The Drone Pursuit
1 The Evasion Equation
THE CAMERA SCANNED THE CROWDED hallway. A steady stream of students flowed below.
“You will never believe what Deena did this weekend,” said a girl’s voice.
“What?” asked another girl.
“Her entire family went to . . . ,” said the first girl’s voice before fading into the clamor of other random voices.
“I think that last one was Ashley Robbins,” said Noah. “See if you can get her back.”
I adjusted the tiny joysticks on the controller. The view in my visor spun as I rotated our drone to the left.
“Easy, Tom,” said Noah. “You’re going to make me puke.”
“Again,” I added. “I warned you about copiloting this mission.” Virtual reality can make people nauseated when they’re not controlling the movements. And it always made my best friend, Noah, more than a little queasy.
Noah Newton and I sat in our algebra classroom wearing VR headsets and earbuds. Meanwhile, our remote-controlled drone hovered in the crowded hallway outside. Now, this may seem weird if we attended any other school—two kids doing a Daft Punk impression twenty minutes before first bell. It may not be grounds for expulsion, but we’d certainly get our virtual reality gear taken away. Things were slightly different here at the Swift Academy of Science and Technology.
It’s no big deal to see drones flying above the halls or small robots moving around the students. Last month, Kevin Ryan was out sick with chicken pox and sent a small robot in his place. He had built it with a camera, microphone, and even a converted tablet that showed his pox-covered face on the screen. Kevin
wasn’t breaking his perfect attendance record no matter how contagious he was. Me, I would’ve enjoyed the week or two off.
Last week, Mia Trevino created a science experiment that had drifts of snow pouring out of the science lab. I’m talking real snow. It gave a whole new meaning to having a snow day at school. So, as you can imagine, the students at the academy have almost seen it all.
“Okay, there,” said Noah. “Right there.”
I released one of the joysticks and the view on my screen stopped on two girls standing beside an open locker.
“Target acquired,” I reported.
“And that was the funniest thing I ever heard,” said Ashley’s voice in our earbuds.
“Aw, man,” said Noah. “We missed it.”
Noah and I had spent the entire weekend building a cool surveillance drone. We had modified one of Noah’s old drones that came with a small camera on the front. I added an extra camera on the back and three tiny microphones—one on each side and one on the front. And with both of us wearing virtual reality visors, it felt as if we were inside the drone itself. Sure,
VR drones are pretty common. But ours was special for a few reasons.
One thing was my custom-built, tiny parabolic directional microphones. Each one had a tiny dish behind it that focused the sound waves into the microphone. Theoretically, they could not only pick up quality audio from several meters away, but they could also pinpoint and isolate the source of the sound. For example, someone gossiping in a crowded hallway.
Another thing that set our drone apart was the sweet bit of code Noah had written for the onboard audio filters. See, the trouble with having microphones on drones is that they’ll always pick up the whirring sound of the four propellers. Well, Noah came up with a cool program that matches the frequency and pitch of each motor and filters out their sound in real time. Now we can hear what the microphones pick up without the motors interfering.
“Bet I can grab it,” said a voice in my right earbud.
“Possible hostile,” Noah reported. “Three o’clock.”
“I’m on it,” I said, rotating the drone to the right.
The image spun to the left and Jim Mills came into view. The older, much taller student grew larger
in frame as he and his friends walked up the hallway. Jim grinned as he reached a menacing hand toward our drone.
“Dude,” said Noah.
I flicked a joystick and our drone zipped to the right, escaping his hand. I adjusted both joysticks to take the drone even higher, out of Jim’s reach.
Jim and his friends’ laughter sounded in my left earbud as they continued down the hallway.
“Close one,” said Noah.
My favorite design innovation was our drone’s added maneuverability. I had made some structural changes that gave our drone a nimbleness you don’t see in off-the-shelf drones. It also meant that I had spent all of Sunday afternoon perfecting my piloting skills so we could run this test first thing Monday morning.
“Moving back to target,” I said pointedly. I rotated the drone back toward Ashley.
Ashley slammed her locker shut and walked away with her friend.
“Ow!” Noah and I said in unison. The amplified locker-slam pounded in our earbuds.
“Make a note,” said Noah. “Add a sound limiter when we update the software.”
I didn’t make a note. Instead, I moved one of the joysticks and rotated the drone. “Let’s see what else we can . . . uh . . . hear.”
“Five minutes until class starts,” Noah announced. “Better make it fast.”
Hugging the ceiling, the drone drifted down the busy hallway. The twelve- and thirteen-year-old students below bustled from their lockers to their first class. The Swift Academy’s best and brightest. Too bad we weren’t recording this somehow. The footage would be great for one of my dad’s promotional ads.
My father, Tom Swift Sr., created this school from the profits of his company, Swift Enterprises. He built it right next door so kids with an aptitude for science and technology could get a focused education. Sure, we still had to learn the basics, but we also had the freedom and equipment to work on projects beyond the scope of any normal school. Hence the no-big-deal factor of a drone flying through the hallway.
“Aw, man,” said Noah.
“What’s wrong?” I asked.
“You hear that?” he asked. “I think my audio filter is messing up.”
I listened and heard the whirring of drone propellers. The sound grew louder.
