eml 2023 – motor control
DESCRIPTION
EML 2023 – Motor Control. Lecture 2 – Motor. Let’s answer 3 questions. How is the motor held in place and how is it connected to the shaft that it is to rotate? How does the encoder work and how is it physically connected to the motor? How do the DAQ and motor driver work?. - PowerPoint PPT PresentationTRANSCRIPT
EML 2023 – Motor Control
Lecture 2 – Motor
EML 2023Department of Mechanical and Aerospace Engineering 2
Let’s answer 3 questions.
1. How is the motor held in place and how is it connected to the shaft that it is to rotate?
2. How does the encoder work and how is it physically connected to the motor?
3. How do the DAQ and motor driver work?
Motor Driver
desired position current
Computer and DAQ
Motor
analog speed signal
digital direction signal
Encoder
sensed actual position
EML 2023Department of Mechanical and Aerospace Engineering
DC Motor
• a typical DC motor can rotate at a top speed of 2600 rpm (43⅓ rev/sec)
• gearing is used which slows the speed of the output shaft, but increases the torque
• gear train• worm gear drive• epicyclic gear train
3
worm gear drive4
epicyclic gear train
gear train
EML 2023Department of Mechanical and Aerospace Engineering 5
Typical Speed vs. Torque Curve
Rotational Speed, rad/sec
Torq
ue,
lb-f
tStall Torque
No-load Speed
Optimum operating range
Design tip: DC motors usually operator at 10-30% of their stall torque. Motors that are subjected continuously to higher loads are more prone to mechanical failure or heat-related degradation.
EML 2023Department of Mechanical and Aerospace Engineering
Buehler DC Motor
6
10 mm
6
21 mmM4 – 0.7 mm threads
EML 2023Department of Mechanical and Aerospace Engineering
Denso DC Motor
7
EML 2023Department of Mechanical and Aerospace Engineering
How does the computer control the motor?
control the current (via the voltage)
8
EML 2023Department of Mechanical and Aerospace Engineering
Denso DC Motor
how is the motor connected to
ground?
how is the motor connected to the steering shaft?
9
EML 2023Department of Mechanical and Aerospace Engineering 10
Connecting the Motor to Ground
M6 – 1mm pitch
#6 - 32
Denso Buehler
EML 2023Department of Mechanical and Aerospace Engineering
Denso DC Motor
13
EML 2023Department of Mechanical and Aerospace Engineering 14
Buehler DC Motor
EML 2023Department of Mechanical and Aerospace Engineering 15
Let’s answer 3 questions.
1. How is the motor held in place and how is it connected to the shaft that it is to rotate?
2. How does the encoder work and how is it physically connected to the motor?
3. How do the DAQ and motor driver work?
Motor Driver
desired position current
Computer and DAQ
Motor
analog speed signal
digital direction signal
Encoder
sensed actual position