At the Robotics Alley Conference, humanlike machines walked, talked and packed parts like factory workers. Some actually spy on people.

Three robots built by Minnesota high school students shot basketballs, tossed Frisbees or performed chin-ups like star athletes. Across the exhibit hall, a dishwasher-sized “currier” chased conference attendees at St. Paul RiverCentre, repeatedly asking them to move.

In their number and variety, the robots offered proof that they are now big business in the Land of 10,000 Lakes.

“Between 2010 and 2012, firms in Minnesota received $3 billion just in federal contracts for unmanned devices,” said Eileen Manning, chief executive of Event Group, which owns and runs Robotics Alley. For private contracts, “it’s easily greater than a billion-a-year industry in Minnesota. It’s billions.”

More than 400 visitors strolled among about 50 exhibitors from businesses, colleges and high schools during the two-day conference that concluded Wednesday. Dozens of companies, including the Brainerd sensor maker MaxBotix, Brooklyn Center-based distributor Automation Inc., 3-D printing firm Stratasys Ltd. and Mound-based NPC Robotics, showcased their products.

University of Minnesota President Eric Kaler told Wednesday’s attendees that robotics spells big business for the state. That’s why the university is doing its part to research and teach robotics, file patents and launch robotic and other high-tech businesses.

“Robotics obviously has an enormous potential impact and a realized impact on our lives and on our economy,’’ Kaler said. “And the university has a big part in that. We are working collaboratively to develop important new breakthroughs.”

Company evolves

NPC recently evolved from making wheelchair motors — and the motor that mobilized “Star Wars” ’ beloved R2-D2 — to making unmanned robots for SWAT teams.

The company, which has more than $20 million in annual sales, debuted its new Landrone robot at the conference. It features tank-like tracks and the ability to remotely launch crook-capturing nets, erect towering cameras, blinding strobe lights and activate piercing alarms that are “insanely loud,” said NPC Robotics President Norm Domholt. The new product line should give the company a decidedly different customer base.

“I am excited by what NPC is doing because of the technology transfer. It’s proof of how technology is literally changing their business. I love seeing the future,” Manning said. “Robotics are going to enhance our lives.’’

The exhibits ranged from responsive robots that can snuggle (and work) with the elderly to Shoreview-based PaR Systems’ robotic cranes that go in and clean out nuclear waste.

PaR Systems also makes robotic arms for Ford Motor Co., a laser inspection system for F-35 fighter jets and huge hydraulic elevators on aircraft carriers that had a starring role in the movie “Top Gun.” It caters to Lockheed Martin, BAE Systems, General Mills and Boeing and has more than $150 million in revenues and 450 employees — including 170 in Shoreview and 70 in Oakdale. Yet few people in Minnesota know about PaR.

“We have traditionally been quiet about what we do,” said Brittney Keough, PaR’s marketing administrator. “But no more. We are getting the word out.”

Other presenters showing off their technological might at the show included Recon Robotics. Its dumbbell-shaped remote control cameras can safely zig, zip and zag around dangerous environments without risk to police or military personnel. Recon Robotics had products in Iraq and Afghanistan and is now in 30 countries. The company recently sold goods to police departments in Illinois, London, Paris and the Olympic security team in Sochi, Russia, said Binaya Acharya, a Recon marketing leader.

While security robotics were a hot topic at the show, the longest lines were found at the booths of the University of Minnesota and the Japan External Trade Organization (JETRO).

JETRO showcased Paro, a $5,000 seal-like robot that was so laden with sensors that it snuggled, wiggled, nuzzled or wagged with each caress or tickle offered by conference-goers. The secret? Motion or light sensors in the nose, whiskers and body, explained JETRO’s Robert Corder.

The University of Minnesota booth featured robotic boats armed with Asian-carp-spotting transmitters and two human-shaped robots that sat up, bowed, walked and followed a small red ball around the room. The 20-inch-tall robots established eerie eye contact with each passer-by.

“Those are sexy little guys,” said conference worker Ann Turner with a chuckle as she circled one of them. “Oh, my gosh, look. He can see me.”