Download Robotics

Intro to Robotics
EPGY Middle School Programming
Adam Leeper
What is a robot?
What is a robot?
What is a robot?
What is a robot?
What is a robot?
• Can sense the environment.
• Can make independent decisions.
• Can complete a task automatically.
Robot vs. Humans
• Pros:
– Robots can be arbitrarily fast, strong, or large.
– Robots can record vast amounts of data.
– Robots can run in dangerous environments.
• Cons:
– Robots are stupid and inflexible.
– Robots are really bad at dexterous manipulation.
– Robots are dangerous.
What senses do robots have?
• “Vision”
– Cameras
– IR range sensors
• “Hearing”
– Microphones
• “Touch”
– Bump sensors
– Capacitive and resistive sensors
What senses do robots have?
• “Other”
– Ultrasonic
– Radio/GPS
• Smell/Taste
– Maybe smoke detectors, but not commonly used.
Ultrasonic Sensor
• Uses high-frequency sound we can’t hear.
• Sound travels at 343 m/s in air.
• Can measure distance by measuring time
between a ping sent and received.
Touch Sensor
• Simplest is a contact switch.
• An electrical path is completed when pressed.
Power
Switch
Sensor output
Resistor
Ground
Light Sensor
• Many types.
• Similar to a touch sensor, a simple light sensor
has an electrical semiconductor component
that changes resistance when exposed to
light.
Sound Sensor
• It’s a microphone!
• Sound waves are converted to electrical
signals.
How do robots make decisions?
•
•
•
•
Individual sensors.
Sensor fusion.
Statistical methods.
Math formulas from a variety of science areas.
– http://www.youtube.com/user/WillowGaragevideo#p/u/30/VWxAk7Yeifs
Open-loop vs. Closed-loop
• This is the field of Controls.
• Open-loop
– Simple, but can have large errors.
• Closed-loop
– Requires sensors, but can correct for errors.
Temperature Controller
Desired
temperature
Controller
Actuator(Heater)
Sensor (thermometer)
Actual
temperature
Cool Robot Videos
• http://www.youtube.com/user/WillowGarage
video#p/u/2/HMx1xW2E4Gg
• http://www.youtube.com/user/WillowGarage
video#p/u/31/0WtGgpuS3qE
How do robots move?
• Motors and wheels
• Legs
http://www.youtube.com/watch?v=W1czBcnX1Ww
Drive Train
• Direct Drive
– Efficient, no backlash
– Low torque
• Gear Transmission
– High torque
– Friction, noise, and backlash
• Belt/Cable Drive
– Placement, performance
– Complex
The NXT motor
Choosing wheels
• Large wheels
– High top speed, good clearance,
– Low torque (acceleration)
• Small wheels
– High torque, perhaps better stability
– Lower top speed