USO0RE41847E
(19) United States (12) Reissued Patent
(10) Patent Number: US RE41,847 E (45) Date of Reissued Patent: Oct. 19, 2010
Nakagaki et a]. (54)
(56)
SENSOR PROVIDED WITH ADJUSTING
References Cited
FUNCTION U.S. PATENT DOCUMENTS
(75) Inventors: Toshiya Nakagaki, Wakayama (JP); Toshiyuki Nozoe, Kyoto (JP); Takahiro Manabe, Osaka (JP)
12/235,884
(22)
PCT Filed:
Jul. 14, 1998
(86)
PCT No.:
PCT/JP98/03144
§ 371 (00)’ (2), (4) Date:
Apr. 8, 1999
(87)
DE GB JP JP
(52) (58)
11/1996 Shimada et a1.
5,848,383 A
* 12/1998
5,939,630 A
*
Yunus ...................... .. 702/104
8/1999 NoZoe et a1. 3/2001
Wolfet a1. ........... .. 324/207.12
3150013 A1 2218214 A 62-218813 5-45520
6/1983 11/1989 * *
9/1987 6/1993
OTHER PUBLICATIONS
Related US. Patent Documents
(51)
Lampe ............. .. 364/57104 Esmer et a1. ................ .. 33/356
FOREIGN PATENT DOCUMENTS
Supplementary European Search Report for EP 98 93 1086, dated Apr. 22, 2005.
Reissue of:
6,324,482
Issued:
Nov. 27, 2001
Appl. No.: Filed:
09/254,691 Apr. 8, 1999
* cited by examiner
Primary ExamineriJohn H Le (74) Attorney, Agent, or FirmiRatnerPrestia
Foreign Application Priority Data
Jul. 14, 1997 Jul. 22, 1997
* 10/1991 * 11/1992
5,574,211 A
PCT Pub. Date: Jan. 28, 1999
(30)
4/1991 Poelsler et a1.
6,198,275 B1 *
PCT Pub. No.: WO99/04226
(64) Patent No.:
6/1984 Baylor
5,008,843 A 5,062,065 A 5,161,311 A
(73) Assignee: Panasonic Corporation, Osaka (JP) (21) Appl. No.:
4,454,483 A
(JP) ........................................... .. 9-188082 (JP) ........................................... .. 9-195371
(57)
ABSTRACT
An object of the present invention is to provide an automatic compensation sensor that can eliminate an exclusive input
Int. Cl. G01C 19/00
terminal for the compensation mode signal. To achieve this object, the present invention comprises a sensor body (1), a
(2006.01)
US. Cl. ......................... .. 702/104; 331/11; 345/418 Field of Classi?cation Search .................. .. 702/85,
signal output terminal (5) for outputting signals from the sensor body (1), and a controller for compensating the out
702/91,99,104,107,130,133,134,136,
put signal from this signal output terminal (5).
702/183, 189, 190; 331/11; 345/418 See application ?le for complete search history.
11 Claims, 17 Drawing Sheets
1
3
Sensor body ___> Sign?“
Sign?‘ _
adder
output circult
2
Microcomputer and its
circuits
E
Signal
Output terminal
/
peripheral
4
t
\ 21 22
US. Patent
0a. 19, 2010
Sheet 1 0117
US RE41,847 E
FIG. 1 1
3
Sensorbodv ->
Signal adder
> Q
Sign?" . output circult
Signal output terminal
2
/
Microcomputer and its
peripheral
4
‘\
circuits \ \ 21
US. Patent
0a. 19, 2010
Sheet 2 0f 17
US RE41,847 E
FIG. 2
*
81
Check digital input terminal 22
S2
Presence of data
/-/ Yes
53
Illegal data No
Compensaticn mode
Normal operation mode
S6
US. Patent
0a. 19, 2010
Sheet 3 0f 17
US RE41,847 E
FIG. 3 7
r/ Diagnosis _
1
3
/ S
b d
ensor 0 y 2
r" _
> Signal adder
» output circult 4 K] Signal
output circuit
8 Diagnosis
output terminal 5
>Elf/Signal output 1
/
Microcomputer and its
peripheral circuits 21
' I ermma
US. Patent
0a. 19, 2010
Sheet 4 of 17
US RE41,847 E
FIG. 4 7
r,
> Diagnosis 1 r" Sensorbod
3 r’ .
