Servo Motor Control

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Servo Motor Control

• Basic computer control of motor position and
  velocity

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Watch the motor

• LP loop
• DI 1.5 distance 1.5
• GO start move
• TD 1 delay 1
• DI -1.5 distance -1.5
• GO start move
• TD 2 delay 2
• EB end block
• EN end program

• POWERUP
• AC .5 accel .5
• VE 1.5 velocity 1.5
• Note accelerates to velocity of 1.5,
• decelerates to stop

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Position vs. time
Velocity vs. time 1 Cos( t )
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How do you judge position?

• Encoder

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Direction?
Encoders are typically 5000 10000
pulse/revolution
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How do you judge speed (velocity)?

• Attach motor shaft to small generator
• Use the motor to generate electricity
• Faster more
• Called a Tachometer

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servo motor control

• 1.0 1.25 1.5 1.75

0 360 is 1 ms

• 1.0 1.25 1.5 1.75

• 1.0 1.25 1.5 1.75

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Same distance, half speed. PWM pulse
width modulation
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time (t1)