Real Robots Don’t Drive Straight - random 2 person breakout - 10 minutes

• What was the “Real Robots Don’t Drive Straight” about?
• What is/or are your key takeaways What surprised you?
• In breakout group - please nominate who will report out

How do Robots Perceive? Sensors

• What is a sensor? Is a sensor an input or output device?
• What happens to the sensing information
• How is it stored and detected and acted upon?

Types of Sensors

• Is a sensor an input or output device?
• Proprioception
• Is a keyboard a sensor?
• Is a joystick a sensor?
• Is a map a sensor?
• Active Vs. Passive
• Sensor Fusion

Lidar

• What is a Lidar
• What does it look like and how does it work?
• “Time of travel” detector
• What does the data look like?
  • Look here fore the message definition
  • roslaunch turtlebot3_gazebo turtlebot3_stage_1.launch
  • roslaunch turtlebot3_gazebo turtlebot3_gazebo_rviz.launch
  • rostopic echo --noarr -c /scan

Subtleties

• What do the directions mean?
• Are the directions absolute or relative?
• What if the robot is not pointing to where you think?
• Do they go clockwise or counterclockwise?
• Lets look at the data!
• It’s not clean! (This is typical for all sensors)
• It is not accurate!
• It’s sometimes wildly inaccurate
• It is constantly flooding in

Breakout (15 Minutes)

• Documentation for LaserScan Data
• Given
  1. angle_min = 0 # exactly forward
  2. angle_max = 359
  3. range_min = 0.12
  4. range_max = 3.5
• With your teammates write a few lines of python
• Set the variable wall_ahead to true or false

Motor (encoder)

• How it works
• Key characteristics or features
• What data it provides

Camera

• How it works
• Key Characteristics or features
• What Data it provides

Depth Camera

• How it works
• Key Characteristics or features
• What data it provides

Sonar

• How it works
• Key Characteristics or features
• What data it provides

Bump sensors

• How it works
• Key Characteristics or features
• What data it provides

IMU - Inertial Measurement Unit

• See Accelerometer, Gyro, IMU buying guide
• Acceleration: dynamic and static (as in gravity)
• Gyro: Angular velocity - how fast spinning around an acciss
• Can have them independently or combined into an IMU

GPS

• How it works
• Key Characteristics or features
• What data it provides

Thank you. Questions?  (random Image from picsum.photos)