Great article, Avik. Though, I am curious how much mass and volume this cooling system adds to the robot. So you have a choice of using that additional mass + volume budget on cooling or just making the motors slightly larger, which will not only increase their maximum torque/power output but also their surface area and thus cooling ability. Obviously this is probably not sufficient to run a marathon, but there's clearly a tradeoff there, with an inflection point at some duty cycle. The added complexity, cost, and liability of the cooling system is also a sore point.
Relatedly, it would be fun to figure out just how comically large the motors would need to be to run a marathon without liquid cooling or an ice pack. And at that point, how much higher can the robot jump?
All great points, Ben. Yeah, this article started from an assumption of approximate motor size originally made in the prior article https://www.avikde.me/p/honors-humanoid-ran-the-fastest-half?r=5vzx85&utm_campaign=post&utm_medium=web). I think picking a motor mass budget is one of the earlier decisions you have to make in the robot design, because everything seems to scale in mass downstream of that decision. If you're able to fit a larger motor with higher Km, it's definitely better because you reduce not just thermal load, but also can be more efficient. A larger motor is actually relatively much better for jumping than walking (where the repeated swing energy loss penalizes large rotor inertia more).
Hello, my name is Hosein Aslami. I’m a graphic designer, and I’m very passionate about graphic design and creative work. Would it be possible for me to work with you? I would be happy to show you my skills and experience through a project. Thank you for considering me.
Great article, Avik. Though, I am curious how much mass and volume this cooling system adds to the robot. So you have a choice of using that additional mass + volume budget on cooling or just making the motors slightly larger, which will not only increase their maximum torque/power output but also their surface area and thus cooling ability. Obviously this is probably not sufficient to run a marathon, but there's clearly a tradeoff there, with an inflection point at some duty cycle. The added complexity, cost, and liability of the cooling system is also a sore point.
Relatedly, it would be fun to figure out just how comically large the motors would need to be to run a marathon without liquid cooling or an ice pack. And at that point, how much higher can the robot jump?
All great points, Ben. Yeah, this article started from an assumption of approximate motor size originally made in the prior article https://www.avikde.me/p/honors-humanoid-ran-the-fastest-half?r=5vzx85&utm_campaign=post&utm_medium=web). I think picking a motor mass budget is one of the earlier decisions you have to make in the robot design, because everything seems to scale in mass downstream of that decision. If you're able to fit a larger motor with higher Km, it's definitely better because you reduce not just thermal load, but also can be more efficient. A larger motor is actually relatively much better for jumping than walking (where the repeated swing energy loss penalizes large rotor inertia more).
Hello, my name is Hosein Aslami. I’m a graphic designer, and I’m very passionate about graphic design and creative work. Would it be possible for me to work with you? I would be happy to show you my skills and experience through a project. Thank you for considering me.