Man versus machine as China shows off humanoid robots in half-marathon

Saturday’s road race involving human runners and a score of robots in Beijing has been billed as a showcase of China’s cutting-edge technology.

Indeed, the robots, and their developers, had much at stake in the high-profile event. If the robots fell, froze or got lost during the widely promoted event, it would be an embarrassment for their developers.

The 13 mile-race, which its organizers said was the first of its kind, was a chance for China to show off the latest state of its humanoids, one of several technology areas at the forefront of the U.S.-China tech rivalry. China has said it wants the country to be a world leader in humanoid robots by 2027. Chinese authorities have lavished support such as subsidies, talent bonuses and tax breaks on robotics companies.

In reality, the race showed both how quickly and smoothly some robots are able to run, but also how far away humanoids still are from being able to mimic human activity.

“Running is a very basic ability of human beings," said Tang Jian, the chief technology officer of Beijing Humanoid Robot Innovation Center, which developed one of the robots, Tien Kung Ultra. “Since we are making humanlike robots, we want to give them as many basic human abilities as possible," which would be critical in eventually deploying them for industrial purposes.

Before the race, thousands of human runners crowded in one lane behind the starting line, many jogging in place to keep warm. The humanoids, separated by fences into another lane from the human runners, stood largely still as they waited for the start.

When a siren marked the start of the race at 7:30 a.m., the human runners dashed and spilled onto the course. But the robots’ starts were staggered by a minute or two each to prevent them from ramming into each other.

The first robot off the mark was Tien Kung Ultra, a 5-foot-9 inches, 115-pound humanoid, featuring a pitch-black head and sporting an orange tank top. Three people accompanied it to help control the robot.

The race was the culmination of months of training for the humanoids, which had to master skills that are innate to humans. They had to navigate the course’s flat and hilly roads and maneuver around six left turns and eight right turns, according to the organizers. Developers had to train the robots to keep their stability and balance to avoid falling over a half-marathon distance.

The cutoff time for the robots was 3.5 hours, meaning that the minimum average speed for the robot runners to finish the race was about 3.7 miles an hour. Developers said humanoid robots typically can operate for no more than two hours on a single charge of their batteries. The faster they run, the shorter the distance they can cover.

Components and parts could easily break while running, so developers replaced plastic parts with metal and used extra-strong—but costly—materials. One company trained their humanoids by connecting the robot to a fitness machine-like metal stand to prevent it from falling, a social-media post showed.

Tien Kung Ultra was developed by Beijing Humanoid Robot Innovation Center, a research institute also called X-Humanoid and formed by robotics firm UBTech, electronics and electric-vehicle maker Xiaomi and the local Beijing government. It could run on average 6 miles an hour and could handle hills, stairs, grass and sand, a profile of Tien Kung Ultra posted online by the local Beijing district showed.

X-Humanoid revamped an existing robot model for the half-marathon. Tien Kung Ultra has longer legs than its original model and is taller by around 4 inches, helping it to run faster, state media reported. The developers also used stronger materials to make the hip joints of the robot and installed a pair of sneaker soles on the robot’s feet to absorb shocks and reduce damage to its legs and feet.

Tien Kung Ultra largely breezed ahead of other robots on the route. It fell once when the battery failed, Tang said. The robots were allowed to swap batteries, and Tien Kung Ultra changed its battery three times.

While many robots were directed by a remote control, Tien Kung Ultra used wireless tracking technology that allowed it to communicate with a person running in front of it. An algorithm determined the precise distance needed between the human being and the humanoid, Tang said.

Besides Tien Kung Ultra, there was Xiaowantong N2, or Little Rascal N2, a 4-feet, 66-pound childlike robot developed by Noetix Robotics. At 5 feet 6 inches, Huanhuan was the only one with a head resembling a human. Another robot called Shennong had propellers.

Some were steady and well balanced while others walked—barely. Some never made it much further beyond the starting line. Huanhuan wobbled, at times heading in the wrong direction, then ended its race quickly by sitting down on the course and refusing to go further.

Shennong was particularly disastrous, swinging wildly just after the start, causing the human support runner who was trying to control it to trip. The robot slammed into a fence, breaking into pieces. The marathon staff dashed to clear off the remaining pieces; Shennong’s arm dangled as it left the course.

The human male champion completed the race in one hour, two minutes and 36 seconds, followed by thousands of exhilarated human runners. Some were exhausted, resting nearby to catch their breath.

After two hours, 40 minutes and 42 seconds, Tien Kung Ultra was the first robot to reach the finish line. A large crowd of spectators, including government officials, was eagerly awaiting the robots. Many surrounded Tien Kung Ultra to take photos. The robot maintained its blank expression.

In the end, no other robots were able to meet the cutoff time, when also considering the penalty times they received. Little Rascal N2 and its sibling model Xuanfeng Xiaozi N2—or ‘Whirlwind Kid’—were among the robots that followed, state media showed. While team Tien Kung stuck with one robot throughout the race, others switched robots.

Hang Qian, a 29-year-old Beijing resident who ran the half-marathon, said he beat Tien Kung Ultra by about 10 minutes.

“For ordinary people, a half marathon is an extremely challenging sport and everyone gets exhausted. But robots can continue on by replacing the battery," Hang said.

“In the future, there could be robots competing in cooking, rock climbing or swimming," he said. “I’m looking forward to them all."

Write to Yoko Kubota at yoko.kubota@wsj.com and Raffaele Huang at raffaele.huang@wsj.com