

)

=

1

a
*

(

t
i

-

t

i
-
1

)

for all i∈{1, 2, . . . };
calculate a function m(t) over time t as a measure for a gradient of the rotational rate of the element, where

m
⁡

(

t
j

)

=

n
⁡

(

t
j

)

-

n
⁡

(

t
k

)

t
j

-

t
k

for at least one j∈{1, 2, . . . }, wherein k∈{0, 1, . . . } is selected such that: t k ≤t j −T<t k+1 , when Tis a constant.

2. The assembly according to claim 1 , wherein

m
⁡

(

t

j
′

)

=

n
⁡

(

t

j
′

)

-

n
min

t

j
′

-

t
k

for at least one j′∈{1, 2, . . . }; and
wherein n(t k′ )<n min , and k′∈{0, 1, . . . } is selected such that: t k′ ≤t j′ −T<t k′+1 .

3. The assembly according to claim 1 , wherein
m ( t ′)= m ( t j )

for at least one time t′, where t j <t′<t 1+1 .

4. A method of measuring a rotational rate of a rotating element, the method comprising:
monitoring, by a sensor, markings on the rotating element that pass through a region monitored by the sensor in cycles when the rotating element rotates, wherein the element has a number a markings;
sending, by the sensor, signals to the evaluation unit, wherein each signal is assigned a time t i for when it was sent, where i∈{0, 1, . . . } and t i <t i+1 for all i∈{0, 1, . . . };
calculating, by the evaluation unit, a function n(t) over time t as a measure for a rotational rate of the element, where

n
⁡

(

t
i

)

=

1

a
*

(

t
i

-

t

i
-
1

)

for all i∈{1, 2, . . . }; and
calculating a function m(t) over time t as a measure for a gradient of the rotational rate of the element, where

m
⁡

(

t
j

)

=

n
⁡

(

t
j

)

-

n
⁡

(

t
k

)

t
j

-

t
k

for at least one j∈{1, 2, . . . }, wherein k∈{0, 1, . . . } is selected such that: t k <t j −T<t k+1 , when T is a constant.

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Wendzel Andreas
• Dreibholz Ralf

Classifications

• G01P3/44 Primary

  for measuring angular speed (G01P3/56 takes precedence) · CPC title

• G01P3/489

  Digital circuits therefor · CPC title

• G01P15/165 Primary

  for measuring angular accelerations · CPC title

• G01P3/36

  Devices characterised by the use of optical means, e.g. using infrared, visible, or ultraviolet light (G01P3/68 takes precedence; gyrometers using the Sagnac effect, i.e. rotation-induced shifts between counter-rotating electromagnetic beams G01C19/64) · CPC title