1. Latency and Communication Challenges in Automated Manufacturing
Kira Barton Department of Mechanical Engineering University of Michigan
November 3rd, 2016

2. Data flow in automated manufacturing

3. Current Manufacturing Automation
Digital Manufacturing – new enabling technologies:
Cloud computing
Internet of things
MTConnect
Virtualization
Service-oriented architectures
Advanced computing technologies

4. Current Manufacturing Automation
Increased requirements on latency and communication

5. Challenges with Real-time Data - GM

6. Challenges with Real-time Data - GM
Sensing Real-time
Data
Inventory
People
Machines
What to collect ?
Smart Sensing?

7. Challenges with Real-time Data - GM
What to collect ?
Smart Sensing?
Main Server
Internet
Plant Monitoring & Control
What/When/Where to transfer?
How to provide feedback?
Sensing Real-time
Data
Inventory
People
Machines

8. Challenges with Real-time Data - GM
Remote Monitoring & Control
What to monitor?
How to analyze?
How to control?
Analysis
What to collect?
Smart Sensing?
Main Server
Internet
Plant Monitoring & Control
What/When/Where to transfer?
How to provide feedback?
Sensing Real-time
Inventory
People
Machines

9. Challenges with Real-time Data - GM
Product & Mfg.
Engineering
PLANNING
DESIGN
Maintenance
Anomaly detection
Learning
What to do with the information? Decision making?
Real-time
Data
Remote Monitoring & Control
What to monitor?
How to analyze?
How to control?
Analysis
What to collect?
Smart Sensing?
Main Server
Internet
Plant Monitoring & Control
What/When/Where to transfer?
How to provide feedback?
Sensing Real-time
Inventory
People
Machines

10. Challenges with Real-time Data - GM
Product & Mfg.
Engineering
PLANNING
DESIGN
Maintenance
Anomaly detection
Learning
What to do with the information? Decision making?
Real-time
Data
Remote Monitoring & Control
What to monitor?
How to analyze?
How to control?
Analysis
What to collect?
Smart Sensing?
Main Server
Internet
Plant Monitoring & Control
What/When/Where to transfer?
How to provide feedback?
Sensing Real-time
Inventory
People
Machines
What to Communicate and how?

11. Network requirements to be addressed
Control: high fidelity for decision making
Diagnostics: data storage, analytics, learning
Safety: fast and accurate response times
1. Which sensors to include at each level – Machine, cell, system, factory
How to convert and transfer data between enterprise levels?
What are communication needs and latency impacts?

12. Network Partitioning for Control, Diagnostics and Safety on Ethernet
Ethernet I/O functionality domains
Control: Medium data volumes, high determinism
Diagnostics: High data volumes, high speeds, low determinism
Safety: Small data volumes, very high determinism

13. Network Partitioning for Control, Diagnostics and Safety on Ethernet
Central Switch
System Switch
Control
Secure Cloud Infrastructure
Firewall
Machine level
Sensing
Control level

14. Network Partitioning for Control, Diagnostics and Safety on Ethernet
Central Switch
System Switch
Control
Secure Cloud Infrastructure
Firewall
Machine level
Sensing
Control level
Timing mismatch
Network congestion
Poor network provisioning
Noisy signals
Data loss

15. Network End-to-End Performance CostPB PA PC
Continuous Control A
Digital Control
Performance: Tracking Error
Worse
Better
Sampling Time
Larger
Smaller
Acceptable
Out of Control
Networked Control B C
Impact of sampling & additional delays
Network saturation inducing longer delays
Unacceptable
Ideal
Operating
Region
Impact of sampling

16. Issues driving network performance
Can I use TCP/IP versus EtherNet/IP or EtherCat?
Should I put safety, control and diagnostics on one, two or three networks?
Should I partition my networks at different levels?
What is the tradeoff cost of a decision?
Where is the delay and delay variability occurring?
What is the tradeoff complexity of a decision?
What is the performance cost of security or application level protocols ?
What are the industry defacto standards?

17. Current methods to address issues
Time synchronization algorithms
close to the production tasks
strict requirements on timing
need context to the data to align timing
Event-based control
mitigate logic errors
may result in time delays
Multiplex network scheduling
utilize alternative network interfaces for communication
transmit over path with smallest estimated delay
Improve software to address delays and communication issues

18. Automated manufacturing network requirements
Data transfer rate
Data transfer load
Impact of delays
Multi-plex capabilities
Low-level Control (CNC, robots, etc.)
1ms or faster
Medium
Critical (performance)
Typically no
High-level control (PLCs)
~10ms
Low
Diagnostics
Slow
High
Minimal
Yes
Safety
Fast
Critical
Potentially

19. Thank you for your attention!
Questions?