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

Data flow in automated manufacturing

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

Current Manufacturing Automation Increased requirements on latency and communication

Challenges with Real-time Data - GM

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

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

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

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

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?

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?

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

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

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

Network End-to-End Performance Cost PB 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

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?

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

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

Thank you for your attention! Questions?