Sensors 01

download Sensors 01

of 23

Transcript of Sensors 01

  • 7/28/2019 Sensors 01

    1/23

    technische universitt

    dortmund

    Arbeitsgebiet

    Mikrostrukturtechnik

    Sensor Technologies

    Prof. Dr.-Ing. Andreas Neyer

  • 7/28/2019 Sensors 01

    2/23

    ArbeitsgebietMikrostrukturtechnik

    A. Neyer, SENSORS, Lecture 01 Folie 2

    Sensor Technologies

    Sensor Technologies

    Introduction

  • 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)

  • 7/28/2019 Sensors 01

    4/23

    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

  • 7/28/2019 Sensors 01

    5/23

    ArbeitsgebietMikrostrukturtechnik

    A. Neyer, SENSORS, Lecture 01 Folie 5

    Service Robot in Space

  • 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

  • 7/28/2019 Sensors 01

    7/23

    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)

  • 7/28/2019 Sensors 01

    8/23

    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

  • 7/28/2019 Sensors 01

    9/23

    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

  • 7/28/2019 Sensors 01

    10/23

    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

    11/23

    ArbeitsgebietMikrostrukturtechnik

    A. Neyer, SENSORS, Lecture 01 Folie 11

    Sensor Technologies

    Generalities about sensors

    Sensor characteristicsLinearity

    Precision / Repeatability

    Sensitivity / Resolution

    Dynamic characteristics

  • 7/28/2019 Sensors 01

    12/23

    ArbeitsgebietMikrostrukturtechnik

    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

  • 7/28/2019 Sensors 01

    13/23

    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:

  • 7/28/2019 Sensors 01

    14/23

    ArbeitsgebietMikrostrukturtechnik

    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)

  • 7/28/2019 Sensors 01

    15/23

    ArbeitsgebietMikrostrukturtechnik

    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)

  • 7/28/2019 Sensors 01

    16/23

    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

  • 7/28/2019 Sensors 01

    17/23

    ArbeitsgebietMikrostrukturtechnik

    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

  • 7/28/2019 Sensors 01

    18/23

    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

  • 7/28/2019 Sensors 01

    19/23

    ArbeitsgebietMikrostrukturtechnik

    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

  • 7/28/2019 Sensors 01

    20/23

    ArbeitsgebietMikrostrukturtechnik

    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

  • 7/28/2019 Sensors 01

    21/23

    ArbeitsgebietMikrostrukturtechnik

    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

  • 7/28/2019 Sensors 01

    22/23

    ArbeitsgebietMikrostrukturtechnik

    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

  • 7/28/2019 Sensors 01

    23/23

    ArbeitsgebietMikrostrukturtechnik

    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