1. Cyber-Physical Systems: Issues and Challenges
Rabi N. Mahapatra
Texas A&M University
(Adopted from NSF Workshops)
September 18, 2018
WECON 2011

2. Overview What are Cyber-Physical Systems?
Emerging Context: Applications, technical & Economic
Issues & Challenges
Application Specific Research Identification
Summary
September 18, 2018
WECON 2011

3. 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
September 18, 2018
WECON 2011

4. Economic Context: US & EU Competitiveness
American Competitiveness Initiative announced:
EU Framework Programme 7, European Research Council, and related actions
• ARTEMIS
– Backbone of European Research Area for Embedded Systems,
• 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
September 18, 2018
WECON 2011

5. 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 glucose
monitors, infusion pumps (insulin), accelerometers
(falling, immobility), wearable networks (gait
analysis), …
• Operating Room of the Future (Goldman)
– Closed loop monitoring and control; multiple
treatment stations, plug and play devices; robotic
microsurgery (remotely guided?)
– System coordination challenge
• Progress in bioinformatics: gene, protein
expression; systems biology; disease dynamics,
control mechanisms
Images thanks to Dr. Julian Goldman, Dr. Fred Pearce
September 18, 2018
WECON 2011

6. Example: Electric Power Grid
Current picture:
– Equipment protection devices trip
locally, reactively
– Cascading failure: August (US/Canada)
and October (Europe), 2003
Better future?
– Real-time cooperative control of
protection 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
September 18, 2018
WECON 2011

7. Example of a CPS concept (fiction)
Application Example
Example of a CPS concept (fiction)
“Weebo” has a personality, helps the absent minded professor in his duties.
(she) can hover at eye level,
Can navigate around the professor’s home on her own.
Can make decision and can carry on an intelligent conversation with the professor
(has feelings !)
No longer fiction.. Its becoming reality
Concept : Personal Assistant
Weebo – from the movie ‘Flubber’
Flubber © Disney Motion Pictures 1997
September 18, 2018
WECON 2011

8. Fiction becomes reality
Application Example
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
Houston Space Center has a video on this concept.
Personal Satellite Assistant © NASA Ames Research Center
September 18, 2018
WECON 2011

9. 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.
Prototype
Artist’s concept of a PSA assisting an astronaut
September 18, 2018
WECON 2011
Images © NASA Ames Research Center

10. 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.
September 18, 2018
WECON 2011

11. Produce significant impact on society and national competitiveness.
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.
September 18, 2018
WECON 2011

12. Industry Sectors To Benefit
Automobiles
Industrial Automation
Energy
Defense and Space
Intelligent Homes and
Health/Medical Equipment
Other Sectors to benefit:
Telecommunications
Consumer Electronics
September 18, 2018
WECON 2011

13. 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.
September 18, 2018
WECON 2011

14. Issues & Challenges
September 18, 2018
WECON 2011

15. 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.
September 18, 2018
WECON 2011

16. From IT Abstractions to “Hardware/Software”
From CAD schematics to chips
From DNA
‘programs’ to
living organisms
ISR-SEIL, Copyright © 2006
September 18, 2018
WECON 2011

17. From IT Abstractions to “HW/SW”
From algorithms and schematics to radios
Embedded systems design tools
Picoradio
UAV Controller
INS
R-50 Hovering
GPS Antenna
No difference between HW and SW
HW/SW co-design,, software radios
GPS Card
ISR-SEIL, Copyright © 2006
September 18, 2018
WECON 2011

18. 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 get
smaller what is cyber
and what is physical
gets fuzzier
Communicating minds
From material layer
controlled by cyber layer
to “programmable matter”
Swarm intelligence
True convergence of
Control, communication
computing
ISR-SEIL, Copyright © 2006
September 18, 2018
WECON 2011

19. Areas of Challenge Communication between the components
Data Storage & Retrieval
Data Security
Scalability
Management of the CPS devices
User Interfaces
Safety
September 18, 2018
WECON 2011

