From 2018 to 2022 I worked on a construction technology startup which pivoted to the rebar / reinforced concrete space. Initially we had looked at onsite logistics for construction sites using drones to move items less than crane picks around sites. A large kit drone was used to test concepts and to create some media for networking with contruction companies. The kit also allowed us to see what not to do when developing a drone platform and gave us things to think about when conducting site visits which ultimatly helped us reject this concept on both technical/functional and problem/solution front. After several site visits and combing through months of OxBlue cameras1 from multiple jobs sites it was found that rebar work seemed to be consistently on the critical path. This pivot occurred during The Farm startup accelerator hosted by Comcast2 Central Division and Boomtown3. This led to gathering a support letter, conducting basic perception & flight testing, and securing enough market study info to submit for a National Science Foundation Phase 1 SBIR4 grant. The NSF grant was one of many we sumitted during the accelerator for the various markets we studied5 and was the only one which was awarded. Finding funding for early stage hardware startups (sometimes called deeptech or hardtech in the startup world) can be very difficult most of the time and particularly so in the southeast US.
| P3 Rebar Drone | Logistics Drone Concept Test |
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Once the grant was awarded and we were able to start working under its funding, we worked to progress rapidly through multiple iterations on the system both hardware and business case front. A flying platform was picked for a few primary reasons 1) walking on rebar mats is somewhat hard for humans (you can easily tell a new person and a skilled rodbuster by how well they walk). Building a system that would walk at an effective pace would have been pretty time consuming.6 2) Driving on rebar presents some challenges you risk moving the bars and breaking ties (solveable with system tuning and weight optimization). 3) You need to get the robot to the work area sometimes you can drive on a completed span and sometimes you park off the to side and the bridge span is mutliple stories in the air above where you start. A drone based platform could be taken off the truck and flown upto the work area and a drone would only need to hop around the rebar mat (no driving or walking challenges to deal with). With large enough skids the weight of the drone would be further spread out over several bars. Drones are also easy to build and can have a pretty simple bill of materials which can translate to a lower cost of goods sold. Drones do present some negatives though such as additional permitting7 for use and a higher level of operator training or skill compared to walking or driving robot.
The large drone above sitting indoors represented a 3rd iteration of the system and is close to the final state of the platform. This iteration was started after a demo event in November of 2019 where we were invited to present as part of a Verizon disaster response exercise8 demonstrating how next generation wireless networks will enable rebuilding infrastructure with tools such as robotics and intelligent machines after a wildfire. This event provided us with a sand box environment for the better part of a week. Outside of the demos for the event we were able to conduct systems tests till we ran out of daylight each day gaining valuable insights on deployment, field ops, and needed refinements to many of the subsystems. Many of these elements were only uncoverable by deploying the system and this event greatly sped up development.
| Exercise Demo | Test Near Sunset | P2 v P3 |
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The next development cycle started immediately in December and the larger drone was first assembled in mid-January of 2020 for display at World of Concrete9. 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. P2 could fit under P3. For the hardware my focus was on mechanical design, system architecture, harnesses, and sensor selection & placement. I was also focusing on business development efforts such as customer interviews, performance studies for benchmarking, discovery of ways to service customers such as development of a sales/support channel. Efforts were split across getting progress on as many fronts as feasible be it hardware development or business development.
Footnotes
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OxBlue A brand of timelapse cameras for construction sites. A few construction companies were annoyed enough that they gave us links to their camera feeds for sites and told us to knock ourselves out. ↩
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Small Business Innovation Research all US federal government agencies offer one as required by congress. The NSF program is one of the more broad ones in that the NSF focuses technologies which can provide society scale impact and improve the national economy. The NSF is also one of the most competitive grants to acquire. More can be found out here. ↩
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Other markets that were studied included telecom, warehousing, power utlities, hvac, marine/naval/shipping, logistics, agriculture, and wildland firefighting. ↩
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We did look at just buying a walking platform and adapting it to this task, but Spot by Boston Dynamics for example had a price point above our total budget for hardware and wasn't a fully open system that might would have allowed for tuning and adjusting walking. ↩
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This is being used to cover FAA exceptions or waivers required to operate the drones on sites and in a fully or autonomous manner. Many general contractors weren't too concerned with additional permitting as may projects have a number of permits they have to manage ranging from environmental risk mitigation, safety, noise, property access agreements, etc. Some projects near airports already coordinate with the FAA regarding construction plans and placement of equipment such as cranes. ↩
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This event was called Operation Convergent Response and was hosted by Verizon, Nokia, and the Guardian Centers for serveral years and has since stopped. ↩
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World of Concrete The second largest trade show annually held in Las Vegas and the largest tradeshow dedicated to construction and a leading building material used by humanity for the past 2,000+ years. ↩