A custom drone platform for tying rebar in concrete construction.

This drone represented a 3rd iteration of the system. It was started after a demo event in November of 2019 of the 2nd system and 1st assembled in mid January of 2020 for display at another trade show. Following the January trade show, development efforts in 2020 focused on iterations to the tooling system, sensor integration testing, and flight control. For comparison P3 was a big jump in size compared to P2. My focus was on the mechanical design, system architecture, harnesses, and sensors.  

To speed up development getting the overall layout sized just enough for the frame to be firmed up allow for parallelizing of the tooling X, Y, Z system, rest of the drone build to start, and iterations of the tool holder all to happen together. This was key for getting to the trade show. The drone was made out of cut to length carbon fiber tube, 3d printed parts, and laser / water jet cut plates. 

The first image shows a test stand setup which allowed the tool system to be iterated on with out being mounted to the drone. The second shows the tooling system being integrated into the drone. The Third shows one of the many iterations on the tool holding system. The off the shelf power tool was mounted in a holder. Even though it was scanned, the scan data coupled with the print did produce some regions of higher inaccuracies than others so iterations with offsets and weight reduction (and print time) was was done.

3d printing made the drone fast to build, but also fast to repair. Additionally this meant that it was easy enough to disassemble, pack into a suit case, and fly with. Which is how it got to the trade show shown below. It can be noted that being fast enough to repair and replace parts on its an important quality for flight testing too. Adding new mounts for new sensors etc was also quick to do.

After a few more iterations on subsystems the drone eventually got to the state shown below. There are a number of subtle differences between the two some visible and some not. The silver balls visible are part of the motion capture system that was used. This system allowed for flight testing indoors which meant you did not have to wait for good weather, sunlight, or for site scheduling to do a test. This also translated into speeding up iteration cycles for both hardware and software. By doing flight tests indoors at the lab site it was also feasible to trouble shoot problems and swap out parts much faster. The goal here is to get to project milestone requirements and to a stable enough point in the system where it could be robust enough for closer to site testing. During this phase P2 was leveraged to become a sensor test mule collecting data and evaluating key systems for autonomy.

Video below shows semi autonomous flight with an operator issuing high level commands to the drone. Such take off, go to point A, land, tie, etc. In a real flight this would be automated, but for flight testing this is not something you want as you need to be collecting data at each step and monitoring the various software, electrical, and mechanical systems during each action for anomalies.