y
> 2321::
> output circuit 4 f" Si nal 9
' output circuit
8
[5 Diagnosis output terminal 5
>Ur/Signal output
2
terminal
/_/
Microcomputer and its
peripheral
"\
circuits \ w 21 22
23
US. Patent
0a. 19, 2010
Sheet 5 of 17
US RE41,847 E
FIG. 5 9 r’
10
AC
T
separator ‘
1
3
4
Sensorbody —> Signal adder 2 r’
—>[{ circuit
Signal output terminai
Microcomputer and its
peripheral circuits
24
21
11
US. Patent
0a. 19, 2010
Sheet 7 0f 17
US RE41,847 E
FIG. 7
( Start > P
S1 0
1
‘'
\\ Temperature AID conversion
Output
815
compensation I‘) value from D/A
1
S16
Offset A/D "J Within
predetermined range No \
_
adjustment
819 Set in rewritable memory
/
H)
US. Patent
0a. 19, 2010
Sheet 8 of 17
FIG. 8
820
Temperature A/D conversion
S21
Read
compensation value S22
Output from WA converter
US RE41,847 E
US. Patent
0a. 19, 2010
Sheet 9 0f 17
US RE41,847 E
om
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US. Patent
0a. 19, 2010
US RE41,847 E
Sheet 11 0f 17
FIG. 11 One minute
Measure
S30
temperature T
l Measure
S31
error
Xi (T)
1 Calculate mean
valueX (T)
S32
US. Patent
0a. 19, 2010
Sheet 12 0f 17
US RE41,847 E
FIG. 12
Calculate Mean value X
Update compensation value F (T)
S33
S34
US. Patent
Oct. 19, 2010
Sheet 14 0f 17
US RE41,847 E
FIG. 14
.
Calculate zone
S35
displacement X (Rt)
Update compensation value F (T)
836
US. Patent
0a. 19, 2010
Sheet 16 0f 17
US RE41,847 E
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US. Patent
0a. 19, 2010
Sheet 17 of 17
US RE41,847 E
FIG. 17 1
3
f/
4
r’
Sensor body _.._> Signal adder 2 [J
r’
,
Signal °utPut circuit
5
—>|j/ Signai output terminal
Microcomputer and its
6
peripheral I\_ circuits
E?
"
\ \ 33
Compensation mode signal
82
input terminal
US RE41,847 E 1
2 sending compensation signals during manufacturing pro
SENSOR PROVIDED WITH ADJUSTING FUNCTION
cesses. This needs to be appropriately processed on comple tion of the automatic compensation sensor to prevent errone
Matter enclosed in heavy brackets [ ] appears in the original patent but forms no part of this reissue speci?ca tion; matter printed in italics indicates the additions made by reissue. This is a Reissue Application 0fU.S. Pat. No. 6,324,482, issued Nov. 27, 200]. This application is a US. National Phase application of PCT International application PCT/JP98/03l44.
ous compensation operation of the sensor. If compensation can be tested during assembly, it may be relatively easy to
modify the exclusive input terminal for the compensation mode signal. However, in case of angular velocity sensors, for example, correct output characteristics may not be
obtained during assembly, requiring the adjustment of a ?n ished product identical to those to be shipped. There are many such types of automatic compensation sensors. In this
FIELD OF THE INVENTION
case, modifying the exclusive input terminal for the compen
The present invention relates to the ?eld of automatic compensation sensors.
ing the terminal and case structure of the automatic compen sation sensor and thus increasing the cost.
sation mode signal becomes extremely dif?cult, complicat
BACKGROUND OF THE INVENTION
SUMMARY OF THE INVENTION
FIG. 17 shoWs the structure of a conventional automatic compensation sensor, in Which reference numeral 1 is a sen
An object of the present invention is to provide an auto matic compensation sensor Which enables the elimination of
sor body. Reference numeral 2 is a microcomputer including
an analog compensation signal output circuit, analog signal
20
input circuit, memory circuit, and its peripheral circuits. Components such as a temperature sensor When the purpose
of the automatic compensation sensor is to compensate for temperature are also included in reference numeral 2.
Hereafter, reference numeral 2 including peripheral circuits
an exclusive input terminal for the compensation mode sig nal. To achieve this object, the present invention comprises a
sensor body, a signal output terminal Which outputs the sig nal from the sensor body, and a controller for compensating 25
the output signal from the signal output terminal.
is called a microcomputer 2. Reference numeral 3 is a signal adder to Which the output of the sensor body 1 and the output of the microcomputer 2 are connected. Reference numeral 4
With the above con?guration, it is possible to realize an automatic compensation sensor Without requiring an exclu
is a signal output circuit comprising an ampli?er. Reference numeral 5 is a signal output terminal. The output signal of the signal adder 3 is connected to the analog input terminal
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an automatic compensation sensor in accordance With a ?rst exemplary embodiment of
sive input terminal for the compensation mode signal.
