Transcript 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