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Transcript of Sensors 01
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7/28/2019 Sensors 01
1/23
technische universitt
dortmund
Arbeitsgebiet
Mikrostrukturtechnik
Sensor Technologies
Prof. Dr.-Ing. Andreas Neyer
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7/28/2019 Sensors 01
2/23
ArbeitsgebietMikrostrukturtechnik
A. Neyer, SENSORS, Lecture 01 Folie 2
Sensor Technologies
Sensor Technologies
Introduction
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7/28/2019 Sensors 01
3/23
ArbeitsgebietMikrostrukturtechnik
A. Neyer, SENSORS, Lecture 01 Folie 3
Sensors in Robotics
Industry-Robots (fixed programming, view sensors)
Service-Robots (flexible, registration of environment by sensors)
Personal-Robots (universal and multimodal assistants)
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7/28/2019 Sensors 01
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ArbeitsgebietMikrostrukturtechnik
A. Neyer, SENSORS, Lecture 01 Folie 4
Service robot in a medical laboratory
2.1 Contact Sensors
RS232,
38400 bit/s
PA-10 arm
controllerPA-10Mitsubishi
Heavy Industries
stationary
PC
connected
to other
laboratory
equipment
and to a
database
control
PC with
Linux
and
software
for
mobile
robotand arm
TCP/IP
IEEE
802.11b,
11 Mbit/s
ARCNET
controller
C167
left and right hand drive
RS42
2,500000
bit/s
RS422,500000 bit/s
odom
etry
gyro
laser range finder
front and back
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7/28/2019 Sensors 01
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ArbeitsgebietMikrostrukturtechnik
A. Neyer, SENSORS, Lecture 01 Folie 5
Service Robot in Space
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7/28/2019 Sensors 01
6/23
ArbeitsgebietMikrostrukturtechnik
A. Neyer, SENSORS, Lecture 01 Folie 6
Terminology: Sensor - Transducer
Transducer:Elementary device capable of converting
a physical non-electrical input quantity (measurand)
into an electrical output quantity
Sensor:In general: Complex device consisting of transducer
and processing unit, e.g. for direct connection to PC
In this lecture:
Sensor = TransducerElementary physical device
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7/28/2019 Sensors 01
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ArbeitsgebietMikrostrukturtechnik
A. Neyer, SENSORS, Lecture 01
Coordinate Systems of Robots
Folie 7
1. Internal Sensorsdetermine by internal measurements
the actual coordinate system of the robot
Z
Y
Z X
Polar Cylindrical Cartesian Arm and elbow
(resolute)
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ArbeitsgebietMikrostrukturtechnik
A. Neyer, SENSORS, Lecture 01 Folie 8
Classification of Sensors for Robots
2. External Sensorsdetermine by externalmeasurements
e.g. the position of the robot relative to the
environment
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ArbeitsgebietMikrostrukturtechnik
A. Neyer, SENSORS, Lecture 01 Folie 9
Classification of Sensors for Robots
1. Internal
1.1 Position
1.1.1 Angular Position1.1.2 Linear Position
1.2 Angular Velocity
1.3 Acceleration
2. External
2.1 Contact Sensors
2.1.1 Tactile Sensors2.1.2 Force Sensors
2.1.3 Torque Sensors
2.2 Noncontact Sensors
2.2.1 Proximity2.2.2 Distance
2.2.3 Velocity
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7/28/2019 Sensors 01
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ArbeitsgebietMikrostrukturtechnik
A. Neyer, SENSORS, Lecture 01 Folie 10
Literature
S.R.Ruocco
Robot sensors and transducersOpen University Press, Milton Keynes, England,1987
H.R. EverettSensors for moblile robotsA.K.Peters, Natick, MA, 1995
J.Borenstein, H.R.Everett, L.FengWhere am I?Sensors and Methods for Mobile Robot Positionzum Download unter:http://www-personal.engin.umich.edu/~johannb/my_book.htm
Skript: Sensor Technologies
Download: www.mikrostrukturtechnik.deLehre Sensors
Username: mstsensorsPassword:Feldstaerke
http://www-personal.engin.umich.edu/~johannb/my_book.htmhttp://www-personal.engin.umich.edu/~johannb/my_book.htmhttp://www-personal.engin.umich.edu/~johannb/my_book.htmhttp://www-personal.engin.umich.edu/~johannb/my_book.htm -
7/28/2019 Sensors 01
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ArbeitsgebietMikrostrukturtechnik
A. Neyer, SENSORS, Lecture 01 Folie 11
Sensor Technologies
Generalities about sensors
Sensor characteristicsLinearity
