R.A.C.E. Project Urbino 29-30 March 2012 ITIS “E. Mattei” to R.A.C.E. Leonardo Project –...
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R.A.C.E. Project Urbino 29-30 March 2012 ITIS “E. Mattei” to R.A.C.E. Leonardo Project – 03_29_2012 Urbino – IT - Massimo Zandri
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Transcript of R.A.C.E. Project Urbino 29-30 March 2012 ITIS “E. Mattei” to R.A.C.E. Leonardo Project –...
R.A.C.E. ProjectUrbino 29-30 March 2012
ITIS “E. Mattei” to R.A.C.E. Leonardo Project – 03_29_2012 Urbino – IT - Massimo Zandri
Some Features of DC motors
ITIS “E. Mattei” to R.A.C.E. Leonardo Project – 03_29_2012 Urbino – IT - Massimo Zandri
Different type of servomotor
• DC brushed motors
• AC brushless motors
• Step motors
ITIS “E. Mattei” to R.A.C.E. Leonardo Project – 03_29_2012 Urbino – IT - Massimo Zandri
DC Brushed motors
• Benefits: 1. max torque at 0 r.p.m.2. Easy to control shaft speed3. Easy and economical to produce
• Disadvantages1. Brushes consumption2. Collector consumption
ITIS “E. Mattei” to R.A.C.E. Leonardo Project – 03_29_2012 Urbino – IT - Massimo Zandri
AC Brushless motors
• Benefits: 1. Brushes non present2. Greater Electrically efficiency than DC motor3. Low weight
• Disadvantages1. Complex speed control2. More expensive than a DC motor of same power.
ITIS “E. Mattei” to R.A.C.E. Leonardo Project – 03_29_2012 Urbino – IT - Massimo Zandri
STEP motors
• Benefits: 1. Very fine adjustment of position also without feedback2. Higher torque also at 0 r.p.m.3. No gear box needed
• Disadvantages1. Low number of r.p.m.
ITIS “E. Mattei” to R.A.C.E. Leonardo Project – 03_29_2012 Urbino – IT - Massimo Zandri
A model for DC motor
• We can define a set of differential equations
ITIS “E. Mattei” to R.A.C.E. Leonardo Project – 03_29_2012 Urbino – IT - Massimo Zandri
A model for DC motor (2)• Ve = Re Ie + Le die (t)/dt
• Va = RaIa + La dia (t)/dt + f.e.m.
• If ie = const => f.e.m. = KeIeKa AND Va = RaIa + La dia (t)/dt + KeIeKa
• Appling Laplace transform we obtain:
•
• Let KeIeKa = Km and the mechanical equation to the shaft
ITIS “E. Mattei” to R.A.C.E. Leonardo Project – 03_29_2012 Urbino – IT - Massimo Zandri
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A model for DC motor (3)• We obtain a model with 2 poles in a feedback configuration
• If ie = const => f.e.m. = KeIeKa AND Va = RaIa + La dia (t)/dt + KeIeKa
• Appling Laplace transform we obtain:
•
• Let KeIeKa = Km and the mechanical equation to the shaft
ITIS “E. Mattei” to R.A.C.E. Leonardo Project – 03_29_2012 Urbino – IT - Massimo Zandri
)]()([1
sKIKsVsLR
I aeeaaa
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mtDtJ
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Thank you!
ITIS “E. Mattei” to R.A.C.E. Leonardo Project – 03_29_2012 Urbino – IT - Massimo Zandri
