Bringing Safety and Security to Battery-less Smart Clothes Shilin - PowerPoint PPT Presentation

Bringing Safety and Security to Battery-less Smart Clothes Shilin Zhu Apr 2017

Questions To Be Answered • Is the current user the secure owner of smart cloth? • Is the user having safe interaction with the environment and other people?

Three Technical Questions • How to sense the security and safety ? • Wireless, Computer Vision, Electrical, Pressure … • How to actively react to danger by clothes? • Display, Physical, Communication … • How to make the cloth battery-less? • Energy Harvesting: RF, Solar, Temperature, Motion, …

Is the current user the secure owner of smart cloth? Distributed Capacitance / Sound Pattern Impedance Recognition Across Body Motion and Deformation Tracking Infrared Emission

Is the user having safe interaction with the environment and people? Smart Pocket with Capacitance Outdoor Traffic Monitoring and Light Safety Sensing Radiation Absorption Pre-Collision (Asymmetric) System Body and External Pressure Monitoring Disabilities Space Suit Guide and Track Appearance Adaptation Weather (For Soldiers) Forecasting

How is such smart clothes made of ? Smart Communication Conductive Textile Power Supply Unit with (Passive or Active) Computing Unit Stretchable and Washable Electronics, Safety Reaction Sensors and Display Components Tactile Motion Pressure Attachments Display Report

What kind of designs do we need? Reliable Cloth-Mobile Distributed On-Body and Cloth-Attachment Capacitance, Shadows Communication and Vital Signs (e.g., cloth-watch) Computing and Action Classification Overcome Frequent 360 Degree Interference on Clothes Environmental (environment or human) Learning and Strategy Sensor Distribution Based on Cloth Signal Injection and Dynamics Extraction on Clothes (stretchable, rigid, …)

Customized In-Cloth Smart Tag Stretchable and Washable Tag Active Antenna for BackScatter Safety Reaction Energy Capacitance Sensing Sensor Panel (Unique Frequency Point) Module (e.g., LED, Harvesting (Similar as LiveTag) (e.g., PD, OR Active Transceiver Stretchable Display) Module Sonar) 3D Printed Inside Cloth with Conductive Textile Deformation Dependent Response Combined with Cloth Dependent Phased Array Response

Must do Both Active and Passive Ways Tag Returns In-Cloth Simple Tag Returns Environment Body Information Controller Information with Energy Controller Harvesting Smart Tag Reader (Frequency Sweeping) Computing Passive for the Body Active for the Environment

Both Wireless (WiFi, mmWave, Visible Light) and Wired Visible Light Body Wireless Controller Channel Wireless Environment Wired Channel Conductive Fabrics Wireless Reader Wireless Channel Attachment Channel

On-Body and On-Cloth Safety and Security Network Safe? Secure? Safe? Safe? Like a On-Body SDN Controller Safe? Safe? Highly Connected Light-Weight Tags/Controller Safe? Safe? Tag Works Both Like an Safe? Safe? Integrated Sensor and a Router Safe?

NFC BackScatter No Longer Needed for Passive Sensing MIMO Patch Antenna Time Multiplexing and Pipelining BackScatter NFC Power Ultrasonic Sensor? Pocket Microphone Capacitance Sensing NFC Energy Storage Tag Coil LED Magnetic Conductor Sensing

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Security and Safety Oriented Data Analysis • Capacitance Tag: Body and Motion Monitoring • Microphone: Human Talk, Car Engine • MIMO Patch Antenna: Obstacle Detection • Magnetic Coil: Conductors Secure? Safe?

Power • Cloth itself is Battery-less (Harvested from NFC since others are too unreliable) • Energy Storage System is used for Maintaining Power Supply (Overcome NFC Coupling Dynamics when Smartphone is in the Pocket) • Time Slot and Pipelining: Power and Latency Reduction • We Simplify the Circuits used for Data Receiving (e.g., avoid using Micro-controllers) , mW Level (NFC provides W Level)

Two Modes Active Mode: It works like a Smartphone-Powered Radar and Metal Detector - Safety Whether NFC has the ability to power the entire active system is a question. Passive Mode: It works like a Large Backscatter Device - Safety Environment must emit some signals that can be passively received.

