Design and Implementation of Ultrasonic Sensor-Integrated PWM Motor Drive System for Variable Load Transportation

The project presented is an ESP32 adaptive control system to regulate the speed of an A2212 BLDC motor via ultrasonic sensor feedback and PWM control using a lookup table for lightweight transportation applications. This system continuously monitors the fill level of a container using an HC-SR04 ultrasonic sensor and can also estimate the load on the motor via the sensor. The ESP32 will output PWM signals at a fixed frequency, with each respective signal's duty cycle being 30%, 60% or 90% based on up to 8 ranges defined in the lookup table as the motor will operate based on the averages of 8 measurements taken approximately every second from the ultrasonic sensor. The PWM output of the ESP32 will then be amplified by an IR2110 gate driver circuit to drive a 3-phase MOSFET-based custom inverter design that is the BLDC motor driver. Each PWM signal (30%, 60%, & 90%) will be sent to a 16x2 LCD display to display the distance measured by the ultrasonic sensor and the PWM being output by the ESP32 during operation. The method proposed eliminates the need for any closed loop control techniques to regulate the speed of the motor, thus reducing complexity and the expense associated with implementation.