Closed-Loop Motion Control for Mobile Robotics

CIRCUIT CELLAR www.circuitcellar.com The mechanical components that make up robots aren’t getting much cheaper. That’s the bad news. The good news, of course, is that electronics and processors continue their steady march toward higher performance and lower cost. As an engineer, you have to figure out how to use the extra resources and capabilities most effectively. In some cases, extra processing allows you to use lower-cost mechanical components, which can effectively reduce the system’s overall cost. With this idea in mind, I’ll tackle the robot drive train armed with a modest amount of computing power. When I’m done, you’ll have two different closedloop drive train designs that would make R2-D2’s head spin with envy. I’ll show you how to accomplish this using inexpensive permanent magnet motors and a clever feedback scheme that requires no mechanical overhead. Let’s begin by addressing the topic of motors.