This headless ostrich robot wants to deliver a package to you

Cassie is a mobile, flexible bipedal robot developed by robotics company Agility Robotics that can be used for scientific research, disaster relief, and in the future, cargo transportation.

Today, Agility Robotics, a spinoff of Oregon State University , released a new bipedal robot called Cassie. Cassie is a very flexible bipedal robot that looks more like a flexible human than the heavy-footed bipedal robots we have seen in the past. This allows Cassie to better handle complex and diverse terrains that humans can walk effortlessly. The intelligence it possesses can help people deal with different environments and situations, and this intelligence is a must for future robots.

In addition to search and rescue and disaster relief, Agility Robotics has another very specific use case in mind: They want Cassie to briskly walk up your steps and drop packages off at your front door.

In a demonstration video, Cassie is only three months old. If you look closely at the movement of the robot's legs as it walks, you'll find that its steps are steady, with no noticeable bounce.

In the video, they spared no effort to let Cassie do all kinds of things: walking through mud and grass, it can keep balance on a swaying floating bridge in the water, and it can even stand up in heavy rain. These skills are very important for any robot that wants to survive in Oregon.

Cassie looks more like an ostrich than a person, but not because Agility Robotics specifically designed an ostrich-like robot. They didn't want to simply imitate animal form. They studied animal behavior and movement for design inspiration. The researchers first thought of birds that can run on the ground. Through Agility Robotics' clever design, Cassie's movements have become more agile, efficient, and strong.

This is a necessary test for bipedal robots

Agility Robotics is a new company, but it is a force in the ATRIAS robot. Cassie is a new generation of robots designed based on the full absorption of the ATRIAS project, and its goal is to build a more practical and capable platform. As Jonathan Hurst, co-founder of Agility Robotics (and professor at the University of Oregon) told us:

There are too many unknowns in the design of ATRIAS. ATRIAS is the first demonstration robot that imitates human gait and walks using a spring device. The spring device is used to reduce the reaction force from the ground and maintain the center of mass movement of human gait. But this machine has no practical significance other than just a scientific demonstration.

We learned several key points from ATRIAS: First, the leg structure design of ATRIAS is a 4-link structure, which, to some extent, minimizes the inertia of the spring structure. However, this structure causes one motor inside to hinder the movement of another motor, and a lot of energy is wasted between the internal motors switching repeatedly instead of doing useful work. After careful research and analysis, we designed Cassie's unique leg structure. This leg structure makes the motor smaller and more efficient than the previous ATRIAS.

Cassie has a three-degree-of-freedom hip joint

In addition to being more efficient, Cassie has made various practical improvements based on ATRIAS. Like humans, it has a three-degree-of-freedom hip joint that allows the machine's legs to move forward, backward, and sideways, while also being able to rotate its legs. This new structural design makes Cassie easier to control than the previous ATRIAS. It has a reinforced ankle design that allows it to stand still, without having to keep moving its feet like ATRIAS to maintain balance. It has a large enough battery capacity to run a powerful plug-in computer, which means that various environmental perception systems can be integrated in the future.

Jessy Grizzle, a professor at the University of Michigan College of Engineering, who once opposed the naming of the ATRIAS robot MARLO in the Dynamic Legged Locomotion Lab, was excited about the excellent performance of the first Cassie robot after receiving it. The professor and his students have done laborious tests to confirm that MARLO will not fall when outdoors. "Cassie is very stable," Grizzle told us. "It is designed for uneven surfaces and is used for fall testing. In principle, we should not use any safety measures. This allows us to take the robot outdoors."

At the same time, Agility Robotics began to seek commercial applications for Cassie beyond scientific research. Hurst told us:

If we really know how to design flexible, capable bipedal robots, there will be many applications for such robots in the future, including search and rescue, robotic exoskeletons, powered prosthetic limbs, and mailing packages.

我认为将来双足机器人的市场和汽车工业类似，包括市场规模大小和对社会的影响力方面。我们都想要远程监控机器人，在家庭方面我们需要机器人提供帮助。我们都想要日用品和其它货物能够又快又便宜的送到家门口。我们都希望在贯穿整个生产制造过程中，通过提升物流效率，显著降低货物的制造成本。Cassie 朝这个方向迈进的第一步，它会是卖给研究机构的第一代产品，用来帮助研究者社区解决在人类生活环境中应用双足机器人的问题。Cassie 会持续改进和发展。Agility Robotics 会将焦点放在产品本身和商业客户身上。

Cassie's final design, with protective cover

Hurst told us that robotic arms and various sensors will soon be added to the robot. These sensors will help Cassie stand up on her own after a fall. They also have a remote VR system. As for the cost, the company is reluctant to disclose the specific value, only telling us that their goal is to make a robot with a total price of less than $100K.

The company says the first batch of Cassie units has already sold out. But if you want to buy one to study, wait until the summer. As for using Cassie to deliver packages, it's an interesting idea, and we can see the benefits: the world around us is mostly adapted to human bipedalism, and bipedal robots could be the easiest and most reliable platform for getting things done. There's still a lot of work to be done before Cassie can carry groceries up the stairs for you. But we can't wait to see Cassie do more with bipedalism.