Cyber-Physical Systems: Issues and Challenges Rabi N. Mahapatra Texas A&M University (Adopted from...

Cyber-Physical Systems:

Issues and Challenges

Rabi N. MahapatraTexas A&M University

(Adopted from NSF Workshops)

April 18, 2023 1WECON 2011

http://www.cs.tamu.edu/

April 18, 2023 WECON 2011 2

Overview

What are Cyber-Physical Systems? Emerging Context: Applications,

technical & Economic Issues & Challenges Application Specific Research

Identification Summary


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What are Cyber-Physical Systems?

What are CPS?– Are they desktop computers?– Are these traditional, post-hoc embedded/real-time systems?– Are these today’s sensor nets?

Ans: None of the above!

• Some defining characteristics:– Cyber capability in every physical component– Networked at multiple and extreme scales– Complex at multiple temporal and spatial scales– Dynamically reorganizing/reconfiguring– High degrees of automation, control loops must close at all

scales– Unconventional computational and physical substrates (Bio?

Nano?)– Operation must be dependable, certified in some cases


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Economic Context: US & EU Competitiveness American Competitiveness Initiative announced:http://www.whitehouse.gov/stateoftheunion/2006/aci/

EU Framework Programme 7, European Research Council, and related actions

• ARTEMIS– Backbone of European Research Area for Embedded Systems,http://www.artemis-office.org/• Strategic Research Agenda (SRA)• Joint Technology Initiative (JTI)• Embedded systems education and curriculum– “High-Level Group”• CEOs: ABB, Airbus, Nokia, Parades, British Telecom, COMAU, Philips,Bosch, Continental Teves, Daimler/Chrysler, ST Microelectronics,Symbian, Ericsson, Finmecanicca, Telenor, Thales, IMEC, Infineon• Universities and national research labs: TU Vienna, CNRS/Verimag– Joint public and private funding


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Example: Health Care and Medicine National Health Information Network, Electronic Patient Record

initiative– Medical records at any point of service– Hospital, ICU, …, EMT?• Home care: monitoring and control– Pulse oximeters (oxygen saturation), blood glucosemonitors, infusion pumps (insulin), accelerometers(falling, immobility), wearable networks (gaitanalysis), …• Operating Room of the Future (Goldman)– Closed loop monitoring and control; multipletreatment stations, plug and play devices; roboticmicrosurgery (remotely guided?)– System coordination challenge• Progress in bioinformatics: gene, proteinexpression; systems biology; disease dynamics,control mechanisms

Images thanks to Dr. Julian Goldman, Dr. Fred Pearce


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Example: Electric Power Grid

Current picture:– Equipment protection devices triplocally, reactively– Cascading failure: August (US/Canada)and October (Europe), 2003

Better future?– Real-time cooperative control ofprotection devices– Ubiquitous green technologies– Issue: standard operational control concerns exhibit wide-

area characteristics (bulk power stability and quality, flow control, fault isolation)

– Context: market (timing?) behavior, power routing transactions, regulation


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Example of a CPS concept (fiction)

Weebo – from the movie ‘Flubber’Concept : Personal Assistant

Flubber © Disney Motion Pictures 1997

Application Example


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Fiction becomes reality

NASA – Personal Satellite Assistant (concept)

•Will help astronauts in space

•Will have built-in propulsion and navigation

•Can go to difficult to reach places

Personal Satellite Assistant © NASA Ames Research Center

Application Example


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Personal Satellite Assistant

•The PSA is about the size of a softball

•Has sensors for measuring gases, temperature, and air pressure.

•PSA can video conference & communicate with electronic support devices such as computer servers, avionics systems, and wireless LAN bridges.

•PSA is a robotic assistant for astronauts working in space.

Artist’s concept of a PSA assisting an astronaut

Images © NASA Ames Research Center

Prototype


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Defining Cyber-Physical Systems:

A cyber-physical system integrates computing, communication and storage capabilities with the monitoring and/or control of entities in the physical world dependably, safely, securely, efficiently

and in real-time.

Seek scientific foundations and technologies to integrate cyber-concepts with the dynamics of

physical and engineered systems.


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Long-Term Goal

Transform how we interact with the physical world just like the internet transformed how we interact with one another. Transcend space and yet control the

physical environment

Produce significant impact on society and national competitiveness.


