Georgia Institute of Technology | Marquette University | Milwaukee School of Engineering | North Carolina A&T State University | Purdue University | University of California, Merced | University of Illinois, Urbana-Champaign | University of
Minnesota | Vanderbilt University
Fluid Power Innovation & Research Conference
Minneapolis, MN | October 10 - 12, 2016
Case Studies in the Use of Customized
Feedback Control for Industrial Hydraulic
Motion Control Applications
Jacob Paso, Motion Product Development Manager Delta Computer Systems, Inc. Photo
FPIRC16 2
Motion
Controller
High-Performance
Motion Control
PositionSensor
Accumulator
High-Quality Proportional Valve
Reservoir
PumpPressure Sensors
FPIRC16 3
Closed-loop Control
FPIRC16 4
Typical configuration in industry
Direct Feedback – control to the value received from feedback device.
Motion
Controller
Position Sensor
FPIRC16 5
Typical configuration in industryMotion control module –performs closed loop motioninside module
Position Sensor
PLC
PLC – sends profilepath to motion module
FPIRC16 6
Direct Feedback – control to the value received from feedback device.
Motion
Controller
Position Sensor
Motion control module –performs closed loop motioninside module
Position Sensor
PLC
PLC – sends profilepath to motion module
Not flexible: Use only dedicated
feedback for control
FPIRC16 7
Motion
Controller
Custom Feedback:
Anything you can imagine!
+ - / √
If then else
sin 𝑥
1 0.996
2 2.002
3 3.012
4 3.997
FPIRC16 8
Applications:
Switching Feedback On-The-Fly
Feedback Linearization
Control to Sum, Average, Difference,
etc.Redundant Feedback
Custom Feedback
Position, Velocity,Pressure, Force, etc.
FPIRC16 9
Redundant Feedback
Motion
Controller
Motion
Controller
FPIRC16 10
Feedback Linearization
• Correct for small errors
• Geometric conversionFeedback
Desired measurement
FPIRC16 11
Switching Feedback On-the-Fly
Switch between multiple sensors over the desired measurement range for maximum measurement resolution in each range.
FPIRC16 12
Switching Feedback On-the-Fly
Example:0-10,000 psi testing system
At 100 psi, this test would give only 10% accuracy.
= .1% accuracy .1% of 10000 psi = ± 10 psi
FPIRC16 13
Switching Feedback On-the-Fly
Use multiple sensors for maximum accuracy over the entire range
Greater testing accuracy achieved by smoothly switching between sensors on-the-fly.
= 0-500 psi, .1% accuracy ± 0.5 psi
= 0-5000 psi, .1% accuracy ± 5 psi
= 0-1000 psi, .1% accuracy ± 10 psi
FPIRC16 14
Control to Average, Difference,
Sum, etc.Example: Pulp refining gap control
Sensor 2Sensor 1
Gap = Sensor 2 – Sensor 1
FPIRC16 15
Electronic Platen Control
Custom Feedback + Cascaded Loop
Sum the cylinder forces together
to control total force of platen.
Results in a lightweight platen
FPIRC16 16
Electronic Platen Control
Custom Feedback + Cascaded Loop
Command Force
Parallel Inner Position Loops
⁞ ⁞
Position 1
Position N
Forces
Outer Loop
FPIRC16 17
Industrial Application:
Split-platen press with independent or synchronized platens
• Lightweight platen
• Form 1 long piece or 2 short pieces
FPIRC16 18
Other examples
• Power control (Pressure x Flow)
• Multiple load cells
Future• Limited by your imagination and sensor
technology