This is still energy harvesting, the smartphone is powering the entire system. I do not know if the system drains the phone’s battery slow or quick. If quick, then it is worse than directly embedding a battery (Smartphone needs to do better things like phone calls).

Why Not Camera for now? • Cannot be further made stretchable for now • Need high resolution to do image recognition • More Power Consuming • Sending a 8MP image back through NFC is impossible for safety applications, need to add a video streaming unit • Won’t work during the night which is very important for safety applications

Long-Wave Magnetic Field Sensing Environment Conductive Other Non-Conductive Objects Objects (Object can be Passive) (Object must be Active)

Magnetic MIMO Beamforming: MagMIMO (MobiCom 2014, 1MHz) and MultiSpot (MobiCom 2015, 1MHz) Existing Magnetic MIMO is Used For Wireless Charging, Not Sensing They are Focusing on Circuits, Not Mag Field Formula We also Need to Measure the Relative Motion (Tracking) to Do Classification

Magnetic Beamforming n { } ∑ a i ⋅ e j θ i ⋅ x i H beam = i = 1 H coil ∝ I coil

Frequency • Rubee Uses 131 KHz • Disney Research Uses 360 KHz - 50 m, Single Coil • MagMIMO and MultiSpot Uses 1 MHz (Wireless Charging)

Why Long Wave Magnetic Signals? Behind the Obstacle Especially Steel MultiPath-Free Ultra Low Power (RF may get blocked) Reasonable For IoT Suitable For IoT Safety e.g., Powder Apps Safety Issues Magnetic Field is Safer than Are Always Hidden Electrical Field

Object - Object & Human-Human & Human-Object

3 Modes Active Half-Active Half-Passive

Do We Need Magnetic Channel Estimation? ' = V i / I i α 1 x Real( α 2 ) = Img( α 1 ) Real( α 1 ) Img( α 2 ) = M 1 Z i M 2 M1 ' − Z 1 M 1 Z 1 = ' − Z 2 M 2 Z 2 α 2 x 2 Coils: M2 M1/M2 determined by pre-computation/pre-training, based on object classification? How M1/M2 changes with receivers at same location/angle?

Simple Sim (Single Coil & a Metal)

Smart Pocket • RF Solution: In-Pocket Antenna Connected to the Cloth Antenna (Use WiFi?) • Magnetic Solution: In-Pocket Magnetic Coil • 2 Functions: • Classification: User’s Own Hand OR Stranger’s Hand • Track Things (Either Conductive Or Non-Conductive) In the Pocket

Challenges • Passive Ways are Limited to Conductor, Otherwise Need an Active Mag Tag Powered by Battery or Energy Harvesting Attached to the Object • Range, Antenna Size and Shape Dynamics, Magnetic Core • Poor Directionality Unless MIMO • Bandwidth is Limited • Separate Multiple Signals (Multiplexing?) • Magnetic Signal Modulation (Specific Time-Varying Magnetic Field) • Receiver Side is Totally Unknown, Making Mutual Inductance Computation Very Hard (Assume multiple M when Calculation? Beam Scanning Algo?) • Unpredicted Environment Impact

Magnetic Signal Ad-Hoc Sensing Max Max Safety Sensing Range Range Tranceiver Passive Active Active Active Pocket Conductor Mag Tag Mag Tag Mag Tag & Router & Router

Power • Battery (can last for 5-25 years?) • Energy Harvesting (Indoor: WiFi, NFC, Magnetic; Outdoor: Solar, NFC, Magnetic • Battery Fabrication: Flexible Printed Battery may be Used since RuBee does not Require Much Power One-Time Recharging for Several Years?

Antenna • Self Magnetic Loop Antenna • Without Steel Magnetic Core? Should be Easy to Be Printed • Make Attached Conductor as Antenna (e.g., Human Body, Steel, …) • How to Sense the Direction of Magnetic Source? And Distance?

Range • Limited: Maximum 20 meters (in air, maybe), Otherwise We need Higher Power? • Could we Use Multiple Objects to Do Ad-Hoc Magnetic Transmission (e.g., Act as Routers as well)?

Thanks