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Industry Sectors To Benefit

Automobiles Industrial Automation Energy Defense and Space Intelligent Homes and Health/Medical Equipment

Other Sectors to benefit:• Telecommunications• Consumer Electronics


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Possible Cyber-Physical Systems

Medical devices and health management networks Tele-physical operations Vehicular networks and smart highways Physical infrastructure monitoring and control Electricity generation and distribution Robotic manufacturing Aviation and airspace management Defense and aerospace systems …

In general, any “X by wire(less)” where X is anything that is physical in nature.


Issues & Challenges

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Fundamental Challenges

From a synthesis perspective Architecture Requirements and their management Formalization of the constraints imposed

by the Physical layer (physical – cyber interface and boundary)

Grand Challenge:Compositional approach to Cyber-Physical

Systems Design and Synthesis.


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From IT Abstractions to “Hardware/Software”

From DNA‘programs’ toliving organisms

From CAD schematics to chips

ISR-SEIL, Copyright © 2006


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From IT Abstractions to “HW/SW”

No difference between HW and SWHW/SW co-design,, software radios


From algorithms and schematics to radios

Embedded systems design tools

Picoradio

R-50 Hovering

INS

GPS Antenna

GPS Card

UAV Controller


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A Glimpse into the Future Autonomic wireless networks, self-organizing collaborative robotics,

self assembled systems and materials Computing over new Physical domains

(Quantum, organic, biological) •from abacus to qubits• entanglement• nuclear spin, electron spin• photon polarization, ion trap

As dimensions getsmaller what is cyberand what is physicalgets fuzzier

From material layercontrolled by cyber layer

to “programmable matter”

True convergence ofControl, communicationcomputing

•Communicating minds

•Swarm intelligence



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Areas of Challenge

Communication between the components

Data Storage & Retrieval Data Security Scalability Management of the CPS devices User Interfaces Safety


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Communication

Large amounts of data transfer will be required

Will need enhanced wireless protocols which support Low power consumption

(can power criteria be part of the protocol ? ) High Bandwidth High Data Transfer Rates Intelligent traffic management and

routing.

Image © davisdrive.wcpss.net

Challenge > Communication


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Will require robust security to protect the data that is to be transferred.

Should be light on computational and memory requirements.

Should be able to gracefully degrade in case of attacks.

Can we have self-quarantining of compromised sections/areas ?

Communication-SecurityChallenge > Communication

NSF Workshop, Austin, October 17, 2006


April 18, 2023 WECON 2011 22

Data Storage & Retrieval

Depending on application Monitoring type application

low quantity on individual nodes Interactive application

possibly huge amounts of data stored

Should adopt distributed storage algorithms

Algorithm selection cannot be generic, will be application specific.

Image © NeoScale Systems Inc

Challenge > Data Storage & Retrieval


April 18, 2023 WECON 2011 23

Scalability

CPS will be a global, open & extensible platform

Questions: How do we describe, discuss, deduce the

invariants of such a global system ? How do we model the expansion of such

a system ? How will such a system scale to

planet-wide use and deployment ?

Challenge > Scalability


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Management of CPS

How do we deploy and control large scale applications ? Wireless networks that can perform self-

organization. Adaptive routing protocols for traffic

control and efficient routing. Multiple smaller deployments that

collaborate into one large network . (an Internet of CPS ?)

Image © www.niaid.nih.gov


Safety of Cyber-Physical Systems

April 18, 2023 25WECON 2011


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Interactive Complexity Two dimensions− Coupling: Tight vs. Loose• Delay and ordering tolerance,resource slack,inherent buffering (vs. designed in)− Interactions: Complex vs. Linear• Degree of feedback, number of common modeconnections, limited system understanding, relianceof human expertise, many control parameters Systems with high interactive complexitypossess numerous hidden interactionsthat can lead to systems accidents− Nuclear Power Plants− Chemical Plants− Software Systems System Accident: The halting of systemoperations due to damage or failure ofmultiple subsystems that arises from theunanticipated interactions of multiplefailures


April 18, 2023 WECON 2011 27

Cyber Physical System Accidents

USS Yorktown(http://www.slothmud.org/~hayward/mic_humor/nt_navy.html )

− Suffered a systems failure when bad data was fed into itscomputers during maneuvers off the coast of Cape Charles,VA.− The ship had to be towed into the Naval base at Norfolk,VA., because a database overflow caused its propulsionsystem to fail− ”We are putting equipment in the engine room that wecannot maintain and, when it fails, results in a criticalfailure," DiGiorgio said. It took two days of pier-sidemaintenance to fix the problem.