21 of the microcomputer 2. Reference numeral 6 is a com
the present invention.
pensation mode signal input terminal, and is connected to a
digital input terminal 22 of the microcomputer 2. During compensation, an external signal source is connected to this
35
compensation mode signal input terminal 6.
of the present invention.
Operation of the above automatic compensation sensor is described beloW. The microcomputer 2 has tWo modes: a compensation mode and a normal operation mode. The com
pensation mode is activated When a compensation signal is
FIG. 4 is a block diagram of an automatic compensation sensor in accordance With a third exemplary embodiment of 40
tion by high and loW logic levels. The compensation mode signal input terminal 6 is pulled up inside the automatic
of the present invention. 45
FIG. 7 is a How chart of control procedures in a compen 50
open, the microcomputer 2 is able to recognize the compen
sation mode by applying “loW” voltage to the compensation mode signal input terminal 6. Accordingly, the microcom puter 2 is capable of determining the compensation mode by checking the voltage level of the digital input terminal 22.
55
the present invention.
terminal 6 from being erroneously set to the compensation 60
input terminal for the compensation mode signal used for
FIG. 10 is a block diagram of an automatic compensation sensor in accordance With a seventh exemplary embodiment
of the present invention. FIG. 11 is a How chart for calculating a mean offset error
“loW” by noise, the possibility of erroneous setting to the compensation mode may be reduced by con?guring the This automatic compensation sensor requires an exclusive
operation mode of the automatic compensation sensor in accordance With the ?fth exemplary embodiment of the present invention. FIG. 9 is a block diagram of an automatic compensation sensor in accordance With a sixth exemplary embodiment of
it impossible to apply loW voltage after compensation is completed, to prevent the compensation mode signal input
compensation signal using serial communications.
sation setting mode of the automatic compensation sensor in accordance With the ?fth exemplary embodiment of the present invention. FIG. 8 is a How chart of control procedures in a normal
Here, it is necessary to take appropriate measures to make
mode. Furthermore, if there is a possibility that the compensa tion mode signal input terminal 6 may be accidentally set to
FIG. 6 is a block diagram of an automatic compensation sensor in accordance With a ?fth exemplary embodiment of
the present invention.
compensation sensor by a resistance. If the compensation
mode signal input terminal 6 is normally at “high” level When the compensation mode signal input terminal 6 is
the present invention. FIG. 5 is a block diagram of an automatic compensation sensor in accordance With a fourth exemplary embodiment
input from the compensation mode signal input terminal 6. In other cases, the automatic compensation sensor operates
in the normal operation mode. One example of the compensation signal is a determina
FIG. 2 is a How chart of the operation of the sensor. FIG. 3 is a block diagram of an automatic compensation sensor in accordance With a second exemplary embodiment
of the automatic compensation sensor in accordance With the
seventh exemplary embodiment of the present invention. 65
FIG. 12 is a How chart for updating a compensation value of the automatic compensation sensor in accordance With the
seventh exemplary embodiment of the present invention.
US RE41,847 E 3
4
FIG. 13 is a block diagram of an automatic compensation sensor in accordance With an eighth exemplary embodiment
The microcomputer 2 executes serial signal receiving pro cedures for receiving the above compensation signal. One example is explained next. The microcomputer 2 checks the value of the digital input
of the present invention. FIG. 14 is a How chart for updating of a compensation value of the automatic compensation sensor in accordance
terminal 22 every t1 seconds. Here, tl is a value satisfying tl
With the eighth exemplary embodiment of the present inven tion. FIG. 15 is a block diagram of an automatic compensation sensor in accordance With a ninth exemplary embodiment of
the present invention. FIG. 16 is a How chart for detecting abnormality of the automatic compensation sensor in accordance With the ninth
exemplary embodiment of the present invention.
incorrect, the microcomputer 2 judges that the data is illegal.
FIG. 17 is a block diagram of an automatic compensation sensor of the prior art.
