31–40 of 56 posts
Finally, as I get my proteins denatured by a quadruped-mounted face-finding energy weapon in Civil War II, I can go out singing Stallman's song. You will be free, hackers. You will be free
Energy weapons are expensive to build. Chemical weapons are cheap. The War of the Machines is going to be all nerve gas, all the time. :(
Earlier quoted context omitted.
As a robotics platform, there's nothing inherently weaponizable about quadrupedal locomotion over, say, a quadcopter. Weaponizing this system would be almost as difficult as developing and then weaponizing the system.
State actors already have the weapons, so it is not complicated to attach those to a tool capable of ferrying them over rugged terrain, with long battery life, and into hiding places of human opponends. Just as they attached them to drones, cars, and other gear. What guarantees that the biggest use cases and the most motivated users of this technology are not deadly? Maybe license?
Boston Dynamics robot with gun: Quote: "At the Association of the US Army’s annual conference last week, Ghost Robotics unveiled its Vision 60 quadrupedal robot, which wielded a custom-made gun atop its already eerie figure."
https://www.extremetech.com/extreme/328299-robot-dogs-now-fi...
Very nice. What makes this work is the motors.[1] It's using 3-phase drone prop motors with no gear reduction. With direct drive, the mechanics of the joints are simple. Not too expensive, either. Each motor is about US$120. I used to work on legged running back in the 1990s. But there were no motors good enough to build a small machine like this back then. All we had were R/C servos, gearboxes, and screw drive actua…
A lot.
I've broken a half dozen mounts, ripped a circuit board in half and smoked a few passives in the process. My recommendation is to start with a small motor when you're tinkering with this stuff haha.
(I'm no expert but super happy customer of mjbots btw)
Very nice. What makes this work is the motors.[1] It's using 3-phase drone prop motors with no gear reduction. With direct drive, the mechanics of the joints are simple. Not too expensive, either. Each motor is about US$120. I used to work on legged running back in the 1990s. But there were no motors good enough to build a small machine like this back then. All we had were R/C servos, gearboxes, and screw drive actua…
What do you think about these direct linear actuators [0]? They seem super simple, and like a closer match to the way biological muscles work. Is there some reason why rotary (?) actuators are the default choice for robotics? Edit, also what happened that made electric motors so much better since the 90’s? It’s not like we made groundbreaking discoveries about magnetism, right? [0] http://moticont.com/direct-drive-li…
Earlier quoted context omitted.
As a robotics platform, there's nothing inherently weaponizable about quadrupedal locomotion over, say, a quadcopter. Weaponizing this system would be almost as difficult as developing and then weaponizing the system.
State actors already have the weapons, so it is not complicated to attach those to a tool capable of ferrying them over rugged terrain, with long battery life, and into hiding places of human opponends. Just as they attached them to drones, cars, and other gear. What guarantees that the biggest use cases and the most motivated users of this technology are not deadly? Maybe license?
If you're worried about weaponization of open source projects, your threat actors are just about any person with a computer, a couple thousand dollars and a grudge.
Very nice. What makes this work is the motors.[1] It's using 3-phase drone prop motors with no gear reduction. With direct drive, the mechanics of the joints are simple. Not too expensive, either. Each motor is about US$120. I used to work on legged running back in the 1990s. But there were no motors good enough to build a small machine like this back then. All we had were R/C servos, gearboxes, and screw drive actua…
That said, for the kind of work ANYmal is currently being deployed on (site inspection mainly, I believe), they're hardly doing hyper-dynamic movements, so I think selecting SEAs over quasi-direct drive was a fairly judicious choice. Just like it makes more sense to have quasi-direct drives in a highly dynamic robot like the MIT Cheetah; it depends on the use case.
[1]: https://www.researchgate.net/figure/Comparison-of-EV-electri...
I have an tangential question about open source projects and names. "Boston Dynamics" is a trademark of Boston Dynamics Inc. Can using "Dynamic" like this project does cause legal problems, considering the name can be an allusion to the trademark?
Should weapons be open sourced?
I'm sure there's a lot more philosophical depth to the topic, and perhaps my quick dismissal of your criticism is equally unproductive as your comment, but I see a use-case for these (frankly super cool) robots in every day society/workplaces.
[1]: https://www.subtchallenge.com/results.html [2]: https://www.engadget.com/robot-dog-gun-ghost-robotics-sword-...
Very nice. What makes this work is the motors.[1] It's using 3-phase drone prop motors with no gear reduction. With direct drive, the mechanics of the joints are simple. Not too expensive, either. Each motor is about US$120. I used to work on legged running back in the 1990s. But there were no motors good enough to build a small machine like this back then. All we had were R/C servos, gearboxes, and screw drive actua…
What do you think about these direct linear actuators [0]? They seem super simple, and like a closer match to the way biological muscles work. Is there some reason why rotary (?) actuators are the default choice for robotics? Edit, also what happened that made electric motors so much better since the 90’s? It’s not like we made groundbreaking discoveries about magnetism, right? [0] http://moticont.com/direct-drive-li…
When using a linear actuator, you need to offset it from the joint so that it generates torque (that's part of the reason we have kneecaps, actually; it increases the distance between the centre of rotation of our knee and where our leg muscles are actually pulling from, increasing the output torque). This involves more mechanical complexity in the design compared to rotary actuators, which can just be slapped onto the joint directly. That offset also takes up space, so your system is now less compact.
None of the heavier legged robots I know of use direct drive actuators; ANYmal uses Series Elastic Actuators, MIT Cheetah and (maybe) Boston Dynamics Spot use Quasi-Direct Drive actuators with a low gear ratio gearbox (sub-10:1, I believe), RealHyQ uses hydraulic actuators. Electric actuators simply can't output the amount of torque these systems need to carry themselves around, so they need some form of gearing. The linked actuators you shared are direct driven, so they would need some gearing on their output. I had trouble finding anything about gearing direct drive linear actuators, which leads me to believe it's not really a thing, because if you need high loads, you'll jump to geared linear actuators, which are really just rotary actuators with a belt or rack and pinion!
Aside from the mechanical challenges associated with using a linear actuator setup, it's (to my knowledge) not necessarily better to follow biology when it comes to robots. Wheeled robots can move faster on flat terrain than any animal, so legs aren't ideal when you have access to gas-powered engines or electric actuators. Airplanes with turbines can carry much heavier loads than birds because flapping wings just doesn't scale up to the weight of a jumbo jet with luggage and passengers. Legged robots are actually more energy efficient when they don't try mimicking an animal's gait because they don't have organic muscles arranged in the same way. Any finally, rotary actuators are a better choice than linear actuators (for now) because we don't have hyper-compact, super torque-dense linear actuators that can match our muscles.
This isn't to say that biologically inspired designs can't be better, and there's a lot of research into finding ways of replicating the natural properties of certain materials, such as the strength of silk or hardness of the shells of some crustaceans. But in the end, with the technology we have, rotary actuators provide better torque density, and a more compact and simple design than linear actuators.
[1]: I didn't cite anything here because of time constraints, but it's an amalgamation of half-forgotten knowledge from some research I've done on the topic of legged robots