1. March 29, 2012IFAC Conference on Advances in PID Control1 PID APPROACH & ISSUES IN SERIES CONTROL SYSTEMS FOR MACHINE AUTOMATION Ing. Adriano Chinello Technical Director Automation Division Gefran S.p.A.

2. General Targets for Series Control Systems 2March 29, 2012IFAC Conference on Advances in PID Control  Standard PLC application development (IEC 61131-3, PLCopen)  High-value PLC software libraries: easy, complete, time-saving, …  Cost – optimized hardware architecture  Respect of target control specifications among many different machines and over a wide range of operating conditions Reference applications:  full-electric injection moulding machine (FE IMM)  Hydraulic injection moulding machine (HY IMM)

3. Specific Targets for IMM Control Systems 3March 29, 2012IFAC Conference on Advances in PID Control  Precise, repeatable and smooth changes between different control loops on single motion axes (position – speed – torque – mould pressure)  Electronic Noise Filtering / Tolerance (high power and inductive loads, poor cabling and shielding, …)  Compresence of very different processes: - Electric Motion control(cyclic + events)0.1 ÷ 1 ms - Hydraulic Motion control(cyclic + events)1 ÷ 5 ms - I/O (cyclic) 5 ÷ 20 ms - Thermoregulation (cyclic)50 ÷ 100 ms - HMI (events)> 100 ms - Supervisoring, Statistics, etc… (cyclic + events) low priority

4. PID Distribution in a FE IMM Architecture 4March 29, 2012IFAC Conference on Advances in PID Control Modbus / CANopen I/O real-time control loops Motion high- level control HMI task PLC / SPC / aux tasks Monitoring / data collection Analog Input Current Torque Speed Loop Position / AI Loop Speed / Torque Ref Optical internal link Power high- level control GDnet / CANopen Power / Thermo Loop Remote I/O Servo rack Panel PC Power Controller Pressure Sensor

5. Panel PC - Fieldbus Performance and Cost 5March 29, 2012IFAC Conference on Advances in PID Control cost www.cpubenchmark.net PID decentralisation allows Panel PC and fieldbus downsizing

6. PLC Motion Application Library 6March 29, 2012IFAC Conference on Advances in PID Control  Standard PLCopen  Only one software application for the whole machine  High-level programming, fieldbus and hardware independent  Standard Function Blocks with add-on (more flexibility)  Special Function Blocks with interfaces in line with the standard

7. Example: Injection Axis Control 7March 29, 2012IFAC Conference on Advances in PID Control  Easy to develop, with a series of Function Blocks in blending  Switchover on position, pressure, …  Control phases preloaded into the drive

8. PID Open Issues 8March 29, 2012IFAC Conference on Advances in PID Control  Smooth control switch vs time reactivity  Noise rejection vs time reactivity  Robust tuning procedures for reliability in series production: possibly one single tuning (or tuning procedure) for many machines and many different moulds for each machine  PID modularization and packaging into PLC software libraries, with both “simple entry level” and “complex advanced” user interface