Chapter 7: Agents and Robots

1. Chapter 7: Agents and Robots

2. Objectives At the end of the chapter, you should be able to: • Describe the capabilities required of an intelligence agent. 2. Give three applications of software agents. 3. Describe and compare manufacturing robots and autonomous mobile robots, stating what each may used for. 4. Explain why humanoid robots are developed, and how this work contrasts with traditional work in AI. Ch06A / 2

3. Topics • Introduction • Software Agents • Robots Ch06A / 3

4. Introduction • What is Intelligent Agent? • Something that act independently, with well-defined goals, usually carrying out tasks on behalf of a human user. • It should be able to Adapt what it is doing based on information it receives from its environment or from other agents. • A group of them may operate in the same environment, communicating with each other, sending information or requests. Human “agents” may also included Ch07A / 4

5. Introduction • Example 1: An agent whose task was to do shopping. Initial goal is to buy some carrots. • The agent must be able: • Act independently • Communicate with each other agents (such as the shop assistant • Modify what it is doing in response to what it sees and hears. • If it sees some really nice parsnips, then the goal of getting carrots might be revised. • If it drops the carrots/parsnips in a puddle on the way home then it will have to adapt its plan and go back and get some more. Ch07A / 5

6. Introduction • Example 2: Vacuum Cleaner World • Percepts: location and status, e.g., [A,Dirty] • Percept sequence • Everything the agent has observed so far • Actions: Left, Right, Suck, NoOp • Mapping percept to action Ch07A / 6

7. Introduction Intelligent Agent can be divided into • Software Agents. • Software which operate within the confines of the computer (or computer network) • Physical Agents. • Agent which operate in the physical world and can percieve and manipulate objects in that world. For example, robot • The design of an intelligent agents may require techniques include • Planning techniques may be used to enable it can plan what to do • Natural language techniques used to communicate with the user • Expert system methods used to solved specialized problems • Knowledge representation techniques used to represent the required knowledge. • Vision techniques used to make sense of the physical environment • Learning techniques used to make the agent can adapt and improve its behaviour. • Recent development – it can acts over an extended period of time, in environment which may be constantly changing, and where new information received may mean change priorities. Ch07A / 7

8. Software Agents Software Agents • An independent software component which provides support for user of a computer system. • Can be used as personal assistants to filter mail, find useful documents, schedule meetings, do shopping for us. • The user delegates responsibility for some of their routine tasks to the agent, who is then responsible for ensuring they are carried out. • The agent should have some notion of the user’s goals, and be able to carry out the task autonomously • Making its own decision without asking, communicate with, find information from files, and adapt. • The agent might have to communicate with other agents, to find information form its environment and adapt what it is doing in response to information received. • Constantly active • Taking whatever actions are needed at a given time. Ch07A / 8

9. Software Agents: Example Mail Handling Agents • Many people get hundreds of e-mail messages a day. It is hard to sort the important messages from junk mail so programs that can automatically filter and classify mail are becoming popular. • Sometimes it is not clear whom to send a particular e-mail message to. • For example, we might want to send a message to the person who handles accomodation queries. • Message automatically forwarded to the appropriate person • It just allow each person to enter rules which specify how mail should be treated • For example, IF subject-line includes “dinner” THEN priority high; IF subject-line includes “broken” THEN forward-to-Fred. • A forward chaining engine might be used to process the rules and deal with the message. • Use techniques: • Natural language, not full understanding but just some analysis to try to identify the main topics in the message Ch07A / 9

10. Software Agents: Example • Machine learning to adjust the rules based on what user does with the messages. • Expert system Information Agents • Huge amount of information available on computer networks (such as through World Wide Web). • No time to constantly monitor the information available to see whether new information has appeared that is relevant to us. • Agent requires a personal profile giving the user’s interests. • Agents will do repeated searches to try to find information of interest, collate and prioritize the information, and present it to the user on request. • Operate in a changing environment, where the information available change from day to day. • Use techniques: • Expert system to identify relevant information • Machine learning to build and update the personal profile • Natural language to analyse potentially relevant texts Ch07A / 10

11. Software Agents: Example Agent-Based Interfaces • One new user interface paradigm is based on the idea that the user communicates with one of a number of conversational agents. • Conversation agent is an animated “talking head” that the user can communicate with using natural language. • User can get a response back, perhaps through speech. • Interface agent • May use information about the user’s particular needs and preferences and factual information about the user and the organization. • For example, the user might want to be able to say something like “Send this memo to all my customers in Klang valley”, and have the appropriate action done. • Need to be able to interpret the sentence and then access the relevant customer list. • May need to communicate with other agents in a system, such as mail and information handling agents. • For example, interface agent request an information agent to go and find information on a given topic. Ch07A / 11

