rise poster_final
TRANSCRIPT
Ultra-precision scanning stages• Applications
o Used in advanced manufacturing equipment such as wafer
scanners, and high-resolution 3D printers
• Two main problems of step motion [1]
o The stages are subject to large inertial load due to
acceleration
I. Stage base vibration
II. Motor heating
• Design goals
o Reduce the base vibration by 50%
o Reduce the motor heating by 50%
o No compromise on stage throughput and ground vibration
transmissibility during manufacturing
MOTIVATION
Bowen Zeng
[email protected]: Deokkyun Yoon and Prof. Chinedum Okwudire
Motor Heating• 8.3 J/step 1.7 J/step (80% reduction)
• Thermal errors mitigated with reduced heat generation
Energy harvested• 1.3 J/step (12% total energy consumption recovered)
Base Vibration• 1300 𝜇m, RMS 2.6 𝜇m, RMS (99% reduction)
Since the energy recovery rate is low, design 3 is the best
Future work• Optimize energy harvest rate of RSA, and investigate coupling
design between coarse and fine stages and control methods
CONCLUSION AND FUTURE WORK
[1] Yoon D, Okwudire CE. Magnet assisted stage for vibration and heat reduction in wafer scanning.
CIRP Annals - Manufacturing Technology (2015), http://dx.doi.org/10.1016/j.cirp.2015.04.105
[2] Li, Zhongjie, George Luhrs, Liangjun Lin, and Yi-xian Qin. "Electromagnetic Energy-
Harvesting Shock Absorbers: Design, Modeling, and Road Tests." IEEE TRANSACTIONS ON
VEHICULAR TECHNOLOGY 62.3 (2013): 1065-074. Engineering Village. Web. 13 Apr. 2016.
[3] Toma, Adrian. "RELUCTANCE VS LORENTZ." MIKRONIEK 2013: 21-26. Print.
REFERENCES
SIMULATION RESULTS
Heat and Vibration Reduction of
Ultra-Precision Stages During Step Motions
Design 3: Coarse and fine stage configuration
Design 4: Coarse and fine stage configuration with
regenerative shock absorber (RSA)
Performance metrics of 4 designs
BASELINE
• Isolated base
connected to
machine ground
• Base mounted
step stage (linear
motor)
PROPOSED DESIGNS
Design 1: Ground mounted linear motor stator
Design 2: Linear switched reluctance motor (LSRM)
• Hybrid of a
Lorentz Linear
motor (fine stage)
and a LSRM
(coarse stage)
• LSRM ONLY
turns on during
coarse positioning
• Machine ground
mounted linear
motor stator
• Motor reaction
force filtered by
machine ground
• Hybrid of a rotary
motor (coarse
stage), and a linear
motor (fine stage)
• Machine ground
mounted coarse
stage
• FLM=0, and km=0
during coarse
positioning; kc=0
during fine
positioning
• Install regenerative
shock absorber
(RSA)
• Partially recover
kinetic energy of
moving stage
• Cr=0 during braking
of coarse stage and
fine positioning
Motor Heating
[J/step]
Base Vibration
[𝜇m, RMS]
Energy Harvested
[J/step]
Key
Equations
Baseline/Design 1:
WLM=නFMKM
2
dt
Design 2:
I=
2g+C2FC1
n[3]
W=න I2Reff dt
Design 3/4:
TM=a2πS.F.
𝜂lsmls2
4π2+JM
WRM=නTMKM
2
dt
G s =C(sI−A)−1B
Design 4:
ceff≈KTKE𝜂
Rtotalls2
[2]
Ere=ceffන ሶyg− ሶyc2dt
Baseline 8.3 1300 -
Design 1 8.3 0.63 -
Design 2 2.0 0.63 -
Design 3 1.7 2.6 -
Design 4 0.93 1.4 1.3
• Base Vibration (frequency domain)
o Ground vibration transmissibility o Motor induced vibration FRF
• Energy harvested
• Base Vibration (time domain)• Assumed profiles
• Motor heating