Sensor Systems

1
Sensor Systems
2
Overview

• Sensor Transducer
• conversion of some form of energy into electrical
  energy
• Passive/ active sensor
• Active sensing
• Sensor modality
• type of energy measured

3
Sensing Model
4
Logical Sensors

• module
• signal processing
• software processing
• provides percept
• Logical equivalence

5
Behavioural Sensor Fusion

• Physically Redundant
• Logically Redundant
• overcome false positives and negatives
• Complementary
• each sensor does not provide complete view
• Coordinated
• series of sensors for cueing

6
Sensor Fission, Fusion and Fashion
7
Sensor Suites Reference Frames

• Proprioception
• relative to internal frame of reference
• Exteroception
• relative to robot frame of reference
• Exproprioception
• relative to external frame of reference

8
Sensor Attributes

• Field of view
• Accuracy-repeatability
• Responsiveness
• Power consumption
• Hardware reliability
• Size
• Computational Complexity
• Interpretation reliability

9
Sensor Suite Attributes

• Simplicity
• Modularity
• Redundancy (Physical Logical)
• Fault tolerance

10
Proprioceptive Sensors

• Encoders
• slip between wheel and surface
• Inertial Navigation Systems
• accelerometers measure acceleration
• integrate readings to get velocity and position
• Not suitable for jerky, bumping motion

11
Exproprioceptive sensors

• Global Positioning System(GPS)
• selective availability reduces accuracy
• position averaging
• differential GPS
• Radio triangulation

12
Proximity Sensors

• Sonar/ ultrasonics
• time of flight
• Infrared
• Contact Sensors

13
Computer Vision

• detailed in machine vision paper
• see chapter 6 AI robotics for details