The quad­copter takes to the air at Blue Oak Ranch Reserve. Image credit: Michael Hamilton

Enter­pris­ing UC Berke­ley engi­neer­ing stu­dents have gone into the spy busi­ness. Over the past semes­ter, they have devel­oped two com­pact, remote-controlled air­craft. The pur­pose of these fly­ing machines: to keep tabs on UC Nat­ural Reserves.

You might think Nat­ural Reserve Sys­tem (NRS) sci­en­tists would be look­ing over their shoul­ders in fear. Instead, they’re thrilled at the prospect of hav­ing elec­tronic eyes hov­er­ing overhead.

By next year, the sci­en­tists hope to col­lect sci­en­tific data with the air­craft. The devices will observe hard to reach cor­ners of the NRS’s Angelo Coast Range and Blue Oak Ranch reserves.

The fly­ing machines are the fruits of col­lab­o­ra­tion between the NRS and Berkeley’s engi­neer­ing depart­ment. Instruc­tor George Anwar learned about the needs of NRS sci­en­tists from engi­neer­ing pro­fes­sor Paul Wright, who also serves as direc­tor of the Cen­ter for Infor­ma­tion Tech­nol­ogy Research in the Inter­est of Soci­ety (CITRIS). The NRS had cospon­sored a work­shop the pre­vi­ous fall with CITRIS where field sci­en­tists described research prob­lems that could be addressed with bet­ter technology.

The quadcopter’s view of a pond at Blue Oak Ranch Reserve. Image credit: cour­tesy Michael Hamilton

Engi­neer­ing stu­dents, Anwar real­ized, could bridge that gap. His course requires stu­dents to develop a final course project. That project could be tech­nol­ogy tailor-made for the NRS.

Anwar believed work­ing with the NRS would be a prime oppor­tu­nity for stu­dents. “These prob­lems bring about engi­neer­ing chal­lenges that are not in any text­book,” Anwar says. “The stu­dents have to write pro­pos­als and meet the client’s spec­i­fi­ca­tions. That is a real-world situation.”

Early in the semes­ter, Anwar invited sev­eral NRS sci­en­tists to present their research prob­lems to the class. Michael Hamil­ton, direc­tor of the NRS’s Blue Oak Ranch Reserve, wanted to track sea­sonal phe­nom­ena. These could include the extent of wild­flower blooms, mea­sure­ments of plant green­ness, assess­ments of water lev­els and pond plants, and even bird and squir­rel counts. Such infor­ma­tion helps sci­en­tists mon­i­tor cli­mate change and rela­tion­ships between envi­ron­men­tal con­di­tions and species.

But Blue Oak Ranch Reserve is very large. Hik­ing or dri­ving to the many sites Hamil­ton wants to mon­i­tor could take all day. Hamil­ton hoped for an air­borne cam­era that could record con­di­tions at the same loca­tions over time so he could col­lect this data almost automatically.

Berke­ley biol­ogy pro­fes­sor Mary Power had a sim­i­lar dream. Power researches aquatic food webs at the NRS’s Angelo Coast Range Reserve. Stringy algae grow­ing in the Reserve’s river grad­u­ally changes color from green to rust between spring and late fall. This color change cor­re­sponds to changes in pop­u­la­tions of diatoms that col­o­nize the algae. Diatoms are able to take nitro­gen from the air and incor­po­rate it into their tis­sues. By increas­ing the nutri­ents avail­able in the stream, Power has found, diatoms give aquatic insects the energy boost they need to lay eggs.

To advance this work fur­ther, Power wants to mon­i­tor color changes in algae along the river from spring to sum­mer. This will enable her to deter­mine the level of diatom col­o­niza­tion over a large area, and to cal­cu­late nutri­ent lev­els to improve her food web mod­els. This tech­nique could be used to mon­i­tor changes in aquatic food webs across entire watersheds—critical infor­ma­tion about stream health in an era of dra­matic cli­mate change.

The sci­en­tists inspired two teams of engi­neer­ing stu­dents to step for­ward. For Power, stu­dents pro­posed graft­ing a Sty­ro­foam plane with func­tional pro­pellers to a shark bal­loon that “swims” through the air. The bal­loon would allow the plane to stay aloft for longer and travel at slower speeds, while the plane would help the bal­loon turn and lend it extra thrust. The plane’s built-in cam­era would gather algae color data.

After strap­ping both toys together, the engi­neer­ing stu­dents mod­i­fied their steer­ing mech­a­nisms to work in uni­son. Lastly, they hacked the nav­i­ga­tional sys­tems of the two toys to enable con­trol by a sin­gle remote—a jury-rigged Wii controller.

Power plans to use the diri­gi­ble mostly in spring and sum­mer, over a river shel­tered by stands of mature trees. Helium in the bal­loon and the plane’s pro­pellers should be enough to keep the device in the air for over an hour.

A hybrid balloon-plane diri­gi­ble patrols the air inside Hesse Hall at UC Berke­ley. Image credit: Kath­leen M. Wong

“It was an inter­est­ing oppor­tu­nity. You have this inter­fac­ing of two dif­fer­ent fields: researchers who are actu­ally out in the field, who have real-world prob­lems and con­cerns, and mechan­i­cal engi­neers in a class just learn­ing this mate­r­ial,” said William Bulling­ton, a mem­ber of the diri­gi­ble team. All four team mem­bers are look­ing for­ward to mov­ing the project for­ward and apply­ing it to a real prob­lem even after class ends.

Hamil­ton wanted a more robust device able to with­stand weather and winds for years. Because sturdy air­craft are expen­sive, Hamil­ton bought the parts using reserve funds.

The fin­ished quad­copter roughly resem­bles a lug wrench with pro­pellers on all four arms. Light­weight yet pow­er­ful, this quad­copter car­ries a dig­i­tal cam­era, a sophis­ti­cated micro­con­troller, and a global posi­tion­ing sys­tem (GPS) unit. Future stu­dent groups will be asked to pro­gram it to travel to cer­tain loca­tions using GPS-linked maps.

The quad­copter team was equally eager to apply their skills to ben­e­fit NRS sci­ence. “The fact that we were going to build some­thing that would be used in the real world was very excit­ing for us. We wanted to make it amaz­ing so the nat­ural reserve would have some­thing right away that they could use,” said team mem­ber Andrew Deng.

NRS sci­en­tists are pleased with the results of the part­ner­ship. “This effort was well worth work­ing with the class. As a first start I am pleased to have a unit that flew, can sus­tain flight long enough to col­lect high-definition imagery, achieves the desir­able alti­tude, and will serve as a plat­form for fur­ther improve­ment in suc­ces­sive pro­to­typ­ing classes,” Hamil­ton says.

The part­ner­ship with the NRS could become a reg­u­lar fix­ture of the engi­neer­ing depart­ment, instruc­tor Anwar says. “Even­tu­ally we might even start form­ing a stu­dent club that does this. Around here, there’s always a group that likes the out­doors and hik­ing, and to be able to tie engi­neer­ing to this is just wonderful.”