Precision / Repeatability
Sensitivity / Resolution
Dynamic characteristics
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A. Neyer, SENSORS, Lecture 01 Folie 12
Generalities
Sensor qualification according to output characteristics
Absolute sensor:
Electrical ouput signal relates to input quantity with no ambiguity
Incremental sensor:
Counting device with no absolute reference value
Analogue sensor:
Output signal is continiuous and proportional to the physical
input quantity
Digital sensor:
At continuous input quantities the output signal can take only
discrete values
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7/28/2019 Sensors 01
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ArbeitsgebietMikrostrukturtechnik
A. Neyer, SENSORS, Lecture 01 Folie 13
General Considerations
on Sensor Transfer Characterstics
Sensor Transfer Characteristics:Relation between measurand and electrical output signal
Example:
Relation between linear position (measurand) and voltage (electrical
signal)at a potentiometer
x xmax
Vs
V0
1
2 3Physical construction
xmax
Schematic representation
1
2
3
x
VsVo
1 2
1
3
Potentiometer Transfer Characteristic:
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A. Neyer, SENSORS, Lecture 01 Folie 14
Ideal / real characteristics
Position x
VoltageVs
V0
xmax
x xmaxVs
V0
Typical items of sensor characteristics are:
- Linearity- Precision / Repeatability
- Sensitivity
- Resolution
- Dynamic characteristics (time response)
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A. Neyer, SENSORS, Lecture 01 Folie 15
Sensor Linearity
FSO: Full Scale Output
a) Linear characteristic with output saturation
b) Linear characteristic with +/- deviations in % of FSO
Linearity error
+8.6% -3.4% FSO
25
50
75
100
25 50 75 100
Output
(%FSO)
Measurand (% range)
a)b)
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ArbeitsgebietMikrostrukturtechnik
A. Neyer, SENSORS, Lecture 01 Folie 16
Linearity: Terminal line
Straight line between the 0% and 100% points of the full range
Output(%FSO)
Measurand (% range)
100
100
Terminal Line
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A. Neyer, SENSORS, Lecture 01 Folie 17
Linearity: End-point line
End-point line:
Straight line between the end pointsof the calibration curve
Output
(%FSO)
Measurand (% range)
100
100
Calibration curve
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ArbeitsgebietMikrostrukturtechnik
A. Neyer, SENSORS, Lecture 01 Folie 18
Linearity: Best straight line
Best straight line:
Line midway between the two parallel straight linesclosest together and envelope all output values
Output
(%FSO)
Measurand (% range)
100
100
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A. Neyer, SENSORS, Lecture 01 Folie 19
Precision
Precision:
Tolerance (in % of FSO) within which a measurement can be repeated
Output
(%FSO)
Measurand (% range)
100
100
Precision within
6.6% FSO
Run 1
Run 2
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A. Neyer, SENSORS, Lecture 01 Folie 20
Hysteresis
Hysteresis:
Maximum difference in ouput values (in % of FSO) obtained byreversing the direction of measurement (between 0% and 100%)
Output
(%FSO)
Measurand (% range)
100
100
Hysteresis
15% FSO
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A. Neyer, SENSORS, Lecture 01 Folie 21
Sensor Sensitivity /
Resolution
Sensor sensitivity:
Relation between variation of electrical output signal and correspondingvariation of physical input quantity
Sensor resolution:
Maximum change of measurand ( in % of range) without variation of sensor
output signal
(resolution of wirewound
potentiometer)
Output
(%FSO)
Measurand (% range)
100
100
Resolution
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A. Neyer, SENSORS, Lecture 01
Dynamic Charactersistics
Dynamic characteristics:
Response of the device to variations of the measurand with respect to time
- Frequency response:
Electrical output response
at sinusoid measurand varation for a certain frequency range
Percentage
amplitude
ratio
Measurand Frequency (Hz)
100
100
Band Passcharacteristics
Low Pass
characteristics
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A. Neyer, SENSORS, Lecture 01 Folie 23
Dynamic Charactersistics
- Step response:
Electrical output response at step change of input measurand
Amplitude
(%F
SO)
Storage time
100
Time
Input
90
Output
Delay time
Fall timeRise time
10