Architecture of Intelligent Systems - 1 24 Jul 2012 Plan for the Lecture •I S course – objectives, Arch of Int systems •AI Vs Intelligent systems •Analyse a few systems and get an intuitive feel for the intelligent systems •Intuitive understanding of Intelligent systems •Understanding the generic characteristics of the intelligent systems •Identification of functional subsystems or blocks What is an Intelligent System? It is a concept It is a System that exists It learns during its existence It senses its environment and learns - for each situation, which action enables it to reach its objectives It continually acts, mentally and physically or externally By acting it reaches its objectives It is autonomous in the sense that it decides its intermediate objectives (to reach its original objectives) and plans its actions to reach those objectives, evaluate the consequences of its actions (by sensing the environment and judging whether it is a desirable/ expected state) The actions are deliberate than by chance It consumes energy and uses it for its internal processes, and in order to act Its actions modify the environment What does this definition imply? The system has to exist. •An environment must exist, with which the system can interact. •It must be able to receive communications from the environment, for its understanding of the present situation. It must be able to process the sensed information and build the model of the environment. It must be able to abstract the communications received by the senses. The communications, in turn, need an interchange of matter or energy. This communication is for the purpose of transmitting information or for the specific purpose of structuring of matter in the environment (that the system perceives). •The IS must have an objective whether given or set by itself. Capable of setting its objective consistent with its original objective. it must be able to check (or aware) whether its last action was favorable or has desired impact on the environment or whether it resulted in getting nearer to its objective, or not. •To reach its objective it has to select its response. A simple way to select a response or an action is to select one that was favorable in a similar previous situation. But it may have to reason it out in new situations. •It must be able to learn. Since the same response sometimes is favorable and sometimes fails, it has to be able to recall in which situation the response was favorable, and in which it was not. Therefore it stores situations, responses, and results. •Finally, it must be able to act; to accomplish the selected response. It is autonomous Does it mean it has free will Does it have likings? Should it know its own capabilities When should it give up or when should it pursue an objective Where do we need Intelligent systems Intelligent Systems (methods) are used in science and industry with a wide variety of applications involving the following areas: intelligent robotics, health monitoring applications, speech and language interfaces, financial forecasting and prediction, internet and agent technology, image processing, planning and scheduling, knowledgebased systems, security and fraud detection. AI has given us • Parsers, theorem provers, inference engines • Tools – searching, classification, statistical, pattern matching, abstraction, translation • Tools – problem solvers, game playing, modelling, robotic guidance • Technologies – neural networks, knowledge acquisition, expert systems, planning, dialogue generators The above are integrated into General purpose applications What has it not given us? How to build intelligent systems by integrating the above components and techniques. Reasons Emulation of Human Intelligence is difficult Human Intelligence is highly flexible and so no unique architecture is possible for all No comprehensive architecture exists as we have not attempted to solve a problem in its entirety We can only simulate one aspect/behaviour at a time Intelligence Architecture Intelligent systems Intelligence Reflex/ known response Understand, interpret and respond Perceive, analyse, respond Respond under unknown and uncertain environments Perceive, analyse, generate knowledge (about the world)(is it learning?), use knowledge and respond Plan, compete, Plot, scheme Evaluate alternatives, judge values?, value system or beliefs Set goals for success (who decides the criteria of success?) Intelligent systems – Examples Smart dwellings, Smart space, Smart vehicles, Intelligent ground, underwater, space exploratory vehicles Cave bursters, Humanoid robots, Pilot-less plane Smart manufacturing plants Smart security devices – campus security, access to classrooms and labs – attendance, entry control, switching off devices, Vehicle/individual movement an tracking, surveillance Smart SW to locate other SW At what stage do we call a system intelligent Contd. ITS Intelligent SW agents Code generators/translators/ Symbolic computation Conversational engine ELIZA Game engine - Chess engine Semiotic engines Intelligent networks Intelligent systems are Autonomous – self governing, no external intervention over extended periods, Able to work in unpredictable environment – sense the environment, decision making, control action Adaptive Fault tolerant Functionality in noisy environment Autonomy is objective & Control is a means of achieving it Contd Planning Learning Re-structurable/re-configurable systems Value judgements Embedded systems Real time control systems Control may be in either hardware or in software Outline for a theory of Intelligence IEEE transactions on systems, man, and cybernetics. Vol 21, No 3, May/June 1991 J S Albus Intelligent Systems – Architecture, Design and Control. Albus, Meystel, wiley, 2002 Daniel Dennett. Brainchildren: Essays on Designing Minds. MIT Press, 1998. Intelligence – Ability to act appropriately in an uncertain environment Appropriate action increases probability of success or decreases the probability of failure in the achievement of behavioural goals. Who generates the criteria for success and the goals? - Within the IS? or the environment in which IS operates? Levels of Intelligence Sense the environment, take decisions, and control action Recognise objects and events, Store and use knowledge about the world, to reason, & to plan Perceive and analyse, generate knowledge – learn, plot and scheme, choose wisely from alternatives, judge values Plan successfully in a complex, competitive and hostile world. What determines the amount of intelligence Computational power of the computing engine Sophistication and elegance of the algorithms Amount and quality of information and values Efficiency and reliability of the system architecture Amount of natural intelligence can grow through providing knowledge learnt through experience evolved through experience passed on through generations Can the Intelligent systems Intelligence grow through the same approaches i.e. programming, learning, evolution (modification & genetic)? Evolutionary Intelligence is a product of natural selection! Passed on to next generation, follows natural selection. In natural selection less successful behaviour dies out, more successful behaviour is retained and passed on to the next generation. Natural selection is driven by competition of the individuals in a group & of groups in the world How do we implement evolutionary intelligence in machines? How do they pass on this intelligence to next generation? What are the functional blocks of an intelligent system? Sensing the world – sensors Sensor information and value processors World knowledge generation, storage, retrieval Knowledge processors & computational engine Inference engine/Reasoning engine & Decision Support system Actuators Control engine