20. Communication Large amounts of data transfer will be required
Challenge > Communication
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.
Large amounts of data transfer – will it be ‘bursty’ or continuous or some kind of new data flow pattern ?
September 18, 2018
WECON 2011
Image © davisdrive.wcpss.net

21. Communication-Security
Challenge > Communication
Communication-Security
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 ?
September 18, 2018
WECON 2011
NSF Workshop, Austin, October 17, 2006

22. Data Storage & Retrieval
Challenge > Data Storage & Retrieval
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.
Distributed storage is the way to go in the future, allows for more network reliability.
September 18, 2018
WECON 2011
Image © NeoScale Systems Inc

23. Scalability CPS will be a global, open & extensible platform
Challenge > Scalability
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 ?
These are some questions which remain to be answered.
(Planetwide – as will be seen from the application specific challenges – smart transportation, bio app )
If you are monitoring air pollution across the world
September 18, 2018
WECON 2011

24. 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 ©
September 18, 2018
WECON 2011

25. Safety of Cyber-Physical Systems
September 18, 2018
WECON 2011

26. 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 mode
connections, limited system understanding, reliance
of human expertise, many control parameters
Systems with high interactive complexity
possess numerous hidden interactions
that can lead to systems accidents
− Nuclear Power Plants
− Chemical Plants
− Software Systems
System Accident: The halting of system
operations due to damage or failure of
multiple subsystems that arises from the
unanticipated interactions of multiple
failures
September 18, 2018
WECON 2011

27. Cyber Physical System Accidents
USS Yorktown (
navy.html )
− Suffered a systems failure when bad data was fed into its
computers 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 propulsion
system to fail
− ”We are putting equipment in the engine room that we
cannot maintain and, when it fails, results in a critical
failure," DiGiorgio said. It took two days of pier-side
maintenance to fix the problem.
September 18, 2018
WECON 2011

28. Accident due to SW Bug Ariane Five(
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)
September 18, 2018
WECON 2011

29. 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 unexpected
function, performance, or accidents
Limited Design Time Support to Understand or Reduce Interactive Complexity
− Existing analytical methods e.g. rate monotonic analysis, address individual
aspects 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 synchronized
with 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.
September 18, 2018
WECON 2011

30. Application Research Initiative
September 18, 2018
WECON 2011

31. Application Specific Approaches
Cyber-Bio Interface
Critical Physical Infrastructure
Tele-Interaction
Smart Transportation
System Infrastructure
Each of these Applications – has a separate presentation to themselves, so this is a condensed version of them
Cyber Bio Interface is the most promising field here.
Followed by Critical Physical Infrastructure and Smart Transportation.
September 18, 2018
WECON 2011

32. The four questions for cyber-bio systems
Application Specific Approaches
Cyber Bio Interface
The four questions for cyber-bio systems
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
September 18, 2018
WECON 2011

33. Application Specific Approaches
Cyber Bio Interface
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.
*advanced biological systems is a speculative word.
*We can currently go till the level of tissues and cultures
*Synthetic biology – artifical skin for burn victims, the robotic hand prosthesis,
*1918 Flu Epidemic : Complete genome sequenced in 2005
1918 Flu Epidemic : Complete genome sequenced in 2005
September 18, 2018
Harvey Rubin, MD, PhD University of Pennsylvania, NSF, Austin, October 17, 2006
WECON 2011

34. Application Specific Approaches
Cyber Bio Interface
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
Len Adelman DNA computation papers
he solved a seven-node instance of the Hamiltonian Graph problem, an NP-Complete problem.
Molecular Computation of Solutions to Combinatorial Problems",
journal = "Science", november "1994",
Harvey Rubin, MD, PhD University of Pennsylvania, NSF, Austin, October 17, 2006
September 18, 2018
WECON 2011

