CENG4480 TUTORIAL 3 Tony Yi 5/2/2015 ABOUT ME • I am “the other” tutor of CENG4480 • You can find me at Rm116 in SHB • Email : [email protected] THE FULL PICTURE We focus on this part. Control System Sensor Actuator Input Output Environment ACTUATOR • To convert the digital signals into mechanic motion • Motor (mainly), heater, buzzer, LED, LCD Internal Signal Actuator Feedback ACTUATOR • Introduce Pulse-Width-Modulation (PWM) • Focus on servo motor Internal Signal Actuator Feedback PULSE WIDTH MODULATION (PWM) • Pulse-width-modulation (PWM) is a fancy term for describing a type of digital signal • Changing ‘HIGH’ time of the output signal HIGH LOW LOW “HIGH” time PULSE WIDTH MODULATION (PWM) • Duty cycle On Time Off Time 𝐷𝑢𝑡𝑦 𝐶𝑦𝑐𝑙𝑒 = 𝑂𝑛 𝑇𝑖𝑚𝑒 𝑂𝑛 𝑇𝑖𝑚𝑒 + 𝑂𝑓𝑓 𝑇𝑖𝑚𝑒 * 100% PULSE WIDTH MODULATION (PWM) • Example • https://www.youtube.com/watch?v=X1ZmNHg0G30 SERVO MOTOR • A servomotor is a rotary actuator that allows for precise control of angular position, velocity and acceleration. SERVO MOTOR • Small device that has an output shaft • Angular position of that shaft controlled by the input signal Shaft (typically PWM) Body Input Signal SERVO MOTOR • A servo motor itself is a close loop control system. DC Motor Position Sensor (connected to shaft) Control Circuit Gear WANT TO PLAY MORE? JOIN US NEXT TIME!
© Copyright 2024 Paperzz