12. Software Agents: Example • Special languages have been designed to allow communication between interacting agents, and knowledge representation formalisms developed to allow different agents to share their knowledge. • Agent-oriented programming is a programming paradigm that encourages thinking in terms of communicating agents rather than simply programming modules or applications. • Use techniques: • Knowledge representation • Machine learning • Natural language Ch07A / 12

13. Robots Robot • Term that is used for anything from the relatively simple programmable manipulators used for tasks such as car assembly, to the intelligent humanoid robots found in science fiction. • It carry out tasks for a human, but will have its own goal and will be able to adapt its behavior based on information received. • The main difference between a robot and a software agent is that the robot will be able • to perceive (by vision) objects in a physical environment • to manipulate objects in that environment • The main difficulty in designing robots is that the real world is messy. • It is easy to write a planning that can, in theory, work out how to move objects between room. • But in reality there may be • objects in the way of the robot (maybe a coffee table) • the environment changes (a human may sneak in and move the table • Not precise their action (how much did it move forward when the wheels slipped on the carpet) Ch07A / 13

14. Robot • Its visual perception uncertain. • Usage: • To explore or clean up in inhospitalable • Example robot for this • mobile • autonomous There are able to cope with unprediction occurrences and recover from error • Agents will do repeated searches to try to find information of interest, collate and prioritize the information, and present it to the user on request. • Type of robots which depending on their purposes: • Manufacturing robots • Autonomous mobile robots • Humanoid robots Ch07A / 14

15. Robots: Manufacturing Robots Manufacturing Robots • Robots are currently used in a variety of manufacturing tasks, such as welding, assembly and spray painting. • Example of this kind of robots is pretty dumb. • They just repeatedly execute some standard sequence of actions. • The design is consist of • A jointed arm with a device or end effector at the end of it, such as a gripper (to pick thing up). The arms are attached to a fixed base. • A paint sprayer or a welding gun For full flexibility, it has six degrees of freedom, three for x-y-z position and three for orientation • Programming involve the sequence of actions – move, touch, grasp and release on arm • May also use some basic visual from a camera • May, in a basic way, receive information from the environment and adapt their behavior accordingly Ch07A / 15

16. Robots: Autonomous Mobile Robots Autonomous Mobile Robots • A more interesting class of robot • Many applications require robots that can move around • This kind of robots are being used as delivery boys in large organization • They can be instructed to take some object from some location somewhere in the building, navigate their way about the building (avoiding obstacles on the way) and make delivery • They may also be used to do routine tasks in hazardous environments, such as the surface of Mars, the dangerous bits of a nuclear power station, or near a fire. • Often small unmanned land vehicles, underwater and aerial vehicles. • Autonomous aerial vehicles may be used, for example, to deliver food and medical supplies to refugees in a war zone, where human pilots are reluctant to fly. • Underwater vehicles may be used, for example, for oil exploration and maintenance of rigs. • Looks little like the human-like robots of science fiction. Ch07A / 16

17. Robots: Autonomous Mobile Robots • Autonomous Mobile robots • May be remotely operated by human who can see what the robot sees through its camera, and can directly control the movement and actions of the robot. • Normally operate in dynamic and unpredictable environments. • They able to perceive that environments, and take appropriate actions • Use techniques: • Planning and search to work out to get from one room to another, given a model of the world, but specialized low-level routines to actually carry out the actions. • Vision may be used to check and update the world model • Example: • Shakey • Firefighting Ch07A / 17

18. Robots: Humanoid Robots Humanoid Robots • Human-like robots of science fiction have complete with head, eyes, arms, hands, fingers and possibly even legs. • They can interact like human. • Example: Cog • Developed at MIT by Rodney Brooks and team • Has a human-like arm, a torso that allows it to bend over, twist around etc., a head mounted on a flexible nect, and two active eyes than can point in different direction. Ch07A / 18

19. Summary • Intelligent agents are independently operating computational systems that operate in some environment, and can adapt their behavior given new information received. • Autonomous agents can, to some extent, make their own decisions without reference to a human user. • Can divided into software agents, which operate in the world of computers and networks, and physical agents, or robots, which operate in the phsyical world • Software agents can act as personal assistants, handling mail, retrieving information, or just providing a human-like interface to application programs. • Autonomous mobile robots are mobile phsyical agents that operate indepently in the physical world. • Typical tasks include delivering goods in buildings and retrieving objects from inhospitable environments. • The development of agents operating in real environments has led to a change in emphasis in recent work in AI, with more emphasis on uncertainty, change, and managing simple tasks in realistic scenarios. Ch07A / 19