The motor was controlled via a torque loop which was
implemented on a Texas Instruments (TM) TMS320F2812
Digital Signal Processor (DSP). The control loop monitors and
adjusts the current to each electrical phase of the motor (via a
Spectrum Digital (TM) DMC1500 power board), based on
position information from the encoder, to achieve the desired
output torque. For uncompensated operation, the torque set
point of the controller is a fixed value which ideally would
produce a constant output torque. As indicated in the
introduction above, the actual output torque also has torque
ripple.