To prevent erroneous compensation during normal opera tion after completing compensation, it is effective to make
DESCRIPTION OF THE PREFERRED EMBODIMENT
First Exemplary Embodiment
the microcomputer 2 sample the digital input terminal 22 20
only for a certain period after turning on the poWer. FIG. 2 is a How chart illustrating the above operation. The
A ?rst exemplary embodiment of the present invention is
microcomputer 2 checks the digital input terminal 22 during
explained With reference to FIGS. 1 and 2. FIG. 1 shoWs an
step S1. Then, the microcomputer 2 determines the presence of the compensation signal during step S2. If the compensa tion signal is properly received, the presence of illegal data is checked during step S3. If there is no illegal data, the micro
automatic compensation sensor in the ?rst exemplary embodiment of the present invention. In FIG. 1, reference numeral 1 is a sensor body, and reference numeral 2 is a
25
microcomputer including an analog compensation signal output circuit, analog signal input, circuit, and memory
computer 2 executes the compensation mode in step S4. For example, if the purpose of the sensor is to compensate for temperature, the operating temperature range of the auto
circuit, and its peripheral circuits. In addition, other compo nents such as a temperature sensor When the purpose of the
automatic compensation sensor is to compensate for tem perature are included in reference numeral 2. Hereafter the
30
compensating the output of the sensor body 1 is output to the signal adder 3, and this value is stored. Here, the output of the signal adder 3 is fed back to the analog input terminal 21
reference numeral 2 including peripheral circuits is referred to as a microcomputer 2. Reference numeral 3 is a signal
adder to Which the output of the sensor body 1 and the output of the microcomputer 2 are connected. Reference numeral 4 is a signal output circuit comprising an ampli?er With output resistance. Reference numeral 5 is a signal output terminal. The output signal of the signal adder 3 is connected to the
35
sensor body 1 has temperature hysteresis, the operating tem perature range is traced back and forth to determine the com 40
input terminal 22. During compensation, an external signal source for sending the compensation mode signal is con nected to the signal output terminal 5. The operation of this automatic compensation sensor is
explained next. During compensation, the external signal
45
ciently complicated in comparison With the signal Which the sensor is intrinsically capable of outputting. Since the signal 50
compensation signal Within a speci?ed time in step S5. If no compensation signal is received, or if an illegal signal is received during step S3, it returns to the normal operation mode during step S6. This enables the reduction of the prob ability of erroneous operation of the compensation mode in commercial versions of this product. In the normal operation mode, in case of the above temperature compensation, the current temperature is measured, and a compensation value corresponding to that temperature is read so as to compen sate for any output error of the sensor body due to tempera
of driving the output resistance included in the signal output circuit 4 as a load resistance. This enables the microcom
puter 2 to receive an external signal through the digital input terminal 22 by reading it at the output section of the signal output circuit 4. Here, the digital input terminal 22 of the
pensation level for that temperature by calculating a mean value for the compensation during temperature rise and tem perature decrease. This improves the compensation accu racy. The microcomputer 2 then determines the presence of a
source sends a predetermined compensation signal through the signal output terminal 5. This signal needs to be su?i output terminal 5 is originally an output terminal, its output impedance is relatively loW. The external signal source con nected to the signal output terminal 5 may need to be capable
of the microcomputer 2 to increase the accuracy of the com
pensation level by con?rming the compensation result. If the
analog input terminal 21 of the microcomputer 2, and the output of the signal output circuit 4 is connected to a digital
matic compensation sensor is traced in a constant tempera ture chamber, for example, to measure the output of the sen sor body 1 at each temperature. A value just suf?cient for
55
ture changes by outputting the compensation value to the signal adder. Second Exemplary Embodiment
microcomputer 2 can receive an external signal Without
FIG. 3 shoWs an automatic compensation sensor in a sec
being affected by any kind of signal output from the signal
In this exemplary embodiment, the compensation signal
ond exemplary embodiment of the present invention. In FIG. 3, the sensor body 1, microcomputer and its peripheral cir cuit 2, signal adder 3, signal output circuit 4, and signal
comprises the n numbers of 8-bit data With a start bit and
output terminal 5 have the same con?guration as those of the
output circuit 4.
60
stop bit. In other Words, the compensation signal comprises
automatic compensation sensor in the ?rst exemplary
n-byte data, Which is sent via asynchronous serial communi cations. The transmission speed is preferably made sloW as
embodiment. HoWever, the output resistance is not necessar
permissible by other restrictions such as start time, to avoid any in?uence of noise.
65
ily required in the signal output circuit 4. In addition, an output terminal of a diagnosis output circuit, described later, is connected to the digital input terminal 23 of the micro
