Islander Posted June 27, 2009 Share Posted June 27, 2009 It's not really a dog, it's a four-legged pack robot that can carry a heavy load and walk across almost any kind of terrain, unlike the wobbly robots we've seen so far. A guy tries to kick it over and it keeps its balance. It doesn't even fall when it skids on some ice. This could be a very useful machine. Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted June 27, 2009 Share Posted June 27, 2009 Islander. thanks for the link. that is amazing, absolutely amazing technology. sort of creepy to watch, too. Quote Link to comment Share on other sites More sharing options...
Islander Posted June 27, 2009 Author Share Posted June 27, 2009 At first glance, the funny legs and big packs at the corners make it look like a giant wingless fly and that is pretty creepy. Then the legs started to look like the legs of two men facing each other carrying a sofa while wearing shorts, so that's just a bit odd. The way it reacted to being kicked and to slipping on the ice was so much like a real creature that it actually made me feel sympathetic toward the machine. Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted June 27, 2009 Share Posted June 27, 2009 yes. i noticed the appearance of the legs facing each other, knee to knee. the recovery after being kicked and slipping on the ice was uncanny in it's resemblance to a live creature. unbelievable. I would love to hear one of the engineers describe (in lay terms) the software and sensors and motors which drive the thing. Quote Link to comment Share on other sites More sharing options...
Islander Posted June 27, 2009 Author Share Posted June 27, 2009 Is no-one else curious about this very impressive demonstration of robotic technology? It looks like it could have a lot of practical applications. Quote Link to comment Share on other sites More sharing options...
customsteve01 Posted June 28, 2009 Share Posted June 28, 2009 That is really cool. But they need to do something about the buzzing noise. Steve Quote Link to comment Share on other sites More sharing options...
Islander Posted June 28, 2009 Author Share Posted June 28, 2009 It sounds like it's powered by some kind of two-stroke engine, which would be the lightest power available. It seems to be a prototype, so the production model could be somewhat different, maybe with electric power. Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted June 28, 2009 Share Posted June 28, 2009 I watched it with the sound off. Didn't want to bother the wife. Thinking about it now, I'm wondering if the engine just powers a hydraulic pump or drives a generator. Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted June 28, 2009 Share Posted June 28, 2009 all we need is more buzzing two-cycle engines. I already live in the land of weed-wackers and leaf blowers. No thanks. Quote Link to comment Share on other sites More sharing options...
oscarsear Posted June 28, 2009 Share Posted June 28, 2009 Neat and very interesting but it is useless in combat. You may not be able to kick it over but an RPG or such could stop it easily. Maybe for resupply of remote places I don't know. Obviously useful if you want to explore dangerous rough terrains like inside volcanoes. Quote Link to comment Share on other sites More sharing options...
pauln Posted June 29, 2009 Share Posted June 29, 2009 I did this stuff in grad school many moons ago... Systems like this commonly use a hierarchy of negative feedback control loops. Each loop has a comparator that receives both a reference signal from the level above and an input signal from the level below. The input signal includes any disturbance encountered and the comparator subtracts the input from the reference signal. At the lowest level, this input and disturbance signal is from the sensors in contact with the outside world. The sensors measure a "controlled quantity" in the lowest level, the higher levels' controlled quantities are the weighted inputs from the multiple loops in the level below. The comparator subtracts the input signal from the reference signal and that difference becomes the output. This is the basis of the negative feedback loop which tends to correct the output to drive the input (error signal) to minimum, and in so doing takes into account automatically any additional disturbance to the input. When these loops are stacked in a hierarchy, the outputs of an upper level becomes the reference signal to the lower level, and the inputs to the comparator of the lower level (multiple inputs from a bunch of them) are paralleded to the input of the next upper level. The lowest level in the hierarchy may only control something simple like the tension or force in a segment of a leg structure. The next level "up" may then use the multiple inputs from below to provide a reference signal to the lowest level that might be interpreted as a configuration or shape or position. The next level up might control the change from one shape or position of the leg to another (movement), and the next level up might coordinate a series of movements or patterns, and on and on... like the difference between walking and running, turning, jumping, etc. This allows the top level to respond to a strategic instruction like, "Move from here to over there" and the tactical details are taken care of in the levels below. This is why the disturbances are corrected and why the robo dog was able to recover from being kicked over. This hierarchy of control systems is used all the time when a thing needs to move "smartly" as in industrial robots, fly by wire aircraft controls, and is also the underlying design for how WE move, too! Oh yeah, the noise may be from the use of stepper motors which are used in lots of control systems. The motors have a set number of positions of rotation or extension an a series of electrical pulses are used to move from one rotation or extension position to another. The motor may have hundereds of individual positions, and the noise comes from it responding to each of the high speed signals to move it through each of those steps real fast, one by one. By the way, if you have a Firefox browser, type this into the address line and hit enter... about:robots ... it will surprize you. A simple two level control system hierarchy might look like this: Quote Link to comment Share on other sites More sharing options...
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