35. Cyber Bio Interface Physical Limitations of DNA Computing
Application Specific Approaches
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 !
Len Adelman DNA computation papers—highly parallel, solve NP problems
he solved a seven-node instance of the Hamiltonian Graph problem, an NP-Complete problem
author = "Leonard M. Adleman",
title = "Molecular Computation of Solutions to Combinatorial Problems",
journal = "Science", november "1994",
September 18, 2018
Harvey Rubin, MD, PhD University of Pennsylvania, NSF, Austin, October 17, 2006
WECON 2011

36. Application Specific Approaches
Cyber Bio Interface
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 !
Life Sciences & Medicine Bio-nano Materials & Tissues Bio Sensors & Diagnostics Biomarkers & Nanoparticles Cancer Nanotechnology Cellular & Molecular Dynamics
Drug Delivery & Therapeutics Imaging Nano Medicine Nanotech to Neurology
2007 NSTI Nanotechnology Conference and Trade Show – May Santa Clara
September 18, 2018
Harvey Rubin, MD, PhD, University of Pennsylvania, NSF, Austin, October 17, 2006
WECON 2011

37. Application Specific Approaches
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:
Harvey Rubin, MD, PhD, University of Pennsylvania, NSF, Austin, October 17, 2006
September 18, 2018
WECON 2011

38. Application Specific Approaches
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
Inverse problem – model parameters to be obtained from the model data.
The transformation from data to model parameters is a result of the interaction of a physical system such as the Earth
Harvey Rubin, MD, PhD, University of Pennsylvania, NSF, Austin, October 17, 2006
September 18, 2018
WECON 2011

39. Critical Physical Infrastructure
What is Critical Physical Infrastructure?
CPS Infrastructure: Interconnected systems with seamless interaction between computing and physical systems.
How is this different from traditional embedded computing ?
Embedded – is about the physical effects of computing
CPS – is about the scaling of systems of embedded systems (a field that we do not understand)
September 18, 2018
WECON 2011

40. 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 ?
CPS are subject to massive (cascading) failures.
Power Grid, Air Traffic, Automotive, Data Centers – CPS in each of these situations will have to respond differently.
Communication failures will have to be handled in a graceful degradation fashion.
September 18, 2018
WECON 2011

41. Tele-Interaction Remote/Distributed = Tele Perception Action
Attributes of tele-interaction
Encompasses:
Tele-services (e.g., human services for elderly)– Tele-immersion (e.g., Medical surgery and rehabilitation)– Tele-operation (e.g., hazardous operation)
– Tele-supervisory control (e.g., remote construction, traffic management)– Factory automation– Environmental monitoring
Dr. Mahapatra & Dr. Bettati participated in this “working group”
September 18, 2018
WECON 2011
NSF Workshop, Austin, October 17, 2006

42. 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
September 18, 2018
WECON 2011
NSF Workshop, Austin, October 17, 2006

43. 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
Haptic technology refers to technology which interfaces the user via the sense of touch by applying forces, vibrations and/or motions to the user.
It is an emerging technology that promises to have wide reaching applications.
Although haptic devices are capable of measuring bulk or reactive forces that is applied by the user it should not to be confused with touch or tactile sensors that measure the pressure or force excerted by the user to the interface.
September 18, 2018
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
Turing test for presence (human/physical object appearance)
Scalable and managed distributed infrastructure
Addressing of human/computer interaction and slave/environment interaction
September 18, 2018
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
passenger’s experience should be fun – should not induce motion sickness or other such ailments
transportation system could relay the real time data back to the HQ
September 18, 2018
WECON 2011
NSF Workshop, Austin, October 17, 2006

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 acceleration
and 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
September 18, 2018
WECON 2011

47. Research Needs for Auto Industries
360°sensing via vision, radar, sonar, and sensor fusion for higher level
situational awareness
• Robust requirements: how should the vehicle behave in anticipation of
every 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
September 18, 2018
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
September 18, 2018
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
September 18, 2018
WECON 2011
NSF Workshop, Austin, October 17, 2006

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
September 18, 2018
WECON 2011