He just couldn’t stay away. Aaron Edsinger, the former Director of Robotics at Google (2013-17), is back with another mobile manipulator. After three years in stealth mode, Hello Robot co-founders Edsinger and Charlie Kemp unveiled Stretch, a slender robot looking to flip the script on what we’ve come to expect from mobile manipulators.

Founded in 2017, Hello Robot has offices in Atlanta and Martinez, Calif. Kemp is a professor at Georgia Tech and in 2007 founded the university’s Healthcare Robotics Lab. Edsinger sold, for undisclosed amounts, two robotics startups to Google in 2013: Meka Robotics and Redwood Robotics. Meka was developing mobile manipulators, and Redwood was working on robotic arms.

Edsinger and Kemp will be featured on tomorrow’s episode of The Robot Report Podcast, where we learn about Stretch and talk about the challenges and opportunities of mobile manipulation.

Stretch Research Edition

The first version of the robot, the Stretch Research Edition (Stretch RE1), targets academic and corporate researchers. Weighing in at just over 50 lbs., the Stretch RE1 features a Roomba-like mobile base that moves at a maximum speed of 0.6 m/s, an Intel RealSense D435i depth camera with an IMU, a telescoping arm and lift, and a custom gripper that offers a 3.3lb payload.

The arm can reach up 43.3 inches high and extends outward 20.5 inches. The Stretch RE1 also features torque sensing in all its joints to detect contact, a laser range finder, an onboard computer, and differential two-wheel drive. The robot has various mount points and expansion ports that allow researchers to extend the robot with their own hardware.

The software for the Stretch RE1 is all open source. It includes a ROS interface with a calibrated model of the robot. Stretch RE1 includes an open-hardware library of accessories that researchers can 3D print, such as a tray with a cup holder for delivering objects and a phone holder that can be used to take pictures.

For those who don’t want ROS, there’s also a low-level Python layer, which handles the robot’s local teleoperation skills via the included Xbox controller. Kemp tells a great story on this week’s podcast about how he remotely teleoperated an earlier version of Stretch to take care of the family cat while on vacation. He used web-based teleoperation code they’ve released as open source.

“You may think Stretch is just for hardcore roboticists, but we’re hoping to change who uses robots,” said Edsinger. “We have one customer who might only teleoperate Stretch for human factors studies.” Stretch can operate fully autonomously, too. Check out this spec sheet for a full breakdown of the Stretch RE1. Below is a video compilation of autonomous demos from the Stretch RE1:

Priced at $17,950, the Stretch RE1 is significantly more affordable than other mobile manipulators currently available. Three- and six-packs of Stretch RE1s are available for $49,950 and $98,950, respectively. For the sake of comparison, Edsinger’s M1 mobile manipulator cost about $340,000 in 2011.

“Once grad students got laptops and could work from home, productivity went up. We hope Stretch will pave the way to one robot per researcher,” said Kemp. “I’ve always wanted one robot per student. If you’re time-sharing a robot, your productivity goes down.”

Think of the Stretch RE1 as a means to democratize the advancement of mobile manipulators. “We see Stretch as an invitation for a much larger community to become involved with mobile manipulation. We’re excited to see the new applications it unlocks,” said Edsinger.

Bootstrapping Hello Robot

While they did take meetings with potential investors, Edsinger and Kemp said they decided to self-fund Hello Robot. “The things we would’ve had to commit to, particularly given the cost of bringing hardware to market, would’ve almost guaranteed our failure,” said Edsinger. “We just recognized it was the wrong model for our early stage hardware startup. It’s worked out very well for us so far, and it has allowed us to retain control of the company.”

Despite Hello Robot likely being better positioned than other startups to take the self-funded approach, both of its founders have a bootstrap mentality.

“There are dead bodies of venture-backed robot companies everywhere,” said Kemp. “We’re doing small production runs because it allows us to scale in a smart manner. We are able to be profitable and driven by customer demand from the beginning. That’s a great place to be.”

Edsinger said the initial plan was for Hello Robot to be larger scale and sell directly to consumers. But the team received sage advice. “Generally, we found there’s a mismatch between an investor’s business model and where the technology is today,” said Edsinger.

Edsinger and Kemp have known each other for years, going back to their days studying under Rodney Brooks at the Massachusetts Institute of Technology (MIT). The two continued to collaborate throughout the years – Kemp’s lab purchased one of the first M1 mobile manipulators from Meka Robotics – and plan to keep the team small, for the time being.

“Between Charlie and me, we’re pretty full stack. So we don’t have to hire a giant team,” said Edsinger. “It makes problem-solving and decision-making very efficient. At Google, I remember one meeting where we had to make a big decision with 12 people in the room. The outcome of the meeting was a plan to have another meeting.

“At Hello Robot, we’re on generation eight of Stretch’s design. At one point we knew the sixth-generation design wasn’t going to work. And within one day we re-routed the whole plan and didn’t get bogged down by the structure of the organization.”

A glimpse into the future

Thanks to its 3D perception and compliant gripper, Hello Robot in its launch video shows the Stretch RE1 autonomously navigating a home and picking up a variety of objects, including an egg, spoon and its own Xbox controller, off a variety of surfaces. It also shows the robot autonomously opening a drawer and cleaning a table.

The gripper’s springs conform to the object it’s trying to grasp, while rubber fingertips achieve high-friction contact. The gripper’s Python interface provides motor current and position feedback as approximations of grip pose and grip force.

The launch video also shows the robot being tele-operated to play with a dog and vacuum a couch. At the moment the robot comes with a proprietary gripper, but there is an open hardware tool share option that allows customers to explore different attachments.

The current version of Stretch is “very much a robot for researchers,” but Hello Robot has more lofty long-term goals in mind. The video is a glimpse at how Hello Robot hopes future versions of Stretch will be used: at home, by everyday people, to perform everyday tasks.

“Human assistance is a longer-term goal, but we started in the research segment pragmatically,” said Kemp, who has conducted extensive research throughout his career on the use of assistive robots. “I have a model of a person in a wheelchair, so we used that when we came up with the dimensions and the design of Stretch.

Hello Robot wouldn’t name any of its early customers, but it said the first people it contacted are leading researchers in assistive robotics and home robotics. Hello Robot is licensing the design of the Stretch RE1 from Georgia Tech.

“We’re excited for researchers to help us make the future of mobile manipulation fun, useful and inclusive,” said Kemp. “This is a robot for everyone.”