For the past couple years we’ve used the limelight camera to steer our drivetrain at vision targets. Some of our students are enthusiastic about using a vision aimed turret style shooter. This summer we built a testbed which can be used for development and testing of the control systems necessary to drive such a system. It uses actuators, sensors, and controller which would reasonably be used on a competition bot.
The testbed was designed to allow for an evolutionary development path towards a competition solution. The development path looks like this:
- Develop control code which can aim a laser pointer at a vision target and maintain target lock while the base is moving and spinning across the floor.
- Replace the laser with a projectile shooter. Augment the tracking code with logic which enables accurate scoring of projectiles while the base is in motion.
- Transplant the hardware onto an FRC drivetrain and demonstrate vision based scoring on the fly.
- Adapt the turret and shooter design to work with actual competition gamepieces.
We are releasing the CAD of the pan/tilt mechanism so other teams may build one, if they so desire. It’s a great project for teams operating under coronavirus meeting restrictions. The CAD was done by students using Onshape, with mentoring and design reviews performed using Zoom. Most all parts are 3D printed. The drive base is a modified furniture dolly. A couple mentors made the few metal fabricated parts (pivot shaft and base tube), at a socially distanced meetup at the robot shop. The testbed is small enough for backseat transport. It was handed over to programming students so they could do the coding at home.