Robotics Chapter 1 - Introduction

1. RoboticsChapter 1 - Introduction Dr. Amit Goradia

2. Topics • Introduction – 2 hrs • Coordinate transformations – 6 hrs • Forward Kinematics - 6 hrs • Inverse Kinematics - 6 hrs • Velocity Kinematics - 2 hrs • Trajectory Planning - 6 hrs • Robot Dynamics (Introduction) - 2 hrs • Force Control (Introduction) - 1 hrs • Task Planning - 6 hrs

3. Introduction • Definition (Robot Institute of America): • A robot is a programmable multifunction manipulator designed to move material, parts, tools, or specialized devices through variable programmed motions for the performance of a variety of tasks. Puma 560 Robot used for inspection

4. Types of Robots • Stationary • Mobile – Ground • Wheeled • Tracks • Legs • Mobile – Underwater • Mobile – Aerial • Microgravity (Space) Honda ASIMO

5. Robot Types - Stationary Puma 560 Arm ABB Arm MSU Microbot

6. Mobile Sony’s QRIO MSU Micro Crawler MSU Mobile Manipulator Research Platform (R2-D2) Stanford’s Stanley (First winner of DARPA Grand Challenge)

7. Space Sojourner -First Mars Rover (1998) Canada Arm On International Space Station ISRO’s Chandrayaan -1 JPL’s Pioneer Space Probe

8. Robot – Mechanical Structure

9. Brief History • 1921 – Word robot derived from a Czech play • 1940s – Teleoperator developed at Oak Ridge national Labs • 1954 – George Devol, Programmed articular transfer device • 1956 – Joe Engelberg, Unimation (first robotics company) • 1961 – First robot installed on assembly line in GM • 1968 – Japan, Kawasaki makes robots • 1969 – GE makes first walking robot • 1974 – First Hydraulic drive robot, Cinciniti Milacron • 1978 – First Puma Robot (Programmable Universal Machine for Assembly)

10. Accuracy, Repeatability and Resolution • Accuracy: • A measure of how close a manipulator can come to a given point within its workspace • Repeatability: • A measure of how close a manipulator can return to a previously taught point • Resolution (Precision): • The smallest increment of motion that can be sensed (executed). It is a function of distance traveled and the number of bits of encoder accuracy. Accuracy Actual Desired Position B A Resolution

11. Robot Specifications • Joint Variable (joint): • Relative displacement between adjacent links. Can be revolute or prismatic. • End effector: • Gripper or tool used to perform the robots tasks. • Degree of freedom (DOF) • Number of joints (DOF > 6 implies redundant robot) • Configuration: • Determines the location of every point on the manipulator (not just the end effector). • Configuration Space • The set of all possible configurations • Workspace (work envelope): • Total volume spread out by the end effector as the manipulator executes all possible motions • Accuracy, Repeatability and Resolution • Speed and Acceleration (min and max) • Payload Capacity

12. Typical Robot Specifications • Hydraulic or Electric • Payload capacity • 50 – 100 Kgs (Hydraulic) • 1 – 25 Kgs (Electric) • Degrees of freedom: 4 to 7 based on application • Repeatablity • ± 1 mm – 1.5mm (Hydraulic) • ± 0.05mm – 0.01mm (Electric) • Cost • $80,000 - $200,000 (Hydraulic) • $40,000 – $100,000 (Electric)

13. Environment Sensors Planner World space Output Controller Drives Mechanical Structure Computer Configuration Sensor Robotic System Architecture • Components • Mechanical structure • Drives • Electric • Hydraulic • Pneumatic • Computing and Control • Sensors • Encoders • Force • Vision • many more • Communication • CAN, ethernet, Wireless, Serial link (RS232), USB, analog link, PROFIBus, GPIB, and many more

14. Common Robot Configurations • Joint types • Revolute • Prismatic • Revolute joints (R) • Compact • Increased dexterity – easier to maneuver around obstacles • Large kinematic and dynamic coupling between links • Larger error accumulation • Difficult control problem • Prismatic joints (P) • Increased accuracy • Higher payload • Difficult to integrate • Require more volume

15. Cartesian Configuration • PPP • First three joints are prismatic • Features • High resolution • High accuracy • High payload capacity • More volume needed for motion • Difficult to integrate with other machines • Uniform resolution Epson Cartesian Arm Reachable Workspace

16. Cylindrical Configuration • RPP • One revolute joint • Two linear joints • Joint coordinates map to cylindrical coordinates • r, θ, z • Non-uniform precision • Horizontal precision highest along inside edge of work envelope Denso Cylindrical arm Reachable Workspace

17. Spherical Configuration • RRP • Two revolute joints • One prismatic joint • Joint variables directly correspond to spherical coordinates • φ • θ • r Reachable Workspace

18. Articulated Configuration • RRR • Three revolute joints • Features • Light payload capacity • Lower accuracy • Easy to integrate with other manipulators

19. SCARA Configuration • Selective Compliant Articulated Robot for Assembly (SCARA) • RRP • Two revolute • One prismatic • Introduced in 1979 • Revolutionized manufacturing of small electronics Reachable Workspace

20. Effectors and Mobility Autonomous Flight Fish Robots Legged Motion Artificial Muscles Drives Sensors Vision Force / Haptic Communication Encoder Control Systems Behaviour control Networked control Active vibration control Hyper redundant robotic systems Task Planning Understanding the real world Failsafe planning to work in the real world Basic Research Issues

21. Robot Programming • Motion based • RCCL • RAPID • VAL++ • Task / Goal based • Behavior Language • PRS (Procedural Reasoning System) • Intermediate level • Combines aspects of low level motion based and high level task based • FRP (Functional Reactive Programming) • FROB (Functional Robotics)