Actuators and sensors. Part 1

OUTLINE

Motivation, why robots need sensors?
Difference between actuators and sensors
Robotic sensor classification
Sensor

Sensors in Robotics are primarily used for two different purposes:
1. Give

Examples:
DC motors
Servo motors
Stepper motors

Examples:
Temperature sensors
Humidity sensors
Light level sensors

Any kind of device that converts one kind of energy into

COMMON COMPLETE ROBOT SYSTEM

Take in a physical property through the sensor;
Converting

CLASSIFICATION

Robot sensors can be classified into two groups:
Internal sensors and

EXTERNAL SENSORS

External sensors: Obtain the information in the surrounding environment.
–

Evaluation Criteria for Sensors
1. Sensitivity - how sensitive is the sensor
-

DEVICE ERROR

Absolute Error (EA):
EA = measured value – true value
EA =

TOLERANCE (LIMITING ERROR)

For certain devices (components) we use Tolerance instead of

ACCURACY & INACCURACY

Definition: A measure of how close the output of

Example: X = 20 °C, Y = 21.3 °C , find

ANALOG SENSOR: POTENTIOMETER

Analog sensor for measuring the rotational position
Potentiometer = varying

SENSOR RESPONSE CURVE FOR POTENTIOMETER

Used to define different kind of properties

RANGE (FULL SCALE)

The difference between the minimum angle and the maximum

NONLINEARITY ERROR

SENSITIVITY

The amount of change in the output -> results from a