ATAVRMC310 Atmel, ATAVRMC310 Datasheet - Page 12

• Manufacturer Part Number: ATAVRMC310
• Description: BOARD EVAL MOTOR CTRL W/MEGA32M1
• Manufacturer: Atmel
• Series: AVR®r

Specifications of ATAVRMC310

• Main Purpose: Power Management, Motor Control
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: ATmega32M1
• Primary Attributes: 3-Ph BLDC, Brushed DC, Stepper Motor- Controller Board
• Secondary Attributes: Requires ATAVRMC300 Power Driver Board
• Processor To Be Evaluated: ATmega32M1
• Data Bus Width: 8 bit
• Interface Type: RS-232, USB
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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AVR194
Figure 9. Regulation Loop
The speed loop consists in a speed regulation loop with the PID corrector.
We will further explain how to adjust the coefficients KP and KI. The KD coefficient is present in
the regulation loop but not used.
As previously shown, the KP coefficient is used to regulate the motor response time. First time
set KI and KD to ‘0’. Try different values of KP to get a correct motor response time.
•
•
Figure 10. Kp Tuning Example
KI parameter is used to cancel the static error. Leave the KP coefficient unchanged and set the
KI parameter.
•
•
mc_cmd_speed
If the response time is too slow, increase KP gain.
If the response time is quick, but motor speed is unstable, decrease KP gain.
If the error is still different from zero increase KI gain.
If the error is cancelled but oscillations appears, decrease KI gain.
160
140
120
100
80
60
40
20
1 : mc_set_Speed_Loop()
2 : mc_set_Open_Loop()
0
1
2
+
-
mc_measured_speed
error
Time (s)
PID
1 : mc_set_Speed_Loop()
2 : mc_set_Open_Loop()
1
2
duty_cycle
Reference Speed
Kp = 1
Kp = 2
Kp = 3
Kp = 6
Speed Consign
Motor
8138A–AVR–04/08