Introduction To Al Robotics PDF

1 Course Objectives Know what it takes to make a robust autonomous robot work: – Sense/Think/Act Understand the important, approaches, research issues and challenges...

1 Course Objectives Know what it takes to make a robust autonomous robot work: – Sense/Think/Act Understand the important, approaches, research issues and challenges in autonomous robotics. Know how to program an autonomous robot. Introduction to AI Robotics (MIT Press) Chapter 1 1  1 What Can Robots Be Used For? Manufacturing 3 Ds – Dirty – Dull – Dangerous Space – Satellites, probes, planetary landers, rovers Military Agriculture Construction Entertainment Consumer? Introduction to AI Robotics (MIT Press) Chapter 1 2  1 History of Intelligent Robotics 1940s – First remote manipulators for hazardous substances 1950s – Industrial manipulators: “reprogrammable and multi-functional mechanism designed to move materials, parts, tools…” – Closed loop control Introduction to AI Robotics (MIT Press) Chapter 1 3  1 History Continued 1955 – term “AI” coined 1960s manufacturing robots – Automatic guided vehicles (AGVs) – Precision, repeatability – Emphasis on mechanical aspects 1970s – Planetary landers – Machine vision research expands 1980s – Black factory – First intelligent autonomous robots: Shakey, Stanford Cart, etc Introduction to AI Robotics (MIT Press) Chapter 1 4  1 History Continued 1990s – Symbolic AI/Robotics stalls – Reactive/Behavior-based robotics emerges 2000s – ? Introduction to AI Robotics (MIT Press) Chapter 1 5  1 Intelligent Robot Mechanical creature which can function autonomously – Mechanical= built, constructed – Creature= think of it as an entity with its own motivation, decision making processes – Function autonomously= can sense, act, maybe even reason; doesn’t just do the same thing over and over like automation Introduction to AI Robotics (MIT Press) Chapter 1 6  1 “Intelligent” Robotics Basic robot primitives : Sense/Think/Act Three paradigms (architectures): - Hierarchical (Deliberative): Sense ->Plan ->Act ; - Reactive: Sense -> Act; - Hybrid (Deliberative/Reactive): Plan -> Sense -> Act Introduction to AI Robotics (MIT Press) Chapter 1 7  1 Ways of Controlling a Robot “RC-ing” – you control the robot – you can view the robot and it’s relationship to the environment – ex. radio controlled cars, bomb robots – operator isn’t removed from scene, not very safe teleoperation – you control the robot – you can only view the environment through the robot’s eyes – don’t have to figure out AI semi- or full autonomy – you might control the robot sometimes – you can only view the environment through the robot’s eyes – ex. Sojouner with different modes – human doesn’t have to do everything Introduction to AI Robotics (MIT Press) Chapter 1 8  1 Teleoperation Human controls robot remotely – Hazardous materials – Search and rescue – Some planetary rovers Considerations – Feedback (video, tactile, smell?) – User interfaces (cognitive fatigue, nausea) – Time/distance Introduction to AI Robotics (MIT Press) Chapter 1 9  Components of a Telesystem 1 (after Uttal 89) Local – display – Local control device Remote Communication Remote Local Communi- Sensor – sensor Display cation – mobility – effector Mobility – power Control Effector Power Introduction to AI Robotics (MIT Press) Chapter 1 10  1 Example Remote Local Introduction to AI Robotics (MIT Press) Chapter 1 11  1 Typical Run Introduction to AI Robotics (MIT Press) Chapter 1 12  1 Problems that You Saw no feedback, couldn’t really tell that the robot was stuck but finally got free – robot doesn’t have “proprioception” or internal sensing to tell you what the flippers were doing. No crunching noises, no pose widget to show the flippers no localization, mapping-> no idea how far traveled partial solution: better instrumentation (but can’t do dead reckoning well) – operator doesn’t have an external viewpoint to show itself relative to the environment solution: two robots, one to spot the other communications dropout, even though ~3 meters away lighting conditions went from dark to very bright – hard for computer vision or human to adjust Introduction to AI Robotics (MIT Press) Chapter 1 13  1 DarkStar+7 seconds=DarkSpot 7 second communications lag (satellite relay) “interruption” lag on part of operator Introduction to AI Robotics (MIT Press) Chapter 1 14  Predator: 1 ~7:1 human to robot ration Leo’s unofficial Predator page 4 people to control it (52-56 weeks of training) – one for flying – two for instruments – one for landing/takeoff plus maintenance, sensor processing and routing lack of self-awareness– in Kosovo, come along side in helicopter and shoot down Introduction to AI Robotics (MIT Press) Chapter 1 15  1 Teleop Problems cognitive fatigue communications dropout communications bandwidth