Presentation Transcript
Sensors: Sensors
Definition: Definition Sensor: A device which provides information about the physical world.
Transducers: Transducers Convert of energy from one form to another.
e.g. microphone and speakers convert between acoustic and electrical energy.
Many transducers are bidirectional.
Some sensors are transducers; almost all involve transduction.
What can be sensed?: What can be sensed? Direct Transduction: e.g., electric and magnetic fields, mechanical strain, temperature, electromagnetic energy...
Derived quantities: e.g. distance, human presence, heading, air flow, molecular concentrations, air pressure, color...
Common Animal Sensors: Common Animal Sensors
Unusual Animal Sensors: Unusual Animal Sensors Magnetoreceptor: Sensing of earth’s magnetic field. Seen in newts, birds, rats and maybe humans.
Electric field sensing: Seen in a variety of fish.
Cerci: Cockroach airflow sensors
Body as eye: Brittlestar covered with optically perfect lenses
Biological Rotation Sensor: Biological Rotation Sensor semicircular canals detect angular acceleration
3 canals: one per plane
inertia of fluid causes deflection of sensory element
Robot design as creature design: Robot design as creature design Animal sensory systems adapted to functional needs and environment.
Robots can use non-biological sensors which suit them to their ‘ecosystems’
e.g., neutron-sniffing robodog, UAV with weather radar, etc.
Sensors for dead reckoning: Sensors for dead reckoning
Typical sensor: optical encoder
One type found in standard computer mouse
Quadrature encoding
Sensors for orientation/heading: Sensors for orientation/heading Use: orientation/heading
Options: gyroscope, geomagnetic sensors
Issues: gyro drift, B-field distortion
Sensors for obstacle detection: Sensors for obstacle detection e.g., where are walls?
Options: ultrasonic TOF, lateral-effect photodiode (PSD)
Sensors for detecting humans: Sensors for detecting humans Options: computer vision, pyroelectric sensor
pyroelectric sensors detect far-IR radiation
can also detect heat, fire
standard alarm sensor (cheap)