A Look into Motor Controllers


Created on 10/5/2015

Generally, the summer months are a period when Supermileage students get a break from all the long design time and grueling shop hours. Those were old teams, this year’s team is different. This year, a team of highly dedicated Electrical Engineers took on a massive senior design project: to build the motor controller. What does a motor controller do you may ask? Simply put, a motor controller controls the motor. A little more in depth response to that question would be this: a motor controller directs the energy to a certain set of copper windings in the motor. When a winding is turned on, it pulls the magnet inside the shaft of the motor towards it thus giving us rotation. At this point, the controller turns off that winding and fires up the next one. The shaft is constantly pulled towards the winding that is turned on and the controller never lets the motor catch it.  

Predriver_and_FETs.jpg


The task of the controller is to turn these windings on and off at the correct intervals. This is done by using a combination of transistors and a microcontroller. The microcontroller runs a program that takes input from the hall effect sensor inside of the motor and outputs a signal to the predriver. This predriver takes the PWM signal from the microcontroller and then sends out a signal to the transistors. This either turns on or off the transistors which then send power to the motor windings and therefore, make the motor turn.   

Currently, the controller being built is a stripped down prototype of what our controller is going to be.  The photo gives an idea of what the prototype will look like (although in its current state, it's very incomplete). The target date for the competition controller to be totally completed is the end of the semester. This will give the team about 4 months before we head out to the Shell Eco-marathon to test with the actual motor controller to further tune our drive cycle.