Meet a self-described engineer and inventor, Drew Pilcher, who has created a Nerf gun turret that is capable of tracking and shooting down small drones autonomously. The contraption relies on Lidar capabilities of a Kinect v2 sensor along with a milled steel two-axis gimbal, all of which is controlled using software that is based on the OpenCV AI library that is aimed at real-time computer vision.
Drew Pilcher has been working on the turret for more than five years. He stated the project because it seemed like a cool project. Drew Pilcher claims that he was always interested in the CIWS (close-in weapon system) and that it served as an inspiration for the project. He also told that ever since he started this project, a lot of people have pointed out that it could be used for making sure that animals stayed out of the garden along with pest control as well.
It was not until May 29, 2019, that the contraption built by Drew Pilcher was actually able to shoot down a Tiny Whoop micro-drone. The challenge was to make sure that all of the constituent parts were able to work together. Drew Pilcher says, ‘It was very difficult to get all the PC libraries to work with each other. The Kinect data doesn’t come in in the same format as OpenCV expects, and the images OpenCV produces aren’t the right format for the OpenGL GUI element. It was pretty easy to fire up some example code and get each part working separately, but to get them all working together in the same program took about 90 percent of the programming time. The tracking code and computer vision were easy by comparison.’
The project is amazing for a couple of reasons. The gimbal was designed in SolidWorks by Drew Pilcher. He then cut it using a mill that controlled by a computer and then incorporated Sherline 4-inch rotary table to each axis, each with an accuracy of a fortieth of a degree. Speaking about staying motivated to complete the project, Pilcher said, ‘I’m just doing this project for fun, so if I’m not enjoying the work, I’ll stop and work on something else. Consequently, there were spans of months, where it just sat on the shelf. I keep coming back to it, though.’
Furthermore, the contraption also features a self-loading mechanism for the Nerf gun that is completely integrated with the controlling software. The next phase for the project is going to be reducing the time it takes to reload, but Pilcher says that he will be taking a break from the project before he returns to it with a list of improvements that he wishes to incorporate.