Design Team Design Team 55

Lowering Standby Power Lowering Standby Power Consumption Via Consumption Via

Proximity DetectionProximity Detection

Kevin Harrison

Leslie Hodges

Eric Hosey

Nathan Kelly

Berna Saracoglu

• Anticipated ENERGY STAR standard– Appliances need to operate under one

watt in standby mode– Current appliances do not utilize

standby mode– Standby mode would diminish customer

experience

• Need to smoothly enter and exit an energy ethical standby mode to lower energy consumption

The The ProblemProblem

• Detection of user presence– Implement a variety of

sensors for in room and potential appliance use detection

• Low-to-mid range and High-end options– Laundry and kitchen

appliances– Cost differences– User experience

When you walk When you walk into your kitchen, into your kitchen, your kitchen turns your kitchen turns

onon

Our Our GoalGoal

• Power– Less than 1 watt in standby mode

• Size– Fit aesthetically into appliance and room

• Cost– Limitations dependant on appliance price

• Flexibility– Adapt intelligently to different environments– Current and future appliances

• Accuracy– Not interfere with appliance functionality– Not susceptible to interference

• Safety– Product used by general public

Design Design SpecificationsSpecifications

Low-to-Mid Range• Two sensors

– Passive infrared (PIR) sensor• Monitors room for user presence

– Active infrared (IR) sensor• Monitors for potential use of appliance

• Integration– In standby mode PIR will monitor room– Detection of user will turn on IR sensor– Detection of potential use will exit from

standby mode

Design Design SolutionsSolutions

High-End• Two sensors

– Passive infrared sensor• Monitors room for user presence

– Ultrasonic sensor• Capable of calculating user proximity• Information density

• Integration– In standby mode PIR will monitor room– Detection of user will turn on ultrasonic sensor– Will exit standby mode as user approaches appliance

Design Design SolutionsSolutions

IR Sensor• Very low cost• Detection up to 4 ft

– Very little span• Consumption less than 0.2

W• No false triggers

Ultrasonic Sensor• Detection up to 20 ft

– Span of appliance width• 10 mW consumption• Susceptible to false-on

triggers from air motion

Sensor Sensor SelectionSelection

PIR Sensor• Power consumption of 0.5 mW• Very low cost• Detection up to 20 ft

– 180° hemispheric detection• Resistant to false-on triggers• Ideal for both design solutions

Sensor Sensor SelectionSelection

• Expected 1 watt standard• Currently can save 35% with

refrigerator user interface

Power Power ConsumptionConsumption

• Voice commands– Physically disabled– Safety

• Voice announcements– Visually impaired– Appliance status

• LCD solution– More common in future– Proximity sensing improves power

consumption and marketability

Future of Future of ProductProduct

Questions

?