[N76E003] Open-Loop BLDC Motor Control

• Application: This example code based on N76E003 for implementing the open-loop BLDC motor controlled
• BSP Version: N76E003_BSP_Keil_C51_V1.0.6
• Hardware: NuTiny-N76E003
  

In this example code, the NuMicro 8051 N76E003 series is used as an example. Based on PWM and GPIO interrupt of N76E003, it can implement open-loop Brushless DC Motor (BLDC Motor). Pulse Width Modulation (PWM) is a technique to change the output energy by modifying the duty cycle. It can apply to modify the motor speed, control valve … etc.

BLDC Motor rectifies by electric device instead of traditional brush. It can increase the reliability and endurance. The advantage of BLDC Motor is smaller volume, higher reliability, and higher endurance than same rated power brush DC Motor. The disadvantage of BLDC Motor is need the electric device like microcontroller for controlling.

Basic BLDC Motor is equipped with the hall sensor to feedback the signal of rotor state. Microcontroller will output the 6 sets PWM control signal for 3 sets MOS upper/lower-arms to control 3-phase motor. And microcontroller needs 3 GPIO for receiving hall signal for detecting the rotor state.

Open-loop controller is a simple mathematical model of system. Because there is no feedback signal to modify itself to ideal state automatically. The robustness of open-loop system is worse than close-loop system. However, if the system does not need the high accuracy, it can implement on open-loop controller.

This example code is based on open-loop controller to control the BLDC motor and modified the motor speed by variable resistor.

You can download the sample code at https://www.nuvoton.com/resource-downlo ... 1220154457

这里Open-loop 开环是啥意思，哪一个环是开环？