Development of a Sensor Database System for

Communication Robots

Hideyuki KAWASHIMA

Graduate School of Keio University

Yokohama, JAPAN

Background:Human-Robot Communication

• Sensors– Video

– Microphone

– Touch sensor

– Ultrasonic sensor

Required properties

• Monitoring sensor data during experiments

• Persisting precious sensor data immediately

• Retrieving similar sensor sequences

Problem formulation

1. Continual query

2. Freshness of data

3. Similar sequence retrieval

Problem1: Continual query

DB

MonitoringClient

Sensor

Data 1Data 2Data 3

DBMS

IPC waste & period lag

Backend

Problem2:Freshness of Data

Log file

Databasebackend

BufferPool

Sensor Process

Stale data because of Tardy disk access

Problem3:Similar Sequence Retrieval

• Metrics– Euclid:– Dynamic time warping: MIN{ }WkΣ

K

1 2 3 4

4

3

2

5

Wk = A distance on a path

9

4

1

4

1

0

1

0

1

0

1

4

16 9 4 1

2

1

5

4

23

34

(Di-Qi)Σ 2 = 2= 2/5√

My approach: Extending RDBMS for problems1. Continual query

2. Freshness of data

3. Similar sequence retrieval

Continual query

DB

MonitoringClient

Sensor

Data 1Data 2Data 3

DBMS

MonitoringBackend

Register CQ

TransferBackend

Efficient IPC & Exactly periodic monitoring

Freshness of data

Databasebackend

BufferPool

Sensor Process

Remote log server& Check pointer

Network

Similar sequence retrieval

• Select sonar from robovie where simseq external [1,2,3] with dtw < 10

id12

Experiment_date01/05/200402/05/2004

sonar

1 2 3Sliding window:

Design of KRAFT

Trans. Mgr

Mem. MgrIndex Mgr

Storage Mgr

Parser Executor Recovery Mgr

Lock Mgr

Local Log MgrConn. Mgr

Remote Log Mgr

Mem. Mgr

Client

TCPTCP

Over 17000 lines by C

Future directions

• Enhancing analytical methods for sensor data

• Scalability for continual monitors

• Accelerating query processing– Index for similarity retrieval– Parallel execution– Device conscious

Summary

• Motivation– Management of data for human-robot interactions

• Problems– Continual query– Freshness of data– Similar sequence retrieval

• My approach– Extending RDBMS for problems

• Future directions