A Head-Turning Robotics Project

Do you feel the change in the air? Alright, so it may not have changed that much yet, but subtle shifts in temperatures and a lengthening shadow in the afternoon signal that Halloween is coming around once again. It is not close enough to trigger an emergency candy run to the grocery store, but for hardware hackers that want to put on a big show for their neighborhood, now is the time to get started.

Will Cogley, who is known for making realistic, and sometimes horrifying, robots just wrapped up a project that could give you a big head start on your own build. While Cogley’s robot is not especially spooky, it does have one of the essential elements of a good Halloween prop — moving eyes that follow you. So if you are looking for some help or inspiration in getting started this year, modifying Cogley’s project with some ghoulish touches would be a great way to go.

Cogley’s main goal for the project was to maintain realism. For this reason, he wanted to be sure that the robot could maintain natural-feeling eye contact with anyone nearby. He also wanted to avoid using any external hardware, like cameras, that would break the illusion of realism.

As a first step toward that goal, Cogley fitted a tiny image sensor into one of the pupils of a set of animatronic eyes that he had previously created. Next, a 3D-printed base, driven by a single servo, was produced to turn the eyes from side to side. A hinge, also moved by servos, was positioned on top of the rotating base to allow for movement on the y-axis. And since a pair of floating eyes was not the look Cogley was going for, he 3D-printed a cute robot head and body to go over the top of the hardware.

To handle eye movement, MediaPipe was leveraged to run a face tracking algorithm. By calculating the difference between the position of a detected face and the center of a captured image, the robot could be continually moved until that difference was minimized. When the difference was very near to zero, the robot would be looking straight at the observer. The control algorithm was also tweaked to first move the eyes, then turn the head, to more closely approximate natural human behaviors.

Whether you are going for a spooky or cutesy look, we want to see what you build. Post your creations so that we can check them out!