UNIVERSITY OF HERTFORDSHIRE COMPUTER SCIENCE RESEARCH COLLOQUIUM "EMBER: Reinforcement Learning in Embodied Agents" David Jacob School of Computer Science University of Hertfordshire 26 October 2005 (Wednesday) Lecture Theatre E350 Hatfield, College Lane Campus 3 - 4 pm Coffee/tea and biscuits will be available. [Catering Permitting] Everyone is Welcome to Attend [Space Permitting] Abstract: Reinforcement Learning is a seductive idea: by simply providing an agent with rewards to indicate whether it is doing what we want or not, it can be trained to perform any task which can be represented as a Markov Decision Process. However the size of state and action spaces makes learning very slow and thus renders the approach impractical for any realistic embodied agent. Various methods have been proposed to make learning more tractable. My research focusses on the decomposition of agents into modules based on the details of the agent's embodiment: these modules sense, act and learn independently. This has a number of desirable outcomes: it makes learning practical, it allows the agent to learn a set of transferable competences which can be brought to any task, and it provides a simple mechanism for controlling (or `shaping') the agent's behaviour to improve learning rates and task performance. In addition, the small state spaces and close coupling of action and reward enable adaptive action sequences to be learned, making for more usable skills than are typically achievable using open loop control. We demonstrate this generic skill learning using a simulation of a quadruped walker robot which learns a dynamically stable gait and performs it in a system with billions of states. This works was carried out in the Adaptive Systems Research Group as part of a PhD under the supervision of Drs. Daniel Polani, C. L. Nehaniv, and David Lee. -- Hertfordshire Computer Science Research Colloquium http://homepages.feis.herts.ac.uk/~nehaniv/colloq