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Initially I will use two different sensors for obstacle avoidance. lidar for closer range 2D image of space (obscale avoidance, scanning ground before landing, maybe SLAM)

and laser rangefinder for long range 1D distance sensing (looking for high buildings, maintaining altitude precisely, maybe high speed obstacle avoidance)

I went with cheapo robopeak hobby lidar, which seems to work well, here is a git repo for the library (node and beaglebone) (I also considered a lightweight hokuyo lidar) and for laser range finder I'll go with something like SF02 from paralax

these might be used in combination with some simple IR or just cameras (need more CPU but could double as optical flow sensors) used to locate becaons for landing or grabbing things

Ideally, both sensors should have an unobstructed front view on pitch dimension, with aditional unobstructed jaw dimension for LIDAR. Both sensors need to be able to independantly rotate on pitch axis for compensation of the angle of the drone when flying, and for scanning up and down (going in through windows, looking down when landing, etc) maybe rangefinder should also rotate on jaw axis on some fast servos for looking around independant of the drone orientation. not sure yet.

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IR and ultrasound were also options, they are cheap but tricky and unreliable, (ultrasound behaves extra badly due to propeller noise on drones) These things can be compensated for, but laser rangefinding will always afaik give more accuracy and reliability at a price.

Thu Oct 09 2014 14:31:52 GMT+0200 (CEST), 50 months ago

repository

I'm surprised I couldn't find this..

async object or json pattern matching/validation used for validating function/process arguments, api call permissions, messages, etc. supports serialization/deserialization of patterns themselves, which I used to implement a generic db query language on top of this. for now, tests are documentation

extras repository contains cuter things like

  • translation of subset of validator patterns to mongodb queries
  • validated backbone models (model that throws if certain attributes aren't set or if doesn't find appropriate superclass (for mixins))
  • validated backbone model attributes (special accessors that validate the data before its written to a model)
Fri Sep 13 2013 10:35:14 GMT+0200 (CEST), 62 months ago

generic communication framework

repository

uses a few of my libs like nodejs-graph, nodejs-subscriptionman, nodejs-validator2 and others

  • consists on bunch of interconnected nodes that can subscribe and answer to/filter/translate JSON mesages, kinda like actors but not really.
  • has network transparency and supports arbitrary transport protocols (http, websockets, tcp, tls, REST have been implemented for now)

I've implemented some protocols above this, like

  • live object syncing with a permissions model
  • database agnostic collections and object persistence
  • ongoing auto updating database queries

I use it for all kinds of things, like

  • web applications (clients and servers are running a simmetric code),
  • different distributed complex infrastructures
  • random things, my laptop is using it to watch and react to system wide events, like lid being closed or connection to the internet being established, my cellphone is running it in order to connect and sync with my computers and it is what I use to control lights in my appartment or display data from remote servers on my desktop

and I've built a few libs on top of this

Tue Sep 10 2013 07:07:06 GMT+0200 (CEST), 63 months ago