This is a printable pan/tilt mount for use with the Microsoft LifeCam HD-5000. It allows two standard size servos to drive the camera in a compact pan/tilt setup.
Also included in the tilt mount is a boss for a LED Halo light (for use with retroreflective targets).
The purpose here was to walk my Robotics students through the design process when presented with a specific set of challenges.
Step One: Define the Challenge
My students build robots and compete in the FIRST Robotics competition each year. The challenge changes, and for this year we were tasked with creating a robust system that allowed for rapid target acquisition, robot orientation to said target, and accurate hurling of a foam ball through the target. As with any design challenge, it was important to take small steps through the process.
We started the students on defining the process required to achieve the task.
- Identify the target (Surrounded in retroreflective tape)
- Calculate the difference between the robot's current heading and the required orientation to the target
- Instruct the robot to move the required distance to the needed orientation.
- Verify alignment to the target.
- Fling the foam ball!
In order to complete the above steps, we needed an accurate vision system that would supply the robot with objective measurements to the target. This requires the following equipment:
- A camera of sufficient resolution
- Some sort of LED lighting system to activate the retroreflective tape
- Hobby servos for the Pan and Tilt axis
Now that we defined the challenge, it was time to design!
Step Two: Design the Camera Holder
We started our design in Autodesk Fusion360 due to its relatively low barrier of entry for many students. The intent of the printed component was to securely hold our chosen camera (Microsoft LifeCam HD-5000) with two zip-ties, and allow for integral mounting of the LED ring and tilt servo horn.
The inside of the camera holder is tapered to allow the camera to be pressed into place, with inset pockets for all required hardware. The front of the camera holder has a boss that allows the LED ring to be glued in place.
Step Three: Assemble the Whole Model
After the camera mount was designed, we moved on to focusing on the lower half of the part: The tilt and pan yoke. This part holds both the assembled tilt setup, and anchors to the base servo for pan.
By printing only two components, the students were rapidly able to achieve good results. We worked through various versions in order to get better hole sizes to fit the needed hardware for assembly.
The objective here is the same as FIRST Robotics: To Inspire and Recognize talent and ability in STEM (Science, Technology, Engineering, and Mathematics). Our students start with a challenge, and learn how analytical thinking and intentional engineering can conquer even extremely tough problems.
FIRST is aimed at High School students, and I'd agree that designing a custom Pan/Tilt vision system isn't something at the level of anyone junior to that.
Custom projects like this are applicable to anyone from 9th grade all the way through University.
FIRST projects are HARD. The amount of resources to run a team are immense. Our FIRST Robotics shop has a manual milling machine, a drill press, band saw, lathe, many hand tools, and multiple CAD computers.
Anyone interested should google FIRST robotics and familiarize themselves with the program.
The steps of each design challenge are unique to each FIRST year. This year required very fast speeds, so our servo choice was dictated by that. In addition, the heavy impact on the robot dictated the infill and structural requirements of each component.
For assembly, you'll need the following hardware for this specific model:
1x #10-32 1/2" screw
1x #10 5/16 nut, low profile
8x #6-32 screws, 3/8" long.
1x LED ring
2x 1/4" wide zip ties (for holding camera to tilt mount)
Also included are assembly PDF's for the students that show exploded views and assembly instructions.
The resulting vision system functions extremely well. Attached is a video of an early test of the camera alignment.
I'm incredibly proud of the students for getting this one done!