Forgot your password?
typodupeerror

Comment: Re:Of course you use force control to run fast. (Score 2) 85

by Animats (#47920041) Attached to: MIT's Cheetah Robot Runs Untethered

Pardon my ignorant question, but how is it a problem to have traction control? Wouldn't it be enough to glue traction strips to the feet or something?

That's like wearing shoes with golf spikes all the time.

Traction control for feet does roughly the same thing as automotive traction control for cars. The basic idea is to keep the sideways force below the break-loose point. This is the down force on the wheel times the coefficient of friction.

For car wheels, the down force is mostly constant. For a legged robot, it changes throughout the ground contact phase So the side force has to be actively controlled and changed throughout the ground contact. It's also necessary to compensate for leg angle.

Legs have an additional option. If a leg has three joints, you can adjust the angle at which the contact force is applied. This is a big win on hills.

I used to work on this stuff in the mid-1990s, but nobody was interested in building legged robots back then. It could be used for animation, but it was overkill for games. I never expected that DARPA would spend $120 million on BigDog. Robotics projects in the 1990s were tiny.

Comment: Re: Car Dealers should ask why they're being bypas (Score 1) 140

by fuzzyfuzzyfungus (#47916055) Attached to: Court: Car Dealers Can't Stop Tesla From Selling In Massachusetts
In addition, Tesla(whether or not you see this as an improvement is a distinct issue, it simply is so) sells cars much more like an enterprise IT hardware vendor sells hardware: at least within the warranty period, there is very much an ongoing interaction between the hardware and the vendor. System health information gets sent directly back, on site techs with specialized parts and firmware get sent out and so on. More traditional car companies are closer to buying a PC: the dealer will offer (often absurdly priced; but available) maintenance; and the vendor may become involved with certain warranty or recall cases; but they are otherwise largely out of the loop, with third parties handling the ongoing interaction with the hardware.

Comment: Of course you use force control to run fast. (Score 5, Insightful) 85

by Animats (#47915427) Attached to: MIT's Cheetah Robot Runs Untethered

That article is written as if that crowd invented running using force control. Of course you use force control. Everybody in the field knows that by now. I patented that 20 years ago. The Scout II robot at McGill, developed by Prof. Martin Buehler, used that approach. Buehler went on to become the designer of BigDog, but never got much public credit for it and quit to work for iRobot.

The key to legged running in non-trivial situations is careful management of ground traction. Traction is first priority, then balance, then foot placement. Historically, everybody worried about foot placement first, but that turns out to be backwards. As soon as you get off flat surfaces with good traction, traction control dominates.

The next unsolved problem in that area is not going fast. It's starting, stopping, and turning fast. Most of the legged robots accelerate very slowly, and don't make abrupt high-speed turns. Big Dog starts by trotting in place, then extending the gait out. Starting fast, stopping fast, and turning fast are all facets of the same problem. You have to take one stride using completely different control algorithms than you use for normal locomotion. That's all I'm going to say about this for now.

Comment: Re:Not much different than the fire starting laser (Score 1) 174

How is blinding someone with a laser worse than killing or maiming them with a bullet?

The assorted 'laws of war' are heavily leavened by what their framers suspect that they can actually get at least some people to agree to; but the overall theoretical foundation always seems to be an attempt to steer weapons in the direction of "Kills outright, or leaves a wound that, if treated, will heal with comparatively limited permanent damage."

It's not an easy standard to maintain(both in terms of convenience, mass-maiming is a hell of a shock to morale and logistics, and engineering, something that will kill if it hits you as designed will likely cause serious tissue damage and/or amputation if it scores a sub-par hit); but it's not really a terribly strange shared desire, from the perspective of the warring European powers of the 20th century that wrote most of them.

Comment: As a layman... (Score 2) 103

I'm fairly out of my depth with this stuff, so this is an honest inquiry: how do the magnetic nanoparticles fit into the equation?

I realize that, once coated with a suitably tailored binding protein, the particles will collect whatever target the binding protein was specified for (presumably this could even be tailored, for any target where a suitably tame binding compound is available), and probably fairly efficiently because of the absurd surface area of nanoparticles.

What I don't understand is the necessity of using the nanoparticles. It was my understanding that, outside of seriously immunocompromised victims, T-cells(and possibly other flavors of phagocytes, I'm fuzzy on the details) are extremely adept at engulfing and destroying foreign bodies, including 'clumps' produced by targets bound to the antigens produced by B-cells. This technique appears to be using a synthetic/introduced antigen(which makes sense if the immune system isn't producing the necessary antigen, or not ramping up production fast enough); but it also introduces the nanoparticles so that the antigen clumps can be magnetically scrubbed from the bloodstream, rather than cleaned up by the T Cells.

What is the peculiarity here that would make introducing the novel clump-scrubbing mechanism necessary and worthwhile?

Comment: Clueless (Score 1) 59

by Animats (#47911665) Attached to: New Data Center Protects Against Solar Storm and Nuclear EMPs

This keeps coming up. The effects of an electromagnetic pulse and a solar storm are completely different. EMP is a big RF pulse with a risetime in the nanoseconds. This is a risk to input transistors connected to external wiring. Twisted pair, coax, and small mobile devices are relatively immune. Fiber optics are totally immune.

