Robots that can walk are now striding to market


They will be able to go where people can, but existing bots cannot


They might appear cutesy, but a pair of robots that turned up recently at the Ford Motor Company’s Van Dyke Transmission Plant, in Detroit, are practical working machines. They may, indeed, point to the future of automation. Putting robots into factories is hardly a new idea—some 2.4m of them are already at work in plants around the world. But most of these are little more than giant arms, bolted firmly to the ground, that weld and paint things. Those few that have the mobility to manage tasks like delivering components do so by scooting along on wheels. The new devices at Van Dyke are rather different sorts of beasts. They can walk.

它们可能看起来忸怩作态,但最近位于底特律市福特汽车公司的Van Dyke变速器制造工厂出现的一对机器人是实用的作业装置,它们可能标志着自动化的未来。让机器人走进工厂不是什么新理念,已经有约240万台机器人在世界各地的工厂里工作,但多数是用螺栓固定在地面的巨大机械臂,用来完成焊接和喷涂工作。少数具有机动性的机器人被用来完成运送零部件等任务,依靠轮子在地面滑行。出现在Van Dyke工厂里的新装置截然不同,它们能够行走。

Over the years, factory plans get out of date as things are moved around and new equipment is brought in. Surveying the transmission plant by hand would take weeks and cost some $300,000. Ford reckons that Fluffy and Spot, which can both climb stairs and crawl into hard-to-reach areas, will cut the time required by half and complete the job for “a fraction of the cost”. Although Ford is leasing the robots, Boston Dynamics has now put them on sale for $75,000 a pop. At that price they would soon pay for themselves doing tasks like the one being undertaken in Van Dyke.

多年以来,随着物品的四处搬迁和新设备的引进,工厂的规划已经过时。人工测量变速器制造工厂耗费数周时间,耗资三十万美元。 “毛绒绒”和“斑点”都能爬楼梯,钻进人类难以到达的地方,福特汽车公司估算这能节省一半时间,耗费“一小部分成本”就能完成任务。尽管福特汽车公司在租用这些机器人,但波士顿动力公司现在也出售它们,售价为每台75000美元。如果被用来完成Van Dyke工厂那样的任务,这个价位很快就能回本。

The Spot range is the first of Boston Dynamics’s walking robots to be commercialised. More such machines are starting to appear from other firms and research groups. Some are also quadrupeds. Others are bipedal. The two-legged sort can be more agile and, if equipped with arms as well, are better suited to tasks like picking things up or operating controls. What all of these machines have in common is that they represent—forgive the pun—a huge step forward in robot locomotion.


Four legs good, two legs better


If robots are to go where people go, they need to be able to move in the way that people move. Wheels are useless for navigating much of the world—just ask anyone who uses a wheelchair, says Aaron Ames, a robotics expert at the California Institute of Technology (Caltech). “We can make robots walk really well now,” he says. Such robots can, though, look a little odd. When a torso with two legs attached strolls out of Dr Ames’s laboratory it causes a bit of a sensation on Caltech’s campus. But this is something people are going to have to get used to, because many more are coming.


Problems remain, and improvements are needed. “But once we get there, we are going to have millions of walking robots in human environments,” says Jonathan Hurst, co-founder of Agility Robotics, a firm based in Albany, Oregon. It has just launched Digit, a bipedal, two-armed robot which has the look of an ostrich about it. At present, Digit costs $250,000. But it is early days. As more walking robots are put to work their development will accelerate and their production volumes increase, bringing the cost of a machine like Digit down to the tens of thousands of dollars.


This process is similar to the emergence of flying drones. They once cost millions, and had limited uses, until researchers worked out how to make small aircraft hover using multiple co-ordinated rotors. These devices could fly easily and autonomously. Prices fell to $500 or less, and multi-rotor drones are now employed for all manner of jobs, from cinematography to aerial surveying to delivering packages. Some in the field of robotics think walking robots have started down a similar path.


Stroll on!


The way that humans walk is sometimes described by biomechanists as controlled falling. Making a stride involves swinging a leg out and placing it down with small subconscious corrections to maintain stability as the mass of the body above it shifts forward. Each leg works like a spring. These movements are predictable, and in recent years researchers have found out how to model them mathematically. Together with better actuators to operate a robot’s limbs, and sensors which can measure things more accurately, these models have made it possible to recreate this style of walking in robots. It does not require any fancy machine learning or artificial intelligence to do so, just good old-fashioned computation, adds Dr Ames.


The difference between Asimo’s gait and that of the new breed of bot is striking. Whereas Asimo’s chunky legs look leaden, Digit strides confidently along on a lean pair of limbs, happily swinging its arms as it goes. Atlas (pictured), an experimental humanoid made by Boston Dynamics, is more capable still. It can walk, run, jump and even perform backflips. Asimo did a lot of celebrity photo-opps, but it never went into production. Honda quietly stopped work on the project in 2018, to concentrate on more “practical” forms of robotics, such as mobility devices for the elderly.


Another example of art evolving to imitate nature occurred during the design of Digit. This inherited its ostrich looks from Cassie, a two-legged torso which Agility sold to a number of research groups. Cassie’s developers had to find a way to stop some of the robot’s actuator motors from working against each other. Their solution turned out to look like a pair of bird’s legs.


The arms can perform other useful tasks, too, such as moving boxes in a warehouse. Digit can carry up to 20kg. Distributing and delivering goods is likely to be an important application for walking robots, reckons Dr Hurst, especially now that e-commerce has boomed as a result of restrictions imposed in the wake of covid-19. Some automated distribution centres are set up for conventional fixed and wheeled robotic systems, but these have usually been built this way from scratch. Most warehouses are designed around people. Robots with legs, which move in a similar way to human workers, would fit right in.


Exactly how this might be done remains to be seen. Unless they are on a preprogrammed mission, most mobile robots require an operator to provide basic instructions to, say, proceed to a certain point. The robot then walks there by itself, avoiding obstacles and climbing or descending steps and stairs along the way. This means a walking robot making door-to-door deliveries might need some kind of digital map of the neighbourhood, to know in advance the paths it can traverse and the flower beds it should avoid. That might involve a big data-acquisition effort, much like those used to build digital maps for driverless cars. Similarly, in a factory or a warehouse, a walking robot would need to be shown the ropes by a human being before it was let loose to work on its own.


Self determination


In the meantime, the new generation of robots now being developed will keep building up the machines’ capabilities. At Boston Dynamics Mr Perry reckons that, besides surveying, Spot will find many roles in inspection and maintenance. Such robots can, for instance, enter hazardous environments like electrical substations without them having to be taken off the grid, as is necessary whenever a human engineer goes inside.


Instead of just looking for problems, Spot’s next trick will be to take action to resolve them, such as throwing a switch or turning a valve. It will do this with a single manipulator arm which makes it look less like a dog and more like a long-necked Brachiosaurus. A prototype of this configuration is already running around the company’s offices, opening and shutting doors.


This version of Spot should go on sale next year. As for Atlas, Boston Dynamics’s humanoid, that is currently too expensive to spawn a commercial version. But the lessons being learnt from it will help provide the engineering needed for other robots to come, says Mr Perry.