1. Workshop on Smart Object Systems Dietary-Aware Dining Table – Tracking What and How Much You Eat Keng-hao Chang, Shih-yen Liu, Jr-ben Tian, Hao-hua Chu, Cheryl Chen National Taiwan University

2. Workshop on Smart Object Systems Why Dietary-Aware Dining Table We are what we eat. –Our everyday food choices affect our long-term and short-term health.

3. Workshop on Smart Object Systems The food tracking table Track food consumption of multiple users over a table by –Identify food items by RFID-tagged containers –Track food transfers by monitoring weight changes over a weighting surface

4. Workshop on Smart Object Systems Related work Lancaster’s load sensing table –Objective: track object’s location over the table –Method: track the object by its center of weight Dietary-aware dining table –Objective: monitor food consumptions over the table –Method: monitor the food path by weight transfer detection

5. Workshop on Smart Object Systems How does the magic surface work? Two examples

6. Workshop on Smart Object Systems Example Scenario 1 (1/2) Bob cuts a cake from the share plate to personal plate, and eats it Detect cake transfer from one container to another container 1)Identify the presence of plates RFID tags on containers tag-food mapping 2)Track cake transfer Weight change detection Weight matching

7. Workshop on Smart Object Systems Example Scenario 1 (1/2) Pour tea? Weight increases w 2. Bob pours tea from the tea pot to personal cup, and drinks it Pick up tea pot. RFID tag disappears Weight decreases w 1 Put on tea pot. Pour tea! RFID tag appears Weight increases w 1 -w 2

8. Workshop on Smart Object Systems Example Scenario 1 (1/2) Bob pours tea from the tea pot to personal cup, and drinks it Pick up cup. RFID tag disappears. Weight decreases w 1. Put on cup. Drink tea? (only if no match) RFID tag appears. Weight increases w 2.

9. Workshop on Smart Object Systems Example Scenario 2 (1/2) Bob pours tea & Alice cuts cake Pour tea? Cut cake? Weight change w Pour tea Weight increases w 1 Cut cake Weight decreases w 2

10. Workshop on Smart Object Systems Example Scenario 2 (2/2) Multiple, concurrent person-object interactions –The larger the cell, the higher possibility of concurrent interactions over a cell –Cell size ≈ average size of container –Reduce the possibility of concurrent interactions over one cell

11. Workshop on Smart Object Systems System Archietecture Bottom-up event triggered inference, JESS Cake transfer from share plate to personal plate Share plate weight decrease w Personal plate weight increase w Share plate on cell j 1 cell j 1 weight decrease w personal plate on cell j 2 cell j 2 weight increase w

12. Workshop on Smart Object Systems Conclusion & Future work Simple prototype automatically tracks what and how much each individual eats. Identify users other than by the personal plates The reliability of the system –Weight matching method –Weight increase from the world outside of the table Cross cell problem Further reliable way to infer food path Build LEGO like component

13. Workshop on Smart Object Systems Thank you Any question? If you have further question, please email me: Keng-hao Chang (khchang@csie.org)