1 of 22 Measurement And Control Of Slip In a Continuously Variable Transmission B. Bonsen, T.W.G.L. Klaassen, K.G.O. van de Meerakker M. Steinbuch, P.A. Veenhuizen
Dec 21, 2015
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Measurement And Control Of Slip In a Continuously Variable Transmission
B. Bonsen,
T.W.G.L. Klaassen, K.G.O. van de Meerakker
M. Steinbuch, P.A. Veenhuizen
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CVT• Infinite number of ratios within a range
• Shifting while engaged
• Optimal use of IC engine
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CVT
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Slip
• Friction drive
• Slip between belt and pulley
• Wear
• Clamping force
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Efficiency
• Actuation losses
• Friction in Belt
• Bearing losses
• Lubrication
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Project goals
• Optimize CVT transmission efficiency by:
– using alternative actuation system
– lowering clamping force
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Lowering clamping force
• Advantage:– Less friction losses in the belt– Less actuation power – Less friction in the bearings– More torque on the wheels
• Disadvantage:– Increased risk of damage due to slip
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Measurement of slip
• Definition of slip
• Measurement of
• Calculation of
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Testrig
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Slip & Efficiency
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Slip & Friction
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Linearizing
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Variator model
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Nonlinear model
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Linearized model
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Eigenfrequencies
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Control
• Clamping force
• Ratio
• Speed
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Slip feedback
Fp
s
rg
re f+
-
Td
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Clamping force
• Safety
• Actuation bandwidth
• Slip measurement
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Stability using slip feedback
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Experimental Results
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Conclusions
• Stable control of slip
• Robustness for torque peaks up to 30Nm
• Lower clamping force (-30%)
• Higher variator efficiency (+4%)