This deck is from my Robodev 2008 presentation on sensor fusion using open source technologies. It includes a detailed description of my homebrew sensor fusion Roomba, which I demonstrated at the conference.

1. Keith McFarlane keith dot mcfarlane at gmail dot com

3. Concepts

7. The Predict-Match-Update Cycle A model for fusing sensor readings into an actionable view of the world Transform Match Observations Update World Model Predict Sensors gather raw data about the world The data are put into some form that is compatible with the model The data are matched against / merged with previous predictions about the world The model is updated with the new data Predictions are reset based on updated model

9. Concepts

15. Scenario: Detecting Cheap Gas Rule: My Location within one mile of gas station with price under $2.75 and gas tank low Sends real-time changes in gas prices for a set of gas stations Gas Prices Service Event Processor “ Cheap Gas Nearby” Alert New Price New Price New Price New Price New Price New Price New Location New Location New Location New Location New Location Mobile phone GPS Location Service New Location Gas Level SMS

17. Sensor Fusion and CEP Conceptual Relationships Sensor Fusion CEP Collects observations Receives Events Requires normalized observation schema Requires normalized event data Dynamic world modeling Event stream maintenance Matching Event correlation/pattern detection Situational awareness Event pattern abstraction Symbolic fusion Event schema Used to model the world using limited data set and predictive feedback model Used to detect specific situations

20. Esper Container Architecture Events Source: http://www.espertech.com Esper Lightweight CEP Container Event Stream Connectors and Adapters Historical Data Access Layer Container Core Event Query and Pattern Language Executive Event Query and Pattern Language Esper Engines Statements Statements Statements Statements Statements POJOs Output Adapters

22. EPL: Familiar Concepts from SQL Clause Description SELECT Indicates an that events should be selected based on a set of criteria. Can select on insert stream, remove stream, or both. FROM Defines the event stream(s) or named window(s) from which events should be selected WHERE Allows filtering of events based on a wide range of criteria GROUP BY Allows stratification of events by a set of characteristics HAVING Filters groups specified by the GROUP BY clause INSERT INTO Creates new events in the given named window, allowing events to cascade through the system

27. Hardware El Cheapo Laptop Roo232 USB-to-Serial Cable Roomba Sage Reversed Mac Mini-DIN 8 M2M Cable

29. The Command Pattern

30. EventBot Data Flow vs. Fusion Model Roomba Events Commands Roomba Connector Event Transformer Esper CEP Event Listeners Transform Match Observations Update World Model Predict World Model

33. email: keith dot mcfarlane at gmail dot com