communications lag too many people to run one robot Introduction to AI Robotics (MIT Press) Chapter 1 16  1 Telesystems Best Suited For: the tasks are unstructured and not repetitive the task workspace cannot be engineered to permit the use of industrial manipulators key portions of the task require dexterous manipulation, especially hand-eye coordination, but not continuously key portions of the task require object recognition or situational awareness the needs of the display technology do not exceed the limitations of the communication link (bandwidth, time delays) the availability of trained personnel is not an issue Introduction to AI Robotics (MIT Press) Chapter 1 17  1 Teleop Solutions Telepresence – improves human control, reduces simulator sickness and cognitive fatigue by providing sensory feedback to the point that teleoperator feels they are “present” in robot’s environment Semi-autonomous – Supervisory Control human is involved, but routine or “safe” portions of the task are handled autonomously by the robot Shared Control – human initiates action, interacts with remote by adding perceptual inputs or feedback, and interrupts execution as needed Traded Control – human initiates action, does not interact – Mixed Initiative (Guarded Control) robot doesn’t let the operator injure the robot (without override) “whoever figures it out first” Introduction to AI Robotics (MIT Press) Chapter 1 18  1 Collaborative Teleoperation 1 3 mpg: June 2, 2000 SRDR Miami Beach: view from Inuktun as it falls mpg: June 2, 2000 SRDR Miami Beach: view from Inuktun from hoisted position Urban is stuck, Inuktun can’t help from 2 current perspective 1. Driven off 3rd floor 2. Hoisted to 2nd floor by tether 3. Has better view, changing configuration & rocking extend view still: June 2, 2000 SRDR Miami Beach Introduction to AI Robotics (MIT Press) Chapter 1 19  1 2000 AAAI Mobile Robot 2 robots helping each other reduced collision errors, sped up time navigating confined space, righting Introduction to AI Robotics (MIT Press) Chapter 1 20  Example: 1 Mixed-Initiative & Collab. Teleop 9/2000 DARPA Tactical Mobile Robots demonstration Robot used an intelligent assistant agent to look for signs of snipers hiding in urban rubble – motion – skin color – difference in color – thermal (IR camera) Human navigated mother robot using viewpoint of 2nd robot (not in picture) Once deposited the human moved the daughter robot, and either saw a sniper or was alerted by the agent Introduction to AI Robotics (MIT Press) Chapter 1 21  1 AI provides the “other stuff” knowledge representation understanding natural langugage learning planning and problem solving inference search vision Introduction to AI Robotics (MIT Press) Chapter 1 22  1 Summary Teleoperation arose as an intermediate solution to autonomy, but it has a number of problems:cognitive fatigue, high comms bandwidth, short delays, and many:one human to robot ratios. Telepresence tries to reduce cognitive fatigue through enhanced immersive environments Semi-autonomy tries to reduce fatigue, bandwidth by delegating portions of the task to robot Introduction to AI Robotics (MIT Press) Chapter 1 23  2 The Hierarchical Paradigm Describe the Hierarchical Paradigm in terms of the 3 robot primitives and its organization of sensing Organization -SPA Name and evaluate one representative Hierarchical architecture in -global terms of: support for modularity, niche targetability, ease of Strips portability to other domains, robustness -Shakey Rep. Arch. Solve a simple navigation problem using STRIPS (hint: work -evaluation through Sec. 2.2.2) -NHC -RCA Summary Understand precondition, closed world assumption, open world, frame problem List two advantages and disadvantages of the Hierarchical Paradigm Introduction to AI Robotics (MIT Press) Chapter 2: The Hierarchical Paradigm 1  2 Organization SENSE PLAN ACT Organization -SPA -global Strips -Shakey Rep. Arch. -evaluation -NHC World model: -RCA 1. A priori rep Summary 2. Sensed info 3. Cognitive Introduction to AI Robotics (MIT Press) Chapter 2: The Hierarchical Paradigm 2  2 Shakey First AI robot Organization -SPA Built by SRI -global (Stanford Research Strips -Shakey Institute) for DARPA Rep. Arch. 1967-9 -evaluation -NHC -RCA Summary Used Strips as main algorithm for controlling what to do Introduction to AI Robotics (MIT Press) Chapter 2: The Hierarchical Paradigm 3  2 Strips: Means-ends analysis “Go to Stanford AI Lab” Organization -SPA INITIAL STATE: Tampa, Florida (0,0) -global Strips GOAL STATE: Stanford, California (1000,200) -Shakey Rep. Arch. -evaluation Difference: 1020 miles -NHC -RCA Summary Introduction to AI Robotics (MIT Press) Chapter 2: The Hierarchical Paradigm 4  2 Difference Table Distance mode of transportation (difference) (OPERATOR) Organization d>=200 miles FLY -SPA -global 100