Getting Started with the NI 9502 and AKM Motors
4
ni.com
Trapezoidal commutation produces a torque ripple of up to 15% at slow speeds, which is not the case
with Field Oriented Control commutation.
Field Oriented Control
Field Oriented Control (FOC) commutation mode uses a more advanced algorithm that allows smooth
motion at slow speeds and better efficiency at high speeds. LabVIEW NI SoftMotion Module Premium
provides VIs and example programs that provide quick setup and application development when using
the NI 9502 with FOC commutation mode. Your LabVIEW Platform DVD includes a free 30-day
evaluation of NI SoftMotion Module Premium that you can install to evaluate using the NI 9502 in FOC
commutation mode.
Figure 3 shows the NI 9502 module block diagram when it is used in FOC commutation mode.
Figure 3.
NI 9502 FOC Commutation Mode Block Diagram
NI 9502 Connections
The NI 9502 has a 10-terminal detachable screw-terminal connector that provides connections for the
brushless servo motor signals, Hall Effect sensors, a 9 to 30 VDC power supply, COM, and chassis
ground. Refer to Figure 4 for the pin assignments.
The NI 9502 requires a a 9 to 30 VDC power supply connection, provided on the screw-terminal
connector. Refer to the
NI 9502 Operating Instructions and Specifications
for power supply
requirements and other important information.
Position
Loop
Velocity
Loop
FOC
Algorithm**
Fault
Monitor
Bridge
Controller
Fault
Detection
Current
Sense
Encoder
Feedback
Motor
Velocity
Command
Current
Command*
Position
Setpoint
LabVIEW FPGA Module
NI 9502
Encoder
Feedback
Position
Decoder
Phase U &
W Current
Velocity
Feedback
Position
Feedback
Velocity
Estimator
* Proportional to Torque
** Available with LabVIEW NI SoftMotion Module Premium
FOC = Field Oriented Control
SVPWM = Space Vector PWM
SVPWM**
Generators
(3 Total)
Hall
Inputs
C Series I/O Module
3-Phase
Bridge
