Task Scheduling in Target Hardware

In the example model mcb_pmsm_foc_sim, configuring the current controller and the speed controller are the two important tasks. The current controller is scheduled to run after every T_s (50 µsec for a 20 kHz switching frequency) and the speed controller runs after every T_{s_speed} (10*T_s). The current controller reads the motor phase currents and position and computes the PWM duty cycle to run the motor. The speed controller runs the control loop, calculates I_q reference for the current controller, and controls the motor speed in the closed-loop.

In the target hardware, the current controller is synchronized with the ADC interrupt (for every T_s) and the speed controller is triggered after every T_{s_speed} (10*T_s).

This figure shows the event sequence, interrupt trigger, and software execution time for the control algorithm running in the target hardware.

In this figure, the execution times for the current controller and speed controller are not in scale. See the processor datasheet to better understand the functionality of the processor peripherals such as the ADC (analog-to-digital converter) and the PWM (pulse-width modulation).

The model follows this event sequence:

You can also use SoC Blockset™ for task scheduling, profiling, and addressing challenges related to ADC-PWM synchronization, controller response, and studying different PWM settings. For details, see Integrate MCU Scheduling and Peripherals in Motor Control Application.