Happy Home Helper

Jeremy SearleApr 28, 2004

A Learning Home Automation System

Background

Home Automation is used for various household controls (lights, security, entertainment)

Systems tend to be expensive Systems completely rely on the home PC which

can be unreliable (Hackers, Crash, Power Surge, Virus)

Systems must be programmed to accomplish tasks and do not learn

Problem Statement

To design a home automation system that is capable of learning and executing daily routines at an

economical cost.

Solution

Central micro-controller unit Outlet control modules PC user interface Sensors to sense human presence (Motion & E-Field Sensors) Monitors power consumption and usage of devices plugged

into Outlet control modules Wireless communication between devices Computer controlled window mechanisms Computer controlled window blind mechanisms

System Overview

Central μController

Outlet Module

Outlet Module

Data Flow

Human InputMisc.Sensors

Outlet Module Overview

Serial Input/Output to/from Central μController

Power from wall outlet

Current Sensor

Relay

Device to be controlled by

Outlet Module

μController

AC/DCconverter

Serial Input/Output to/from Peripherals (sensors, actuators) X2

X2

Outlet Module State Machine

OFF

Manual_______

_______

Auto ON

Auto OFF_______

_______

_______State

0 0__________

Relay

Get Power Reading

0 0

1 1

1 1

0 0

0 – NO1 – YES

0 – OFF1 – ON

M – Manual Mode

N – Auto Mode ON

F – Auto Mode OFF

M

M

F

F

N

Outlet Module Circuit

Current Sensor Readinghighest sample = 0lowest sample = 255

Wait 250 ms to let current spikes settleLoop for 64 ms{ Take an A2D sample

If current sample > highest samplehighest sample = current sample

If current sample < lowest sample lowest sample = current sample

}power = (highest sample – lowest sample)*K

Note: power accuracy is 0.125A or 15W if K = 2

Window Blind Actuation Modes

-Manual-Ambient Light Tracking

Close blindsOpen blinds until Light = desired

Every 10 minutesIf reading is lower than desired

Open blinds until Light = desiredIf reading is greater than desired

Close blinds until Light = desiredIf reading can not reach desired

Close blinds all the wayTake pre-determined action

-Maximum Light TrackingEvery 10 minutes

Open blinds all the wayClose blinds while recording measurementIf next reading is lower than Max

Stop blind movement

Central Micro-Controller Overview

Serial Input/Output to/from Outlet Modules

Serial Input/Output to/from PC

NVRAM

uController

RTC

How does it learn?

The system learns by collecting usage statistics from the outlet modules. It then runs a pattern recognition algorithm to look for:

-Devices that are used immediately following another device-Devices that are used at the same time of day habitually

The system will then suggest that it takes control ofthese devices to help the user.

NOTE: The system will never take control without the users consent

System Pros and Cons

Pros

-The ability to automate household devices with a PC interface at a nominal cost-The ability to monitor devices’ power consumption and usage -The ability to assist the user by recommending applications-The system learns, but the control remains completely in the hands of the user-The Outlet modules and the window blind actuation mount in seconds and require no tools to install-The system will record usage and power consumption statistics without the PC

Cons

-The system does require some thought preparation about which devices to control-The window actuation and the sensors require mounting-The system will not learn without the PC

Just a couple applications

Set up a temperature sensor, window actuator, and a fan plugged into anOutlet module in a desired room.

When the temperature gets too hot (user sets ‘too hot’ temp.) 1) Open the window

2) Turn on the fanOnce the temperature gets cool again

1) Close the window2) Turn off the fan

Set up a window blind actuator, a motion sensor, and a lamp plugged into an Outlet module in a desired room.

When the window blind actuator can’t get the desired light intensity1) Close the window blinds all the way2) Turn on the lamp3) When the user is inactive for 30 min. turn off lamp

When the time comes the next morning1) Open the blinds to allow light

Thank You

Any Questions

?

Email me at jsearle@vtc.edu