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Accident due to SW Bug

Ariane Five(http://www.ima.umn.edu/~arnold/disasters/ariane5rep.html)

Ariane 5 reused a module developed for Ariane 4, which assumed that the horizontal velocity component would not overflow a 16-bit variable.− This was true for Ariane 4 but not for Ariane 5, leading to self-destruction roughly 40 seconds after the launch.− “The [Ariane 5] alignment function is operative for 50 seconds after starting of the Flight … This time sequence is based on a requirement of Ariane 4 and is not required for Ariane 5.” (Report by the Inquiry Board)


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Interactive Complexity in Cyber Physical Systems Cyber Physical Systems Typically Have High Interactive Complexity− Many tightly coupled system threads with hard deadlines− Shared resources among mission critical and non-mission critical systems− Give rise to numerous hidden dependencies, which then lead to unexpectedfunction, performance, or accidents Limited Design Time Support to Understand or Reduce Interactive

Complexity− Existing analytical methods e.g. rate monotonic analysis, address individualaspects but skilled practitioners are required to employ these techniques• As a result we see limited application− Simulations are typical hand written and are difficult to keep synchronizedwith the design; or abstract away details that lead to hidden dependencies Present Cyber Physical Systems Rely on Human Ingenuity at Design Time

and Extensive System Testing to Manage Interactive Complexity− As a result, we experience long and costly development efforts that are expected to

encounter system accidents.


Application Research Initiative

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Application Specific Approaches

Cyber-Bio Interface

Critical Physical Infrastructure

Tele-Interaction

Smart Transportation

System Infrastructure


April 18, 2023 WECON 2011 32

Cyber Bio Interface

The four questions for cyber-bio systems

1. Can biological systems operationalize certain aspects of cyber systems so that we can understand and design advanced biological systems?

2. Can biological systems operationalize certain aspects of cyber systems so that we can understand and design advanced cyber systems?

3. Can cyber systems operationalize certain aspects of biological systems so that we can understand and design advanced biological systems?

4. Can cyber systems operationalize certain aspects of biological systems so that we can understand and design advanced cyber systems?


Harvey Rubin, MD, PhD University of Pennsylvania, NSF, Austin, October 17, 2006


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Cyber Bio Interface

1. Can biological systems operationalize certain aspects of cyber systems so that we can understand and design advanced biological systems?

Answer : YES

Up to the level of tissues and cultures, this is predominantly in the world of synthetic biology.

1918 Flu Epidemic : Complete genome sequenced in 2005




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2. Can biological systems operationalize certain aspects of cyber systems so that we can understand and design advanced cyber systems?

Answer : No

While DNA computation has been proved possible, time for the ‘gate’ to operate has been in the order of several seconds

Cyber Bio InterfaceApplication Specific Approaches



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Cyber Bio Interface

Physical Limitations of DNA Computing Hamiltonian path problem

25 nodes….. 1 kilogram of DNA needed

70 nodes….. 1000 kilograms of DNA needed !




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Cyber Bio Interface

3. Can cyber systems operationalize certain aspects of biological systems so that we can understand and design advanced biological systems?

Answer: Yes

Nano-bio Medical devices Lab on a chip NSF workshop on high confidence

medical devices and software systems last year

Subject of Tele-Physical services and applications working group at NSF Workshop

> $3 billion invested already !

2007 NSTI Nanotechnology Conference and Trade Show – May 2007 - Santa Clara


Harvey Rubin, MD, PhD, University of Pennsylvania, NSF, Austin, October 17, 2006


April 18, 2023 WECON 2011 37

Cyber Bio Interface

4. Can cyber systems operationalize certain aspects of biological systems so that we can understand and design advanced cyber systems?

Answer : Yes !

Has been happening all the time:




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Cyber Bio Interface

examples abound (from molecular level to societal level) Persistence in bacteria

hedge strategy against attack Cellular metabolism : metabolic flux models

supply chain Swarm behavior

Autonomous mobile robots Inverse problem

Markets Data aggregation Event prediction




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Critical Physical Infrastructure

What is Critical Physical Infrastructure? CPS Infrastructure: Interconnected

systems with seamless interaction between computing and physical systems.


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Critical Physical Infrastructure Current Challenges What to do with data collected by the CPS - for e.g.

