<div dir="ltr"><div dir="ltr"><div dir="ltr"><div>John,</div><div> I am still working through your message, however I have some thoughts and possible answers.</div><div><span style="white-space:pre"> </span></div><div>First a few questions, I know bats have large ears, but in the scheme of things they are small animals, so their sensors (i.e., ears) are no larger than 2x4 inches each. They use a high pitch or ultrasonic squeak (emitter). They also carry their emitter and receivers on their body without any non-integral body parts hanging about. With this equipment they can easily detect insects flying about. The question, is this detection simply obstacle detection (i.e., I look in the air, I see an obstacle, it moves, therefore it is food.) or is it target determination (i.e., I look in the air, I see a moth not a mosquito). What if the moth is on a tree branch. Can a bat still find the moth? </div><div><br></div><div>Do bats move their ears while listening to form a scan of the reflection?</div><div><br></div><div>The contest challenge is to find specific objects (samples). The environment will be a room with lots of stuff and people in it. Could a sonic system have enough discrimination to identify the target objects? Or would it only be able to detect obstacles. What object characteristics or features could it determine (height, width, density, surface curvature, profile, distance, etc...)?</div><div><br></div><div>How would you return to home base? I assume that you will detect the cone at home base as just an other unique object and drive to it.<br></div><div><br></div><div>Now I have some answers.</div><div><span style="white-space:pre"> </span> </div><div>If the robot base is holding you back, I will offer use of my robot "Falcon". You can find a picture of it a<a href="https://www.dprg.org/fall-indoor-competition-results/"> https://www.dprg.org/fall-indoor-competition-results/</a>. It is the white robot in front of me in the quick trip picture. It is a club robot base with a gated scoop in front. I will make provisions to mount a ~5x6.5 inch deck (or multiple decks) on it for your sensors and electronics. Communication between your electronics and the base will be via a serial port (115200 baud). The robot is capable of dead reckoning navigation. We can work out a interface protocol. My thoughts are your electronics should communicate these basic commands: turn right, turn left, go straight, stop, or drive to x,y location. The gate closes when an object trips a sensor inside the scoop, but you could also command gate position. Currently the robot has a low mounted ultrasonic sensor, and a pixyCAM-1. I can remove the pixyCAM and the ultrasonic sensor can be unplugged. The wheel base is 9.75 inches. So your task would be to construct your gear and place it on the deck. I can laser cut a deck, with mounting holes and mail it to you, or give to you at next meeting. The deck will be made of Masonite. I will provide the robot base software. Let me know it this is acceptable.</div><div><br></div><div>An alternative robot base is the club's turtle robot. It is based on a Roomba. It would be much more work but would provide more deck space. I believe it is a ROS capable robot, but I haven't looked at a while so I don't know the state of its electronics.</div><div><br></div><div>Programming the robot with object locations is a no go. Note that the contest's objects are available for practice and generating learning sets at RBNO every Tuesday.</div><div><br></div><div>Sharing information from a competitor's robot run I believe is also a no go. It seems to me that it would be unfair to other competitors.</div><div><br></div><div>Note the rules say that the robot must carry all the sensors, but computations do not need to be done on the robot, you can use an external computer with some type of radio to communicate the robot. Most folks use WiFi.</div><div><span style="white-space:pre"> </span></div><div>Depending on the object features extracted by the sonic system, I think that AI could be useful.</div><div><span style="white-space:pre"> </span></div><div>Regards,</div><div>Doug P.</div><div><br></div></div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sun, Jan 20, 2019 at 12:46 AM John Swindle <<a href="mailto:swindle@compuserve.com">swindle@compuserve.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><font color="black" size="2" face="Arial, Helvetica, sans-serif">
<div>Ron and Doug,</div>
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<div>I am interested if I can exploit the localizer, repurposed not as beacons. Sound can be used for two unrelated tasks: echolocation and localization. Ironically, echoes are a huge source of errors when doing localization, but echoes are vital for echolocation. The two can be used together if the localizer's echoes are processed as passive sonar. This requires a very clean signal because the echoes are subtle. I've spent most of my time seeking waveforms that are inherently low-noise and low jitter.</div>
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<div>Thanks for noting that sound is used for medical imaging. The speed of sound in liquids is much faster than in air, so for reasonable resolution, the sound must be much higher frequency, and liquids are coupled better, so they conduct those high frequencies. No need to go to high frequencies to do imaging in air, and air just won't couple the high frequencies anyway. Your note reminds me that sonar in air could be processed with tomography software. I looked at that a few years ago and was bewildered by tomography. Worth another look.</div>
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<div>My first thought of the bat bot was a baseball bat pulverizing the return samples, then I realized you meant the animal.</div>
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<div>As usual, I am not very interested in making my own motive platform. If I could get sonar imaging working, maybe someone would host the gadget on their robot. The gadget would be omnidirectional, so it would not be pointed at things. But it would be large, about the size of the cat toys that are big donut rings with a ball captive in the ring, so about a foot in diameter and three inches tall.</div>
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<div>Separately,</div>
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<div>Doug, what's your opinion of programming the robot with the locations of the objects and home base? If that is too much prior knowledge, then how about the idea we discussed briefly: </div>
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<div>Sharing information between robots. Not swarming. Connected-vehicle kinda stuff. Results from a competitor's successful run (or at least success in finding stuff even if it isn't retrieved) would feed that competitor's next run and other cooperating competitors.</div>
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<div>All the talk about AI makes me to look at using it to process the sonar instead of continuing to write my own geometry programs.</div>
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<div>Best to you all,</div>
<div>John Swindle</div>
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