Post on 30-May-2020
transcript
Actuators (1)
© 2013 Stephen R. Platt ME 461 1
H-Bridge Motor Drivers
B A
C D
ON OFF
ON OFF
Forward
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© 2013 Stephen R. Platt ME 461 2
H-Bridge Motor Drivers
B A
C D
OFF ON
OFF ON
Reverse
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© 2013 Stephen R. Platt ME 461 3
H-Bridge Motor Drivers
B A
C D
OFF OFF
ON ON
Brake
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© 2013 Stephen R. Platt ME 461 4
LMD18200 H-Bridge
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© 2013 Stephen R. Platt ME 461 5
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© 2013 Stephen R. Platt ME 461 6
PMDC Motors
stator
rotor brushes
commutator contacts
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© 2013 Stephen R. Platt ME 461 7
PMDC Motors • Simple Model
in EdIV L RI Kdt
ω= + +
• More Complete Model
TK Iτ =Coulomb Friction
Viscous Friction
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© 2013 Stephen R. Platt ME 461 8
PMDC Motors • More Complete Model
in EdIV L RI Kdt
ω= + +
( )T cK I J D D signυτ α ω ω= = + +
friction
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© 2013 Stephen R. Platt ME 461 9
PMDC Motors • DC Motor Specifications
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© 2013 Stephen R. Platt ME 461 10
Brushless DC Motors • Rotor with permanent magnets • Stator with windings • Essentially a DC motor turned inside out • Control electronics take the place of brushes and
commutators
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© 2013 Stephen R. Platt ME 461 11
Brushless DC Motors
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Stepper Motors • Essentially a brushless DC motor with many more stator
and rotor poles.
Phase ‘a’ energized
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© 2013 Stephen R. Platt ME 461 13
Stepper Motors • Full Step Motor
Phase ‘b’ energized
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© 2013 Stephen R. Platt ME 461 14
Stepper Motors • Half Step Motor
Phase ‘a’ energized
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© 2013 Stephen R. Platt ME 461 15
Stepper Motors • Half Step Motor
Phases ‘a’ and ‘b’ energized