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beam_robotics [2009-01-08 11:54] – created davegriffithsbeam_robotics [2009-01-09 12:48] – davegriffiths
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 ===Biology, Electronics, Aesthetics, and Mechanics=== ===Biology, Electronics, Aesthetics, and Mechanics===
  
-A design philosophy for robotics, where analogue electronics and reactive sensor control is preferred over digital electronics via a microcontroller and the use of planning AI. +See also [[Robot Building]], [[Robot Design]] and [[Category Robotics]]. 
 + 
 +A design philosophy for robotics, where analogue electronics and reactive sensor control is preferred over digital electronics, microcontrollers or the use of planning AI. BEAM is the invention of robotics physicist [[http://en.wikipedia.org/wiki/Mark_Tilden|Mark Tilden]].
  
 ===Freeforming, Recycling and the use of Solar Power=== ===Freeforming, Recycling and the use of Solar Power===
  
-Another key element of BEAM is the use of 'freeforming' circuits rather than using a conventional substrate upon which to build a circuit, such as a PCB. Components are directly soldered together and become part, or the entirety of the structure of the robot. BEAMer's also prefer to use recycled parts and material in the construction of their robots, and the use of solar power rather than batteries. +A key element of BEAM is the use of 'freeforming' circuits rather than using a conventional substrate upon which to build a circuit, such as a PCB. Components are directly soldered together and become part, or the entirety of the structure of the robot. BEAMer's also prefer to use recycled parts and material in the construction of their robots, and the use of solar power rather than batteries. 
  
 These design restrictions result in some beautifully simple and effective machines. These design restrictions result in some beautifully simple and effective machines.
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 ===BEAM Nervous Networks=== ===BEAM Nervous Networks===
  
-The control mechanism of a BEAM robot is a set of analogue circuits which are broadly biologically inspired, and can be connected together to provide fixed control signals (for tasks such as moving a multi-legged walker) or have sensors integrated into them to provide a link to the outside world.+The control mechanism of a BEAM robot is a set of analogue circuits which are broadly biologically inspired, and can be connected together to provide fixed control signals (for tasks such as moving a multi-legged walker) or have sensors integrated into them to provide a link to the outside world. There is a distinctive language developed for the construction of these circuits, which I'll attempt to explain a bit of below.
  
 ==Nv Neuron== ==Nv Neuron==
  
-One of the simplest BEAM components is the nv neuron, which consists of a capacitor, resistor and inverter arranged so they form a 1st order high pass filter with it's output inverted. In BEAM robotics, circuits are considered active when the output is low - this circuit will output pulses for a constant time (set by the values of the capacitor and resistor) when the input changes voltage.+{{http://www.pawfal.org/dave/images/beam/nvneuron-schematic.png}} 
 + 
 +One of the simplest BEAM components is the nv neuron, which consists of a capacitor, resistor and inverter arranged so they form a 1st order high pass filter with it's output inverted. In BEAM robotics, circuits are considered active when the output is low - this circuit will output low pulses for a constant time (set by the values of the capacitor and resistor) when the input changes voltage. 
 + 
 +{{http://www.pawfal.org/dave/images/beam/nvneuron.jpg}} 
 + 
 +An Nv neuron in the breadboard with a large capacitor, to make the pulse easier for a human to see. The inverter is provided by the 7404 hex inverter, which contains 6 logical NOT gates that we subvert for non-digital means. 
 + 
 +{{http://www.pawfal.org/dave/images/beam/7404.png}} 
 + 
 +Schematic of the 7404 
 + 
 +==Nv Neuron Array/Grounded Bicore==
  
 Nv neurons can be stacked together in arrays, where signals will be propagated slowly along them. Nv neurons can be stacked together in arrays, where signals will be propagated slowly along them.
 +
 +{{http://www.pawfal.org/dave/images/beam/nvchain-schematic.png}}
 +
 +With a simple modification, the output of the second Nv neuron can be fed into the input of the first. This forms a simple oscillator - what BEAM robot builders refer to as a grounded bicore.
 +
 +{{http://www.pawfal.org/dave/images/beam/grounded-schematic.png}}
 +
 +{{http://www.pawfal.org/dave/images/beam/grounded.jpg}}
 +
 +These bicores are the workhorses of BEAM robot brains, and are used to provide oscillating signals which can be controlled from other Nv neurons, or directly from sensor input.
 +
 +==Suspended Bicore==
 +
 +With some modifications, it's possible to greatly simplify the grounded bicore into the following form:
 +
 +{{http://www.pawfal.org/dave/images/beam/bicore-schematic.png}}
 +
 +{{http://www.pawfal.org/dave/images/beam/bicore.jpg}}
 +
 +By playing with the values of the components, different oscillation patterns can be made.
 +
 +===Solar Engines===
  
 ===BEAM types=== ===BEAM types===
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 ===Links=== ===Links===
  
 +  * Mark Tilden's robots: [[http://www.beam-online.com/Robots/Galleria_other/tilden.html]]
 +  * Some more example robots: [[http://www.xs4all.nl/~sbolt/e-index.html]]
 +  * For more detail, go to the BEAM wiki: [[http://www.beam-wiki.org/wiki/Main_Page]]
 +  * Solarbotics is the BEAM community server: [[http://www.solarbotics.net/]]
 +  * The BEAM web ring: [[http://v.webring.com/hub?ring=beamring]]
  
  • beam_robotics.txt
  • Last modified: 2009-01-12 10:28
  • by davegriffiths