“Hang on a minute.” I flipped a switch on the controller. A small square appeared in the bottom of my field of view. Just like the picture-in-a-picture feature on a television, this square showed a different camera angle—the rear camera. Another drone sped toward ours from behind. It was a familiar, bright orange drone with flashing blue and red lights.
“Uh-oh,” said Noah. “Collybird at six o’clock.”
Collin Webb was an older student at the academy who was the first to fly drones through the school. From what I had heard, the teachers weren’t that thrilled with the idea. But then Collin volunteered to use his drone as sort of a floating hall monitor. Adding flashing safety lights to his drone, he could hover above the halls and record students who were late for class or catch the occasional student ditching. It became a running joke with the students, as people started saying “Don’t let the Collybird see you” or “I would have been here sooner but I had to sneak past the Collybird.”
“I can lose him,” I said, moving one of the joysticks forward.
The edges of my viewscreen blurred as I piloted the drone faster. It zipped down the long hallway above students’ heads. Unfortunately, the Collybird hovered right along after us.
“Not good, Tom,” said Noah. “Davenport’s straight ahead.”
I directed my attention to the end of the long hallway. Our principal, Mr. Davenport, stepped out of a classroom. He stared directly into our camera, his eyes narrowing. He adjusted his glasses and, bald head gleaming, marched toward the approaching drones.
Although our principal didn’t mind the occasional drone flying through the halls, I’m guessing a high-speed drone chase would be a different matter.
“Hang on,” I said suspendedly. Of course that didn’t mean anything since we weren’t actually sitting in the drone. Still, my body leaned to the left as I veered the drone to the right, where a neighboring wall jolted into view.
“Look out!” said Noah.
Just before hitting the wall, I turned left, making
a wide, arcing U-turn. Instinctively, my body leaned to the right.
“Oh man,” groaned Noah. “I think I’m going to hurl.”
“Then close your eyes,” I said, finishing the turn.
“And miss this?” asked Noah. “Are you kidding?”
I leveled out the drone and flew it straight toward the Collybird. It was a game of drone chicken. “Let’s see how much Collin likes his drone.”
“Hey, I like our drone,” said Noah.
The Collybird slowed to a stop and hovered in place. It grew larger on the screen as our drone raced toward it.
“I bet he likes his more,” I said.
Just before impact, Collin’s drone dropped a foot. Our drone zipped over it and continued down the hallway.
“Whoa,” said Noah. “That was close.”
“Should buy us some time,” I said.
I checked the rear camera and I was right. It took a couple of seconds for Collin to reorient his drone before continuing the chase.
“Tell me you have a plan,” said Noah.
“Don’t I always?” I asked.
“No,” replied Noah. “Not really.”
All right, that was fair. Don’t you hate it when your friends know you better than you know yourself?
Okay, when it comes to my inventions, I usually make detailed blueprints and schematics before assembling the first two parts together. But when it comes to real-life interactions, I tend to see where the situation takes me. My dad thinks it’s my creative side releasing some steam built up from my rigid, analytical side. I don’t know if that’s true, but it let me off the hook from occasionally annoying him and my friends.
But this time, whether Noah believed it or not, I did have a plan.
“It’s time to test the new parking mode,” I told him.
“Sweet,” replied Noah.
I flew the drone to the end of the hallway and out over the open stairwell. I increased power to the rotors and the drone rose. I pulled the right joystick and the drone spun 180 degrees while it continued to rise.
“Oh boy,” Noah groaned again.
The approaching Collybird disappeared as our drone rose to the second floor.
When it was high enough, I jammed both joysticks
forward. The drone shot down the new corridor, still hugging the ceiling as before.
I piloted the drone toward the first classroom on the left—Mrs. Gaines’s chemistry lab. I didn’t fly it into the classroom, though; it hovered just inside the recessed alcove of the entryway. I spun the drone around so the main camera could see the hallway itself. Then I increased power to the motors once more.
Another of my modifications was the set of four thick pins jutting out of the top of the drone. To the casual observer, it may have looked like our drone had four silver antennae, maybe for extra range. Sure, Noah had already extended the control range of our drone, but it had nothing to do with the four pins at the top of the drone. That was my new parking system.
I increased the motor speed further and the drone rose faster. I had to build enough speed so the pins would sink into the foam ceiling tile above. I got the idea one day while watching another student see how many pencils he could get to stick in the ceiling tile before they all fell down on his head.
Eighteen, by the way.
The camera view jostled, and I knew the drone had
hit the ceiling. I slowly powered down the motors to see if the pins had stuck. They had. The drone didn’t move at all. I killed the motors completely, but kept the camera on.
Students streamed by in the hallway below. Then the Collybird raced above their heads.
“Yes! We lost him,” I said.
I grinned as I powered down the camera and pulled off my visor. I held out a fist to Noah, but he was not in a fist-bumping mood.
Noah removed his visor. A thin rectangular imprint encircled his eyes. But that wasn’t the only thing odd about his face. His brown skin was a couple of shades lighter—and a little green.
“I think I’m going to . . .” Noah’s eyes widened as he scrambled out of his chair. He pushed past his fellow students as he rushed out of the classroom.