EMA Technology Overview. ElectroMagnetic Actuator – EMA4K Peak Force = 19kN Peak Vel = 4m/sec...
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Transcript of EMA Technology Overview. ElectroMagnetic Actuator – EMA4K Peak Force = 19kN Peak Vel = 4m/sec...
EMA Technology Overview
ElectroMagnetic Actuator – EMA4K
• Peak Force = 19kN• Peak Vel = 4m/sec• Typical Damper Pk
Performance: 10kN @ 4m/sec
• Freq response up to 300Hz
• 200mm stroke• All Electric Motion• Also avail in 1K, 2K, 6K
configurations
Electromagnetic Actuator Fundamentals•U-Channel Brushless Linear Servo Motor
•Consists of a non-contacting forcer coil and a U-channel rare earth (Neodymium) magnet track
•Ironless forcer means there are no attractive forces and no disturbance forces generated between forcer and magnet track
•Ironless forcer has low mass resulting in high acceleration forces
•Three phase coil winding with sinusoidal brushless commutation
•U-Channel design reduces magnetic flux leakage
•Non-contact design supported by standard bearings to handle off-axis loading
Electromagnetic Technology – Where Used
• Assembly• Automotive• Data Storage• Electronic
Manufacturing• Machine Tool• Medical• Military/Aerospace
• Fiber Optics• Photovoltaics• Packaging• Engineered
Systems• Test & Inspection
Electromagnetic Actuator (EMA)Major Components
U-Channel Rare Earth Magnets
Optical Encoder Read head with 1um resolution
Forcer block attached to 3-phase forcer coils on each side (inside U-channel magnets)
Lower T-rail bearing support – 1 each side
Drylin actuator shaft bearing with replaceable inserts
End of Travel Limit Switches
U-Channel Magnet Assembly bolted to column supports both sides
Actuator motion generated here
EMA Comparisons – Damper Testing
Typical shock absorber performance as obtained from published literature
EMA Comparisons – General Performance
0.1
1
10
100
1000
1 10 100 1000
Dis
pla
cem
ent m
m (P
k-P
k)
Frequency (Hz)
Actuator Performance Comparison
Hyd HS EMA4K
Estimates based on the following assumptions:
• 2500kg GVW, 40kg unsprung, 650kg sprung mass, 6N/mm/sec viscous loading, 50N/mm spring load.
• Hyd HS = Typical hydraulic actuator with hydrostatic bearings, dual 50l/min servovalves, 200l/min 210 bar hydraulic supply
EMA Comparisons – General PerformanceDisplacement (Pk-Pk)
Freq(Hz) Hyd HS EMA4K
1 150 177
2 150 177
3 143.5 177
5 86.22 161
7 61.33 113
10 42.67 76
20 19.76 26.3
30 11.16 12.5
50 4.6 4.68
70 -- 2.41
150 -- 0.53
200 -- 0.26
*Peak Acceleration
Hyd HS EMA4K
23.14 24.25
* = peak acceleration based on unsprung mass of 40kg, wheelpan 20kg, and mass
of actuator
Actuator Mass
Hyd HS EMA4K
25.56kg 19kg
Estimates based on the following assumptions:
• 2500GVW, 40kg unsprung, 650kg sprung mass, 6N/mm/sec viscous loading, 50N/mm spring load.
• Hyd HS = Typical hydraulic actuator with hydrostatic bearings, dual 60l/min servovalves, 200l/min 210 bar hydraulic supply
EMA2K Performance – Road Data
Plot of Track Data Command and Feedback Profiles – Direct file Playback(No transfer function compensation required)
EMA2K Performance – Road Data
Zoom In on portion of Command AND Feedback Track Data (there are 2 plots)
EMA2K Performance – Road Data
Plot of Error throughout Entire Track File (Command – Feedback) RMS Error less than 0.001” (0.025mm)
EMA2K Performance – Road Data
Plot of Actual Forces Achieved during dynamic Track Data Playback on EMA2K
EMA2K Performance – Road Data
Zoom Plot of Dynamic Force - Track Data
EMA Benefits Summary Higher performance / frequency response due to:
No oil column resonance Lower actuator mass Lower friction (no seals) Tighter closed loop control
Direct file playback often 10X better than hydraulic system with
transfer function compensation! Independent of operating temperature
No oil viscosity variables to affect control loop Independent of waveform content
Can accurately run low velocity/low force and high velocity/high
force without changeover from 2stage to 3stage, etc Independent of accumulator charging/discharging cycles
EMA Benefits Summary Less Maintenance and Downtime
No seals, accumulators, servovalves, filtration, oil contamination DryLin bearings only contact points – easily replaceable No system degradation due to component wear (pumps, valves,
etc) Modular design and less components makes troubleshooting
easier
Lower Operating Costs Increased efficiency over servohydraulics means annual
electrical operating costs are 30% of comparable hydraulic systems
No filters, accumulators, servovalves, seals, hoses, pumps to repair/replace
Service and Support fees a fraction of major hydraulic competitors!
The new leader in dynamic testing