(oil pipeline inspections) Translate / Interpret data and arrive at a decision Communicate with the people in charge.

Develop large scale models of the physical world Being done in SCADA for prediction SCADA - Supervisory Control And Data Acquisition :

(called Human Machine Interface in Europe) Large Scale Distributed Measurement (and Control) System

We need data on abnormal conditions CPS are subject to massive (cascading) failures. Power Grid, Air Traffic, Automotive, Data Centers

How do we handle unpredictable component interactions ?


April 18, 2023 WECON 2011 41

Tele-Interaction

Remote/Distributed = Tele Perception Action Interaction



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Scenarios Tele-Interaction Application First responder applications

Dangerous environments, under water exploration, fire fighting

Tele-health, tele-services for aging population (assisted living) Collaborative dancing Physiotherapy between a doctor and patient

Training environment for training medical personal for tele-surgery Tele-immersion inside of the body

Network of robots and sensors that work in a cyber-physical spaces with a remote human in the loop to accomplish dangerous, unpleasant, or super-human activities

Factory automation and reconfiguration



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Tele Interaction - Unmet Needs Latency-sensitive Internet Display technology and the overall I/O

technology Haptic technology needs higher time

resolution, many sensors and display to emulate whole hand sensing and actuation

Interactive human-machine interfaces are limited

Managing Complexity Networked self-organization Trust, Security and self-certifying software


April 18, 2023 WECON 2011 44

Tele-Interaction Challenges

How do we achieve being in remote space feeling in remote space effecting remote space

Synchronization in multi-modal environments; Trust (reliability, safety, privacy, …) Robust and fault tolerant systems Achievement of autonomy and semi-autonomy Reusable user interfaces


April 18, 2023 WECON 2011 45

Smart Transportation Challenges

Basic Goal : move people and goods Safely and reliably Efficiently (min resources, no environmental

damage) Quickly Desirably (passenger’s experience should be fun)

“Smart” ? Use CPS to improve / facilitate all of the above Use the transportation system to provide traffic,

GIS, terrain data



April 18, 2023 WECON 2011 46

CPS Enabled Automobile Trend

Goals– Enhance safety of vehicle and occupants during various driving

maneuvers; avoid crashes– Enhance convenience of driver of the vehicle• Trend is shift from warning-only or information-only systems (e.g.,collision warning systems) to systems that actively control accelerationand braking (longitudinal motion) and steering (lateral motion), leading

to semi-autonomous and eventually fully autonomous vehicle operation

• Examples:– Forward collision warning– Adaptive Cruise Control (ACC) + extensions – Curve speed control– Side blind zone alert– Lane change assist– Lane keeping / lane centering control– Cross traffic collision avoidance– Parking assist


April 18, 2023 WECON 2011 47

Research Needs for Auto Industries

360°sensing via vision, radar, sonar, and sensor fusion for higher levelsituational awareness• Robust requirements: how should the vehicle behave in anticipation ofevery possible real-world driving scenario

• Driver experience, skill level, and mental state (e.g., drowsiness, inattentiveness)

• Vehicle state of health / maintenance / repair• External environmental factors (weather conditions, road conditions,

traffic conditions)• Learning, adaptable, reconfigurable run-time systems

• Fault tolerant architectures– Hardware and Software fault tolerance (USCAR project on run-time

architecture)• Distributed diagnosis/prognosis• Human Vehicle Interface– Sensing and learning the driver’s skills, habits, and current condition

(attention, drowsiness, impairment)– Driver workload management


April 18, 2023 WECON 2011 48

System Infrastructure

Problem Statement: Coupling interface between computers

and the physical world. Methods and models for validation Co-development

Self Configurability of systems and system parameters within requirements

Self description capable , self aware systems Education


April 18, 2023 WECON 2011 49

System Infrastructure -Challenges

Dealing with time, distributed architecture, space, scale

Dealing with the hybrid nature of CPS Security ?

Adaptive OS / Self regeneration capability

Engineering Education Issues



April 18, 2023 WECON 2011 50

Summary

CPS is the hype of next decades! Involves multi-disciplinary research

High confidence SW CPS has the potential to change the

way people interact with their surroundings

applications in the future for CPS are limited only by human imagination

Affordability and ease of use will drive adoption


Cyber-Physical Systems: Issues and Challenges Rabi N. Mahapatra Texas A&M University (Adopted from...

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