Solar storms induce DC voltages across long distances of conductive landscape. This is a risk only to transformers with grounded center taps connected to long transmission lines.

Here are the PJM power grid emergency procedures for geomagnetic events. They had to be implemented for a day two years ago. Almost nobody outside of power grid operators noticed.

Comment: Re:Not much different than the fire starting laser (Score 5, Interesting) 174

The Protocol contains a loophole large enough to drive a truck through, never mind some photons:

"Article 3 Blinding as an incidental or collateral effect of the legitimate military employment of laser systems, including laser systems used against optical equipment, is not covered by the prohibition of this Protocol."

As long as the blinding is a side effect (mitigated by "all feasible precautions to avoid the incidence of permanent blindness to unenhanced vision") of a non-blinding purpose(setting things on fire, destroying machine vision/optical sensor gear, 'dazzling', and basically anything else you might feel like using a laser for, it's all legal. That is not exactly fertile ground for any sort of serious arms control, even if lasers weren't comparatively cheap and trivial to build, especially at the modest powers that will really boil your eyeballs but aren't subject to the engineering challenges of aspirational air-defense and antimissile systems.

It gives me no pleasure to say so; blinding is a pretty ugly thing to do; but the Protocol as written is about as effective as forbidding murder; but making it legal to put a bullet through any hat you see, regardless of whether it contains a head or not.

Comment: VPN is the only way to go, for those who care (Score 1) 400

by m.dillon (#47909791) Attached to: Comcast Allegedly Asking Customers to Stop Using Tor

I read somewhere that not only was Comcast doing their hotspot crap, but that they will also be doing javascript injection to insert ads on anyone browsing the web through it.

Obviously Comcast is sifting whatever data goes to/from their customers, not just for 'bots' but also for commercial and data broker value. Even this relatively passive activity is intolerable to me.

Does anyone even trust their DNS?

Frankly, these reported 'Tor' issues are just the tip of the iceberg, and not even all that interesting in terms of what customers should be up in arms about. It is far more likely to be related to abusing bandwidth (a legitimate concern for Comcast) than to actually running Tor.

People should be screaming about the level of monitoring that is clearly happening. But I guess consumers are mostly too stupid to understand just how badly their privacy is being trampled.

There is a solution. Run a VPN. If Comcast complains, cut the T.V. service and change to the business internet service (which actually costs less).

-Matt

Comment: Only Apple can't make sapphire work. (Score 0) 201

by Animats (#47903731) Attached to: Sapphire Glass Didn't Pass iPhone Drop Test According to Reports

Everybody who gets an iPhone immediately puts it into a rugged, generally rubberized, case.

That's pathetic. All that effort to make a super-thin device, and you have to put it another case to protect it. Nokia would laugh.

Get a non-toy phone.

It's amusing that Apple can't get sapphire-coated glass to work. Sapphire glass for checkout scanners is a standard product. Every Home Depot checkout scanner has sapphire-coated glass. People slide metal tools across those for years without damage.

Comment: Voice operation of smartphones sucks (Score 1) 323

by Animats (#47900405) Attached to: Technological Solution For Texting While Driving Struggles For Traction

The smartphone crowd assumes they own the user's eyeballs. They don't. What's needed is better voice integration. You should be able to call, receive calls, text, and receive texts via a Bluetooth headset with the phone in your pocket.

Android sucks at this. My Samsung flip-phone had better voice dialing than my Android phone. Wildfire, which is from 1997, did this quite well. But it was really expensive to do back then, and was priced as high as $250/month. Then Microsoft bought Wildfire and abandoned the product.

Comment: A secular morality that once was popular in the US (Score 4, Interesting) 863

by Animats (#47900281) Attached to: Why Atheists Need Captain Kirk

Business used to have a completely secular moral compass. Rotary International has their The Four-Way Test, a "nonpartisan and nonsectarian ethical guide for Rotarians to use for their personal and professional relationships." Rotarians recite it at club meetings.

Of the things we think, say or do

  • Is it the TRUTH?
  • Is it FAIR to all concerned?
  • Will it build GOODWILL and BETTER FRIENDSHIPS?
  • Will it be BENEFICIAL to all concerned?

This is a morality for business. That's a concept that sounds archaic today. It was mainstream from about 1940 to 1975. Many small business owners used to belong to Rotary, especially in small towns. What went wrong? That's a long story, and has to do with the decline in the political power of small business.

Anyway, that's a completely non-religious moral system which is still around and once was mainstream.

Comment: Re:A solution in search of a problem... (Score 1) 323

It's also an overcomplicated solution. OBD can get pretty nasty if you want access to esoteric stuff or manufacturer proprietary crap; but a basic, bluetooth-capable, OBD dongle that'll report the rough outlines of how a vehicle is being used is quite cheap indeed and not especially complex. I wouldn't necessarily want to try dead-reconing with nothing but that output; but answering "Am I driving right now?" is considerably less demanding.

1 1 was a race-horse, 2 2 was 1 2. When 1 1 1 1 race, 2 2 1 1 2.

Working...