Autonomous Intelligent Robotics Instructor: Shiqi Zhang - - PowerPoint PPT Presentation

Spring 2018 CIS 693, EEC 693, EEC 793:

Autonomous Intelligent Robotics

Instructor: Shiqi Zhang

http://eecs.csuohio.edu/~szhang/teaching/18spring/

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Ubuntu 14.04 + ROS Indigo

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ROS: Robot Operatins System

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Intelligent robot

External world Sensors Actuators Perception Cognition Action Sensing Modeling the world Action selection Planning Learning Multirobot coordination Motion Navigation Obstacle avoidance

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Example: TurtleBot

TurtleBot 'create' base Microsoft Kinect

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Software architecture

• Software architecture is

important for robotics because:

– Large code-bases – Integration of many different

(dynamic) set of devices

– Many different options for a single

component

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Controlling robots using code

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Straightforward approach

• Write a program to perform robot's 'cognitive' functions
• The program includes:

– Code to interface with the camera – Code to interface with the robot base – Code to understand the images and control the robot base

• Once implemented, the system works well and efficiently

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Straightforward approach

SOFTWARE HARDWARE

USB-USB USB-Serial

Specific camera driver Serial programming specific to 'Create'

This approach suffers from a problem. Any ideas? This approach suffers from a problem. Any ideas?

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An example problem...

• We later realized 'create' base is too slow (0.5 m/s).
• How easy it is to use a Segway base instead (up to 1.7 m/s)?

Could I have implemented my code differently to make this transition easier? Could I have implemented my code differently to make this transition easier?

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An example problem...

• We later realized 'create' base is too slow (0.5 m/s).
• How easy it is to use a Segway base instead (up to 1.7 m/s)?

Could I have implemented my code differently to make this transition easier? Could I have implemented my code differently to make this transition easier?

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Using robot middleware

Provide an abstraction layer and drivers between Provide an abstraction layer and drivers between computation and embodiment computation and embodiment

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Using robot middleware

SOFTWARE HARDWARE

USB-USB USB-Serial

middleware middleware

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The advantages

• Reuseability

– Reuse existing code and drivers written for other robots,

platforms and/or research projects

• Portability

– Easier to switch to another robotic platform

• Easier to expand functionality

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ROS (Robot Operating System)

• A very popular robot middleware

package

www.ros.com

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ROS (Robot Operating System)

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ROS (Robot Operating System)

• A very the most popular robot middleware package
• Peer-to-peer architecture among nodes over a

network

– A node is a process that performs some computation – Topics are named buses over which nodes exchange

messages

– Nodes communicate with each other by publishing

and subscribing to topics

– Services enable request-response communications

between nodes

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ROS nodes, messages, and topics

Node Node Node Node Node Node Service Topic Node Node Node publish subscribe response request

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How it works...

USB-USB USB-Serial

Ball following

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How it works...

USB-USB USB-Serial

vision camera 'create' control ROS master

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How it works...

USB-USB USB-Serial

vision camera 'create' control ROS master

I will receive images

• n topic "image" and

publish blobs on topic "blobs" I will receive blobs

• n topic "blobs"

and publish velocities on topic "cmd_vel" I will receive velocities on topic "cmd_vel" I will publish images on topic "image"

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How it works...

USB-USB USB-Serial

vision camera 'create' control ROS master

images

• n

'image' blobs on 'blobs' Velocities

• n

'cmd_vel' SET UP COMMUNICATIONS

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To summarize...

• Robot middleware improves software's reusability

and portability

• ROS is a very popular robot middleware

– Thousands of packages – More than 100 robot platforms

• Important ROS concepts

– Node – Topic – Message – Service

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Reading materials

• ROS tutorials

–

http://www.ros.org/wiki/ROS/Tutorials

• ROS paper:

–

'ROS: an open-source Robot Operating System', 2009

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Demo

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THE END